A report on 107 cases of obturator nerve block

The obturator nerve passes in close proximity to the inferolateral bladder wall. Transurethral resection of bladder tumors close to these areas may stimulate the obturator nerve, causing violent adductor contraction and possible inadvertent bladder perforation. To avoid this reaction, local anesthetic blockade of the obturator nerve as it passes through the obturator canal is effective to stop adductor spasm during spinal anesthesia. We performed obturator nerve block in 107 cases by use of insulated needle and nerve stimulator, and measured the depth of the obturator nerve and that of the pubic tubercle. Obesity index was positively correlated with the depth of the obturator nerve as well as the pubic tubercle. However, no correlation was found between the obesity index and the difference of the depth of the obturator nerve and the depth of the pubic tubercle. It is suggested that if the needle is advanced in the direction of the obturator canal about 40mm further after reaching the pubic tubercle, the needle reaches the obturator nerve.     

A new inguinal approach for the obturator nerve block: anatomical and randomized clinical studies

BACKGROUND: Obturator nerve block is highly recommended for knee surgery in addition to a femoral nerve block. The main disadvantage of the classic approach at the pubic tubercle is low patient acceptance due to pain and discomfort. The authors hypothesized that the use of a new inguinal obturator nerve block technique would reduce pain and discomfort in patients. METHODS: The inguinal approach was simulated in five fresh cadavers. Injection of latex was performed in two cadavers. The location of the needle and the extent of latex solution were analyzed. Fifty patients scheduled to undergo arthroscopic knee surgery were randomly assigned to receive obturator nerve block using either the inguinal (n = 25) or the pubic tubercle approach (n = 25). RESULTS: In all cadavers, the needle was close to the obturator nerve branches, which were surrounded by the latex solution. In the clinical study, visual analog scale pain scores and discomfort of block placement were significantly lower in the inguinal group compared with the pubic tubercle group (P < 0.01). In the inguinal group, there was a significant decrease in block performance time (P < 0.05) and in bolus of propofol and fentanyl used for the procedure (P < 0.01). Twenty minutes after application of the block, adductor strength decrease, occurrence, and location of cutaneous distribution of the obturator nerve were not significantly different between the groups. The incidence of minor complications was significantly increased in the pubic tubercle group (P < 0.05). No major complications were observed. CONCLUSIONS: The new inguinal approach decreases patient discomfort and pain of block placement as well as the time and sedation and analgesics required for a similar quality of sensory and motor block compared with the pubic tubercle approach.     

A New Inguinal Approach for the Obturator Nerve Block: Anatomical and Randomized Clinical Studies

Background: Obturator nerve block is highly recommended for knee surgery in addition to a femoral nerve block. The main disadvantage of the classic approach at the pubic tubercle is low patient acceptance due to pain and discomfort. The authors hypothesized that the use of a new inguinal obturator nerve block technique would reduce pain and discomfort in patients.

Methods: The inguinal approach was simulated in five fresh cadavers. Injection of latex was performed in two cadavers. The location of the needle and the extent of latex solution were analyzed. Fifty patients scheduled to undergo arthroscopic knee surgery were randomly assigned to receive obturator nerve block using either the inguinal (n = 25) or the pubic tubercle approach (n = 25).

Results: In all cadavers, the needle was close to the obturator nerve branches, which were surrounded by the latex solution. In the clinical study, visual analog scale pain scores and discomfort of block placement were significantly lower in the inguinal group compared with the pubic tubercle group (P < 0.01). In the inguinal group, there was a significant decrease in block performance time (P < 0.05) and in bolus of propofol and fentanyl used for the procedure (P < 0.01). Twenty minutes after application of the block, adductor strength decrease, occurrence, and location of cutaneous distribution of the obturator nerve were not significantly different between the groups. The incidence of minor complications was significantly increased in the pubic tubercle group (P < 0.05). No major complications were observed.     

Interadductor approach to obturator nerve block for transurethral resection procedure: comparison with traditional approach

Purpose. We compared the interadductor approach of obturator nerve block with the traditional approach in terms of the insertion-adductor contraction interval (ICI), success rate, completion of the block, and plasma lidocaine concentration. Methods. An obturator nerve block by the interadductor approach was performed by needle insertion 1 cm behind the adductor longus tendon and 2 cm lateral to the pubic arch in 12 patients, and by the traditional approach in 12 patients. Results. The ICI with the interadductor approach was significantly shorter than that with the traditional approach. The success rate, completion of the block, and plasma lidocaine concentrations were similar with both approaches. Conclusion. The interadductor approach can provide faster identification of the obturator nerve than the traditional approach. Received: January 29, 2001 / Accepted: December 12, 2001     

逆行耻骨上支髓内螺钉固定应用解剖研究

目的探讨耻骨上支髓内螺钉的正确进钉方法和位置,为临床应用提供解剖学基础。方法解剖6具成人尸体,制成骨性骨盆标本。在直视下,以克氏针模拟逆行耻骨上支髓内螺钉固定法。分别测量钉长、进钉点与耻骨结节的关系、螺钉与两侧髂前上棘和耻骨结节构成平面的夹角、与矢状面的夹角及耻骨上支直径等。结果对于耻骨上支内1／2、外1／2的骨折,平均钉长、螺钉与两侧髂前上棘和耻骨结节构成平面及矢状面的夹角,最窄处直径为皆有差异。结论耻骨上支髓内螺钉固定对于耻骨支不同部位的骨折进钉点和进钉方向不同,用于治疗骨盆前环的耻骨支骨折是安全、可行的。     

Magnetic resonance imaging of the distribution of local anesthetic during the three-in-one block

The three-in-one technique of simultaneously blocking the femoral, the lateral femoral cutaneous (LFC), and the obturator nerves by a single injection of a local anesthetic was first described in 1973, and it was suggested that the underlying mechanism was one of cephalad spread resulting in a blockade of the lumbar plexus. Today, the technique is widely used in surgery and pain management of the lower limb. Many investigators have, however, reported suboptimal analgesia levels, particularly in the obturator nerve. The purpose of this prospective study was to trace the distribution of a local anesthetic during a three-in-one block by means of magnetic resonance imaging (MRI). Seven patients scheduled for surgery of the lower limb were analyzed with the aid of a primary MRI and then received three-in-one blocks using 30 mL of bupivacaine 0.5% under the guidance of a nerve stimulator. A secondary MRI was performed to determine the distribution pattern of the local anesthetic. It emerged that the local anesthetic blocks the femoral nerve directly, the LFC nerve through lateral spread, and the anterior branch of the obturator nerve by slightly spreading in a medial direction. No involvement of the proximal and posterior portions of the obturator nerve was observed, nor was there any cephalad spread that could have resulted in a lumbar plexus blockade. We therefore conclude that the basis of the three-in-one block is confined to lateral, medial, and caudal spread of the local anesthetic, which effectively blocks the femoral and LFC nerves, as well as the distal anterior branch of the obturator nerve. IMPLICATIONS: We demonstrate by using magnetic resonance imaging that the mechanism of a three-in-one block is one of lateral, caudal, and slight medial spread of a local anesthetic with subsequent blockade of the femoral, the lateral femoral cutaneous, and the anterior branch of the obturator nerves. It does not involve cephalad spread of the local anesthetic with blockade of the lumbar plexus.     

Confirmation of caudal needle placement using nerve stimulation.

BACKGROUND: The study was designed to examine a new method of confirming proper caudal needle placement using nerve stimulation. METHODS: Thirty-two pediatric patients were studied. A 22-gauge insulated needle was inserted into the caudal canal via the sacral notch until a "pop" was felt. The needle placement was classified as correct or incorrect depending upon the presence or absence of anal sphincter contraction (S2-S4) to electrical simulation (1 to 10 mA). RESULTS: Three patients were excluded, two because they inadvertently received neuromuscular blockers and one because the patient's anatomy precluded any attempt at a caudal block. The sensitivity and specificity of the test were both 100% in predicting clinical outcomes of the caudal block. Six patients had a negative stimulation test after the first attempt to place the needle. Four of these went on to receive a second attempt of needle insertion after a subcutaneous bulge or resistance to local anesthetic injection were observed. Following needle reinsertion, positive stimulation tests were elicited. These patients received the local anesthetic injection with ease and had good analgesia postoperatively. No attempt was made to reinsert the needle in the remaining two patients with a negative stimulation test, as they did not show subcutaneous bulge or resistance upon injection. These patients had poor analgesia postoperatively. The positive predictive value of the test was greater than the presence of a "pop" alone (P < 0.05) but not significantly different (P = 0.492) over the presence of "pop" and easy injection. CONCLUSION: This test may be used as a teaching and adjuvant tool in performing caudal block.     

Sonographic imaging of the obturator nerve for regional block

BACKGROUND AND OBJECTIVES: Today, there is a growing appreciation of the importance of the obturator nerve in clinical anesthesia. The aim of this study is to describe the ultrasound appearance of the obturator nerve for potential utility in guiding these nerve blocks. METHODS: We scanned left and right inguinal regions of 20 volunteers lateral and distal to the pubic tubercle (PT) and assessed visibility, size and shape, and depth from the skin of common obturator nerves and their associated divisions. In addition to the volunteer study, we retrospectively reviewed a clinical series of obturator nerve blocks performed with ultrasound guidance and nerve stimulation. RESULTS: The obturator nerve can be sonographically visualized by scanning along the known course of the nerve; the anterior division characteristically converges toward the posterior division along the lateral border of the adductor brevis muscle to form the common obturator nerve more proximally. In the set of 20 volunteers, 25% (10/40) of common, 85% (34/40) of anterior, and 87.5% (35/40) of posterior obturator nerves were sonographically identified. The common obturator nerve was visualized 1.3 +/- 1.5 cm distal and 2.3 +/- 1.2 cm lateral to the PT. Divisions were visualized 2.1 +/- 2.0 cm distal and 2.1 +/- 1.2 cm lateral to the PT. The nerves (common, anterior, and posterior) averaged 2.7 +/- 1.2 mm, 1.4 +/- 0.6 mm, and 1.7 +/- 0.6 mm in anterior-posterior dimension and 9.0 +/- 4.3 mm, 9.6 +/- 3.9 mm, and 10.9 +/- 4.1 mm in medial-lateral dimension and were 25.9 +/- 7.6 mm, 15.5 +/- 3.9 mm, and 29.3 +/- 7.9 mm below the skin surface. The common obturator nerve and its anterior and posterior divisions are all relatively flat nerves with average anterior-posterior/medial-lateral dimension ratios of 0.32, 0.18, and 0.18, respectively. In the clinical series, nerve identification was confirmed with nerve stimulation (n = 6 block procedures, mean threshold stimulating current for evoked adductor contraction = 0.70 +/- 0.14 mA). CONCLUSIONS: The obturator nerve and its divisions are the flattest peripheral nerves yet described with ultrasound imaging. Knowledge of the obturator nerve's ultrasound appearance facilitates localization of this nerve for regional block and may increase success of such procedures.     

Interscalene block with a nerve stimulator: a deltoid motor response is a satisfactory endpoint for successful block

BACKGROUND AND OBJECTIVES: The interscalene brachial plexus block (ISB) is an effective and well-established anesthetic technique for shoulder surgery. Using nerve stimulation as an aid in block placement, a motor response (twitch) in the biceps or a more distal upper limb muscle has been recommended to indicate accurate needle placement. Our clinical experience, as well as anatomic reasoning, suggests that a deltoid twitch may be just as effective as one in the biceps for predicting successful block. This prospective clinical study was undertaken to compare a deltoid with a biceps twitch with respect to onset and success of motor block. METHODS: A total of 160 patients scheduled for shoulder surgery were studied prospectively. Interscalene blocks were performed using neurostimulation according to our standard technique. Twitches of the deltoid or biceps or both, whichever appeared first, were accepted and used as the endpoint for needle placement and injection of local anesthetic. Motor block success, i.e., patient inability to lift the arm against gravity, and minutes to motor block onset were recorded. RESULTS: There was 1 failed motor block in the deltoid group and none in the other groups (not a statistically significant difference). When the same local anesthetic was used, there were no statistically significant differences in onset times between the biceps, deltoid, or biceps/deltoid groups. CONCLUSIONS: A deltoid twitch is as effective as a biceps twitch in determining accurate needle placement for ISB and in predicting successful motor block. Acceptance of a deltoid twitch during ISB eliminates the need for further probing and may translate into better patient acceptance and in a smaller risk of needle-induced nerve damage.     

Management of persistent groin pain after transobturator slings

Prolonged groin pain after transobturator tape is uncommon. Three women reported groin pain that had not improved by 3 months postoperatively. Combined steroid and local anesthetic was effective for pain relief in all patients. The differential diagnosis of persistent groin pain after transobturator tape includes adductor muscle strain, osteitis pubis, obturator/groin abscess, structural adhesions, and inflammation, edema or nerve entrapment of the anterior branch of the obturator nerve. No side effects of treatment were noted. Patients that do not respond to local injection may require mesh dissection and excision.     

An evaluation of the cutaneous distribution after obturator nerve block.

In 1973, Winnie et al. introduced the inguinal paravascular three-in-one block, which allegedly provides anesthesia of three nerves--the femoral, lateral cutaneous femoral, and obturator nerves--with a single injection. This concept was undisputed until the success of the obturator nerve block was reassessed by using evidence of adductor weakness rather than cutaneous sensory blockade, the latter being variable in its distribution and often absent. We performed this study, therefore, to evaluate the area of sensory loss produced by direct injection of local anesthetic around the obturator nerve. A selective obturator nerve block with 7 mL of 0.75% ropivacaine was performed in 30 patients scheduled for knee surgery. Sensory deficit and adductor strength were evaluated for 30 min by using sensory tests (cold and light-touch perception) and the pressure generated by the patient's squeezing a blood pressure cuff placed between the knees. Subsequently, a three-in-one block was performed, and the sensory deficit was reassessed. The obturator nerve block was successful in 100% of cases. The strength of adductors decreased by 77% +/- 17% (mean +/- SD). In 17 patients (57%), there was no cutaneous contribution of the obturator nerve. The remaining 7 patients (23%) had an area of hypoesthesia (cold sensation was blunt but still present) on the superior part of the popliteal fossa, and the other 6 (20%) had sensory deficit located at the medial aspect of the thigh. The three-in-one block resulted in blockade of the lateral aspect of the thigh in 87% of cases, whereas the anteromedial aspect was always anesthetized. By use of magnetic resonance imaging in eight volunteers, we demonstrated that the obturator nerve has already divided into its two branches at the site of local anesthetic injection. However, the injection of blue dye after having simulated the technique in five cadavers showed that the fluid regularly spread to both branches. We conclude that after three-in-one block, a femoral nerve block may have been assessed as an obturator nerve block in 100% of cases when testing the cutaneous distribution of the obturator nerve on the medial aspect of the thigh. IMPLICATIONS: Previous studies reporting an incidence of obturator nerve block after three-in-one block may have mistaken a femoral nerve block for an obturator nerve block in 100% of cases when the cutaneous distribution of the obturator nerve was assessed on the medial aspect of the thigh. The only way to effectively evaluate obturator nerve function is to assess adductor strength.     

Corona Mortis血管解剖学研究及其临床意义

目的:探讨闭孔血管和髂外血管在腹股沟区的分支,为减少髂腹股沟入路术中出血提供解剖学基础。方法:对25具新鲜中国成人尸体标本共50侧半骨盆进行解剖学研究,观测闭孔血管和髂外血管在腹股沟区的分支及其吻合支(CoronaMortis血管)的大小、出现率、吻合血管行径和吻合血管至耻骨联合的距离。结果:72%(36侧)耻骨上支表面至少存在1条血管吻合支,其中28%(14侧)存在2条或3条血管吻合支,24%(12侧)同时存在动脉吻合支和静脉吻合支。耻骨上支表面的血管吻合支平均直径2.6mm(2.0～4.2mm)。血管吻合支紧贴耻骨上支或髂耻隆起,几乎垂直地下行于髋臼窝壁或耻骨支后方,经闭膜管出盆腔,血管吻合支与耻骨联合的平均距离52mm(38～68mm)。在此区域手术以及髋臼或骨盆前环骨折极易损伤CoronaMortis血管。结论:闭孔血管和髂外血管的吻合支较粗,出现率高,位于耻骨上支表面。髂腹股沟手术入路应特别注意CoronaMortis血管的存在。     

An anatomical study of corona mortis and its clinical significance

Objective: To provide detailed information of corona mortis for ilioinguinal approach as an anterior approach to the acetabulum and pelvis. Methods: The course, branches and distribution of the vascular connection between the obturator system and the external iliac or inferior epigastric systems located over the superior pubic ramus were observed on 50 hemipelvises with intact soft tissues. Results：During the dissections, 72 % of the cadavericsides had at least one communicating vessel between the obturator system and the external lilac or inferior epigastric systems on the superior pubic ramus. The average diameter of the connecting vessel was 2.6 nun (range, 2.0-4.2 mm). It coursed over the superior pubic ramus or iliopubic eminence vertically to enter the obturator foramen and exit the pelvis. The average distance from pubic symphysis to the vascular connections between the obturator and external iliac systems was 52 nun ( range, 38-68 ram). Conclusions: Vascular connections between the obturator system and the external iliac or inferior epigastric systems were found over the superior pubic ramus with a high incidence. They are prone to damage during the ilioinguinal approach as an anterior approach to the acetabulum and pelvis. Thus, corona mortis located over the superior pubic ramus deserves great attention during the ilioinguinal approach.     

Needle placement and injection posterior to the axillary artery may predict successful infraclavicular brachial plexus block: a report of three cases

PURPOSE: The combined use of ultrasound and nerve stimulation for localization of the brachial plexus during infraclavicular block has not been evaluated. We describe three cases of infraclavicular block where we used ultrasound to place the needle and catheter, observe type of muscle twitch obtained and local anesthetic spread after injection. CLINICAL FEATURES: Injection of local anesthetic after obtaining proximal muscle stimulation was associated with local anesthetic spread between the axillary artery and pectoral muscle. This resulted in block failure (case 1).In case 2, proximal stimulation was associated with anterior spread after a test injection. The needle and subsequently the catheter were repositioned posterior to the axillary artery and distal muscle stimulation obtained. Injection through the catheter resulted in local anesthetic spread posterior to the artery and successful block.In case 3, no distal twitch could be obtained but in light of previous experience the needle and then the catheter were placed posterior to the axillary artery. Posterior local anesthetic spread was observed and successful block ensued despite absence of any muscle stimulation. CONCLUSION: Ultrasound guidance during infraclavicular brachial plexus block enables direct visualization of needle/catheter tip location and confirmation of appropriate local anesthetic spread. Our early experience suggests that spread of injectate posterior to the second part of the axillary artery is associated with successful block.     

Role of local anesthetic spread pattern and electrical stimulation in ultrasound-guided musculocutaneous nerve block

Study ObjectiveTo evaluate local anesthetic spread on the frequency of success of musculocutaneous nerve block, and to determine needle-to-target-nerve distance by ultrasound imaging and electrical stimulation.DesignObservational study.SettingsPrivate hospital.Patients48 ASA physical status I and II adults (16 men and 32 women) scheduled for elective carpal tunnel release or wrist ganglion cyst surgery in an outpatient setting.InterventionsThe musculocutaneous nerve (MCN) was identified by ultrasound. An insulated needle connected to an electrical stimulator in the “off” position was inserted in the biceps side of the probe in the plane of the ultrasound beam. The needle tip was placed in the vicinity of the MCN.MeasurementsLocal anesthetic spread pattern was determined by ultrasound imaging. The lowest effective current intensity was registered. The average depth of the MCN was measured by ultrasound.Main ResultsIn all patients, the local anesthetic solution spread was uneven. In 32% of patients (15/47), motor response was still elicited with electrical stimulation intensity lower or equal to 0.3 mA. In 26% of patients (12/47), motor response disappeared with electrical stimulation intensity higher or equal to 0.6 mA. In 42% of patients (20/47), motor response disappeared at intensities between 0.3 mA and 0.5 mA.ConclusionsA high success rate of MCN anesthesia occurred with non-circumferential spread of local anesthetic solution. Electrical current intensity was not a reliable indicator of needle-to-target-nerve distance.     

Confirmation of Caudal Needle Placement Using Nerve Stimulation

Background: The study was designed to examine a new method of confirming proper caudal needle placement using nerve stimulation.

Methods: Thirty-two pediatric patients were studied. A 22-gauge insulated needle was inserted into the caudal canal via the sacral notch until a "pop" was felt. The needle placement was classified as correct or incorrect depending upon the presence or absence of anal sphincter contraction (S2-S4) to electrical simulation (1 to 10 mA).

Results: Three patients were excluded, two because they inadvertently received neuromuscular blockers and one because the patient's anatomy precluded any attempt at a caudal block. The sensitivity and specificity of the test were both 100% in predicting clinical outcomes of the caudal block. Six patients had a negative stimulation test after the first attempt to place the needle. Four of these went on to receive a second attempt of needle insertion after a subcutaneous bulge or resistance to local anesthetic injection were observed. Following needle reinsertion, positive stimulation tests were elicited. These patients received the local anesthetic injection with ease and had good analgesia postoperatively. No attempt was made to reinsert the needle in the remaining two patients with a negative stimulation test, as they did not show subcutaneous bulge or resistance upon injection. These patients had poor analgesia postoperatively. The positive predictive value of the test was greater than the presence of a "pop" alone (P < 0.05) but not significantly different (P = 0.492) over the presence of "pop" and easy injection.     

A paravenous approach for the saphenous nerve block

BACKGROUND AND OBJECTIVES: This study assesses a paravenous approach for saphenous nerve block at approximately the level of the tibial tuberosity, and compares it with the conventional technique of blind subcutaneous infiltration between the tibial tuberosity and the gastrocnemius muscle. METHODS: In dissections of 5 cadavers, the saphenous nerve was found very close to the saphenous vein bilaterally. Subsequently, in 20 volunteers, a bilateral saphenous nerve block was performed with 5 mL mepivacaine on each side. Randomly assigned, the block was performed by blind subcutaneous injection using a 23-gauge needle of 2.5 cm on one side and by a paravenous subcutaneous approach on the other. RESULTS: The paravenous approach produced a saphenous nerve block in all 20 volunteers whereas the blind subcutaneous approach was successful in only 6 (33%) (P <.05). Seven volunteers had a painless minor hematoma at the paravenous site and 2 had a hematoma at the classical site. CONCLUSION: The saphenous nerve can be blocked effectively by a paravenous approach using only 5 mL of local anesthetic solution. This approach is advantageous because of its easily identifiable landmark.     

Ultrasound-guided obturator nerve block

We reviewed the technique and anatomy for the ultrasound-guided obturator nerve block, especially interadductor approach. Although it is sometimes difficult to observe obturator nerve in the ultrasound image, obturator nerve block is completed observing three muscle layers, adductor longus muscle, adductor blevis muscle and adductor magnus muscle, in the ultrasound image. Local anesthetics are injected between the muscle layers confirming the needle tip and spread of the solution. This technique will reduce incomplete effect or side effects of the obturator nerve block.     

Evolution of ultrasound guided axillary brachial plexus blockade: retrospective analysis of 662 blocks

PURPOSE: Ultrasound (US) is being used increasingly to guide needle placement during axillary brachial plexus blockade (AXB). This retrospective study investigated whether US guidance can increase the success rate, decrease block onset time, and reduce local anesthetic (LA) volume for AXB compared to a traditional (TRAD) approach, namely, peripheral nerve stimulation (PNS) and transarterial (TA) techniques. METHODS: The anesthetic records, operative reports, discharge summaries, and surgical consultation notes of all patients who had undergone AXB for surgical anesthesia at the Toronto Western Hospital, between October 2003 and November 2006 were, retrospectively reviewed for evidence of block success and associated complications. Block success was defined as the achievement of surgical anesthesia without additional LA supplementation. RESULTS: Among the 662 patients, 535 patients underwent AXB using US guidance (US group), and 127 using TRAD techniques (TRAD group), namely, 56 using PNS (PNS subgroup) and 71 using the TA technique (TA subgroup). The block success rate was higher in the US group compared to the TRAD group (91.6% vs 81.9%, P = 0.003). The LA volume used for AXB was less in the US group compared to the TRAD group (39.8 +/- 6.4 mL vs 46.7 +/- 17.1 mL, P < 0.0001). Ultrasound group patients spent less time in the block procedure room than those in the TRAD group (30.6 +/- 14.2 min vs 40.1 +/- 27.3 min, P < 0.0001). When analyzed by subgroup, the US group demonstrated significantly greater success and shorter duration in the block room compared to the PNS subgroup, but not the TA subgroup. Complications (inadvertent intravenous LA injection, and transient neuropathy) were lower in the US group compared to the TRAD group (0.37% vs 3.15%, P = 0.014). CONCLUSIONS: Our results suggest that US-guided AXB may improve block success, reduce the local anesthetic volume used, and shorten the time spent in the block room compared to traditional nerve localization techniques.     

改良喙突入路臂丛神经阻滞的效果观察

目的 观察改良喙突人路臂丛神经阻滞的可行性.方法 60例ASA Ⅰ或Ⅱ级上肢手术患者随机均分为喙突法组(A组)和腋路法组(B组),A组在喙突尖向内下2 cm处绝缘针垂直于皮肤进入,B组取腋动脉上方搏动最强处进针.将神经刺激仪设置为电流1 mA、频率2 Hz.当电流减小到0.3 mA时仍可见到正中、尺、桡神经任一神经支配区肌肉颤搐时,固定刺激针,回吸无血后注入0.5%罗哌卡因 1%利多卡因混合液30 ml.比较两组的人针深度、止血带痛发生率、感觉及运动阻滞的成功率及时间.结果 A组人针深度明显深于B组(P＜0.05).A组止血带痛发生率明显短于B组(P＜0.05).A组中正中、桡、肌皮、腋、臂内侧皮神经感觉完全阻滞的成功率明显高于B组(P＜0.05),桡、肌皮、腋神经感觉达到完全阻滞的时间也明显短于B组(P＜0.01).A组运动完全阻滞的成功率明显高于B组(P＜0.05),达到最大运动阻滞的时间也明显短于B组(P＜0.01).结论 改良喙突人路法臂丛操作简便,阻滞成功率高,阻滞效果好.