Ketamine infusions. Observations on technique, dosage and cardiovascular effects

Area of Science:

• Anesthesiology
• Pharmacology

Background:

• Ketamine is a dissociative anesthetic with a unique profile.
• Its use as a sole anesthetic agent requires careful management of side effects.
• Pre-operative medication can mitigate emergence phenomena.

Purpose of the Study:

• To evaluate the efficacy and safety of continuous ketamine infusion as a sole anesthetic.
• To analyze ketamine dosage requirements and cardiovascular effects.
• To identify optimal adjuncts and contraindications for this anesthetic technique.

Main Methods:

• Continuous ketamine infusion (1 mg/kg initial dose) in over 200 adult patients.
• Pre-operative administration of lorazepam (4 mg).
• Use with and without neuromuscular blocking agents and controlled ventilation.

Main Results:

• Ketamine infusion with lorazepam effectively managed anesthesia and reduced emergence sequelae.
• Pancuronium was associated with significant tachycardia and hypertension.
• Hypertonus was a primary concern in non-relaxant cases.
• Detailed analysis of ketamine dosage and cardiovascular effects provided recommendations.

Conclusions:

• Continuous ketamine infusion is a viable sole anesthetic in adults when combined with lorazepam.
• Careful selection of neuromuscular blocking agents and ventilation is crucial.
• Further research is needed in resource-limited settings lacking inhalation agents and sufficient anesthetists.