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CE Online and Journal Club Feature

Nutritional Adequacy in Patients Receiving Mechanical Ventilation Who Are Fed Enterally

	Abstract

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• Background Inadequate nutritional intake in critically ill patients can lead to complications resulting in increased mortality and healthcare costs. Several factors limit adequate nutritional intake in intensive care unit patients given enteral feedings.

• Objective To examine the adequacy of enteral nutritional intake and the factors that affect its delivery in patients receiving mechanical ventilation.

• Methods A prospective, descriptive design was used to study 60 patients receiving enteral feedings at target or goal rate. Energy requirements were determined for the entire sample by using the Harris-Benedict equation; energy requirements for a subset of 25 patients were also determined by using indirect calorimetry. Energy received via enteral feeding and reason and duration of interruptions in feedings were recorded for 3 consecutive days.

• Results Mean estimated energy requirements (8996 kJ, SD 1326 kJ) and mean energy intake received (5899 kJ, SD 3058 kJ) differed significantly (95% CI 3297-3787; P < .001). A total of 41 patients (68.3%) received less than 90% of their required energy intake, 18 (30.0%) received within ±10%, and 1 (1.7%) received more than 110%. Episodes of diarrhea, emesis, large residual volumes, feeding tube replacements, and interruptions for procedures accounted for 70% of the variance in energy received (P<.001). Procedural interruptions alone accounted for 45% of the total variance. Estimated energy requirements determined via indirect calorimetry and mean energy received did not differ.

• Conclusions Most critically ill patients receiving mechanical ventilation who are fed enterally do not receive their energy requirements, primarily because of frequent interruptions in enteral feedings.

Accurately assessing nutritional requirements and monitoring the adequacy of nutritional intake in critically ill patients can help ensure that complications associated with underfeeding or overfeeding are avoided. Mathematical estimates of energy requirements are the most common method of determining energy needs in these patients. Traditionally, the Harris-Benedict equation (HBE) has been the accepted standard for determining the energy requirements of critically ill patients. In 1919, Harris and Benedict¹⁵ reported the results of a study done in healthy adult volunteers to determine daily energy expenditure. Regression equations were calculated for men and women on the basis of body weight, age, and height. The HBE was derived from this regression analysis to provide estimates of the basal energy expenditure for healthy persons at rest. In order to account for the increased energy expenditure during acute illness and injury, disease-specific equations^16,17 and stress factors that account for activity and injury have been developed to improve the accuracy of the HBE in hospitalized patients.^17,18 Despite these modifications for critically ill patients, the accuracy of the HBE is limited in ventilator-dependent patients, patients who are either morbidly obese or severely malnourished and underweight, transplant patients, and patients with marked fluid overload, ascites, extensive limb amputations, or paraplegia.^19,20

Using indirect calorimetry to measure energy expenditure is an alternative method of estimating nutritional requirements that is more accurate than the HBE in critically ill patients.^20,21 In this method, energy expenditure is calculated indirectly by measuring pulmonary gas exchange.¹⁹ Strict adherence to measurement criteria is required because of the numerous factors that affect energy expenditure. Technical limitations and the associated costs of indirect calorimetry limit its usefulness in measuring energy expenditure in critically ill patients.²² Unstable hemodynamic conditions, agitation, cuff leaks, and increased oxygen requirements may preclude use of indirect calorimetry. Because of the limitations of using indirect calorimetry, the HBE remains the most commonly used method for assessing energy requirements in critically ill patients.^22,23

Recent studies^7,8 indicated that repeated interruptions of enteral tube feeding result in significant underfeeding in critically ill patients. Adam and Batson⁷ found that ICU patients received only 76% of the patients’ daily energy requirements with enteral tube feeding, primarily because of gastrointestinal intolerance and elective withholding of feedings for procedures. In a similar study, McClave et al⁸ found that ICU patients received only 52% of the patients’ energy requirements with enteral tube feeding and that 66% of the interruptions in tube feedings were avoidable. In both studies,^7,8 the authors assumed that the estimated energy requirement of ICU patients was 105 to 146 kJ/kg per day (25–35 kcal/kg per day), a significant underestimation of energy requirements in critically ill patients.²⁴ Neither group of investigators^7,8 used either the HBE or indirect calorimetry to estimate energy needs.

Although both groups reported the type and frequency of interruptions of tube feedings, only McClave et al documented the duration of interruptions attributable to each reason for cessation of tube feedings. In the study by McClave et al, for each patient, the study period began as soon as the feeding tube was inserted. Therefore, the patients were adjusting to enteral feedings. To date, no investigators waited until patients had achieved goal rates for enteral feedings to begin measurements.

Repeated interruptions of enteral tube feedings result in significant underfeeding in critically ill patients.

 

In the study reported here, we assessed the adequacy of enteral intake in ICU patients receiving mechanical ventilation once the prescribed tube feeding rate had been achieved. We also determined the factors affecting the delivery of enteral feedings in these patients. The primary aims of the study were to compare the number of kilojoules patients received via enteral feedings with the patients’ estimated energy requirements as indicated by the HBE and by indirect calorimetry and to determine the factors that affect the delivery of enteral feedings in critically ill patients.

	Methods

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Sample and Setting
Data were prospectively collected during an 18-month period between May 2001 and October 2002 on a convenience sample of 60 adults. Patients were selected from three 15-bed ICUs located at 2 study sites: the medical-surgical ICU at the Palo Alto Veterans Affairs Health Care System hospital and a coronary care unit and a medical ICU in a county hospital. The institutional review boards of both facilities approved the research protocol, and written informed consent was obtained from all patients or the patients’ healthcare surrogates. Patients were eligible for the study if they were 18 years or older, intubated and receiving mechanical ventilation, and receiving enteral tube feedings at the prescribed goal rate. Patients were excluded if they were receiving parenteral or oral feedings at the time of enrollment.

Data Collection
Baseline demographic data included age, height, weight, sex, and body mass index; hospital and ICU admission dates; diagnosis at admission and/or surgical procedure; values on the Simplified Acute Physiology Score II; type of feeding tube used and the date of insertion; the date and time that enteral tube feeding began; and the date and time that the tube feeding goal rate was achieved. An ICU dietitian determined the initial nutritional needs and energy requirements of each study patient by using the HBE with stress-related factors ranging from 1.3 to 1.5.²⁵ In addition, in 25 of the 60 patients, resting energy expenditure (REE) was measured by using indirect calorimetry at the beginning of the study period by using a metabolic cart (Vmax 29n Spectra, Sensor Medics, Yorba Linda, Calif). Before each measurement, the gas analyzers were calibrated according to the manufacturer’s specifications. Once calibration was completed and steady-state oxygen consumption and carbon dioxide production had been achieved (<10% change in the 2 parameters during a 5-minute period), oxygen consumption and carbon dioxide production were measured continuously and averaged during a 30-minute period; data collected during the first 5 minutes were discarded.^26,27 REE was then estimated from the mean values of oxygen consumption and carbon dioxide production by using the modified Weir equation.²⁸

Logistic and technical difficulties precluded use of indirect calorimetry in 35 patients. Unstable or high (>80%) levels of inspired oxygen, early discontinuation of mechanical ventilation, and unavailability of a technician accounted for the majority (60%) of the reasons why indirect calorimetry could not be performed. Other reasons included cuff leaks, the patients’ agitation, or unstable hemodynamic condition. The technical and clinical difficulties of measuring energy expenditure in ICU patients have been described previously.^29,30

Once the goal rate for tube feeding was achieved, nutritional data for each patient were recorded daily for 3 consecutive days by one researcher (CMO). Nutritional data included daily weight, type of enteral formula used, tube feeding infusion rate, volume of tube feedings infused during 24 hours, reasons for and duration of interruptions of tube feedings, gastric residual volumes (measured every 4–6 hours), the number of episodes of emesis and diarrhea, and the number of times the feeding tube was replaced. Daily energy intake was determined on the basis of the volume and type of enteral formula administered. The mean amount of energy received during the 3-day period was then calculated.

Seven patients also received continuous propofol infusions for sedation during the study period. Propofol is formulated in a lipid emulsion and when administered as a continuous infusion may contribute significantly to a patient’s daily energy intake.³¹ Energy received from both enteral nutrition and propofol infusions was included in the determination of nutritional adequacy for those patients who received propofol.

Data Analysis
SPSS, version 11.0 (SPSS Inc, Chicago, Ill), was used to analyze data. Descriptive statistics were used to characterize the sample. Chi-square and independent sample t tests were used to determine the differences between patients who had indirect calorimetry and those who did not. Two-tailed, paired Student t tests were used to determine differences between mean energy required and mean energy received. Multiple linear regression analysis was used to examine the effects of clinical predictor variables on the percentage of required enteral feeding actually received. A P value of less than .05 was selected as the level of significance. The nQuery Advisory software program (Statistical Solutions, Saugus, Mass) was used to calculate the sample size for a multiple linear-regression model that included 4 predictors with an R² of 0.4. A sample size of 60 was required (ß = .80, P = .05).

	Results

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Of the 64 patients who consented to participate in the study, 4 were withdrawn because their goal tube feeding rate was not reached before extubation. Table 1 gives the demographic and enteral feeding characteristics of the 60 patients included in the study. Mann-Whitney tests revealed no significant differences between study sites for age (P = .07), body mass index (P = .28), or values on the Simplified Acute Physiology Score II (P = .79), and the Fisher exact test revealed no significant difference between study sites in whether or not patients had surgery (P = .10). However, the percentage of men and women in the sample differed significantly between the sites (P < .001).

For the total sample of 60 patients, the mean estimated energy requirement of 8996 kJ (SD 1326 kJ; 2150 kcal, SD 317 kcal) determined by using the HBE and the mean daily energy intake of 5899 kJ (SD 3058 kJ; 1410 kcal, SD 731 kcal) differed significantly (95% CI 2397–3787 kJ [573–905 kcal], P < .001; Table 2). In the 25 patients whose energy requirements were also measured by using indirect calorimetry, differences between mean measured REE and mean daily energy intake were not significant (P = .34).

Univariate analysis of the predictor variables was used to determine factors that significantly correlated with the percentage of required energy received. The 5 variables were number of episodes of diarrhea (r= 0.257, P=.05), episodes of emesis (r= –0.202, P=.12), feeding tube replacements (r = –0.364, P = .004), mean gastric residual volume (r = –0.267, P = .04), and the number of minutes tube feedings were withheld for any reason (r = 0.830, P < .001). Multiple linear regression analysis was used to detect the influence of specific factors on energy intake from enteral feedings.

The 5 variables accounted for more than 70% of the variance in the percentage of required energy received. Table 4 indicates the unique contribution of each variable. The mean number of minutes that feedings were withheld accounted for the majority of the variance observed (sr² = 0.453; P < .001). An additional hierarchical regression analysis in which the variable mean number of minutes feedings were withheld was excluded revealed that 25% of the variance in percentage of required energy received was accounted for by the other 4 variables (R² = 0.25, P < .01). As the mean number of minutes that feedings were held increased, the percentage of required energy received dramatically decreased. Feedings were withheld a mean of 7 h/d (422 minutes, SD 351 minutes).

The reasons why tube feedings were withheld for at least 15 minutes per episode are summarized in Table 5. The interruption of tube feedings for ICU-related factors accounted for almost 70% of the total time that feedings were withheld. More than 50% of these episodes of withholding were related to scheduled surgeries and planned extubations. Gastrointestinal intolerance (eg, increased gastric residual volume, emesis, abdominal pain or distention, and diarrhea) occurred in 36.7% of patients, but accounted for only 19.8% of the total time that feedings were withheld. Although interruptions in tube feedings due to nursing care occurred in 33.3% of patients, nursing care accounted for only 2.5% of the total time feedings were off. Factors related to obstruction, dislodgement, and replacement of feeding tubes accounted for only 11.1% of the total time that feedings were withheld.

	Discussion

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Despite the known benefits of enteral feeding, ICU patients may not always receive adequate enteral feeding because of frequent interruptions of their tube feedings. We found that more than two thirds of ICU patients treated with mechanical ventilation received less than 90% of their nutritional requirements, as determined by using the HBE, via enteral tube feeding; half of these patients received less than 50% of their required energy during the 3-day study period.

Our results are consistent with the findings of at least 2 major studies of enteral feeding patterns in critically ill patients.^7–9,14 In one study,⁷ 193 medical and surgical adult ICU patients received only 76% of their prescribed enteral feedings. In another study,⁸ 44 medical and surgical ICU and coronary care unit patients treated with mechanical ventilation received only 52% of their required energy via enteral feeding, and the volume of enteral feeding ranged from 15% to 87% of requirements. In both of these studies, patients were followed up from the time of initiation of their tube feedings and the various reasons for interruptions in tube feedings were then determined and counted.

In our study, each patient’s tube feeding intake was examined only after the target infusion rate had been achieved, rather than at the start of enteral feeding as in previous studies. With this step, we were able to separate gastrointestinal intolerance, which often limits enteral feeding early on, from other factors that affect delivery of enteral feedings. We also specifically focused on ICU patients receiving mechanical ventilation, who are at particular risk for poor outcomes related to malnutrition.¹⁰

Multiple factors contribute to inadequate delivery of enteral feedings in critically ill patients, including gastrointestinal problems (eg, large gastric residual volumes, emesis, abdominal pain and distention, and diarrhea),^12,13 frequent interruptions due to surgery and ICU-related procedures,^7,8,11,32 problems related to the feeding tube (eg, tube dislodgement or occlusion),^8,9 and inaccurate assessment of nutritional requirements.^33,34 Although emesis was not significantly correlated with the percentage of energy received in our study (r= –0.202, P = .12), we selected it as a variable because it affects enteral intake.^8,12,13 In a recent study, Mentec et al¹² found that gastric atony with delayed gastric emptying was common in both medical and surgical ICU patients and was a common cause of tube feeding intolerance due to large gastric residual volumes. It is associated with an increased risk of gastric reflux, aspiration, and pneumonia. In the previous studies by Adam and Batson⁷ and McClave et al,⁸ gastrointestinal intolerance was the most common cause of inadequate delivery of enteral feedings in ICU patients, accounting for 73% of the interruptions in tube feedings in the study by Adam and Batson and affecting 45% of patients in the study by McClave et al. In contrast, in our study, gastrointestinal intolerance occurred in 36.7% of patients and accounted for only 19.8% of the total time that tube feedings were withheld. This finding reflects the fact that we studied patients only after they had initially reached their target tube feeding rates, thereby eliminating patients who were initially unable to tolerate enteral feedings. In addition, the percentage of patients who had gastrointestinal intolerance in our study might have been low because the majority of our patients were fed into the small bowel, a practice that is associated with a lower incidence of gastrointestinal intolerance than is gastric feeding.^12,13

In our study, ICU tests and procedures were the most common cause of interruptions in tube feeding. Patients in the ICU may be required to receive nothing by mouth in preparation for scheduled surgical procedures or diagnostic testing, in order to minimize the risk of gastric reflux and pulmonary aspiration. ICU patients often have multiple tests and procedures, which may require that the patients’ enteral feedings be withheld for hours or days at a time in anticipation of these procedures. Tube feedings may not be immediately resumed after a procedure if patients are recovering from sedatives or anesthetics administered during the procedure.

ICU tests and procedures rather than problems with feeding tubes were the most common cause of interruptions in tube feedings.

 

In our study, tube feedings were withheld a mean of 7 h/d during the 3-day study period. They were withheld at least once a day in 59 patients (98.3%) and between 2 and 4 times per day in 43 patients (71.7%). ICU-related procedures accounted for almost 70% of the total time feedings were held in our study; extubation and surgical procedures accounted for 28.8% and 23.4%, respectively, of the total time feedings were off (Table 5). In previous studies,^7,8 ICU-related procedures were less likely than gastrointestinal intolerance to cause interruptions in tube feeding. In the study of Adam and Batson,⁷ 42% of feeding interruptions were due to ICU-related procedures. In the study of McClave et al,⁸ 39% of patients had feedings interrupted for ICU procedures; these interruptions accounted for 35% of the total time feedings were off. Similar to our findings, schedule delays for surgeries or diagnostic procedures often led to feeding interruptions of more than 24 hours.⁸

Problems with the patency and positioning of feeding tubes can affect the adequacy of enteral nutritional intake.^8,9 In our study, issues related to problems with feeding tubes were not major causes of interruptions in feeding. Problems with tube patency affected only 5 patients (8.3%) and accounted for only 4.2% of the time feedings were held. Dislodgement of the feeding tube resulted in the interruption of tube feedings in only 8 patients (13.3%) and accounted for only 4.6% of the total time feedings were withheld. These findings are in contrast to those of McClave et al⁸; in their study, dislodgement of the feeding tube was the second most common cause of interruptions in tube feedings and occurred in 41% of the patients they studied. However, dislodgement accounted for only 7% of the total time that feedings were withheld.

In a study of neurosurgical ICU patients by Stechmiller et al,⁹ dislodgement of the feeding tube was also a common reason for interruptions in tube feedings, affecting 27% of the patients studied. In contrast to our findings, in the study by Stechmiller et al, administration of medications was the most common reason for interruptions in tube feedings, occurring in 31% of patients. In our study, administration of medications affected only 3.3% of the patients studied, and accounted for only 1.8% of the total time that tube feedings were withheld. This difference may reflect the difference in the populations of patients studied; the neurosurgical patients in the study of Stechmiller et al were receiving phenytoin suspension, which requires that tube feedings be withheld for at least 1 hour before and after each dose.

Inaccuracy in estimating energy requirements is also a common cause of inadequate enteral feeding; inaccurate estimates can lead to complications associated with overfeeding and underfeeding in ICU patients.^33,35 Indirect calorimetry is considered more accurate than the HBE for determining the energy requirements of certain types of critically ill patients.¹⁹ However, as occurred in our study, technical and clinical limitations preclude using indirect calorimetry in some ICU patients, a situation that limits the usefulness of this method in the ICU.^23,29,30 Limitations include inaccurate measurement as a result of gas leaks or water vapor in the ventilator system, instability of delivered oxygen concentration, and fraction of inspired oxygen more than 0.60.³⁶ As a result of such limitations, the HBE is often considered a more practical and effective method than indirect calorimetry for estimating energy requirements in ICU patients.

Although not exactly equivalent, estimates of energy expenditure determined by using indirect calorimetry closely approximate daily energy requirements.³⁷ A surprising finding in our study was the lack of a difference between the mean 3-day energy intake and the measured energy requirements in the subgroup of 25 patients whose energy requirements were determined by using indirect calorimetry (Table 2). This finding conflicts with the results of a similar study by Kemper et al¹⁴ in which the enteral energy intake was significantly less than requirements determined by using indirect calorimetry. Although our sample size of 25 patients may have been too small to determine statistical significance, mean differences between measured REE and 3-day intake were small. When we compared patients in whom indirect calorimetry could be used with patients in whom it could not be used, we found no difference in illness severity scores, weight, or diagnosis.

When we compared energy requirements estimated by using the HBE with measured REEs in these 25 patients, the energy requirements were overestimated by a mean of 2042 kJ (488 kcal) when the HBE was used. This finding is similar to the results of other studies^33,38,39 of critically ill patients in which use of the HBE with stress factors resulted in an overestimation of energy requirements by 20% to 60%. It would seem that this finding may put patients at risk for the hazards of overfeeding. However, when we corrected the HBE estimates by 2042 kJ (488 kcal) for all 60 patients, the differences between their estimated energy requirements and their energy intake were still significant.

Estimates determined by using the HBE are common in clinical practice because they are easy to use and do not require the equipment and technical resources of indirect calorimetry. However, the sickest patients are the least able to tolerate inappropriate feeding regimens and may have better nutritional outcomes when their energy requirements are determined by using the most accurate technology available, such as indirect calorimetry. However, indirect calorimetry cannot be used in a considerable number of patients because of the limitations of the current technology.⁴⁰ Regardless of the method used to determine energy requirements, consistent delivery of adequate enteral feeding is an important goal in critically ill patients.

	Implications for Practice and Future Research

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Multiple interruptions of enteral tube feedings limit the adequacy of enteral intake in ICU patients receiving mechanical ventilation. Gastrointestinal intolerance is often the most common cause of inadequate delivery of enteral feedings early on. However, interruptions for tests and procedures become a more significant factor after patients have reached their goal rates for tube feeding. Tube feeding protocols can help standardize tube feeding practices and limit unnecessary interruptions in the feedings.^41,42 Continued development of such protocols is an important direction for future ICU research.

The relationship between optimal enteral intake and meaningful clinical outcomes is not yet known. Examination of the link between enteral feeding and decreases in the duration of mechanical ventilation, infection rates, and length of ICU stay is also a significant future research goal. Of note, the 2 methods used to determine nutritional requirements in a subsample in our study yielded different results related to adequacy of intake. This finding poses additional questions about the accuracy of methods commonly used to determine energy requirements.

	ACKNOWLEDGMENTS

 
We gratefully acknowledge the contributions of Bruce Wolfe, MD, for his assistance in developing the research protocol and James Canfield, Jr, BS/CCPT, and Terri Sexton, RRT, for their technical assistance. We also appreciate the support of the physicians, dietitians, respiratory therapists, and nurses in the intensive care units. This research was supported by a National Institute of Nursing Research, National Research Service, predoctoral award (1 F31 NR07707-01) and the Sigma Theta Tau, Alpha Eta chapter, Dissertation Research Award.

This research was supported by the Department of Veterans Affairs, Veterans Health Administration, Office of Academic Affairs, Predoctoral Nurse Fellowship. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs.

To purchase reprints, contact The InnoVision Group, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 809-2273 or (949) 362-2050 (ext 532); fax, (949) 362-2049; e-mail, reprints{at}aacn.org.

Commentary by Mary Jo Grap (see shaded boxes).

	REFERENCES

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Journal Club Article Discussion Points

When critically appraising this issue’s AJCC journal club article, "Nutritional Adequacy in Patients Receiving Mechanical Ventilation Who Are Fed Enterally," consider the questions and discussion points listed below.

Study Synopsis: Ensuring an adequate nutritional state in critically ill patients is an important component of care. This study examined the adequacy of enteral nutritional intake and factors that affected enteral feeding in 60 patients receiving mechanical ventilation in the intensive care unit (ICU). During 3 consecutive days, enteral calories received and reason and duration of interruptions in enteral feedings were recorded. The study results revealed a significant difference in caloric requirements and the mean calories received (P<0.0001). Most of the patients (68.3%) received less than 90% of their required calories. Reasons for enteral feeding interruptions included episodes of diarrhea, emesis, high residual volumes, feeding tube replacements, and interruptions for procedures, which was the factor that accounted for the most variation (45% of the variance in calories received).

1. Description of the Study
   • What was the purpose of the research?
     
   • Why is the problem significant to nursing care of ICU patients?
     
   
   
2. Literature Evaluation
   • What has previous research found concerning enteral feedings and caloric requirements of ICU patients?
     
   
   
3. Sample
   • What were study inclusion and exclusion criteria?
     
   • What was the rationale for enrolling patients into the study only after the tube feeding goal rate was achieved?
     
   
   
4. Methods and Design
   • Identify the nutritional data that were collected for each patient.
     
   • What would be the rationale for measuring caloric requirements by indirect calorimetry in a subgroup of patients?
     
   
   
5. Results
   • What were the findings of the research?
     
   • What percent of patients received adequate nutrition?
     
   • What were common reasons for tube feeding interruptions?
     
   • Do you see interruptions occurring in your clinical practice setting because of these reasons?
     
   
   
6. Clinical Significance
   • What are implications of the study for clinical nursing?
     
   • How might nursing care activities be altered to promote adequate nutritional intake in critically ill patients?
     
   
   

Information From the Authors: Colleen O’Leary-Kelley, PHD, RN, CCRN, CCNS, lead author of this journal club article, provided additional information about the study. She explained that the idea for the study arose from critical care nursing practice observations that patients did not always receive the amount of enteral feeding that was ordered. She shared, "Many factors (some related to the patient and others related to the ICU environment) impacted whether or not the required amount of enteral tube feeding each day was actually received. I found studies in the medical literature that were starting to look at this phenomenon. I wanted to examine the adequacy of enteral nutrition specifically in mechanically ventilated patients from a nursing perspective."

Data were collected each day using a data collection form. O’Leary-Kelley explained, "The daily total volume of enteral formula received was recorded directly from the patient’s flowsheet (hand-written or computerized). Study patients were clearly identified, and nurses were reminded to accurately chart hourly enteral intake. Nurses were also instructed to indicate the reason for feeding interruption on the flowsheet. There was a brightly colored laminated reminder card on the charting station of each study patient.

There were a number of reasons why feedings were interrupted in the study patients. O’Leary-Kelley explained, "The operative procedures that most often required interruption in enteral feedings were tracheostomy and percutaneous endoscopic gastrostomy. Scheduled tests and procedures that required interruption in feedings included computed tomography scans, transesophageal echocardiograms, ultrasound procedures, planned extubation, and post-extubation. Feedings were also held for bedside insertion of central lines, PICC lines, radial arterial lines, or while awaiting x-ray results to confirm tube placement; if the tube was placed late in the afternoon or evening, x-ray confirmation often did not occur until the next morning.

Several reasons for feeding interruptions were unexpected. "It was surprising to see that many patients frequently had feedings held for more than 24 hours at a time," O’Leary-Kelley said. "Also, nurses held feedings several times per day each time the patient was supine for even brief periods. Sometimes when the feeding was resumed after a long period of being held, it was resumed at a much lower rate than the goal rate despite the fact that the patient had been tolerating the goal rate infusion for several days."

Implications for Practice: According to the study results, many critically ill patients who are receiving enteral feedings do not receive their caloric requirements. The study results have direct implications for nursing practice because nurses are involved in administering and monitoring enteral feedings. O’Leary-Kelley added, "It is important to examine the enteral nutrition delivery practices observed in the ICU and for nurses to be aware of how much nutrition the patient receives each day, each shift. It is within the scope of our nursing practice to monitor nutritional intake, advocate for early feeding, and limit feeding interruptions." Additional research is needed to provide further data to promote evidence-based feeding practices for patients in the ICU.

Journal Club feature commentary is provided by Ruth Kleinpell.

This article has been cited by other articles:

				D. O'Meara, E. Mireles-Cabodevila, F. Frame, A. C. Hummell, J. Hammel, R. A. Dweik, and A. C. Arroliga Evaluation of Delivery of Enteral Nutrition in Critically Ill Patients Receiving Mechanical Ventilation Am. J. Crit. Care., January 1, 2008; 17(1): 53 - 61. [Abstract] [Full Text] [PDF]

				A. M. Bourgault, L. Ipe, J. Weaver, S. Swartz, and P. J. O'Dea Development of Evidence-Based Guidelines and Critical Care Nurses ' Knowledge of Enteral Feeding Crit. Care Nurse, August 1, 2007; 27(4): 17 - 29. [Full Text] [PDF]

				P. A. Higgins, B. J. Daly, A. R. Lipson, and S.-E. Guo Assessing Nutritional Status in Chronically Critically Ill Adult Patients Am. J. Crit. Care., March 1, 2006; 15(2): 166 - 176. [Abstract] [Full Text] [PDF]

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