Imbelloni Luiz Eduardo, Vieira Eneida Maria, Rocha Ana, Gouveia Marildo Assunção, Cordeiro José Antônio
Clínica São Bernardo, Rio de Janeiro, RJ, Brazil.
Rev Bras Anestesiol. 2003 Jun;53(3):322-30.
Spinal block for cesarean section was described few years after the first report of spinal anesthesia by Bier in 1899. It was not until the last 5 years that spinal anesthesia has become the most frequent anesthetic method for cesarean section at our hospital. This prospective study aimed at evaluating 0.5% spinal isobaric bupivacaine for cesarean section, injected after fentanyl and morphine, in the lateral position, and at correlating the incidence of hemodynamic changes and cephalad spread with different volumes.
Participated in this study 100 patients undergoing spinal anesthesia for elective cesarean delivery who were randomly allocated into three groups to receive: 4 ml (20 mg), 3 ml (15 mg) or 2.5 ml (12.5 mg) of 0.5% isobaric bupivacaine after 25 microg fentanyl plus 50 microg morphine. The following parameters were evaluated and compared: analgesia and motor block onset, cephalad spread of analgesia, cardiovascular changes and the incidence of nausea and vomiting.
The three volumes of 0.5% isobaric bupivacaine produced comparable effects. Onset was longer for the lowest dose. There were no differences in cephalad spread, number of patients with high cervical levels, cardiovascular changes and post dural puncture headache. Maximum analgesic level was T4 (range: T3-T6) with 4 ml, T4 (range: T4-T11) with 3 ml and T4 (range: T4-T8) with 2.5 ml. No patient required ephedrine to treat arterial hypotension. Motor block was incomplete for all patients. One patient developed post dural puncture headache.
Results of this study confirm that 0.5% isobaric bupivacaine, following fentanyl and morphine injected with separate syringes and in the lateral position, in doses of 2.5, 3 and 4 ml provides a fast and effective anesthesia for cesarean section.
1899年比尔首次报道蛛网膜下腔麻醉后数年，剖宫产蛛网膜下腔阻滞才被描述。直到最近5年，蛛网膜下腔麻醉才成为我院剖宫产最常用的麻醉方法。本前瞻性研究旨在评估在侧卧位下，于芬太尼和吗啡之后注射0.5%等比重布比卡因用于剖宫产的效果，并将血流动力学变化及头向扩散的发生率与不同剂量相关联。
100例行择期剖宫产蛛网膜下腔麻醉的患者参与本研究，随机分为三组，分别接受：在25微克芬太尼加50微克吗啡之后，注射4毫升（20毫克）、3毫升（15毫克）或2.5毫升（12.5毫克）的0.5%等比重布比卡因。评估并比较以下参数：镇痛和运动阻滞起效时间、镇痛的头向扩散、心血管变化以及恶心呕吐的发生率。
0.5%等比重布比卡因的三个剂量产生了相当的效果。最低剂量的起效时间更长。在头向扩散、高颈段水平患者数量、心血管变化及腰穿后头痛方面无差异。最大镇痛平面4毫升组为T4（范围：T3 - T6），3毫升组为T4（范围：T4 - T11），2.5毫升组为T4（范围：T4 - T8）。无一例患者需要麻黄碱治疗动脉低血压。所有患者的运动阻滞均不完全。1例患者发生了腰穿后头痛。
本研究结果证实，在侧卧位下，用单独注射器注射芬太尼和吗啡之后，2.5毫升、3毫升和4毫升剂量的0.5%等比重布比卡因可为剖宫产提供快速有效的麻醉。
