What is the management approach for postoperative tremors?

Management of Postoperative Tremors

Beta blockers are the first-line treatment for postoperative tremors, with meperidine as an effective alternative for severe cases due to its potent anti-shivering properties.

Causes and Assessment

Postoperative tremors (shivering) are common after surgery and can be caused by several factors:

• Pain can heighten sympathetic tone, leading to tremors and shivering 1
• Hypothermia is a primary trigger for postoperative shivering as the body attempts to generate heat 2
• Electrolyte abnormalities, particularly hypokalemia and hypomagnesemia, can contribute to tremors 1, 3
• Medication effects, including anesthesia emergence, can precipitate tremors 2

Initial Management Approach

Non-pharmacologic Interventions (First Steps)

• Implement skin counterwarming as the first measure to mitigate shivering, as each 4°C increase in mean skin temperature reduces the shivering response threshold 2
• Focus on warming extremities, particularly ears, palms, and soles, which can be quite effective 2
• Normalize electrolyte abnormalities, especially potassium and magnesium levels 3
• Address pain adequately, as it can exacerbate tremors through heightened sympathetic tone 1

Pharmacologic Management (First-Line)

• Beta blockers are the most effective first-line treatment for postoperative tremors, particularly for tremors due to heightened sympathetic tone 1, 3, 4
• For patients with heart failure with preserved ejection fraction (HFpEF), beta blockers or non-dihydropyridine calcium channel antagonists are recommended for rate control 2
• In the absence of pre-excitation, IV beta blockers are recommended to slow ventricular response in the acute setting 2

Management of Severe or Refractory Tremors

Second-Line Pharmacologic Options

• Meperidine (12.5-50 mg) is one of the most effective drugs for severe tremors as it both lowers the shivering threshold and suppresses shivering 2

  • Caution: Active metabolite associated with neurotoxicity and decreased seizure threshold 2

• Magnesium sulfate (2-4 g followed by 1 g/h infusion) can be used as a non-sedating adjunct, though it has modest clinical effect when used alone 2

• Acetaminophen can be used as a non-sedating adjunct but is typically insufficient to suppress clinically significant shivering when used alone 2

Severe Cases Requiring Aggressive Intervention

• Neuromuscular blockade (NMB) is the most effective abortive measure for severe, refractory shivering 2
  • Consider short-term NMB (one or two boluses of a longer-acting drug) to help rapidly achieve temperature control 2
  • Options include cisatracurium (0.1-0.2 mg/kg), atracurium (0.4-0.6 mg/kg), rocuronium (0.6-1 mg/kg), or vecuronium (0.1 mg/kg) 2
  • Monitor the degree of NMB using train-of-four testing when using continuous infusions 2

Special Considerations

Cardiac Patients

• For patients with atrial fibrillation after cardiac surgery, beta blockers are recommended as first-line treatment 2
• For patients with heart failure, a combination of digoxin and beta blocker is reasonable to control resting and exercise heart rate 2
• It is recommended to continue patients' usual treatment with calcium channel blockers, beta blockers, or angiotensin-converting enzyme inhibitors to decrease the incidence of postoperative atrial fibrillation 2

Common Pitfalls to Avoid

• Failure to recognize and treat underlying causes such as pain, hypoxemia, and electrolyte abnormalities 3
• Using digoxin as first-line therapy, which is less effective when adrenergic tone is high in the postoperative setting 2, 1, 3
• Neglecting to monitor patients continuously when initiating antiarrhythmic therapy 3
• Overlooking the potential for medication interactions in the postoperative setting 2

Monitoring During Treatment

• Continuous cardiac monitoring during treatment initiation, especially when using antiarrhythmic drugs 1, 3
• Regular assessment of vital signs and response to therapy 1
• Monitor for QT prolongation if using certain antiarrhythmic drugs 3
• For patients with implantable cardioverter-defibrillators (ICDs) who had preoperative reprogramming, continuous cardiac monitoring is essential until tachytherapy is reactivated 2