Objective: Nutritional support as enteral or parenteral nutrition (PN) is used in hospitalized patients to reduce catabolism. This study compares outcomes of early enteral nutrition (EN) with early PN in hospitalized patients.
Design: The authors conducted a metaanalysis of randomized, controlled trials (RCT) comparing early EN with PN. Studies on immunonutrition were excluded. Studies were categorized as medical, surgical, or trauma.
Patients: RCTs of early EN/PN were identified by search of 1) MEDLINE (1966-2002), 2) published abstracts from scientific meetings, and 3) bibliographies of relevant articles.
Measurements and main results: Thirty RCTs (ten medical, 11 surgical, and nine trauma) compared early EN with PN. The effect of nutrition type on hospital mortality and complication rates was reported as risk difference (RD%) and hospital length of stay (LOS) as mean weighted difference (MWD days). Missing data, by outcomes, varied from 20% to 63%. As a result of heterogeneity of treatment effects, the DerSimonian-Laird random-effects estimator was reported. There was no differential treatment effect of nutrition type on hospital mortality for all patients (0.6%, p = .4) and subgroups. PN was associated with increases in infective complications (7.9%, p = .001), catheter-related blood stream infections (3.5%, p = .003), noninfective complications (4.9%, p = .04), and hospital LOS (1.2 days, p = .004). There was no effect of nutrition type on technical complications (4.1%, p = .2). EN was associated with a significant increase in diarrheal episodes (8.7%, p = .001). Publication bias was not demonstrated. Metaanalytic regression analysis did not demonstrate any effect of age, time to initiate treatment, and average albumin on mortality estimates. Cumulative metaanalysis showed no change in the mortality estimates with time.
Conclusion: There was no mortality effect with the type of nutritional supplementation. Although early EN significantly reduced complication rates, this needs to be interpreted in the light of missing data and heterogeneity. The enthusiasm that early EN, as compared with early PN, would reduce mortality appears misplaced.