Abstract
During emergence from anaesthesia, transient neurological signs that would usually be considered pathological may appear. The objective of this randomized, patient (n = 30) and observerblinded study was to compare prospectively the incidence and duration of postanaesthetic neurological abnormalities in healthy patients undergoing minor elective procedures following thiopentone and succinylcholine induction, and enflurane-N2O or isoflurane- N2O anaesthesia. Patients were studied for 60 min after anaesthesia. Arousal state, muscle tone,deep tendon reflexes, plantar reflex, sustained clonus, shivering, intense muscular spasticity and temperature were assessed. Results of neurological examination were correlated with the patient’s state of arousal. Transient emergent neurological abnormalities occurred more frequently following enflurane-N2O anaesthesia than isoflurane N2O anaesthesia. This was statistically significant (P < 0.05) for quadriceps hyperreflexia, upgoing toes (positive Babinski reflex) and intense muscular spasticity. Neurological abnormalities occurred most commonly 5– 20 min after anaesthesia and all abnormalities resolved within 60 min. Following enflurane anaesthesia, as patients became more alert the incidence of abnormalities declined, while the arousal state did not affect the incidence of abnormalities after isoflurane. There was no significant difference between axillary temperatures of those patients who shivered and those who did not. In conclusion, temporary emergent neurological abnormalities occurred more often following enflurane- N2O than after isoflurane- N2O anaesthesia.
Résumé
A la fin de l’anesthésie, il est possible d’observer des signes neurologiques anormaux durant la phase d’émergence. Lors d’interventions mineures et apres une induction au thiopental el succinylcholine, nous avons randomisé 30 patients quant à l’anesthésique à employer en sus du N2O, soit l’enflurane ou l’isoflurane. Nous avons demandé à une observateur neutre de mesurer la fréquence et la durée des anomalies neurologiques à l’émergence. Pendant 60 minutes, il évaluait la température, le tonus musculaire, les réflexes tendineux et plantaires et notait la présence éventuelle d’ un clonus soutenu, de tremblements, de spasticité musculaire, le tout, en parallèle avec le niveau de conscience. L’hyperréflexie quadricipitale, la spasticité intense et un réflexe plantaire en extension (Babinski positif) sont survenus plus frequemment avec l’ enflurane- N2O qu’avec l’isoflurane -N2O (P < 0,05). Les anomalies neurologiques survenaient surtout entre 5 à 20 min après la fin de l’anesthésie et s’estompaient en deçà d’une heure. Dans le groupe enflurane- N2O, les anomalies disparaissaient à mesure que s’améliorait le niveau de conscience des patients mais cette relation n’était pas manifeste dans le groupe isoflurane- N2O. Par ailleurs, la température axillaire était la même, que les patients tremblent ou pas. La combinaison enflurane- N2O entraîne donc plus d’anomalies neurologiques transitoires à l’émergence que l’ isoflurane- N2O.
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McCulloch, P.R., Milne, B. Neurological phenomena during emergence from enflurane or isoflurane anaesthesia. Can J Anaesth 37, 739–742 (1990). https://doi.org/10.1007/BF03006531
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DOI: https://doi.org/10.1007/BF03006531