Anesthesia and analgesia
-
Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Clinical TrialOptimal dose of granisetron for prophylaxis against postoperative emesis after gynecological surgery.
We previously reported that 20 and 40 microg/kg of granisetron given during anesthesia prevented postoperative emesis with no severe complications. The aim of the current study was to determine the optimal dose of granisetron for the prevention of postoperative nausea and vomiting (PONV) after gynecological surgery. Two hundred female patients (ASA physical status I) were randomly allocated to one of five groups (n = 40 for each): saline (as a control), granisetron 2 microg/kg, granisetron 5 microg/kg, granisetron 10 microg/kg, and granisetron 20 microg/kg. Saline or granisetron was given intravenously immediately after induction of anesthesia. PONV was assessed 24 h after surgery. The percentage of emesis-free patients was significantly greater in the 5- to 20-microg/kg granisetron groups than in the control and 2-microg/kg granisetron groups (18%, 23%, 68%, 78%, and 75% of patients receiving saline or granisetron 2 microg/kg, 5 microg/kg, 10 microg/kg, and 20 microg/kg, respectively). Granisetron doses of 5 microg/kg or larger were also superior to the saline and 2-microg/kg granisetron treatment for the prevention of nausea over the 24-h study period (nausea visual analog scales 24 h after surgery: 49, 41, 18, 16, and 14 mm in the control and granisetron 2 microg/kg, 5 microg/kg, 10 microg/kg, and 20 microg/kg groups, respectively). A smaller proportion of patients received "rescue" antiemetic in the 5-microg/kg or larger granisetron groups than in the control and 2-microg/kg granisetron groups (48%, 40%, 18%, 13%, and 10% of patients in the control and granisetron 2 microg/kg, 5 microg/kg, 10 microg/kg, and 20 microg/kg groups, respectively). The antiemetic effect of granisetron was similar among the groups who received 5-microg/kg or larger doses. In conclusion, we suggest that the optimal dose of granisetron is 5 microg/kg for the prevention of PONV after gynecological surgery. ⋯ Nausea and vomiting postoperatively after gynecologic surgery is a significant problem. The authors found that granisetron, a selective antagonist of serotonin, markedly decreases the incidence of postoperative nausea and vomiting at doses of 5 microg/kg or larger.
-
Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Comparative Study Clinical TrialThe laryngeal mask airway: a comparison between two insertion techniques.
The purpose of the study was to compare the ease of insertion of the laryngeal mask airway using the standard uninflated approach or with a fully inflated cuff. Two hundred consecutive patients undergoing anesthesia using a laryngeal mask airway were randomized to have the laryngeal mask inserted using either method. Successful insertion was judged primarily by the clinical function of the airway. The number of insertion attempts to achieve a satisfactory airway and whether an alternative technique was required for success were recorded. On removal of the laryngeal mask, a blind observer noted the presence or absence of blood. Just before leaving the recovery room, each patient was asked whether they had a sore throat. Insertion technique made no difference with regard to first attempt success. However, the presence of blood on the removed masks (P < 0.01) and sore throat (P < 0.01) were less frequent in the inflated cuff group. We conclude that the inflated cuff insertion technique is an acceptable alternative to the standard approach and has the advantage of reducing the incidence of minor pharyngeal mucosal trauma, as evidenced by mucosal bleeding and sore throat. ⋯ Insertion of the laryngeal mask airway with the cuff fully inflated is equally successful to the standard uninflated approach in experienced hands. The inflated technique was associated with less minor pharyngeal mucosal trauma and, consequently, a lower incidence of postoperative sore throat. This implies that the inflated technique would be acceptable to the general population of laryngeal mask users.
-
Anesthesia and analgesia · Sep 1997
Comparative StudyDose-response and time course of effect of rocuronium in male and female anesthetized patients.
To determine differences from dose-response and time-course of rocuronium between male and female patients, 60 adult patients (30 male and 30 female), ASA grade I, aged 17-52 yr, undergoing elective plastic surgery were studied. Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 s, and the percentage depression of the T1 response was used as the study variable. The dose-response relationship of rocuronium was determined by a cumulative dose-response technique. The results showed that the dose-response curve of rocuronium in the men was shifted to the right, indicating a decrease in the sensitivity to rocuronium-induced neuromuscular block versus the women. The 50%, 90%, and 95% effective doses of rocuronium were 178.4 +/- 53.7, 358.7 +/- 101.3, and 386.2 +/- 113.4 microg/kg, respectively, in male patients, and 128.8 +/- 42.5, 252.8 +/- 51.7, and 274.4 +/- 59.4 microg/kg in female patients. After an intravenous administration of total dose of 400 microg/kg rocuronium, neuromuscular block was significantly longer in the men than in the women. The duration of peak effect, clinical duration, and total duration were 6.5 +/- 3.0, 12.5 +/- 4.9, and 33.6 +/- 8.7 min, respectively, in male patients, and 11.8 +/- 2.7, 18.5 +/- 5.3, and 46.8 +/- 9.6 min in female patients. We conclude that women were approximately 30% more sensitive to rocuronium compared with men. ⋯ The authors found that women were 30% more sensitive to rocuronium than men. This suggests that the routine dose of rocuronium should be reduced in women compared with men.
-
Anesthesia and analgesia · Sep 1997
Comparative StudyContinuous cardiac output monitoring during adult liver transplantation: thermal filament technique versus bolus thermodilution.
Continuous thermodilution (CT) using a pulmonary artery (PA) catheter with a thermal filament has the potential for intraoperative on-line monitoring of cardiac output. Liver transplantation frequently requires rapid fluid administration and often includes the use of an extracorporeal veno-venous bypass. To assess the agreement between CT and bolus thermodilution (BT) in such a setting, we conducted a prospective intraoperative study in 14 liver transplant patients. Throughout the operation, CT cardiac output was recorded and paired with BT measurements taken every 30 min and whenever indicated for clinical reason. Corresponding data were assigned to acquisition periods when patients were on or off veno-venous bypass (flow rate 2.5 +/- 0.2 L/min) and were discriminated by the various range of intravenous infusion rates (< 150 mL/h, 150-1000 mL/h, 1000-2000 mL/h, and 2000-4000 mL/h) and the magnitude of cardiac output (< or = 7.5 L/min, 7.5-10.0 L/min, > 10.0 L/min). A total of 270 data pairs was obtained and examined by analysis of agreement (mean difference +/- SD), variance, error, and weighted regression. Trend analysis was performed for significant CT and BT cardiac output changes, defined as changes greater than 15%. Agreement of both methods was best at peripheral intravenous fluid infusion rates < or = 1000 mL/h and BT cardiac output > 10 L/min (0.0 +/- 0.6 L/min) and was unaffected by veno-venous bypass. Discrepancy was most evident at intravenous fluid infusion rates > 2000 mL/h and BT cardiac output < or = 7.5 L/min (2.1 +/- 1.7 L/min). Correlation of CT and BT cardiac output was excellent (r = 0.95, P < 0.001) for combined data from all patients. Changes in CT cardiac output > 15% (n = 116) correctly indicated the direction in 93% of BT cardiac output changes and were 74% sensitive and 75% specific for significant BT cardiac output changes. The thermal filament technique enhances the usefulness of PA catheterization during liver transplantation but reflects BT cardiac output with clinically acceptable error only at low peripheral intravenous fluid infusion rates. ⋯ Cardiac output determines organ perfusion. In clinical practice, it is measured by intermittent thermodilution using right heart catheterization. This intraoperative study compared the intermittent method with a technique based on continuous thermodilution. The new technique provides logistical advantages and challenges the accuracy of the intermittent method during liver transplantation.
-
Anesthesia and analgesia · Sep 1997
Comparative StudyThe effect of priming with vecuronium and rocuronium on young and elderly patients.
The priming principle consists of administering a subparalyzing dose of nondepolarizing neuromuscular blocking drug 3-6 min before giving a second dose for tracheal intubation. This study was performed to observe the effects of priming doses of vecuronium and rocuronium on pulmonary function tests and muscular weaknesses in young (25-35 yr of age) and elderly (65-73 yr of age) patients. Ten young and 10 elderly patients were each placed in vecuronium and rocuronium groups. Oxygen saturation and train-of-four (TOF) ratio were determined, and pulmonary function tests were performed. Then 20% of the 95% effective dose (ED95) of the muscle relaxants was given intravenously. All tests were performed again 4 min after vecuronium and 3 min after rocuronium. Other signs of muscular weaknesses were also recorded. Elderly patients showed more signs of muscle weakness in both groups. The TOF ratio was 0.77 and 0.79 in the elderly rocuronium and vecuronium groups, respectively, and 0.89 and 0.90 in the young rocuronium and vecuronium groups, respectively. Dynamic spirometry revealed decreases in forced expiratory volume in 1 s and forced vital capacity in both groups, and no significant changes in peak expiratory flow rate. The expiratory reserve volume was reduced more in the elderly groups. Oxygen saturation decreased in both groups. We conclude that oxygen saturation, pulmonary function, and muscle strength decrease more in the elderly than in their younger counterparts from priming doses of vecuronium or rocuronium. ⋯ The priming principle consists of giving a subparalyzing dose of muscle relaxant 3-6 min before giving a second dose for tracheal intubation. We found that priming doses of vecuronium and rocuronium produced greater decreases in oxygen saturation and pulmonary function in the elderly (aged 65-73 yr) than their younger (aged 25-35 yr) counterparts. Priming may not be a safe approach in elderly patients.