Canadian Anaesthetists’ Society Journal

, Volume 26, Issue 5, pp 386–393 | Cite as

Awareness, muscle relaxants and balanced anaesthesia

  • Jacob Mainzer


The incidence of awareness during insufficient anaesthesia is reported to be one per cent. It is usually due to the use of muscle relaxants, a balanced technique and the lightest possible depth of anaesthesia. Increased incidences were noted in open-heart surgery, during intubation-endoscopy procedures and in caesarean delivery patients.

Experiences of awareness are disturbing to patients, who are usually benefited by a sympathetic and forthright explanation of the event. Fourteen representative cases of the problem are reported.

Since no adequate sign or test exists for detection of awareness during very light anaesthesia or with associated paralysis, more meticulous attention is required in using relaxants or the balanced technique. Greater anaesthetic supplementation and reduction in the use of relaxants are recommended to halt the recurrence of this most serious anaesthetic problem.


Morphine Nitrous Oxide Succinylcholine Thiopentone Meperidine 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Le maintien de la conscience au cours ďanesthésies de profondeur insuffisante est de ľordre ďun pourcent. Cette complication survient le plus souvent avec les techniques ďanesthésie balancée alors que ľon utilise des curarisants tout en maintenant le niveau ďanesthésie le plus léger possible. Les situations où ľon est le plus susceptible de rencontrer le phénomène sont le moment de ľintubation endotrachéale et les procédures endoscopiques en général, ainsi que la chirurgie cardiaque et les accouchements par césarienne.

C’est une expérience traumatique pour les malades. Il est généralement préférable de leur fournir une explication franche du phénomène tout en adoptant une attitude sympathique.

Comme il n’existe pas de signes permettant de détecter que ľétat de conscience persiste au cours ďanesthésie légère avec curarisation, il faut être très conscient de ce danger, et utiliser les curares et ľanesthésie balancée avec grande attention. Il est recommandable ďutiliser une anesthésie plus profonde et moins de relaxants musculaires afin ďéliminer ce problème sérieux.

Les auteurs rapportent quatorze cas du genre pour illustrer leur présentation.


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© Canadian Anesthesiologists 1979

Authors and Affiliations

  • Jacob Mainzer
    • 1
    • 2
  1. 1.Presbyterian Medical CenterAlbuquerqueUSA
  2. 2.Anesthesiology and History of MedicineUniversity of New Mexico School of MedicineAlbuquerque

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