Parenteral Nutrition

Abstract

Parenteral nutrition has advanced significantly since it was first developed by Shohl and colleagues in 1939. Numerous early problems included allergic reactions to heterogeneous protein hydrosylates, side effects from intravenous fat preparations, and sclerosing of peripheral veins due to hyperos­molar infusions. Over time, protein hydrosylates were replaced by amino acid preparations, the development of Intralipid allowed greater caloric density to be delivered isotonically, and the ability to deliver nutrients via central venous access proved to be invaluable. When used properly, parenteral nutrition can provide substantial benefit to pediatric surgical patients, but complications and comorbidities are still ­commonly encountered and need to be considered very carefully prior to instituting intravenous nutritional therapy.

Appendices

Summary Points

Indications for initiating parenteral nutrition should consider both the age of the patient and anticipated duration of parenteral nutrition needs.

In general, limited enteral nutrition for a short period of time (7–10 days) is preferred over a short course of parenteral nutrition due to fewer complications.

PICC lines are ideal for parenteral nutrition.

Patients requiring long-term treatment are best served by placing a single lumen tunneled catheter at a time remote from infection.

Bacterial catheter infections can usually be treated with antibiotic therapy; fungal infections require removal of central lines.

IFALD is more common in premature infants, and may be associated with overfeeding and recurrent infections.

Limiting parenteral lipids to less than 1 mg/kg 1 day a week or providing all lipids enterally may slow the progression of liver disease, yet mandates checking essential fatty acid levels by monitoring the triene: tetraene ratio.

A triene: tetraene ratio >0.4 indicates an essential fatty acid deficiency, which precedes clinical manifestations.

Intestinal failure patients are best managed by a multidisciplinary approach.

Editor’s Comment

There is no doubt that advances in the science of parenteral nutrition have saved countless lives; however until the mystery of parenteral nutrition-associated cholestasis is solved, it will continue to be simply a bridge to enteral nutrition. As a result, the goal for every patient receiving parenteral nutrition is to get off of it as soon as possible. Peripheral nutrition rarely provides enough nutrition to make a real difference and tends to require daily replacement of peripheral intravenous catheters, which can be torturous for the patient. It is incumbent on the surgeon or interventionalist who places central venous catheters in patients who will need long-term parenteral nutrition to do everything possible to preserve the central veins. This means placing only the smallest single-lumen catheter needed to meet the child’s needs, having protocols and support staff available to help families avoid catheter dislodgement and line infections, and monitoring patients closely for catheter-associated vein thrombosis so that the catheter can be removed and treatment started early. Some of these patients will benefit from a work up for a hypercoagulable state.

Every year the literature is replete with reports of new breakthroughs in the understanding of parenteral nutrition-associated liver disease, but none have provided the definitive solution to the problem. The latest and perhaps most promising are taurine and omega-3 fatty acids, each of which, so far at least, appears to be protective against cholestasis. The best preventative measure, of course, is to transition to enteral nutrition as soon as possible.

PICC lines have revolutionized the care of patients who need parenteral nutrition for up to several months at a time, but the risk of complications and catheter-associated blood stream infection remains relatively high. Perhaps the most significant advantage is that it has lowered the threshold for surgeons to begin (and patients to accept) the initiation of parenteral nutrition in borderline situations, especially in the postoperative period. While patients with prolonged ileus or multiple procedures in the past might have been reluctant to consider placement of a central venous catheter, they and their surgeons are now probably less inclined to fear placement of a PICC line at an earlier stage in their postoperative recovery, when it can make the difference between healing and the risk of multiple complications.