Spinal anesthesia using hyperbaric 0.75% versus hyperbaric 1% bupivacaine for cesarean section

Although 0.75% hyperbaric bupivacaine is commonly administered to provide spinal anesthesia for cesarean section in the United States, in some countries, only the 1% hyperbaric solution of spinal bupivacaine is available. The aim of this study was to compare 0.75% with 1% hyperbaric spinal bupivacaine for cesarean section. In this prospective study, 50 patients undergoing elective cesarean section were randomized to receive a spinal anesthetic with either 1.5 mL of 0.75% bupivacaine (n = 25) or 1.125 mL of 1% bupivacaine (n = 25). There were no statistically significant differences in patient demographics, time to onset of block, or intraoperative pain. All patients had a successful block for surgery. The time from injection of the spinal anesthetic to first request for pain medication in the postanesthesia care unit was longer in the women who received 0.75% bupivacaine (4.3 vs 3 h; P < 0.05). Six women (24%) who received 1% bupivacaine versus one woman (4%) who received 0.75% bupivacaine complained of postoperative backache (P < 0.05). In addition, postdural puncture headache occurred in four women, all of whom received 1% bupivacaine (P = 0.04). In conclusion, our data suggest that 0.75% bupivacaine results in fewer postoperative problems and offers several significant benefits compared with the 1% concentration. IMPLICATIONS: Although 0.75% bupivacaine is usually used to provide spinal anesthesia for cesarean section in the United States, a more concentrated solution is popular in Europe. In this study, we compared 0.75% bupivacaine with 1% bupivacaine when administered for cesarean section and found that the 0.75% solution offers several significant benefits.     

硬膜外麻醉与腰硬联合麻醉在剖宫产术中应用效果比较

近年来,剖宫产率呈明显上升趋势,当前我国大部分城市医院剖产率达到40.00%～50.00%.剖宫产术的安全性和术中的并发症越来越受到社会的广泛关注.为比较硬膜外麻醉(CEA)和腰硬联合麻醉(CSEA)在剖宫产术中麻醉效果、不良反应以及对产妇、新生儿的影响.对宜都市妇幼保健院2006年1月-2009年1月剖宫产术的单胎初产妇1600)名采用两种不同的麻醉方法的效果进行比较分析,现报告如下.     

Unilateral spinal anaesthesia with hyperbaric bupivacaine

BACKGROUND: The dosage of local anaesthetic and the time the patient must be kept in the lateral decubitus position for a unilateral spinal anaesthesia is not known. The aim of this study was to determine the ideal dosage of hyperbaric bupivacaine and the time required for the lateral decubitus position for a unilateral spinal block. METHODS: Ninety patients who were scheduled to receive spinal block for surgery in the lower extremity were randomised into 9 groups (n = 10). The spinal block was performed through the L4-L5 intervertebral space with the patient in the lateral decubitus position. Patients in groups Ia, Ib, Ic; IIa, IIb, IIc; IIIa, IIIb, IIIc received 1.5 ml of 0.5%, 2 ml of 0.5%, and 2.5 ml of 0.5% hyperbaric bupivacaine solutions, respectively. The patients were turned to the supine position for 5 min after the injection in groups Ia, IIa, IIIa, 10 min after the injection in groups Ib, IIb, IIIb, and 15 min after the injection in groups Ic, IIc, IIIc. The onset and regression of sensory and motor block were checked and compared between the dependent and non-dependent sides in each group. RESULTS: The rate of block progression of the non-dependent side was higher in the groups receiving 2.5 ml 0.5% hyperbaric bupivacaine solution than in the other groups; at the same time the level of block was higher and the duration of block was longer. The incidence of hypotension was 10-20% in these groups. In the 2 ml 0.5% hyperbaric bupivacaine solution groups, a satisfactory block level and duration of anaesthesia for surgery was obtained. The rate of block progression to non-dependent side in the groups receiving 1.5 ml of 0.5% hyperbaric bupivacaine solution was lower than the other groups, but the duration of block was shorter and the level of block was lower than the other groups. CONCLUSION: For unilateral spinal anaesthesia in lower extremity operations, 2ml 0.5% hyperbaric bupivacaine solution for operations above the knee and 1.5 ml 0.5% hyperbaric bupivacaine solution for operations below the knee and keeping the patients for 10 min in the lateral decubitus position were found to be appropriate.     

Peridural anesthesia versus subarachnoid anesthesia in cesarean section. Prospective clinical study

OBJECTIVE: To compare technical and clinical differences between epidural and spinal anesthesia for cesarean section. STUDY DESIGN: Randomized prospective trial. PATIENTS AND METHODS: 64 pregnant women at term scheduled for elective cesarean section. Two groups were randomized: A) PD Group (n = 32): continuous epidural anesthesia by administration of bupivacaine 0.5% plus epinephrine 1/400,000 via an epidural catheter. Epidural morphine 3 mg was administered at the end of surgery. B) SP Group (n = 32): "single shot" spinal anesthesia by intrathecal administration of hyperbaric 1% bupivacaine 1-1.4 ml plus morphine 0.2 mg. The pin prick block level reached T2-T6 at incision time. DATA COLLECTION: 1) Time from the beginning of anesthesia to surgical incision. 2) Hypotension episodes. 3) Ephedrine consumption. 4) Intraoperative discomfort at delivery, traction and uterine manipulation, peritoneal toilette. 5) Nausea and vomiting. 6) Apgar score. 7) Postoperative headache. RESULTS: Women in the SP group had more hypotensive episodes (81% vs 53%: p < 0.05) and more ephedrine consumption with a large individual variability (29.12 mg +/- 20.4 vs 12.83 +/- 13.8: p < 0.01) when compared to PD group, without any difference in the Apgar score. The SP group required less time consumption (10.5 min. +/- 6.7 vs 35.9 min. +/- 17.3: p < 0.01) and had less intraoperative discomfort with less analgesic and/or sedative drugs consumption (9.7% vs 29%: p < 0.05) and less vomiting (3% vs 22.5%: p < 0.05). No postoperative headache was noticed in both groups. CONCLUSIONS: With the described pharmacological and technical approach, spinal anesthesia is more suitable than continuous epidural technique for cesarean section, unless contraindicated.     

The effect of epinephrine on small-dose hyperbaric bupivacaine spinal anesthesia: clinical implications for ambulatory surgery

The effect of adding epinephrine to small doses of spinal bupivacaine on the duration of sensory motor block has not been carefully investigated. Twelve volunteers underwent hyperbaric bupivacaine spinal anesthesia (7.5 mg) with and without epinephrine (0.2 mg) in a randomized, double-blind, cross-over fashion. Sensory block was assessed with pinprick, transcutaneous electrical stimulation (TES) equivalent to surgical stimulation (at umbilicus, pubis, knee, and ankle), and tolerance of a pneumatic thigh tourniquet. Motor block was assessed with isometric force dynamometry. Discharge criteria were defined as return of pinprick sensation to dermatome S2, ability to ambulate, and ability to urinate. Extent of sensory block to pinprick over time was unaffected by the addition of epinephrine. However, epinephrine prolonged tolerance of TES at the pubis, knee, and ankle (33-48 min, P < 0.05) and of thigh tourniquet (30 min, P < 0.01). Motor block was prolonged by epinephrine at the quadriceps and gastrocnemius muscles (by 23 and 51 min, respectively, P < 0.002). Achievement of discharge criteria was prolonged by 48 min by the addition of epinephrine (P < 0.01). Thus, epinephrine may prolong surgical anesthesia for lower abdominal and lower extremity surgery and delay time until patients achieve discharge criteria. Implications: Using a cross-over study design, 12 volunteers underwent bupivacaine spinal anesthesia with and without epinephrine. This study suggests that adding epinephrine to bupivacaine may prolong surgical anesthesia and also delay patients' discharge.     

Spinal anesthesia for cesarean section. 1963

Safety in spinal anesthesia for cesarean section is achieved by strict adherence to the cardinal principles of proper evaluation and selection of patients, the use of prophylactic vasopressors, preanesthetic establishment of a reliable intravenous channel, small doses of the local anesthetic, close monitoring and maintenance of systolic blood pressure above 100 mm. Hg, and avoidance of ergot compounds in the presence of vasopressors.     

Adequacy of general anesthesia for cesarean section

Ejaculated spermatozoa from four different boars were used to evaluate the acrosome reaction during in vitro fertilization with homologous ovulated oocytes. The acrosome reaction was assessed according to a peroxidase-labeling peanut agglutinin method and a triple-stain technique. An increase in the proportion of living sperm with reacted acrosomes was observed after preincubation and 2 hr of coincubation (P < 0.05). The percentage of true acrosome-reacted sperm remained reasonably constant throughout coincubation. In vitro penetration rates of oocytes varied among boars, but no relationship was found between fertilization rates of oocytes and maximum percentages of acrosome reacted living sperm.     

Intrathecal opioids provide satisfactory conditions in labor analgesia and spinal anesthesia for cesarean section

Metastases is an uncommon cause of tumors in the sinonasal region. We report a patient with hepatocellular carcinoma which metastasized to the nasal cavity.     

Combined spinal and epidural anesthesia for cesarean section in a parturient with moyamoya disease

We present the case of a parturient with moyamoya disease admitted to the hospital for elective cesarean section. Combined spinal and epidural technique was chosen because it allows better analgesia than epidural anesthesia and more hemodynamic stability than either general or spinal anesthesia. Ropivacaine was the local anesthetic of choice for the epidural portion because of the wide sensory-motor dissociation, thus preserving adequate respiration in the case of a high block.     

CSE vs. augmented epidural anesthesia for cesarean section. Spinal and epidural anesthesia with bupivacaine 0.5% "isobar" require augmentation

Incomplete anaesthesia is a major clinical problem both in single spinal and in single epidural anaesthesia. The clinical efficacy of epidural anaesthesia with augmentation (aEA) and combined epidural and spinal anesthesia (CSE) for cesarean section was investigated in a prospective randomized study on 45 patients. METHODS: Anaesthesia extending up to Th5 was aimed for. Depending on the patient's height, epidural anaesthesia was administered with a dose of 18-22 ml 0.5% bupivacaine and spinal anaesthesia with a dose of 11-15 mg 0.5% bupivacaine. Augmentation was carried out in all cases in epidural anaesthesia, initially with 7.5 ml 1% Lidocaine with epinephrine 1:400,000, raised by 1.5 ml per missing segment. The epidural reinjection in CSE was carried out as necessary with 9.5-15 ml 1% lidocaine with epinephrine, depending on the height and difference from the segment Th5. RESULTS: The extension of anaesthesia achieved in epidural anaesthesia after an initial dose of 101.8 mg bupivacaine and augmenting dose of 99 mg lidocaine reached the segment Th5. The primary spinal anaesthesia dose up to 15 mg corresponding to height led to a segmental extension to a maximum of Th3 under CSE. Augmentation was necessary in 13 patients; in 5 cases because of inadequate extent of anaesthesia and 8 cases because of pain resulting from premature reversion. The augmenting dose required was 13.9 ml. Readiness for operation was attained after 19.8 min (aEA) and after 10.5 min (CSE). No patient required analgesics before delivery. The additional analgesic requirement during operation was 63.6% (aEA) and 39.1% (CSE). Taking into account pain in the area of surgery, the requirement of analgesics was 50% (aEA) vs. 17.4% (CSE). Antiemetics were required in 18.2 (aEA) and in 65.2% (CSE). The systolic blood pressure fell by 17.7% (aEA) and in 30.3% (CSE). The minimum systolic pressure was observed after 13.4 min in aEA, and after 9.5 min in CSE. The APGAR score and the umbilical pH did not show any differences. General anaesthesia was not required in any case.     

Midazolam versus placebo before spinal anesthesia

The goal of this randomized, double blind and multicentric study was to compare the effects of midazolam (M) and placebo (P) administered by titration before puncture for spinal anaesthesia on the comfort of 211 patients scheduled for elective surgery after oral premedication with hydroxyzine. The administered dose of midazolam was 3.4 +/- 1.3 mg (mean +/- SD). Anxiety was nil in 92% of the patients of the M group and in 64% of the patients of the P group (p < 0.001) and memorization of the pain of the puncture was reported in 34% of the patients of the M group and in 66% of the patients of the P group (p < 0.001). However cooperation of the patient and easiness of the puncture were similar in both groups. In conclusion titrated sedation with midazolam before puncture for spinal anaesthesia increases the comfort of the patient.     

Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload

We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. Maternal uterine circulation was measured using Doppler ultrasound in 11 parturients before and after spinal anaesthesia. There was a lower incidence of severe hypotension in the ephedrine group compared with the fluid group (35% vs. 65%, p = 0.04), although the incidence of moderate hypotension was similar. Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section.     

Diamorphine-bupivacaine mixture compared with plain bupivacaine for analgesia

We have studied the efficacy of two extradural infusions (10 ml h-1) in 50 patients in active labour. Patients in the diamorphine group (n = 25) received 0.0625% plain bupivacaine 6.25 mg h-1 mixed with 0.005% diamorphine 0.5 mg h-1 and those in the control group (n = 25) received 0.125% plain bupivacaine 12.5 mg h-1. Both groups received intermittent "top-ups" of 0.25% bupivacaine 10 ml when indicated. Although median pain scores during the infusion were similar in both groups, patients in the diamorphine group indicated greater satisfaction with the infusion (88% very satisfied, compared with 52% in the control group (P < 0.02)). There were no differences in the incidence of hypotension, instrumental vaginal delivery, number of "top-ups", duration of the second stage or extent of motor block. However, patients in the diamorphine group had a high incidence of pruritus (44%, compared with 0% in the control group (P < 0.01)).     

Epidural anesthesia for cesarean section in a twin pregnant patient with severe aortic stenosis

A 35-year-old twin primigravida with aortic stenosis underwent cesarean section under epidural anesthesia. She had her ventricular septal defect repaired at 3 years of age. Preoperative ultrasonic study revealed severe aortic stenosis in which valve area was 0.77 cm2 and pressure gradient between the left ventricle and the aorta was 80 mmHg. We persuaded her and her husband to discontinue pregnancy and recommended aortic valve replacement surgery. They rejected our suggestions, and cesarean section was scheduled at 29 weeks' gestation. We chose epidural anesthesia. A 20-gauge catheter and a pulmonary artery catheter were inserted to monitor the hemodynamics. Two lumbar epidural catheters were placed at the L 1-2 and L 4-5 intervertebral spaces. Sixteen milliliters of 1.5% mepivacaine were injected, producing anesthesia up to T 6 level. The babies were delivered, and postnatal conditions of both infants were satisfactory. Methoxamine 1 mg was administered four times when systolic blood pressure decreased to 80 mmHg following deliveries. Otherwise, peripartal hemodynamics was stable, and she was transferred to the intensive care unit (ICU). Postoperative pain was controlled with epidural infusion of fentanyl. She did not complain of chest pain perioperatively and was discharged from the ICU next day.