Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe endotracheal tube moves more often in obese patients undergoing laparoscopy compared with open abdominal surgery.
We compared the incidence of movements of the endotracheal tube (ETT) within the trachea in morbidly obese patients undergoing either laparoscopic or open gastroplasty. In a double-blinded, prospective, controlled study, 60 patients (body mass index, 35-60 kg/m(2)) were equally allocated to either laparoscopic LapBand gastroplasty (study group; Group 1) or open laparotomy gastroplasty (control; Group 2), both under standardized general anesthesia. Movements of the ETT were assessed with chest auscultation, peak inspiratory pressure, ETCO(2), SpO(2), and the Rapiscope at predetermined time points: after intubation (baseline values), 5 min before peritoneal inflation in Group 1 and 10 min postintubation in Group 2, at maximal abdominal inflation in Group 1 and 20 min into the procedure in Group 2, 5 min before and 5 min after changing the patient's position from neutral to 10 degrees head up and 10 degrees head down in Group 1 and 30 and 40 min into the procedure in Group 2, 2 min after abdominal deflation and table repositioning in Group 1 and at 50 min in Group 2, and just before extubation in both groups. Twenty-one events of ETT tip movement occurred in both groups. The tube moved in 15 (50%) study (laparoscopy) group patients compared with 6 (20%) controls (laparotomy; P < 0.05), 12 of the former having moved downward either after maximal abdominal insufflation or in association with head-down positioning. The tubes of five study group patients (17%) advanced into the right bronchus, compared with none in the controls (P < 0.05). All changes in position were rectified only by the Rapiscope. ⋯ Abdominal insufflation and changes in table position lead to more frequent movements of the endotracheal tube in obese patients undergoing laparoscopic versus open gastroplasty. The Rapiscope identifies all these changes, but not the clinically available variables.
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Anesthesia and analgesia · Jan 2003
Comparative StudyAgreements between the prothrombin times of blood treated In Vitro with heparinase during cardiopulmonary bypass (CPB) and blood sampled after CPB and systemic protamine.
The prothrombin time (PT) is useful for identifying coagulation factor deficits after cardiopulmonary bypass (CPB). However, long processing times and the need for fresh frozen plasma (FFP) to be thawed cause delays in factor replacement. We hypothesized that, by treating with heparinase, blood sampled toward the end of CPB can provide PT results that help to determine the requirement for FFP after CPB. Laboratory delays can be eliminated with point-of-care monitors. We studied 158 adults undergoing nonemergent cardiac surgery. Blood taken before separation from CPB was mixed with heparinase, and PT was measured in the laboratory with a HemoTec timer. Agreements between these results and laboratory measurements of blood taken after systemic protamine were compared by using Bland and Altman plots with the threshold of +/-1.0 s. We found that the laboratory PT measurements during CPB versus after CPB were compara-ble, but the limits of agreement exceeded these thresholds. Similarly, there was unsatisfactory agreement between the HemoTec and laboratory PT results measured before, during, and after CPB. For each PT measured during CPB, the corresponding confidence interval for the postprotamine PT was calculated. During CPB, a laboratory PT of < or =16 s or > or =18 s suggests a > or =83% or > or =93% probability of not requiring or potentially requiring, respectively, FFP after CPB. We conclude that the majority of PT measurements obtained from blood taken before weaning from CPB and treated in vitro with heparinase was associated with a high probability of whether or not FFP would be needed after CPB. ⋯ Coagulation dysfunction after cardiopulmonary bypass may contribute to bleeding. Obtaining coagulation tests and fresh frozen plasma requires time and delays treatment in patients who need fresh frozen plasma. We have devised a technique to provide early estimation of postbypass coagulation status.
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Anesthesia and analgesia · Jan 2003
Review Meta AnalysisNonsteroidal antiinflammatory drugs and the risk of operative site bleeding after tonsillectomy: a quantitative systematic review.
The use of nonsteroidal antiinflammatory drugs (NSAIDs) for analgesia after tonsillectomy is controversial because NSAIDS, through platelet inhibition, may increase the risk of perioperative bleeding. We systematically searched for randomized, controlled trials that reported on the incidence of perioperative bleeding attributable to the use of NSAIDs in patients undergoing tonsillectomy. As secondary outcome measures, we analyzed the quality of pain relief and the incidence of postoperative nausea and vomiting. Twenty-five studies with data from 970 patients receiving a NSAID and 883 receiving a non-NSAID treatment or a placebo were analyzed. Data were combined using a fixed-effect model. Of four bleeding end points (intraoperative blood loss, postoperative bleeding, hospital admission, and reoperation because of bleeding), only reoperation happened significantly more often with NSAIDs: Peto-odds ratio, 2.33 (95% confidence interval [CI], 1.12-4.83) and number-needed-to-treat, 60 (95% CI, 34-277). Compared with opioids, NSAIDs were equianalgesic, and the risk of emesis was significantly decreased (relative risk, 0.73; 95% CI, 0.63-0.85; numbers-needed-to-treat, 9; 95% CI, 5-19). ⋯ The evidence for nonsteroidal antiinflammatory drugs to increase the risk of bleeding after tonsillectomy is equivocal, and the risk-benefit ratio is not straightforward. There is some evidence for an increased likelihood of reoperation because of bleeding. The agenda must be one of further research rather than of clinical recommendations.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Multicenter Study Clinical TrialInterscalene brachial plexus anesthesia and analgesia for open shoulder surgery: a randomized, double-blinded comparison between levobupivacaine and ropivacaine.
We compared the onset time and quality of interscalene brachial plexus block produced with levobupivacaine and ropivacaine in 50 patients undergoing open shoulder surgery randomly allocated to receive 30 mL of 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25) injected through a 20-gauge catheter placed into the interscalene sheath using a 18-gauge insulated and stimulating Tuohy introducer. The block was also prolonged after surgery using a patient-controlled interscalene analgesia with 0.125% levobupivacaine or 0.2% ropivacaine, respectively (basal infusion rate, 6 mL/h; bolus, 2 mL; lockout period, 15 min; maximum boluses per hour, three). Three patients (two with levobupivacaine [8%] and one with ropivacaine [4%]) failed to achieve surgical block within 45 min after the injection and were excluded. The onset time of surgical block was 20 min (10-40 min) with levobupivacaine and 20 min (5-45 min) with ropivacaine (P = 0.53). Rescue intraoperative analgesia (0.1 mg of fentanyl IV) was required in eight patients in each group (34%) (P = 0.99). Forty-two patients completed the 24-h postoperative infusion (22 with levobupivacaine and 20 with ropivacaine). Postoperative analgesia was similarly effective in both groups. Total consumption of local anesthetic infused during the first 24 h was 147 mL (144-196 mL) with levobupivacaine and 162 mL (144-248 mL) with ropivacaine (P = 0.019), with a ratio between boluses received and requested of 0.8 (0.4-1.0) and 0.7 (0.4-1.0), respectively (P = 0.004). The degree of motor block of the operated limb was deeper with levobupivacaine than ropivacaine when starting postoperative analgesia; however, no further differences in degree of motor function were observed between the two groups. We conclude that 30 mL of levobupivacaine 0.5% induces an interscalene brachial plexus anesthesia of similar onset and intensity as the one produced by the same volume and concentration of ropivacaine. Postoperative interscalene analgesia with 0.125% levobupivacaine results in similar pain relief and recovery of motor function with less volume of local anesthetic than with 0.2% ropivacaine. ⋯ This prospective, randomized, double-blinded study demonstrates that 30 mL of 0.5% levobupivacaine produces an interscalene brachial plexus block of similar onset and quality as the one produced by the same volume of 0.5% ropivacaine. When prolonging the block after surgery, 0.125% levobupivacaine provides adequate pain relief and recovery of motor function after open shoulder surgery, with less volume infused during the first 24 h after surgery than 0.2% ropivacaine.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialTarget-controlled infusion for remifentanil in vascular patients improves hemodynamics and decreases remifentanil requirement.
Remifentanil is a potent ultra-short-acting opioid, which permits rapid emergence. However, remifentanil is expensive and may have detrimental effects on hemodynamics in case of overdose. Target-controlled infusion (TCI) permits adapting infusion to pharmacokinetic models. In this prospective randomized study, we compared intra- and postoperative hemodynamics, remifentanil requirement during anesthesia, and postoperative morphine requirement in patients scheduled for carotid surgery, and receiving either continuous IV weight-adjusted infusion of remifentanil (RIVA) or TCI for remifentanil (TCIR). Forty-six patients were enrolled in this study: all were anesthetized by using TCI for propofol. Twenty-three received RIVA (0.5 micro g. kg(-1) x min(-1)) for the induction of anesthesia and endotracheal intubation, with the infusion rate decreased to 0.25 micro g x kg(-1) x min(-1) after intubation, then adapted by step of 0.05 micro g x kg(-1) x min(-1) according to hemodynamics. Twenty-three patients received TCIR (Minto model, Rugloop), with an effect-site concentration at 4 ng/mL during induction, then adapted by step of 1 ng/mL according to hemodynamics. All patients received atracurium and a 50% mixture of N(2)O/O(2). Hemodynamic variables were recorded each minute. The number and duration of hemodynamic events were collected, and total doses of anesthetics (remifentanil and propofol) and vasoactive drugs were noted in both groups of patients. Data were analyzed by using unpaired t-tests. RIVA was significantly associated with more frequent episodes of intraoperative hypotension (16 versus 6, P < 0.001) and more frequent episodes of postoperative hypertension and/or tachycardia requiring more frequent administration of beta-adrenergic blockers (16 vs 10, P < 0.04) in comparison with TCIR. The need for morphine titration was not significantly different between groups. TCIR led to a significantly smaller requirement of remifentanil (700 +/- 290 versus 1390 +/- 555 micro g, P < 0.001) without difference in propofol requirement. This prospective randomized study demonstrated that, during carotid endarterectomy, in comparison with patients receiving remifentanil using continuous RIVA, TCI results in less hypotensive episodes during the induction of anesthesia, in fewer episodes of tachycardia and/or hypertension and a smaller beta-adrenergic blocker requirement during recovery, and a decrease in remifentanil requirement. Recommendations to prefer TCI for remifentanil administration during carotid endarterectomy may be justified. ⋯ Remifentanil for intraoperative analgesia in carotid artery surgery is associated with a better stability in perioperative hemodynamics when administered in target-controlled infusion compared with continuous weight-adjusted infusion. This may be related to a smaller requirement of this drug when using target-controlled infusion, as well as a smooth mode of administration.