The febrile patient: assessment and empirical management

Manage now— do this, in order

• Answer four questions before prescribing anything: is this fever or hyperthermia; is the patient septic; is the patient neutropenic or otherwise immunosuppressed; and is there a specific immediately treatable diagnosis — meningococcaemia, malaria, rickettsial infection or necrotising soft-tissue infection.
• Resuscitate first: oxygen, two points of IV access, and blood cultures from the first venepuncture — two sets from two separate sites before antibiotics, three for suspected endocarditis or prolonged unexplained fever. Check capillary glucose immediately in anyone with altered consciousness and correct it: adult 50% dextrose 50–100 mL IV; child 10% dextrose 2 mL/kg IV.Not available at your setup — Blood culture.
• Fluids: balanced crystalloid or 0.9% sodium chloride as 500 mL boluses over 15 minutes in adults, reassessed after each, aiming for 30 mL/kg in the first hour if hypoperfusion persists; 10–20 mL/kg boluses in children. Three groups need reduced, titrated volumes: heart failure or severe valve disease, oliguric chronic kidney disease, and suspected dengue in the critical phase (5–10 mL/kg/h titrated against haematocrit, pulse pressure and urine output). Persisting hypotension: noradrenaline titrated to MAP ≥ 65 mmHg.
• If the patient is septic or neutropenic, give high-dose IV antibiotics within one hour of admission, after cultures, without waiting for a source or test results — this applies to all febrile patients on systemic anti-cancer therapy. Sepsis, unknown community source: ceftriaxone 2 g IV every 24 h (+ metronidazole 500 mg IV 8-hourly if abdominal or pelvic) or piperacillin–tazobactam 4.5 g IV 6–8-hourly. Febrile neutropenia: cefepime 2 g IV 8-hourly, piperacillin–tazobactam 4.5 g IV 6-hourly or meropenem 1 g IV 8-hourly at maximal doses, adding vancomycin 15–20 mg/kg IV 8–12-hourly for suspected MRSA, an infected line, severe mucositis or instability.Doctor / Nurse
• The specific treatable diagnoses: severe malaria — artesunate 2.4 mg/kg IV at 0, 12 and 24 hours then once daily (children under 20 kg 3 mg/kg), checking glucose hourly; suspected rickettsial illness — doxycycline 100 mg orally or IV twice daily; enteric fever — ceftriaxone 2 g IV every 24 h. Bacterial meningitis 18–50: ceftriaxone 2 g IV 12-hourly plus vancomycin 15–20 mg/kg IV 8–12-hourly, with dexamethasone 0.15 mg/kg (about 10 mg) IV 6-hourly given with or before the first antibiotic dose — the antibiotic precedes the imaging and the lumbar puncture, not the reverse.Doctor / Nurse
• Paediatric antibiotics: ceftriaxone 50 mg/kg IV (max 2 g) every 12 hours for meningitis or severe sepsis, or 80 mg/kg IV once daily for other severe infection. Ceftriaxone must not be used in neonates under 1 month — it displaces bilirubin and precipitates with calcium-containing fluids; use cefotaxime 50 mg/kg IV 6–8-hourly plus ampicillin or amoxicillin 50 mg/kg IV 6-hourly with an aminoglycoside.Doctor / Nurse
• Antipyresis, paracetamol first line: adult 1 g orally or per rectum every 6 hours, maximum 4 g in 24 hours — reduced to 2 g in 24 hours in significant liver disease, malnutrition or weight under 50 kg; child 15 mg/kg per dose every 4–6 hours, maximum 4 doses in 24 hours. Second line: ibuprofen 400 mg every 8 hours with food (child 10 mg/kg every 6–8 hours). Never aspirin in children (Reye syndrome), and avoid NSAIDs in the hypotensive, dehydrated, bleeding or renally impaired patient and in suspected dengue.
• Hyperpyrexia above 41.5°C: add physical cooling — tepid sponging, fanning, ice packs to axillae and groins, cold IV fluid — stopping at about 38.5°C and slowing if the patient shivers. In hyperthermia antipyretics are useless: cool actively, withdraw the precipitant, give dantrolene 1–2.5 mg/kg IV (max 10 mg/kg/day) for malignant hyperthermia and severe neuroleptic malignant syndrome, benzodiazepines for rigidity, and cyproheptadine 12 mg orally then 2 mg every 2 hours for serotonin syndrome.Doctor / Nurse
• If the patient is stable with no source, it is usually right not to prescribe — empirical antimicrobials for unexplained fever are rarely helpful and reduce blood culture sensitivity. Do not change the antibiotic because the fever has not settled in 24 hours (enteric fever may stay febrile up to five days, the antirickettsial response takes 48–72 hours) — judge response on pulse, blood pressure, respiratory rate, mental state, lactate and urine output. Source control matters as much as the drug: drain collections, remove infected lines, relieve obstruction, and arrange urgent surgery for necrotising soft-tissue infection.