Nutrition in ICU

University of Modena, Modena, and Ospedale Villa Pineta, Pavullo (MO), Italy 

Pulmonary and Respiratory Intensive Care Unit-University Hospital Pisa, Italy and Pulmonary Rehabilitation and Weaning Center, Auxilium Vitae, Volterra (PI), Italy 

Therefore, nutritional assessment and management is an important therapeutic option among patients with chronic respiratory diseases (10), especially those requiring prolonged mechanical ventilation (PMV) in ICU (11). Table 1 emphasizes the effects of malnutrition on the respiratory function in patients in ICU. However, specific nutritional deficiencies such as hypophosphatemia (12) have been associated with respiratory failure and impaired lipid synthesis (13) and may cause an abnormal increase in the fat mass. 

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Cerra FB, Benitez MR, Blackburn GL, et al. AppUed nutrition in ICU patients A consensus statement of the American College of Chest Physicians. Chest 1997 111 769-778. 

In a retrospective, medical record/data-base review of the use of parenteral nutrition in 286 adults, 14 (5%) developed new-onset candidemia (1.6 episodes per 1000 hospital days). Of the subgroup of 177 patients who were treated in ICU, 11 (6%) developed candidemia (2.4 episodes per 1000 ICU days) most had severe infections [40 ]. The duration of parenteral nutrition was significantly longer in those who developed candidemia (median 17 versus 8 days) and hospital mortality was increased (36% versus 16%). 

Glutamine deficiency occurs in critically ill patients, especially burn patients, as a result of increased protein turnover in the hypercatabolic state (56,57). Low levels of Glutamine on admission are associated with shock and increased hospital mortality and are more common in older persons (58). Glutamine supplementation in ICU patients was reviewed by the Italian Society of Enteral and Parenteral Nutrition (SINPE) (59), which noted that increased plasma glutamine levels were associated with improved outcomes in ICU patients. Other antioxidants such as parenteral selenium are also of interest in ICU patients (60). 

Bonnici A, Ruiner CE, St-Laurent L, Hornstein D. An interaction between levo-dopa and enteral nutrition resulting in neuroleptic malignant-like syndrome and prolonged ICU stay. Ann Pharmacother 2010 44(9) 1504-7. 

Coleman H, Chew E (2007) Nutritional supplementation in age-related macular degeneration. CurrOpin Ophthalmol 18 220-223. doi 10.1097/ICU.0b013e32814a586b Mares-Perlman JA, Fisher AI, Klein R, Block G, Millen AE, Wright JD (2001) Lutein and zeaxanthin in the diet and serum and their relation to age-related maculopathy in the third national health and nutrition examination survey. Am J Epidemiol 153 424—432 Sasamoto Y, Gomi F, Sawa M, Tsujikawa M, Hamasaki T (2010) Macular pigment optical density in central serous chorioretinopathy. Invest Ophthalmol Vis Sci 51 5219-5225. doi 10.1167/iovs.09-4881... 

Nutritional support is especially important for patients who have spent several weeks or months in an ICU. Malnutrition is commonly associated with prolonged hospitalization (18) and it is aggravated by diminished swallowing, profound dyspnea, and depression. Therefore, all patients are evaluated at baseline for nutritional supplementation. For those who are unable to sustain an adequate oral intake, enteral and sometimes parenteral nutrition may be necessary. For other patients, the advice of the dietitian is invaluable in managing obesity or weight loss and maintaining a healthy weight. 

Adequate nutritional support in the ICU is very important and guidelines for these nutritional interventions have been published (47,48). The interdisciplinary team formulates the nutritional care plan to include monitoring, the most appropriate route of administration, the method of nutritional access, the duration of therapy, and educational objectives. Figure 1 shows the algorithm for the decision to initiate specialized nutritional support. A variety of delivery routes and nutritional formulation components are available. 

Malnutrition is still an underestimated problem in the ICU among patients with chronic respiratory failure, and, therefore, a nutritional assessment is an important part of the management of patients requiring ventilation (90). Appropriate nutrition makes a valuable contribution to outcomes in the ICU and whether feeding is oral, enteral, or parenteral, it should be organized to provide the best caloric and metabolic daily intake. 

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