Ileus
Intestinal paralysis – delay in coordinated bowel activity
Characterised by abdominal distension, decreased bowel sounds, delayed passage of flatus and faeces, accumulation of gas and fluids which may cause vomiting and nausea.
Most common reason for prolonged admission after urological abdominal surgery.
Large economic impact as well as patient discomfort and suffering, and need for parenteral nutrition.
Small bowel regains function in 24 hours
Stomach 24 – 48 hours
Colon 3 – 5 days
Pathophysiological mechanism hypotheses:
- Neurogenic – activation of a spinal reflex, exacerbated by sympathetic stress of surgery
- Pharmacologic – mu opioid receptors slow gut transit
- Inflammatory – direct manipulation of bowel, as well as innate and adaptive immune responses
Contributing factors to ileus:
- Direct bowel handling
- Prolonged operative time
- Open > lap
- Electrolyte disturbances
- Increased blood loss
Consider another underlying pathology if prolonged or unexpected ileus – intra-abdominal abscess, bowel leak, urine leak, urinoma, steroid withdrawal
Treatment:
- Nasogastric decompression
- Exclude bowel obstruction (CT)
- Ileus will have gas through entire bowel tract, and absence of transition point
- Correct electrolytes
- Avoid dehydration
- Minimise opiates
- Trial of prokinetics – metoclopramide
- Mobilisation
- Chewing gum
- TPN if anticipated 7+ days without oral nutrition
Prevention:
- Gum
- Early coffee
- Mu opioid receptor antagonists (alvimopan)
- Spinal / regional anaesthesia
- Minimise opiates
- Recreation of the peritoneum
- ERAS packages
Indications in general for nutritional support:
- BMI < 18.5
- Unintentional weight loss > 10 % in last 3-6 months
- BMI < 20 and > 5 % weight loss
- Surgical patients who have not had, or unlikely to have oral intake for more than 5 days
Benefits of enteral feeding:
- Cheaper
- Safer
- Psychological benefits
- Ongoing stimulation of barrier function of small intestine
- Less liver dysfunction, hyperglycaemia and septic complications
Enteral feeds contraindicated if proximal small bowel failure or fistula, complete bowel obstruction, shock, severe diarrhoea and severe pancreatitis.
TPN complications:
- Must be given into a central vein due to its high osmolality which irritates peripheral veins – usually PICC line – may have line complications (blockages, thrombosis, migration, dislodgement, infective and infective endocarditis)
- Hyperglycaemia or hypoglycaemia
- Fluid overload
- LFT derangement – biliary stasis, fat deposition in liver
- Hypertriglyceridaemia
- Hyperchloraemic acidosis
- Refeeding syndrome with critical electrolyte disturbances (magnesium, potassium, phosphate)
Technical points:
- Regular bloods including electrolytes and LFTs
- Sugar monitoring
- Managed largely by clinical dietitian
- Thiamine concurrently
- Start 20 mL/hr if dietitian not available
- Shouldn’t need to run fluids
Mixture of separate components – lipid emulsions, proteins, carbohydrates, dextrose, amino acids, vitamins, electrolytes, minerals, trace elements.