Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2000
Safe and efficient emergency transvenous ventricular pacing via the right supraclavicular route.
Infraclavicular and internal jugular central venous access are techniques commonly used for temporary transvenous pacing. However, the procedure still has a considerable complication rate, with a high risk/benefit ratio because of insertion difficulties and pacemaker malfunction. To enlarge the spectrum of alternative access sites, we prospectively evaluated the right supraclavicular route to the subclavian/innominate vein for emergency ventricular pacing with a transvenous flow-directed pacemaker as a bedside procedure. For 19 mo, 17 consecutive patients with symptomatic bradycardia, cardiac arrest, or torsade de pointes requiring immediate bedside transvenous pacing were enrolled in the study. The success rate, insertional complications, pacemaker performance, and patients' outcomes were recorded. Supraclavicular venipuncture was successful in all patients, in 16 of 17 at the first attempt. Adequate ventricular pacing was achieved within 1 to 5 min (median, 2 min) after venipuncture and within 10 s to 4 min (median, 30 s) after lead insertion (
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Anesthesia and analgesia · Mar 2000
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of rabeprazole, lansoprazole, and ranitidine for improving preoperative gastric fluid property in adults undergoing elective surgery.
Acid aspiration syndrome at the induction of anesthesia is still a potentially life-threatening complication. Its severity is affected by both pH and volume of the gastric juice that is aspirated. We compared the effects of rabeprazole (a new proton pump inhibitor), lansoprazole, and ranitidine on gastric fluid properties in a prospective, randomized, double-blinded fashion in 180 adult patients undergoing elective surgery. Patients were divided into six groups (n = 30 in each) according to their premedication. Patients in each group received placebo-rabeprazole (PLA-RAB), rabeprazole-placebo (RAB-PLA), rabeprazole-rabeprazole (RAB-RAB), lansoprazole-lansoprazole (LAN-LAN), placebo-ranitidine (PLA-RAN), or placebo-placebo (PLA-PLA) for the first-second medication. Each dose of the study drug was 20 mg for rabeprazole, 30 mg for lansoprazole, and 150 mg for ranitidine. The first medication was given orally at 9:00 PM on the day before surgery and the second at 5:30 AM on the day of surgery. Each patient fasted overnight and took the drug with 20 mL of water. After tracheal intubation, gastric fluid was aspirated via an orogastric tube, and the volume and pH of the aspirate was measured. Preoperative gastric fluid acidity and volume were improved by the study drugs in the following order: PLA-RAN (pH 5.3, volume 0.10 mL/kg), RAB-RAB, LAN-LAN, PLA-RAB, and RAB-PLA (pH 3.8, volume 0.22 mL/kg). The proportion of patients at risk of acid aspiration syndrome according to the traditional criteria (pH < 2.5 and volume > 0.4 mL/kg) was minimized in Groups RAB-RAB and PLA-RAN (0%). We concluded that a single morning dose of ranitidine rather than two doses (bedtime and morning) of rabeprazole was the most effective premedicant to control gastric fluid properties and to minimize the risk of aspiration pneumonitis. ⋯ Acid aspiration syndrome at the induction of anesthesia is rare but still a potentially life-threatening complication. We compared rabeprazole, lansoprazole, and ranitidine for reduction of preoperative gastric fluid acidity and volume in elective surgery and found that a combination of bedtime and morning doses of rabeprazole, or a morning dose of ranitidine, similarly minimized the variables. In adult patients who are at risk of aspirating gastric contents, improvement of gastric fluid environment by rabeprazole can reasonably be anticipated to provide protection against pneumonitis should regurgitation and aspiration of gastric contents occur.
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Anesthesia and analgesia · Mar 2000
Spinal nerve function in five volunteers experiencing transient neurologic symptoms after lidocaine subarachnoid anesthesia.
The etiology of transient neurologic symptoms (TNS) after 5% lidocaine spinal anesthesia remains undetermined. Previous case reports have shown that patients acutely experiencing TNS have no abnormalities on neurologic examination or magnetic resonance imaging. The aim of our study was to determine whether volunteers with TNS would exhibit abnormalities in spinal nerve electrophysiology. Twelve volunteers with no history of back pain or neurologic disease underwent baseline electromyography (EMG), nerve conduction studies, and somatosensory-evoked potential (SSEP) testing. Then, the volunteers were administered 50 mg of 5% hyperbaric lidocaine spinal anesthesia and were placed in a low lithotomy position (legs on four pillows). The next day, all volunteers underwent follow-up EMG, nerve conduction, and SSEP testing and were questioned and examined for the presence of complications including TNS (defined as pain or dysthesia in one or both buttocks or legs occurring within 24 h of spinal anesthesia). Volunteers who had TNS underwent additional EMG testing 4-6 wk later. Five of the 12 volunteers reported TNS. No volunteer had an abnormal EMG, nerve conduction study, or SSEP at 24 h follow up, nor were there any changes in EMG studies at delayed testing in the five volunteers experiencing TNS. On statistical analysis, the right peroneal and the right tibial nerve differed significantly for all volunteers from pre- to postspinal testing. When comparing pre- and postspinal testing of the TNS and non-TNS volunteers, statistically significant changes occurred in the nerve conduction tests of the right peroneal and left tibial nerve. There was no difference in measurements of F response, H reflex latency, amplitude, or velocity for either leg. Multivariate analysis of variance showed no significant difference between TNS and non-TNS volunteers for the changes in the nine nerve conduction tests when considered together (P = 0.4). We conclude that acute TNS after lidocaine spinal anesthesia did not result in consistent abnormalities detectable by EMG, nerve conduction studies, or SSEP in five volunteers. ⋯ Electrophysiologic testing in volunteers experiencing transient neurologic symptoms is not abnormal.
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Anesthesia and analgesia · Mar 2000
Randomized Controlled Trial Comparative Study Clinical TrialThe efficacy of intravenous 0.15 versus 0.25 mg/kg intraoperative morphine for immediate postoperative analgesia after remifentanil-based anesthesia for major surgery.
We evaluated the effect of perioperative administration of two doses of morphine for postoperative analgesia after remifentanil-based anesthesia. The prospective, randomized study included 245 patients from 33 centers. All patients were scheduled for abdominal or urological surgery lasting more than 1 h. General anesthesia used remifentanil as the perioperative opioid (1 microg/kg as a bolus then, 0.5 microg/kg as a continuous infusion). A morphine bolus of 0. 15 mg/kg (0.15-mg group) or 0.25 mg/kg (0.25-mg group) was administered 30 min before the end of surgery. In the postanesthesia care unit, pain scores for patients were evaluated by using behavioral pain scores of 1-3, verbal pain scores of 0-3, and visual analog scale scores of 0-10). Postoperative analgesia was obtained by a morphine titration (3 mg every 5 min). Demographic and surgery characteristics were similar in both groups. The delay for first demand of morphine was similar in the 0.15-mg and the 0.25-mg groups (26 [9-60] and 30 [10-60] min, respectively). The frequency of morphine titration was similar in both groups (75% and 66%, respectively). The amount of morphine used in the postanesthesia care unit was smaller in the 0.25-mg group (0.16 [0.0-1.25] vs 0.10 [0.0-0.56] mg/kg; P = 0.008). In the 0.25-mg group, the behavioral pain score was lower at 15 min, the verbal pain score was lower at 60 min (P < 0.001), and similar at 30 min. The visual analog scale pain score at 30 min and 60 min was similar in both groups. The incidence of minor side effects was similar in both groups. However, three cases of postoperative respiratory depression occurred in the 0.25-mg group compared with no cases in the 0.15-mg group. In conclusion, perioperative administration of morphine alone does not provide entirely adequate immediate postoperative pain control after remifentanil-based anesthesia in major surgery. ⋯ The administration of 0.15 or 0.25 mg/kg perioperative morphine during remifentanil-based anesthesia for major surgery does not preclude additional morphine administration in the postanesthesia care unit. The larger dose of 0.25 mg/kg slightly improves postoperative analgesia; however, it may be responsible for postoperative respiratory depression.
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Anesthesia and analgesia · Mar 2000
Randomized Controlled Trial Comparative Study Clinical TrialThe incidence of right upper-lobe collapse when comparing a right-sided double-lumen tube versus a modified left double-lumen tube for left-sided thoracic surgery.
Lung deflation for left-sided thoracic surgery can be accomplished by using either a left- or right-sided double-lumen endotracheal tube (L-DLT or R-DLT). Anatomic variability of the right mainstem bronchus and the possibility of right upper-lobe obstruction have discouraged the routine use of R-DLT. There are, however, situations in which it is preferable to avoid manipulation/intubation of the left main bronchus, requiring placement of a R-DLT. We compared the modified L-DLT with the R-DLT to determine whether R-DLTs can be used during left-sided thoracic surgery without an increased risk of right upper-lobe collapse. Forty patients requiring left lung deflation were randomly assigned to one of two groups. Twenty patients received a modified L-DLT BronchoCath((R)) (Mallinckrodt Medical Inc., St. Louis, MO), and 20 received a R-DLT BronchoCath((R)). The following variables were studied: 1) time required to position each tube until satisfactory placement was achieved; 2) number of times fiberoptic bronchoscopy was required to readjust tube position; 3) number of malpositions after initial tube placement; 4) time required for left lung collapse; 5) incidence of right upper-lobe collapse from an intraoperative chest radiograph obtained in a lateral decubitus position; 6) overall surgical exposure; and 7) tube acquisition cost. Median time required for initial tube placement was greater in the R-DLT group (3.4 min) versus the L-DLT (2.1 min); P = 0.04. Overall tube cost was also larger for the R-DLT group (US $1819.40) versus the L-DLT group (US $1107.75). The incidence of malpositions, (five versus two), need for fiberoptic bronchoscopy, time for adequacy of left lung collapse, and incidence of intraoperative right upper-lobe collapse (0) did not significantly differ between R-DLT and L-DLT groups. We conclude that R-DLTs can be used for left-sided thoracic surgery without an increased risk of right upper-lobe collapse. Our data suggest that R-DLTs may be more prone to intraoperative dislodgment/malposition than L-DLTs; however, in all cases, correction of malposition was easily achieved. ⋯ In this study, right-sided double-lumen tubes (R-DLTs) were compared with modified left-sided double-lumen tubes in patients requiring one-lung ventilation for left-sided thoracic surgery. The incidence of right upper-lobe collapse was assessed intraoperatively by a chest radiograph which showed no collapse of the right upper lobe in all patients who received R-DLTs or left-sided double-lumen tubes. Therefore, we conclude that R-DLTs present no increased risk of complications for left-sided thoracic surgery and should not be abandoned.