Complications of Parenteral Nutrition Quiz

Parenteral Nutrition

• Massive bowel resection, ileus, and severe pancreatitis are contraindications for enteral nutrition
• Routes of parenteral nutrition include:
  • Peripheral access: PICC, short wrist cannula
  • Central access: subclavian, internal jugular, external jugular

Complications of Parenteral Nutrition

• Related to nutrient deficiency:
  • Hypomagnesemia, hypoglycemia, hypocalcemia, hypophosphatemia
  • Chronic deficiency syndromes: fatty acids, zinc, minerals, and trace elements
• Related to overfeeding:
  • Hyperglycemia, hyperosmolar dehydration, hepatic steatosis, hypercapnia, increased sympathetic activity, fluid retention, electrolyte disorders
  • Excess fat, excess amino acids, and proteins
• Related to sepsis:
  • Catheter-related and systemic sepsis
• Related to line complications:
  • Pneumothorax, vascular damage, air embolism, thoracic duct injury, cardiac injury, hydro mediastinum, long-term occlusion, venous thrombosis, acidosis, hypercalcemia

Vitamins and Minerals

• Vitamin B12 needs in small intestinal resection
• Fat-soluble vitamins (A, D, K, E) absorption reduced in steatorrhea and bile reduction
• Minerals (Na+, K+, Ca++, PO4) need monitoring and replacement in diarrheal disease
• Trace elements (Zn, Fe, Cu, Mg) important in hypermetabolic state

Enteral Nutrition

• Methods of delivery:
  • Oral feeding in patients who can drink
  • Tube feeding: NGT, fine-bore feeding tube, surgical PEG tube, post-pyloric feeding (nasojejunal tube, jejunostomy tube)
• Indications:
  • Protein-energy malnutrition with inadequate oral intake
  • Dysphagia
  • Major trauma
  • Inflammatory bowel disease
  • Enhance adaptation for massive enterectomy
• Contraindications:
  • SBO
  • Severe diarrhea
  • Proximal small intestinal fistula
  • Severe pancreatitis

Complications of Tube Feeding

• Tube-related:
  • Malposition
  • Displacement
  • Blockage
  • Leakage
  • Local erosion
• Gastrointestinal:
  • Diarrhea
  • Nausea and vomiting
  • Abdominal cramps
  • Aspiration
  • Constipation
• Metabolic or biochemical:
  • Electrolyte imbalance
  • Vitamin and mineral deficiencies
  • Drug interactions
• Infective:
  • Exogenous (hand contamination)
  • Endogenous (from patient)

Total Parenteral Nutrition (TPN)

• Provides all nutrients intravenously, bypassing the GIT
• Indications:
  • Proximal intestinal fistula
  • Inflammatory bowel disease (pre-op)

Nutrition and Malnutrition

• Malnutrition is common in surgical patients (30% with gastrointestinal diseases, up to 60% with prolonged hospital stay)
• Aim of nutritional support: identify patients at risk and minimize complications
• Causes of malnutrition:
  • Pre-operative: starvation, poverty, dysphagia, chronic vomiting
  • Post-operative: transient and delayed return to normal diet
  • Hypercatabolic state: severe sepsis, severe trauma
• Metabolic response to starvation:
  • Low insulin
  • High glucagon
  • Hepatic glycogenolysis
  • Protein catabolism
  • Hepatic gluconeogenesis
  • Lipolysis
  • Adaptive ketogenesis
  • Reduction in resting energy expenditure (REE)

Nutritional Assessment

• Body weight and anthropometric techniques:
  • Unintentional weight loss >10% in preceding 6 months indicates poor prognosis
  • Body mass index (BMI): <18.5 indicates nutritional impairment, <15 indicates significant hospital mortality
• Clinical techniques:
  • History of weight loss
  • Dietary intake
  • GI symptoms
  • Examination: muscle wasting, loss of subcutaneous fat, edema, alopecia
• Laboratory techniques:
  • No single reliable method to measure malnutrition
  • Albumin <30gm/l indicates poor nutrition
  • Defective immune function: decreased lymphocyte count

Nutritional Requirements

• Energy: 20-30 kcal/kg/day for stable patients
• Carbohydrates: 2gm/kg/day for brain and RBCs
• Fat: 4-5gm/kg/day
• Protein: 0.1-1.5gm/kg/day
• Fluids: calculated based on age and weight
• Vitamins: water-soluble vitamins (A, C) required post-op