The effect of duodenojejunal alimentation on gastric pH and hormones in intensive care unit patients

Deep Vein Thrombosis and Stress Ulcer Prophylaxis in the Intensive Care Unit

Deep vein thrombosis (DVT) and stress gastric ulcers can be serious complications in patients admitted to the intensive care unit. This review discusses the risk factors associated with the development of DVT and stress-related mucosal disease (SRMD), evaluates the available literature on current options for DVT and stress ulcer prophylaxis, and examines the associated adverse effects and optimal duration of therapy.

Bench-to-bedside review: the gut as an endocrine organ in the critically ill

In health, hormones secreted from the gastrointestinal tract have an important role in regulating gastrointestinal motility, glucose metabolism and immune function. Recent studies in the critically ill have established that the secretion of a number of these hormones is abnormal, which probably contributes to disordered gastrointestinal and metabolic function. Furthermore, manipulation of endogenous secretion, physiological replacement and supra-physiological treatment (pharmacological dosing) of these hormones are likely to be novel therapeutic targets in this group. Fasting ghrelin concentrations are reduced in the early phase of critical illness, and exogenous ghrelin is a potential therapy that could be used to accelerate gastric emptying and/or stimulate appetite. Motilin agonists, such as erythromycin, are effective gastrokinetic drugs in the critically ill. Cholecystokinin and peptide YY concentrations are elevated in both the fasting and postprandial states, and are likely to contribute to slow gastric emptying. Accordingly, there is a rationale for the therapeutic use of their antagonists. So-called incretin therapies (glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide) warrant evaluation in the management of hyperglycaemia in the critically ill. Exogenous glucagon-like peptide-2 (or its analogues) may be a potential therapy because of its intestinotropic properties.

Use of enteral nutrition for stress ulcer prophylaxis

OBJECTIVE

To review the controversies involving the use of enteral nutrition support for stress ulcer prophylaxis and formulate recommendations.

DATA SOURCES

A MEDLINE search (1966-December 2000) was conducted using the MeSH of nutrition, ulcer, critical care, and acid to identify relevant articles. References of selected articles were reviewed, and relevant abstracts from critical care or gastrointestinal journals identified.

DATA EXTRACTION

Animal and human data from prospective studies, retrospective studies, and case series were evaluated for the effects of enteral nutrition on gastric pH, intramucosal pH, gastrointestinal blood flow, development of macroscopic mucosal erosions, and hemorrhage.

DATA SYNTHESIS

Intragastric administration of enteral nutrition has variable effects on gastric pH, enhances regional distribution of gastrointestinal blood flow, and may lower intramucosal pH. All substrates (carbohydrate, lipid, amino acid), when administered into the stomach, reduce the occurrence of mucosal erosions but do not entirely prevent their development. Few studies of stress ulcer prophylaxis regimens have reported use of enteral nutrition. Limited retrospective data suggest enteral nutrition support may be effective for preventing gastrointestinal hemorrhage, but the results of prospective studies are confounded by poor study design.

CONCLUSIONS

Definitive recommendations regarding the role of enteral nutrition for stress ulcer prophylaxis are not possible due to the lack of prospective, randomized studies. Therefore, the use of enteral nutrition as the only therapeutic agent for stress ulcer prophylaxis should be discouraged until definitive data are available. Initiation and discontinuation of pharmacologic stress ulcer prophylaxis should be independent of enteral nutrition.

Effectiveness and safety of a protocol for promotion of early intragastric feeding in critically ill children

OBJECTIVES: To investigate the feasibility, adequacy, and efficacy of early poststress intragastric feeding (EPIGF) in critically ill children. DESIGN: A prospective clinical study. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: Seventy-one consecutively enrolled critically ill children requiring prolonged mechanical ventilation. INTERVENTIONS: Full-strength intragastric tube feedings (Nutrison Pediatric, Standard) were initiated within 12 hrs of the study-entry event. Enteral feedings were advanced to a target volume of energy intake = 1/2, 1, 5/4, 6/4, and 6/4 of the predicted basal metabolic rate (PBMR) on days 1-5, respectively. MEASUREMENTS AND MAIN RESULTS: Nutritional status by the caloric intake, recommended dietary allowances, PBMR, predicted energy expenditure (PEE), anthropometry, and clinical indices were evaluated on days 1 and 5. Safety was assessed by the clinical course of disease, laboratory findings, and occurrence of complications. Success was determined by accomplishment of the PEE target. The early success rate was 94.4% and predicted late enteral feeding success accurately (p =.0001). Caloric intake approached PBMR the second day (43 +/- 1.7 kcal/kg/day vs. 43.2 +/- 1.1 kcal/kg/day) and PEE the fifth day (66.2 +/- 2.7 kcal/kg/day vs. 67.7 +/- 6.4 kcal/kg/day). Multivariate stepwise regression analysis showed that poor outcome and a high Therapeutic Intervention Scoring System score correlated with failure of EPIGF (p <.0001). Patients who succeeded EPIGF had significantly higher myocardial ejection (65% vs. 43%; p <.0001) or shortening fractions (34% vs. 20%; p =.0001) on day 1 than those who failed. Patients tolerated EPIGF well; 9.9% developed nosocomial pneumonia, 5.6% developed diarrhea, and 8.5% needed treatment with cisapride because of a delay of gastric emptying. The mortality rate (5.6%) was different between initial and final success and failure groups (p <.0001) and was lower than predicted by the admission severity scores (12% +/- 2%). CONCLUSIONS: This study showed that increases of caloric intake during the acute phase of a critical illness are well tolerated and may approach PBMR by the second day and PEE by the fourth day in critically ill children. Caloric intake lower than PBMR is associated with higher mortality and morbidity rates.

Intolerance to intragastric enteral nutrition in critically ill patients: complications and management

Compared with parenteral nutrition, early administration of enteral nutrition (EN) to critically ill patients improves clinical outcomes and reduces infection rates. Intragastric EN often is complicated by intolerance, as indicated by elevated volumes of aspirated gastric residuals. Conflicting data are available for the volume of residual that represents intolerance, but most clinicians use 150-200 ml to signify gastrointestinal motility dysfunction. Intolerance is associated with mortality. Data support an association between intragastric EN and aspiration pneumonia, but little information is available regarding the contributory effect of intolerance. Transpyloric migration of the feeding tube may facilitate tolerance but does not reduce the likelihood of aspiration pneumonia. Prokinetic agents (cisapride, erythromycin, metoclopramide) promote gastric emptying. Results of most studies are limited because patients did not receive or tolerated intragastric EN. Metoclopramide is the agent of choice for treating intolerance. Further studies are necessary before prokinetic drugs can be recommended for preventing intragastric EN-associated aspiration pneumonia.

Enteral nutrition in the critically ill patient: a critical review of the evidence

OBJECTIVE

To examine the relationship between enteral nutrition (EN) and infection in the critically ill.

SETTING

Computerized search of published research and review of relevant reference lists.

STUDY SELECTION

151 citations were reviewed and 39 articles met selection criteria. Primary studies were included if they evaluated EN in critically ill humans and its effect on infectious morbidity and mortality.

MEASUREMENTS AND RESULTS

Relevant data were abstracted on the timing and impact of EN on morbidity, the optimal route of administration, composition and pH of EN, and bacterial contamination of EN. The evidence from human studies that EN, particularly early EN, results in reduced septic morbidity as compared to parenteral nutrition is limited to small, unblinded studies with non-rigorous definitions of pneumonia. There is no evidence to support a preference of feeding into the stomach versus the small bowel. The addition of fish oil, arginine, glutamine and fiber to enteral feeds has a variable impact on survival in animal models; there are no trials in critically ill patients that demonstrate a reduction in infectious morbidity and mortality. Acidification of enteral nutrition results in decreased bacterial colonization of the stomach in critically ill patients. Bacterial contamination of enteral nutrition is an important source of infection.

CONCLUSIONS

Evidence from experimental data in critically ill patients suggests that enteral nutrition may have a favourable impact on gastrointestinal immunological function and infectious morbidity.

Placement of a duodenal feeding tube via gastrostoma with fiberoptic bronchoscope

We report a case of esophageal disruption that required a duodenal feeding tube. Because of collapse of the gastric outlet secondary to severe emaciation, several attempts to place a tube into the duodenum via gastrostoma had ended in failure. We finally were able to accomplish it with the aid of a fiberoptic bronchoscope and a Swan-Ganz catheter. The procedure is described and discussed.