Audit of parenteral nutrition: standard parenteral nutrition regimens -feast or famine?

Abstract

Background: Adequate nutrition of patients at a surgical unit is of great importance since both over- and undernutrition can lead to serious morbidity and even mortality. Surgical patients are frequently unable to meet nutritional needs by the enteral route and the use of SPN regimens is a common practice. Compared with patient-specific prescriptions, SPN solutions require fewer nutritional calculations, are less expensive, more convenient and offer greater biochemical stability. However, the accuracy and consistency with which these regimens meet patients??? nutritional requirements remain unclear and are undefined in the literature. To examine whether patients at a surgical unit are adequately fed with SPN regimens, 13 surgical patients were prospectively followed- up and a comparison was made between the nutrients prescribed with the SPN solutions and the nutrients calculated individually for each patient. Mat erial and Methods: The exact amounts of macronutrients calculated and prescribed with the SPN regimens were collected. To calculate individualised nutritional requirement the Schofield equation was used with adjustment for activity and stress. Elia???s recommendation was used for protein requirements. Fat/carbohydrate calories were calculated. Anthropometry was used to estimate patients??? nutritional status. Prescribed and calculated energy, nitrogen, fat and carbohydrate were compared using Wilcoxon signed rank tests. Spearman???s rho correlations were calculated. Results : Statistically significant difference was found between fat (sig.=0,001), carbohydrate (sig.=0,05) and energy (sig.=0,03) provided by SPN regimens and the ones calculated. No statistically significant difference was found between delivered and calculated nitrogen. ConclusionS: For short-term feeding, the potential benefits of SPN regimens may outweigh the risks associated with carbohydrate deficit and fat and energy excess. However, for longer-term feeding these risks may become clinically significant. Some improvement of the quality of feeding can be established by calculating nutritional requirements and by assessing the patients??? nutritional status before commencing PN.