What is the recommended use and dosage of Atracurium (Atracurium besylate) for facilitating endotracheal intubation and skeletal muscle relaxation?

Atracurium Besylate for Endotracheal Intubation and Skeletal Muscle Relaxation

Atracurium besylate should be administered at a dose of 0.4 to 0.5 mg/kg intravenously for endotracheal intubation, with maintenance doses of 0.08 to 0.10 mg/kg every 15-25 minutes as needed for prolonged skeletal muscle relaxation. 1, 2

Standard Dosing Recommendations

Initial Dosing

• Initial dose: 0.4-0.5 mg/kg IV (1.7-2.2 times the ED95) 2
• Onset of action: 2-2.5 minutes for good to excellent intubation conditions 2
• Maximum neuromuscular block: 3-5 minutes after injection 2
• Duration of clinical effect: 20-35 minutes under balanced anesthesia 2

Maintenance Dosing

• Maintenance dose: 0.08-0.10 mg/kg IV 1, 2
• First maintenance dose timing: 20-45 minutes after initial dose 2
• Subsequent maintenance intervals: Every 15-25 minutes as needed 1, 2
• Higher doses (up to 0.2 mg/kg) allow longer intervals between maintenance doses 2

Special Population Considerations

Cardiovascular Disease Patients

• Reduced initial dose: 0.3-0.4 mg/kg IV 1, 2
• Administration method: Give slowly or in divided doses over one minute 1, 2

Pediatric Patients

• Children ≥2 years: Same as adult dosing 2
• Infants (1 month to 2 years): 0.3-0.4 mg/kg under halothane anesthesia 2
• Note: Maintenance doses may be required more frequently in pediatric patients 2

Effect of Inhalational Anesthetics

• Isoflurane/enflurane: Potentiate atracurium by approximately 35% 2
  • Reduce initial dose to 0.25-0.35 mg/kg when administered under steady-state conditions 2
• Halothane: Marginal potentiation (approximately 20%) 2
  • Smaller dosage reductions may be considered 2

Administration Guidelines

• Must be administered after unconsciousness is induced 2
• Administer intravenously only (NOT intramuscularly) 2
• Do not mix with alkaline solutions (e.g., barbiturate solutions) in the same syringe 2
• Do not administer simultaneously through the same needle with alkaline solutions 2

Monitoring Recommendations

• Peripheral nerve stimulation monitoring is strongly recommended to: 1, 2
  • Minimize risk of overdosage or underdosage
  • Assess recovery
  • Guide timing of maintenance doses
  • Determine optimal timing for reversal agents
• Corrugator supercilii muscle is the recommended monitoring site 1

Reversal of Neuromuscular Blockade

• Reversal can be achieved with anticholinesterase agents: 2
  • Neostigmine
  • Edrophonium
  • Pyridostigmine
• Always administer with anticholinergic agents (atropine or glycopyrrolate) 2
• Timing of reversal:
  • Attempt approximately 20-35 minutes after initial dose of 0.4-0.5 mg/kg 2
  • Or 10-30 minutes after a maintenance dose of 0.08-0.10 mg/kg 2
  • When recovery of muscle twitch has started 2
• Complete reversal usually attained within 8-10 minutes of administering reversing agents 2

Clinical Pearls and Caveats

• Atracurium undergoes Hofmann elimination and ester hydrolysis, making it suitable for patients with renal or hepatic impairment 2
• Duration of neuromuscular block does not correlate with plasma pseudocholinesterase levels 2
• Atracurium is a less potent histamine releaser than other non-depolarizing agents like d-tubocurarine or metocurine 2
• Rare instances of breathing difficulties possibly related to incomplete reversal have been reported 2
• The tendency for residual neuromuscular block increases if:
  • Reversal is attempted at deep levels of block
  • Inadequate doses of reversal agents are employed 2

By following these dosing and administration guidelines, atracurium besylate can provide effective skeletal muscle relaxation for endotracheal intubation and surgical procedures while minimizing potential complications.