How should a patient with chronic atrial fibrillation on Eliquis (apixaban), presenting with small bowel obstruction and active bilious vomiting, be managed?

Morning Report: Chronic Atrial Fibrillation on Apixaban with Small Bowel Obstruction and Active Vomiting

Immediate Management Priority: Hold Apixaban and Assess Bleeding Risk

The most critical first step is to immediately discontinue apixaban due to active vomiting preventing oral absorption and the risk of intramural hemorrhage causing or worsening the bowel obstruction. 1, 2

Initial Assessment and Stabilization

Check the following immediately:

• INR/PT/PTT and complete blood count to assess coagulation status and detect occult bleeding 2
• Renal function (creatinine clearance) as apixaban is renally cleared and affects reversal strategies 3
• CT abdomen with IV contrast to identify the cause of obstruction and rule out intramural hematoma, which can occur with DOACs and present as bowel obstruction 1, 2
• CHA₂DS₂-VASc score to quantify stroke risk during anticoagulation interruption 3

Anticoagulation Management During Acute Phase

Apixaban must be held for the following reasons:

• Oral medications cannot be absorbed with active bilious vomiting 4
• Small bowel obstruction creates risk for intramural hemorrhage, which has been documented to cause intussusception and obstruction in patients on apixaban 1
• Anticoagulant-induced intramural jejunal hemorrhage can present identically to mechanical obstruction with circumferential wall thickening and luminal narrowing on CT 2

The mean duration of DOAC interruption for GI procedures is approximately 3.9 days, with resumption 1-2 days post-procedure depending on bleeding risk. 4

Small Bowel Obstruction Management

Follow the WSES 2021 guidelines for virgin abdomen SBO management: 3

• NPO status with nasogastric decompression for bilious vomiting
• Aggressive IV fluid resuscitation to correct volume depletion
• Serial abdominal exams every 4-6 hours looking specifically for peritoneal signs suggesting ischemia or perforation
• Water-soluble contrast study if no peritoneal signs, as 70% of adhesive SBOs resolve non-operatively 3

Surgical exploration is indicated if: 3

• Peritoneal signs develop
• CT shows closed-loop obstruction, pneumatosis, or portal venous gas
• Failure to improve after 48-72 hours of conservative management
• CT demonstrates intramural hematoma causing obstruction (requires resection) 1, 2

Atrial Fibrillation Rate Control During Acute Illness

Maintain rate control with IV agents since oral medications are not absorbed: 5

• IV metoprolol 2.5-5 mg every 6 hours as first-line for rate control (target heart rate <110 bpm at rest) 3, 5
• Add IV diltiazem infusion if beta-blocker alone is insufficient and LVEF >40% 5
• Add IV digoxin for combination therapy if dual agents needed, particularly if reduced LVEF 5
• Avoid amiodarone unless patient has heart failure with LVEF <40% and other agents fail 5

Bridging Anticoagulation Decision

Do NOT bridge with heparin in most cases. 3

• Bridging increases bleeding risk without reducing stroke risk in contemporary studies 3
• Calculate stroke risk during interruption: For CHA₂DS₂-VASc ≥2, the 30-day stroke risk during DOAC interruption for GI procedures is only 0.7% 4
• Only consider bridging if: CHA₂DS₂-VASc ≥6, mechanical valve (though apixaban is contraindicated), or recent stroke within 3 months 3

Resumption of Anticoagulation

Restart apixaban based on surgical intervention: 4

• If managed conservatively: Resume apixaban 1 day after symptoms resolve and patient tolerating oral intake 4
• If surgical resection performed: Resume apixaban 2 days post-operatively if hemostasis is secure and no high-risk bleeding features 4
• If intramural hematoma identified: Delay resumption 3-5 days and ensure hemoglobin is stable 2

Critical Pitfalls to Avoid

Common errors in this scenario:

• Continuing oral apixaban despite vomiting - the drug is not absorbed and provides no protection while increasing bleeding risk 4
• Routine bridging with heparin - this increases major bleeding to 2.5% without reducing thromboembolism 4
• Missing intramural hematoma on CT - look specifically for circumferential wall thickening with hyperdensity, which mimics mechanical obstruction 2
• Premature surgical exploration - 70% of SBOs resolve with conservative management unless peritoneal signs present 3
• Delaying anticoagulation resumption excessively - stroke risk accumulates daily, so resume as soon as bleeding risk permits 3, 4

Monitoring During Hospitalization

Daily assessment should include:

• Hemoglobin/hematocrit to detect occult bleeding 2
• Continuous telemetry to monitor ventricular rate and detect rhythm changes 3
• Abdominal exam for development of peritoneal signs 3
• Nasogastric output volume to assess resolution of obstruction 3

Expect resolution within 48-72 hours if managed conservatively; if no improvement, proceed to surgical exploration. 3