pancuronium and Mitral-Valve-Stenosis

The hemodynamic effects of three nondepolarizing skeletal muscle relaxant drug regimens were compared during the induction of general anesthesia in 64 patients with valvular heart disease using a double-blind protocol. Patients were first stratified according to primary valvular defect (aortic stenosis, aortic regurgitation, mitral stenosis, or mitral regurgitation). Next, patients were randomly allocated to a drug group, either group A (atracurium), group V (vecuronium), or group MP (metocurine plus pancuronium). Data were collected during three periods: awake, postanesthetic induction, and posttracheal intubation. Four cardiovascular variables were designated a priori as primary variables of interest. These were heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), and systemic vascular resistance index (SVRI). Patients with mitral stenosis showed two significant hemodynamic differences among muscle relaxant drug groups: (1) CI increased in group A but decreased in group MP between the awake and postinduction measurements (P = 0.032); and (2) SVRI decreased in group A but increased in group MP between the awake and postintubation periods (P = 0.034). In contrast, patients with aortic stenosis, aortic regurgitation, or mitral regurgitation demonstrated no statistically significant difference in cardiovascular responses among drug groups. Further analysis was performed using the following data: (1) other hemodynamic variables; (2) incidence of deviations from cardiovascular stability; and (3) the frequency of cardiovascular drug use. This examination showed no important differences among the muscle relaxant drug groups. The small but significant hemodynamic changes observed in mitral stenosis patients in drug groups A and MP were not noted with vecuronium.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Anesthesia, Intravenous; Aortic Valve Insufficiency; Aortic Valve Stenosis; Atracurium; Blood Pressure; Cardiac Output; Double-Blind Method; Female; Heart Rate; Hemodynamics; Humans; Intubation, Intratracheal; Male; Middle Aged; Mitral Valve Insufficiency; Mitral Valve Stenosis; Neuromuscular Nondepolarizing Agents; Pancuronium; Prospective Studies; Time Factors; Tubocurarine; Vascular Resistance; Vecuronium Bromide

Physiological deadspace (VDphys) and arterial to end-tidal carbon dioxide tension difference [P(a-E)CO2] were calculated under anaesthesia in 27 patients with mitral stenosis planned for close mitral commissurotomy and in 15 healthy individuals for elective non-thoracic surgical procedures. A square wave inspiratory flow pattern and an end-inspiratory pause (25% and 10% of cycle time respectively) were given with a SERVO 900B ventilator used at respiratory rate of approximately 16 per min. An infra-red CO2 analyser was used to measure CO2 production and end-tidal CO2 concentration. Measurements were made prior to the start of the surgery after a minimum of 10 min of stable ventilation to avoid the effect of surgery. Patients with multiple stenosis had significantly higher VDphys (4.28 +/- 1.02 ml kg-1 as compared to 2.10 +/- 0.52 ml kg-1 in controls, P less than 0.001), higher P(a-E)CO2 [0.43 +/- 0.51 kPa as compared to -0.02 +/- 0.23 kPa, P less than 0.01] and lower respiratory system compliance (Crs). Péco2 was positively correlated with PaCO2 in both groups (P less than 0.01). PaO2 was lower in mitral stenosis patients and P(A-a)O2 negatively correlated to Crs (P less than 0.01).

Topics: Adult; Anesthesia, Intravenous; Carbon Dioxide; Female; Humans; Lung Compliance; Male; Mitral Valve Stenosis; Monitoring, Physiologic; Morphine; Oxygen; Pancuronium; Pulmonary Gas Exchange; Pulmonary Ventilation; Respiratory Dead Space; Thiopental; Tidal Volume

The hemodynamic effects of epidural anesthesia (EA) with the Trendelenburg position were studied in seven patients with severe mitral stenosis undergoing emergency cesarean section (CS) because of hemodynamic deterioration. In six patients, the CS was immediately followed by an open mitral commissurotomy under general anesthesia, whereas in one patient, the CS was performed alone. A significant reduction in heart rate (120 +/- 5 to 83 +/- 7 beats/min; P less than 0.001) was observed after induction of EA. Mean arterial pressure (MAP) decreased (78 +/- 9 to 55 +/- 5 mm Hg; P less than 0.01) simultaneously with reduction of the pulmonary capillary wedge pressure (PCWP) (37 +/- 4 to 15 +/- 4 mm Hg, P less than 0.001) and cardiac index (CI) (2.4 +/- 0.3 to 1.8 +/- 0.32 L/min/m2; P less than 0.001). However, PCWP could be adjusted by selecting the appropriate angle of the Trendelenburg position. When the PCWP was approximately 25 mm Hg, MAP and Cl increased to 72 +/- 7 mm Hg and 3.1 +/- 0.4 L/min/m2, respectively, and a satisfactory hemodynamic state was achieved. Systemic vascular resistance decreased after induction of EA (2,250 +/- 250 to 1,750 +/- 450 dyne.s.cm-5; P less than 0.001), and remained unchanged during the perioperative period. It is concluded that the combination of epidural anesthesia with tilting of the table is a safe method for urgent CS in pregnant women with critical mitral stenosis in whom termination of pregnancy is indicated because of hemodynamic deterioration.

Topics: Adult; Anesthesia, Epidural; Anesthesia, Intravenous; Anesthesia, Obstetrical; Blood Pressure; Bupivacaine; Cardiac Output; Cesarean Section; Female; Fentanyl; Flurazepam; Heart Rate; Hemodynamics; Humans; Mitral Valve Stenosis; Pancuronium; Posture; Pregnancy; Pregnancy Complications, Cardiovascular; Pulmonary Artery; Pulmonary Wedge Pressure; Rheumatic Heart Disease; Vascular Resistance