ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundBoard certification is often used as a surrogate indicator of provider competence, although few outcome studies have demonstrated its validity. The aim of this study was to compare the outcomes of patients who underwent surgical procedures under the care of an anesthesiologist with or without board certification.MethodsMedicare claims records for 144,883 patients in Pennsylvania who underwent general surgical or orthopedic procedures between 1991 and 1994 were used to determine provider-specific outcome rates adjusted to account for patient severity and case mix, and hospital characteristics. Outcomes of 8,894 cases involving midcareer anesthesiologists, 11–25 yr from medical school graduation, who lacked board certification were compared with all other cases. Midcareer anesthesiologist cases were studied because this group had sufficient time to become certified during an era when obtaining certification was already considered important, and consequently had the highest rate of board certification. Mortality within 30 days of admission and the failure-to-rescue rate (defined as the rate of death after an in-hospital complication) were the two primary outcome measures.ResultsAdjusted odds ratios for death and failure to rescue were greater when care was delivered by noncertified midcareer anesthesiologists (death = 1.13 [95% confidence interval, 1.00, 1.26],P< 0.04; failure to rescue = 1.13 [95% confidence interval, 1.01, 1.27],P< 0.04). Adjusting for international medical school graduates did not change these results.ConclusionsWhen anesthesiology board certification is very common, as in midcareer practitioners, the lack of board certification is associated with worse outcomes. However, the poor outcomes associated with noncertified providers may be a result of the hospitals at which they practice and not necessarily their manner of practice.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundThere are few repeated dose-controlled trials ofN-methyl-d-aspartate glutamate receptor antagonists in patients with neuropathic pain. The authors sought to evaluate two low-affinityN-methyl-d-aspartate antagonists using a novel two-stage design.MethodsThe authors studied patients with painful diabetic neuropathy (DN) and postherpetic neuralgia (PHN) in two crossover trials: (1) efficacy trial (dextromethorphanvs.memantinevs.active placebo [lorazepam]) and (2) dose–response trial of the preferred active drug in responders from the first study (0%vs.25%vs.50%vs.100% of each patient's maximally tolerated dose). Pain intensity was measured on a 20-point scale.ResultsNineteen of 23 DN patients and 17 of 21 PHN patients completed the efficacy trial. Median doses for DN and PHN were 400 and 400 mg/day dextromethorphan, 55 and 35 mg/day memantine, and 1.8 and 1.2 mg/day lorazepam. In the efficacy trial, among patients with DN, dextromethorphan reduced pain intensity by a mean of 33% from baseline, memantine reduced pain intensity by a mean of 17%, and lorazepam reduced pain intensity by a mean of 16%; the proportions of subjects achieving greater than moderate pain relief were 68% with dextromethorphan, 47% with memantine, and 37% with lorazepam. Mean reductions in pain intensity in patients with PHN were 6% with dextromethorphan, 2% with memantine, and 0% with lorazepam. No comparison with placebo reached statistical significance in the efficacy trial. In the 10 DN subjects who responded to dextromethorphan, there was a significant dose–response effect on pain intensity (P= 0.035), with the highest dose significantly better than that of lorazepam (P= 0.03).ConclusionsDextromethorphan is effective in a dose-related fashion in selected patients with DN. This was not true of PHN, suggesting a difference in pain mechanisms. Selective approaches to pain-relevantN-methyl-d-aspartate receptors are warranted.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundChanging plasma protein concentrations may affect the protein binding and pharmacokinetics of drugs in the postoperative period. This study examined the effect of postoperative increases (in response to surgery) in plasma &agr;1-acid-glycoprotein (AAG) concentrations on the plasma concentrations of the enantiomers of bupivacaine during continuous epidural infusion of racemic bupivacaine for postoperative pain relief.MethodsSix patients scheduled for total hip surgery with combined epidural and general anesthesia received a bolus dose of bupivacaine (65 mg) followed by constant-rate (8 ml/h) epidural infusion of 2.5 mg/ml bupivacaine for 48 h. Total and unbound plasma concentrations of the enantiomers of bupivacaine and plasma AAG concentrations during the 48-h epidural infusion were determined.ResultsTotal plasma concentrations of the enantiomers of bupivacaine increased steadily during the infusion (P< 0.0001), whereas unbound concentrations did not change after 12 h (P> 0.1). Total plasma concentrations ofS(−)-bupivacaine were higher than those ofR(+)-bupivacaine (P< 0.02), whereas unbound concentrations ofS(−)-bupivacaine were lower than those ofR(+)-bupivacaine (P< 0.002). AAG concentrations initially decreased, but thereafter increased steadily (P< 0.0001). Consequently, free fractions of the enantiomers initially increased and then decreased with time (P= 0.0002). Free fractions ofS(−)-bupivacaine were smaller than those ofR(+)-bupivacaine (P= 0.0003).ConclusionsThe study confirmed that the pharmacokinetics of bupivacaine are enantioselective. During postoperative epidural infusion, changing plasma AAG concentrations affect the protein binding of both enantiomers of bupivacaine. Consequently, total plasma concentrations of the enantiomers increase with time, whereas unbound concentrations reach a plateau.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundThe use of intrathecal opioids for labor analgesia continues to gain popularity, but there are limited data to guide this use. Previously, the authors established the ED50for 60 min of labor analgesia from intrathecal sufentanil using an up–down sequential allocation study design. The current study first establishes an ED50for intrathecal fentanyl using this same study design to establish an intrathecal potency ratio for fentanyl and sufentanil and then uses this ratio to compare the efficacy, duration of analgesia, and side effects from comparable doses of intrathecal fentanyl and sufentanil.MethodsSeventy-five healthy nulliparous women requesting labor analgesia were enrolled in this two-part study. In phase I, 20 women received varying doses of fentanyl to establish an ED50for 60 min of labor analgesia. In phase II, 55 women were randomized to receive either 36 &mgr;g intrathecal fentanyl or 8 &mgr;g sufentanil (2 times the ED50s)viaa combined spinal–epidural technique and by double-blinded design. Pain relief, side effects, block height, maternal hemodynamics, and fetal heart rate were assessed throughout the study. The duration of spinal analgesia was considered to be the time from injection of study drug to the time of the patient's first request for additional analgesia.ResultsThe ED50of intrathecal fentanyl for 60 min of labor analgesia was found to be 18.2 &mgr;g, and therefore, the potency ratio of intrathecal sufentanil to intrathecal fentanyl at the ED50level is 4.4:1. The duration of spinal analgesia was significantly longer from 8 &mgr;g intrathecal sufentanil than from 36 &mgr;g intrathecal fentanyl (104 ± 34vs.79 ± 34 min,P= 0.009). Otherwise, patient demographics, maternal hemodynamics, duration of labor, mode of delivery, motor block, subjective leg weakness, pruritus, nausea, pinprick sensory levels, visual analog scale pain scores, fetal bradycardia, and Apgar scores were similar between groups.ConclusionThe relative potency of intrathecal sufentanil to fentanyl for labor analgesia is 4.4:1. When using intrathecal opioids alone for early labor analgesia, 8 &mgr;g sufentanil produces labor analgesia lasting approximately 25 min longer than from 36 &mgr;g fentanyl, without a statistically significant increase in side effects. However, when making a choice between fentanyl and sufentanil, one must consider other important factors, such as the higher cost of sufentanil and the greater risk of dosing error due to the higher potency of sufentanil compared with fentanyl.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundThe authors determined the influence of cuff volume and anatomic location on pharyngeal, esophageal, and tracheal mucosal pressures for the esophageal tracheal combitube.MethodsTwenty fresh cadavers were studied. Microchip sensors were attached to the anterior, lateral, and posterior surfaces of the distal and proximal cuffs of the small adult esophageal tracheal combitube. Mucosal pressure for the proximal cuff in the pharynx was measured at 0- to 100-ml cuff volume in 10-ml increments, and for the distal cuff in the esophagus and trachea were measured at 0- to 20-ml cuff volume in 2-ml increments. The proximal cuff volume to form an oropharyngeal seal of 30 cm H2O was determined. In addition, mucosal pressures for the proximal cuff in the pharynx were measured in four awake volunteers with topical anesthesia.ResultsThere was an increase in mucosal pressure in the trachea, esophagus, and pharynx at all cuff locations with increasing volume (all:P< 0.001). Pharyngeal mucosal pressures were highest posteriorly (50-ml cuff volume: 99 ± 62 cm H2O; 100-ml cuff volume: 255 ± 161 cm H2O). Esophageal mucosal pressures were highest posteriorly (10-ml cuff volume: 108 ± 55 cm H2O; 20-ml cuff volume: 269 ± 133 cm H2O). Tracheal mucosal pressures were highest anteriorly (10-ml cuff volume: 98 ± 53 cm H2O; 20-ml cuff volume: 236 ± 139 cm H2O). The proximal cuff volume to obtain an oropharyngeal seal of 30 cm H2O was 47 ± 12 ml. Pharyngeal mucosal pressures were similar for cadavers and awake volunteers.ConclusionWe conclude that mucosal pressures for the esophageal tracheal combitube increase with cuff volume, are highest where the cuff is adjacent to rigid anatomic structures, and potentially exceed mucosal perfusion pressure even when cuff volumes are limited to achieving an oropharyngeal seal of 30 cm H2O.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundIncreased neutrophil activation by cardiopulmonary bypass (CPB) during cardiovascular surgery is thought to be responsible for postoperative complications. In children, the contribution of cardiovascular surgery alone to this response is not well-characterized.MethodsChildren undergoing surgery with CPB (CPB group, n = 35) and without CPB (control, n = 22) were studied (age, 3–17 yr). Blood was drawn 24 h preoperatively before medication, after anesthesia, after connection to CPB, at reperfusion, 4 h to 2 days after surgery, at discharge, and months after surgery. Neutrophil antigen expression and serum concentration of adhesion molecules, interleukin 8, and C5a (fragment of C5 complement) were analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively.ResultsWith and without CPB, anesthesia and surgery induced decreased LFA-1 (CD11a–CD18), Mac-1 (CD11b–CD18), CD45, and CD54 (intercellular adhesion molecule 1) surface expression and sICAM-1 serum concentrations (allP< 0.001). sL-selectin serum concentration decreased with CPB (P< 0.001) but was not significantly altered in the control. In contrast, CD62L expression increased during CPB (P< 0.001). The time course of all analyzed markers was not significantly different between CPB and control, with the exception of sL-selectin (P= 0.017). One-day preoperative baseline values were reached days to months after surgery. Interleukin 8 and C5a serum concentrations increased after surgery in both the CPB group and the control group.ConclusionsPediatric cardiovascular surgery leads to reduced adhesiveness and activity of circulating neutrophils. This reduction is more pronounced and sustained with CPB. These data may be useful in the assessment of novel therapeutic strategies.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundTreatment of elevated blood pressure is frequently necessary after cardiac surgery to minimize postoperative bleeding and to attenuate afterload changes associated with hypertension. The purpose of this study was to investigate the pharmacodynamics and pharmacokinetics of a short-acting calcium channel antagonist, clevidipine, in the treatment of hypertension in postoperative cardiac surgical patients.MethodsPostoperative cardiac surgical patients were randomized to receive placebo or one of six doses of clevidipine. Hemodynamic parameters were recorded and blood samples were drawn for determination of clevidipine plasma concentrations during infusion and after discontinuation of clevidipine. The concentration–response relation was analyzed using logistic regression, and pharmacokinetic models were applied to the data using population analysis.ResultsThere were significant decreases in mean arterial blood pressure and systemic vascular resistance at doses greater than or equal to 1.37 &mgr;g · kg−1· min−1. There were no changes in heart rate, central venous pressure, pulmonary artery occlusion pressure, or cardiac index with increasing doses of clevidipine. The clevidipine C50value for a 10% or greater decrease in mean arterial pressure was 9.7 &mgr;g/l and for a 20% or greater decrease in mean arterial pressure was 26.3 &mgr;g/l. The pharmacokinetics of clevidipine were best described with a three-compartment model with a volume of distribution of 32.4 l and clearance of 4.3 l/min. The early phase of drug disposition had a half-life of 0.6 min. The context-sensitive half-time is less than 2 min for up to 12 h of administration.ConclusionClevidipine is a calcium channel antagonist with a very short duration of action that effectively decreases systemic vascular resistance and mean arterial pressure without changing heart rate, cardiac index, or cardiac filling pressures.

ISSN:0003-3022    

出版商:OVID    

年代:2002

数据来源: OVID