Peripheral TPN complications
Solutions: Many solutions are commonly used. Electrolytes can be added to meet the patient’s needs. Patients who have renal insufficiency and are not receiving dialysis or who have liver failure require solutions with reduced protein content and a high percentage of essential amino acids.
- For patients with heart or kidney failure, volume (liquid) intake must be limited
- For patients with respiratory failure, a lipid emulsion must provide most of non-protein calories to minimize CO2 production by carbohydrate metabolism.
- Neonates require lower dextrose concentrations (17 to 18%).
Beginning TPN administration: Require CVP line Solution is started slowly at 50% of the calculated requirements, using 5% dextrose to make up the balance of fluid. Energy and nitrogen should be given simultaneously. The amount of regular insulin given (added directly to the TPN solution) depends on the blood glucose level; if the level is normal and the final solution contains the usual 25% dextrose concentration, the usual starting dose is 5 to 10 units of regular insulin
Complications: With close monitoring by a nutrition team, the complication rate may be < 5%..
1.Glucose abnormalities are common. a. Hyperglycemia can be avoided by monitoring blood glucose b. Hypoglycemia can be precipitated by suddenly discontinuing constant concentrated dextrose infusions. Treatment, depending on the degree of hypoglycemia, may consist of 50% dextrose IV or infusion of 5 or 10% dextrose for 24 h before resuming TPN via the central venous catheter.
2.Abnormalities of serum electrolytes and minerals Elevated BUN may reflect dehydration, which can be corrected by giving free water as 5% dextrose via a peripheral vein.
3. Volume overload
4. Metabolic bone disease, or bone demineralization (osteoporosis or osteomalacia), develops in some patients receiving TPN for > 3 mo. The mechanism is unknown
5. Adverse reactions to lipid emulsions (eg, dyspnea, cutaneous allergic reactions, nausea, headache, back pain, sweating, dizziness)
- are uncommon
- can occur if lipids are given at > 1.0 kcal/ kg/h.
6. Hepatic complications – liver dysfunction, painful hepatomegaly, and hyperammonemia. – Contributing factors probably include cholestasis and inflammation. Progressive fibrosis occasionally develops. Reducing protein delivery may help. Painful hepatomegaly suggests fat accumulation; carbohydrate delivery should be reduced. Hyperammonemia can develop in infants. Signs include lethargy, twitching, and generalized seizures. Correction consists of arginine
7.Gallbladder complications include cholelithiasis, gallbladder sludge, and cholecystitis. These complications can be caused or worsened by prolonged gallbladder stasis. Stimulating contraction by providing about 20 to 30% of calories as fat and stopping glucose infusion several hours a day is helpful. Oral or enteral intake also helps.