Systemic approach to parenteral nutrition in the ICU

The nutrition support clinician must understand and evaluate all aspects of parenteral nutrition (PN) to maximize benefits while avoiding unfavorable consequences for the patients in the intensive care unit. The various aspects in caring for the PN patient include appropriate patient selection, intravenous access choice and maintenance, and individualized PN prescription to meet each patient's unique macronutrient and micronutrient requirements. Once the PN prescription has been determined, the clinician should also be familiar with the compounding process to ensure the final solution is safe for infusion. PN is one of the most complex solutions prepared in the pharmacy with numerous ingredients. Due to the number of components in the PN solution, physicochemical incompatibilities are a common and serious problem, thus specific compounding sequence and guidelines must be followed to avoid precipitation of mixed products. Once the PN solution is ready for infusion, protocols should be in place to assure safe administration. Close monitoring for tolerance of electrolytes and macronutrients, as well as glucose control is necessary initially; whereas monitoring of specific micronutrients is crucial in long-term PN usage. A standardized process for ordering, preparing, administering and monitoring PN is recommended to assure patient safety.