Original Article Human Touch Effectively and Safely Reduces Pain in the Newborn Intensive Care Unit ---
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From the College of Nursing, Wayne State University, Detroit, Michigan. Address correspondence to Carolyn J. Herrington, PhD, RN, NNP-BC, College of Nursing, Wayne State University, Detroit, MI 48202. E-mail: ac9694@ wayne.edu Received October 12, 2011; Revised June 26, 2012; Accepted June 26, 2012. The data reported in this study are based on a doctoral dissertation completed by Carolyn J. Herrington. 1524-9042/$36.00 Ó 2014 by the American Society for Pain Management Nursing http://dx.doi.org/10.1016/ j.pmn.2012.06.007
Carolyn J. Herrington, PhD, RN, NNP-BC, and Lisa M. Chiodo, PhD
ABSTRACT:
This was a feasibility pilot study to evaluate the efficacy of the nonpharmacologic pain management technique of gentle human touch (GHT) in reducing pain response to heel stick in premature infants in the neonatal intensive care unit (NICU). Eleven premature infants ranging from 27 to 34 weeks’ gestational age, in a level III NICU in a teaching hospital, were recruited and randomized to order of treatment in this repeated-measures crossover-design experiment. Containment with GHT during heel stick was compared with traditional nursery care (side lying and ‘‘nested’’ in an incubator). Heart rate, respiratory rate, oxygen saturation, and cry were measured continuously beginning at baseline and continuing through heel warming, heel stick, and recovery following the heel stick. Infants who did not receive GHT had decreased respiration, increased heart rate, and increased cry time during the heel stick. In contrast, infants who received GHT did not have decreased respirations, elevated heart rates, or increased cry time during the heel stick. No significant differences were noted in oxygen saturation in either group. GHT is a simple nonpharmacologic therapy that can be used by nurses and families to reduce pain of heel stick in premature infants in the NICU. Ó 2014 by the American Society for Pain Management Nursing Premature infants between 27 and 31 weeks’ gestational age (GA) average more than 100 painful procedures in the first 2 weeks of life (Stevens, Johnston, Franck, Petryshen, Jack, & Foster, 1999). Fifty-six percent of these painful procedures are heel sticks necessary for blood sampling (Barker & Rutter, 1995.) The cumulative effect of repetitive exposure to minor procedural pain such as heel stick is thought to contribute to the significant delays and abnormalities in the neurobehavioral development of premature infants (Grunau 2002; Hack, Klein, & Taylor, 1995; Morison, Holsti, Grunau, Whitfield, Oberlander, Chan, & Williams, 2003). Effective pain relief may reduce the severity of these neurobehavioral delays, but strategies for effective pain management of these minor but frequent procedures have only recently begun to be investigated. International guidelines have mandated the assessment and treatment of pain in infants since the late 1980s (American Academy of Pediatrics Pain Management Nursing, Vol 15, No 1 (March), 2014: pp 107-115
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Committee on Fetus and Newborn, 2000; Anand, Aranda, Berde, Buckman, Capparelli, Carlo, . Walco, 2006) however, recent studies note that minor procedural pain is treated no more than 5% of the time (Hall & Anand, 2005a). Two issues complicate the treatment of minor procedural pain such as heel stick: 1) challenges in adequately identifying minor but acute pain across neonates of varying gestational ages; and 2) limited knowledge about the efficacy of available nonpharmacologic and pharmacologic interventions. The purpose of the present study was to evaluate the efficacy of the nonpharmacologic pain management technique of gentle human touch (GHT) in reducing pain response to heel stick in premature infants in the neonatal intensive care unit (NICU).
BACKGROUND Nearly 13% of all pregnancies result in premature birth (infants born before 37 weeks’ completed gestation) every year in the U.S. (Martin, Hamilton, Sutton, Ventura, Mathews, & Osterman, 2010). It is estimated that 50%–70% of infants born prematurely develop neurobehavioral deficits/delays that are often undiagnosed until preschool and early school age. These deficits/delays include an increased incidence of attention deficit disorder, anxiety and stress disorders, hypervigilance, exaggerated startle response, and altered biobehavioral response to pain (Hall & Anand, 2005b; Khurana, Hall, & Anand, 2005; Pickler, McGrath, Reyna, McCain, Lewis, Cone, Wetzel, & Best, 2010). Although multiple mechanisms affect overall neurobehavioral development in these infants, increased scientific attention has focused on the detrimental effects of minor repetitive pain exposure in the newborn intensive care unit (NICU) (Fitzgerald & Walker, 2009; Grunau, 2002; Hack, Klein, & Taylor, 1995). Changes in cortisol response to novelty have been identified in former premature infants by Grunau et al. at 8 months of age (Grunau, Weinburg, & Whitfield, 2004). These changes are theorized to be related to the cumulative effect of the multiple stressors experienced by premature infants during their NICU hospitalization and persist even when statistically controlled for acuity of illness and exposure to opiates (Grunau, Weinburg, & Whitfield, 2004). Nursery practices designed to reduce pain from minor but repetitive exposures such as heel stick may significantly reduce some of the long-term neurobehavioral problems so prevalent in infants born prematurely. Nurses need effective nonpharmacologic treatments to reduce the pain from heel sticks in this medically fragile population.
Current pain assessment tools lack the sensitivity required to quickly quantify pain response in the premature infant across all GAs, levels of illness, and pain procedures. Owing to the brief nature of the infant’s pain response to procedures such as heel stick, the ability to accurately rate pain level is particularly challenging. Gestational age, acuity of illness, postnatal age, and previous exposure to painful events complicate the challenge of pain recognition and management (Evans, McCartney, Lawhon, & Galloway, 2005; Stevens & Franck, 1995). Research evaluating the efficacy of therapies for reducing pain response to heel stick has focused on two primary approaches: 1) the effect of sucrose, formula, or breast milk combined with nonnutritive suck; and 2) touch therapies focusing on gentle containment of the infant. Using Touch to Reduce Minor Pain The use of touch containment to reduce pain response has been associated with reduction in pain response for heel stick and other minor procedures, such as endotracheal suctioning. Reduction in pain has been achieved through swaddling, skin-to-skin contact with parents (kangaroo care [KC]), as well as gentle infant flexion and containment with human hands (GHT or facilitated tuck); however, the measure for ‘‘pain’’ varies across studies (Axelin, Salantera, & Lehtonen 2006; Corff, Seideman, Venkataraman, Lutes, & Yates, 1995; Harrison, Olivet, Cunningham, Bodin, & Hicks, 1996; Ward-Larson, Horn, & Gosnell, 2004). Pain relief during KC is greater than that observed with swaddling (Johnston, Stevens, Pinelli, Gibbons, Filion, Jack, Steele, Boyer, & Veilleux, 2003), but the use of KC for each painful procedure in the NICU is not feasible. Gentle human touch can be easily provided for many minor but painful procedures regardless of the acuity of illness of the infant (Corff et al., 1995; Harrison, Olivet, Cunningham, Bodin, & Hicks, 1996; Huang, Tung, Kuo, & Chang, 2004). Study Aim The present study was designed to test the efficacy of GHT in reducing pain response in premature infants undergoing heel stick for medically indicated blood sampling compared with standard nursery care of positioning with nonhuman confinement using ‘‘blanket nesting.’’
METHODS Design, Sample, and Recruitment Study Design. This was an experimental pilot feasibility study using a repeated-measures crossover
Human Touch in the NICU
study design. Pain response was measured around two medically indicated heel sticks for blood sampling. Each infant received one heel stick with GHT intervention and one heel stick without GHT. Infants served as their own controls with random assignment to order of treatment (GHT vs. no GHT) in blocks of four to maximize study power. A minimum 24-hour washout period between treatment groups was used to reduce the risk of carry-over effect. This withinsubject design tested the null hypothesis that infant outcome measures (heart rate [HR], respiratory rate [RR], and oxygen saturation [SaO2], and cry time) would not change across the four different testing phases (baseline, heel warm, heel stick, and recovery). Sample. Sample size was determined using feasibility considerations of the number of premature infants treated in the unit where the study was conducted. The study was powered to detect an effect size of $0.70 using a two-tailed matched test design with a of .05, considering a ‘‘large effect’’ in Cohen’s classification (Cohen, 1988). Participant enrollment was limited to relatively stable infants born from 27 to 34 weeks’ GA born to English-speaking parents. For the purpose of this study, ‘‘relatively stable’’ was defined as infants who were hemodynamically stable, not requiring blood pressure support medications, with mild to moderate respiratory distress, who did not require increasing levels of support during the period of data collection. Infants receiving ventilator assistance by nasal-pharyngeal continuous positive airway pressure (NPCPAP) or nasal cannula were eligible for enrollment. Infants intubated at the time of data collection, infants with documented grade III or IV intraventricular hemorrhage, infants with known or suspected congenital anomalies, infants with known or suspected prenatal exposure to pain medications, infants with deteriorating clinical status, and infants who had surgical procedures were excluded. Human Subjects. The study protocol was approved by the human subjects review boards at Wayne State University and Sparrow Hospital. Parents were approached by the first author, who explained the study protocol. Only infants who met the eligibility criteria and whose parents provided written consent were enrolled in the study. Measures Demographic variables included birth weight, length, occipital-frontal head circumference, GA at birth, 1minute and 5-minute Apgar scores, age in hours at time of sample collections, gender, ethnicity, a proxy of severity of illness score, prenatal exposure to
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steroids, and number of previous pain exposures (limited to intramuscular injections, endotracheal intubations, intravenous or intra-arterial cannulation, and heel stick). The severity of illness score was calculated using the Neonatal Therapeutic Intervention Scoring System (NTISS) from information contained in the infants’ medical record for the 24-hour period immediately preceding each sampling period (Gray, Richardson, McCormick, Workman-Daniels, & Goldman, 1992). Age in hours was calculated from the time of birth to the time of baseline data collection for each infant, rounded to the nearest half-hour using standard mathematical rules (when age in hours included 1–30 minutes, the age was rounded down to the last full hour of age; when age in hours included 31–59 minutes, the age was rounded to the next full hour of age). Physiologic variables were HR, RR, and SaO2. The biobehavioral variable was audible cry. Data Collection. Data collection was conducted during the NICU’s routine a.m. sampling period (between 1:00 a.m. and 5:00 a.m.) and was coordinated with routine care procedures. Infants were left undisturbed for a minimum of 60 minutes before the heel stick procedure. All physiologic data (HR, RR, and SaO2) were continuously recorded and electronically entered into the study computer at 5-second intervals with the use of the Bedmaster-EX Data Acquisition Systems (Excel Medical Electronics, Jupiter, Florida). Cry was audiorecorded. Intervention Gentle human touch was the intervention tested in the study. The first author administered the intervention (GHT or no GHT) for all infants. GHT was accomplished by placing the infant in a side-lying position and gently flexing the infant into a tucked position similar to the flexed fetal position infants naturally assume in the womb as they near term gestation. This flexed position provides a stabilizing and comforting effect on the premature infant (Als, 1986). GHT is provided by cupping one hand around the infant’s head while cupping the other hand around the infant’s bottom. This position allowed the infant to move but limited extension and flailing of the extremities (Fig. 1). In the control phase, the infants were also placed in side-lying position and supported with blanket rolls to create a ‘‘nest confinement’’ which is the standard of care in the NICU where this study was conducted. To control for the potential that the presence of another person might be comforting to the infant, hands were placed inside the incubator during the non-GHT heel sticks. Hands were positioned together, palm to dorsal surface, right
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FIGURE 1. - Photo of a 28-week-gestational-age infant receiving gentle human touch. No blanket is used in this picture, to allow the touch therapy to be seen.
hand over left and placed next to, but not in contact with the infant. Infant Preparation. Infants’ heels were prewarmed for 2 minutes before the heel stick with the use of an activated sodium thiosulfate Infant Heel Warmer (Cardinal Health, McGraw Park, Illiinois). The GHT administrator prewarmed her hands simultaneously with a second heel warmer to minimize the risk of cold stress reaction during both the GHT and no GHT interventions. Blankets were prewarmed to 120 F (Olympic blanket warmer; Olympic Medical, Seattle, Washington) and were loosely draped over all infants in both groups before the heel stick procedures (Fig. 2). The prewarmed blankets were positioned to cover the hands of the GHT administrator completely, before
FIGURE 2. - Prewarmed blanket positioned over infant during heel stick.
the arrival of the phlebotomist at the bedside, so that the phlebotomist was unaware of the experimental assignment of the infant. This design eliminated the potential that the presence of another person during the GHT treatment, but not during no GHT, might affect the phlebotomist’s technique during heel sampling process. Heel Stick. The phlebotomist cleansed the infant’s heel with a 70% alcohol wipe. The infant’s skin airdried for 30 seconds before heel stick. The heel stick was performed with a BD Quikheel Preemie Lancet (BD, Franklin Lakes, New Jersey). Following the heel stick, the phlebotomist squeezed the heel with a gloved hand to facilitate blood flow for the sample collection. Length of sample collection time was recorded.
RESULTS Data Analysis Descriptive statistics were used to analyze the demographic data and evaluate distributions, measures of central tendency, and outcome variable variability (HR, RR, SaO2, and cry). In SPSS (version 20), repeated-measures analysis of variance was used to analyze the effects of intervention versus no intervention. Paired t tests were used to analyze difference in audible cry. This within-subject design tested the null hypothesis that infant outcome measures (HR, RR, SaO2, and cry time) would not change across the testing phases (baseline, heel warm, heel stick, and recovery). The heel stick procedure was divided into four phases for comparison: baseline, heel warm, heel stick, and recovery. A multivariate comparison of outcome variable values was assessed with the use of the general linear model (GLM). In addition, univariate paired t tests were used to assess values between the no-touch and touch condition for specific phases. Given the directional hypothesis that there would be significant change in the HR, RR, SaO2, and cry time values for the no-touch condition (increased HR, increased RR, decreased SaO2, and increased cry time), but there would be no significant change in the outcome variables in the touch condition, one-tail tests were used in the analyses. Sample Description A total of 123 infants were admitted to the NICU during the study period. Of these 123 infants, 39 infants (31.7%) met the gestational age criteria. Twenty-one (53.8%) of those 39 infants were enrolled (Fig. 3). Of the 21 infants who were enrolled, one infant was withdrawn due to deterioration in clinical status, six infants
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Human Touch in the NICU
FIGURE 3.
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Description of subject enrollment.
were discharged home before the second data collection, and data from three infants was unusable due to issues with the monitoring devices, leaving 11 infants (52% of those enrolled) who completed the study. Physiologic data for the baseline period were not available for two of the infants owing to technical difficulties, but baseline measurements did not differ significantly between groups, so data for all 11 infants were included in the final analysis. Infant Characteristics. Mean infant GA was 31 weeks (SD 1.7). Mean birth weight was 1.9 kg (SD 0.4). Nine of the infants were delivered by cesarean section, and two vaginally. Six infants were male and five female. Mean birth weight was 1.889 kg (SD 0.37). Mean Neonatal Therapeutic Intervention Scoring System (NTISS) score on sampling day 1 was 10.88 and mean NTISS score on sampling day 2 was 8.55. Respiratory distress and prematurity were the primary admitting diagnoses for all of the infants. Forty-five percent of the infants required respiratory support on day 1 of the sampling procedure. All infants were evaluated for sepsis and treatment with antibiotics was initiated. Eight (73%) of the infants had antibiotic therapy discontinued by 72 hours of age; three (27%) of the infants had antibiotic therapy for 7 days. Mean age for infants on day 1 of the sampling procedure was 97 hours (SD 21.34). Mean age on day 2 of the sampling procedure was 166.36 hours (SD 103.56). The mean number of previous heel sticks or intravenous insertion attempts before the first
sampling was 18.45 (SD 5.20), and the mean number of previous heel sticks or intravenous insertion attempts between sampling days 1 and 2 was 2.73 (SD 2.14). All but one of the infants had the second samples taken within 48 hours of the first sampling. One infant’s second sampling occurred 1 week after the first sampling, because there were no prior lab samples requested by the medical team for that infant. Apgar scores for the infants were similar, with a mean 6.2 (SD 1.9) at 1 minute and 7.8 (SD 1.0) for 5 minutes. See Table 1 for demographic description of the sample.
TABLE 1. Sample Characteristics Mean or % SD Min Max Gestational age (wk) Birth weight (kg) Gender (% male) Age at first sampling (h) Age at second sampling (h) Apgar 1 min 5 min NTISS Day 1 Day 2 Respiratory Support (% yes) Antibiotics (% >72 h)
31.0 1.9 54.5 97.0 166.4
1.7 0.4 –– 68.4 103.6
6.2 7.8
1.9 1.0
10.2 8.6 45.0 27.0
27 33 1 3 –– –– 75 146 93 458 2 6
9 9
3.1 6 2.4 5 –– –– –– ––
15 12 –– ––
NTISS ¼ neonatal therapeutic intervention scoring system.
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TABLE 2. Age and NTISS Score Across Intervention Conditions GHT
Age (h)* NTISS*
No GHT
Mean
SD
Mean
SD
120.64 9.18
47.91 2.75
142.81 9.55
106.14 2.08
*No significant difference between groups.
In addition to the above infant data, age in hours at sampling and NTISS score were obtained and compared across intervention phases. Infant’s age at the time of assessment and NTISS scores were not significantly different between conditions (Table 2). Neonatal Outcome Results Multivariate Analyses. GLM analyses identified significant differences across phases for HR, RR, and cry time between the intervention groups (HR: Pillai trace F ¼ 6.82; p ¼ .012; RR: Pillai trace F ¼ 5.70; p ¼ .017; cry time: Pillai trace F ¼ 4.14; p ¼ .033). No significant multivariate results were identified for SaO2 when evaluating differences across phases between the touch conditions (Table 3). Univariate Analysis. Univariate analyses were performed on all variables identified as significant or marginally significant in the multivariate analyses. Univariate analysis of HR within the no-touch group revealed significant differences between the baseline and heel stick phases (t ¼ 2.940; p ¼ .010) as well as between the heel warming and heel stick phases
(t ¼ 4.238; p ¼ .001). In both multivariate and univariate analyses, infant heart rates were significantly elevated in the heel stick condition. In addition, there was a significant difference in infants’ HR between the heel warming and recovery phases (t ¼ 2.103; p ¼ .031) as well as between the heel stick and recovery phases (t ¼ 1.891; p ¼ .044). In these analyses, HR during the recovery phase was higher than in the heel warming phase but lower than in the heel stick phase. There was no difference between the baseline and recovery phases. Univariate analysis of RR data within the no-touch condition also identified significant difference between phases. RR was significantly reduced in the heel stick condition compared with both baseline (t ¼ 3.374; p ¼ .005) and heel warming (t ¼ 4.079; p ¼ .001). RR at heel stick was also significantly reduced compared with the recovery phase (t ¼ 2.212; p ¼ .026). In addition, there was a marginally significant difference between RR rate in the baseline and heel warming phases (t ¼ 1.843; p ¼ .052); infants’ RR was slightly elevated in the heel warming phase compared with baseline. Differences between phases were also examined for RR in the touch condition. In these analyses, RR was higher in the recovery phase than all three other phases (baseline: t ¼ 2.543; p ¼ .016; heel warming: t ¼ 2.010; p ¼ .032; heel stick: t ¼ 2.800; p ¼ .010). There was no significant difference in RR rates in the touch condition between baseline and heel stick or between heel warming and heel stick. Analyses of the cry data revealed that five of the infants cried during the GHT condition and 9 cried in the non-GHT condition. Paired-sample t tests identified significant difference between phases in the no-touch
TABLE 3. Pain Response (Mean Values) by Phase and Touch Group GHT
No GHT
Heel Baseline Warming Heel Stick Recovery RR§{ HRj SPO2 Cry time**
50.04 155.40 95.84 0.07
50.89 155.72 95.71 0.08
47.72 156.11 94.30 0.24
57.92 153.81 93.57 0.17
F‡ 2.98† 0.46 2.13 1.21
Heel Baseline Warming Heel Stick Recovery 50.33 154.91 96.72 0.13
55.41 152.52 96.90 0.08
37.61 169.41 96.56 0.60
*p < .05. † p < .10. ‡ Pillai trace F. § Respiration rate: touch: baseline < recovery; heel warming < recovery; heel stick < recovery. { Respiration rate: no touch: baseline > heel stick; heel warming > heel stick; heel stick < recovery. j Heart rate: no touch: baseline < heel stick; heel warming < heel stick; heel warming < recovery; heel stick > recovery. **Cry time: no touch: baseline < heel stick; heel warming < heel stick; heel warming < recovery; heel stick > recovery.
51.99 160.80 96.16 0.27
F‡ 5.70* 6.82* 1.41 4.14*
Human Touch in the NICU
condition for length of cry time. Infants cried more in the heel stick condition compared with all other phases (baseline: t ¼ 2.940; p ¼ .010; heel warming: t ¼ 4.238; p ¼ .001; recovery: t ¼ 1.891; p ¼ .044). Cry time was also higher in the recovery period compared with the heel warming phase (t ¼ 2.103; p ¼ .031). To further explore differences in cry time, length of cry in the GHT condition was compared with length of cry in the non-GHT condition in the heel stick phase. Results showed significantly more cry time during the non-GHT condition than in the GHT condition (t ¼ 2.099; p ¼ .031).
DISCUSSION The data reported here provide evidence of the ability of GHT to reduce pain response in premature infants undergoing heel stick for medically indicated blood sampling compared with standard nursery care of positioning with nonhuman confinement using ‘‘blanket nesting.’’ Infants in the GHT condition did not show reduced RR, elevated HR, or increased cry time in the stress condition of a heel stick. In fact, across the two conditions, cry time was significantly reduced in the GHT condition during the heel stick phase. The significant RR differences noted between groups, with RR lower during heel stick without GHT, may indicate breath-holding during the heel stick itself. No significant differences were noted between the GHT and non-GHT groups in SaO2 in response to pain of heel stick. To the authors’ knowledge, this is the first study to show reduction in HR variability, RR, and cry time in premature infants undergoing heel stick. It is possible that the use of a 5-second interval, which provided a rich base of >2,700 individual measurements used to calculate the mean measures for this study enhanced the likelihood of identifying an effect. One of the most common parameters used in pain scoring systems in the NICU is rise in HR. In this study, mean HR varied only 0.7 beats/min between baseline, heel warming, and heel stick for heel stick with GHT. The mean HR in the non-GHT group rose 14.5 beats/min between baseline and the heel stick phase, and the elevation lasted through the recovery phase. Before the design of this study, three studies were identified in the literature that examined the effects of touch on reducing pain of heel stick in premature infants (Corff et al., 1995; Johnston et al., 2003; Ludington-Hoe, Hosseini, & Torowicz, 2005). Johnston et al. (2003) compared pain response to heel stick in premature infants of 32-37 weeks’ GA between skin-to-skin position on the mother’s chest (KC) and prone positioning in
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the incubator. Total pain scores were lower at 30, 60, and 90 seconds after heel stick with KC, but there was no significant difference noted 120 seconds after heel stick. When individual components of the pain score were analyzed, there were no significant differences in HR or SaO2 between groups. The heel stick procedure was not analyzed by individual phases. Ludington-Hoe et al. (2005) also studied pain response between heel stick received during KC compared with ‘ nesting’’ in warmer. The infants in that study were premature (
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From the College of Nursing, Wayne State University, Detroit, Michigan. Address correspondence to Carolyn J. Herrington, PhD, RN, NNP-BC, College of Nursing, Wayne State University, Detroit, MI 48202. E-mail: ac9694@ wayne.edu Received October 12, 2011; Revised June 26, 2012; Accepted June 26, 2012. The data reported in this study are based on a doctoral dissertation completed by Carolyn J. Herrington. 1524-9042/$36.00 Ó 2014 by the American Society for Pain Management Nursing http://dx.doi.org/10.1016/ j.pmn.2012.06.007
Carolyn J. Herrington, PhD, RN, NNP-BC, and Lisa M. Chiodo, PhD
ABSTRACT:
This was a feasibility pilot study to evaluate the efficacy of the nonpharmacologic pain management technique of gentle human touch (GHT) in reducing pain response to heel stick in premature infants in the neonatal intensive care unit (NICU). Eleven premature infants ranging from 27 to 34 weeks’ gestational age, in a level III NICU in a teaching hospital, were recruited and randomized to order of treatment in this repeated-measures crossover-design experiment. Containment with GHT during heel stick was compared with traditional nursery care (side lying and ‘‘nested’’ in an incubator). Heart rate, respiratory rate, oxygen saturation, and cry were measured continuously beginning at baseline and continuing through heel warming, heel stick, and recovery following the heel stick. Infants who did not receive GHT had decreased respiration, increased heart rate, and increased cry time during the heel stick. In contrast, infants who received GHT did not have decreased respirations, elevated heart rates, or increased cry time during the heel stick. No significant differences were noted in oxygen saturation in either group. GHT is a simple nonpharmacologic therapy that can be used by nurses and families to reduce pain of heel stick in premature infants in the NICU. Ó 2014 by the American Society for Pain Management Nursing Premature infants between 27 and 31 weeks’ gestational age (GA) average more than 100 painful procedures in the first 2 weeks of life (Stevens, Johnston, Franck, Petryshen, Jack, & Foster, 1999). Fifty-six percent of these painful procedures are heel sticks necessary for blood sampling (Barker & Rutter, 1995.) The cumulative effect of repetitive exposure to minor procedural pain such as heel stick is thought to contribute to the significant delays and abnormalities in the neurobehavioral development of premature infants (Grunau 2002; Hack, Klein, & Taylor, 1995; Morison, Holsti, Grunau, Whitfield, Oberlander, Chan, & Williams, 2003). Effective pain relief may reduce the severity of these neurobehavioral delays, but strategies for effective pain management of these minor but frequent procedures have only recently begun to be investigated. International guidelines have mandated the assessment and treatment of pain in infants since the late 1980s (American Academy of Pediatrics Pain Management Nursing, Vol 15, No 1 (March), 2014: pp 107-115
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Committee on Fetus and Newborn, 2000; Anand, Aranda, Berde, Buckman, Capparelli, Carlo, . Walco, 2006) however, recent studies note that minor procedural pain is treated no more than 5% of the time (Hall & Anand, 2005a). Two issues complicate the treatment of minor procedural pain such as heel stick: 1) challenges in adequately identifying minor but acute pain across neonates of varying gestational ages; and 2) limited knowledge about the efficacy of available nonpharmacologic and pharmacologic interventions. The purpose of the present study was to evaluate the efficacy of the nonpharmacologic pain management technique of gentle human touch (GHT) in reducing pain response to heel stick in premature infants in the neonatal intensive care unit (NICU).
BACKGROUND Nearly 13% of all pregnancies result in premature birth (infants born before 37 weeks’ completed gestation) every year in the U.S. (Martin, Hamilton, Sutton, Ventura, Mathews, & Osterman, 2010). It is estimated that 50%–70% of infants born prematurely develop neurobehavioral deficits/delays that are often undiagnosed until preschool and early school age. These deficits/delays include an increased incidence of attention deficit disorder, anxiety and stress disorders, hypervigilance, exaggerated startle response, and altered biobehavioral response to pain (Hall & Anand, 2005b; Khurana, Hall, & Anand, 2005; Pickler, McGrath, Reyna, McCain, Lewis, Cone, Wetzel, & Best, 2010). Although multiple mechanisms affect overall neurobehavioral development in these infants, increased scientific attention has focused on the detrimental effects of minor repetitive pain exposure in the newborn intensive care unit (NICU) (Fitzgerald & Walker, 2009; Grunau, 2002; Hack, Klein, & Taylor, 1995). Changes in cortisol response to novelty have been identified in former premature infants by Grunau et al. at 8 months of age (Grunau, Weinburg, & Whitfield, 2004). These changes are theorized to be related to the cumulative effect of the multiple stressors experienced by premature infants during their NICU hospitalization and persist even when statistically controlled for acuity of illness and exposure to opiates (Grunau, Weinburg, & Whitfield, 2004). Nursery practices designed to reduce pain from minor but repetitive exposures such as heel stick may significantly reduce some of the long-term neurobehavioral problems so prevalent in infants born prematurely. Nurses need effective nonpharmacologic treatments to reduce the pain from heel sticks in this medically fragile population.
Current pain assessment tools lack the sensitivity required to quickly quantify pain response in the premature infant across all GAs, levels of illness, and pain procedures. Owing to the brief nature of the infant’s pain response to procedures such as heel stick, the ability to accurately rate pain level is particularly challenging. Gestational age, acuity of illness, postnatal age, and previous exposure to painful events complicate the challenge of pain recognition and management (Evans, McCartney, Lawhon, & Galloway, 2005; Stevens & Franck, 1995). Research evaluating the efficacy of therapies for reducing pain response to heel stick has focused on two primary approaches: 1) the effect of sucrose, formula, or breast milk combined with nonnutritive suck; and 2) touch therapies focusing on gentle containment of the infant. Using Touch to Reduce Minor Pain The use of touch containment to reduce pain response has been associated with reduction in pain response for heel stick and other minor procedures, such as endotracheal suctioning. Reduction in pain has been achieved through swaddling, skin-to-skin contact with parents (kangaroo care [KC]), as well as gentle infant flexion and containment with human hands (GHT or facilitated tuck); however, the measure for ‘‘pain’’ varies across studies (Axelin, Salantera, & Lehtonen 2006; Corff, Seideman, Venkataraman, Lutes, & Yates, 1995; Harrison, Olivet, Cunningham, Bodin, & Hicks, 1996; Ward-Larson, Horn, & Gosnell, 2004). Pain relief during KC is greater than that observed with swaddling (Johnston, Stevens, Pinelli, Gibbons, Filion, Jack, Steele, Boyer, & Veilleux, 2003), but the use of KC for each painful procedure in the NICU is not feasible. Gentle human touch can be easily provided for many minor but painful procedures regardless of the acuity of illness of the infant (Corff et al., 1995; Harrison, Olivet, Cunningham, Bodin, & Hicks, 1996; Huang, Tung, Kuo, & Chang, 2004). Study Aim The present study was designed to test the efficacy of GHT in reducing pain response in premature infants undergoing heel stick for medically indicated blood sampling compared with standard nursery care of positioning with nonhuman confinement using ‘‘blanket nesting.’’
METHODS Design, Sample, and Recruitment Study Design. This was an experimental pilot feasibility study using a repeated-measures crossover
Human Touch in the NICU
study design. Pain response was measured around two medically indicated heel sticks for blood sampling. Each infant received one heel stick with GHT intervention and one heel stick without GHT. Infants served as their own controls with random assignment to order of treatment (GHT vs. no GHT) in blocks of four to maximize study power. A minimum 24-hour washout period between treatment groups was used to reduce the risk of carry-over effect. This withinsubject design tested the null hypothesis that infant outcome measures (heart rate [HR], respiratory rate [RR], and oxygen saturation [SaO2], and cry time) would not change across the four different testing phases (baseline, heel warm, heel stick, and recovery). Sample. Sample size was determined using feasibility considerations of the number of premature infants treated in the unit where the study was conducted. The study was powered to detect an effect size of $0.70 using a two-tailed matched test design with a of .05, considering a ‘‘large effect’’ in Cohen’s classification (Cohen, 1988). Participant enrollment was limited to relatively stable infants born from 27 to 34 weeks’ GA born to English-speaking parents. For the purpose of this study, ‘‘relatively stable’’ was defined as infants who were hemodynamically stable, not requiring blood pressure support medications, with mild to moderate respiratory distress, who did not require increasing levels of support during the period of data collection. Infants receiving ventilator assistance by nasal-pharyngeal continuous positive airway pressure (NPCPAP) or nasal cannula were eligible for enrollment. Infants intubated at the time of data collection, infants with documented grade III or IV intraventricular hemorrhage, infants with known or suspected congenital anomalies, infants with known or suspected prenatal exposure to pain medications, infants with deteriorating clinical status, and infants who had surgical procedures were excluded. Human Subjects. The study protocol was approved by the human subjects review boards at Wayne State University and Sparrow Hospital. Parents were approached by the first author, who explained the study protocol. Only infants who met the eligibility criteria and whose parents provided written consent were enrolled in the study. Measures Demographic variables included birth weight, length, occipital-frontal head circumference, GA at birth, 1minute and 5-minute Apgar scores, age in hours at time of sample collections, gender, ethnicity, a proxy of severity of illness score, prenatal exposure to
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steroids, and number of previous pain exposures (limited to intramuscular injections, endotracheal intubations, intravenous or intra-arterial cannulation, and heel stick). The severity of illness score was calculated using the Neonatal Therapeutic Intervention Scoring System (NTISS) from information contained in the infants’ medical record for the 24-hour period immediately preceding each sampling period (Gray, Richardson, McCormick, Workman-Daniels, & Goldman, 1992). Age in hours was calculated from the time of birth to the time of baseline data collection for each infant, rounded to the nearest half-hour using standard mathematical rules (when age in hours included 1–30 minutes, the age was rounded down to the last full hour of age; when age in hours included 31–59 minutes, the age was rounded to the next full hour of age). Physiologic variables were HR, RR, and SaO2. The biobehavioral variable was audible cry. Data Collection. Data collection was conducted during the NICU’s routine a.m. sampling period (between 1:00 a.m. and 5:00 a.m.) and was coordinated with routine care procedures. Infants were left undisturbed for a minimum of 60 minutes before the heel stick procedure. All physiologic data (HR, RR, and SaO2) were continuously recorded and electronically entered into the study computer at 5-second intervals with the use of the Bedmaster-EX Data Acquisition Systems (Excel Medical Electronics, Jupiter, Florida). Cry was audiorecorded. Intervention Gentle human touch was the intervention tested in the study. The first author administered the intervention (GHT or no GHT) for all infants. GHT was accomplished by placing the infant in a side-lying position and gently flexing the infant into a tucked position similar to the flexed fetal position infants naturally assume in the womb as they near term gestation. This flexed position provides a stabilizing and comforting effect on the premature infant (Als, 1986). GHT is provided by cupping one hand around the infant’s head while cupping the other hand around the infant’s bottom. This position allowed the infant to move but limited extension and flailing of the extremities (Fig. 1). In the control phase, the infants were also placed in side-lying position and supported with blanket rolls to create a ‘‘nest confinement’’ which is the standard of care in the NICU where this study was conducted. To control for the potential that the presence of another person might be comforting to the infant, hands were placed inside the incubator during the non-GHT heel sticks. Hands were positioned together, palm to dorsal surface, right
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FIGURE 1. - Photo of a 28-week-gestational-age infant receiving gentle human touch. No blanket is used in this picture, to allow the touch therapy to be seen.
hand over left and placed next to, but not in contact with the infant. Infant Preparation. Infants’ heels were prewarmed for 2 minutes before the heel stick with the use of an activated sodium thiosulfate Infant Heel Warmer (Cardinal Health, McGraw Park, Illiinois). The GHT administrator prewarmed her hands simultaneously with a second heel warmer to minimize the risk of cold stress reaction during both the GHT and no GHT interventions. Blankets were prewarmed to 120 F (Olympic blanket warmer; Olympic Medical, Seattle, Washington) and were loosely draped over all infants in both groups before the heel stick procedures (Fig. 2). The prewarmed blankets were positioned to cover the hands of the GHT administrator completely, before
FIGURE 2. - Prewarmed blanket positioned over infant during heel stick.
the arrival of the phlebotomist at the bedside, so that the phlebotomist was unaware of the experimental assignment of the infant. This design eliminated the potential that the presence of another person during the GHT treatment, but not during no GHT, might affect the phlebotomist’s technique during heel sampling process. Heel Stick. The phlebotomist cleansed the infant’s heel with a 70% alcohol wipe. The infant’s skin airdried for 30 seconds before heel stick. The heel stick was performed with a BD Quikheel Preemie Lancet (BD, Franklin Lakes, New Jersey). Following the heel stick, the phlebotomist squeezed the heel with a gloved hand to facilitate blood flow for the sample collection. Length of sample collection time was recorded.
RESULTS Data Analysis Descriptive statistics were used to analyze the demographic data and evaluate distributions, measures of central tendency, and outcome variable variability (HR, RR, SaO2, and cry). In SPSS (version 20), repeated-measures analysis of variance was used to analyze the effects of intervention versus no intervention. Paired t tests were used to analyze difference in audible cry. This within-subject design tested the null hypothesis that infant outcome measures (HR, RR, SaO2, and cry time) would not change across the testing phases (baseline, heel warm, heel stick, and recovery). The heel stick procedure was divided into four phases for comparison: baseline, heel warm, heel stick, and recovery. A multivariate comparison of outcome variable values was assessed with the use of the general linear model (GLM). In addition, univariate paired t tests were used to assess values between the no-touch and touch condition for specific phases. Given the directional hypothesis that there would be significant change in the HR, RR, SaO2, and cry time values for the no-touch condition (increased HR, increased RR, decreased SaO2, and increased cry time), but there would be no significant change in the outcome variables in the touch condition, one-tail tests were used in the analyses. Sample Description A total of 123 infants were admitted to the NICU during the study period. Of these 123 infants, 39 infants (31.7%) met the gestational age criteria. Twenty-one (53.8%) of those 39 infants were enrolled (Fig. 3). Of the 21 infants who were enrolled, one infant was withdrawn due to deterioration in clinical status, six infants
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FIGURE 3.
-
Description of subject enrollment.
were discharged home before the second data collection, and data from three infants was unusable due to issues with the monitoring devices, leaving 11 infants (52% of those enrolled) who completed the study. Physiologic data for the baseline period were not available for two of the infants owing to technical difficulties, but baseline measurements did not differ significantly between groups, so data for all 11 infants were included in the final analysis. Infant Characteristics. Mean infant GA was 31 weeks (SD 1.7). Mean birth weight was 1.9 kg (SD 0.4). Nine of the infants were delivered by cesarean section, and two vaginally. Six infants were male and five female. Mean birth weight was 1.889 kg (SD 0.37). Mean Neonatal Therapeutic Intervention Scoring System (NTISS) score on sampling day 1 was 10.88 and mean NTISS score on sampling day 2 was 8.55. Respiratory distress and prematurity were the primary admitting diagnoses for all of the infants. Forty-five percent of the infants required respiratory support on day 1 of the sampling procedure. All infants were evaluated for sepsis and treatment with antibiotics was initiated. Eight (73%) of the infants had antibiotic therapy discontinued by 72 hours of age; three (27%) of the infants had antibiotic therapy for 7 days. Mean age for infants on day 1 of the sampling procedure was 97 hours (SD 21.34). Mean age on day 2 of the sampling procedure was 166.36 hours (SD 103.56). The mean number of previous heel sticks or intravenous insertion attempts before the first
sampling was 18.45 (SD 5.20), and the mean number of previous heel sticks or intravenous insertion attempts between sampling days 1 and 2 was 2.73 (SD 2.14). All but one of the infants had the second samples taken within 48 hours of the first sampling. One infant’s second sampling occurred 1 week after the first sampling, because there were no prior lab samples requested by the medical team for that infant. Apgar scores for the infants were similar, with a mean 6.2 (SD 1.9) at 1 minute and 7.8 (SD 1.0) for 5 minutes. See Table 1 for demographic description of the sample.
TABLE 1. Sample Characteristics Mean or % SD Min Max Gestational age (wk) Birth weight (kg) Gender (% male) Age at first sampling (h) Age at second sampling (h) Apgar 1 min 5 min NTISS Day 1 Day 2 Respiratory Support (% yes) Antibiotics (% >72 h)
31.0 1.9 54.5 97.0 166.4
1.7 0.4 –– 68.4 103.6
6.2 7.8
1.9 1.0
10.2 8.6 45.0 27.0
27 33 1 3 –– –– 75 146 93 458 2 6
9 9
3.1 6 2.4 5 –– –– –– ––
15 12 –– ––
NTISS ¼ neonatal therapeutic intervention scoring system.
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TABLE 2. Age and NTISS Score Across Intervention Conditions GHT
Age (h)* NTISS*
No GHT
Mean
SD
Mean
SD
120.64 9.18
47.91 2.75
142.81 9.55
106.14 2.08
*No significant difference between groups.
In addition to the above infant data, age in hours at sampling and NTISS score were obtained and compared across intervention phases. Infant’s age at the time of assessment and NTISS scores were not significantly different between conditions (Table 2). Neonatal Outcome Results Multivariate Analyses. GLM analyses identified significant differences across phases for HR, RR, and cry time between the intervention groups (HR: Pillai trace F ¼ 6.82; p ¼ .012; RR: Pillai trace F ¼ 5.70; p ¼ .017; cry time: Pillai trace F ¼ 4.14; p ¼ .033). No significant multivariate results were identified for SaO2 when evaluating differences across phases between the touch conditions (Table 3). Univariate Analysis. Univariate analyses were performed on all variables identified as significant or marginally significant in the multivariate analyses. Univariate analysis of HR within the no-touch group revealed significant differences between the baseline and heel stick phases (t ¼ 2.940; p ¼ .010) as well as between the heel warming and heel stick phases
(t ¼ 4.238; p ¼ .001). In both multivariate and univariate analyses, infant heart rates were significantly elevated in the heel stick condition. In addition, there was a significant difference in infants’ HR between the heel warming and recovery phases (t ¼ 2.103; p ¼ .031) as well as between the heel stick and recovery phases (t ¼ 1.891; p ¼ .044). In these analyses, HR during the recovery phase was higher than in the heel warming phase but lower than in the heel stick phase. There was no difference between the baseline and recovery phases. Univariate analysis of RR data within the no-touch condition also identified significant difference between phases. RR was significantly reduced in the heel stick condition compared with both baseline (t ¼ 3.374; p ¼ .005) and heel warming (t ¼ 4.079; p ¼ .001). RR at heel stick was also significantly reduced compared with the recovery phase (t ¼ 2.212; p ¼ .026). In addition, there was a marginally significant difference between RR rate in the baseline and heel warming phases (t ¼ 1.843; p ¼ .052); infants’ RR was slightly elevated in the heel warming phase compared with baseline. Differences between phases were also examined for RR in the touch condition. In these analyses, RR was higher in the recovery phase than all three other phases (baseline: t ¼ 2.543; p ¼ .016; heel warming: t ¼ 2.010; p ¼ .032; heel stick: t ¼ 2.800; p ¼ .010). There was no significant difference in RR rates in the touch condition between baseline and heel stick or between heel warming and heel stick. Analyses of the cry data revealed that five of the infants cried during the GHT condition and 9 cried in the non-GHT condition. Paired-sample t tests identified significant difference between phases in the no-touch
TABLE 3. Pain Response (Mean Values) by Phase and Touch Group GHT
No GHT
Heel Baseline Warming Heel Stick Recovery RR§{ HRj SPO2 Cry time**
50.04 155.40 95.84 0.07
50.89 155.72 95.71 0.08
47.72 156.11 94.30 0.24
57.92 153.81 93.57 0.17
F‡ 2.98† 0.46 2.13 1.21
Heel Baseline Warming Heel Stick Recovery 50.33 154.91 96.72 0.13
55.41 152.52 96.90 0.08
37.61 169.41 96.56 0.60
*p < .05. † p < .10. ‡ Pillai trace F. § Respiration rate: touch: baseline < recovery; heel warming < recovery; heel stick < recovery. { Respiration rate: no touch: baseline > heel stick; heel warming > heel stick; heel stick < recovery. j Heart rate: no touch: baseline < heel stick; heel warming < heel stick; heel warming < recovery; heel stick > recovery. **Cry time: no touch: baseline < heel stick; heel warming < heel stick; heel warming < recovery; heel stick > recovery.
51.99 160.80 96.16 0.27
F‡ 5.70* 6.82* 1.41 4.14*
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condition for length of cry time. Infants cried more in the heel stick condition compared with all other phases (baseline: t ¼ 2.940; p ¼ .010; heel warming: t ¼ 4.238; p ¼ .001; recovery: t ¼ 1.891; p ¼ .044). Cry time was also higher in the recovery period compared with the heel warming phase (t ¼ 2.103; p ¼ .031). To further explore differences in cry time, length of cry in the GHT condition was compared with length of cry in the non-GHT condition in the heel stick phase. Results showed significantly more cry time during the non-GHT condition than in the GHT condition (t ¼ 2.099; p ¼ .031).
DISCUSSION The data reported here provide evidence of the ability of GHT to reduce pain response in premature infants undergoing heel stick for medically indicated blood sampling compared with standard nursery care of positioning with nonhuman confinement using ‘‘blanket nesting.’’ Infants in the GHT condition did not show reduced RR, elevated HR, or increased cry time in the stress condition of a heel stick. In fact, across the two conditions, cry time was significantly reduced in the GHT condition during the heel stick phase. The significant RR differences noted between groups, with RR lower during heel stick without GHT, may indicate breath-holding during the heel stick itself. No significant differences were noted between the GHT and non-GHT groups in SaO2 in response to pain of heel stick. To the authors’ knowledge, this is the first study to show reduction in HR variability, RR, and cry time in premature infants undergoing heel stick. It is possible that the use of a 5-second interval, which provided a rich base of >2,700 individual measurements used to calculate the mean measures for this study enhanced the likelihood of identifying an effect. One of the most common parameters used in pain scoring systems in the NICU is rise in HR. In this study, mean HR varied only 0.7 beats/min between baseline, heel warming, and heel stick for heel stick with GHT. The mean HR in the non-GHT group rose 14.5 beats/min between baseline and the heel stick phase, and the elevation lasted through the recovery phase. Before the design of this study, three studies were identified in the literature that examined the effects of touch on reducing pain of heel stick in premature infants (Corff et al., 1995; Johnston et al., 2003; Ludington-Hoe, Hosseini, & Torowicz, 2005). Johnston et al. (2003) compared pain response to heel stick in premature infants of 32-37 weeks’ GA between skin-to-skin position on the mother’s chest (KC) and prone positioning in
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the incubator. Total pain scores were lower at 30, 60, and 90 seconds after heel stick with KC, but there was no significant difference noted 120 seconds after heel stick. When individual components of the pain score were analyzed, there were no significant differences in HR or SaO2 between groups. The heel stick procedure was not analyzed by individual phases. Ludington-Hoe et al. (2005) also studied pain response between heel stick received during KC compared with ‘ nesting’’ in warmer. The infants in that study were premature (
