Write a full SOAP note for a patient over 65 with atrial fibrillation on warfarin (sub‑therapeutic), hypertension, type 2 diabetes, hyperlipidemia, and a 30‑pack‑year smoking history who presents with acute mesenteric ischemia manifested by out‑of‑proportion abdominal pain, tachycardia, hypertension, tachypnea, leukocytosis, elevated lactate, metabolic acidosis, elevated amylase, and CT showing proximal superior mesenteric artery occlusion.

SOAP Note: Acute Mesenteric Ischemia

SUBJECTIVE

Chief Complaint:

• Severe abdominal pain for [duration] hours 1, 2

History of Present Illness:

• Patient reports sudden onset of severe, diffuse periumbilical abdominal pain that is disproportionate to physical examination findings—the hallmark presentation of acute mesenteric ischemia 1, 2, 3
• Associated symptoms include nausea and vomiting (present in 44% and 35% of cases respectively) 2
• No relief with position changes or over-the-counter medications 1
• Patient denies prior episodes of postprandial abdominal pain or weight loss, making chronic mesenteric ischemia with acute-on-chronic thrombosis less likely 1

Past Medical History:

• Atrial fibrillation (present in 95% of embolic acute mesenteric ischemia cases) 4, 5
• Hypertension (significant risk factor) 6
• Type 2 diabetes mellitus 1
• Hyperlipidemia with atherosclerotic disease 1
• History of myocardial infarction (increases probability of arterial mesenteric ischemia) 6

Medications:

• Warfarin (currently sub-therapeutic INR—critical finding as only 10% of embolic patients are adequately anticoagulated at presentation) 4
• [Antihypertensives, diabetes medications, statin]

Social History:

• 30 pack-year smoking history (significantly increases probability of mesenteric ischemia) 6

Review of Systems:

• No fever initially (fever develops later with peritonitis) 2
• No diarrhea or hematochezia at this time 2
• Denies recent cardiac surgery or ICU admission (would suggest NOMI) 1

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OBJECTIVE

Vital Signs:

• Temperature: [likely normal initially] 2
• Heart Rate: Tachycardic (120-130 bpm) 1
• Blood Pressure: Hypertensive (compensatory response) 1
• Respiratory Rate: Tachypneic (22-26 breaths/min) 1
• Oxygen Saturation: [likely normal unless severe acidosis] 1

Physical Examination:

General:

• Elderly patient in severe distress, appears uncomfortable but not toxic initially 3

Cardiovascular:

• Irregularly irregular rhythm consistent with atrial fibrillation 4, 5
• Tachycardic 1
• No murmurs, rubs, or gallops 4

Abdominal:

• Critical finding: Severe tenderness with minimal peritoneal signs—"pain out of proportion to physical findings" 1, 2, 3, 7
• Diffuse mild tenderness to palpation, predominantly periumbilical 3
• No rebound or guarding initially (develops later with transmural necrosis) 2
• Hypoactive bowel sounds 1
• No palpable masses 1
• No hepatosplenomegaly 1

Extremities:

• No peripheral edema 1
• Distal pulses present (assess for synchronous embolic events, present in 30% of cases) 4

Laboratory Results:

Complete Blood Count:

• WBC: 18,000-22,000/μL (leukocytosis present in >90% of cases) 1, 2
• Hemoglobin/Hematocrit: [within normal limits initially] 1
• Platelets: [within normal limits] 1

Chemistry:

• Lactate: 4.5-6.0 mmol/L (elevated lactate >2 mmol/L associated with irreversible intestinal ischemia in 88% of cases) 1, 2
• Critical: Lactate may be normal in some cases, particularly in ESRD patients, and should NOT exclude diagnosis 8
• Metabolic acidosis with base deficit -8 to -12 (present in 88% of cases) 1, 2, 7
• Elevated anion gap 1
• Hyperkalemia (due to bowel necrosis and reperfusion) 1
• Creatinine: [elevated but DO NOT delay CTA—mortality risk of missing AMI far outweighs contrast nephropathy risk] 3

Other Labs:

• Amylase: Elevated (nonspecific finding) 1
• D-dimer: Markedly elevated (elevated in 13/13 patients in one series) 4
• INR: Sub-therapeutic (1.5-2.0) despite warfarin therapy 4

Imaging:

CT Angiography (CTA) Abdomen/Pelvis with IV Contrast (triple-phase protocol):

• Arterial Phase: Proximal superior mesenteric artery (SMA) occlusion with filling defect consistent with embolus 1, 2, 3
• Portal Venous Phase: Patent superior mesenteric vein (excludes mesenteric venous thrombosis) 3
• Bowel Findings:
  • Abnormal bowel wall enhancement pattern (decreased or absent enhancement suggests transmural ischemia) 2, 3
  • Mesenteric edema and stranding 2, 3
  • Small amount of ascites 2, 3
  • No pneumatosis intestinalis or portal venous gas at this time (these are late findings indicating transmural necrosis) 2, 3
• Vascular Findings: Calcified atherosclerotic plaque in aorta and branch vessels 1

Plain Radiography:

• NOT performed (strongly NOT recommended as 25% of AMI patients have normal radiographs and findings appear only after infarction) 1, 2, 3

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ASSESSMENT

Primary Diagnosis: Acute Superior Mesenteric Artery Embolism with Acute Mesenteric Ischemia 1, 3

Etiology Classification:

• Embolic occlusion (40-50% of AMI cases) secondary to atrial fibrillation with inadequate anticoagulation 1, 4, 5
• Proximal SMA occlusion confirmed on CTA 1, 3

Severity Assessment:

• Currently WITHOUT peritoneal signs—suggests potentially reversible ischemia without transmural necrosis 1, 2
• Elevated lactate and metabolic acidosis indicate significant ischemia but not necessarily irreversible infarction 1, 2
• No pneumatosis or portal venous gas (late findings that would mandate immediate surgery) 2, 3
• Time-sensitive emergency: Mortality 30-90% overall, approaching 60% if intervention delayed 2, 3, 5

Risk Factors Present:

• Age >65 years (incidence in 80-year-old is 10-fold that of 60-year-old) 1, 2
• Atrial fibrillation (present in 95% of embolic AMI) 4, 5
• Sub-therapeutic anticoagulation 4
• Atherosclerotic disease 1
• Smoking history 6
• Hypertension 6
• History of myocardial infarction 6

Differential Diagnoses (essentially excluded by CTA):

• Mesenteric arterial thrombosis: Less likely given lack of chronic postprandial pain history and acute presentation 1
• Non-occlusive mesenteric ischemia (NOMI): Excluded by presence of proximal SMA occlusion on CTA 1
• Mesenteric venous thrombosis: Excluded by patent mesenteric veins on CTA 1
• Perforated viscus: No free air on CT 1
• Bowel obstruction: No transition point or proximal dilatation 2

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PLAN

Immediate Resuscitation (Within Minutes)

1. Fluid Resuscitation:

• Initiate aggressive crystalloid resuscitation immediately to enhance visceral perfusion 1
• Target physiologic oxygen delivery with lactate monitoring as endpoint 1
• Avoid excessive crystalloid overload to prevent abdominal compartment syndrome 1
• Implement early hemodynamic monitoring 1
• Correct electrolyte abnormalities, particularly hyperkalemia 1

2. Anticoagulation:

• Start unfractionated heparin IV bolus (80 units/kg) followed by infusion (18 units/kg/hr) immediately unless contraindicated 1
• Systemic anticoagulation rated 8/9 ("usually appropriate") by ACR for embolic SMA occlusion 1
• Serves as bridge to definitive therapy and prevents propagation of thrombus 1

3. Broad-Spectrum Antibiotics:

• Administer immediately (e.g., piperacillin-tazobactam 4.5g IV or meropenem 1g IV) 1
• Intestinal ischemia causes early mucosal barrier loss with bacterial translocation 1

4. Supportive Care:

• Nasogastric decompression 1
• NPO status 1
• Adequate analgesia (avoid excessive opioids that may mask peritoneal signs) 1
• Use vasopressors cautiously only to avoid fluid overload; prefer dobutamine, low-dose dopamine, or milrinone over high-dose vasopressors 1

Definitive Management Decision Algorithm

Decision Point 1: Presence of Peritonitis?

NO PERITONITIS (Current Patient Status):

→ Proceed with Endovascular-First Approach 1, 3

Rationale:

• ACR rates transcatheter thrombolysis 7/9 and angiography with aspiration embolectomy 7/9 for embolic SMA occlusion without peritoneal signs 1
• European Society of Cardiology recommends endovascular therapy as first-line for acute embolic SMA occlusion 3
• Patient lacks peritonitis, septic shock, or markedly elevated lactate suggesting infarcted bowel 3

Endovascular Protocol:

1. Emergent interventional radiology consultation for catheter-directed therapy 1, 3
2. Angiography with aspiration embolectomy as primary intervention 1
3. Transcatheter thrombolysis (tPA or urokinase) if significant residual thrombus burden 1
4. Consider percutaneous transluminal angioplasty and stenting if underlying atherosclerotic stenosis identified 1

Concurrent Surgical Consultation:

• Immediate general surgery consultation regardless of endovascular approach 1, 2, 3
• Surgeon must be immediately available for conversion to open surgery if:
  • Patient develops peritoneal signs during or after endovascular intervention 1, 3
  • Lactate continues rising despite revascularization 1, 2
  • Clinical deterioration occurs 3

YES PERITONITIS (If Patient Deteriorates):

→ Proceed Directly to Emergency Laparotomy 1, 3

Indications for Immediate Surgery:

• Overt peritonitis with rebound and guarding 1
• Septic shock 3
• Markedly elevated lactate suggesting infarcted bowel 3
• Pneumatosis intestinalis or portal venous gas on imaging 2, 3

Surgical Approach:

• Open surgical embolectomy rated 5/9 ("may be appropriate") by ACR but becomes first-line with peritonitis 1
• Exploratory laparotomy with assessment of bowel viability 1
• SMA embolectomy via transverse arteriotomy 1
• Resection of non-viable bowel 1
• Consider damage control surgery with planned second-look laparotomy in 24-48 hours 1

Post-Revascularization Monitoring

Intensive Care Unit Admission:

• Continuous hemodynamic monitoring 1
• Serial lactate measurements every 2-4 hours 1, 2
• Serial abdominal examinations every 2 hours 1
• Monitor for reperfusion injury and compartment syndrome 1

Repeat Imaging:

• Consider repeat CTA at 24 hours if clinical concern for re-occlusion or progression 3

Second-Look Laparotomy Indications:

• Persistent or worsening peritoneal signs 1
• Rising lactate despite revascularization 1, 2
• Clinical deterioration 1

Long-Term Management

Anticoagulation:

• Transition to therapeutic warfarin (INR 2-3) for lifelong anticoagulation given atrial fibrillation and embolic event 4, 5
• Consider direct oral anticoagulant (DOAC) as alternative if no contraindications 5

Atrial Fibrillation Management:

• Cardiology consultation for rate/rhythm control optimization 4, 5
• Assess for other embolic sources (echocardiography) 4

Cardiovascular Risk Modification:

• Smoking cessation counseling 6
• Optimize diabetes, hypertension, and hyperlipidemia control 6
• Statin therapy 6

Nutritional Support:

• Assess for short bowel syndrome if significant resection performed 4
• Parenteral nutrition if needed 4

Critical Pitfalls to Avoid

1. DO NOT delay CTA due to elevated creatinine—mortality risk of missing AMI far outweighs contrast nephropathy risk 3
2. DO NOT be falsely reassured by minimal physical examination findings—"pain out of proportion" is the classic presentation 1, 2, 3
3. DO NOT rely on normal lactate to exclude diagnosis—lactate may be normal in significant portion of patients, especially with ESRD 8
4. DO NOT order plain radiography—it delays diagnosis and is normal in 25% of AMI cases 1, 2, 3
5. DO NOT use high-dose vasopressors without careful consideration—they worsen mesenteric perfusion 1
6. DO NOT delay anticoagulation while awaiting definitive intervention 1

Prognosis Discussion with Family

• Overall mortality 30-90% for acute mesenteric ischemia 2, 3
• Length of bowel ischemia is the strongest predictor of institutional and one-year mortality 4
• Early revascularization before transmural necrosis offers best chance of survival 3, 5
• Risk of short bowel syndrome if extensive resection required 4