Development of a Standardized Parenteral Nutrition Protocol for the Obese Population

Abstract

Objectives: To determine if obese patients receiving parenteral nutrition (PN) require an increased amount of potassium, magnesium, and phosphorus electrolyte provisions compared to non-obese patients. Methods: The project design was an institutional review board-approved, retrospective, descriptive chart review. Electronic medical records and physical parenteral nutrition order cards were accessed to identify patients who met the inclusion and exclusion criteria of the study. The total amounts of potassium, phosphorous, and magnesium received by patients over the initial seven days of PN therapy were calculated. The Chi-squared and independent t-tests were utilized to evaluate the statistical significance for all nominal and interval data respectively. Results: 112 samples met the inclusion criteria of the study. There were 75 samples in the non-obese group (mean age=55.1 years, mean BMI=22 kg/m2, 53% female), and 37 samples in the obese group (mean age=57.1 years, mean BMI=33.8 kg/m2, 51% female). The daily average and seven-day totals of potassium, magnesium, and phosphorus did not significantly differ between the non-obese and obese groups (average daily potassium (P=0.6224), weekly total potassium (P=0.7551), average daily magnesium (P=0.8068), weekly total magnesium (P=0.3863), average daily phosphorus (P=0.9698), weekly total phosphorus (P=0.0603)). Conclusions: Potassium, magnesium, and phosphorus electrolyte provisions administered through PN over a week appear to be similar for both non-obese and obese patients. Our study results indicate that the same standard set for dosing initial PN electrolyte provisions in a non-obese patient may be applied to dosing similar provisions for an obese patient.