What are the recommendations for using Methohexitol (barbiturate) for sedation or anesthesia?

From the Guidelines

Methohexital is not recommended as a first-line agent for sedation or anesthesia due to its potential for respiratory depression and lack of superiority over other agents, as evidenced by a prospective, randomized comparison of methohexital and propofol for procedural sedation and analgesia in the ED, which found similar rates of respiratory depression for both agents 1.

Key Considerations

• Methohexital is a short-acting barbiturate that can be used for brief procedures requiring sedation or anesthesia, but its use should be carefully considered due to the potential risks.
• The onset of action is rapid (30-60 seconds) with a duration of 5-10 minutes, and intermittent boluses of 0.2-0.4 mg/kg can be given as needed for longer procedures.
• Patients should be monitored continuously for vital signs, oxygen saturation, and level of consciousness, and the drug should be reconstituted to a 1% solution (10 mg/mL) and administered slowly over 30-60 seconds to avoid respiratory depression and hypotension.

Recommendations

• The selection of methohexital should be individualized for each patient, taking into account the potential benefits and risks, as well as the availability of alternative agents with more favorable safety profiles 1.
• Patients with porphyria, uncontrolled seizure disorders, or hypersensitivity to barbiturates should not receive methohexital.
• Premedication with an anticholinergic agent may be beneficial to reduce secretions, and patients should not drive or make important decisions for 24 hours after administration.

Evidence-Based Practice

• The use of methohexital should be guided by evidence-based guidelines and institutional policies, which should include credentialing and verification of competency of providers, selection and preparation of patients, informed consent, equipment and monitoring requirements, staff training and competency verification, criteria for discharge, and continuous quality improvement 1.
• The choice of sedation agent should be based on the individual patient's needs and medical history, as well as the specific procedure being performed, and should take into account the potential risks and benefits of each agent.

From the FDA Drug Label

WARNINGS As with all potent anesthetic agents and adjuncts, BREVITAL should be used only in hospital or ambulatory care settings that provide for continuous monitoring of respiratory (e. g. pulse oximetry) and cardiac function. Maintenance of a patent airway and adequacy of ventilation must be ensured during induction and maintenance of anesthesia with methohexital sodium solution Prolonged administration may result in cumulative effects, including extended somnolence, protracted unconsciousness, and respiratory and cardiovascular depression.

The recommendations for using Methohexitol for sedation or anesthesia are to use it in a hospital or ambulatory care setting with continuous monitoring of respiratory and cardiac function. Maintenance of a patent airway and adequate ventilation is crucial. Additionally, prolonged administration should be avoided to prevent cumulative effects, including respiratory and cardiovascular depression 2.

• Key considerations:
  • Use in a setting with continuous monitoring
  • Maintain a patent airway and adequate ventilation
  • Avoid prolonged administration
  • Be aware of potential cumulative effects 2.

From the Research

Recommendations for Using Methohexitol

• Methohexital is a barbiturate that can be used for procedural sedation in the emergency department, with a mean dose of 1.43 mg/kg resulting in an 80.8% success rate with the first dose 3.
• The use of methohexital for sedation has been compared to other agents such as ketamine and propofol, with similar procedural success rates and adverse event rates 4.
• Methohexital has been used to control increased intracranial pressure in patients with severe brain damage, with a clear trend for decreasing ICP in patients with intracranial hypertension refractory to standard therapeutic measures 5.
• Methohexital has been compared to midazolam and propofol for sedation in ventilated intensive care patients, with a reduced incidence of delirium in patients sedated with methohexital 6.
• Methohexital has been used for sedation during electrical cardioversion, with a rapid anesthetic onset and recovery compared to midazolam 7.

Adverse Events and Complications

• Complications associated with methohexital use include oxygen desaturation, hypotension, hypoventilation, vomiting, tremor, and airway obstruction 3.
• Respiratory depression is a potential complication of methohexital use, although no incidence of respiratory depression was observed in one study 4.
• Methohexital can cause a decrease in cerebral perfusion pressure, although this was not significant in one study 5.

Dosage and Administration

• The mean dose of methohexital used for procedural sedation is 1.43 mg/kg 3.
• Methohexital can be administered as a continuous infusion in doses of 2-4-6 mg/kg body weight, depending on the ICP lowering effect 5.
• Methohexital can be titrated to effect, with a dose range of 0.5-2.0 mg/kg for sedation during electrical cardioversion 7.