Meperidine for Treatment of Shivering After Spinal Anesthesia
Meperidine (Demerol) at doses of 25-50 mg IV is the most effective pharmacologic agent for treating established shivering after spinal anesthesia, stopping shivering in nearly 100% of patients within 5 minutes. 1, 2
Why Meperidine is Superior
Meperidine is approximately 2,800 times more effective at inhibiting shivering than would be predicted by its analgesic potency alone, working through unique mechanisms beyond simple opioid analgesia that directly suppress the shivering threshold. 2
The American Society of Anesthesiologists explicitly recommends meperidine as the preferred agent for treating patient shivering during emergence and recovery, noting it is more effective than other opioid agonists or agonist-antagonists. 1
Among all opioid analgesics, meperidine uniquely both lowers the shivering threshold and directly suppresses shivering through non-analgesic mechanisms. 2
Dosing and Administration
Administer 25-50 mg IV for established shivering, with effect typically occurring within 5 minutes. 1, 2
For prevention rather than treatment, 25 mg IM given 15 minutes before spinal anesthesia reduces shivering incidence from 56.7% to 10%. 3
Intrathecal meperidine at 0.2 mg/kg added to spinal anesthetic reduces shivering incidence from 56.7% to 16.7%. 4
Important Safety Considerations
Exercise caution in patients at risk for seizures, as meperidine may aggravate preexisting convulsions or cause seizures if doses are escalated substantially. 5
Use with caution in patients with supraventricular tachycardias due to possible vagolytic action that may increase ventricular response rate. 5
Meperidine should be used cautiously in patients with sickle cell anemia, as shivering itself can precipitate sickling crisis. 5, 6
All opioids and sedatives blunt shivering at the expense of sedation and potential hemodynamic effects. 2
Alternative Agents (When Meperidine is Contraindicated)
If meperidine cannot be used, consider these alternatives in descending order of effectiveness:
Nefopam 0.15 mg/kg IV has comparable anti-shivering efficacy to meperidine with more stable hemodynamics, though injection pain occurs in 15.6% of patients. 7
Ketamine 0.25 mg/kg IV reduces shivering incidence to 10% (compared to 56.7% with placebo), though it causes mild to moderate sedation. 8
Tramadol 0.5 mg/kg IV reduces shivering incidence to 10%, with mild to moderate sedation as the main side effect. 8
Magnesium sulfate and acetaminophen are safe adjuncts with favorable side effect profiles, but when used alone are typically insufficient to suppress clinically significant shivering and should be part of multimodal therapy rather than monotherapy. 2
Critical Clinical Pitfall
Do not assume shivering is benign or self-limited—it indicates failed thermoregulation and doubles metabolic rate while nearly tripling oxygen consumption, which can trigger demand ischemia in vulnerable patients with cardiovascular disease. 6, 9 The key error is treating shivering reactively rather than implementing active warming measures prophylactically. 6
When Pharmacologic Approaches Fail
Neuromuscular blockade is the most effective abortive measure for refractory shivering when all pharmacologic approaches fail, particularly appropriate when active temperature management is expected to be transient. 2
However, the primary treatment for hypothermia-induced shivering should be rewarming with forced-air warming devices, not just pharmacologic suppression of the shivering response. 1