Immediate Management of Involuntary Movements in a Sedated Patient on Propofol
Stop the propofol infusion immediately and assess for Propofol Infusion Syndrome (PRIS), as involuntary movements in a sedated cardiovascular patient on propofol may represent early neuromuscular manifestations of this potentially fatal complication. 1, 2
Immediate Assessment and Diagnostic Workup
Obtain urgent laboratory studies to evaluate for PRIS, including: 1, 2, 3
- Arterial blood gas (looking for metabolic acidosis with base excess >10 mmol/L)
- Serum creatine kinase (rhabdomyolysis marker)
- Serum triglycerides (hypertriglyceridemia)
- Serum potassium (hyperkalemia)
- Renal function tests (creatinine, BUN)
- Liver enzymes
- Serum lactate
- Troponin I (cardiac muscle injury)
- Urine myoglobin
Monitor continuously for cardiac manifestations including bradycardia, arrhythmias, hypotension with increasing vasopressor requirements, and signs of cardiac failure. 1, 4, 5
Risk Factor Assessment
Evaluate the patient's specific PRIS risk factors: 1, 2, 5
- Duration of propofol infusion (>48 hours significantly increases risk)
- Current infusion rate (>70 μg/kg/min is high risk, though PRIS can occur at rates as low as 1.9-2.6 mg/kg/hr)
- Concurrent catecholamine administration
- Concurrent corticosteroid use
- Acute neurological illness or inflammatory conditions
- Carbohydrate depletion states
Alternative Sedation Strategy
Transition immediately to dexmedetomidine-based sedation as the preferred alternative in cardiovascular patients: 6, 1
- Loading dose: 1 μg/kg over 10 minutes (only if hemodynamically stable)
- Maintenance infusion: 0.2-0.7 μg/kg/hr
- Monitor for bradycardia and hypotension (common side effects)
- Provides sedation without respiratory depression
- Lower delirium risk compared to benzodiazepines
If dexmedetomidine is contraindicated (severe bradycardia, heart block), consider: 6
- Midazolam: Loading 0.01-0.05 mg/kg, maintenance 0.02-0.1 mg/kg/hr
- Caution: Benzodiazepines are highly deliriogenic and cause delayed awakening, but provide reliable amnesia during neuromuscular blockade if needed
Maintain analgesic coverage throughout the transition: 6
- Continue or initiate fentanyl infusion: 25-300 μg/hr (0.5-5 μg/kg/hr)
- Propofol has no analgesic properties, so pain control must be addressed separately
Differential Diagnosis Considerations
Rule out other causes of involuntary movements in this clinical context: 6
Shivering (if patient underwent cardiac arrest or temperature management): 6
- Consider meperidine 12.5-50 mg (potent anti-shivering properties)
- Magnesium sulfate 2-4 g bolus, then 1 g/hr infusion
- Non-pharmacologic measures: surface counterwarming
Paradoxical agitation from sedatives: 6
- Can occur with benzodiazepines, phenobarbital, or neuroleptics
- More common in elderly patients
Seizure activity (propofol withdrawal can lower seizure threshold): 6
- Obtain EEG if available
- Consider antiepileptic therapy if seizures confirmed
Delirium with motor manifestations: 6
- If delirium suspected, consider low-dose haloperidol or levomepromazine
- Avoid increasing sedatives initially, as this can worsen delirium
Management of Confirmed PRIS
If PRIS is confirmed or highly suspected: 1, 2, 4
- Discontinue propofol immediately (already done)
- Provide aggressive supportive care:
- Hemodynamic support with vasopressors/inotropes as needed
- Correct metabolic acidosis with sodium bicarbonate
- Initiate renal replacement therapy for acute kidney injury
- Consider extracorporeal membrane oxygenation (ECMO) for refractory cardiac failure
- Mortality approaches 33% even with aggressive treatment
Critical Pitfalls to Avoid
Do not resume propofol even at lower doses once PRIS is suspected. 1, 2
Do not use rapid bolus dosing of alternative sedatives in cardiovascular patients, as this can cause severe hypotension and cardiac decompensation. 7
Do not delay switching sedatives if propofol has been running >48 hours at any dose, as PRIS prevention is far more effective than treatment. 1, 4
Do not forget to wean sedation gradually when transitioning—abrupt discontinuation causes anxiety, agitation, and ventilator dyssynchrony. 7
Do not assume movements are benign shivering without ruling out PRIS in any patient on prolonged propofol, especially those with cardiovascular disease, receiving catecholamines, or with acute neurological/inflammatory conditions. 1, 5