What is the management approach for an adult patient with no specified medical history experiencing shivering?

Management of Shivering in Adult Patients

Begin with skin counterwarming of extremities (ears, palms, soles) as the first-line intervention, followed immediately by meperidine 25-50 mg IV if shivering persists, as this stops shivering in nearly 100% of patients within 5 minutes. 1, 2

Initial Assessment

Before treating shivering, rapidly assess the underlying cause:

• Measure core temperature to differentiate hypothermic (most common) from normothermic shivering 2
• Check for infection signs if temperature ≥38.0°C: obtain blood cultures, assess wound sites, respiratory status, and IV cannula sites for phlebitis 2, 3
• Evaluate pain control, as inadequate analgesia commonly manifests as shivering 2
• Consider medication effects, particularly reduction in sedatives that were suppressing the shivering response 2

Stepwise Treatment Algorithm

Step 1: Non-Pharmacologic Interventions (Implement Immediately)

• Surface counterwarming reduces the shivering threshold by approximately 4°C for each degree increase in mean skin temperature 1, 4
• Warm the extremities (ears, palms, soles) specifically, as this is more effective than total body warming in certain cases 1
• Use forced-air warming devices for hypothermic patients 2
• Administer warmed IV fluids if the patient is receiving fluid resuscitation 2, 4
• Ensure adequate ambient room temperature 2

Step 2: First-Line Pharmacologic Therapy

Meperidine is the drug of choice for established shivering:

• Dose: 25-50 mg IV stops shivering in nearly 100% of patients within 5 minutes 1, 2, 4
• Meperidine is approximately 2,800 times more effective at inhibiting shivering than predicted by its analgesic potency alone, uniquely both lowering the shivering threshold and directly suppressing shivering 4, 3
• Caution: Exercise care in patients at risk for seizures or those not continuously monitored 1

Step 3: Adjunctive Non-Sedating Agents

These agents have favorable safety profiles but are insufficient as monotherapy for clinically significant shivering:

• Acetaminophen as an antipyretic adjunct 1
• Magnesium sulfate (2-4 g bolus, then 1 g/h infusion) maintaining serum levels below 4 mg/dL 1, 4
• NSAIDs (ibuprofen) for pain-related or fever-related shivering 2, 3

Step 4: Alternative Sedative/Analgesic Approach

If meperidine is contraindicated or unavailable:

• Moderate-dose continuous opioid infusion (fentanyl or hydromorphone) 4
• Add short-acting sedative (dexmedetomidine or propofol infusion) titrated to minimum dose that suppresses shivering 4
• Note: All opioids and sedatives blunt shivering at the expense of sedation and potential hemodynamic effects 1

Step 5: Enhanced Combination Therapy

For refractory cases requiring aggressive temperature management:

• Meperidine combined with high-dose buspirone (30 mg) can reduce the shivering threshold to as low as 33°C 1, 4
• Caution: This combination lowers seizure threshold and requires continuous monitoring 1

Step 6: Last Resort - Neuromuscular Blockade

Neuromuscular blockade (NMB) is the most effective abortive measure for refractory shivering when pharmacologic approaches fail:

• Cisatracurium (0.1-0.2 mg/kg bolus, then 0.5-10 μg/kg/min infusion) is preferred due to non-enzymatic plasma degradation 4
• Use short-term NMB (one or two boluses) to rapidly achieve control during acute phases 1
• Titrate to minimum dose that suppresses shivering rather than complete paralysis 1
• Critical: Never administer NMB without adequate sedation, as this risks patient awareness 3

Context-Specific Considerations

Postoperative Shivering (Day 2)

• Delayed hypothermia can occur due to heat redistribution from core to periphery even on postoperative day 2 2
• Early infection (respiratory, wound) commonly presents with temperature spikes and shivering on day 2 2
• Ensure regular scheduled pain medication rather than as-needed administration 2

Infection-Related Shivering

• Obtain blood cultures if temperature ≥38.0°C 2, 3
• Initiate empiric antibiotics if sepsis is suspected 1, 4
• Provide supportive care including hydration and oxygenation 2

High-Risk Populations

Shivering doubles metabolic rate and nearly triples oxygen consumption, creating significant energy supply-demand mismatch:

• Cardiovascular compromise: Aggressive shivering control prevents cardiovascular decompensation 3
• Neurologic injury: Shivering reduces brain tissue oxygenation and causes cerebral metabolic stress, potentially worsening secondary brain injury 3
• Sickle cell disease: Particular attention required as shivering can precipitate sickling crisis 2

Critical Pitfalls to Avoid

• Do not rely on acetaminophen or magnesium alone for clinically significant shivering—these are adjuncts only and insufficient as monotherapy 4, 3
• Do not use propofol or dexmedetomidine as first-line agents in hemodynamically unstable patients due to hypotension risk 4
• Do not administer neuromuscular blockers without adequate sedation, as this risks patient awareness and does not address central thermoregulatory drive 3
• Do not ignore shivering in neurologically injured patients, as it can worsen secondary brain injury through increased metabolic demand 3
• Do not overlook infection as a concurrent cause—shivering with fever warrants prompt evaluation for sepsis 1, 4

Physiologic Rationale

Understanding why aggressive shivering control matters:

• Metabolic toll is profound: Shivering doubles metabolic rate with high muscle mass and nearly triples oxygen consumption 1
• Bioenergetic failure risk: Elevated metabolic expenditure can trigger demand cerebral ischemia and significant mismatch in energy supply-demand to the brain 1
• Thermoregulatory mechanism: Shivering is triggered by the preoptic hypothalamus when core temperature falls below threshold (usually 35.5-36°C) 1