513800
research-article2013
PENXXX10.1177/0148607113513800Journal of Parenteral and Enteral NutritionKeehn et al
Original Communication
Epidemiology of Interruptions to Nutrition Support in Critically Ill Children in the Pediatric Intensive Care Unit Alysha Keehn1; Christina O’Brien, BSc1; Vera Mazurak, PhD1; Kim Brunet-Wood, MSc, RD2; Ari Joffe, MD, FRCP(C)1,2; Allan de Caen, MD, FRCP(C)1,2; and Bodil Larsen, PhD, RD2,3
Journal of Parenteral and Enteral Nutrition Volume 39 Number 2 February 2015 211–217 © 2013 American Society for Parenteral and Enteral Nutrition DOI: 10.1177/0148607113513800 jpen.sagepub.com hosted at online.sagepub.com
Abstract Background: Nutrition support is often delayed or interrupted. The aim of this study is to identify reasons for and quantify time spent without nutrition in a mixed medical-surgical-cardiac pediatric intensive care unit (PICU). Methods: Data were prospectively collected to describe the patient cohort (anthropometrics and diagnostic category) and nutrition practices (time to nutrition initiation; frequency, duration, and causes of interruptions; and overall caloric intake). Descriptive statistics were used; comparisons of groups were performed using an independent t test and P < .05 as significance. Results: The mean (standard deviation) time to nutrition initiation was 22.8 (16.6) hours following admission; 35% of patients were initiated after >24 hours. Nutrition was interrupted 1.2 (2.0) times per patient. Time spent without nutrition due to interruptions was 11.6 (23.0) hours, up to 102 hours. Patients spent 42.4% (28.2%) of their median (range) PICU admission of 2.9 days (0.25–39 days) without any form of nutrition. Patients aged 0–6 months had a significantly higher mean number and duration of interruptions (P = .001 and P < .001, respectively) compared with children >6 months. Interruptions due to surgery and planned extubation lasted significantly longer than all other interruptions (P < .001 and P = .001, respectively). Pediatric Risk of Mortality (PRISM) III scores were not correlated with percentage of length of stay spent without nutrition (r = 0.137). Conclusions: Prolonged time to nutrition initiation and interruptions in delivery caused pediatric patients to spend a high proportion of admission without nutrition support, preventing most from meeting energy requirements. Further research addressing specific patient outcomes is required to define optimal initiation times and appropriate procedural-specific fasting times. (JPEN J Parenter Enteral Nutr. 2015;39:211-217)
Keywords pediatrics; enteral nutrition; parenteral nutrition; nutrition support teams; critical care
Clinical Relevancy Statement This study found that nutrition is being initiated on average 22.8 hours after admission, which current literature is suggesting is unnecessarily prolonged.1,2 It reveals inconsistent reasons for interrupting and delaying nutrition among health care practitioners and large cumulative caloric deficits over a patient’s admission. Patients are spending more than 40% of their admission without any form of nutrition and are meeting only approximately half of their energy requirements during that time. Contrary to hypotheses, no relationship was found between time spent without nutrition and Pediatric Risk of Mortality III scores, suggesting that severity of illness is not the driving force for suboptimal feeding practices. This work bears high clinical relevancy as it provides a strong justification for the development and implementation of standardized pediatric intensive care unit feeding protocols that improve patient care.
Introduction Nutrition support for critically ill children admitted to the pediatric intensive care unit (PICU) is important3 for many reasons,
including sustaining organ, cardiovascular, respiratory, and immune system functions until the acute phase inflammatory response resolves4; improving surgical and patient outcomes5;
From the 1University of Alberta, Edmonton, Alberta, Canada; 2Stollery Children’s Hospital, Edmonton, Alberta, Canada; and 3Alberta Health Services, Edmonton, Alberta, Canada. Financial disclosure: None declared. Received for publication April 15, 2013; accepted for publication October 30, 2013. This article originally appeared online on November 27, 2013. Corresponding Author: Bodil Larsen, PhD, RD, University of Alberta, 3G1.23 WMC, 8440-112 Street, Edmonton, AB Alberta T6G 2B7, Canada. Email: [email protected] Download a QR code reader on your smartphone, scan this image, and listen to the podcast for this article instantly. Or listen to this and other JPEN podcasts at http://pen.sage pub.com/site/misc/Index/Podcasts.xhtml.
Downloaded from pen.sagepub.com at GEORGIAN COURT UNIV on April 28, 2015
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Journal of Parenteral and Enteral Nutrition 39(2)
and reducing length of stay.6 Critically ill children are at risk of developing acute protein energy malnutrition (PEM) within 48 hours of admission to the PICU.7 Circumstances surrounding critical illness such as concurrent surgeries,8 procedures, and physiological instability7 complicate the delivery of nutrition therapy in this patient population.4,9 Providing early and adequate nutrition can improve nutrition indices and decrease the occurrence of PEM.10-12 Despite the importance of nutrition in the PICU population, prolonged time to initiation,1,10,11 frequent and potentially avoidable interruptions,1,13-15 and controversies surrounding when to withhold nutrition16 often result in large deficits in nutrition delivery over the length of a patient’s admissions.8 Implementation of nutrition support protocols has led to earlier initiation and reduced deficits of nutrition delivery in the PICU, especially when continually evaluated and adapted for current best practices.1,2 Large variations exist between practitioners as well as hospitals regarding practices related to prescribed nutrition and barriers to optimal delivery.14,16 Protocols must be developed to address the unique challenges and requirements of each individual hospital unit.17 The purpose of this study was to describe current practice surrounding nutrition delivery, specifically time to nutrition initiation and frequency, duration, and causes of interruptions, in a mixed medical-surgical-cardiac PICU and to identify subcategories of patients at risk of receiving suboptimal nutrition. A unique aspect of this study is that information was gathered in a prospective manner, with daily visits to the PICU by the study team, reducing inherent limitations that often affect retrospective studies. Other studies have described such practices but have had smaller sample sizes, placed exclusion criteria on patient enrollment, or were conducted in noncardiac PICU settings.1,2,9,13-15
Methods Approval for this study was obtained from the University of Alberta Health Research Ethics Board. One hundred consecutive patients admitted to the Stollery Children’s Hospital’s (SCH’s) 24-bed mixed medical-surgical-cardiac PICU were approached to be part of the study. Informed consent for participation was obtained from the patient’s parent or legal guardian after a clinician explained the study purpose and methodology. There were no exclusion criteria for the study. All usual feeding practices were unchanged as the study was strictly observational. No feeding protocol existed at the time of the study. Enteral nutrition (EN) was the preferred method when oral consumption was contraindicated or insufficient, and nasojejunal (NJ) feeding was the preferred modality when possible.18 Subcategories of patients were specified prior to study initiation, with the assistance of pediatric critical care practitioners, and included diagnostic, age, growth percentile, and Pediatric Risk of Mortality (PRISM) III score categories. Diagnostic categories were defined as cardiac surgery, general surgery (eg, craniotomy, transplant), and other admission (eg, trauma, respiratory failure). Age categories were 36 months. Growth percentile categories were 95th percentile (overweight).19 Growth percentiles were calculated using the Centers for Disease Control and Prevention (CDC) weight for length growth charts for patients younger than 2 years and CDC body mass index (BMI) for age percentile curves for those older than 2 years.20 PRISM III score categories were 12, whereby higher scores are increasingly predictive of mortality risk.21 Data were collected daily from medical charts using the Critical Care Information System (CCIS) program on the bedside computer. Information on demographics (age and sex), anthropometrics (weight, height, and growth percentile), and admitting diagnosis was recorded. The PRISM III score assigned to each patient on admission was also recorded. Patient energy requirements were calculated as per usual PICU feeding practices and based on the World Health Organization and Food and Agriculture Organization (WHO/FAO) predictive equations.22 Basal metabolic rate (BMR) was used to estimate energy requirements for patients who were receiving ventilatory support; estimated energy requirements (EERs) were used for patients who were not on ventilation. Explanation and validity of BMR and EER equations can be found elsewhere.22 Where patients had energy requirements measured by indirect calorimetry, that value was used preferentially (n = 4). The American Society for Parenteral and Enteral Nutrition’s (A.S.P.E.N.’s) definitions of nutrition support and nutrition therapy were used. Nutrition support is defined as EN and parenteral nutrition (PN).23 Nutrition therapy is defined as all forms of nutrition support described above, as well as any form of oral intake, including diet as tolerated (DAT), clear fluids (CF), and breastfeeding or bottle feeding.23 Data describing the nutrition therapy patients received over the entire PICU admission were recorded. The amount of time from admission until initiation of nutrition therapy was determined. Type of nutrition therapy and amount of nutrition support received were documented for each day of the patients’ admission. Percent of energy requirements received was calculated for patients receiving nutrition support only (ie, excluding patients with nutrition therapy, including oral intake) since calories received by food could not be accurately determined. All interruptions to nutrition therapy were recorded, including the reason, duration, and the type of nutrition therapy that was interrupted. Pediatric intensivists were consulted to categorize interruptions appropriately according to type of interruption (eg, to differentiate between surgical and procedural interruptions), but interruptions to nutrition were not further separated by the type of surgery or procedure due to the sample size and scope of the study. Total time spent without nutrition included time to initiation as well as time spent without nutrition due to interruptions. Discharge weights were determined by reviewing patient charts for the weights recorded on admission to the ward patients were transferred to upon discharge from the PICU. Change in body weight at discharge was calculated as a percentage of the weight on admission.
Downloaded from pen.sagepub.com at GEORGIAN COURT UNIV on April 28, 2015
Keehn et al
213 Table 2. Time to Initiation of Nutrition Therapy.
Table 1. Characteristics of the Study Cohort. Variable
Value
No. of patients Female Male Age, median (IQR), mo Age, % 36 mo Diagnostic category, % Cardiac surgery General surgery Other CDC growth chart percentile, mean (SD) CDC growth chart percentile, % 95th PRISM III score, median (IQR) PRISM III score, % 12 Duration of ventilatory support, median (IQR), d PICU LOS, median (IQR), d
100 46 54 17 (5–51) 30 41 29 44 18 38 48.1 (36.1) 21 65 14 4 (1.8–9) 58 31 11 1 (0–3) 2.9 (1.4–4.8)
CDC, Centers for Disease Control and Prevention; IQR, interquartile range; LOS, length of stay; PRISM III, Pediatric Risk of Mortality; SD, standard deviation.
Statistical Analysis Descriptive analyses were performed. Mean values were reported where a normal distribution existed and median values were reported when the data were not normally distributed. Pearson’s correlation tests were used to determine bivariate correlation coefficients between PRISM III score and percent length of stay (LOS) spent without nutrition therapy, time spent without nutrition, and percentage of energy requirements met and PICU LOS and hours spent without nutrition. A 2-tailed independent t test was used to determine if a significant difference in mean initiation times, frequency, or duration of interruptions and change in weight existed among groups. Analyses were computed using SPSS (version 20.0; SPSS, Inc, and IBM Company, Chicago, IL).
Results Description of Study Cohort Of the 101 patients admitted to the PICU during a period of 41 days (January–February 2012), 100 consented and were included in the study. One patient was not entered, as consent could not be gained due to a language barrier. The study cohort
Variable
Mean (SD) Time to Nutrition Initiation Following Admission, h
Time to initiation Diagnostic category Cardiac surgery General surgery Other admission Age category, mo 36 CDC growth chart percentile category 95th PRISM III score category 12
22.8 (16.6) 24.2 (15.3) 18.1 (16.4) 23.4 (17.6) 22.5 (17.6) 22.4 (16.6) 23.7 (15.2) 20.6 (19.5) 23.2 (13.6) 22.7 (23.1) 17.7 (15.3)a 27.8 (17.4) 33.8 (10.9)a
CDC, Centers for Disease Control and Prevention; PRISM III, Pediatric Risk of Mortality; SD, standard deviation. a Statistically significant difference in initiation times among patients with PRISM III scores 12 (P = .045).
(Table 1) consisted of an approximately equal proportion of male and female patients and large proportions of patients ≤36 months of age (71%), admitted for cardiac surgery (44%), receiving ventilatory support (63%), and with PRISM III scores 36 months.
Figure 1. Frequency of causes of interruptions to nutrition therapy. PICC, peripherally inserted central catheter.
Figure 2. Mean (SD bars) duration of time spent without nutrition due to identified interruptions. The mean duration of interruptions for surgery (P < .001) and extubation (P = .001) was significantly longer than the mean duration for all other interruptions. PICC, peripherally inserted central catheter.
interruptions compared with patients 7–36 months (P = .064) and >36 months (P < .001). The most frequent single cause of interruptions was planned extubation (24%) (Figure 1). Hemodynamic instability contributed to 7% of interruptions. “Other” reasons collectively comprised 35% of the interruptions, which included patient transfers within or between units (29%), procedures (chest tube removal, catheter insertion or
removal, biopsy, and extracorporeal membrane oxygenation decannulation) (15%), situations of high risk for aspiration (seizures, sedation issues, airway obstruction) (15%), medication administration (13%), red blood cell transfusion (3%), bathing (6%), and reasons that could not be determined (19%). Reasons for interruptions that resulted in the greatest duration
Downloaded from pen.sagepub.com at GEORGIAN COURT UNIV on April 28, 2015
Keehn et al
215
Discussion This study investigated the duration and causes of interruptions to nutrition support in the PICU. The major findings were that prolonged time to initiation and interruptions for surgery and extubation were major contributing factors to the time patients spent without nutrition. On average, patients spent more than 40% of their LOS without nutrition while meeting just over half of their energy requirements. No correlation existed between severity of illness, measured by PRISM III score, and time spent without nutrition, and less than 10% of all identified interruptions were due to patient instability.
Prolonged Initiation Figure 3. Correlation between mean percent of energy requirements met over pediatric intensive care unit length of stay (LOS) and percentage LOS spent without nutrition in patients receiving nutrition support (n = 67) (r = −0.674; P < .001).
of time spent without nutrition therapy were surgery (P < .001) and extubation (P = .001). Duration of interruptions due to these 2 causes was significantly longer than all other causes of interruptions (Figure 2). The longest interruption to nutrition therapy was due to a combination of instability, peripherally inserted central catheter line insertion, and “other” and lasted 102 hours.
Proportion of Energy Requirements Received The mean (SD) percentage of PICU LOS without nutrition therapy was 42.4% (28.4%). Patients receiving nutrition support (n = 67) met 55% (46.5%) of their energy requirements and 42% (39.8%) of their protein requirements over the course of their admission. No significant differences in the proportion of PICU LOS spent without nutrition therapy were found between subgroups. There was a positive correlation (r = 0.412; P < .001) between PICU LOS and hours spent without nutrition. There was a negative correlation (r = −0.674; P = .001) between time spent without nutrition and percentage of energy requirements met (Figure 3).
Change in Weight as an Outcome Measure No statistically significant difference in the percent change in body weight existed between age categories. Patients 37 months lost an average of 1.6% of their admission body weight. There was no correlation between the amount of time patients spent without nutrition therapy over their PICU LOS and the percent change in body weight.
There has been the suggestion that initiation times of nutrition therapy in the PICU setting are unnecessarily prolonged.6,9,14 The results of this study are consistent with Taylor et al,13 who reported 59% of patients to be initiated within the first 24 hours of admission, and Mehta et al,9 who reported mean time to initiation to be 24 hours with a range of 0–3.5 days. Despite the lack of clear evidence-based initiation recommendations for this patient population, it has been suggested that the initiation of feeding be done within the first 24 hours whenever possible to improve caloric intake and energy balance.14 Tume et al1 reported a reduced time to initiation when a nutrition support protocol that guided physicians to initiate nutrition within 6 hours of admission was implemented in their PICU. Upon first audit of their protocol, they found the mean time to initiation to be reduced to 11.9 hours with only 35% adherence to the protocol. Similarly, Meyer et al2 audited nutrition practices after the implementation of a nutrition support protocol and found that median time to initiation was 15 hours after the first audit and reduced to 4.5 hours after the fourth audit of the protocol. These findings suggest that results obtained in the present study are similar to other centers prior to initiating protocols and that adoption of an appropriate protocol holds promise for improving nutrition delivery to patients in the PICU. Improvement of patient outcomes could be expected when caloric deficits are minimized. This study found significantly longer initiation times among patients with PRISM III scores >12 compared with those with scores
research-article2013
PENXXX10.1177/0148607113513800Journal of Parenteral and Enteral NutritionKeehn et al
Original Communication
Epidemiology of Interruptions to Nutrition Support in Critically Ill Children in the Pediatric Intensive Care Unit Alysha Keehn1; Christina O’Brien, BSc1; Vera Mazurak, PhD1; Kim Brunet-Wood, MSc, RD2; Ari Joffe, MD, FRCP(C)1,2; Allan de Caen, MD, FRCP(C)1,2; and Bodil Larsen, PhD, RD2,3
Journal of Parenteral and Enteral Nutrition Volume 39 Number 2 February 2015 211–217 © 2013 American Society for Parenteral and Enteral Nutrition DOI: 10.1177/0148607113513800 jpen.sagepub.com hosted at online.sagepub.com
Abstract Background: Nutrition support is often delayed or interrupted. The aim of this study is to identify reasons for and quantify time spent without nutrition in a mixed medical-surgical-cardiac pediatric intensive care unit (PICU). Methods: Data were prospectively collected to describe the patient cohort (anthropometrics and diagnostic category) and nutrition practices (time to nutrition initiation; frequency, duration, and causes of interruptions; and overall caloric intake). Descriptive statistics were used; comparisons of groups were performed using an independent t test and P < .05 as significance. Results: The mean (standard deviation) time to nutrition initiation was 22.8 (16.6) hours following admission; 35% of patients were initiated after >24 hours. Nutrition was interrupted 1.2 (2.0) times per patient. Time spent without nutrition due to interruptions was 11.6 (23.0) hours, up to 102 hours. Patients spent 42.4% (28.2%) of their median (range) PICU admission of 2.9 days (0.25–39 days) without any form of nutrition. Patients aged 0–6 months had a significantly higher mean number and duration of interruptions (P = .001 and P < .001, respectively) compared with children >6 months. Interruptions due to surgery and planned extubation lasted significantly longer than all other interruptions (P < .001 and P = .001, respectively). Pediatric Risk of Mortality (PRISM) III scores were not correlated with percentage of length of stay spent without nutrition (r = 0.137). Conclusions: Prolonged time to nutrition initiation and interruptions in delivery caused pediatric patients to spend a high proportion of admission without nutrition support, preventing most from meeting energy requirements. Further research addressing specific patient outcomes is required to define optimal initiation times and appropriate procedural-specific fasting times. (JPEN J Parenter Enteral Nutr. 2015;39:211-217)
Keywords pediatrics; enteral nutrition; parenteral nutrition; nutrition support teams; critical care
Clinical Relevancy Statement This study found that nutrition is being initiated on average 22.8 hours after admission, which current literature is suggesting is unnecessarily prolonged.1,2 It reveals inconsistent reasons for interrupting and delaying nutrition among health care practitioners and large cumulative caloric deficits over a patient’s admission. Patients are spending more than 40% of their admission without any form of nutrition and are meeting only approximately half of their energy requirements during that time. Contrary to hypotheses, no relationship was found between time spent without nutrition and Pediatric Risk of Mortality III scores, suggesting that severity of illness is not the driving force for suboptimal feeding practices. This work bears high clinical relevancy as it provides a strong justification for the development and implementation of standardized pediatric intensive care unit feeding protocols that improve patient care.
Introduction Nutrition support for critically ill children admitted to the pediatric intensive care unit (PICU) is important3 for many reasons,
including sustaining organ, cardiovascular, respiratory, and immune system functions until the acute phase inflammatory response resolves4; improving surgical and patient outcomes5;
From the 1University of Alberta, Edmonton, Alberta, Canada; 2Stollery Children’s Hospital, Edmonton, Alberta, Canada; and 3Alberta Health Services, Edmonton, Alberta, Canada. Financial disclosure: None declared. Received for publication April 15, 2013; accepted for publication October 30, 2013. This article originally appeared online on November 27, 2013. Corresponding Author: Bodil Larsen, PhD, RD, University of Alberta, 3G1.23 WMC, 8440-112 Street, Edmonton, AB Alberta T6G 2B7, Canada. Email: [email protected] Download a QR code reader on your smartphone, scan this image, and listen to the podcast for this article instantly. Or listen to this and other JPEN podcasts at http://pen.sage pub.com/site/misc/Index/Podcasts.xhtml.
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212
Journal of Parenteral and Enteral Nutrition 39(2)
and reducing length of stay.6 Critically ill children are at risk of developing acute protein energy malnutrition (PEM) within 48 hours of admission to the PICU.7 Circumstances surrounding critical illness such as concurrent surgeries,8 procedures, and physiological instability7 complicate the delivery of nutrition therapy in this patient population.4,9 Providing early and adequate nutrition can improve nutrition indices and decrease the occurrence of PEM.10-12 Despite the importance of nutrition in the PICU population, prolonged time to initiation,1,10,11 frequent and potentially avoidable interruptions,1,13-15 and controversies surrounding when to withhold nutrition16 often result in large deficits in nutrition delivery over the length of a patient’s admissions.8 Implementation of nutrition support protocols has led to earlier initiation and reduced deficits of nutrition delivery in the PICU, especially when continually evaluated and adapted for current best practices.1,2 Large variations exist between practitioners as well as hospitals regarding practices related to prescribed nutrition and barriers to optimal delivery.14,16 Protocols must be developed to address the unique challenges and requirements of each individual hospital unit.17 The purpose of this study was to describe current practice surrounding nutrition delivery, specifically time to nutrition initiation and frequency, duration, and causes of interruptions, in a mixed medical-surgical-cardiac PICU and to identify subcategories of patients at risk of receiving suboptimal nutrition. A unique aspect of this study is that information was gathered in a prospective manner, with daily visits to the PICU by the study team, reducing inherent limitations that often affect retrospective studies. Other studies have described such practices but have had smaller sample sizes, placed exclusion criteria on patient enrollment, or were conducted in noncardiac PICU settings.1,2,9,13-15
Methods Approval for this study was obtained from the University of Alberta Health Research Ethics Board. One hundred consecutive patients admitted to the Stollery Children’s Hospital’s (SCH’s) 24-bed mixed medical-surgical-cardiac PICU were approached to be part of the study. Informed consent for participation was obtained from the patient’s parent or legal guardian after a clinician explained the study purpose and methodology. There were no exclusion criteria for the study. All usual feeding practices were unchanged as the study was strictly observational. No feeding protocol existed at the time of the study. Enteral nutrition (EN) was the preferred method when oral consumption was contraindicated or insufficient, and nasojejunal (NJ) feeding was the preferred modality when possible.18 Subcategories of patients were specified prior to study initiation, with the assistance of pediatric critical care practitioners, and included diagnostic, age, growth percentile, and Pediatric Risk of Mortality (PRISM) III score categories. Diagnostic categories were defined as cardiac surgery, general surgery (eg, craniotomy, transplant), and other admission (eg, trauma, respiratory failure). Age categories were 36 months. Growth percentile categories were 95th percentile (overweight).19 Growth percentiles were calculated using the Centers for Disease Control and Prevention (CDC) weight for length growth charts for patients younger than 2 years and CDC body mass index (BMI) for age percentile curves for those older than 2 years.20 PRISM III score categories were 12, whereby higher scores are increasingly predictive of mortality risk.21 Data were collected daily from medical charts using the Critical Care Information System (CCIS) program on the bedside computer. Information on demographics (age and sex), anthropometrics (weight, height, and growth percentile), and admitting diagnosis was recorded. The PRISM III score assigned to each patient on admission was also recorded. Patient energy requirements were calculated as per usual PICU feeding practices and based on the World Health Organization and Food and Agriculture Organization (WHO/FAO) predictive equations.22 Basal metabolic rate (BMR) was used to estimate energy requirements for patients who were receiving ventilatory support; estimated energy requirements (EERs) were used for patients who were not on ventilation. Explanation and validity of BMR and EER equations can be found elsewhere.22 Where patients had energy requirements measured by indirect calorimetry, that value was used preferentially (n = 4). The American Society for Parenteral and Enteral Nutrition’s (A.S.P.E.N.’s) definitions of nutrition support and nutrition therapy were used. Nutrition support is defined as EN and parenteral nutrition (PN).23 Nutrition therapy is defined as all forms of nutrition support described above, as well as any form of oral intake, including diet as tolerated (DAT), clear fluids (CF), and breastfeeding or bottle feeding.23 Data describing the nutrition therapy patients received over the entire PICU admission were recorded. The amount of time from admission until initiation of nutrition therapy was determined. Type of nutrition therapy and amount of nutrition support received were documented for each day of the patients’ admission. Percent of energy requirements received was calculated for patients receiving nutrition support only (ie, excluding patients with nutrition therapy, including oral intake) since calories received by food could not be accurately determined. All interruptions to nutrition therapy were recorded, including the reason, duration, and the type of nutrition therapy that was interrupted. Pediatric intensivists were consulted to categorize interruptions appropriately according to type of interruption (eg, to differentiate between surgical and procedural interruptions), but interruptions to nutrition were not further separated by the type of surgery or procedure due to the sample size and scope of the study. Total time spent without nutrition included time to initiation as well as time spent without nutrition due to interruptions. Discharge weights were determined by reviewing patient charts for the weights recorded on admission to the ward patients were transferred to upon discharge from the PICU. Change in body weight at discharge was calculated as a percentage of the weight on admission.
Downloaded from pen.sagepub.com at GEORGIAN COURT UNIV on April 28, 2015
Keehn et al
213 Table 2. Time to Initiation of Nutrition Therapy.
Table 1. Characteristics of the Study Cohort. Variable
Value
No. of patients Female Male Age, median (IQR), mo Age, % 36 mo Diagnostic category, % Cardiac surgery General surgery Other CDC growth chart percentile, mean (SD) CDC growth chart percentile, % 95th PRISM III score, median (IQR) PRISM III score, % 12 Duration of ventilatory support, median (IQR), d PICU LOS, median (IQR), d
100 46 54 17 (5–51) 30 41 29 44 18 38 48.1 (36.1) 21 65 14 4 (1.8–9) 58 31 11 1 (0–3) 2.9 (1.4–4.8)
CDC, Centers for Disease Control and Prevention; IQR, interquartile range; LOS, length of stay; PRISM III, Pediatric Risk of Mortality; SD, standard deviation.
Statistical Analysis Descriptive analyses were performed. Mean values were reported where a normal distribution existed and median values were reported when the data were not normally distributed. Pearson’s correlation tests were used to determine bivariate correlation coefficients between PRISM III score and percent length of stay (LOS) spent without nutrition therapy, time spent without nutrition, and percentage of energy requirements met and PICU LOS and hours spent without nutrition. A 2-tailed independent t test was used to determine if a significant difference in mean initiation times, frequency, or duration of interruptions and change in weight existed among groups. Analyses were computed using SPSS (version 20.0; SPSS, Inc, and IBM Company, Chicago, IL).
Results Description of Study Cohort Of the 101 patients admitted to the PICU during a period of 41 days (January–February 2012), 100 consented and were included in the study. One patient was not entered, as consent could not be gained due to a language barrier. The study cohort
Variable
Mean (SD) Time to Nutrition Initiation Following Admission, h
Time to initiation Diagnostic category Cardiac surgery General surgery Other admission Age category, mo 36 CDC growth chart percentile category 95th PRISM III score category 12
22.8 (16.6) 24.2 (15.3) 18.1 (16.4) 23.4 (17.6) 22.5 (17.6) 22.4 (16.6) 23.7 (15.2) 20.6 (19.5) 23.2 (13.6) 22.7 (23.1) 17.7 (15.3)a 27.8 (17.4) 33.8 (10.9)a
CDC, Centers for Disease Control and Prevention; PRISM III, Pediatric Risk of Mortality; SD, standard deviation. a Statistically significant difference in initiation times among patients with PRISM III scores 12 (P = .045).
(Table 1) consisted of an approximately equal proportion of male and female patients and large proportions of patients ≤36 months of age (71%), admitted for cardiac surgery (44%), receiving ventilatory support (63%), and with PRISM III scores 36 months.
Figure 1. Frequency of causes of interruptions to nutrition therapy. PICC, peripherally inserted central catheter.
Figure 2. Mean (SD bars) duration of time spent without nutrition due to identified interruptions. The mean duration of interruptions for surgery (P < .001) and extubation (P = .001) was significantly longer than the mean duration for all other interruptions. PICC, peripherally inserted central catheter.
interruptions compared with patients 7–36 months (P = .064) and >36 months (P < .001). The most frequent single cause of interruptions was planned extubation (24%) (Figure 1). Hemodynamic instability contributed to 7% of interruptions. “Other” reasons collectively comprised 35% of the interruptions, which included patient transfers within or between units (29%), procedures (chest tube removal, catheter insertion or
removal, biopsy, and extracorporeal membrane oxygenation decannulation) (15%), situations of high risk for aspiration (seizures, sedation issues, airway obstruction) (15%), medication administration (13%), red blood cell transfusion (3%), bathing (6%), and reasons that could not be determined (19%). Reasons for interruptions that resulted in the greatest duration
Downloaded from pen.sagepub.com at GEORGIAN COURT UNIV on April 28, 2015
Keehn et al
215
Discussion This study investigated the duration and causes of interruptions to nutrition support in the PICU. The major findings were that prolonged time to initiation and interruptions for surgery and extubation were major contributing factors to the time patients spent without nutrition. On average, patients spent more than 40% of their LOS without nutrition while meeting just over half of their energy requirements. No correlation existed between severity of illness, measured by PRISM III score, and time spent without nutrition, and less than 10% of all identified interruptions were due to patient instability.
Prolonged Initiation Figure 3. Correlation between mean percent of energy requirements met over pediatric intensive care unit length of stay (LOS) and percentage LOS spent without nutrition in patients receiving nutrition support (n = 67) (r = −0.674; P < .001).
of time spent without nutrition therapy were surgery (P < .001) and extubation (P = .001). Duration of interruptions due to these 2 causes was significantly longer than all other causes of interruptions (Figure 2). The longest interruption to nutrition therapy was due to a combination of instability, peripherally inserted central catheter line insertion, and “other” and lasted 102 hours.
Proportion of Energy Requirements Received The mean (SD) percentage of PICU LOS without nutrition therapy was 42.4% (28.4%). Patients receiving nutrition support (n = 67) met 55% (46.5%) of their energy requirements and 42% (39.8%) of their protein requirements over the course of their admission. No significant differences in the proportion of PICU LOS spent without nutrition therapy were found between subgroups. There was a positive correlation (r = 0.412; P < .001) between PICU LOS and hours spent without nutrition. There was a negative correlation (r = −0.674; P = .001) between time spent without nutrition and percentage of energy requirements met (Figure 3).
Change in Weight as an Outcome Measure No statistically significant difference in the percent change in body weight existed between age categories. Patients 37 months lost an average of 1.6% of their admission body weight. There was no correlation between the amount of time patients spent without nutrition therapy over their PICU LOS and the percent change in body weight.
There has been the suggestion that initiation times of nutrition therapy in the PICU setting are unnecessarily prolonged.6,9,14 The results of this study are consistent with Taylor et al,13 who reported 59% of patients to be initiated within the first 24 hours of admission, and Mehta et al,9 who reported mean time to initiation to be 24 hours with a range of 0–3.5 days. Despite the lack of clear evidence-based initiation recommendations for this patient population, it has been suggested that the initiation of feeding be done within the first 24 hours whenever possible to improve caloric intake and energy balance.14 Tume et al1 reported a reduced time to initiation when a nutrition support protocol that guided physicians to initiate nutrition within 6 hours of admission was implemented in their PICU. Upon first audit of their protocol, they found the mean time to initiation to be reduced to 11.9 hours with only 35% adherence to the protocol. Similarly, Meyer et al2 audited nutrition practices after the implementation of a nutrition support protocol and found that median time to initiation was 15 hours after the first audit and reduced to 4.5 hours after the fourth audit of the protocol. These findings suggest that results obtained in the present study are similar to other centers prior to initiating protocols and that adoption of an appropriate protocol holds promise for improving nutrition delivery to patients in the PICU. Improvement of patient outcomes could be expected when caloric deficits are minimized. This study found significantly longer initiation times among patients with PRISM III scores >12 compared with those with scores
