What is the appropriate use and dosage of atracurium (Atracurium besylate) for muscle relaxation in general anesthesia?

Atracurium for Muscle Relaxation in General Anesthesia

Atracurium besylate at a dose of 0.4 to 0.5 mg/kg is recommended as the standard initial dose for muscle relaxation during general anesthesia in most adult patients, providing optimal intubation conditions and adequate surgical relaxation for 20-35 minutes under balanced anesthesia. 1

Dosing Recommendations

Standard Dosing for Adults

• Initial dose: 0.4-0.5 mg/kg IV (1.7-2.2 times ED95) for most patients 1
• Onset of action: Good to excellent intubation conditions within 2-2.5 minutes 1, 2
• Maximum neuromuscular blockade: Achieved approximately 3-5 minutes after injection 1
• Duration: 20-35 minutes of clinically required neuromuscular block under balanced anesthesia 1
• Recovery: 25% recovery at 35-45 minutes, 95% complete recovery at approximately 60 minutes 1

Maintenance Dosing

• Maintenance doses: 0.08-0.10 mg/kg IV 1
• Timing: First maintenance dose typically required 20-45 minutes after initial injection 1
• Interval: Maintenance doses can be administered every 15-25 minutes under balanced anesthesia 1
• Higher maintenance doses (up to 0.2 mg/kg) allow for longer dosing intervals 1

Special Populations and Situations

Patients with Cardiovascular Disease or Risk of Histamine Release

• Reduced initial dose: 0.3-0.4 mg/kg IV 1
• Administration technique: Give slowly or in divided doses over one minute 1

Patients Under Inhalational Anesthesia

• With isoflurane or enflurane: Reduce initial dose by approximately one-third (0.25-0.35 mg/kg) 1
• With halothane: Smaller dose reductions may be considered (approximately 20% potentiation) 1

Pediatric Patients

• Children ≥2 years: Same dosing as adults 1
• Infants (1 month to 2 years): 0.3-0.4 mg/kg under halothane anesthesia 1
• Maintenance doses may be required more frequently in infants and children than in adults 1

Special Clinical Scenarios

• For airway obstruction related to supraglottic devices: 0.1-0.2 mg/kg if depth of anesthesia is adequate 3
• After succinylcholine for intubation: Reduced dose of 0.3-0.4 mg/kg recommended 1
• For obese patients: Dosing based on ideal body weight rather than total body weight provides more predictable relaxation profile 4

Continuous Infusion

• Initial infusion rate: 9-10 mcg/kg/min to counteract spontaneous recovery from bolus dose 1
• Maintenance rate: 5-9 mcg/kg/min to maintain 89-99% neuromuscular block 1
• Range: Some patients may require 2-15 mcg/kg/min 1
• With inhalational anesthetics: Reduce infusion rate by approximately one-third with enflurane or isoflurane 1

Monitoring and Reversal

• Monitoring: Use of peripheral nerve stimulator is recommended for optimal dosing 1
• Monitoring site: The corrugator supercilii muscle is preferred due to its sensitivity to muscle relaxants and kinetics comparable to laryngeal muscle 3
• Reversal: Prompt and adequate reversal with neostigmine has been demonstrated 2

Clinical Applications

Surgical Procedures

• Recommended for abdominal laparotomy or laparoscopy surgery (Grade 1+ recommendation) 3
• Probably recommended for ENT laser surgery (Grade 2+ recommendation) 3

Special Considerations

• Renal/hepatic failure: Atracurium is probably recommended over other muscle relaxants due to its organ-independent elimination (Grade 2+ recommendation) 3
• No need to modify initial dose in renal/hepatic failure patients 3
• For outpatient procedures: Smaller doses (0.2 mg/kg) may be used with longer waiting time before intubation (6 minutes) but with spontaneous reversal within 20-30 minutes 5
• For emergency rapid sequence induction: Higher doses (0.75-1 mg/kg) can provide acceptable intubation conditions within one minute 6

Important Caveats

• Administer intravenously only; intramuscular administration is not recommended 1
• Do not mix with alkaline solutions such as barbiturate solutions 1
• Patients with neuromuscular disease may require significant dose reductions (up to 57% less than normal dose) 7
• Atracurium is potentiated by inhalational anesthetics, requiring dose adjustments 1
• Intraoperative monitoring of neuromuscular blockade is recommended (Grade 1+ recommendation) 3