Antagonism of neuromuscular blockade but not muscle relaxation affects depth of anaesthesia

Br J Anaesth. 2005 Jun;94(6):742-7. doi: 10.1093/bja/aei120. Epub 2005 Mar 18.

Abstract

Background: Conflicting effects of neuromuscular blocking drugs and anticholinesterases on depth of anaesthesia have been reported. Therefore we evaluated the effect of atracurium and neostigmine on bispectral index (BIS) and middle-latency auditory evoked potentials (AAI).

Methods: We studied 40 patients (ASA I-II) aged 18-69 yr. General anaesthesia consisted of propofol and remifentanil by target-controlled infusion and neuromuscular function was monitored by electromyography. When BIS reached stable values, patients were randomly assigned to one of two groups. Group 1 received atracurium 0.4 mg kg(-1) and, 5 min later, the same volume of NaCl 0.9%; group 2 received saline first and then atracurium. When the first twitch of a train of four reached 10% of control intensity, patients were again randomized: one group (N) received neostigmine 0.04 mg kg(-1) and glycopyrrolate 0.01 mg kg(-1), and the control group (G) received only glycopyrrolate.

Results: Injection of atracurium or NaCl 0.9% had no effect on BIS or AAI. After neostigmine-glycopyrrolate, BIS and AAI increased significantly (mean maximal change of BIS 7.1 [SD 7.5], P<0.001; mean maximal change of AAI 9.7 [10.5], P<0.001). When glycopyrrolate was injected alone BIS and AAI also increased (mean maximal change of BIS 2.2 [3.4], P=0.008; mean maximal change of AAI 3.5 [5.7], P=0.012), but this increase was significantly less than in group N (P=0.012 for BIS; P=0.027 for AAI).

Conclusion: These data suggest that neostigmine alters the state of propofol-remifentanil anaesthesia and may enhance recovery.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Anesthetics, Combined / pharmacology
  • Anesthetics, Intravenous / pharmacology*
  • Atracurium / pharmacology
  • Blood Pressure / drug effects
  • Cholinesterase Inhibitors / pharmacology*
  • Double-Blind Method
  • Drug Interactions
  • Electroencephalography / drug effects
  • Evoked Potentials, Auditory / drug effects*
  • Female
  • Heart Rate / drug effects
  • Humans
  • Male
  • Middle Aged
  • Monitoring, Intraoperative / methods
  • Muscle Relaxation / drug effects*
  • Neostigmine / pharmacology
  • Neuromuscular Blockade*
  • Neuromuscular Nondepolarizing Agents / pharmacology
  • Piperidines / pharmacology
  • Propofol / pharmacology
  • Prospective Studies
  • Remifentanil

Substances

  • Anesthetics, Combined
  • Anesthetics, Intravenous
  • Cholinesterase Inhibitors
  • Neuromuscular Nondepolarizing Agents
  • Piperidines
  • Atracurium
  • Neostigmine
  • Remifentanil
  • Propofol