title: Changes in the T-wave amplitude of ECG during isoflurane anaesthesia.
abstract: R/T-wave amplitude ratio of electrocardiogram (ECG), heart rate (HR) and systolic arterial pressure (SAP) were recorded in 15 patients awake, at 1 minimal alveolar concentration of isoflurane before and during surgery, and in deep anaesthesia (electroencephalogram burst suppression) during surgery. R/T-wave amplitude ratio and HR were sensitive to both surgery and changes in the level of isoflurane anaesthesia; induction of anaesthesia, skin incision and the rapid increase in the concentration of isoflurane all significantly decreased the T-wave amplitude, without influence on the R-wave. Changes in the T-wave amplitude correlated directly to HR. SAP increased at skin incision and decreased when the anaesthesia was deepened. The authors conclude that the R/T-wave amplitude ratio of ECG provides a reliable method for monitoring the sympathetic tone during isoflurane anaesthesia.
authors.affiliation: Department of Clinical Sciences, Tampere University Hospital, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Annila
authors.forename: V
authors.initials: V
authors.lastname: Jäntti
authors.forename: L
authors.initials: L
authors.lastname: Lindgren
authors.forename: A
authors.initials: A
authors.lastname: Yli-Hankala
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D062109:Dermatologic Surgical Procedures; D004562:Electrocardiography / Q000187:drug effects*; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007530:Isoflurane / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D013514:Surgical Procedures, Operative; D013997:Time Factors
chemical_list: D007530:Isoflurane