Anesthesiology
-
Randomized Controlled Trial Clinical Trial
Isoproterenol is an effective marker of intravenous injection in laboring women.
The purpose of this randomized, double-blind study was to determine if isoproterenol 5 micrograms iv produces a consistent, noticeable tachycardia in healthy, laboring women. Maternal heart rate, fetal heart rate, and uterine contractions were continuously recorded and maternal blood pressure was measured every minute for 10 min before and after each patient received either normal saline (NS group; n = 10) or isoproterenol 5 micrograms (ISO group; n = 10) iv. The data-collecting investigator and a nurse palpating the patient's radial artery determined which solution they thought had been administered. ⋯ Diastolic and mean blood pressures did not change. No fetal distress occurred. Isoproterenol 5 micrograms is an effective marker of intravascular injection in laboring women; however, the safety and efficacy of epidural isoproterenol must be demonstrated in animals before isoproterenol can be incorporated in an epidural anesthesia test dose.
-
Comparative Study
Correlation between bleeding times and platelet counts in women with preeclampsia undergoing cesarean section.
Platelet count and bleeding time and the correlation between these two variables in women with preeclampsia who received epidural or general anesthesia for cesarean section were evaluated. The study included 106 women with preeclampsia who were undergoing cesarean section and 94 healthy, term parturients receiving epidural anesthesia for labor analgesia or for cesarean section. Platelet counts were measured using an automated Coulter Counter, and bleeding times were measured using the modified Ivy bleeding time technique. ⋯ In addition, 34% of those women with severe preeclampsia and 13% with mild preeclampsia had prolonged bleeding time, although their platelet count was adequate. In the control group, 2% had abnormal bleeding time in the presence of a normal platelet count. There was good correlation between bleeding time and platelet count only when platelet count was lower than 100,000/mm3 (r = -0.76, P less than -0.02).
-
Randomized Controlled Trial Clinical Trial
Dose-response relationships for edrophonium and neostigmine as antagonists of atracurium and vecuronium neuromuscular blockade.
To determine the potencies of edrophonium and neostigmine as antagonists of nondepolarizing neuromuscular blockade produced by atracurium and vecuronium, dose-response curves were constructed for both antagonists when given at 10% spontaneous recovery of first twitch height. Ninety ASA physical status 1 and 2 adults were given either 0.4 mg/kg atracurium or 0.08 mg/kg vecuronium during thiopental-nitrous oxide-enflurane anesthesia. Train-of-four stimulation was applied to the ulnar nerve every 12 s, and the force of contraction of the adductor pollicis muscle was recorded. ⋯ The edrophonium ED80 was 0.44 +/- 0.11 mg/kg with atracurium and 0.46 +/- 0.12 mg/kg with vecuronium, giving a neostigmine:edrophonium potency ratio of 20. Atracurium train-of-four fade could be antagonized more easily with edrophonium, whereas that of vecuronium was more easily antagonized by neostigmine. It is concluded that edrophonium and neostigmine are not equally effective against atracurium and vecuronium.
-
Comparative Study
Prognostic importance of postbypass regional wall-motion abnormalities in patients undergoing coronary artery bypass graft surgery. SPI Research Group.
Regional wall motion abnormalities (RWMA) detected by intraoperative transesophageal echocardiography (TEE) are thought to be sensitive markers of myocardial ischemia. To assess the prognostic significance of RWMA as compared with other less costly technologies such as electrocardiography (ECG) and hemodynamic measurements [blood pressure (BP) and pulmonary artery (PA) pressure], 50 patients were prospectively studied who were undergoing elective coronary artery bypass graft (CABG) surgery using continuous TEE, ECG (Holter), and hemodynamic measurements during the prebypass, postbypass, and early postoperative intensive care unit (ICU) periods (first 4 h). Echocardiographic and ECG evidence of ischemia was characterized during each of these three periods and related to adverse clinical outcomes (postoperative myocardial infarction, ventricular failure, and cardiac death). ⋯ In contrast, postbypass TEE ischemia was predictive of outcome: six of 18 patients with postbypass TEE ischemia had adverse outcomes versus 0 of 32 without TEE ischemia (P = 0.001). Seventy-three percent of the echocardiographic ischemic episodes occurred without acute change (+/- 20% of control) in heart rate, BP, or PA pressure. The authors conclude that: 1) prebypass myocardial ischemia was relatively uncommon, 2) the incidence of ECG and TEE ischemia was highest in the postbypass period, and 3) postbypass RWMA were related to adverse clinical outcome.