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

Initial Management of Fever with Chills

Obtain blood cultures immediately from two separate peripheral sites before any antibiotic administration, then start empiric broad-spectrum antibiotics within 1 hour if the patient shows hemodynamic instability, signs of sepsis, immunocompromise, or severe systemic toxicity. 1, 2

Immediate Risk Stratification

The presence of chills with fever represents a high-risk presentation demanding urgent evaluation. Shaking chills (whole-body shaking even under a thick blanket) carry a 12-fold increased risk of bacteremia compared to no chills, with a specificity of 90% and positive likelihood ratio of 4.65. 3 Patients ≥50 years old with fever and chills have a 55% likelihood of serious bacterial infection when combined with other risk factors. 1

Critical red flags requiring immediate action include: 1, 2

• Hemodynamic instability (systolic BP <90 mmHg, MAP <65 mmHg)
• Oxygen saturation <92%
• Altered mental status or confusion
• Lactate >2 mmol/L
• Signs of organ dysfunction
• Immunocompromised state

Diagnostic Workup Before Antibiotics

Blood cultures must be obtained within 30-90 minutes of fever onset, as bacteria are rapidly cleared from the bloodstream. 1 The diagnostic yield drops significantly if cultures are obtained after antibiotic administration. 1, 4

Essential Laboratory Tests (All Before Antibiotics):

• Two sets of blood cultures from separate peripheral sites (≥7 mL per bottle, 20-30 mL total per set) 1, 2, 4
• Complete blood count with differential (assess for leukocytosis ≥14,000 cells/mm³, left shift with bands >6%) 1, 2, 5
• Comprehensive metabolic panel and lactate level 1, 2
• Urinalysis and urine culture 1, 2
• Chest x-ray to evaluate for pneumonia 2

If the patient has any indwelling vascular catheter placed >48 hours ago, obtain one blood culture set from the catheter hub and one from a separate peripheral site simultaneously. 5 Catheter-related bloodstream infections commonly manifest as chills and rigors before temperature elevation, particularly with gram-negative organisms. 5

Empiric Antibiotic Initiation Criteria

Start empiric antibiotics immediately (within 1 hour of recognition) after obtaining cultures if any of the following are present: 6, 1, 2

• Hemodynamic instability or septic shock
• Systemic inflammatory response with suspected infection
• Immunocompromised state (neutropenia, chemotherapy, transplant)
• Suspected meningitis (altered mental status, meningismus)
• Suspected cholangitis (Charcot's triad: fever, jaundice, right upper quadrant pain)
• Cirrhosis with suspected infection (mortality increases 10% per hour of antibiotic delay) 2

Antibiotic Selection Strategy:

For severe community-acquired infections with systemic toxicity: Use intravenous combination of a broad-spectrum beta-lactamase stable antibiotic (e.g., ceftriaxone) together with a macrolide (e.g., azithromycin). 2

For nosocomial or healthcare-associated infections: Empirical therapy must cover multi-drug-resistant gram-negative bacilli and methicillin-resistant Staphylococcus aureus (MRSA). 2 This typically requires combination therapy with an anti-pseudomonal beta-lactam plus vancomycin or linezolid.

For suspected neutropenic fever: Use anti-pseudomonal monotherapy (ceftazidime or carbapenem) or combination therapy based on local resistance patterns. 6

Supportive Care Measures

For hypotensive patients, initiate immediate fluid resuscitation with 250-500 mL crystalloid boluses. 1 Serial lactate measurements should guide ongoing resuscitation efforts. 1, 2

Administer antipyretics (acetaminophen or NSAIDs) for fever control and consider prophylactic acetaminophen to reduce severity of rigors. 1 However, do not delay diagnostic workup or antibiotic administration to wait for fever response.

Monitoring Protocol:

• Vital signs every 2-4 hours (every 2 hours if hemodynamically unstable) 2, 5
• Pulse oximetry continuous monitoring 1
• Strict intake and output monitoring 1
• Mental status assessment every 8 hours 2
• Serial lactate measurements if initially elevated 1

Special Populations and Travel History

For patients with recent travel to endemic areas, immediately exclude malaria, dengue fever, enteric fever (typhoid), and rickettsial diseases. 6, 1 Malaria blood smears may be negative if obtained between paroxysms, so repeat testing is essential. 5

For suspected enteric fever in travelers from Asia: Use intravenous ceftriaxone as first-line empiric therapy, as >70% of Salmonella typhi and paratyphi isolates are fluoroquinolone-resistant. 6 Continue treatment for 14 days to reduce relapse risk.

For suspected rickettsial infection (African tick bite fever, Mediterranean spotted fever): Look for eschar at tick bite site and initiate doxycycline empirically if clinical suspicion is high. 6

Critical Pitfalls to Avoid

Do not delay blood cultures until after antibiotic administration – this reduces diagnostic yield significantly and leads to culture-negative infections. 1, 4

Do not obtain blood cultures from central venous catheters alone – this increases contamination rates. Always obtain at least one set from a peripheral site. 5, 4

Do not assume "toxic appearance" or high fever predicts bacterial infection – these are unreliable indicators. Use objective criteria including degree of chills, vital sign abnormalities, and laboratory markers. 1, 3

Do not miss atypical presentations in elderly or cirrhotic patients – they may lack fever or localizing symptoms despite serious infection. 1, 2

Do not routinely obtain blood cultures for uncomplicated cellulitis, simple pyelonephritis, or community-acquired pneumonia in stable patients – the chance of false-positive cultures exceeds true positive rates in these conditions. 4

When Antibiotics Can Be Withheld

In stable, immunocompetent patients without signs of sepsis or organ dysfunction, it is reasonable to complete the diagnostic workup and observe for 1-2 hours before initiating antibiotics, provided: 6, 1

• Blood cultures have been obtained
• Close monitoring is in place
• Antibiotics can be started immediately if clinical deterioration occurs
• No high-risk features are present (age ≥50, shaking chills, immunocompromise)

However, when in doubt, err on the side of early antibiotic administration after cultures are obtained – delay in effective antimicrobial therapy is associated with increased mortality from sepsis. 6