Chinese Society of Critical Care Medicine-CSCCM 10th Anniversary

讲座摘要

ICU中的营养问题 NUTRITIONAL ISSUES IN ICU

Jean REIGNIER

Address correspondence to

Dr Jean REIGNIER

Service de reanimation polyvalente

Centre Hospitalier Départemental

85000 La Roche sur Yon

E-mail: jean.reignier@chd-vendee.fr

Abstract

Nutrition is a key component of the care of critically ill patients.

Underfeeding has been associated with delayed wound healing, increased risks of nosocomial infections and delayed weaning from mechanical ventilation.

Guidelines state that enteral nutrition (EN) should be preferred to the parenteral route.

EN has documented positive effects on gut mucosa integrity, immune function, infection rates, glycemic control, and survival.

Guidelines also state that EN should be instituted early (within 24-48 hours) after admission in ICU.

Indeed, early EN has been associated with higher energy intake, lower infection rates, shorter length of stay, and increased survival, compared to delayed EN.

However, despite guidelines and scientific evidence, studies at the bedside showed that the parenteral route is preferred to EN by many clinicians.

And, when used, EN is frequently delayed or frequently interrupted leading to a discrepancy between what patients need and what they actually receive.

The main cause of this discrepancy between guidelines and clinical practice is that many critically ill patients have an impaired gastrointestinal motility with poor gastric emptying, which carries a risk of regurgitation and nosocomial pneumonia.

However, treatments and protocols should be used to improve the delivery of early EN.

Erythromycin has gastric prokinetic effects and has been demonstrated to reduce the rate of vomiting when administered to an unselected population of critically ill patients fed early and to improve tolerance to early EN in patients with previously elevated residual gastric volume (RGV).

Preventive strategies should also be implemented in patients at particular risk of intolerance to EN.

For instance, the high rate of intolerance demonstrated in highly hypoxemic patients turned in the prone position can be reduced with a protocol including prophylactic Erythromycin, elevation of the head of the bed and increased flow rate of EN.

Monitoring of the RGV is a leading cause of interruption of EN and subsequent underfeeding that should be abandoned.

Indeed, the technique of measurement has never been standardized and a cutoff value never determined.

Moreover, compared to patients with RGV monitoring, patients without RGV monitoring during early enteral feeding received more EN without experiencing increased rates of vomiting or ventilator associated pneumonia.

Another means to improve the delivery of early EN is to start immediately at the rate required by patients’ caloric needs.

Compared to slow increase, maximum flow rate at the onset of EN has been associated with increased calories received by the patients without detrimental effect on tolerance to EN and without increased risk of nosocomial pneumonia.

Last, it has been shown that implementation of protocols was associated with improved delivery of early EN with better adequacy to patients’ needs.

第二届中法危重病医学研讨会暨上海重症医学论坛（2009年12月中国上海）