title: Circulatory responses to laryngeal mask airway insertion or tracheal intubation in normotensive and hypertensive patients.
abstract: The effects of laryngeal mask airway (LMA) insertion and tracheal intubation on circulatory responses were studied in normotensive (n = 24) and hypertensive (n = 22) patients. In a randomized, double-blind manner, LMA insertion or tracheal intubation was performed after induction of anaesthesia with thiopentone and muscle relaxation with succinylcholine. In both normotensive and hypertensive patients, heart rate (HR), mean arterial pressure (MAP) and rate-pressure product increased after tracheal intubation or LMA insertion compared with baseline (P < 0.05). The haemodynamic changes were greater after intubation than after LMA insertion (P < 0.05). Following intubation of the trachea or insertion of the LMA, HR increased more markedly in hypertensive patients than in normotensive patients (P < 0.05). Plasma adrenaline and noradrenaline concentrations after tracheal intubation or LMA insertion increased compared with baseline values (P < 0.05) in normotensive and hypertensive patients. The increase in noradrenaline concentration after tracheal intubation was greater than that after LMA insertion (P < 0.05). No patient revealed ECG evidence of myocardial ischaemia. We conclude that insertion of LMA is associated with less circulatory responses than tracheal intubation in both normotensive and hypertensive patients.
authors.affiliation: Department of Anaesthesiology, Toride Kyodo General Hospital, Ibaraki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Toyooka
mesh_terms: D000328:Adult; D000368:Aged; D000771:Anesthesia, Intravenous; D001794:Blood Pressure / Q000502:physiology*; D005117:Cardiac Complexes, Premature / Q000209:etiology; D004311:Double-Blind Method; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007442:Intubation, Intratracheal / Q000295:instrumentation; D017214:Laryngeal Masks; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D009469:Neuromuscular Junction / Q000187:drug effects; D009638:Norepinephrine / Q000097:blood; D013390:Succinylcholine / Q000008:administration & dosage; D013874:Thiopental / Q000008:administration & dosage; D018754:Ventricular Dysfunction / Q000209:etiology
chemical_list: D013390:Succinylcholine; D013874:Thiopental; D009638:Norepinephrine; D004837:Epinephrine