I.V. practolol during microlaryngoscopy. Effect on arterial pressure, heart rate, blood glucose and lipolysis

Twenty-five patients undergoing microlaryngoscopy were anaesthetized with thiopentone and nitrous oxide with suxamethonium as a muscle relaxant. Thirteen received practolol 0.4 mg kg-1 and atropine 1.5 mg i.v. shortly before anaesthesia. During anaesthesia practolol 0.2 mg kg-1 was given. Twelve (control) received atropine 0.5 mg before anaesthesia. Practolol reduced the frequency of tachycardia and arrhythmia. The treatment group had a greater reduction in systolic arterial pressure during induction. The hypertensive response to laryngoscopy was not significantly attenuated by practolol. A weak hyperglycaemic response to microlaryngoscopy was not affected, nor was the plasma concentration of glycerol.