What are the complications of Total Parenteral Nutrition (TPN)?

Complications of Total Parenteral Nutrition (TPN)

Total parenteral nutrition (TPN) is associated with numerous serious complications affecting multiple organ systems, including catheter-related infections, metabolic disturbances, and liver disease, all of which can significantly impact morbidity and mortality.

Catheter-Related Complications

• Central line-associated bloodstream infections (CLABSIs) are the most common and serious complications of TPN, causing significant morbidity and mortality, especially in patients with intestinal failure 1
• The reported incidence of catheter-related bloodstream infections (CRBSI) ranges from 3.8-11.3 infections per 1000 catheter days in pediatric patients and between 0.34-3.94 episodes per catheter year in home TPN patients 1
• Major pathogens causing catheter infections include Gram-positive coagulase-negative (30-40%) or positive (7.7-15%) staphylococci, Gram-negative bacteria (30-40%), fungi (4.6-6%), or polymicrobial flora (12%) 1
• Venous thrombosis is another significant catheter-related complication that can lead to loss of vascular access sites, which may eventually necessitate intestinal transplantation 1
• Progressively compromised vascular access (loss of all but two major venous access points) is considered a complication severe enough to warrant consideration for intestinal transplantation 1

Metabolic Complications

• Metabolic complications include hyperglycemia, hypoglycemia, hyperlipidemia, hypercapnia, refeeding syndrome, and acid-base disturbances 2
• Electrolyte imbalances are particularly challenging in patients with renal failure and require daily monitoring of sodium, potassium, and phosphorus 3
• Refeeding syndrome can occur in malnourished patients starting TPN, characterized by severe electrolyte shifts and potentially life-threatening complications 3, 2
• Overfeeding is a common cause of metabolic complications and should be avoided through proper assessment of nutritional requirements and close monitoring 2

Hepatobiliary Complications

• TPN-associated liver disease is a serious complication that can progress to end-stage liver disease requiring combined intestinal-liver transplantation 1
• Liver complications range from mild biochemical abnormalities to severe conditions including steatosis, steatonecrosis, cholestasis, fibrosis, and cirrhosis 4, 5
• Risk factors for TPN-associated liver disease include:
  • Pure soybean-based lipid emulsions (should be avoided in cholestasis) 1
  • Excessive dextrose administration and fatty acid deficiency 1
  • Lack of enteral nutrition 1, 4
• Strategies to reduce liver complications include:
  • Maximizing enteral intake as tolerated 1
  • Cycling TPN infusion (recommended as soon as metabolic and fluid status allows) 1
  • Using mixed lipid emulsions rather than pure soybean-based formulations 1
  • Considering ursodeoxycholic acid in the presence of cholestasis 1

Bone Disease

• Metabolic bone disease is a recognized complication of long-term TPN 2, 5
• Regular assessment of bone mineralization is recommended for patients on long-term TPN 1
• Regular measurements of urinary calcium, plasma calcium, phosphorus, parathyroid hormone, 25-OH vitamin D concentrations, and serum alkaline phosphatase activity should be performed in patients on home TPN 1

Other Complications

• Aluminum toxicity can occur with long-term TPN, requiring ingredients with the lowest amount of aluminum for preparation of parenteral nutrition solutions 1
• Manganese toxicity has been reported with long-term TPN administration 2
• Technical complications related to catheter placement and maintenance 5
• Fluid overload can occur, particularly in patients with cancer and peritoneal carcinomatosis, requiring restriction of intravenous water supply 1

Prevention and Management Strategies

• A nutrition support team (NST) is recommended to minimize complications through adherence to management protocols, particularly catheter care 1
• The core NST should include a physician, nutrition nurse specialist, senior dietician, and senior clinical pharmacist 1
• Proper validation of TPN formulations by a licensed manufacturer or qualified institution is essential 1
• Multi-layer bags impermeable to oxygen and light protection for both bags and administration sets are recommended 1
• TPN should be administered via a central line with its tip positioned in the superior vena cava or inferior vena cava 1
• Cycling TPN to overnight infusion should be implemented as soon as metabolically feasible 1
• TPN should be used for the shortest period possible, with oral or enteral feeding initiated as soon as clinically feasible 2, 6

When to Consider Intestinal Transplantation

• Intestinal transplantation should be considered when life-threatening complications of TPN occur, including:
  • Liver disease (portal hypertension, bridging hepatic fibrosis, or cirrhosis) due to TPN that is irreversible 1
  • Loss of vascular access for TPN (loss of all but two major venous access points) 1
  • Recurrent or life-threatening central line sepsis (including fungal sepsis) 1
  • Inability to maintain adequate hydration/nutrition despite TPN 1