Fever

on call  ›  vitals  ›  fever

Fever

ABCs
  • check vitals and random blood glucose
  • recheck temperature (oral / axillary vs tympanic discrepancies)
  • assess deterioration signs: hypotension, tachypnea, desaturation, confusion
  • escalate if patient in shock
escalate early
  • hemodynamic instability
  • tachypnea or desaturation
  • confusion or new altered mental status
  • neutropenic patient
HPI
  • onset, duration, pattern
  • fever details new vs persistent, trend, measurement method
  • identify focal infection source
  • sick contacts or food exposure
  • chart review
    • current infection treatment
    • antibiotic use
    • admission length
    • MRSA or Pseudomonas risk
    • immunocompromised status
    • renal function-adjusted dosing
  • prior 24 hours surgery, line insertion, new medications, ICU transfer
system review
  • CNS headache, confusion, seizures, N/V, photophobia, neck stiffness
  • ENT purulent ear discharge, sinus tenderness, mastoid pain
  • cardiac pleuritic chest pain (positional relief), new murmur
  • respiratory cough, dyspnea, hemoptysis, chest pain, aspiration risk, ventilator changes
  • GI abdominal pain, bowel changes, N/V
  • skin / soft tissue cellulitis, ulcers, sores, cannula or surgical sites
  • rheum / MSK joint swelling, joint pain, rash, myalgia, bone pain
  • GU dysuria, hematuria, frequency, flank pain
  • gyne vaginal discharge, pelvic pain
  • devices pacemaker, PEG, Foley, central line, tracheostomy sites
examination
  • system-tailored approach
  • don’t omit joint assessment, cannula/wound inspection, chest and cardiac auscultation, surgical site palpation
workup
review available investigations
  • leukocytosis or neutropenia
  • CRP or PCT trends
  • previous culture results
  • recent viral swab results
  • CXR findings
if stable
  • CBC with differential, CRP ± PCT
  • trace pending cultures, viral swabs
  • CXR
  • monitor trends
if new, unwell, or worsening (full septic screen)
  • CBC, CRP, PCT, LFT, RFT, lactic acid
  • urinalysis + culture
  • stool culture ± C. difficile testing
  • blood cultures × 2 (different sites)
  • sputum culture ± endotracheal aspirate
  • wound or ulcer swab
  • line tip culture if removed
  • soft tissue ultrasound (if needed)
  • CXR
  • consider surgical referral (diabetic foot, ulcers)
management
febrile neutropenia, do not wait
  • any fever in a neutropenic patient = emergency
  • start an antipseudomonal β-lactam within 60 min piperacillin-tazobactam 4.5 g IV q6h (or cefepime 2 g IV q8h)
  • add vancomycin 15 mg/kg IV q12h only for line infection, skin/soft-tissue, mucositis, or instability
  • send cultures first only if this does not delay the first dose; discuss with Microbiology / ID
clinically stable and investigated
  • reassess pending results
  • paracetamol 1 g IV q6h (max 4 g/day, less in liver disease)
new onset, unwell, or deteriorating
  • send cultures first (if safe)
  • start empiric antibiotics early
  • adjust dosing for renal function
antibiotic selection
  • site of infection
  • severity level
  • immune status
  • prior cultures and resistance patterns
  • local resistance patterns
  • MRSA or Pseudomonas risk
  • consider Microbiology / ID consult if complex
if called about positive cultures
  • verify appropriate antibiotic coverage
  • review organism sensitivities
  • adjust antibiotic choice
  • repeat CBC and CRP for response
  • consider Microbiology / ID consult
  • review dose and duration
empiric antibiotics by source
  • confirm against current local policy
  • community-acquired pneumonia, ward moxifloxacin 400 mg IV/PO q24h or levofloxacin 750 mg IV/PO q24h; or ceftriaxone 1–2 g IV q24h + azithromycin 500 mg q24h (ICU: ceftriaxone + macrolide)
  • hospital-acquired pneumonia piperacillin-tazobactam 4.5 g IV q6h or cefepime 2 g IV q8h; add vancomycin 15 mg/kg q12h (or linezolid 600 mg q12h) if MRSA risk
  • febrile UTI / complicated urinary levofloxacin 750 mg IV/PO q24h or piperacillin-tazobactam 4.5 g IV q6h
  • biliary (cholangitis / cholecystitis) piperacillin-tazobactam 3.375 g IV q6h (life-threatening imipenem 0.5 g IV q6h)
  • secondary peritonitis (perforation / abscess) meropenem 1 g IV q8h, or ceftolozane-tazobactam 1.5 g IV q8h + metronidazole 500 mg q8h
  • spontaneous bacterial peritonitis ceftriaxone 2 g IV q24h
  • cellulitis, extremities penicillin G 1–2 MU IV q6h (or cefazolin 1 g IV q8h); facial or MRSA risk vancomycin 15–20 mg/kg q12h
  • necrotizing fasciitis vancomycin 15–20 mg/kg IV q8–12h + piperacillin-tazobactam 3.375 g IV q6h + clindamycin 900 mg q8h; urgent surgery
  • meningitis ceftriaxone 2 g IV q12h + vancomycin 15–20 mg/kg q12h ± dexamethasone 10 mg IV (≈0.15 mg/kg) q6h ×4 days; add ampicillin 2 g IV q4h if >50 y or immunocompromised
  • central line-associated bloodstream vancomycin 15 mg/kg IV q12h + cefepime 2 g IV q8h (femoral line add anidulafungin); consider line removal
  • source unclear identify and treat per the relevant section; if truly unknown, broad-spectrum per Micro advice (e.g. piperacillin-tazobactam 4.5 g IV q6h ± vancomycin if MRSA risk)
  • always: cultures before antibiotics where safe · review all IV antibiotics at 48 h · IV→PO switch early · renal-adjust with pharmacy · discuss with Micro if unsure
go deeper MOC+ Vol 1 · Acute Infections covers this in the full reference. or the complete set.
studying for the IM exam? the IM Rapid Review covers fever workup and sepsis in the same format. see the sample chapter.

Last reviewed · June 2026

MOC