What is the appropriate management for an elderly male presenting with left lower quadrant pain and hypotension?

Management of Elderly Male with Left Lower Quadrant Pain and Hypotension

This patient requires immediate resuscitation, urgent CT abdomen/pelvis with IV contrast, and preparation for potential emergency surgery given the hypotension suggesting complicated diverticulitis with possible perforation or septic shock. 1

Immediate Resuscitation and Stabilization

• Initiate aggressive fluid resuscitation with crystalloids to restore blood pressure above 90 mmHg systolic, as hypotension (BP 100/58) in the setting of left lower quadrant pain suggests septic shock from complicated diverticulitis 1, 2
• Obtain immediate laboratory studies including complete blood count with differential, C-reactive protein (CRP >170 mg/L predicts severe diverticulitis with 87.5% sensitivity), lactate level (elevated in sepsis), and blood cultures 1, 3
• Start broad-spectrum IV antibiotics immediately without waiting for imaging, using carbapenem therapy (Meropenem 1 g q6h by extended infusion, Doripenem 500 mg q8h by extended infusion, or Imipenem/cilastatin 500 mg q6h by extended infusion) given the presence of hemodynamic instability 1, 3

Critical Diagnostic Imaging

• Obtain emergent CT abdomen and pelvis with IV contrast as soon as the patient is hemodynamically stable enough for transport, as this has 98-99% sensitivity and 99-100% specificity for diagnosing diverticulitis and identifying complications 1, 2
• Look specifically for extraluminal air indicating perforation (present in 10% of cases), abscess formation (16% of cases), free fluid suggesting peritonitis, and bowel wall thickening with pericolonic fat stranding 1, 4, 3
• If IV contrast is contraindicated due to severe renal disease or allergy, proceed with CT without contrast or ultrasound, though these are less accurate for detecting abscesses and complications 1

Clinical Presentation Considerations in Elderly Patients

• Recognize that elderly patients present atypically: only 50% of patients older than 65 years with acute left colonic diverticulitis have pain in the lower quadrants, only 17% have fever, and 43% do not have leukocytosis 1
• The hypotension in this case is particularly concerning as in-hospital mortality for acute left colonic diverticulitis increases significantly with age: 1.6% in patients younger than 65 years, 9.7% in patients 65-79 years, and 17.8% in patients above 80 years 1
• Comorbidities rather than age itself are the primary risk factor for mortality, so assess for diabetes, immunosuppression, chronic kidney disease, cirrhosis, and heart failure 1, 2

Treatment Algorithm Based on CT Findings

If Perforation with Diffuse Peritonitis or Feculent Peritonitis:

• Immediate emergency surgical consultation for laparotomy with colonic resection 3, 2
• Hartmann's procedure (sigmoid resection with end colostomy) is preferred in critically ill patients or those with multiple major comorbidities and hemodynamic instability 3, 5
• Primary resection with anastomosis may be considered only if the patient stabilizes rapidly and has no significant comorbidities, though this is unlikely given the presenting hypotension 4, 5

If Large Abscess (≥4 cm) Without Free Perforation:

• Percutaneous CT-guided drainage PLUS IV antibiotics for 4 days if the patient stabilizes with resuscitation 1, 3
• Continue antibiotics up to 7 days in elderly or immunocompromised patients, guided by clinical response and inflammatory markers 3
• If percutaneous drainage is not feasible or the patient remains critically ill, proceed to surgical intervention 3

If Small Abscess (<4 cm):

• IV antibiotics alone for 7 days without drainage, using carbapenem therapy given the initial hemodynamic instability 1, 3

If Uncomplicated Diverticulitis (Unlikely Given Hypotension):

• IV antibiotics for maximum 7 days given the patient's elderly age and initial hemodynamic compromise, using Ertapenem 1 g q24h or Eravacycline 1 mg/kg q12h 1, 3

Critical Pitfalls to Avoid

• Do not rely on clinical examination alone to determine severity, as misdiagnosis rates are 34-68% and elderly patients present with atypical symptoms 1
• Do not delay antibiotics waiting for imaging in a hypotensive patient, as mortality increases significantly with delayed treatment in septic shock 3, 2
• Do not assume low CRP excludes complicated diverticulitis: 39% of patients with complicated episodes have CRP below 175 mg/L 1
• Do not miss occult malignancy: 5-7% of patients with presumed diverticulitis have unsuspected colorectal cancer, so look for pericolonic lymphadenopathy >1 cm on CT 3, 4

Monitoring and Disposition

• Admit to intensive care unit for close hemodynamic monitoring given the presenting hypotension 2
• Repeat imaging if clinical deterioration occurs or if fever and leukocytosis persist beyond 48-72 hours despite appropriate treatment 3
• Surgical consultation should be obtained immediately upon diagnosis given the high-risk presentation with hypotension 1, 3