空气与液体阻力消失法定位硬膜外间隙效果的比较:Meta分析

目的 采用Meta分析法比较气体或液体阻力消失法定位硬膜外间隙的效果.方法 检索Cochrane图书馆、PubMed、EMBASE、中国生物医学文献数据库、中国期刊全文数据库、维普中文科技期刊、万方数字化期刊群等数据库,分别收集空气或液体阻力消失法定位硬膜外间隙的前瞻性临床随机对照研究.采用Cochrane系统评价法评价纳入文献的质量.收集两组患者资料采用RevMan 5.0.1软件进行Meta分析.结果 共纳入7项研究,包括5183例患者.分为空气阻力消失法组(A组)和液体阻力消失法组(L组).与A组比较,L组困难置管发生率、置管误入血管发生率、阻滞不全发生率和术后头痛发生率降低(P＜0.05),一过性异感发生率和穿破硬膜发生率差异无统计学意义(P＞0.05).结论 与空气阻力消失法比较,液体阻力消失法可更准确地定位硬膜外间隙,阻滞效果更好,且并发症较少.     

Posterior epidural space depth: safety of the loss of resistance and hanging drop techniques

We have compared skin to epidural space distance (SED) and tip to tip distance (TTD), a measure of posterior epidural space depth (PESD), in 40 patients with a 27-gauge Whitacre needle after identification of the epidural space using the hanging drop (HD) or loss of resistance (LOR) to air technique. After the LOR technique, TTD was found to be 2 mm greater than that after the HD technique, whereas SED was the same. We conclude that identification of the epidural space can be performed successfully with both techniques, but with a diminished risk of dural damage after LOR compared with the HD technique.      

Localization of lumbar epidural space by loss of resistance and using the Episensor: a comparative study

Since the existence of negative pressure in the epidural space was reported, its technique of localization has undergone changes directed to improve objectivity, reliability and safety. The aim of the present study was to evaluate a new electronic divide to localize the epidural space, i.e. the Episensor (Palex, Spain). To this end, 71 patients, both males and females, undergoing elective urological surgery and in whom catheterization of the lumbar epidural space had been planned, were prospectively evaluated and randomly assigned to two homogeneous groups. In group I (n = 35) the epidural space was localized by the classical technique of loss of resistance, while in group II the Episensor was used. In both groups several technical parameters, the qualification of the operator and the complications of the procedure were evaluated. There were no significant differences between both groups regarding the quality of epidural blockade or the subjective technical difficulty of the operator. The incidence of complications of the technique of puncture was significantly higher in group II (p less than 0.05); the most common were dura mater puncture in 13 group II patients and in one group I patient (p less than 0.001). There was no correlation between the qualification of the operator and the development of complications. It was concluded that the use of Episensor to localize lumbar epidural space did not improve the effectiveness of blockade but increased the iatrogenic effects of the puncture. Our lack of experience with this new technique and the low negative pressure of lumbar epidural space might have been the causes of the poor results, that we consider as initial in the evaluation of this new method.     

Tachyphylaxis associated with repeated epidural injections of lidocaine is not related to changes in distribution or the rate of elimination from the epidural space

The relationship between tachyphylaxis (measured as a decrease in the rate of regression of sensory levels of analgesia) during repeated epidural injections of lidocaine and both the distribution of lidocaine within the epidural space (as measured by spread of simultaneous injection of the tracer technetium-99m diethylenetriaminepentaacetate [99mTc-DTPA]) and elimination of lidocaine from the epidural space (as measured by serum concentrations of lidocaine) was investigated in 18 patients undergoing minor surgery during lumbar epidural analgesia. Twelve patients received four injections of 20 mL of 2% lidocaine at 2-hr intervals. Epidural distribution was assessed by injection of 99mTc-DTPA diluted in saline on the preoperative day and diluted in an equal volume of 2% lidocaine on the morning before surgery and again after the fourth injection of lidocaine 6 hr later. The distribution of 99mTc-DTPA in the epidural space was unchanged during the three measurements despite significant tachyphylaxis in both sensory analgesia and motor blockade (11 of 12 patients had sensory analgesia 2 hr after the first injection in contrast to only 3 of 12 patients during the third injection). In another six patients 20 mL of 2% lidocaine were injected three times at 2-hr intervals before surgery, with measurements of serum concentrations of lidocaine after the first and last injections. Despite tachyphylaxis (no patient had sensory analgesia 2 hr after the third injection), there was no difference in the rate of disappearance of lidocaine from the epidural space as assessed by plasma lidocaine concentration curves during the first and third injection (0.5 +/- 0.1 and 0.3 +/- 0.04 microgram.mL-1.min-1, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of the epidural space in children

We have used an intravenous micro-drip infusion set to identify the epidural space in 350 infants and children. The infusion set was prepared with saline and connected to the hub of an epidural needle. Free dripping of saline was regarded as a sign that the needle tip had entered the epidural space. The overall success rate of this method was 97.7%.     

Systemic absorption of 2% lidocaine from the lumbar epidural space

The curves of lidocaine (LDC) plasma levels versus time were evaluated in a group of 16 patients receiving single epidural injections of 2% LDC for each metamer to be anesthesized. LDC absorption from epidural space is fairly rapid (tmax = 17 +/- 4 min and t1/2a = 6.2 +/- 1.7 min). This results in very shape peak plasma levels (2.97 +/- 0.87 micrograms/ml with 2% LDC). The remaining pharmacokinetic parameters were: Ke = 0.0057 +/- 0.0022 min-1 and Vd = 1.5 +/- 0.5 l/kg. In all patients adequate levels for operation were obtained.     

氯普鲁卡因与利多卡因用于低位硬膜外麻醉的多中心临床研究

目的 比较氯普鲁卡因与利多卡因用于低位硬膜外麻醉的临床效应.方法 择期下腹部或下肢手术病人120例均分为3%氯普鲁卡因组(A组)和2%利多卡因组(B组).硬膜外注入试验剂量5 ml,5 min后一次性注入追加剂量10 ml.观察麻醉起效时间、痛觉消失时间、最高阻滞平面及时间、痛觉恢复时间、运动恢复时间、肌肉松弛程度以及呼吸、循环功能变化.结果 A组达最高阻滞平面时间(12.1±4.0)min,明显短于B组的(15.4±5.4)min;A组改良Bromage评分评1分的时间(56.8±10.9)min、评0分的时间(67.6±16.9)min,均明显短于B组的(69.1±14.1)min和(80.4±20.7)min(P<0.05).结论 氯普鲁卡因用于硬膜外麻醉起效迅速、感觉和运动阻滞效果好,且运动功能恢复快.     

Influence of age on vascular absorption of lidocaine from the epidural space

The purposes of this study were to evaluate the effect of age on the vascular absorption of local anesthetics during epidural anesthesia and to corroborate the clinical observations of other investigators with respect to age. Using the arbitrary definition of significance (P less than 0.05), the maximum serum levels of lidocaine (Csmax) did not differ significantly with age, however, P values were equal to 0.06. Furthermore, the time to Csmax was significantly faster in elderly patients (P less than 0.00001). In conclusion, the mass of local anesthetic solution should be reduced in elderly patients undergoing epidural anesthesia because there is a greater segmental spread, and serum levels of local anesthetics are increased.     

An observational pilot study of a novel loss of resistance syringe for locating the epidural space

BackgroundThe EpiFaith® syringe is a novel loss-of-resistance syringe that utilizes a spring-loaded plunger that automatically moves forward within the syringe when there is a loss of resistance. We evaluated the syringe in a clinical setting among a cohort of pregnant women receiving neuraxial labor analgesia.MethodsIn a non-randomized observational study, four anesthesiologists used the EpiFaith® syringe 10 times each while placing epidural catheters for labor analgesia. The anesthesiologists scored each placement on an 11-point Likert scale (−5 = absolutely worse, 0 = the same, and 5 = absolutely better than using their regular loss-of-resistance syringe technique).ResultsAll 40 neuraxial placements correctly located the epidural space. Air was used in the syringe in 35 of the 40 cases. In 50%, 27.5% and 22.5% of cases the anesthesiologists reported that using the EpiFaith® syringe was better than, the same as, or worse than using their regular syringe, respectively. There were no inadvertent dural punctures.ConclusionsThis feasibility study found that three of the four anesthesiologists scored the EpiFaith® syringe as better or the same as using their regular loss-of-resistance syringe. More extensive studies are required to determine if the EpiFaith® syringe reduces adverse outcomes such as unintentional dural punctures.