What is the protocol for managing fever in an adult hospital patient?

Protocol for Fever Management in Hospitalized Adults

For adult hospital patients with new fever, prioritize accurate temperature measurement using central methods (bladder catheter, esophageal thermistor) or oral/rectal routes, perform targeted diagnostic workup based on clinical assessment rather than reflexive testing, and use antipyretics primarily for symptomatic relief rather than temperature reduction alone. 1, 2

Temperature Measurement

Use the most reliable method available for accurate fever detection:

• Central monitoring is preferred when devices are already in place: pulmonary artery catheter thermistors, bladder catheters, or esophageal balloon thermistors 1, 2
• Oral or rectal temperatures are recommended when central monitoring is unavailable 1, 2
• Avoid unreliable methods including axillary, tympanic membrane, temporal artery thermometers, or chemical dot thermometers for clinical decision-making 1, 2
• Fever is defined as a single temperature measurement ≥38.3°C (101°F) 2

Initial Clinical Assessment

Conduct a focused history and physical examination to identify potential infectious and non-infectious sources:

• Evaluate for infectious causes: pneumonia (most common in ICU), urinary tract infection, catheter-related bloodstream infection, surgical site infection, sinusitis 1, 2
• Consider non-infectious causes: drug fever, venous thrombosis, pulmonary embolism, acalculous cholecystitis, pancreatitis, acute myocardial infarction, stroke, malignancy, transfusion reactions 1
• Not all fevers require investigation—those with obvious non-infectious etiology (e.g., immediate postoperative period) may not need extensive workup 1

Diagnostic Workup

Tailor investigations based on clinical suspicion rather than ordering reflexive "fever workup":

Imaging Studies

• Chest radiograph is recommended for all ICU patients with new fever, as pneumonia is the most common infection causing fever in critically ill patients 3, 2
• CT imaging should be performed for post-surgical patients (thoracic, abdominal, or pelvic surgery) with persistent fever when initial workup is non-diagnostic 1, 2
• Bedside diagnostic ultrasound of the abdomen is recommended for patients with recent abdominal surgery or abdominal symptoms 1, 2

Microbiological Studies

• Blood cultures should be obtained before initiating antimicrobial therapy, particularly if the patient is seriously ill or deteriorating 2
• Targeted cultures based on suspected source (sputum, urine, wound, catheter tip) rather than reflexive pan-culturing 1
• Rapid diagnostic testing strategies are recommended when available 1

Laboratory Tests

• Biomarkers (procalcitonin, C-reactive protein) can assist in guiding discontinuation of antimicrobial therapy 1
• Consider complete blood count, metabolic panel, liver function tests, lactate dehydrogenase based on clinical context 1

Antipyretic Therapy

Antipyretics should be used primarily for symptomatic relief and patient comfort, not routinely to reduce temperature:

First-Line Treatment

• Paracetamol (acetaminophen) 1000 mg orally every 4-6 hours (maximum 4 g/day) is the first-line antipyretic for patients capable of oral intake 3, 4
• Paracetamol has superior cardiovascular and gastrointestinal safety compared to NSAIDs 3
• Paracetamol/ibuprofen combination (500 mg/150 mg) may be more effective than paracetamol alone for bacterial fever at 1 hour, though both are equally effective at 2 hours 4

Route Selection

• Oral route is preferred for all patients capable of oral intake 3
• Intravenous paracetamol is preferable when IV access exists and patients cannot take oral medications due to persistent vomiting, altered mental status, or NPO status 3
• Avoid intramuscular route due to injection site pain, tissue trauma, and risk of hematoma (especially in anticoagulated patients) 3

Dosing Considerations

• Reduce dosage in patients with hepatic insufficiency or history of alcohol abuse 3
• Contraindicated in acute liver failure 3

Evidence on Mortality

• Antipyretic therapy does not improve mortality outcomes: A meta-analysis of 13 RCTs (n=1,963) showed no improvement in 28-day mortality (RR 1.03; 95% CI 0.79-1.35), hospital mortality, or shock reversal 3, 5
• Therefore, treat for comfort, not the thermometer reading 3, 2

Non-Pharmacologic Measures

Physical cooling methods are generally not recommended:

• Avoid routine physical cooling (tepid sponging, fanning) as these cause discomfort without improving outcomes 3
• Cooling devices should only be considered for refractory fevers unresponsive to antipyretics 3
• Environmental measures are acceptable: reduce excessive stimuli, lower ambient temperature during hot months, uncover patient as tolerated 3
• Maintain head of bed elevation 15-30° to prevent aspiration 3

Special Populations and Contexts

Post-Surgical Patients

• Fever immediately postoperatively typically does not require investigation 1
• Persistent fever beyond several days without identified cause warrants CT imaging of the surgical area in collaboration with surgical service 3, 2

Critically Ill/ICU Patients

• Fever occurs in 26-88% of adult ICU patients depending on definition and cohort 1
• Early antimicrobial therapy may improve outcomes when infection is suspected—do not delay effective treatment 2
• Diagnostic studies should focus on potential sources identified by history and examination rather than reflexive testing 1

Neutropenic Patients

• Hospitalization and empiric antibacterial therapy with vancomycin plus antipseudomonal antibiotics is recommended for neutropenic fever 2
• Consider discontinuation at 72 hours in low-risk patients with negative cultures who have been afebrile ≥24 hours 2

Common Pitfalls to Avoid

• Do not treat the thermometer reading rather than the patient's symptoms and comfort 2
• Do not use unreliable temperature methods (tympanic, temporal) for critical decisions 2
• Do not delay antimicrobial therapy when infection is suspected—this increases mortality 2
• Do not order reflexive pan-cultures without clinical suspicion of specific sources 1
• Do not use antipyretics routinely just to reduce temperature in the absence of patient discomfort 3, 2