What is the initial management for a patient presenting with fever and altered sensorium?

Initial Management of Fever with Altered Sensorium

Immediately administer empiric broad-spectrum antibiotics within one hour—ceftriaxone 2g IV plus vancomycin 15-20 mg/kg IV—without waiting for diagnostic confirmation, as delay in treatment significantly increases mortality from bacterial meningitis and meningococcal sepsis. 1

Immediate Actions (Within First Hour)

Ensure Rapid Transport and Stabilization

• Arrange emergency transport to arrive within one hour of initial assessment, as delays directly increase mortality 1
• Obtain IV access and initiate fluid resuscitation if hypotensive 1
• Monitor vital signs continuously, including temperature, blood pressure, heart rate, and oxygen saturation 1

Initiate Empiric Antimicrobial Therapy Immediately

Do not delay antibiotics while awaiting lumbar puncture or imaging studies 1

• Ceftriaxone 2g IV to cover Neisseria meningitidis and Streptococcus pneumoniae (including resistant strains) 1
• Vancomycin 15-20 mg/kg IV for additional pneumococcal coverage 1
• Add ampicillin 2g IV every 4 hours if patient is >50 years old, immunocompromised, or has risk factors for Listeria monocytogenes 1
• Add acyclovir 10 mg/kg IV every 8 hours if herpes simplex encephalitis is suspected (altered mental status ≥24 hours with fever, seizures, or focal neurologic findings) 1, 2

Consider Rickettsial Disease

• Initiate doxycycline 100mg IV/PO twice daily immediately if there is any history of tick exposure, outdoor activities in wooded/grassy areas, or geographic risk (Rocky Mountain region, southeastern US), as early treatment within first 3 days is critical to prevent mortality 1, 3
• Do not wait for laboratory confirmation or characteristic rash, which often appears late (days 2-4) or not at all 1, 3
• Most patients do not recall tick bites, so absence of reported exposure does not exclude rickettsial disease 3

Critical Clinical Assessment

Document Specific Features

• Mental status: Use Glasgow Coma Scale; document specific deficits (confusion, somnolence, unresponsiveness to commands) 1, 4
• Meningeal signs: Check for neck stiffness, Kernig's sign, Brudzinski's sign (note: elderly patients often lack these findings) 1
• Rash characteristics: Petechial, purpuric, maculopapular; distribution and progression 1
• Seizure activity: Any witnessed seizures or postictal state 1
• Signs of shock: Hypotension, prolonged capillary refill time (>2 seconds), cold extremities 1

Obtain Focused History

• Travel history: Any travel within past year to tropical/subtropical regions; most tropical infections present within 21 days of exposure 5, 3
• Tick exposure: Outdoor activities, camping, hiking in endemic areas 1, 3
• Animal contacts: Unpasteurized dairy products (brucellosis), cats (Bartonella), livestock 5, 6
• Immunization status: Particularly meningococcal vaccine 1
• Immunocompromised state: HIV, chemotherapy, transplant, chronic steroids 1

Essential Diagnostic Studies (Do Not Delay Treatment)

Immediate Laboratory Testing

• Blood cultures: Two sets (one peripheral, one from central line if present) before antibiotics 1, 3
• CBC with differential: Look for leukopenia (viral infections, typhoid, rickettsial disease), thrombocytopenia (malaria, dengue, rickettsial disease, meningococcemia), or lymphopenia 5, 1, 3
• Comprehensive metabolic panel: Assess for hyponatremia (SIADH from meningitis), renal dysfunction, elevated transaminases (rickettsial disease, viral hepatitis) 1, 3
• Coagulation studies: PT/INR to assess for coagulopathy in meningococcemia or dengue 1, 7
• Lactate: Elevated lactate >4 mmol/L indicates poor prognosis in meningococcal disease 1
• Malaria testing: Three thick/thin blood films or rapid diagnostic tests over 72 hours if any tropical travel within past year 5, 3

Lumbar Puncture

• Perform urgently but do not delay antibiotics if LP cannot be done immediately 1
• Contraindications to immediate LP: Signs of increased intracranial pressure (papilledema, focal neurologic deficits, altered consciousness with GCS <12), coagulopathy, thrombocytopenia <50,000, hemodynamic instability 5, 1
• If contraindications present: Obtain CT head first, but give antibiotics before imaging 1
• CSF studies: Cell count with differential, glucose, protein, Gram stain, bacterial culture, HSV PCR, enterovirus PCR 1

Neuroimaging

• CT head without contrast: Obtain before LP if focal neurologic signs, papilledema, immunocompromised state, or GCS <12 1
• MRI brain with contrast: More sensitive for encephalitis, abscess, or early cerebritis; obtain if diagnosis remains unclear after initial workup 1

Risk Stratification for Severe Disease

High-Risk Features for Fatal Outcome (Meningococcal Disease)

• Rapidly progressing petechial/purpuric rash 1
• Coma or profound altered consciousness 1
• Hypotension and shock 1
• Lactate >4 mmol/L 1
• Low or normal white blood cell count (paradoxical leukopenia) 1
• Thrombocytopenia and coagulopathy 1
• Absence of meningitis (sepsis alone carries worse prognosis) 1

Special Population Considerations

Elderly Patients (>50 Years)

• More likely to have altered consciousness and less likely to have fever or neck stiffness 1
• Always add ampicillin for Listeria coverage 1
• Higher risk for pneumococcal disease 1

Immunocompromised Patients

• May not mount typical inflammatory response; CSF findings can be minimal 1
• Broader differential includes fungal infections (cryptococcus, histoplasmosis), toxoplasmosis, tuberculosis 1
• Lower threshold for hospitalization and empiric therapy 3

Pregnant Patients

• Dengue encephalopathy can present with fever and altered sensorium without circulatory compromise 4
• Cautious fluid management required; monitor hematological parameters closely 4
• Physiological changes in pregnancy can mask typical infection signs 4

Travelers from Endemic Areas

• Malaria: Must be excluded with three tests over 72 hours; can present with altered consciousness without localizing signs 5
• Enteric fever (typhoid): Consider empiric ceftriaxone if clinically unstable; ciprofloxacin if from sub-Saharan Africa and sensitive 5
• Dengue: Can cause encephalopathy; manage supportively, avoid aspirin 5, 4
• Leptospirosis: Empiric doxycycline or penicillin if appropriate exposure history 5

Critical Pitfalls to Avoid

• Never delay antibiotics for lumbar puncture, imaging, or laboratory confirmation 1
• Never assume absence of tick bite excludes rickettsial disease; most patients don't recall exposure 3
• Never rely on early serologic testing for rickettsial diseases; treatment decisions must be based on clinical findings 3
• Never misinterpret altered sensorium as "fever delirium" without excluding life-threatening infections 7
• Never withhold doxycycline in children with suspected rickettsial disease; it is the treatment of choice regardless of age 1
• Never forget ampicillin in elderly or immunocompromised patients 1

Monitoring and Disposition

• ICU admission for patients with altered consciousness, hemodynamic instability, or rapidly progressive disease 5, 1
• Frequent reassessment as patients can deteriorate rapidly even if initially appearing stable 1
• Monitor hourly: Mental status, vital signs, urine output, capillary refill 1
• Serial laboratory monitoring: CBC, coagulation studies, lactate, renal function 1, 7