From the Guidelines
Fever is primarily caused by the introduction of an infectious pathogen into the body, triggering a normal physiologic response to help fight and overcome infections. This response is hypothesized to play a crucial role in activating the immune system and creating an environment less favorable for pathogens to multiply 1. The evaluation and management of fever, especially in pediatric patients, is evolving due to advances in research, vaccination (such as Haemophilus influenzae type b and Streptococcus pneumoniae vaccines), and diagnostic technologies 1.
Causes of Fever
- Infectious pathogens
- Noninfectious causes, including malignant hyperthermia and neuroleptic malignant syndrome, which can be devastating if left untreated 1
- Drug-induced fever, which can occur due to hypersensitivity to any drug, with symptoms not always appearing immediately after drug administration 1
- Withdrawal from certain drugs like alcohol, opiates, barbiturates, and benzodiazepines, which can lead to fever, tachycardia, diaphoresis, and hyperreflexia 1
Management of Fever
- For adults, managing fever involves taking acetaminophen (Tylenol) 325-650mg every 4-6 hours or ibuprofen (Advil, Motrin) 200-400mg every 6-8 hours as needed, not exceeding maximum daily doses (4000mg for acetaminophen, 3200mg for ibuprofen) 1.
- For children, weight-based dosing of medications as indicated on packaging is recommended.
- Staying hydrated by drinking plenty of fluids, resting, and dressing in lightweight clothing can help manage fever.
- Applying cool compresses if comfortable can also provide relief.
- Seeking medical attention is crucial if fever exceeds 103°F (39.4°C) in adults, persists more than three days, or is accompanied by severe headache, stiff neck, confusion, difficulty breathing, rash, or persistent vomiting 1.
Fever itself is not an illness but a protective mechanism. Understanding its causes, whether infectious or noninfectious, is key to appropriate management and preventing potential complications. Given the evolving nature of fever management, especially with advancements in vaccination and diagnostic technologies, it's essential to stay updated with the latest guidelines and research findings 1.
From the Research
Causes of Pyrexia (Fever)
- Fever can result from infection or inflammation 2
- The broad differential diagnosis of fever includes numerous infectious and non-infectious etiologies 3
- Fever can be due to infectious or non-infectious etiology and results from the body's natural response to a pyrogen 3
- Fever is a physiologic mechanism that has beneficial effects in fighting infection 4
Pathophysiology of Fever
- Fever occurs frequently in critically ill patients and requires knowledgeable assessment and treatment by critical care nurses 2
- The physiologic consequences of fever may affect patient morbidity 2
- Fever is not the primary illness but is a physiologic mechanism that has beneficial effects in fighting infection 4
Diagnosis and Evaluation of Fever
- Adjunctive testing including C-reactive protein, erythrocyte sedimentation rate, and procalcitonin has been evaluated in the literature, but these tests do not have the needed sensitivity and specificity to definitively rule in a bacterial cause of fever 3
- Blood cultures should be obtained in septic shock or if the results will change clinical management 3
- Oral temperatures suffer from poor sensitivity to diagnose fever, and core temperatures should be utilized if concern for fever is present 3
- Consideration of non-infectious causes of elevated temperature is needed based on the clinical situation 3