Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Comparative Study Clinical TrialIntrathecal ropivacaine for labor analgesia: a comparison with bupivacaine.
Ropivacaine has less potential for central nervous system and cardiovascular toxicity than bupivacaine; in pregnant patients and volunteers, it produces less motor block in equianalgesic doses than bupivacaine. We compared two doses of intrathecal ropivacaine combined with sufentanil with a standard dose of intrathecal bupivacaine plus sufentanil for labor analgesia using a combined spinal-epidural (CSE) technique. In a prospective, randomized, double-blind fashion, 48 patients requesting labor analgesia received either 2.5 mg of intrathecal bupivacaine plus sufentanil 10 microg (B), 2 mg of intrathecal ropivacaine plus sufentanil 10 microg (R2), or 4 mg of intrathecal ropivacaine plus sufentanil 10 microg (R4). Duration of analgesia and side effects, such as motor block, pruritus, hypotension, ephedrine requirements and fetal bradycardia, were recorded. Duration of analgesia (mean +/- SD) was 79+/-30 min for R2, 98+/-19 min for R4, and 92+/-38 min for B (P = not significant). No differences in motor block or side effects were detected among the groups. We conclude that ropivacaine, when combined with sufentanil, is effective for providing CSE labor analgesia and offers no advantage over bupivacaine in the studied doses. ⋯ In this study, we compared a standard dose of intrathecal bupivacaine with sufentanil for combined spinal epidural analgesia with two doses of the new local anesthetic ropivacaine. Both local anesthetics provided similar labor analgesia duration with equivalent side effect profiles in the doses studied.
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Anesthesia and analgesia · Sep 1998
Clinical TrialEffects of cardiopulmonary bypass and deep hypothermic circulatory arrest on the thyroid axis during and after repair of congenital heart defects: preservation by deep hypothermia?
Thyroid function is altered by cardiopulmonary bypass (CPB) in children. To better understand the cause of altered thyroid hormone levels, we compared the effects on the pituitary-thyroid axis of CPB in 23 children undergoing elective repair of congenital heart defects. Twelve patients underwent CPB with moderate hypothermia without a period of deep hypothermic circulatory arrest (DHCA), and eleven underwent CPB with DHCA. Nine blood samples were collected from each patient before, during, and after CPB. Free T3 (FT3), free T4 (FT4), total T3 (TT3), total T4 (TT4), thyrotropin (TSH), and albumin were measured; concentrations of each decreased significantly with the onset of CPB (P < 0.05). There was a greater decline in hormone than in albumin concentrations, which suggests that factors in addition to hemodilution were present (P < 0.05). TSH concentrations in the DHCA group began to increase during cooling, exceeding baseline values after rewarming and after separation from CPB. Patients undergoing CPB without DHCA had persistently low TSH concentrations (P < 0.05). By Postoperative Days 1 and 2, TSH concentrations in both groups were similar and significantly lower than baseline values (P < 0.001). FT3, FT4, TT3, TT4, and albumin all increased during CPB after an initial decrease. Of these, only albumin and FT4 recovered to their baseline values after the initial decrease. Nevertheless, by Postoperative Day 1, both groups demonstrated the "sick" euthyroid syndrome and could not be distinguished from one another. This study demonstrates greater pituitary release of TSH in children undergoing repair of congenital heart defects with DHCA compared with CPB alone, the cause of which could not be determined in this study. However, despite the increase in TSH in the DHCA group, the thyroid hormone concentrations failed to increase appropriately. ⋯ Early after deep hypothermia circulatory arrest, thyrotopin concentrations increase appropriately, responding to decreased concentrations of T3; however, all children undergoing cardiopulmonary bypass eventually develop a "sick" euthyroid syndrome by Postoperative Day 1. Whether this difference represents better protection of neuroendocrine function by deep hypothermic circulatory arrest (relative to cardiopulmonary bypass alone) remains speculative.
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Anesthesia and analgesia · Sep 1998
Clinical TrialPredictive factors of outcome in severely traumatized children.
To identify risk factors associated with death in traumatized children, we prospectively studied 507 consecutive patients (7+/-4 yr) admitted to a level I pediatric trauma center over a 3-yr period. Pediatric Trauma Score (PTS), Glasgow Coma Scale (GCS) score, and Injury Severity Score (ISS) were calculated. Age, injury mechanism, injury pattern, and initial critical care were recorded. Univariate and multivariate analyses were performed for potential risk factors associated with mortality. Receiver operating characteristic curves were used to determine threshold values of variables identified by univariate analysis. Most children suffered from blunt trauma (99.6%), and head trauma was noted in 85%. Median values (range) of GCS scores, PTS, and ISS were 10 (3-15), 7 (-4 to 12), and 16 (3-75), respectively. The mortality rate was 12%. Using multivariate analysis, death was significantly associated with an ISS > or = 25 (odds ratio [OR] 22.2, 95% confidence interval 2.8-174.9), GCS score < or = 7 (OR 4.77, 1.8-12.7), emergency blood transfusion > or = 20 mL/kg (OR 4.3, 2.1-9.1), and PTS < or = 4 (OR 3.7, 1.4-9.7). An ISS > or = 25, GCS score < or = 7, immediate blood transfusion > or = 20 mL/kg, and PTS < or = 4 were significant and independent risk factors of death in an homogenous population of severely injured children. The probability of traumatic death was therefore 0 (95% confidence interval 0-0.0135) in children with no one of these threshold values in the four predictive factors and 0.63 (95% confidence interval 0.47-0.76) in those children with all the threshold values. ⋯ Methods used for evaluating outcome of trauma patients have essentially been derived from adult series, and attempts to apply them to children have usually been inaccurate. Univariate and multivariate analyses were performed to identify risk factors associated with death in severely traumatized children, and Receiver operating characteristic curves were used to determine threshold values.
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Anesthesia and analgesia · Sep 1998
Postanesthesia care unit length of stay: quantifying and assessing dependent factors.
Postanesthesia care unit (PACU) monitoring reduces morbidity and is the standard of care for postsurgical patients. PACUs require large nurse to patient ratios, which contributes to the cost of care. Despite the importance and cost of PACU length of stay (LOS), no standards have been established. We performed an observational study of 340 PACU patients to measure actual and medically appropriate PACU LOS (the time required to achieve a medically stable condition for safe PACU discharge), to identify factors related to LOS, and to create a LOS prediction index. Mean (+/- SD) actual LOS was 95+/-43 min, and appropriate PACU LOS was 71+/-37 min. Appropriate PACU LOS predictors were anesthetic time, anesthetic technique, and amount of intraoperative fluids. Actual LOS was >30 min longer than the medically appropriate LOS for 20% (68 of 340) of the patients. Frequent causes of excessive LOS were waiting for physician release or laboratory or radiographic results. Appropriate LOS may be related primarily to anesthetic factors, and nonmedical issues account for a significant amount of PACU LOS. ⋯ Most patients are stabilized immediately after surgery in a postanesthesia care unit (PACU) until their discharge to a hospital ward. However, there are no standards for appropriate PACU length of stay (LOS). In this study, we measured actual and appropriate PACU LOSs and evaluated clinical factors that may influence PACU LOS.