How should I manage an 84-year-old patient with three days of no defecation and new onset emesis?

Management of an 84-Year-Old with 3 Days of Constipation and Vomiting

This patient requires immediate evaluation for bowel obstruction, which is a surgical emergency that accounts for 15% of acute abdominal pain admissions and carries significant mortality risk in elderly patients. 1

Immediate Assessment Priorities

Rapidly assess for red flag signs indicating complete or complicated obstruction:

• Bilious vomiting suggests mechanical obstruction 2
• Peritoneal signs (rigidity, rebound tenderness) indicate possible perforation or ischemia 1
• Hemodynamic instability (hypotension, tachycardia) suggests advanced disease 3
• Fever and diffuse abdominal pain raise concern for strangulation 3

Check vital signs immediately - hypotension and fever are particularly concerning for bowel ischemia or perforation in this age group 1, 3

Diagnostic Workup

Obtain CT scan of the abdomen/pelvis with IV contrast - this is the most reliable diagnostic method and can differentiate mechanical obstruction from ileus 3. Plain radiographs cannot exclude obstruction and should not be relied upon 3.

Order basic laboratory tests:

• Complete metabolic panel to identify electrolyte abnormalities (hypokalemia, hypercalcemia, hypomagnesemia can cause ileus) 4, 5
• Complete blood count (leukocytosis suggests ischemia or perforation) 1
• Lactate level (elevated in bowel ischemia) 1

Initial Management

Start aggressive IV fluid resuscitation with normal saline immediately - elderly patients with vomiting and no bowel movements for 3 days are severely volume depleted 2, 6

Correct electrolyte abnormalities promptly, particularly potassium, sodium, and magnesium, as these directly impair intestinal motility and worsen the clinical picture 2, 6, 4

Make patient NPO (nothing by mouth) and consider nasogastric tube placement for gastric decompression, especially if significant abdominal distension or ongoing vomiting is present 3

Antiemetic Management

Administer ondansetron 8 mg IV or sublingual as first-line antiemetic - this has superior efficacy and fewer side effects compared to other agents 2, 6

Use scheduled dosing every 8 hours rather than PRN to prevent further vomiting episodes 2, 1

If vomiting persists after 24 hours, add metoclopramide 10 mg IV every 6-8 hours (from a different drug class with dopamine antagonist mechanism) 2, 1. However, avoid metoclopramide if mechanical obstruction is confirmed, as it increases peristalsis against an obstruction 1.

For refractory vomiting, add dexamethasone 8-12 mg IV 2, 1

Critical Decision Point: Mechanical vs Functional Obstruction

If CT confirms mechanical small bowel obstruction:

• Consult surgery immediately 3
• Complete obstruction or signs of strangulation require urgent operative intervention 1, 3
• Partial obstruction without strangulation may be managed conservatively initially with close monitoring 3

If imaging shows colonic pseudo-obstruction (Ogilvie's syndrome):

• This functional obstruction is common in elderly, immobilized patients with electrolyte disturbances 7
• Treat with neostigmine 2 mg IV over 3-5 minutes (after correcting electrolytes and ruling out mechanical obstruction) 4, 7
• Consider colonoscopic decompression if pharmacologic therapy fails 4

If findings suggest adynamic ileus:

• Continue supportive care with IV fluids and electrolyte correction 4
• Discontinue any medications that impair motility (opioids, anticholinergics, calcium channel blockers) 4
• Ileus typically resolves with conservative management once precipitating factors are addressed 4

Common Pitfalls to Avoid

Do not rely on oral medications - the oral route is not feasible with ongoing vomiting; use IV or rectal routes 2, 1

Do not use PRN antiemetic dosing - scheduled around-the-clock administration is essential for symptom control 2, 1

Do not delay surgical consultation - in an 84-year-old with 3 days of obstipation and vomiting, the risk of complicated obstruction with ischemia or perforation is substantial and mortality increases dramatically with delayed intervention 1, 3

Do not give prokinetic agents (metoclopramide) if mechanical obstruction is present - this can worsen the obstruction and increase perforation risk 1

Do not overlook hypercalcemia - this is a rare but important cause of paralytic ileus that requires specific treatment 5

Disposition

Admit to hospital with surgical service evaluation regardless of whether obstruction is mechanical or functional, given the patient's age, duration of symptoms, and risk of complications 3