Managing Feeding Intolerance in Respiratory Failure Patients

Introduction

Critical illness is often associated with catabolism. Consequently, providing nutritional support to those who cannot eat is essential to prevent malnutrition in the critical care setting.1 When considering nutrition support in the critical care unit (ICU), certain comorbidities should be taken into careful consideration when formulating an enteral feeding plan. For example, pre-existing liver or renal dysfunction is an important aspect when contemplating nutrition support and can alter the choice of enteral nutrition formulas selected for delivery. The management of critically ill patients with a history of alcohol abuse is complex and nutrition plays a vital part, where malnutrition and other clinical complications may prove detrimental, with adverse effects on mortality.2

 

Although nutrition support is a lifesaving therapy in the intensive care setting, adequate delivery of nutrition is frequently prevented by a myriad of treatments i.e. treatments and complications common in this patient group. For example, diarrhoea is a frequently reported complication of enteral feeding, affecting up to 12 to 25 per cent of patients, even in the absence of gastrointestinal-dysfunction.3,4 Patients with acute respiratory failure appear to be particularly at risk, with up to 50 per cent developing diarrhoea during their ICU stay. Smith et al. 3 found that up to 63 per cent of patients receiving mechanical ventilation (MV) who had higher feeding infusion rates (>50ml/h) had diarrhoea, and for a longer duration. It has been reported that the motility of the upper gastrointestinal tract in patients receiving MV is severely impaired; contractile activity is completely lost in the stomach and diminished to a lesser degree in the duodenum.6 Furthermore, the safety of enteral feeding in severe respiratory failure patients, in particular those on extracorporeal membrane oxygenation, has been questioned.7 Extracorporeal membrane oxygenation (ECMO) has been used increasingly in the past three decades in the support of patients with severe cardiopulmonary failure unresponsive to conventional therapies. Concerns for the negative effects of enteral nutrition in patients receiving ECMO has led to withholding enteral nutrition in this patient group in many ICU centres.7

 

These aspects of nutritional support in the ICU are examined in this brief report, which highlights a case study of an alcoholic female who was transferred for ECMO due to severe hypoxaemia.

Discussion

This study highlights the benefits of using a peptide formula, whey protein and 70% MCT, in the management of feeding intolerance in a patient receiving MV. A key finding is that within 24 hours of initiating the peptide formula, stool output had halved and frequency reduced by the fourth day. This is a significant clinical result, as among clinical complications, diarrhoea is the most distressing to patients and nursing staff. Many factors have been implicated in the aetiology of diarrhoea; however, the cause is largely unknown and probably multifactorial.5 Recently, luminal excess of bile acids has been offered as a possible cause for diarrhoea.16 This was confirmed by animal studies showing that prolonged starvation causes gut atrophy, including the terminal ileum.17

 

In human studies, Hernandez, et al.18 performed duodenal biopsies in 15 critically ill patients after four days of fasting and confirmed the presence of mucosal atrophy. Similarly, in a DeMeo, et al.16 study, 18 of 19 ICU patients developed diarrhoea when enteral feeding was started after five days of fasting. In this case report, that can be an explanation for the success of peptide feed in an alcoholic patient. In alcoholic liver disease, a study showed that 48 per cent of daily caloric intake was derived from alcohol in this patient group.19 In this case report, the high MCT formula content can explain the success of this nutrition approach. The MCT fat can be absorbed directly across the small intestine in the absence of bile salts and lipase, hence it is believed to be beneficial in feeding malabsorptions.20

 

Therefore, a peptide formula with a high MCT content and whey protein can be successful in patients who would otherwise require parenteral nutrition because of feeding intolerance.

 

Another significant result was that patient only lost five per cent body weight, despite 33 days on ICU, compared to admission weight. A stool output reduction <350ml/day within two days of introducing the peptide feed was instrumental in maintaining adequate energy balance and minimising catabolism. It can be concluded that suboptimal management of enteral nutrition could be the most common cause of feeding intolerance, therefore, education of nutrition staff can have the potential to reduce the misuse of parenteral nutrition. Additionally, the Society of Critical Care Medicine, and the American Society for Parenteral and Enteral Nutrition, recommend the use of peptide semi-elemental formula for patients with persistent diarrhoea (Grade E).21

Conclusion

The evidence supporting peptide feed in diarrhoea are not conclusive. It must also be noted that, overall, there is not enough data on the use of peptide feeds. With the luxury of increasing availability of different enteral nutrition formulas, differing in their protein and fat content and ranging from monomeric to polymeric preparations, comes a complexity in the decision-making process with regards to nutrition support in critical illness.

 

Dietitians must try different formulations, where a polymeric formula has failed, before considering the parenteral route. This case illustrates the potential merits of critical reasoning, despite scarce evidence, to the nutrition management of feeding intolerance in the critical care setting.

References

1. Martin CM, et al. Multicentre, cluster-randomized clinical trial of algorithms for critical-care enteral and parenteral therapy (ACCEPT). CMAJ 2004; 170: 197-204.
2. Mackie IJ. Swann DG. Cook B. One year outcome of intensive care patients with decompensated alcoholic liver disease. Br J Anasth 2006; 97(4): 496-98.
3. Smith CE, et al. Diarrhoea associated with tube feeding in mechanically ventilated critically ill patients. Nurs Res 1990; 39: 148-152.
4. Cataldi-Betcher EL, et al. Complications occurring during enteral nutrition support a prospective study. J Parenter Enteral Nutr 1983; 7: 546-552.
5. Ringel AF, Jameson GL, Foster ES. Diarrhoea in the intensive care patient. Crit Care Clin 1995; 11: 465-477.
6. Dive A, et al. Gastroduodenal motility in mechanically ventilated critically iII patients: a manometric study. Crit Care Med 1994; 17: 755-758. 7. Rokyta R. et al. Enteral nutrition and hepatosplanchnic region in critically ill patients - friends or foes? Physio Res. 2003; 52: 31-37.
8. Detsky AS, McLaghlln JR, Baker JP. What is subjective global assessment of nutritional status? J Parenter Enteral Nutr 1987; 11: 8-13.
9. Kreymann KG, et al. ESPEN guidelines on enteral nutrition: Intensive care. Clin Nutr. 2006; 25: 210-223.
10. Nguyen NQ, et al. Erythromycin is more effective than metoclopramide in the treatment of feed intolerance in critical illness. Crit Care Med 2007; 35: 483-489.
11. Begmark S. Immunonutrition: Role of biosurfactants. fibre and probiotic bacteria. Nutrition 1998; 14: 585-594.
12. De Aguilar-Nascimento JE. Prado Silveira BR. Dock-Nasciment DB. Early enteral nutrition with whey protein or casein in elderly patients with acute ischemic stroke: a double-blind randomized trial. Nutrition 2011; 27(4): 440-4. Epub 2010.
13. Wierdsma NJ, et al. Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: as prospective observational pilot study. Crit Care. 2011; 15: R264.
14. Channick R. Curley FJ, lrwin RS. Indications of rectal tube use in critically ill patients. J Intensive Care Med 1988; 3: 321-326.
15. Heyland DK. Cahill N, Day AG. Optimal amount of calories for critically iII patients: Depends on how you slice the cake! Critical Care Medicine 2011; 39: 2619-2626.
16. DeMeo M, et al. Beneficial effect of a bile acid resin binder on enteral feeding induced diarrhoea. Am J Gastroenterology 1998; 93: 967-971 .
17. Lo CW, Walker WA. Changes in the gastrointestinal tract during enteral and parenteral feeding. Nutr Rev 1989; 47; 193-198.
18. Hernandez G, et al. Gut mucosal atrophy after a short enteral fasting period in critically ill patients. J Crit Care 1999; 14: 73-77.
19. Sarin SK, et al. Dietary and nutritional abnormalities in alcoholic liver disease: A comparison with chronic alcoholics without liver disease. Am J Gastroenterol 1997; 92(5): 777-783.
20. Parrish CR. Elemental and semi-elemental formulas: are they superior to polymeric formulas? Pract Gastroent 2005: 59-72.
21. McClave SA, et al. Guidelines for the provision and assessment of nutrition support therapy in the adult critically iII patient: Society of Critical Care Medicine (SCCM) and American Society