Research
Current Research
Feeding Practices of Severely Ill Intensive Care Unit Patients: An Evaluation of Energy Sources and Clinical Outcomes

https://doi.org/10.1016/j.jada.2006.12.012Get rights and content

Abstract

Objective

The quantity of nutrition that is provided to intensive care unit (ICU) patients has recently come under more scrutiny in relation to clinical outcomes. The primary objective of this study was to assess energy intake in severely ill ICU patients and to evaluate the relationship of energy intake with clinical outcomes.

Subjects/Settings

Seventy-seven adult surgery and medical ICU patients with length of ICU stay of at least 5 days.

Statistical Analyses Performed

Student’s t test and χ2 tests were used to examine ICU populations. To determine the relationship of patient variables to hospital length of stay and ICU, length of stay regression trees were calculated.

Results

Both groups were underfed with 50% of goal met in surgical ICU and 56% of goal met in medical ICU. Medical ICU patients received less propofol and significantly less dextrose-containing intravenous fluids when compared to surgical ICU patients (P=0.013). From regression analysis, approaching full nutrient requirements during ICU stay was associated with greater hospital length of stay and ICU length of stay. For combined groups, if % goal was ≥82%, the estimated average value for ICU length of stay was 24 days; whereas, if the % goal was <82%, the average ICU length of stay was 12 days. This relationship held true for hospital length of stay.

Conclusions

Medical and surgical ICU patients were insufficiently fed during their ICU stay when compared with registered dietitian recommendations. Medical ICU patients received earlier nutrition support, on average more enteral nutrition, with fewer kilocalories supplied from lipid-based sedatives and intravenous fluid relative to surgical ICU patients. Based upon length of stay, the data suggest that the most severely ill patient may not benefit from delivery of full nutrient needs in the ICU.

Section snippets

Materials and Methods

This investigation was a prospective cohort study conducted over a 5-month period. Adult (ie, ≥18 years of age) medical and surgical patients admitted to either the surgical or medical ICU were screened for eligibility. Guidelines for eligibility were primarily based on clinical recommendations from the American Society for Parenteral and Enteral Nutrition. These guidelines recommend that nutrition support be initiated when one anticipates that critically ill patients will be unable to meet

Patient Data

Demographic data collected included age, sex, pre-admission weight, and body mass index (BMI) calculations were made at the time of hospital admittance. Severity of disease was assessed using the Acute Physiology And Chronic Health Evaluation (APACHE II) calculated for ICU day 1 (10).

Nutritional Data and Calculations

There were no standing protocols in place that directed nutrition support in either of the two intensive care units; therefore, all decisions regarding feeding were made as a result of registered dietitian (RD) recommendations and ultimately made at the discretion of the patient’s attending physician. Patient energy requirements were determined by RDs and were based on a comprehensive nutritional evaluation as outlined in the institution’s nutrition standards of care for surgical and medical

Statistics

Descriptive analyses (mean, standard deviation, frequency as percentages) were calculated for the complete patient population and within the surgical and medical ICU populations. These groups were then compared using Student’s t test and χ2 tests. A P value of <0.05 was considered to be significant for these analyses. A regression tree analysis was used to determine the relationship among the various independent variables. The independent variables examined were: BMI; sex; age; percent goal;

Results

Eighty-one medical and surgical ICU patients were consecutively enrolled. Four patients were excluded due to incomplete data, leaving 77 subjects for analysis. Fourteen patients died before hospital discharge. The patients’ characteristics are reported in Table 1. With the exceptions of APACHE II scores and sex, patient characteristics did not differ between the two ICU groups. The surgical ICU had a significantly higher male population when compared with the medical ICU population, (χ2, P

Relationship of Energy Intake and Clinical Outcomes

Based on the classification and regression tree method, the best possible discriminating variable in our dataset was percent goal. No other independent variables were significantly correlated with either hospital length of stay or ICU length of stay. The relationship of energy intake to clinical outcomes is demonstrated by regression trees as shown in Figure 1, Figure 2, Figure 3, Figure 4. From Figure 1, if the value of the predictor variable, percent goal for the entire group, was 82% or

Discussion

This study examined the nutrition support of 77 very ill ICU patients with extensive ICU and hospital stays. Patients admitted to the medical ICU differed in the time of initiation, amount, and types of nutrition support when compared with patients admitted to the surgical ICU. Medical ICU patients received earlier nutrition support, on average more enteral nutrition, with fewer kilocalories being supplied from lipid-based sedatives and intravenous fluid support.

The levels of underfeeding in

Conclusions

In conclusion, medical and surgical ICU patients were insufficiently fed during their ICU stay when compared with RD recommendations. However, the data obtained suggest that the most severely ill patient may not benefit from delivery of full nutrient needs because patients receiving more than 81% of goal requirements had extended hospital and ICU stays when compared with patients who received less nutrition. Feeding practices differed significantly in medical and surgical ICU patients, with

M. E. Hise is an assistant professor, Department of Dietetics and Nutrition, B. J. Gajewski is an assistant professor, Schools of Allied Health and Nursing, M. Parkhurst is an assistant professor, and M. Moncure is an associate professor, all at The University of Kansas Medical Center, Kansas City.

References (25)

  • T.F. Muller et al.

    Immediate metabolic effects of different nutritional regimens in critically ill medical patients

    Intensive Care Med

    (1995)
  • J.F. Patino et al.

    Hypocaloric support in the critically ill

    World J Surg

    (1999)
  • Cited by (0)

    M. E. Hise is an assistant professor, Department of Dietetics and Nutrition, B. J. Gajewski is an assistant professor, Schools of Allied Health and Nursing, M. Parkhurst is an assistant professor, and M. Moncure is an associate professor, all at The University of Kansas Medical Center, Kansas City.

    K. Halterman is a clinical dietitian, The University of Kansas Hospital, Kansas City.

    J. C. Brown is a professor, Department of Molecular Biosciences, University of Kansas, Lawrence.

    View full text