What is the best course of treatment for a 73-year-old female with abdominal pain, vomiting, fever, and hypotension, with lab results indicating leukopenia, anemia, and moderate bacteruria?

Management of Sepsis with Suspected Intra-Abdominal Source in an Elderly Patient

This 73-year-old woman presenting with hypotension (BP 80), fever, vomiting, abdominal pain, and leukopenia requires immediate resuscitation, broad-spectrum intravenous antibiotics targeting intra-abdominal infection, and urgent CT imaging to identify a source requiring surgical intervention.

Immediate Resuscitation and Stabilization

• Aggressive fluid resuscitation is the first priority given the documented hypotension (BP 80 mmHg), which represents septic shock requiring immediate intervention 1
• Supplemental oxygen should be continued to maintain adequate tissue perfusion 1
• Continuous monitoring with cardiac telemetry and pulse oximetry is essential for patients with hypotension and sepsis 1
• Serial lactate measurements and blood gas analysis should guide resuscitation adequacy 1

Diagnostic Workup

CT abdomen and pelvis with IV contrast is the most critical next step to identify the source of intra-abdominal infection, as this patient's presentation (abdominal pain, vomiting, fever, hypotension) strongly suggests complicated intra-abdominal pathology requiring source control 1. The guideline explicitly states that CT is "usually the most accurate method by which to diagnose an ongoing or recurrent intra-abdominal infection" 1.

Key diagnostic considerations:

• Blood cultures (at least 2 sets) before antibiotics 1
• Repeat CBC to monitor leukopenia (currently 3.20, down from 4.40) 2
• Comprehensive metabolic panel including lactate 1
• The moderate bacteria on fecalysis suggests possible gastrointestinal source 1

Antibiotic Management

Discontinue the current inadequate regimen immediately. The ER-prescribed cefuroxime 500mg q12h is insufficient for septic shock with suspected intra-abdominal infection 1.

Initiate broad-spectrum IV antibiotics covering gram-negative aerobes, anaerobes, and resistant organisms:

• The worsening leukopenia (4.40→3.20) and clinical deterioration on cefuroxime indicates treatment failure 3
• For healthcare-associated complicated intra-abdominal infection with septic shock, empiric coverage must include anti-pseudomonal agents and anaerobic coverage 1
• A reasonable regimen would be piperacillin-tazobactam 4.5g IV q6h OR meropenem 1g IV q8h PLUS metronidazole if using a non-beta-lactam/beta-lactamase inhibitor combination 1

Duration of therapy:

• If source control is achieved surgically, antibiotics should continue for 4-7 days post-procedure 1, 4
• Recent high-quality evidence supports 7 days of antibiotic therapy for bloodstream infections in hospitalized patients, which was noninferior to 14 days (mortality difference -1.6%, 95% CI -4.0 to 0.8) 5
• Therapy should be adjusted based on culture results and clinical response 1

Source Control Evaluation

Surgical consultation is mandatory as this patient likely requires procedural intervention 1. The guidelines emphasize that "patients with persistent or recurrent signs of peritoneal irritation, failure of bowel function to return to normal, or continued fever or leukocytosis are at high risk of an intra-abdominal or other infection that may require additional intervention to achieve source control" 1.

Potential sources requiring intervention:

• Perforated viscus (given acute presentation with vomiting and hypotension)
• Complicated diverticulitis with abscess or perforation
• Cholecystitis or cholangitis
• Bowel obstruction with ischemia

Critical Pitfalls to Avoid

The leukopenia (WBC 3.20) is concerning and requires specific attention:

• This may represent overwhelming sepsis with bone marrow suppression 6
• Cephalosporins can cause leukopenia, particularly at high doses for >1 week, though this patient received only standard doses for a short duration 3
• The declining WBC (4.40→3.20) suggests disease progression rather than drug effect 3

Do not attribute the bacteriuria (UA with 3-5 WBC, 2-4 RBC) as the primary source without imaging, as the clinical presentation with abdominal pain and vomiting points to intra-abdominal pathology 1. The asymptomatic bacteriuria guidelines specifically state not to treat bacteriuria in elderly patients without localizing genitourinary symptoms 1, but this patient has systemic sepsis requiring source identification.

The "nanigas" (rigidity) and extended arms with hard jaw described the day before presentation suggests possible peritoneal signs or severe systemic toxicity, making intra-abdominal catastrophe highly likely 1.

Monitoring Parameters

• Vital signs every 1-2 hours until stable 1
• Daily CBC to monitor leukopenia and anemia (Hgb dropped from 124→111) 2
• Daily comprehensive metabolic panel for renal function and electrolytes 1
• Lactate clearance as marker of resuscitation adequacy 1
• Clinical reassessment for signs of peritonitis or clinical deterioration 1

If no source is identified on CT and patient fails to improve within 48-72 hours despite appropriate antibiotics, consider alternative diagnoses including extra-abdominal infections, though the clinical picture strongly favors intra-abdominal pathology 1.