What is the protocol for referring a patient with septic shock from hospital-acquired pneumonia (HAP) to an infectious disease consultant?

Referral Protocol for Septic Shock from Hospital-Acquired Pneumonia

Initiate immediate empiric antibiotics BEFORE consulting infectious disease—do not delay treatment for consultation, as septic shock from HAP requires urgent antimicrobial therapy within the first hour to reduce mortality. 1

Immediate Actions (Within 1 Hour)

1. Start Empiric Antibiotics Immediately

• Septic shock is an absolute indication for immediate broad-spectrum antibiotics covering multidrug-resistant (MDR) pathogens, regardless of time to ID consultation 1
• Use combination therapy with two antipseudomonal agents plus MRSA coverage 1:
  • Antipseudomonal β-lactam (piperacillin-tazobactam 4.5g IV q6h, cefepime 2g IV q8h, or meropenem 1g IV q8h) 1
  • PLUS aminoglycoside (amikacin 15-20 mg/kg IV daily) OR fluoroquinolone (levofloxacin 750mg IV daily) 1
  • PLUS anti-MRSA agent (vancomycin 15mg/kg IV q8-12h targeting 15-20 mg/mL trough, or linezolid 600mg IV q12h) 1

2. Collect Microbiological Samples BEFORE Antibiotics (If Possible)

• Blood cultures (two sets from separate sites) 1
• Respiratory samples: sputum culture, endotracheal aspirate if intubated, or consider bronchoscopy with bronchoalveolar lavage 1, 2
• Do not delay antibiotics >1 hour to obtain samples 1

When to Consult Infectious Disease

Immediate Consultation (Stat/Urgent Page)

Contact ID immediately for any of the following 1, 3:

• Septic shock present (systolic BP <90 mmHg requiring vasopressors, lactate >2 mmol/L) 1, 3
• High mortality risk (>25% predicted mortality, multiorgan failure) 1
• Prior antibiotic use within 90 days (increases MDR risk 13.5-fold) 3
• Hospitalization ≥5 days (increases MDR risk 6-fold) 3
• Known MDR pathogen colonization (MRSA, Pseudomonas, Acinetobacter, ESBL organisms) 1, 3
• Immunosuppression (chemotherapy, transplant, chronic steroids) 1

Information to Provide in Consultation Request

Patient Demographics & Timing:

• Age, admission date, HAP onset date (must be ≥48 hours post-admission) 2
• ICU vs. ward location, mechanical ventilation status and duration 2, 3

Clinical Severity Markers:

• Hemodynamic status: blood pressure, vasopressor requirements, lactate level 1
• Respiratory status: oxygen requirement, PaO2/FiO2 ratio, mechanical ventilation 1
• Organ dysfunction: renal function (creatinine, urine output), liver enzymes, platelet count 1

MDR Risk Factors Present:

• Antibiotic exposure in past 90 days (specify agents and duration) 1, 3
• Prior hospitalization or nursing home residence in past 90 days 1, 3
• Chronic dialysis, home infusion therapy, or wound care 1, 3
• Known MDR colonization history from prior cultures 1, 3
• Local ICU antibiogram data if available (MRSA prevalence, Pseudomonas resistance patterns) 1

Microbiological Data:

• Cultures obtained (blood, respiratory) with timing relative to antibiotics 1
• Gram stain results if available (numerous gram-negative bacilli suggest Pseudomonas/Acinetobacter) 1
• Prior culture results from current admission 1

Current Antibiotic Regimen:

• Specific agents, doses, and start times 1
• Any drug allergies or intolerances 1

What ID Consultation Will Address

The infectious disease consultant will optimize management by 1:

• Confirming appropriate empiric coverage based on local resistance patterns and patient-specific MDR risk factors 1
• Adjusting therapy if inadequate coverage identified (e.g., adding polymyxins for carbapenem-resistant organisms) 1
• De-escalating to targeted therapy once culture results available (typically 48-72 hours) 1
• Optimizing pharmacokinetics/pharmacodynamics (extended infusions, therapeutic drug monitoring for vancomycin/aminoglycosides) 1
• Determining treatment duration (typically 7-8 days for good clinical response) 2
• Considering adjunctive inhaled antibiotics if not responding to IV therapy alone 1

Common Pitfalls to Avoid

• Never delay antibiotics waiting for ID consultation—septic shock requires treatment within 1 hour 1
• Do not use monotherapy in septic shock from HAP—combination therapy reduces mortality when MDR pathogens present 1
• Avoid aminoglycoside monotherapy for Pseudomonas—associated with treatment failure 1
• Do not assume early-onset HAP (<5 days) is low-risk if patient has prior antibiotics or hospitalization within 90 days 3
• Ensure MRSA coverage if local ICU prevalence >20% or prevalence unknown 1