Total parenteral nutrition in the surgical patient: a meta-analysis

Objective: To examine the relationship between total parenteral nutrition(T PN) and complication and death rates in surgical patients. Data sources: A computer search of published research on MEDLINE, personal files and a revi ew of relevant reference lists. Study selection: A review of 237 titles, ab stracts or papers. Primary studies were included if they were randomized cl inical trials of surgical patients that evaluated the effect of TPN (compar ed to no TPN or standard care) on complication and death rates. Studies com paring TPN to enteral nutrition (EN) were excluded. Data extraction: Releva nt data were abstracted on the methodology and outcomes of primary studies. Data were independently abstracted in duplicate. Data synthesis: There wer e 27 randomized trials in surgical patients that compared the use of TPN to standard care (usual oral diet plus intravenous dextrose). When the result s of these trials were aggregated, there was no effect on mortality (risk r atio = 0.97, 95% confidence intervals, 0.76 to 1.24). There R ere fewer maj or complications in patients M ho received TPN, although there was signific ant heterogeneity in the overall estimate (risk ratio = 0.81, 95% CI, 0.65 to 1.01). Because of this significant heterogeneity, several a priori hypot heses were examined. Studies that included only malnourished patients demon strated a trend to a reduction in complication rates but no difference in d eath rate when compared with studies of patients who H ere not malnourished . Studies published in 1988 or earlier and studies with a lower methods sco re were associated with a significant reduction in complication rates and a trend to a reduction in death rate when compared with studies published af ter 1988 and studies with a higher methods score. There was no difference i n studies that provided Lipids as a component of TPN when compared with stu dies that did not. Studies that initiated TPN preoperatively demonstrated a trend to a reduction in complication rates but no difference in death rare when compared with studies that initiated TPN postoperatively. Conclusions : TPN does not influence the death rate of surgical patients. It may reduce the complication rate, especially in malnourished patients, but study resu lts are influenced by methodologic quality and year of publication.