ORIGINAL ARTICLE
The Relationship of Pain and Nausea in Postoperative Patients for 1 Week After Ambulatory Surgery Jan Odom-Forren, PhD, RN, CPAN, FAAN,* Mary K. Rayens, PhD,* Yevgeniya Gokun, MS,* Leena Jalota, MD,w Oliver Radke, MD, PhD, DEAA, MHBA,zy Vallire Hooper, PhD, RN, CPAN, FAAN,8 Amanda T. Wiggins, PhD,* and Christian C. Apfel, PhD, MDz
Objectives: The purpose of this study was to determine if pain level was associated with demographic or surgery-specific characteristics among patients recovering from ambulatory surgery; and to assess the relationship between pain level and nausea over the 7-day postoperative period, controlling for demographic and surgery-related covariates. Materials and Methods: This longitudinal study assessed the pain and nausea of 248 eligible patients during the day of surgery (DOS) and the 7 days following ambulatory surgery. Postoperative data were assessed using standardized questions about severity of pain and nausea symptoms. Participants who had a cumulative pain score of Z24 over the 8-day period were categorized as having high pain. Repeated-measures analysis of variance was used to assess differences in nausea by pain group over time, controlling for demographic, surgical variables, and antiemetic and analgesic use. Results: There were significant differences between 2 pain groups in age, surgical procedure, cumulative morphine equivalent dose, and use of antiemetics postdischarge. The longitudinal analysis demonstrated that patients in the high-pain group reported a greater degree of nausea on DOS and on each of the first 5 days postsurgery, controlling for differences in age, sex, education, use of antiemetics presurgery and postsurgery, use of acetaminophen postsurgery, daily morphine equivalent dose, and surgical procedure. Discussion: Younger patients and those receiving orthopedic procedures may be at greatest risk for postoperative pain. Patients with high pain reported a significantly greater degree of nausea on DOS through the first 5 days postdischarge. As the majority of surgeries are now conducted in the ambulatory setting, it is imperative that we determine pain management regimens and patient education
Received for publication April 3, 2014; revised November 12, 2014; accepted October 6, 2014. From the *College of Nursing, University of Kentucky, Lexington, KY; wUniversity of California; zDepartment of Anesthesia and Perioperative Care, University of California, San Francisco General Hospital; zAssociate Adjunct Professor, Department of Epidemiology & Biostatistics, University of California, San Francisco, CA; yDepartment of Anesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden at the TU Dresden, Fetscherstr, Dresden; and 8Medical College of Georgia, Augusta, GA. Present address: Leena Jalota, MD, Clinical Fellow, Department of Pulmonary and Critical Care, UCSF Fresno, Fresno, CA. Present address: Vallire Hooper, PhD, RN, CPAN, FAAN, Nursing Research, Mission Health System, Asheville, NC. Supported by Dr Apfel’s Perioperative Research Core, University of California, San Francisco, CA. The authors declare no conflict of interest. Reprints: Jan Odom-Forren, PhD, RN, CPAN, FAAN, University of Kentucky, College of Nursing 535, 760 Rose Street Lexington, KY 40536-0232 (e-mail: [email protected]). Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/AJP.0000000000000170
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practices that will allow for a more comfortable recovery for our patients. Key Words: ambulatory surgery, postoperative pain, postoperative nausea, day surgery
(Clin J Pain 2015;31:845–851)
A
pproximately 60% of all surgeries in the United States are performed in the ambulatory setting, involving over 34 million patients in 53 million procedures annually.1,2 Patients who undergo ambulatory surgery often have less efficient access to health care providers after discharge and subsequently suffer from complications, such as pain and nausea, silently at home.3–5 Postoperative pain occurs at a high incidence after ambulatory surgery with many patients reporting moderate to severe pain.6,7 Pain significantly interferes with normal activity after surgery8,9 and is one of the most frequently cited causes of unplanned admission after ambulatory surgery.10 Pain is the most frequent home symptom reported by adult ambulatory surgery patients and the main reason for unplanned health care contact.7,11,12 At least one third of patients who undergo ambulatory surgery will also experience postdischarge nausea and/or vomiting (PDNV).3,13–15 Patients with PDNV have the potential for morbidity and rehospitalization, and the presence of PDNV can adversely affect patient satisfaction with care.16–20 Historically, postoperative pain has been related to emesis and nausea.21,22 In a study of 175 ambulatory surgery patients, Pavlin et al23 found that patient satisfaction with care was negatively correlated to pain and nausea. Interestingly, patients rate nausea and vomiting postoperatively as worse than postoperative pain.24 Horvath,25 however, determined that pain was the single most significant predictor of delayed recovery in ambulatory gynecologic laparoscopic surgery. Readmission to the hospital may occur, with persistent pain mentioned as a common cause.26,27 The purpose of this study was to determine if postoperative pain level was associated with demographic or surgery-specific characteristics in a sample of 248 participants recovering from ambulatory surgery; and to assess the relationship between high pain and nausea over the 7-day postoperative period in this group, controlling for demographic and surgery-specific covariates. It was hypothesized that high pain would be associated with demographics and surgeryrelated variables, and that degree of pain would be related to nausea over time, even when controlling for personal and surgical variables. www.clinicalpain.com |
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MATERIALS AND METHODS
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Time
Design and Sample This longitudinal study assessed pain and nausea during the day of surgery (DOS) and the 7 days that followed. It is a secondary analysis of data from a larger study.13,14 Eligible patients were recruited consecutively from the preadmission testing unit or immediately before surgery in the preoperative holding area in 2 facilities. Inclusion criteria were outpatient surgery requiring general anesthesia, use of an endotracheal tube or laryngeal mask airway, and age greater than 18. Patients were excluded if they did not speak English, were pregnant or had persistent nausea before anesthesia, required an overnight stay, or required only regional anesthesia for the procedure.13,14 Institutional Review Boards of both facilities approved the study, and informed consent was obtained from 260 patients; 248 patients completed the 7-day diary and were used in this study. Prior analysis with this sample revealed that in the first 7 days following discharge, the incidence of nausea and emesis were 57% and 19%, respectively.14
Consecutive days postsurgery were evaluated in this study starting with day 0 (defined as day of surgery, or DOS) and ending with day 7 (the seventh postsurgical day).
Use of Antiemetics Antiemetic use during the perioperative period was assessed from the medical record and recorded as yes/no depending on whether this was included in their medications during this time. Similarly, participants were asked on each of the 7 assessment days following surgery to document usage of any antiemetics on the patient diary; this was recorded as yes/ no for each patient depending on whether there was any postdischarge use of these medications.
Regional Block A binary variable was used to record whether the patient received a regional block as part of their perioperative anesthesia. This was based on chart review and was recorded.
Morphine Equivalent Dose
Procedures Participants were asked to answer questions about their demographic characteristics, medical and surgeryrelated history, and to rate the perceived severity of both pain and nausea on ordinal scales. The treating anesthesia provider and surgeon determined the preferred anesthesia and medical treatment of the patient to reflect real-life conditions and current clinical practice in the United States.13,14 Clinical perioperative data (eg, use of volatile anesthetics, type and dose of opioids, duration of anesthesia, type of surgery, and type and dose of antiemetics) were obtained from the patient charts. Postoperative data were assessed using standardized questions about severity of pain and nausea symptoms per time interval on an 11point numeric rating scale. The initial survey was completed before surgery and postoperatively in the postanesthesia care unit, whereas those for days 1 to 7 postdischarge were included in a diary for the patient to take home and complete there.13,14 At the time of consent, participants were informed that an investigator would call to answer any questions about documentation of postoperative symptoms on day 1 and 2 following discharge, and again on day 7 when patients were also reminded with a phone call to mail the diary back to the investigator in a self-addressed, stamped envelope. Upon return of the diary, patients received a $10 gift card in the mail.
Postdischarge Use of Acetaminophen In addition to assessing patient use of opioids on each day postdischarge (to determine morphine equivalent dosage), they were also asked whether they had taken any acetaminophen (Tylenol), and this was recorded as a yes/no during the postdischarge period.
Surgical Procedure Type of procedure was initially categorized “Breast,” “Cholecystectomy,” “Cystoscopy,” “Dilation and Curettage (D&C),” “Ear, Nose and Throat (ENT),” “Hernia,” “Knee Arthroscopy,” “Other general surgery,” “Other gynecologic surgery,” “Other orthopedic surgery,” “Prostate,” and “Upper Extremity.” To avoid small or empty cell sizes in the analysis, some categories were combined. The resulting 4-level variable and consisted of these categories: “D&C/Gynecologic,” “General/Cholecystectomy/Breast/ENT/ Hernia,” “Knee/Ortho/Upper,” and “Cystoscopy/Prostate.”
Surgical Approach
Measures Sociodemographic and Personal Factors Sociodemographic factors of interest included age (y), sex, and education. Smoking status and recruitment site (namely facility) were also recorded. Education was assessed by participant response to the highest educational level completed with the possible response options of “Some High School,” “High School Graduate,” “College,” “Master’s Degree,” and “Doctoral Degree.” Education was dichotomized as “High School Graduate or below” and “Postsecondary” before analysis. Smoking status was assessed as a binary variable, current smoker versus nonsmoker. Facility was recorded as 1 or 2, using the numbering convention set for the 2 recruitment sites.
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Total morphine equivalent dosage28 was calculated as sum over 8 time periods (from DOS through the seventh postsurgical day). The square root transformation was applied to this variable before analysis as the raw values were skewed to the right. For the repeated-measures model to assess the relationship between pain and nausea over time, the square root of the daily morphine equivalent was used as a time-dependent covariate in the analysis.
The approach was assessed with the possible response options of “Conventional,” “Arthroscopic,” “Endoscopic,” and “Laparoscopic.”
Level of Pain Pain was measured on an 11-point Likert scale ranging from 0 = “None” to 10 = “Worst.” Participants were divided into 2 groups based on their cumulative pain score during the 8-day study period. As the median pain score for days 2 and 3 postsurgery was 3, this cutoff was used as an indicator of high versus low pain on any assessment day. Participants whose cumulative score over the 8-day period was Z24 were classified as high-pain group, whereas those with scores of r23 were classified in the low-pain group.
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FIGURE 1. Mean daily pain scores for each of the 2 pain groups over time (N = 248). DOS indicates day of surgery.
The high-pain group included both those with persistent pain across the 8-day period (38% of patients in the highpain group had pain scores of Z3 all 8 assessments), as well as those with extreme pain on several days or more. The mean pain scores for each of the 8 days of the study by pain group are shown in Figure 1. The contrast between these groups is striking, given the lowest mean for the highpain group is greater than the highest mean for the low-pain group; this provides justification for dividing the groups in this way.
Nausea Longitudinal measurements of nausea were evaluated once daily from DOS through the seventh postsurgical day; each measurement was coded on an 11-point Likert scale of 0 = “None” to 10 = “Worst.”
Data Analysis Descriptive analysis, including means and SDs or frequency distributions, was done to summarize all study variables. Two-group comparisons of study variables by binary pain group indicator (high vs. low) were accomplished using regression models, including linear, logistic, or multinomial, as appropriate. Each of the models included the age, sex, education, smoking status, and facility as covariates; for the comparison of these variables between pain groups, the variable being compared was omitted as a covariate. For the group comparisons of surgical procedure and surgical approach, sex was omitted as a covariate due to its association with both outcomes (ie, gynecologic procedures and the approaches most typically used for them). Linear regression was used for the pain group comparison of age and for the comparison of the square root of total morphine equivalent dose; logistic was used for sex, education, smoking status, facility, use of perioperative antiemetics, use of regional block, use of postdischarge antiemetics, use of postoperative acetaminophen; and multinomial was used for surgical procedure and surgical approach. Pearson product moment correlation was used to test for associations between pain and nausea at each assessment day. A mixed-effects repeated-measures model, estimated using the MIXED procedure in SAS, was used to evaluate longitudinal comparisons between binary pain indicator and the outcome of nausea. The fixed effects for this model included pain group (high vs. low) and time (days 0 to 7) as well as their interaction. The participants were nested in facilities to account for correlations among patients being treated at the same surgical site. The demographic and clinical variables of age, sex, education, and square root of daily Copyright
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morphine equivalent dose were included as covariates, and surgical procedure (with 4 levels) was added to the model as an additional fixed effect, as a control for differences among patients with different procedures. Surgical approach was not included because there was a statistically significant association between approach and procedure type (w2 = 297.7, P < 0.0001). Other surgery-specific indicators included as control variables were use of antiemetics during perioperative period, antiemetics during postdischarge period, use of regional block, and use of acetaminophen during postdischarge period. In addition to the main effects, covariates, and the interaction between pain group and time, the interactions of time with both surgical approach and morphine equivalent dose were included as additional control variables. Post hoc pairwise comparisons between pain groups for fixed timepoints were made using contrast statements to determine mean differences and 95% confidence intervals for these differences. All analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC); an a-level of 0.05 was used throughout.
RESULTS The mean age of the 248 participants was 52.3 (SD = 14.7); the range of age was 19 to 87. Most respondents were female (71%) and 58% had postsecondary education. Fifteen percent of participants were current smokers. The majority of participants (53%) had general, cholecystectomy, breast, ENT, or hernia repair as the surgical procedure, and 37% had conventional surgical approach. The mean morphine equivalent dose (based on untransformed data) was 55.0 mg (SD = 122.0) and the median dose was 17.5 mg. The interquartile range was 2.5 to 60.0 mg, and the full range of morphine equivalent doses was from 0.0 to 1360.0 mg. Sixtytwo percent of the patients in this study received some type of regional block before or during surgery. The analgesics taken postdischarge included hydrocodone (35%), oxycodone (45%), and acetaminophen alone (61%); no other analgesics were recorded as used by patients at home. The total is >100% as patients may have used different pain relief strategies on different days. Overall, only 15% of patients used an antiemetic after discharge home, including promethazine (13%), and diphenhydramine, dexamethasone, or ondansetron (< 1% for each drug). As shown in Table 1, there were significant differences between 2 pain groups in age, surgical procedures, morphine equivalent dose, and postoperative acetaminophen use, controlling for demographic variables, smoking status, and facility. Respondents in the high-pain group were younger compared with those in the low-pain group (P = 0.002). More than half of those in the knee arthroscopy, orthopedic, or upper extremity surgical procedure group were in the high-pain group (55%), compared with smaller percentages of patients in this pain group for general procedures (44%), D&C/gynecologic (13%) or cystoscopy/prostate (8%; P = 0.001 for the pain group comparison). Respondents in the high-pain group had higher transformed mean morphine equivalent dosage summed over all the time periods (P < 0.001). Finally, those in the high-pain group were more likely to use acetaminophen one or more times during the postoperative period (73%) compared with the low-pain group (53%; P = 0.007 for the group comparison). The pain group comparisons of sex, education, and smoking status, facility, surgical approach, and antiemetic use both during
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TABLE 1. Pain Group Comparisons of Demographic and Clinical Characteristics, Controlling for Age, Sex, Education, Smoking Status, and Facility* (N = 248)
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TABLE 2. Significance of Covariates and Main and Interaction Effects in the Mixed-Effects Repeated-Measures Model With Daily Nausea Score as Outcome (N = 248)
Pain Groups (n [%]) Variables
High Pain (n = 97)
Low Pain (n = 151)
Age Mean (SD) 48.37 (15.24) 54.83 (13.80) Sex Male 31 (32.0) 40 (26.5) Female 66 (68.0) 111 (73.5) Education HS or below 38 (40.0) 58 (39.7) Postsecondary 57 (60.0) 88 (60.3) Smoking status Nonsmoker 79 (81.4) 132 (87.4) Smoker 18 (18.6) 19 (12.6) Facility Facility 1 28 (28.9) 27 (17.9) Facility 2 69 (71.1) 124 (82.1) Surgical procedure Generalw 58 (59.8) 74 (49.0) D&C/GYNz 6 (6.2) 39 (25.8) Knee/ortho/upper 32 (33.0) 26 (17.2) Cystoscopy/prostate 1 (1.0) 12 (8.0) Surgical approach Conventional 35 (36.1) 56 (37.1) Arthroscopic 29 (29.9) 20 (13.3) Endoscopic 3 (3.1) 37 (24.5) Laparoscopic 30 (30.9) 38 (25.2) Square root of cumulative morphine equivalent dosage (including all 8 d) Mean (SD) 7.84 (6.17) 3.68 (3.67) Perioperative antiemetic use Yes 85 (87.6) 130 (86.1) No 12 (12.4) 21 (13.9) Regional block during surgery Yes 62 (63.9) 92 (60.9) No 35 (36.1) 59 (39.1) Postdischarge antiemetic use Yes 21 (21.7) 16 (10.6) No 76 (78.3) 135 (89.4) Postdischarge acetaminophen use Yes 71 (73.2) 80 (53.0) No 26 (26.8) 71 (47.0) Cumulative pain score (including all 8 d) Mean (SD) 40.57 (13.06) 10.83 (7.07)
Variables
P 0.002 0.14 0.50 0.35 0.34 0.001
Age Female Postsecondary education Smoker Surgical procedure Daily morphine equivalent dose Perioperative antiemetic use Regional block used during surgery Postdischarge antiemetic use Postdischarge acetaminophen use Pain group Time (d) Pain grouptime Surgical type time Morphine equivalent dose time
5.4 2.8 < 0.1 2.8 < 0.1 2.0 0.1 3.3
(1) (1) (1) (1) (3) (1) (1) (1)
24.6 < 0.1 14.2 5.9 2.5 1.3 2.2
(1) (1) (1) (7) (7) (21) (7)
P 0.020 0.095 0.94 0.093 0.98 0.15 0.74 0.068 < 0.001 0.91 < 0.001 < 0.001 0.014 0.20 0.029
*Effects significant at the alpha level of 0.05 are bolded. Note: The denominator degrees of freedom = 1864 for all tests.
0.69
< 0.001 0.95 0.20 0.057 0.007 y
*Pain group comparisons made using linear, logistic, or multinomial regression, with age, gender, education, smoking status, and facility included as covariates; models with one of the covariates as the outcome did not contain that variable as a predictor. wIncludes general; cholecystectomy; breast; ear, nose, and throat (ENT); and hernia surgical procedures zD&C = dilation and curettage; GYN = gynecologic. yGroup comparison for this variable was not done as the groups were defined by cumulative pain level.
perioperative period and postdischarge, as well as use of a regional block were not statistically significant. Although not compared statistically as these scores were used to define the 2 pain groups, the mean cumulative pain score over the 8 assessments was 40.6 (SD = 13.1) in the high-pain group, relative to 10.8 (SD = 7.1) in the lowpain group (Table 1). Not surprisingly, there was a significant correlation between pain and nausea at each of the 8 assessments (DOS and each day of the 7 d after). The correlation coefficients ranged from 0.24 to 0.37 and all
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F Value (Numerator Degrees of Freedom)
were significant with P < 0.001; the mean correlation across the 8 days was 0.30, indicating a moderate association between pain and nausea. In the mixed-effects repeated-measures model (Table 2), the significant main effects and covariates were age, pain group, time, the indicators for peiroperative antiemetics and regional block, the indicators for postdischarge antiemetics and acetaminophen, and the interactions of time with each of pain group and morphine equivalent dose. Given the significant interaction effects, the main effects of pain group and time are not interpretable so post hoc analysis was not conducted for these. The mean pain group differences in nausea for each time, along with 95% confidence intervals for the mean differences, are displayed in Figure 2. This post hoc analysis of the significant time by pain group interaction includes all of the measured personal and surgery-specific covariates that may influence the relationship between pain and nausea. The largest group difference in mean nausea was at day 2 postdischarge: On average, the nausea scores for the highpain group exceeded those of the low-pain group by 1.21. By day 7 postdischarge, this mean difference had decreased
FIGURE 2. Mean differences in daily nausea scores between high-pain and low-pain groups, with 95% confidence intervals; from day of surgery to day 7 postsurgery. DOS indicates day of surgery.
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to 0.01. There was a gradual increase in the mean group difference in nausea between high-pain and low-pain groups over time, starting from DOS and continuing through day 2 postdischarge; this was followed by a gradual decrease in the discrepancy in nausea levels between the 2 groups, starting with day 3. As indicated by the limits of the confidence intervals for the mean difference, the high-pain group significantly exceeded the low-pain group in average nausea on DOS and on days 1 to 5 following discharge. The group differences on days 6 and 7 were not significant.
DISCUSSION The main finding of this study was that patients with high pain reported a greater degree of nausea on DOS and on each of the first 6 days postsurgery even when controlling for differences in age, sex, education, morphine equivalent dose, surgical approach, use of a regional block, use of antiemetics preoperatively and postdischarge, and postdischarge use of acetaminophen. The mean nausea scores of the high-pain group did not decrease to the level of those in the low-pain group until postsurgery day 6. Similar to other studies, we found that pain was significant for nearly 40% of the sample during the week following ambulatory surgery. McGrath et al11 determined that 30% of ambulatory surgery patients have moderate to severe pain after 24 hours. Others have determined that moderate to severe pain (Z4 on a scale of 0 to 10) is experienced by many patients after 48 hours,23 up to 4 days,6 4 weeks,29 and even up to 3 months.8 In a descriptive study of incidence and severity of symptoms after ambulatory surgery, pain was the most frequent symptom, often at the moderate to severe level.7,30 In this study, patients who were younger or who had an orthopedic procedure were more likely to experience high pain than the patients who had were older or had a nonorthopedic procedure, controlling for patient characteristics. Past studies have found that patients who had severe pain were significantly younger than those without it.31–33 Other researchers have also found that patients undergoing orthopedic surgery related higher pain scores. Orthopedic patients have reported more pain and nausea at 72 hours than at any other earlier time period and required a continued need for nursing contact and support.34 Chung et al31 found that orthopedic patients had more severe pain than general surgery patients and that shoulder surgery was the most painful orthopedic surgery. McGrath et al11 found that 4 of the 7 most painful surgeries in the ambulatory surgery setting were orthopedic surgeries: shoulder, elbow/hand, ankle, and knee. Watt-Watson et al26 found that patients who had received shoulder surgeries had the most pain for up to a week. Gramke et al6 also found that orthopedic surgeries were one of the most painful procedures during the first 48 hours of recovery after ambulatory surgery. Controlling for demographics and smoking status, we found an association between cumulative consumption of opioids over the 8-day period (ie, dose in morphine equivalents), and pain level, with greater doses among patients in the high-pain group. This was the rationale for including daily morphine equivalent in the longitudinal analysis; we wanted to assess the relationship between pain and nausea controlling for differences in amount of opioid used. Interestingly, we did not find a relationship between smoking status and postoperative pain although previous studies have found that postoperative analgesic Copyright
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requirements tend to be higher for smokers than nonsmokers.35 We know that smokers deprived of nicotine typically require a greater amount of opiates in the first 48 hours36 and consumption of fentanyl tends to be higher for second-hand smokers than nonsmokers, but less than smokers.37 It is possible that our lack of association between smoking status and postoperative pain group was because of the small number of smokers in the study. There was a moderate correlation between daily pain and nausea scores starting with DOS and continuing through the week following surgery. This positive association was relatively consistent over the entire 8-day period. Andersen and Krohg21 determined that complete pain relief without relief of nausea is difficult as early as 1976; only 10% of patients complained of nausea without also complaining of pain. Chia et al22 determined that postoperative pain was an associative risk factor of emesis in female patients. When attempting to develop a better model to predict the patient’s risk for PONV, Sarin et al38 found that postoperative opioids were not associated with increased risk of PONV, but the level of postoperative pain was correlated with that risk. Other experts have theorized that postoperative pain and nausea are related, but it has been difficult to determine whether postoperative pain or postoperative opioids was the cause of increased nausea.38,39 The primary finding of this study was that those with higher pain scores (ie, members of the high-pain group) had significantly more nausea starting on DOS and this continued each day until the sixth day after surgery, compared with patients who had lower pain scores. This relationship was assessed with a variety of personal and surgery-related variables included in the longitudinal model as covariates. Pain and nausea are the most frequently reported symptoms after surgery.23,40 When asked which symptoms they would most like avoid, patients chose avoidance of postoperative pain and nausea as 2 of the top 3 priorities.41 Pain and nausea were also the top 2 choices when a panel of anesthesiologists was asked which anesthesia outcome was most important to avoid.24 Patients who experienced nausea and vomiting in the past were willing to pay US$73 and US$100 to prevent the symptoms in the future. It is clear that some patients continue to suffer with pain and nausea at home for at least a week after surgery.4 The findings of this study underscore the importance of pain management following ambulatory surgery. By promoting pain management, we can better assure that the patient has a successful recovery. Rosen et al8 found that pain level at 48 hours predicts a return to normal activity at 7 days. Patient satisfaction with the perioperative experience is correlated negatively to pain and nausea.23 Further research is needed to identify pain management regimens that include pharmaceutical as well as nonpharmacologic methods of pain control. It would seem that better pain control would result in less nausea experienced by the patient; however, we do not know whether a more personalized pain management regimen would have made a difference in the present study or whether a patient education program that focused on pain management would have made an impact. However, it is likely that appropriate management of pain can contribute to a lower incidence of both pain and nausea. It has been noted that some patients do not take their opioids at home after ambulatory surgery because of the belief that the medication contributed to the nausea they were experiencing.42 Patient education could correct inaccurate beliefs about the use of analgesics and contribute to better pain management.43 There has been
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limited research conducted to capture patient experiences at home.44 This study gives us a glimpse of the pain and nausea trajectories experienced by patients after ambulatory surgery. There are several limitations to this study. This was an observational study; patients were not randomized to standardized anesthesia regimen or for type of surgery. Degree of preoperative pain was not assessed in our study and may have contributed to postoperative pain perception and scores. Future research in this area will be enhanced by controlling for preoperative pain scores. All postdischarge medication data were collected using self-report assessments of actual use; medication adherence using an objective tracking system (such as Medication Event Monitoring System) was not assessed. In addition, we did not measure patient perceptions and beliefs on use of pain medications. Finally, although we did track the use of antiemetics during the perioperative period, and postdischarge use of both antiemetics and acetaminophen, we did not compile these by accumulated daily dose. Future studies will benefit from having a more detailed summary of the links between the use of analgesics and antiemetics by dose. Another aspect for further study will be the relationship between prescribed use and adherence, and how this relates to assessed pain and nausea.
CONCLUSIONS This study determined several personal and surgical factors that are related to pain level, including age, surgical procedure total morphine equivalent, and postdischarge use of antiemetics. Patients with high pain (more severe pain during the postoperative period) reported a greater degree of nausea on DOS and on each of the first 5 days postsurgery even when controlling for differences in age, sex, education, morphine equivalent dose and surgical approach, and other medications (antiemetics and acetaminophen) taken preoperatively and after discharge. Young patients and patients undergoing orthopedic procedures tended to have higher pain ratings, controlling for demographic variables and smoking status. With the majority of surgeries conducted in the ambulatory setting, it is imperative that we determine pain management regimens and patient education practices that will allow for a more comfortable recovery for our patients. REFERENCES 1. Cullen K, Hall M, Golosinskiy A. Ambulatory surgery in the United States, 2006. National Health Statistics Reports. Centers for Disease Control and Prevention. Hyattsville, MD. no. 11, Revised. Pp. 1-28. Available at: http://www.cdc.gov/ nchs/data/nhsr/nhsr011.pdf. Accessed November 5, 2014. 2. Russo A, Elixhauser A, Steiner C, et al. Hospital-based Ambulatory Surgery, 2007. Rockville, MD: Agency for Healthcare Research and Quality; 2010. 3. Gupta A, Wu C, Elkassabany N, et al. Does the routine prophylactic use of antiemetics affect the incidence of postdischarge nausea and vomiting following ambulatory surgery?: a systematic review of randomized controlled trials. Anesthesiology. 2003;99:488–495. 4. Lipp A, Kaliappan A. Focus on quality: managing pain and PONV in day surgery. Curr Anaesth Crit Care. 2007;18:200–2007. 5. Kavanagh T, Hu P, Minogue S. Daycase laparoscopic cholecystectomy: a prospective study of post-discharge pain, analgesic and antiemetic requirements. Ir J Med Sci. 2008; 177:111–115. 6. Gramke H, di Rijke J, van Kleefe M, et al. The prevalence of postoperative pain in a cross-sectional group of patients after day-case surgery in a university hospital. Clin J Pain. 2007;23:543–548.
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7. Mattila K, Toivonen J, Janhunen L, et al. Postdischarge symptoms after ambulatory surgery: first-week incidence, intensity, and risk factors. Anesth Analg. 2005;101:1643–1650. 8. Rosen H, Bergh I, Oden A, et al. Patients’ experiences of pain following day surgery—at 48 hours, seven days and three months. Open Nurs J. 2011;5:52–59. 9. Gudex C, Sorensen J, Clausen I. Day surgery for gynaecological laparoscopy: clinical results from an RCT. Ambul Surg. 2006;12:151–156. 10. Morales R, Esteve N, Casa I, et al. Why are ambulatory surgical patients admitted to hospital?: prospective study. Ambul Surg. 2002;9:197–205. 11. McGrath B, Elgendy H, Chung F, et al. Thirty percent of patients have moderate to severe pain 24 hr after ambulatory surgery: a survey of 5703 patients. Can J Anaesth. 2004;51:888–891. 12. Pavlin D, Chen C, Penaloza D, et al. Pain as a factor complicating recovery and discharge after ambulatory surgery. Anesth Analg. 2002;95:627–634. 13. Apfel C, Philip B, Cakmakkaya O, et al. Who is at risk for postdischarge nausea and vomiting after ambulatory surgery. Anesthesiology. 2012;117:475–486. 14. Odom-Forren J, Jalota L, Moser D, et al. Incidence and predictors of post discharge nausea and vomiting in a 7 day population. J Clin Anesth. 2013;25:551–559. 15. Wu C, Berenholtz S, Pronovost P, et al. Systematic review and analysis of postdischarge symptoms after outpatient surgery. Anesthesiology. 2002;96:994–1003. 16. Candiotti K, Kovac A, Melson T, et al. Palonosetron 04-06 Study Group. A randomized, double-blind study to evaluate the efficacy and safety of three different doses of palonosetron versus placebo for preventing postoperative nausea and vomiting. Anesth Analg. 2008;107:445–451. 17. Kapur P. The big “little problem”. Anesth Analg. 1991;73:243–245. 18. Odom-Forren J, Fetzer S, Moser D. Evidence-based interventions for post discharge nausea and vomiting: a review of the literature. J Perianesth Nurs. 2006;21:411–430. 19. White P, O’Hara J, Roberson C, et al. The impact of current antiemetic practices on patient outcomes: a prospective study on high-risk patients. Anesth Analg. 2008;107:452–458. 20. Pan PH, Lee SC, Harris LC. Antiemetic prophylaxis for postdischarge nausea and vomiting and impact on functional quality of living during recovery in patients with high emetic risks: a prospective, randomized, double-blind comparison of two prophylactic antiemetic regimens. Anesth Analg. 2008;107:429–438. 21. Anderson R, Krohg K. Pain as a major cause of postoperative nausea. Can Anaesth Soc J. 1976;23:366–369. 22. Chia Y, Kuo M, Liu K, et al. Does postoperative pain induce emesis? Clin J Pain. 2002;18:317–323. 23. Pavlin D, Chen C, Penaloza D, et al. A survey of pain and other symptoms that affect the recovery process after discharge from an ambulatory surgery unit. J Clin Anesth. 2004;16: 200–206. 24. Macario A, Weinger M, Carney S, et al. Which clinical anesthesia outcomes are important to avoid? The perspective of patients. Anesth Analg. 1999;89:652–658. 25. Horvath K. Postoperative recovery at home after ambulatory gynecologic laparoscopic surgery. J Perianesth Nurs. 2003; 18:324–334. 26. Watt-Watson J, Chung F, Chan V, et al. Pain management following discharge after ambulatory same-day surgery. J Nurs Manag. 2004;12:153–161. 27. Young J, O’Connell B, McGregor S. Day surgery patients’ convalescence at home: does enhanced discharge education make a difference? Nurs Health Sci. 2000;2:29–39. 28. Vieweg W, Lipps W, Fernandez A. Opioids and methadone equivalents for clinicians. Prim Care Companion J Clin Psychiatry. 2005;7:86–88. 29. Brattwall M, Warren Stomberg M, Rawal N, et al. Patients’ assessment of 4-week recovery after ambulatory surgery. Acta Anaesthesiol Scand. 2011;55:92–98. 30. Susilahti H, Suomienen T, Leino-Kilpi H. Recovery of Finnish short-stay surgery patients. Medsurg Nurs. 2004;13:236–335.
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31. Chung F, Ritchie E, Su J. Postoperative pain in ambulatory surgery. Anesth Analg. 1997;85:808–816. 32. Marco C, Nagel J, Klink E, et al. Factors associated with selfreported pain scores among ED patients. Am J Emerg Med. 2012;30:331–337. 33. Yellen E, Davis G. Patient satisfaction in ambulatory surgery. AORN J. 2001;74:483–498. 34. Flanagan J, Jones D. High-frequency nursing diagnoses following same-day knee arthroscopy. Int J Nurs Terminol Classif. 2009;20:89–95. 35. Shi Y, Weingarten T, Mantilla C, et al. Smoking and pain: pathophysiology and clinical implications. Anesthesiology. 2010; 113:977–992. 36. Creekmore F, Lugo R, Weiland K. Postoperative opiate analgesia requirements of smokers and nonsmokers. Ann Pharmacother. 2004;38:949–953. 37. Aydogan M, Ozturk E, Erdogan M, et al. The effects of secondhand smoke on postoperative pain and fentanyl consumption. J Anesth. 2013;27:569–574.
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38. Sarin P, Urman R, Ohno-Machado L. An improved model for predicting postoperative nausea and vomiting in ambulatory surgery patients using physician-modifiable risk factors. J Am Med Inform Assoc. 2012;19:995–1002. 39. Gan TJ. Risk factors for postoperative nausea and vomiting. Anesth Analg. 2006;102:1884–1898. 40. Rosen H, Clabo L, Martensson L. Symptoms following day surgery: a review of the literature. J Adv Periop Care. 2009;4: 7–18. 41. Jenkins K, Grady D, Wong J, et al. Post-operative recovery: day surgery patients’ preferences. Br J Anaesth. 2001;86: 272–274. 42. Fetzer S, Hand M, Bouchard P, et al. Self-care activities for postdischarge nausea and vomiting. J Perianesth Nurs. 2005;20:249–254. 43. Older C, Carr E, Layzell M. Making sense of patients’ use of analgesics following day case surgery. J Adv Nurs. 2010;20:249–254. 44. Erkal S. Patients’ experiences at home after day case cystoscopy. J Clin Nurs. 2007;16:1118–1124.
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The Relationship of Pain and Nausea in Postoperative Patients for 1 Week After Ambulatory Surgery Jan Odom-Forren, PhD, RN, CPAN, FAAN,* Mary K. Rayens, PhD,* Yevgeniya Gokun, MS,* Leena Jalota, MD,w Oliver Radke, MD, PhD, DEAA, MHBA,zy Vallire Hooper, PhD, RN, CPAN, FAAN,8 Amanda T. Wiggins, PhD,* and Christian C. Apfel, PhD, MDz
Objectives: The purpose of this study was to determine if pain level was associated with demographic or surgery-specific characteristics among patients recovering from ambulatory surgery; and to assess the relationship between pain level and nausea over the 7-day postoperative period, controlling for demographic and surgery-related covariates. Materials and Methods: This longitudinal study assessed the pain and nausea of 248 eligible patients during the day of surgery (DOS) and the 7 days following ambulatory surgery. Postoperative data were assessed using standardized questions about severity of pain and nausea symptoms. Participants who had a cumulative pain score of Z24 over the 8-day period were categorized as having high pain. Repeated-measures analysis of variance was used to assess differences in nausea by pain group over time, controlling for demographic, surgical variables, and antiemetic and analgesic use. Results: There were significant differences between 2 pain groups in age, surgical procedure, cumulative morphine equivalent dose, and use of antiemetics postdischarge. The longitudinal analysis demonstrated that patients in the high-pain group reported a greater degree of nausea on DOS and on each of the first 5 days postsurgery, controlling for differences in age, sex, education, use of antiemetics presurgery and postsurgery, use of acetaminophen postsurgery, daily morphine equivalent dose, and surgical procedure. Discussion: Younger patients and those receiving orthopedic procedures may be at greatest risk for postoperative pain. Patients with high pain reported a significantly greater degree of nausea on DOS through the first 5 days postdischarge. As the majority of surgeries are now conducted in the ambulatory setting, it is imperative that we determine pain management regimens and patient education
Received for publication April 3, 2014; revised November 12, 2014; accepted October 6, 2014. From the *College of Nursing, University of Kentucky, Lexington, KY; wUniversity of California; zDepartment of Anesthesia and Perioperative Care, University of California, San Francisco General Hospital; zAssociate Adjunct Professor, Department of Epidemiology & Biostatistics, University of California, San Francisco, CA; yDepartment of Anesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus Dresden at the TU Dresden, Fetscherstr, Dresden; and 8Medical College of Georgia, Augusta, GA. Present address: Leena Jalota, MD, Clinical Fellow, Department of Pulmonary and Critical Care, UCSF Fresno, Fresno, CA. Present address: Vallire Hooper, PhD, RN, CPAN, FAAN, Nursing Research, Mission Health System, Asheville, NC. Supported by Dr Apfel’s Perioperative Research Core, University of California, San Francisco, CA. The authors declare no conflict of interest. Reprints: Jan Odom-Forren, PhD, RN, CPAN, FAAN, University of Kentucky, College of Nursing 535, 760 Rose Street Lexington, KY 40536-0232 (e-mail: [email protected]). Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/AJP.0000000000000170
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practices that will allow for a more comfortable recovery for our patients. Key Words: ambulatory surgery, postoperative pain, postoperative nausea, day surgery
(Clin J Pain 2015;31:845–851)
A
pproximately 60% of all surgeries in the United States are performed in the ambulatory setting, involving over 34 million patients in 53 million procedures annually.1,2 Patients who undergo ambulatory surgery often have less efficient access to health care providers after discharge and subsequently suffer from complications, such as pain and nausea, silently at home.3–5 Postoperative pain occurs at a high incidence after ambulatory surgery with many patients reporting moderate to severe pain.6,7 Pain significantly interferes with normal activity after surgery8,9 and is one of the most frequently cited causes of unplanned admission after ambulatory surgery.10 Pain is the most frequent home symptom reported by adult ambulatory surgery patients and the main reason for unplanned health care contact.7,11,12 At least one third of patients who undergo ambulatory surgery will also experience postdischarge nausea and/or vomiting (PDNV).3,13–15 Patients with PDNV have the potential for morbidity and rehospitalization, and the presence of PDNV can adversely affect patient satisfaction with care.16–20 Historically, postoperative pain has been related to emesis and nausea.21,22 In a study of 175 ambulatory surgery patients, Pavlin et al23 found that patient satisfaction with care was negatively correlated to pain and nausea. Interestingly, patients rate nausea and vomiting postoperatively as worse than postoperative pain.24 Horvath,25 however, determined that pain was the single most significant predictor of delayed recovery in ambulatory gynecologic laparoscopic surgery. Readmission to the hospital may occur, with persistent pain mentioned as a common cause.26,27 The purpose of this study was to determine if postoperative pain level was associated with demographic or surgery-specific characteristics in a sample of 248 participants recovering from ambulatory surgery; and to assess the relationship between high pain and nausea over the 7-day postoperative period in this group, controlling for demographic and surgery-specific covariates. It was hypothesized that high pain would be associated with demographics and surgeryrelated variables, and that degree of pain would be related to nausea over time, even when controlling for personal and surgical variables. www.clinicalpain.com |
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MATERIALS AND METHODS
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Time
Design and Sample This longitudinal study assessed pain and nausea during the day of surgery (DOS) and the 7 days that followed. It is a secondary analysis of data from a larger study.13,14 Eligible patients were recruited consecutively from the preadmission testing unit or immediately before surgery in the preoperative holding area in 2 facilities. Inclusion criteria were outpatient surgery requiring general anesthesia, use of an endotracheal tube or laryngeal mask airway, and age greater than 18. Patients were excluded if they did not speak English, were pregnant or had persistent nausea before anesthesia, required an overnight stay, or required only regional anesthesia for the procedure.13,14 Institutional Review Boards of both facilities approved the study, and informed consent was obtained from 260 patients; 248 patients completed the 7-day diary and were used in this study. Prior analysis with this sample revealed that in the first 7 days following discharge, the incidence of nausea and emesis were 57% and 19%, respectively.14
Consecutive days postsurgery were evaluated in this study starting with day 0 (defined as day of surgery, or DOS) and ending with day 7 (the seventh postsurgical day).
Use of Antiemetics Antiemetic use during the perioperative period was assessed from the medical record and recorded as yes/no depending on whether this was included in their medications during this time. Similarly, participants were asked on each of the 7 assessment days following surgery to document usage of any antiemetics on the patient diary; this was recorded as yes/ no for each patient depending on whether there was any postdischarge use of these medications.
Regional Block A binary variable was used to record whether the patient received a regional block as part of their perioperative anesthesia. This was based on chart review and was recorded.
Morphine Equivalent Dose
Procedures Participants were asked to answer questions about their demographic characteristics, medical and surgeryrelated history, and to rate the perceived severity of both pain and nausea on ordinal scales. The treating anesthesia provider and surgeon determined the preferred anesthesia and medical treatment of the patient to reflect real-life conditions and current clinical practice in the United States.13,14 Clinical perioperative data (eg, use of volatile anesthetics, type and dose of opioids, duration of anesthesia, type of surgery, and type and dose of antiemetics) were obtained from the patient charts. Postoperative data were assessed using standardized questions about severity of pain and nausea symptoms per time interval on an 11point numeric rating scale. The initial survey was completed before surgery and postoperatively in the postanesthesia care unit, whereas those for days 1 to 7 postdischarge were included in a diary for the patient to take home and complete there.13,14 At the time of consent, participants were informed that an investigator would call to answer any questions about documentation of postoperative symptoms on day 1 and 2 following discharge, and again on day 7 when patients were also reminded with a phone call to mail the diary back to the investigator in a self-addressed, stamped envelope. Upon return of the diary, patients received a $10 gift card in the mail.
Postdischarge Use of Acetaminophen In addition to assessing patient use of opioids on each day postdischarge (to determine morphine equivalent dosage), they were also asked whether they had taken any acetaminophen (Tylenol), and this was recorded as a yes/no during the postdischarge period.
Surgical Procedure Type of procedure was initially categorized “Breast,” “Cholecystectomy,” “Cystoscopy,” “Dilation and Curettage (D&C),” “Ear, Nose and Throat (ENT),” “Hernia,” “Knee Arthroscopy,” “Other general surgery,” “Other gynecologic surgery,” “Other orthopedic surgery,” “Prostate,” and “Upper Extremity.” To avoid small or empty cell sizes in the analysis, some categories were combined. The resulting 4-level variable and consisted of these categories: “D&C/Gynecologic,” “General/Cholecystectomy/Breast/ENT/ Hernia,” “Knee/Ortho/Upper,” and “Cystoscopy/Prostate.”
Surgical Approach
Measures Sociodemographic and Personal Factors Sociodemographic factors of interest included age (y), sex, and education. Smoking status and recruitment site (namely facility) were also recorded. Education was assessed by participant response to the highest educational level completed with the possible response options of “Some High School,” “High School Graduate,” “College,” “Master’s Degree,” and “Doctoral Degree.” Education was dichotomized as “High School Graduate or below” and “Postsecondary” before analysis. Smoking status was assessed as a binary variable, current smoker versus nonsmoker. Facility was recorded as 1 or 2, using the numbering convention set for the 2 recruitment sites.
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Total morphine equivalent dosage28 was calculated as sum over 8 time periods (from DOS through the seventh postsurgical day). The square root transformation was applied to this variable before analysis as the raw values were skewed to the right. For the repeated-measures model to assess the relationship between pain and nausea over time, the square root of the daily morphine equivalent was used as a time-dependent covariate in the analysis.
The approach was assessed with the possible response options of “Conventional,” “Arthroscopic,” “Endoscopic,” and “Laparoscopic.”
Level of Pain Pain was measured on an 11-point Likert scale ranging from 0 = “None” to 10 = “Worst.” Participants were divided into 2 groups based on their cumulative pain score during the 8-day study period. As the median pain score for days 2 and 3 postsurgery was 3, this cutoff was used as an indicator of high versus low pain on any assessment day. Participants whose cumulative score over the 8-day period was Z24 were classified as high-pain group, whereas those with scores of r23 were classified in the low-pain group.
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FIGURE 1. Mean daily pain scores for each of the 2 pain groups over time (N = 248). DOS indicates day of surgery.
The high-pain group included both those with persistent pain across the 8-day period (38% of patients in the highpain group had pain scores of Z3 all 8 assessments), as well as those with extreme pain on several days or more. The mean pain scores for each of the 8 days of the study by pain group are shown in Figure 1. The contrast between these groups is striking, given the lowest mean for the highpain group is greater than the highest mean for the low-pain group; this provides justification for dividing the groups in this way.
Nausea Longitudinal measurements of nausea were evaluated once daily from DOS through the seventh postsurgical day; each measurement was coded on an 11-point Likert scale of 0 = “None” to 10 = “Worst.”
Data Analysis Descriptive analysis, including means and SDs or frequency distributions, was done to summarize all study variables. Two-group comparisons of study variables by binary pain group indicator (high vs. low) were accomplished using regression models, including linear, logistic, or multinomial, as appropriate. Each of the models included the age, sex, education, smoking status, and facility as covariates; for the comparison of these variables between pain groups, the variable being compared was omitted as a covariate. For the group comparisons of surgical procedure and surgical approach, sex was omitted as a covariate due to its association with both outcomes (ie, gynecologic procedures and the approaches most typically used for them). Linear regression was used for the pain group comparison of age and for the comparison of the square root of total morphine equivalent dose; logistic was used for sex, education, smoking status, facility, use of perioperative antiemetics, use of regional block, use of postdischarge antiemetics, use of postoperative acetaminophen; and multinomial was used for surgical procedure and surgical approach. Pearson product moment correlation was used to test for associations between pain and nausea at each assessment day. A mixed-effects repeated-measures model, estimated using the MIXED procedure in SAS, was used to evaluate longitudinal comparisons between binary pain indicator and the outcome of nausea. The fixed effects for this model included pain group (high vs. low) and time (days 0 to 7) as well as their interaction. The participants were nested in facilities to account for correlations among patients being treated at the same surgical site. The demographic and clinical variables of age, sex, education, and square root of daily Copyright
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morphine equivalent dose were included as covariates, and surgical procedure (with 4 levels) was added to the model as an additional fixed effect, as a control for differences among patients with different procedures. Surgical approach was not included because there was a statistically significant association between approach and procedure type (w2 = 297.7, P < 0.0001). Other surgery-specific indicators included as control variables were use of antiemetics during perioperative period, antiemetics during postdischarge period, use of regional block, and use of acetaminophen during postdischarge period. In addition to the main effects, covariates, and the interaction between pain group and time, the interactions of time with both surgical approach and morphine equivalent dose were included as additional control variables. Post hoc pairwise comparisons between pain groups for fixed timepoints were made using contrast statements to determine mean differences and 95% confidence intervals for these differences. All analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC); an a-level of 0.05 was used throughout.
RESULTS The mean age of the 248 participants was 52.3 (SD = 14.7); the range of age was 19 to 87. Most respondents were female (71%) and 58% had postsecondary education. Fifteen percent of participants were current smokers. The majority of participants (53%) had general, cholecystectomy, breast, ENT, or hernia repair as the surgical procedure, and 37% had conventional surgical approach. The mean morphine equivalent dose (based on untransformed data) was 55.0 mg (SD = 122.0) and the median dose was 17.5 mg. The interquartile range was 2.5 to 60.0 mg, and the full range of morphine equivalent doses was from 0.0 to 1360.0 mg. Sixtytwo percent of the patients in this study received some type of regional block before or during surgery. The analgesics taken postdischarge included hydrocodone (35%), oxycodone (45%), and acetaminophen alone (61%); no other analgesics were recorded as used by patients at home. The total is >100% as patients may have used different pain relief strategies on different days. Overall, only 15% of patients used an antiemetic after discharge home, including promethazine (13%), and diphenhydramine, dexamethasone, or ondansetron (< 1% for each drug). As shown in Table 1, there were significant differences between 2 pain groups in age, surgical procedures, morphine equivalent dose, and postoperative acetaminophen use, controlling for demographic variables, smoking status, and facility. Respondents in the high-pain group were younger compared with those in the low-pain group (P = 0.002). More than half of those in the knee arthroscopy, orthopedic, or upper extremity surgical procedure group were in the high-pain group (55%), compared with smaller percentages of patients in this pain group for general procedures (44%), D&C/gynecologic (13%) or cystoscopy/prostate (8%; P = 0.001 for the pain group comparison). Respondents in the high-pain group had higher transformed mean morphine equivalent dosage summed over all the time periods (P < 0.001). Finally, those in the high-pain group were more likely to use acetaminophen one or more times during the postoperative period (73%) compared with the low-pain group (53%; P = 0.007 for the group comparison). The pain group comparisons of sex, education, and smoking status, facility, surgical approach, and antiemetic use both during
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TABLE 1. Pain Group Comparisons of Demographic and Clinical Characteristics, Controlling for Age, Sex, Education, Smoking Status, and Facility* (N = 248)
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TABLE 2. Significance of Covariates and Main and Interaction Effects in the Mixed-Effects Repeated-Measures Model With Daily Nausea Score as Outcome (N = 248)
Pain Groups (n [%]) Variables
High Pain (n = 97)
Low Pain (n = 151)
Age Mean (SD) 48.37 (15.24) 54.83 (13.80) Sex Male 31 (32.0) 40 (26.5) Female 66 (68.0) 111 (73.5) Education HS or below 38 (40.0) 58 (39.7) Postsecondary 57 (60.0) 88 (60.3) Smoking status Nonsmoker 79 (81.4) 132 (87.4) Smoker 18 (18.6) 19 (12.6) Facility Facility 1 28 (28.9) 27 (17.9) Facility 2 69 (71.1) 124 (82.1) Surgical procedure Generalw 58 (59.8) 74 (49.0) D&C/GYNz 6 (6.2) 39 (25.8) Knee/ortho/upper 32 (33.0) 26 (17.2) Cystoscopy/prostate 1 (1.0) 12 (8.0) Surgical approach Conventional 35 (36.1) 56 (37.1) Arthroscopic 29 (29.9) 20 (13.3) Endoscopic 3 (3.1) 37 (24.5) Laparoscopic 30 (30.9) 38 (25.2) Square root of cumulative morphine equivalent dosage (including all 8 d) Mean (SD) 7.84 (6.17) 3.68 (3.67) Perioperative antiemetic use Yes 85 (87.6) 130 (86.1) No 12 (12.4) 21 (13.9) Regional block during surgery Yes 62 (63.9) 92 (60.9) No 35 (36.1) 59 (39.1) Postdischarge antiemetic use Yes 21 (21.7) 16 (10.6) No 76 (78.3) 135 (89.4) Postdischarge acetaminophen use Yes 71 (73.2) 80 (53.0) No 26 (26.8) 71 (47.0) Cumulative pain score (including all 8 d) Mean (SD) 40.57 (13.06) 10.83 (7.07)
Variables
P 0.002 0.14 0.50 0.35 0.34 0.001
Age Female Postsecondary education Smoker Surgical procedure Daily morphine equivalent dose Perioperative antiemetic use Regional block used during surgery Postdischarge antiemetic use Postdischarge acetaminophen use Pain group Time (d) Pain grouptime Surgical type time Morphine equivalent dose time
5.4 2.8 < 0.1 2.8 < 0.1 2.0 0.1 3.3
(1) (1) (1) (1) (3) (1) (1) (1)
24.6 < 0.1 14.2 5.9 2.5 1.3 2.2
(1) (1) (1) (7) (7) (21) (7)
P 0.020 0.095 0.94 0.093 0.98 0.15 0.74 0.068 < 0.001 0.91 < 0.001 < 0.001 0.014 0.20 0.029
*Effects significant at the alpha level of 0.05 are bolded. Note: The denominator degrees of freedom = 1864 for all tests.
0.69
< 0.001 0.95 0.20 0.057 0.007 y
*Pain group comparisons made using linear, logistic, or multinomial regression, with age, gender, education, smoking status, and facility included as covariates; models with one of the covariates as the outcome did not contain that variable as a predictor. wIncludes general; cholecystectomy; breast; ear, nose, and throat (ENT); and hernia surgical procedures zD&C = dilation and curettage; GYN = gynecologic. yGroup comparison for this variable was not done as the groups were defined by cumulative pain level.
perioperative period and postdischarge, as well as use of a regional block were not statistically significant. Although not compared statistically as these scores were used to define the 2 pain groups, the mean cumulative pain score over the 8 assessments was 40.6 (SD = 13.1) in the high-pain group, relative to 10.8 (SD = 7.1) in the lowpain group (Table 1). Not surprisingly, there was a significant correlation between pain and nausea at each of the 8 assessments (DOS and each day of the 7 d after). The correlation coefficients ranged from 0.24 to 0.37 and all
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F Value (Numerator Degrees of Freedom)
were significant with P < 0.001; the mean correlation across the 8 days was 0.30, indicating a moderate association between pain and nausea. In the mixed-effects repeated-measures model (Table 2), the significant main effects and covariates were age, pain group, time, the indicators for peiroperative antiemetics and regional block, the indicators for postdischarge antiemetics and acetaminophen, and the interactions of time with each of pain group and morphine equivalent dose. Given the significant interaction effects, the main effects of pain group and time are not interpretable so post hoc analysis was not conducted for these. The mean pain group differences in nausea for each time, along with 95% confidence intervals for the mean differences, are displayed in Figure 2. This post hoc analysis of the significant time by pain group interaction includes all of the measured personal and surgery-specific covariates that may influence the relationship between pain and nausea. The largest group difference in mean nausea was at day 2 postdischarge: On average, the nausea scores for the highpain group exceeded those of the low-pain group by 1.21. By day 7 postdischarge, this mean difference had decreased
FIGURE 2. Mean differences in daily nausea scores between high-pain and low-pain groups, with 95% confidence intervals; from day of surgery to day 7 postsurgery. DOS indicates day of surgery.
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to 0.01. There was a gradual increase in the mean group difference in nausea between high-pain and low-pain groups over time, starting from DOS and continuing through day 2 postdischarge; this was followed by a gradual decrease in the discrepancy in nausea levels between the 2 groups, starting with day 3. As indicated by the limits of the confidence intervals for the mean difference, the high-pain group significantly exceeded the low-pain group in average nausea on DOS and on days 1 to 5 following discharge. The group differences on days 6 and 7 were not significant.
DISCUSSION The main finding of this study was that patients with high pain reported a greater degree of nausea on DOS and on each of the first 6 days postsurgery even when controlling for differences in age, sex, education, morphine equivalent dose, surgical approach, use of a regional block, use of antiemetics preoperatively and postdischarge, and postdischarge use of acetaminophen. The mean nausea scores of the high-pain group did not decrease to the level of those in the low-pain group until postsurgery day 6. Similar to other studies, we found that pain was significant for nearly 40% of the sample during the week following ambulatory surgery. McGrath et al11 determined that 30% of ambulatory surgery patients have moderate to severe pain after 24 hours. Others have determined that moderate to severe pain (Z4 on a scale of 0 to 10) is experienced by many patients after 48 hours,23 up to 4 days,6 4 weeks,29 and even up to 3 months.8 In a descriptive study of incidence and severity of symptoms after ambulatory surgery, pain was the most frequent symptom, often at the moderate to severe level.7,30 In this study, patients who were younger or who had an orthopedic procedure were more likely to experience high pain than the patients who had were older or had a nonorthopedic procedure, controlling for patient characteristics. Past studies have found that patients who had severe pain were significantly younger than those without it.31–33 Other researchers have also found that patients undergoing orthopedic surgery related higher pain scores. Orthopedic patients have reported more pain and nausea at 72 hours than at any other earlier time period and required a continued need for nursing contact and support.34 Chung et al31 found that orthopedic patients had more severe pain than general surgery patients and that shoulder surgery was the most painful orthopedic surgery. McGrath et al11 found that 4 of the 7 most painful surgeries in the ambulatory surgery setting were orthopedic surgeries: shoulder, elbow/hand, ankle, and knee. Watt-Watson et al26 found that patients who had received shoulder surgeries had the most pain for up to a week. Gramke et al6 also found that orthopedic surgeries were one of the most painful procedures during the first 48 hours of recovery after ambulatory surgery. Controlling for demographics and smoking status, we found an association between cumulative consumption of opioids over the 8-day period (ie, dose in morphine equivalents), and pain level, with greater doses among patients in the high-pain group. This was the rationale for including daily morphine equivalent in the longitudinal analysis; we wanted to assess the relationship between pain and nausea controlling for differences in amount of opioid used. Interestingly, we did not find a relationship between smoking status and postoperative pain although previous studies have found that postoperative analgesic Copyright
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requirements tend to be higher for smokers than nonsmokers.35 We know that smokers deprived of nicotine typically require a greater amount of opiates in the first 48 hours36 and consumption of fentanyl tends to be higher for second-hand smokers than nonsmokers, but less than smokers.37 It is possible that our lack of association between smoking status and postoperative pain group was because of the small number of smokers in the study. There was a moderate correlation between daily pain and nausea scores starting with DOS and continuing through the week following surgery. This positive association was relatively consistent over the entire 8-day period. Andersen and Krohg21 determined that complete pain relief without relief of nausea is difficult as early as 1976; only 10% of patients complained of nausea without also complaining of pain. Chia et al22 determined that postoperative pain was an associative risk factor of emesis in female patients. When attempting to develop a better model to predict the patient’s risk for PONV, Sarin et al38 found that postoperative opioids were not associated with increased risk of PONV, but the level of postoperative pain was correlated with that risk. Other experts have theorized that postoperative pain and nausea are related, but it has been difficult to determine whether postoperative pain or postoperative opioids was the cause of increased nausea.38,39 The primary finding of this study was that those with higher pain scores (ie, members of the high-pain group) had significantly more nausea starting on DOS and this continued each day until the sixth day after surgery, compared with patients who had lower pain scores. This relationship was assessed with a variety of personal and surgery-related variables included in the longitudinal model as covariates. Pain and nausea are the most frequently reported symptoms after surgery.23,40 When asked which symptoms they would most like avoid, patients chose avoidance of postoperative pain and nausea as 2 of the top 3 priorities.41 Pain and nausea were also the top 2 choices when a panel of anesthesiologists was asked which anesthesia outcome was most important to avoid.24 Patients who experienced nausea and vomiting in the past were willing to pay US$73 and US$100 to prevent the symptoms in the future. It is clear that some patients continue to suffer with pain and nausea at home for at least a week after surgery.4 The findings of this study underscore the importance of pain management following ambulatory surgery. By promoting pain management, we can better assure that the patient has a successful recovery. Rosen et al8 found that pain level at 48 hours predicts a return to normal activity at 7 days. Patient satisfaction with the perioperative experience is correlated negatively to pain and nausea.23 Further research is needed to identify pain management regimens that include pharmaceutical as well as nonpharmacologic methods of pain control. It would seem that better pain control would result in less nausea experienced by the patient; however, we do not know whether a more personalized pain management regimen would have made a difference in the present study or whether a patient education program that focused on pain management would have made an impact. However, it is likely that appropriate management of pain can contribute to a lower incidence of both pain and nausea. It has been noted that some patients do not take their opioids at home after ambulatory surgery because of the belief that the medication contributed to the nausea they were experiencing.42 Patient education could correct inaccurate beliefs about the use of analgesics and contribute to better pain management.43 There has been
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limited research conducted to capture patient experiences at home.44 This study gives us a glimpse of the pain and nausea trajectories experienced by patients after ambulatory surgery. There are several limitations to this study. This was an observational study; patients were not randomized to standardized anesthesia regimen or for type of surgery. Degree of preoperative pain was not assessed in our study and may have contributed to postoperative pain perception and scores. Future research in this area will be enhanced by controlling for preoperative pain scores. All postdischarge medication data were collected using self-report assessments of actual use; medication adherence using an objective tracking system (such as Medication Event Monitoring System) was not assessed. In addition, we did not measure patient perceptions and beliefs on use of pain medications. Finally, although we did track the use of antiemetics during the perioperative period, and postdischarge use of both antiemetics and acetaminophen, we did not compile these by accumulated daily dose. Future studies will benefit from having a more detailed summary of the links between the use of analgesics and antiemetics by dose. Another aspect for further study will be the relationship between prescribed use and adherence, and how this relates to assessed pain and nausea.
CONCLUSIONS This study determined several personal and surgical factors that are related to pain level, including age, surgical procedure total morphine equivalent, and postdischarge use of antiemetics. Patients with high pain (more severe pain during the postoperative period) reported a greater degree of nausea on DOS and on each of the first 5 days postsurgery even when controlling for differences in age, sex, education, morphine equivalent dose and surgical approach, and other medications (antiemetics and acetaminophen) taken preoperatively and after discharge. Young patients and patients undergoing orthopedic procedures tended to have higher pain ratings, controlling for demographic variables and smoking status. With the majority of surgeries conducted in the ambulatory setting, it is imperative that we determine pain management regimens and patient education practices that will allow for a more comfortable recovery for our patients. REFERENCES 1. Cullen K, Hall M, Golosinskiy A. Ambulatory surgery in the United States, 2006. National Health Statistics Reports. Centers for Disease Control and Prevention. Hyattsville, MD. no. 11, Revised. Pp. 1-28. Available at: http://www.cdc.gov/ nchs/data/nhsr/nhsr011.pdf. Accessed November 5, 2014. 2. Russo A, Elixhauser A, Steiner C, et al. Hospital-based Ambulatory Surgery, 2007. Rockville, MD: Agency for Healthcare Research and Quality; 2010. 3. Gupta A, Wu C, Elkassabany N, et al. Does the routine prophylactic use of antiemetics affect the incidence of postdischarge nausea and vomiting following ambulatory surgery?: a systematic review of randomized controlled trials. Anesthesiology. 2003;99:488–495. 4. Lipp A, Kaliappan A. Focus on quality: managing pain and PONV in day surgery. Curr Anaesth Crit Care. 2007;18:200–2007. 5. Kavanagh T, Hu P, Minogue S. Daycase laparoscopic cholecystectomy: a prospective study of post-discharge pain, analgesic and antiemetic requirements. Ir J Med Sci. 2008; 177:111–115. 6. Gramke H, di Rijke J, van Kleefe M, et al. The prevalence of postoperative pain in a cross-sectional group of patients after day-case surgery in a university hospital. Clin J Pain. 2007;23:543–548.
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7. Mattila K, Toivonen J, Janhunen L, et al. Postdischarge symptoms after ambulatory surgery: first-week incidence, intensity, and risk factors. Anesth Analg. 2005;101:1643–1650. 8. Rosen H, Bergh I, Oden A, et al. Patients’ experiences of pain following day surgery—at 48 hours, seven days and three months. Open Nurs J. 2011;5:52–59. 9. Gudex C, Sorensen J, Clausen I. Day surgery for gynaecological laparoscopy: clinical results from an RCT. Ambul Surg. 2006;12:151–156. 10. Morales R, Esteve N, Casa I, et al. Why are ambulatory surgical patients admitted to hospital?: prospective study. Ambul Surg. 2002;9:197–205. 11. McGrath B, Elgendy H, Chung F, et al. Thirty percent of patients have moderate to severe pain 24 hr after ambulatory surgery: a survey of 5703 patients. Can J Anaesth. 2004;51:888–891. 12. Pavlin D, Chen C, Penaloza D, et al. Pain as a factor complicating recovery and discharge after ambulatory surgery. Anesth Analg. 2002;95:627–634. 13. Apfel C, Philip B, Cakmakkaya O, et al. Who is at risk for postdischarge nausea and vomiting after ambulatory surgery. Anesthesiology. 2012;117:475–486. 14. Odom-Forren J, Jalota L, Moser D, et al. Incidence and predictors of post discharge nausea and vomiting in a 7 day population. J Clin Anesth. 2013;25:551–559. 15. Wu C, Berenholtz S, Pronovost P, et al. Systematic review and analysis of postdischarge symptoms after outpatient surgery. Anesthesiology. 2002;96:994–1003. 16. Candiotti K, Kovac A, Melson T, et al. Palonosetron 04-06 Study Group. A randomized, double-blind study to evaluate the efficacy and safety of three different doses of palonosetron versus placebo for preventing postoperative nausea and vomiting. Anesth Analg. 2008;107:445–451. 17. Kapur P. The big “little problem”. Anesth Analg. 1991;73:243–245. 18. Odom-Forren J, Fetzer S, Moser D. Evidence-based interventions for post discharge nausea and vomiting: a review of the literature. J Perianesth Nurs. 2006;21:411–430. 19. White P, O’Hara J, Roberson C, et al. The impact of current antiemetic practices on patient outcomes: a prospective study on high-risk patients. Anesth Analg. 2008;107:452–458. 20. Pan PH, Lee SC, Harris LC. Antiemetic prophylaxis for postdischarge nausea and vomiting and impact on functional quality of living during recovery in patients with high emetic risks: a prospective, randomized, double-blind comparison of two prophylactic antiemetic regimens. Anesth Analg. 2008;107:429–438. 21. Anderson R, Krohg K. Pain as a major cause of postoperative nausea. Can Anaesth Soc J. 1976;23:366–369. 22. Chia Y, Kuo M, Liu K, et al. Does postoperative pain induce emesis? Clin J Pain. 2002;18:317–323. 23. Pavlin D, Chen C, Penaloza D, et al. A survey of pain and other symptoms that affect the recovery process after discharge from an ambulatory surgery unit. J Clin Anesth. 2004;16: 200–206. 24. Macario A, Weinger M, Carney S, et al. Which clinical anesthesia outcomes are important to avoid? The perspective of patients. Anesth Analg. 1999;89:652–658. 25. Horvath K. Postoperative recovery at home after ambulatory gynecologic laparoscopic surgery. J Perianesth Nurs. 2003; 18:324–334. 26. Watt-Watson J, Chung F, Chan V, et al. Pain management following discharge after ambulatory same-day surgery. J Nurs Manag. 2004;12:153–161. 27. Young J, O’Connell B, McGregor S. Day surgery patients’ convalescence at home: does enhanced discharge education make a difference? Nurs Health Sci. 2000;2:29–39. 28. Vieweg W, Lipps W, Fernandez A. Opioids and methadone equivalents for clinicians. Prim Care Companion J Clin Psychiatry. 2005;7:86–88. 29. Brattwall M, Warren Stomberg M, Rawal N, et al. Patients’ assessment of 4-week recovery after ambulatory surgery. Acta Anaesthesiol Scand. 2011;55:92–98. 30. Susilahti H, Suomienen T, Leino-Kilpi H. Recovery of Finnish short-stay surgery patients. Medsurg Nurs. 2004;13:236–335.
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31. Chung F, Ritchie E, Su J. Postoperative pain in ambulatory surgery. Anesth Analg. 1997;85:808–816. 32. Marco C, Nagel J, Klink E, et al. Factors associated with selfreported pain scores among ED patients. Am J Emerg Med. 2012;30:331–337. 33. Yellen E, Davis G. Patient satisfaction in ambulatory surgery. AORN J. 2001;74:483–498. 34. Flanagan J, Jones D. High-frequency nursing diagnoses following same-day knee arthroscopy. Int J Nurs Terminol Classif. 2009;20:89–95. 35. Shi Y, Weingarten T, Mantilla C, et al. Smoking and pain: pathophysiology and clinical implications. Anesthesiology. 2010; 113:977–992. 36. Creekmore F, Lugo R, Weiland K. Postoperative opiate analgesia requirements of smokers and nonsmokers. Ann Pharmacother. 2004;38:949–953. 37. Aydogan M, Ozturk E, Erdogan M, et al. The effects of secondhand smoke on postoperative pain and fentanyl consumption. J Anesth. 2013;27:569–574.
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38. Sarin P, Urman R, Ohno-Machado L. An improved model for predicting postoperative nausea and vomiting in ambulatory surgery patients using physician-modifiable risk factors. J Am Med Inform Assoc. 2012;19:995–1002. 39. Gan TJ. Risk factors for postoperative nausea and vomiting. Anesth Analg. 2006;102:1884–1898. 40. Rosen H, Clabo L, Martensson L. Symptoms following day surgery: a review of the literature. J Adv Periop Care. 2009;4: 7–18. 41. Jenkins K, Grady D, Wong J, et al. Post-operative recovery: day surgery patients’ preferences. Br J Anaesth. 2001;86: 272–274. 42. Fetzer S, Hand M, Bouchard P, et al. Self-care activities for postdischarge nausea and vomiting. J Perianesth Nurs. 2005;20:249–254. 43. Older C, Carr E, Layzell M. Making sense of patients’ use of analgesics following day case surgery. J Adv Nurs. 2010;20:249–254. 44. Erkal S. Patients’ experiences at home after day case cystoscopy. J Clin Nurs. 2007;16:1118–1124.
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