Termination of anaesthesia--do we pay enough attention to its consequences? Haemodynamic studies following the use of piritramide, flunitrazepam and nitrous oxide anaesthesia for open heart surgery.
After completion of coronary or valve replacement surgery the haemodynamic changes due to cessation of nitrous oxide were measured. Seventy-four patients received piritramide-nitrous oxide anaesthesia. In 20 patients nitrous oxide was continued after operation and no marked haemodynamic changes occurred. However, when nitrous oxide was discontinued immediately after the operation (n=30) a significant rise in systolic arterial pressure (108+/-15 to 153+/-30 mm Hg), systolic pulmonary artery pressure (35+/-9 to 40+/-16 mm Hg), systemic vascular resistance (111 +/-26 to 148+/-44 MN.s.m-5) and rate pressure product (9,600+/-1,600 to 14,300+/-4,000) occurred. Heart rate (89+/-11 min-1), left artrial pressure (13+/---4 mm Hg) CO2 minute production (125+/-19 ml. min-1.m-2) and cardiac index (2.5+/-0.61.min-1.m-2) rose only moderately. When additional flunisternal closure to 24 patients, marked haemodynamic changes were still noted after N2O withdrawal, even though anaesthesia was prolonged. The sudden rise of arterial pressure and vascular resistance implies risks to patients with myoicardial or coronary insufficiency, therefore close monitoring is necessary, when nitrous oxide has to be stopped, to enable undelayed antihypertensive therapy.
D000328:Adult; D000758:Anesthesia; D014151:Anti-Anxiety Agents; D001794:Blood Pressure / Q000187:drug effects; D006348:Cardiac Surgical Procedures / Q000379:methods; D001026:Coronary Artery Bypass; D005445:Flunitrazepam; D006339:Heart Rate / Q000187:drug effects; D006350:Heart Valve Prosthesis; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000209:etiology; D007540:Isonipecotic Acids; D009609:Nitrous Oxide; D010892:Pirinitramide; D011651:Pulmonary Artery
D014151:Anti-Anxiety Agents; D007540:Isonipecotic Acids; D010892:Pirinitramide; D005445:Flunitrazepam; D009609:Nitrous Oxide