Synergism between atracurium and vecuronium in infants and children during nitrous oxide-oxygen-alfentanil anaesthesia.

This study was undertaken to see if infants are more sensitive than children to a combination of atracurium and vecuronium in an equipotent dose ratio: (microgram: microgram) 5:1 in infants and 4:1 in children. We studied 15 infants (1-11 months old) and 15 children (3-10 yr old) during nitrous oxide-oxygen-alfentanil anaesthesia. Neuromuscular function was recorded by adductor pollicis EMG. An individual dose-response curve of the atracurium-vecuronium combination was determined for every patient and its potency compared with that of the parent agents alone. The combination was significantly more potent than one parent agent, both in infants (P < 0.01) and in children (P < 0.0001). However, infants were less sensitive than children to synergism produced by the atracurium-vecuronium combination: if the ED50 dose of the parent agent is defined as one dose equivalent, then the mean ED50 doses of the combination were 0.81 (SEM 0.05) and 0.64 (0.03) dose equivalents in infants and children, respectively (P < 0.01). We suggest that an interaction between two binding sites of competitive neuromuscular blocking agents in postsynaptic acetylcholine receptors may explain both the synergism and sensitivity of infants to non-depolarizing neuromuscular blocking agents.

[1]  T. Taivainen,et al.  Synergism Between Atracurium and Vecuronium with Mivacurium , 1995 .

[2]  D. E. Martin,et al.  The Onset and Duration of Neuromuscular Blockade Using Combinations of Atracurium and Vecuronium , 1991, Anaesthesia and intensive care.

[3]  O. Meretoja.  Neuromuscular Blocking Agents in Paediatric Patients: Influence of Age on the Response , 1990, Anaesthesia and intensive care.

[4]  O. Meretoja,et al.  Two-dose technique to create an individual dose-response curve for atracurium. , 1989, Anesthesiology.

[5]  I. Kalli.  Effect of surface electrode positioning on the compound action potential evoked by ulnar nerve stimulation in anaesthetized infants and children. , 1989, British journal of anaesthesia.

[6]  O. Meretoja,et al.  Influence of age on the dose‐response relationship of atracurium in paediatric patients , 1988, Acta anaesthesiologica Scandinavica.

[7]  M. Schork,et al.  Interactions of Vecuronium and Atracurium in an In Vitro Nerve‐Muscle Preparation , 1988, Anesthesia and analgesia.

[8]  P. Neuvonen,et al.  Age‐Dependence of the Dose‐Response Curve of Vecuronium in Pediatric Patients during Balanced Anesthesia , 1988, Anesthesia and analgesia.

[9]  N. Goudsouzian,et al.  The Infant and the Myoneural Junction , 1986, Anesthesia and analgesia.

[10]  D. Phil.,et al.  Interaction among Agents that Block End‐plate Depolarization Competitively , 1985, Anesthesiology.

[11]  D. Stanski,et al.  Pharmacokinetics and Pharmacodynamics of d‐Tubocurarine in Infants, Children, and Adults , 1982, Anesthesiology.

[12]  P. Taylor,et al.  Relationship between reversible antagonist occupancy and the functional capacity of the acetylcholine receptor. , 1981, The Journal of biological chemistry.

[13]  H. H. Ali,et al.  Potentiation of Neuromuscular Blockade in Man Produced by Combinations of Pancuronium and Metocurine or Pancuronium and d‐Tubocurarine , 1980, Anesthesia and analgesia.