Approach to Fever in Hospitalized (or Recently Hospitalized) Patients

Important to think about both infectious and non-infectious etiologies; i.e, not every fever means infection!  (although it usually does). 

A. INFECTIOUS ETIOLOGIES

• Catheter-related infections
• Surgical Site infections
• Hospital-acquired pneumonia – very common, especially in the ICU with ventilators
• UTI’s and foley catheter-related infections – this is a little trickier to definitively diagnose and to distinguish colonization vs true infection.
• C.diff-associated diarrhea - esp if on recent abxs, although this is not a prerequisite
• Thrombophlebitis – infected clot, often at the site of catheter or recently removed catheter
• Infected sacral decub ulcers - remember to always turn the patient over to check for this!  Late stage decub ulcers are sometimes complicated by osteomyelitis as well. 

Other less common causes: cholangitis, diverticulitis, osteomyelitis, endocarditis, intraabdominal abscesess, meningitis, etc.

B. NONINFECTIOUS ETIOLOGIES

• Thromboembolic disease – but generally, not recommended to screen until other common causes have been ruled out, or if signs/symptoms to suggest this
• Drug fever – notoriously difficult to diagnose, as it can occur several days after starting the offending drug and take days to subside after stopping!  Generally a diagnosis of exclusion.
• Transfusion reaction – typically want to rule out infection though
• Atelectasis? - this is a controversial subject, but probably it doesn't cause fever without co-existing pulmonary infection.
• Adrenal insufficiency – can present very similarly to sepsis, with hypotension, fevers, etc.
• Thyrotoxicosis
• Benign postop fever – usually no need to worry if in the immediate postop period.  Remember that atelectasis does not cause fever, despite the myth propagated by Surgical Recall!
• Intracranial hemorrhage
• Malignancy (Tumor fever) – usually a diagnosis of exclusion
• Vasculitis
• Intraabdominal processes – i.e. pancreatitis, acalculous cholecystitis (fairly common and potentially devastating in critically ill patients)

With this differential in mind, you can approach your physical exam accordingly… i.e. in addition to the standard heart lungs abd ext exam, also look closely at: current or past catheter sites, surgical sites, backside for decubitus ulcers, examine sinuses for signs of tenderness to suggest sinusitis, look for unilateral leg edema, etc. 

(Chanu Rhee MD, 4/8/11)