Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Clinical TrialTranexamic acid is effective in decreasing postoperative bleeding and transfusions in primary coronary artery bypass operations: a double-blind, randomized, placebo-controlled trial.
We evaluated the effects of tranexamic acid (TA) administered before and after cardiopulmonary bypass (CPB) in a prospective, randomized, placebo-controlled, double-blind study of adult patients undergoing primary coronary artery bypass grafting surgery. Patients received placebo (n = 30) or TA 15 mg/kg before CPB, followed by a TA infusion of 1 mg x kg(-1) x h(-1) for 5 h (n = 30) or TA 15 mg/kg after CPB, followed by a TA infusion of 1 mg x kg(-1) x h(-1) for 5 h (n = 30). Demographic, medical, surgical, laboratory, mediastinal chest tube drainage (MCTD), hemoglobin loss, transfusion, and outcome data were collected. Allogenic blood product administration was tightly controlled. The demographic, medical, and surgical characteristics were similar in all three groups. The median postoperative MCTD and hemoglobin loss in the pre-CPB TA group (710 mL, 8.6 g) was significantly less (P < 0.001) compared with the control (1202 mL, 44.2 g) and post-CPB TA groups (1020 mL, 23.4 g). The percentage of patients who received no allogenic blood products was 27% for the pre-CPB TA group and 33% for the post-CPB TA group (not significant). These percentages were significantly lower than those in the placebo group (66%, P < 0.001). The median number of allogenic blood products administered to the pre-CPB TA group (0 units) was significantly less compared with the control group (4.5 units). The thromboelastogram and fibrinogen split product levels in the pre-CPB TA group indicated better platelet function and less activation of the fibrinolytic system compared with the other two groups (P < 0.05). There were no intergroup differences in reoperation, myocardial infarction, stroke, infections, or death. These data support the use of pre-CPB TA to decrease patient exposure to postcardiopulmonary bypass allogenic blood products. ⋯ In this randomized, placebo-controlled trial, we investigated the efficacy of tranexamic acid to decrease bleeding and blood transfusions after open-heart operations. Tranexamic acid administered before and during the operation was effective in decreasing both bleeding and transfusions. When tranexamic acid was administered immediately after the operation, it had a minor beneficial effect.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Comparative Study Clinical TrialA comparative efficacy study of hyperbaric 5% lidocaine and 1.5% lidocaine for spinal anesthesia.
We compared the clinical efficacy of 1.5% lidocaine in dextrose 7.5% in water, which is currently available as a commercial preparation but approved for use only in obstetrical patients, with the traditional 5% lidocaine in dextrose 7.5% in water for spinal anesthesia in patients undergoing lower abdominal procedures. Fifty-one male patients scheduled to undergo inguinal herniorrhaphy were randomly divided into two groups based on the spinal anesthetic received: Group I received 1.5% lidocaine in dextrose 7.5% in water, and Group II received 5% lidocaine in dextrose 7.5% in water. After intrathecal injection of the anesthetic, each patient was evaluated for the speed of onset, the time to recovery, and the quality of the surgical anesthesia and motor block that ensued by an anesthesiologist blinded to the technique. With the exception of the patients in Group I, who achieved a higher dermatome level of sensory analgesia, we were unable to demonstrate any significant clinical differences between the two lidocaine solutions. Our results indicate that lidocaine 1.5% in dextrose 7.5% in water is clinically indistinguishable from the 5% solution as a spinal anesthetic for lower abdominal surgery. ⋯ In this study, two concentrations of lidocaine are compared as spinal anesthetics in 51 male patients undergoing inguinal hernia repair. Patients were assessed for the onset, quality, and duration of the spinal block. The study results indicate that 1.5% lidocaine is as effective as the 5% solution as a spinal anesthetic for patients undergoing inguinal hernia repair.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Clinical TrialMyocardial ischemia and adverse cardiac outcomes in cardiac patients undergoing noncardiac surgery with sevoflurane and isoflurane. Sevoflurane Ischemia Study Group.
Sevoflurane is associated with less tachycardia and coronary vasodilation than isoflurane and thus might be associated with less myocardial ischemia. This multicenter study examined the incidence of myocardial ischemia and adverse cardiac outcomes in adults (40-87 yr) with cardiac disease having elective noncardiac surgery. Patients were randomized to receive either sevoflurane (S) (n = 106) or isoflurane (I) (n = 108) in conjunction with sodium thiopental, vecuronium, fentanyl, and 50%-70% N2O. Intraoperative hemodynamics were maintained within 20% of awake baseline with standard drugs. A Holter monitor was applied 3-24 h before surgery and maintained until 48 h after surgery. Electrocardiograms and blood samples for analysis of the MB isoenzyme fraction of creatine phosphokinase were obtained preoperatively and daily for 48 h postoperatively. Anesthetic exposure (1.79 +/- 0.15 [mean +/- SE] minimum alveolar concentration-hour) and duration of surgery (219 +/- 13 min) did not differ between groups. The incidence of ischemia in the pre-, intra- and postoperative periods, adverse cardiac outcomes (18% occurrence), intraoperative hemodynamic variations (+/-20% change from ward baseline), and administration of adjunct cardiovascular medications were similar between groups. In cardiac patients having noncardiac surgery, sevoflurane was comparable to isoflurane with respect to the incidence of intra- and postoperative myocardial ischemia and in the frequency of adverse cardiac outcomes. ⋯ Surgical patients with heart disease are at risk of heart complications, some of which could be induced by an anesthetic. We compared the incidence of cardiac complications between patients receiving sevoflurane and isoflurane. We found that the frequency of additional heart problems in cardiac patients receiving sevoflurane was not different from that associated with isoflurane.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Clinical TrialTeaching the use of fiberoptic intubation for children older than two years of age.
In 144 anesthetized children aged 2-9 yrs, the safety and feasibility of orotracheal fiberoptic intubation, with and without an airway endoscopy mask, were assessed and compared with laryngoscopic intubation. Eight anesthesia residents with experience in adult fiberoptic intubation, but who were beginners in pediatric anesthesia, participated in this study. In a randomized fashion, each resident intubated 18 children (6 in each group). The time (mean +/- SD) to achieve successful intubation was different for laryngoscopic and fiberoptic intubation (34 +/- 17 s and 80 +/- 39 s, respectively; P < 0.001). The use of the airway endoscopy mask further prolonged fiberoptic intubation (167 +/- 121 s, P < 0.001). Spo2 values remained >95% in all patients during conventional laryngoscopy and fiberoptic laryngoscopy with a mask, whereas Spo2 decreased below 95% in 2 of the 48 patients during fiberoptic intubation without a mask. Both patients promptly recovered during ventilation via a face mask. We conclude that teaching the use of fiberoptic intubation in healthy, anesthetized children aged 2-9 yrs is safe and feasible. ⋯ Fiberoptic intubation is a valuable technique of airway management. We studied the feasibility and safety of a training program that could be used for children more than 2 yrs old. This study demonstrates that fiberoptic intubation can be effectively practiced in pediatric patients without increased risk of side effects.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Clinical TrialNitrous oxide enhances the level of sensory block produced by intrathecal lidocaine.
We examined the effect of nitrous oxide (N2O) administration on the level of sensory block produced by intrathecal lidocaine in patients undergoing transurethral procedures. Twenty minutes after subarachnoid injection of 100 mg (5%) hyperbaric lidocaine, the level of block to pressure sensation was assessed. After establishing the baseline sensory block, patients were randomly assigned to receive either 50% nitrogen (control group) or 50% N2O in oxygen for 10 min, and the sensory level was reassessed. All patients then received 35% oxygen for 5 min, and the level of block to pressure was assessed again. Changes were measured in centimeters and standardized by dividing those results by the height of patients (in centimeters). Ten minutes after nitrogen or N2O administration, a 3.8-cm regression of sensory block was found in the control group, and a 1.8-cm cephalad increase was found in the treatment group (P < 0.0001). Discontinuation of N2O for 5 min resulted in a rapid regression of the level of sensory block (4 cm in the N2O group versus 1.9 cm in the control group, P < 0.0001). However, 5 min after discontinuation of N2O, the overall regression of the sensory block in the control group, when measured from the baseline, was 5.7 cm versus 2.2 cm in the N2O group (P < 0.001). The differences between the two groups before standardization are consistent with those after standardization (t = 9.02 at 10 min, t = 4.24 at 15 min, and t = 3.97 for the overall change at 15 min). The results suggest that inhalation of 50% N2O enhances the level of sensory block produced by intrathecal lidocaine. ⋯ We measured the level of sensory block produced by subarachnoid anesthesia with lidocaine before and after inhalation of 50% nitrous oxide for 10 min. Nitrous oxide enhanced the level of subarachnoid anesthesia with minimal hemodynamic effects. These findings are of clinical importance when subarachnoid anesthesia subsides before the completion of surgery.