How should I manage an adult patient with sepsis who is hypothermic?

Management of Hypothermia in Sepsis

In adult patients with sepsis who are hypothermic (core temperature <36°C), you should actively rewarm the patient to achieve and maintain a core temperature between 36–37°C using passive and active warming techniques, as hypothermia in sepsis is associated with increased mortality and impaired immune function. 1, 2

Initial Assessment and Temperature Monitoring

• Measure core temperature immediately using a rectal, esophageal, or bladder thermometer—peripheral measurements are unreliable in shock states. 2
• Monitor temperature every 5 minutes during active rewarming until the patient reaches 36°C, then continue monitoring every 30–60 minutes. 2
• Recognize that hypothermia in sepsis indicates severe physiologic derangement and is often associated with profound tissue hypoperfusion, coagulopathy, and cardiovascular dysfunction. 1, 2

Rewarming Strategy Algorithm

Level 1: Passive and Basic Active Warming (All Hypothermic Septic Patients)

• Remove all wet clothing immediately and replace with warm, dry blankets or gowns. 2
• Apply forced-air warming blankets (e.g., Bair Hugger) set to 43°C over the torso and extremities. 2
• Infuse all IV crystalloids through a fluid warmer to deliver fluids at 39–41°C—cold fluids exacerbate hypothermia and coagulopathy. 2
• Administer warmed humidified oxygen (40–42°C) via ventilator circuit or high-flow nasal cannula to reduce respiratory heat loss. 2

Level 2: Advanced Active Warming (Temperature <35°C or Inadequate Response to Level 1)

• Initiate continuous arteriovenous rewarming (CAVR) if available: place percutaneous femoral arterial and venous catheters connected through a countercurrent fluid warmer, which reverses hypothermia in approximately 39 minutes versus 3.2 hours with standard rewarming. 3
• Consider warmed peritoneal or pleural lavage (43°C crystalloid) in patients with open abdominal or thoracic cavities during damage-control surgery. 2
• Use extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass for refractory hypothermia (<32°C) with cardiovascular collapse, though this is rarely required in sepsis. 2

Target Temperature and Stopping Criteria

• Rewarm to a minimum core temperature of 36°C before transferring the patient to another unit or reducing warming intensity. 2
• Stop active rewarming at 37°C—temperatures above this threshold are associated with poor outcomes and increased mortality in critically ill patients. 2, 4
• Maintain normothermia (36–37°C) throughout the sepsis resuscitation; avoid both hypothermia and hyperthermia. 1, 4

Concurrent Sepsis Management During Rewarming

• Administer IV broad-spectrum antibiotics within 1 hour of sepsis recognition, regardless of temperature—do not delay antimicrobials to achieve normothermia first. 5, 6, 7
• Give at least 30 mL/kg IV crystalloid within the first 3 hours for sepsis-induced hypoperfusion, using warmed fluids exclusively. 8, 5, 6
• Initiate norepinephrine if MAP remains <65 mmHg after initial fluid resuscitation, starting at 0.05–0.1 µg/kg/min. 8, 5, 6
• Measure serum lactate immediately and repeat within 6 hours if elevated, using lactate normalization as a resuscitation endpoint. 5, 6
• Identify and control the infection source within 12 hours through drainage, debridement, or device removal. 5

Physiologic Rationale for Rewarming in Sepsis

• Hypothermia impairs coagulation by reducing platelet function and clotting factor activity, which completely resolves with aggressive warming. 2
• Hypothermia increases oxygen demand through shivering and metabolic stress, worsening tissue hypoperfusion in septic shock. 4
• Hypothermia shifts the oxyhemoglobin dissociation curve leftward, impairing oxygen delivery to tissues already compromised by sepsis. 2
• Hypothermia depresses myocardial contractility and cardiac output, exacerbating the cardiovascular dysfunction of septic shock. 2, 4

Common Pitfalls to Avoid

• Do not use external cooling devices or cold fluids in hypothermic septic patients—this worsens outcomes. 1, 2
• Avoid shivering during rewarming by using sedation or neuromuscular blockade if necessary, as shivering dramatically increases oxygen consumption. 4
• Do not target temperatures >37°C—hyperthermia (>40°C) is harmful and should be treated, but moderate fever (37–39°C) may support immune function in sepsis. 4
• Do not delay antibiotics or source control to achieve normothermia—these interventions must proceed simultaneously. 5, 6
• Recognize that hypothermia in sepsis differs from trauma hypothermia—the underlying pathophysiology is distributive shock with impaired thermoregulation rather than environmental exposure. 1, 2

Monitoring Response to Rewarming

• Assess tissue perfusion markers during rewarming: capillary refill time <2 seconds, warm extremities, improved mental status, and urine output ≥0.5 mL/kg/h. 5, 7
• Monitor for coagulopathy reversal by checking PT/INR and platelet count as temperature normalizes. 2
• Watch for arrhythmias during rewarming, particularly atrial fibrillation, which may occur as core temperature rises. 2