In short, the consequences of malnutrition in critical illness are as follows:
- Poor wound healing
- Impaired immune function and increased risk of sepsis
- Muscle wasting due to protein catabolism:
- Decreased ventilatory drive
- Weakness complicating separation from the ventilator
- Increased duration of ventilation, with associated complications (eg. increased risk of VAP)
- Weakness complicating physiotherapy and mobilisation
- Exposure to the complications of immobility, eg. DVT
- Cardiomyopathy as a consequence of atrophy
- Mucosal atropthy and diminished barrier function of the gut
- Apathy and depression
- Increased duration of ICU stay
- Increased in-hospital mortality
The disadvantages of poor nutrition are amplified in the hypercatabolic state of criticall illness. In the ICU, in most circumstances one would rather be fat than skinny. Question 27 from the second paper of 2013 asked about the effects of malnutrition on the critically ill patient. In short, it affects every system adversely, and the objective of this summary is to bring this complicated topic together into an easily remembered point-form list.
There are numerous excellent sources for this. The 1984 article by Rochester and Esau is an excellent primer on the effects of malnutrition on the respiratory system. Unless otherwise noted, the information below comes from this article.
http://www.criticalcarenutrition.com/ is an excellent resource for all things nutrition-related.
Berger, Mette M., and Claude Pichard. "Best timing for energy provision during critical illness." Crit Care 16.2 (2012): 215.
Dhaliwal, Rupinder, et al. "The Canadian Critical Care Nutrition Guidelines in 2013 An Update on Current Recommendations and Implementation Strategies."Nutrition in Clinical Practice 29.1 (2014): 29-43.
de Souza Menezes, Fernanda, Heitor Pons Leite, and Paulo Cesar Koch Nogueira. "Malnutrition as an independent predictor of clinical outcome in critically ill children." Nutrition 28.3 (2012): 267-270.
Norman, Kristina, et al. "Prognostic impact of disease-related malnutrition."Clinical nutrition 27.1 (2008): 5-15.
Kirkland, Lisa L. "Extent and Impact of Malnutrition in Critically Ill Patients." Diet and Nutrition in Critical Care (2015): 265-278.
de Andrade, F. Moreira, et al. "Nutrition and tracheal morphology; does malnutrition lead to characteristics of premature aging?." Nutr Hosp 27.6 (2012): 2146-2147.
Ghignone, Marco, and Luc Quintin. "Malnutrition and respiratory function." International anesthesiology clinics 24.1 (1986): 65-74.
Ezzell, Lisa, and Gordon L. Jensen. "Malnutrition in chronic obstructive pulmonary disease." The American journal of clinical nutrition 72.6 (2000): 1415-1416.
Bender, Darija Vranešić, et al. "Malnutrition in ICU." Croatian International Symposium on Intensive Care Medicine. Vol. 61. No. 2. 2012.
Laaban, Jean-Pierre, et al. "Nutritional status of patients with chronic obstructive pulmonary disease and acute respiratory failure." CHEST Journal 103.5 (1993): 1362-1368.
Fiaccadori, Enrico, et al. "Prevalence and Clinical Outcome Associated with Preexisting Malnutrition in Acute Renal Failure A Prospective Cohort Study." Journal of the American Society of Nephrology 10.3 (1999): 581-593.
Rochester, Dudley F., and Sharon A. Esau. "Malnutrition and the respiratory system." CHEST Journal 85.3 (1984): 411-415.
Moriguchi, Satoru, Saburo Sone, and Yasuo Kishino. "Changes of alveolar macrophages in protein-deficient rats." The Journal of nutrition 113.1 (1983): 40-46.
Sahebjami, Hamid, and John A. Wirman. "Emphysema-like Changes in the Lungs of Starved Rats 1–3." American Review of Respiratory Disease 124.5 (1981): 619-624.
Huang, Y. C., et al. "Nutritional status of mechanically ventilated critically ill patients: comparison of different types of nutritional support." Clinical Nutrition 19.2 (2000): 101-107.
Viart, P. "Hemodynamic findings in servere protein-calorie malnutrition." The American journal of clinical nutrition 30.3 (1977): 334-348.
Alden, PETER B., et al. "Left ventricular function in malnutrition." American Journal of Physiology-Heart and Circulatory Physiology 253.2 (1987): H380-H387.
Soukoulis, Victor, et al. "Micronutrient deficiencies: an unmet need in heart failure." Journal of the American College of Cardiology 54.18 (2009): 1660-1673.
Becker, Dorothy J. "The endocrine responses to protein calorie malnutrition." Annual review of nutrition 3.1 (1983): 187-212.
Hakim, Raymond M., and Nathan Levin. "Malnutrition in hemodialysis patients." American journal of kidney diseases 21.2 (1993): 125-137.