Clinical experience with atracurium during prolonged anaesthesia

Area of Science:

• Anesthesiology
• Pharmacology
• Clinical Medicine

Background:

• Atracurium is a neuromuscular blocking agent used in anesthesia.
• Narcotic-based anesthesia is common, but its interaction with neuromuscular blockers needs study.
• Isoflurane is an inhalation anesthetic agent.

Purpose of the Study:

• To investigate the pharmacodynamic effects of repeated atracurium administration.
• To assess the impact of isoflurane on atracurium's duration of effect and recovery time.
• To determine if isoflurane alters the required maintenance doses of atracurium.

Main Methods:

• Twenty-two patients undergoing surgery received narcotic-based anesthesia.
• A control group received only narcotic-based anesthesia.
• An experimental group received narcotic-based anesthesia with 0.5% isoflurane.
• Neuromuscular blockade was monitored using train-of-four (TOF) stimulation of the adductor pollicis muscle.
• Atracurium doses (0.5 mg/kg bolus, 0.2 mg/kg maintenance) and recovery times were recorded.

Main Results:

• Repeated atracurium doses showed consistent intervals between maintenance requirements for individual patients.
• In the isoflurane group, the mean duration of atracurium effect increased significantly (36.1 to 42.2 minutes, P<0.05).
• Recovery times from neuromuscular blockade remained unchanged with the addition of isoflurane.

Conclusions:

• During narcotic-based anesthesia, patients exhibit predictable intervals for atracurium maintenance doses.
• Adding 0.5% isoflurane moderately prolongs the duration of atracurium's neuromuscular blocking effect.
• Isoflurane does not significantly alter the recovery time from atracurium-induced neuromuscular blockade.