Postoperative day 2 confusion after emergency laparotomy
A 71-year-old man underwent emergency laparotomy and small bowel resection for adhesional obstruction 48 hours ago. Comorbidities: type 2 diabetes on metformin and gliclazide, hypertension, and mild cognitive impairment. Current medications: morphine patient-controlled analgesia, cefuroxime and metronidazole, enoxaparin, and omeprazole. Overnight he becomes agitated, pulling at his nasogastric tube, and is disoriented to place and time. Observations: temperature 38.3°C, pulse 112/min, blood pressure 102/58 mmHg, respiratory rate 24/min, oxygen saturation 93% on 2 L nasal cannula, urine output 20 mL/hour over the last 3 hours. Capillary glucose 4.1 mmol/L. Abdomen distended and tender with reduced bowel sounds; the wound looks clean. White cell count 17.2 ×10⁹/L, creatinine 168 µmol/L (baseline 92), CRP 190 mg/L, lactate 2.8 mmol/L.
1. Construct a differential diagnosis for the delirium and prioritize investigations and immediate actions.
Read the worked answer
Delirium in a postoperative elderly patient is multifactorial, but the combination of fever, tachycardia, hypotension, oliguria, rising creatinine, rising CRP, and abdominal tenderness makes an intra-abdominal septic source the leading concern. The differential includes:
- Anastomotic leak or intra-abdominal abscess
- Aspiration pneumonia or hospital-acquired pneumonia
- Urinary tract infection, especially if catheterized
- Line or wound infection
- Hypoglycemia (excluded at 4.1 mmol/L, but recheck)
- Opioid toxicity, anticholinergic effects, or drug interactions
- Alcohol or benzodiazepine withdrawal if relevant
- Electrolyte disturbance, dehydration, or renal failure
- Myocardial infarction or arrhythmia
- Pulmonary embolism
Immediate actions: ABC assessment, give oxygen to maintain saturation, obtain intravenous access, take blood cultures and urine culture before antibiotics, and start broad-spectrum antibiotics active against gram-negative and anaerobic organisms after surgical review. Order an urgent CT abdomen and pelvis with contrast to look for leak, collection, or ischemia, plus a chest radiograph, ECG, arterial blood gas, full blood count, coagulation, and repeat lactate. Fluid-resuscitate for the oliguria and hypotension with balanced crystalloid, insert a urinary catheter to monitor output, and consider early critical care involvement.
Stop the patient-controlled morphine and review all medications for deliriogenic agents. Hold metformin and gliclazide because of acute kidney injury and hypoglycemia risk, and start a variable-rate insulin infusion if glucose rises. Use non-pharmacological delirium measures: orientation, glasses and hearing aids, sleep hygiene, and family presence. Reserve antipsychotics for severe agitation that endangers the patient and use the lowest dose for the shortest time.
2. The CT shows a 6 cm fluid collection adjacent to the anastomosis with no free gas. The patient remains hypotensive after 2 L of crystalloid. What is your next step and how do you decide between drainage and reoperation?
Read the worked answer
This is a contained anastomotic leak with an abscess and evolving sepsis. The choice depends on the patient's physiology, the anatomy of the collection, and the availability of expertise.
If the patient is stable enough for transfer and the collection is accessible, percutaneous image-guided drainage is preferred as a first step: it avoids a second laparotomy, allows culture-directed antibiotics, and can be repeated. Send the drained fluid for culture and sensitivity. Continue broad-spectrum antibiotics and reassess within 24-48 hours; failure to improve, increasing lactate, worsening organ dysfunction, or signs of generalized peritonitis mandate laparotomy.
If the patient remains hypotensive despite adequate fluid resuscitation, or has diffuse peritonitis, or the collection is not accessible, proceed to laparotomy for peritoneal lavage, drainage, and consideration of a defunctioning stoma or revision of the anastomosis depending on the state of the bowel and tissues.
In parallel, escalate to critical care for vasopressor support and invasive monitoring, correct the acute kidney injury with careful fluid balance, and involve senior surgery and anesthesia in the decision. Discuss the goals of care with the family, given the frailty and cognitive impairment, and document the discussion. Reassess the need for the nasogastric tube and ensure adequate nutrition, including parenteral nutrition if enteral feeding is not possible for a prolonged period.