Ultrasound vs nerve stimulation multiple injection technique for posterior popliteal sciatic nerve block

In this prospective, randomised, observer-blinded study we evaluated whether ultrasound guidance can shorten the onset time of popliteal sciatic nerve block as compared to nerve stimulation with a multiple injection technique. Forty-four ASA I–III patients undergoing posterior popliteal sciatic nerve block with 20 ml of 0.75% ropivacaine were randomly allocated to nerve stimulation or ultrasound guided nerve block. A blinded observer recorded onset of sensory and motor blocks, success rates, the need for fentanyl intra-operatively, the requirement for general anaesthesia, procedure-related pain, patient satisfaction and side-effects. Onset times for sensory and motor blocks were comparable. The success rate was 100% for ultrasound guided vs 82% for nerve stimulation (p = 0.116). Ultrasound guidance reduced needle redirections (p = 0.01), were associated with less procedural pain (p = 0.002) and required less time to perform (p = 0.002). Ultrasound guidance reduced the time needed for block performance and procedural pain.     

Lateral popliteal sciatic nerve block compared with ankle block for analgesia following foot surgery

The purpose of this study was to compare postoperative analgesia after foot surgery in patients anaesthetised either with popliteal sciatic nerve block or ankle block. In a prospective study, 40 patients scheduled for foot surgery involving osteotomies were allocated randomly into one of two groups. Following induction of general anaesthesia, Group PS (n = 21) received a lateral popliteal sciatic nerve block and Group AB (n = 19) received an ankle block. Both groups received 20 ml bupivacaine 0.5% plain. In group PS 43% required morphine analgesia in the Post Anaesthetic Recovery Room (PAR) compared with 16% in group AB. Postoperative analgesia was assessed using VAS and a pain scale in the PAR and a questionnaire by telephone follow-up on the day after surgery. The ankle block appeared to be more reliable, providing more consistent analgesia in the PAR. Postoperative analgesia in Group PS lasted a median of 18.0 hr and in Group AB lasted 11.5 hr (P < 0.05). Both techniques provided effective analgesia after discharge home and high levels of patient satisfaction.     

Unintentional side error for continuous sciatic nerve block at the popliteal fossa

Among all fields of healthcare about 45% of medical errors occur in the operating theatre. Wrong site procedures remain one of the most preventable medical errors. Unintentional wrong-sided peripheral nerve block is relatively a rare event in anesthesia care. However, the incidence is unknown but each time wrong-sided block occurs it represents a mistake and a potential for harm. The surgical safety checklist was established in 2008 by the world Health organization (WHO) as a part of the "Safe surgery save Lives" initiative. We report in this article a case of wrong sided continuous popliteal sciatic nerve block and discuss the role of the WHO's checklist in preventing wrong side peripheral nerve block and surgery.     

Continuous popliteal sciatic nerve block for outpatient foot surgery--a randomized, controlled trial

BACKGROUND: A major problem in outpatient foot surgery is severe postoperative pain that is not sufficiently treated by peroral analgesics. METHODS: Sixty-three patients underwent foot surgery under spinal anesthesia. Immediately on conclusion of the operation, sciatic and saphenous nerve blocks were performed. The sciatic nerve was blocked in the popliteal fossa with 30 ml of ropivacaine 5 mg ml(-1) and a perineural catheter was passed through the cannula. The patients were randomized to receive either ropivacaine 2 mg ml(-1) (n=30) or saline (n=30) in the catheter through a disposable elastomeric pump with a fixed infusion rate of 5 ml h(-1) for 55 h. RESULTS: Analgesia was excellent until 23 h 44 min (14 h 34 min) in the treatment group and 18 h 16 min (7 h) in the placebo group [mean (SD), P=0.07]. Thereafter, pain was significantly less in the treatment group on the first and second postoperative days (P=0.001). Sleep disturbances because of the pain in the foot were experienced by 25% of the treatment group on the first night at home and by 50% of the control group (P=0.29). There were no differences between the groups in their need for rescue opioid medication. None of the patients had any major problem with the catheter or pump, and none had any toxic effect referable to the technique. CONCLUSION: This randomized, double-blind study shows that continuous blockade of the sciatic nerve in the popliteal fossa reduces postoperative pain and has no untoward effects in a patient group known to experience severe pain after ambulatory surgery.     

Thigh abscess as a complication of continuous popliteal sciatic nerve block

We present a case report of severe localized infection aftercontinuous popliteal sciatic nerve block. The report highlightsthe importance of meticulous asepsis and possibly limiting theduration of catheter use.     

Ultrasound-guided posterior approach to block the sciatic nerve at the popliteal fossa

The recent introduction of ultrasound guidance for locating peripheral nerves and nerve plexi has allowed injection of anesthetic agents to block the sciatic nerve at the popliteal fossa proximal to division, thus preventing damage to adjacent structures, repeated punctures, and multiple nerve stimulations to verify anesthetic diffusion around the nerve. We report the case of a 23-year-old man, ASA I, who underwent reduction and osteosynthesis of a fractured right fibula. Ultrasound was used to guide the needle after identification of the sciatic nerve 10 cm from the knee fold and 3.5 cm deep. When the point of the needle was near the nerve, the nerve stimulator was switched on to 0.5 mA, and when no response was obtained the current was increased to 1.5 mA. The needle was moved slightly (1-2 mm) to produce a plantar flexion (tibial component) that persisted until stimulation had been reduced to 0.4 mA, at which time 30 mL of 1.5% mepivacaine was injected. The sonographic image during injection showed that the anesthetic had surrounded the nerve (donut sign). The motor and sensory block of the sciatic nerve was complete and no adverse events occurred during or after surgery. We conclude that the combination of ultrasound guidance and nerve stimulation allows the sciatic nerve to be located easily. The approach to the point before division of the sciatic nerve can be guaranteed so that puncture of neighboring vessels can be avoided and optimal anesthesia provided.     

Lateral popliteal sciatic nerve block compared with subcutaneous infiltration for analgesia following foot surgery

A new lateral approach to blocking the sciatic nerve in the popliteal fossa is described. In a prospective study, 40 patients scheduled for foot surgery involving osteotomies were allocated randomly into one of two groups following induction of general anaesthesia: group PS (n = 21) received a lateral popliteal sciatic nerve block and group SC (n = 19) received subcutaneous infiltration of the wound. Both groups received 20 ml bupivacaine 0.5% plain. The lateral approach to the popliteal sciatic nerve was found to be an effective, quick, and easy to perform, block. Postoperative analgesia in groups PS lasted a median of 18.0 hr and in group SC lasted 6.3 hr (P < 0.05). The lateral popliteal sciatic nerve block provided effective analgesia following foot surgery and had a high level of patient satisfaction.     

0.5%罗哌卡因用于超声引导侧入路腘窝坐骨神经阻滞的半数有效剂量

目的 确定0.5%罗哌卡因用于超声引导侧入路腘窝坐骨神经阻滞时的半数有效剂量.方法 拟在脊椎-硬膜外联合麻醉下行足踝手术患者23例,性别不限,年龄l9～20岁,体重2～90 kg,ASA分级Ⅰ或Ⅱ级,在超声引导下行侧入路腘窝坐骨神经阻滞,定位成功后注入0.5%罗哌卡因.采用Dixon序贯法进行试验,5%罗哌卡因起始容量为18 ml,若阻滞效果完全,则下一例减少2 ml;若阻滞效果不完全,则下一例增加量2 ml.采用Probit概率单位回归法计算0.5%罗哌卡因超声引导侧入路腘窝坐骨神经阻滞时的半数有效剂量及其95%可信区间(95%CI).结果 0.5%罗哌卡因超声引导侧入路腘窝坐骨神经阻滞的半数有效剂量及其95%CI为13.0(11.3～14.9)ml.结论 0.5%罗哌卡因超声引导侧入路腘窝坐骨神经阻滞的半数有效剂量为13.0ml.     

Continuous sciatic nerve block

A technique of continuous sciatic nerve block is described. The method was used to relieve pain from ischaemic gangrene of the foot for 2 days before below-knee amputation and, combined with a continuous inguinal paravascular block, to provide regional anaesthesia both for the surgery and for the first 2 postoperative days.