Management of Fever and Rigors

Pharmacologic Interventions

The American Society of Clinical Oncology recommends administering parenteral opioids, such as meperidine or hydromorphone, for immediate symptom control of rigors, combined with prophylactic acetaminophen to reduce severity and prevent escalation 1, 2
Administer acetaminophen prophylactically to reduce the severity and escalation of rigors and associated fever, with a recommended dose of 1000 mg orally every 4-6 hours, maximum 4 g/day in adults 1, 2, 4
NSAIDs can be added to acetaminophen for enhanced prophylaxis against recurrent rigors 1, 2

Obtain blood cultures immediately before any antibiotic administration, ideally within 30-90 minutes of symptom onset, as recommended by the Infectious Diseases Society of America 4
Complete blood count with differential, comprehensive metabolic panel, lactate level, and chest radiograph as pneumonia is the most common infectious cause in critically ill patients 4, 5, 6
Urinalysis and urine culture should be performed to identify potential urinary tract infections 4

The Infectious Diseases Society of America recommends starting antibiotics immediately if there are signs of hemodynamic instability or septic shock, immunocompromised state, suspected meningitis, or suspected cholangitis 4
Stable, immunocompetent patients without signs of sepsis or organ dysfunction can be observed for 1-2 hours before antibiotics are administered, but blood cultures should be obtained and close monitoring should be in place 4

For hypotension, initiate immediate fluid resuscitation with 250-500 mL crystalloid boluses, as recommended by the Society of Critical Care Medicine 1, 2, 4
Monitor vital signs every 4 hours, or every 2 hours if receiving pressors, and perform pulse oximetry every 4 hours, starting oxygen if saturation is less than 92% 1, 2
Strict intake and output monitoring every 8 hours, neurologic assessment every 8 hours, and serial lactate measurements in unstable patients should be performed to guide supportive care 1, 2, 4

For patients receiving IL-2 therapy, rigors typically occur 1-2 hours after each dose, followed by fever 1-2 hours later, and prophylactic acetaminophen and NSAIDs should be given before each dose 1, 2
If there is a recent travel history to endemic areas, immediately exclude malaria, dengue fever, enteric fever, and rickettsial diseases, and initiate empiric treatment for suspected life-threatening tropical infections with clinical instability while awaiting confirmatory testing 4