Emergency Medicine · Year 3 · from Emergency Medicine

Case 3: Mesenteric Ischemia - The Pain Out of Proportion

Patient Demographics

  • Age: 76 years
  • Sex: Female
  • Occupation: Retired nurse

Chief Complaint

"Something is terribly wrong with my stomach."

History of Present Illness

A 76-year-old female presents with 6 hours of severe, diffuse abdominal pain. Pain was sudden in onset, initially crampy, now constant and severe (10/10). She describes the pain as "the worst of my life." She has had two episodes of bloody diarrhea. Notable history of atrial fibrillation - admits she stopped her warfarin 2 weeks ago due to cost.

Initial Assessment

ESI Level: 1 - Critically ill presentation

First Impression:

  • Appearance: Writhing in pain, appears acutely ill
  • Work of breathing: Tachypneic, shallow
  • Circulation: Pale, diaphoretic

Vital Signs:

  • Heart rate: 124 bpm, irregularly irregular
  • Blood pressure: 92/58 mmHg
  • Respiratory rate: 28 breaths/min
  • SpO2: 92% on room air
  • Temperature: 36.4C (hypothermic - concerning)

Primary Survey

Airway: Patent, moaning in pain Breathing: Tachypneic, decreased breath sounds at bases Circulation: Tachycardic (atrial fibrillation), hypotensive, cool extremities Disability: Alert but distressed, GCS 15 Exposure: Diaphoretic, no rashes

Critical Finding: Pain-Exam Discrepancy

Classic Finding:

  • Patient describes 10/10 pain
  • Abdominal exam: Soft, mildly tender, minimal guarding
  • "Pain out of proportion to exam" - hallmark of mesenteric ischemia

Resuscitation

Immediate Interventions:

  1. High-flow oxygen
  2. Two large-bore IVs, fluid resuscitation initiated
  3. Continuous cardiac monitoring
  4. Labs including lactate, coagulation studies
  5. Blood type and crossmatch
  6. Pain management: Fentanyl 50mcg IV
  7. Emergent CT angiography ordered

Secondary Survey

SAMPLE History:

  • Symptoms: Severe abdominal pain, bloody diarrhea, nausea
  • Allergies: None
  • Medications: Warfarin (stopped), metoprolol, digoxin, lisinopril
  • PMH: Atrial fibrillation, CHF, hypertension, prior MI
  • Last Meal: Breakfast, limited appetite recently
  • Events: Sudden onset severe pain

Risk Factors for Mesenteric Ischemia:

  • Atrial fibrillation (off anticoagulation) - embolic risk
  • CHF - low-flow state
  • Age >60
  • Atherosclerotic disease

Physical Examination:

Abdominal Exam:

  • Inspection: Non-distended, no surgical scars
  • Auscultation: Absent bowel sounds
  • Percussion: Mildly tympanitic
  • Palpation: Mild diffuse tenderness WITHOUT peritoneal signs (early)
  • Rectal: Gross blood, no melena

Cardiovascular:

  • Irregularly irregular rhythm
  • No murmurs
  • JVD present

Diagnostic Testing

Labs:

  • WBC: 22,400 with significant left shift
  • Hgb: 14.8, Hct: 45% (hemoconcentration)
  • Platelets: 198,000
  • BMP: Na 138, K 5.8, Cl 98, HCO3 14, BUN 38, Cr 2.1
  • Lactate: 8.6 mmol/L (markedly elevated)
  • ABG: pH 7.22, pCO2 28, HCO3 12 (metabolic acidosis with respiratory compensation)
  • INR: 1.1 (subtherapeutic - explains off warfarin)
  • Amylase/Lipase: Mildly elevated
  • LDH: 892 (elevated - ischemia marker)

Imaging:

CT Angiography Abdomen/Pelvis:

  • Abrupt occlusion of superior mesenteric artery (SMA) 3cm from origin
  • No flow in SMA branches
  • Bowel wall thickening of jejunum and ileum
  • Pneumatosis intestinalis present (air in bowel wall)
  • Portal venous gas
  • Findings consistent with acute mesenteric ischemia with bowel infarction

Diagnosis

Acute mesenteric ischemia - embolic occlusion of SMA with evidence of bowel infarction

Management

Immediate Resuscitation:

  • Aggressive IV fluids (balanced crystalloid)
  • Correct acidosis
  • Broad-spectrum antibiotics: Piperacillin-tazobactam 4.5g IV
  • Nasogastric tube decompression
  • Foley catheter

Emergent Surgical Consultation:

  • Findings discussed with vascular surgery and general surgery
  • Patient taken emergently to OR

Operative Management:

  • SMA embolectomy with Fogarty catheter
  • Assessment of bowel viability
  • Resection of 80cm of non-viable jejunum and ileum
  • Primary anastomosis
  • Planned second-look laparotomy in 24-48 hours

Disposition

  • Surgical ICU
  • Vasopressors required post-operatively
  • Anticoagulation (heparin) initiated post-op
  • Second-look laparotomy at 36 hours - remaining bowel viable
  • Prolonged ICU course, eventual discharge to rehab
  • Lifelong anticoagulation for atrial fibrillation

Teaching Points

  1. Pain out of proportion: Classic finding; severe pain with benign-appearing abdomen suggests mesenteric ischemia
  2. High clinical suspicion required: Mortality >50% if diagnosis delayed; early recognition is key
  3. Risk factors: Atrial fibrillation, recent MI, CHF, atherosclerosis, hypercoagulable states
  4. Laboratory clues: Elevated lactate, metabolic acidosis, leukocytosis, elevated LDH
  5. CT angiography: Gold standard for diagnosis; identify occlusion and signs of infarction
  6. Pneumatosis and portal venous gas: Late findings indicating bowel necrosis; associated with poor prognosis
  7. Treatment: Emergent revascularization + bowel resection if infarction; second-look laparotomy often needed
  8. Anticoagulation compliance: This case illustrates consequences of stopping anticoagulation

Clinical Image

Image Description: Axial CT image demonstrating pneumatosis intestinalis (air within the bowel wall, arrows) and portal venous gas, findings consistent with advanced mesenteric ischemia with bowel infarction.

Attribution: Image from Radiopaedia.org, Case courtesy of Dr. Matt Skalski. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/mesenteric-ischaemia-with-pneumatosis-intestinalis

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