Malnutrition in the critically ill

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Malnutrition in the Critically Ill Yi-Chia Huang, RD, PhD School of Nutrition and Institute of Nutritional Science, Chung-Shan Medical and Dental College, Taichung, Taiwan

After more than two decades of nutritional awareness, malnutrition is still a noticeable, common problem for hospitalized patients.1– 8 The prevalence of malnutrition varies from 30% to 50% in different studies according to the different criteria used: 50% of patients had abnormal nutritional status indices 1 wk after major surgery in the study by Hill et al.1; 38% of patients receiving ventilatory support appeared malnourished during their initial physical examinations at the Omaha Veterans Administration Medical Center2; 30% to 57% of hospitalized patients in National Taiwan University Hospital believed they had protein-calorie malnutrition4; 30% to 32% of hospitalized patients in Bridgeport Hospital were considered malnourished according to a group-based reference method5; and 43% of patients in the intensive care unit (ICU) were malnourished in the study by Giner et al.7 In a recently published study,8 my colleagues and I were startled to find that almost 100% of the mechanically ventilated, critically ill patients were malnourished at admission to the ICU of Taichung Veteran General Hospital, Taiwan, but the prevalence of malnutrition decreased to 94% with nutrition support 14 d later according to objective nutrition parameters in the Maastricht Index.9 The frequency of malnutrition in our study was higher than that reported by others.1–7 One reason for the difference might be that our patients received mechanicalventilation support and were from the ICU. Thus, the medical condition of our patients was probably more severe than that in other reports.1–7 The prevalence of malnutrition seems to be a serious worldwide problem for the critically ill. Hospital malnutrition has been hypothesized to be a factor contributing to organ failure.10 –12 Malnutrition can compromise the intestinal barrier function, which prevents bacteria from translocating to the blood and other organs, prolongs ventilator dependency as a result of not restoring respiratory muscle strength and endurance,6,13 lengthens hospital stay,14,15 and increases morbidity and/or mortality rates.16 Critically ill patients are particularly vulnerable to malnourishment because of the severity and complications of illness, the complexity of care in the ICU, the inability to express hunger and eat normally, and the physician’s inability to recognize nutritional risks. Ideally, early identification of nutritional status and provision of appropriate and aggressive nutrition support for critically ill patients might decrease ventilator dependence, ICU or hospital stay, and mortality rate. Larca et al.3 found that 8 of 14 mechanically ventilated patients responded well to nutrition support and could be weaned from the ventilators. Bassili et al.17 found that 54% of patients receiving insufficient nutrition support compared with 93% of the patients receiving sufficient nutritional support could be weaned from mechanical ventilators. Our study8 showed slight improvements in nutrition status in critically ill patients who had received nutritional support for 14 d. Nutritional support is essential in hospitalized patients, especially those who are critically ill. The advantages and disadvan-

Correspondence to: Yi-Chia Huang, RD, PhD, No. 110 Sec. 1 Chien-Kuo N. Road, Chung-Shan Medical and Dental College, School of Nutrition and Institute of Nutritional Science, Taichung 402, Taiwan. E-mail: ych@ mercury.csmc.edu.tw Nutrition 17:745–746, 2001 ©Elsevier Science Inc., 2001. Printed in the United States. All rights reserved.

tages of enteral, total parenteral, or combined nutritional support (enteral plus total parenteral) have been reviewed and discussed in many studies. Even so, determining the best method of nutritional support in critically ill patients is complex. However, enteral nutrition rather than total parenteral nutrition is more favorable because of its beneficial effects on the integrity of the intestinal mucosa, lower cost, and fewer risks of complications. Although providing early and appropriate nutrition intervention prevents malnutrition in critically ill patients, physicians often are unaware which patients are at nutritional risk on admission.18 More than 20 y ago, Butterworth19 reported that malnutrition was common and unrecognized by hospital physicians. Driver and LeBrun2 examined the nutrition management of patients requiring prolonged ventilatory assistance and found that only 3 of 26 patients received nutritional support sufficient to satisfy minimum metabolic needs. Roubenoff et al.18 reported that only 12.5% of their patients were correctly identified as malnourished by the house staff. Iatrogenic malnutrition in critically ill patients apparently exists in the hospital. Although clinical dietitians help physicians to assess nutritional status and manage nutritional therapies for hospitalized patients, critically ill patients depend almost entirely on doctors to satisfy most or all of their nutritional needs. Unfortunately, physicians usually do not receive sufficient training to recognize and prevent malnutrition. To solve this problem, Rooubenoff et al.18 suggested that educating physicians would effectively improve the nutrition care of patients without undue difficulty or expense. As a matter of fact, it is very important that medical students receive sufficient nutrition-related courses before starting their hospital practices. Different methods have been used to assess nutritional status in hospitalized patients, and there is no agreement as to which index best reflects the nutritional status in critically ill patients. No single nutritional measurement can be considered both sensitive and specific because non-nutritional responses to illness affect many nutrition indicators. When assessing the nutritional status for critically ill patients, it is necessary to combine different subjective measurements (i.e., subjective global assessment), objective measurements (i.e., anthropometry: weight, height, body mass index, and skinfold thickness; biochemistry: serum albumin, prealbumin, transferrin, and creatinine height index; and immune function: total lymphocyte count and delayed hypersensitivity), and multiparametric nutrition indices (Prognostic Nutrition Index20,21 and Maastricht Index9). To minimize the prevalence of malnutrition in the hospital, a simple and integrated nutrition screening should be part of the admission procedure. In addition, nutrition screening should be repeated regularly to monitor the changes in diagnosis or conditions that might put the patient at nutritional risk and the efficacy of nutritional support. Malnutrition is still a well-recognized nutritional problem for hospitalized patients, especially critically ill patients. If physicians, nurses, dietitians, and other staff can identify the nutrition status of patients and provide appropriate nutrition intervention early on, patient outcome would be improved and ventilator dependence, ICU or hospital stay, and mortality rate would decrease. 0899-9007/01/$20.00 PII S0899-9007(01)00625-6

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REFERENCES 1. Hill GL, Blackett RL, Pickford I, et al. Malnutrition in surgical patients: an unrecognized problem. Lancet 1977;1:689 2. Driver AG, LeBrun M. Iatrogenic malnutrition in patients receiving ventilatory support. JAMA 1980;244:2195 3. Larca L, Greenbaum DM. Effectiveness of intensive nutritional regimes in patients who fail to wean from mechanical ventilation. Crit Care Med 1982;10: 297 4. Chen WJ, Yu LJ, Mo ST, Chen KM. Prevalence of protein-calorie malnutrition in hospitalized patients. J Formos Med Assoc 1985;84:228 5. Spiekerman MA, Rudolph RA, Bernstein LH. Determination of malnutrition in hospitalized patients with the use of a group-based reference. Arch Pathol Lab Med 1993;117:184 6. Christman JW, McCain RW. A sensible approach to the nutritional support of mechanically ventilated critically ill patients. Intensive Care Med 1993;19:129 7. Giner M, Laviano A, Meguid MM, Gleason JR. In 1995 a correlation between malnutrition and poor outcome in critically ill patients still exists. Nutrition 1996;12:23 8. Huang YC, Yen CL, Cheng CH, Jih KS, Kan MN. Nutritional status of mechanically ventilated critically ill patients: comparison of different type of nutritional support. Clin Nutr 2000;19:101 9. de Jong PCM, Wesdorp RIC, Volovics A, et al. The value of objective measurements to select patients who are malnourished. Clin Nutr 1985;4:61

Nutrition Volume 17, Number 9, 2001 10. McMahon MM, Farnell MB, Murray MJ. Nutritional support of critically ill patients. Mayo Clin Proc 1993;68:911 11. Bower RH. Nutritional and metabolic support of critically ill patients. JPEN 1990;14:257s 12. Cerra FB. How nutrition intervention changes what getting sick means. JPEN 1990;14:164s 13. Rochester DF, Esau SA. Malnutrition and the respiratory system. Chest 1984; 85:411 14. Askanazi J, Starker PM, Olsson C, et al. Effect of immediate postoperative nutritional support on length of hospitalization. Ann Surg 1986;2:236 15. Garrel DR, Davignon I, Lopez D. Length of care in patients with severe burns with or without early enteral nutritional support. J Burn Care Rehab 1991;12:85 16. Mullen JL, Buzby GP, Matthews DC, Smale BF, Rosato EF. Reduction of operative morbidity and mortality by combined preoperative and postoperative nutritional support. Ann Surg 1980;192:604 17. Bassili HR, Deitel M. Effect of nutritional support on weaning patients off mechanical ventilators. JPEN 1981;5:161 18. Roubenoff R, Roubenoff RA, Preto J, Balke W. Malnutrition among hospitalized patients—a problem of physician awareness. Arch Internal Med 1987;147:1462 19. Butterworth CE. The skeleton in the hospital closet. Nutr Today 1974;9:4 20. Mullen JL, Buzby GP, Waldman MT, et al. Prediction of operative morbidity and mortality by pre-operative nutritional assessment. Surg Forum 1979;30:80 21. Buzby GP, Mullen JL, Matthews DC, Hobbs CL, Rosato EF. Prognostic nutritional index in gastrointestinal surgery. Am J Surg 1980;139:160