What is the workup for a complicated first episode of sepsis?

Workup for a Complicated First Episode of Sepsis

The workup for a complicated first episode of sepsis must include obtaining appropriate cultures before starting antimicrobial therapy, rapid administration of broad-spectrum antibiotics within one hour of recognition, and prompt imaging to identify the source of infection. 1, 2

Initial Assessment and Diagnosis

• Vital signs assessment: Monitor heart rate, blood pressure, arterial oxygen saturation, respiratory rate, temperature, and urine output 1

• Laboratory studies:

  • Complete blood count with differential
  • Comprehensive metabolic panel
  • Coagulation studies
  • Lactate level (marker of tissue hypoperfusion)
  • Blood cultures (at least 2 sets, aerobic and anaerobic)
  • Urinalysis and urine culture
  • Other cultures based on suspected source

• Microbiological sampling:

  • Obtain blood cultures before starting antimicrobials if no substantial delay (>45 minutes) 1
  • Sample fluid or tissue from suspected infection sites 1
  • Examine samples by Gram stain, culture, and antibiotic susceptibility testing 1

Imaging Studies

• CT scan with IV contrast: First-line imaging for adults not undergoing immediate surgery to determine presence and source of intra-abdominal infection 1
• Chest imaging: Consider chest CT with IV contrast for suspected pulmonary source 1
• FDG-PET/CT: Consider for sepsis of unknown origin after initial workup including unrevealing chest radiography 1
  • Has shown 66-78% positive findings in identifying infection sources
  • Can lead to treatment modifications in 25-33% of patients

Hemodynamic Assessment

• Initial fluid resuscitation: Administer at least 30 mL/kg of IV crystalloids within first 3 hours 1, 2
• Hemodynamic monitoring:
  • Use dynamic variables rather than static variables to predict fluid responsiveness 1
  • Consider echocardiography for detailed assessment of hemodynamic issues 1
  • Target MAP ≥65 mmHg in patients requiring vasopressors 1
  • Monitor for normalization of lactate in patients with elevated levels 1

Source Control

• Source identification: Perform detailed patient history and thorough clinical examination 1
• Source control procedures: Implement appropriate interventions to drain infected foci, control peritoneal contamination, and restore anatomic function 1
  • For diffuse peritonitis: Emergency surgical procedure as soon as possible 1
  • For well-localized fluid collections: Percutaneous drainage when feasible 1
  • For hemodynamically stable patients without organ failure: Intervention may be delayed up to 24 hours if appropriate antimicrobial therapy is given 1

Antimicrobial Therapy

• Timing: Administer within first hour of recognition of septic shock and severe sepsis 1
• Selection: Choose empiric therapy active against all likely pathogens with adequate tissue penetration 1
• Reassessment: Daily review of antimicrobial regimen for potential de-escalation 1
• Biomarkers: Consider procalcitonin levels to guide discontinuation of empiric antibiotics when no subsequent evidence of infection 1

Special Considerations

• Clinical factors predicting failure of source control 1:

  • Delay in initial intervention (>24h)
  • High severity of illness (APACHE II score ≥15)
  • Advanced age
  • Comorbidities and organ dysfunction
  • Low albumin levels
  • Poor nutritional status
  • Diffuse peritonitis
  • Inadequate debridement or drainage
  • Presence of malignancy

• Regional considerations: Adjust empiric antimicrobial therapy to local infectious disease patterns, pathogen spectrum, and antimicrobial resistance 1

Ongoing Monitoring

• Reassessment parameters:

  • Vital signs
  • Urine output (target ≥0.5 mL/kg/hr)
  • Mental status
  • Capillary refill
  • Skin temperature and appearance
  • Peripheral pulses 2

• Performance improvement: Implement hospital-wide sepsis screening and management protocols 1, 2

By following this structured approach to the workup of a complicated first episode of sepsis, clinicians can ensure timely identification of the infection source, appropriate antimicrobial therapy, and necessary interventions to improve patient outcomes and reduce mortality.