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Sivaporn Termpornlert,1 Amorn Vijitpavan,1 Montien Ngodngamthaweesuk,2 Lisa Sangkum,1 Lalisa Saeaeh,1 Benjaporn Pipatpongsa,1 Prangmalee Leurcharusmee,3 Samon Wanishpongpan,3 Shinichi Sakura4 1Department of Anesthesiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 2Department of Cardiovascular Thoracic Surgery, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 3Department of Anesthesiology, Faculty of Medicine Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University, Chiang Mai, Thailand; 4Department of Anesthesiology, University Hospital Shimane University Faculty of Medicine, Izumo, JapanCorrespondence: Sivaporn Termpornlert; Amorn Vijitpavan, Department of Anesthesiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Phaya Thai, Ratchathewi, Bangkok, 10400, Thailand, Tel +66-2-2011513, Fax +66-2-2011569, Email stermpornlert@gmail.com; fluotec@gmail.comPurpose: Thoracic paravertebral block (TPVB) is a recommended regional analgesia during video-assisted thoracoscopic surgery (VATS). However, single-injection TPVB does not last long enough to provide sufficient acute postoperative pain relief. Continuous TPVB through a catheter is technically challenging and often unreliable. Intravenous dexamethasone extends the analgesic duration with some peripheral nerve blocks. However, data on the effect of intravenous dexamethasone on pain relief with TPVB are limited. This study aimed to assess the analgesic efficacy of intravenous dexamethasone in patients who received TPVB for VATS.Patients and Methods: In this multicenter prospective randomized controlled trial, we recruited patients aged between 18 and 80 years with the American Society of Anesthesiologists of physical status class 1– 3 and underwent elective VATS. Patients under general anesthesia randomly received 8 mg of intravenous dexamethasone (group D) or normal saline (group C). Ultrasound-guided TPVB (USG-TPVB) was performed at the T4–T5 and T6-T7 spaces. Multimodal analgesia was achieved via paracetamol, tramadol and intravenous morphine for both study groups. The primary outcome was time for the first analgesic requirement. Postoperative pain in terms of numeric rating score (NRS), total morphine consumption and postoperative nausea and vomiting (PONV) were assessed.Results: After excluding one patient, 59 patients were analyzed. There were no intergroup differences in baseline characteristics. The time to first analgesic requirement was longer in group D (305 [240, 510] minutes) than in group C (270 [180, 300] minutes) (P value = 0.02). The NRS at rest and on movement was lower in group D than in group C at 12 hours but did not differ at other time points. Postoperative morphine consumption was significantly lower in group D than in group C at 6,12,24 and 48 hours. Incidences of PONV were comparable between the groups.Conclusion: Intravenous dexamethasone, used as an adjunct to a single-injection USG-TPVB prolonged analgesic duration, had an opioid-sparing effect and provided better postoperative pain relief after VATS.Keywords: thoracic paravertebral block, analgesic duration, postoperative pain, opioid-sparing effect

Remifentanil is useful in balanced anesthesia; however, there is concern regarding opioid-induced hyperalgesia. The effect of remifentanil on rebound pain, characterized by hyperalgesia after peripheral nerve block has rarely been studied. This study evaluated whether intraoperative remifentanil infusion may increase postoperative analgesic requirement in patients receiving preoperative interscalene brachial plexus block (IBP).Sixty-eight patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly allocated to remifentanil (R) or control (C) group. Preoperative IBP with 0.5% ropivacaine 15 mL was performed in all patients. Intraoperative remifentanil was administered only in the R group. Postoperative pain was controlled using intravenous patient-controlled analgesia (IV-PCA) and rescue analgesics. The primary outcome was the dosage of fentanyl-nefopam IV-PCA infused over 24 h postoperatively. The secondary outcomes included the numeric rating scale (NRS) score recorded at 4-h intervals over 24 h, amount of rescue analgesics and total postoperative analgesics used over 24 h, occurrence of intraoperative hypotension, postoperative nausea and vomiting (PONV) and delirium.The dosage of fentanyl-nefopam IV-PCA was significantly less in C group than R group for postoperative 24 h. Fentanyl 101 [63-158] (median [interquartile range]) µg was used in the C group, while fentanyl 161 [103-285] µg was used in the R group (median difference 64 µg, 95% CI 10-121 µg, P = 0.02). Nefopam 8.1 [5.0-12.6] mg was used in the C group, while nefopam 12.9 [8.2-22.8] mg was used in the R group (median difference 5.1 mg, 95% CI 0.8-9.7 mg, P = 0.02). The total analgesic consumption: the sum of PCA consumption and administered rescue analgesic dose, converted to morphine milligram equivalents, was higher in the R group than C group (median difference 10.9 mg, 95% CI 3.0-19.0 mg, P = 0.01). The average NRS score, the incidence of PONV and delirium, were similar in both groups. The incidence of intraoperative hypotension was higher in R group than C group (47.1% vs. 20.6%, P = 0.005).Remifentanil administration during arthroscopic shoulder surgery in patients undergoing preoperative IBP increased postoperative analgesic consumption.

Background Anterior cruciate ligament (ACL) reconstruction is an invasive surgical procedure for the knee. Quadruple nerve blocks including continuous femoral nerve block and single-injection sciatic, obturator, and lateral femoral cutaneous nerve blocks can provide effective intraoperative anesthesia and analgesia in the early postoperative period. However, severe pain often appears after the effect of single-injection nerve blocks resolves and that is why we conducted two studies. The first study was to determine whether dexamethasone administered along with local anesthetic for sciatic nerve block could prolong the duration of analgesia in patients given quadruple nerve blocks, including continuous femoral nerve block, for ACL reconstruction using a hamstring tendon autograft. The second study was designed to evaluate any difference in effects from dexamethasone administered perineurally versus intravenously. Methods Patients undergoing unilateral arthroscopic ACL reconstruction using a hamstring tendon autograft were enrolled into two studies. The first study was prospectively conducted to see if dexamethasone 4 mg could prolong the duration of analgesia when administered perineurally to the subgluteal sciatic nerve with 0.5% ropivacaine. In the second study, we retrospectively evaluated the effects of intravenous dexamethasone 4 mg as compared with those of perineural dexamethasone to the sciatic nerve block and effects with no dexamethasone. Results In the first study, perineural dexamethasone prolonged the duration of analgesia by 9.5 h (median duration: 22.5 and 13.0 h with and without perineural dexamethasone, respectively, P = 0.011). In the second study, the duration of analgesia was similarly prolonged for intravenous and perineural dexamethasone compared with no dexamethasone. Conclusion Perineural dexamethasone administered along with local anesthetic for single sciatic nerve block prolonged the duration of analgesia of quadruple nerve blocks for ACL reconstruction, however the effects were not different from those of intravenous dexamethasone. Trial registration The protocols of both studies were approved by the Institutional Review Board of Shimane University Hospital, Japan (study number 2821 and 3390 for study 1 and study 2, respectively). Study 1 was registered in University Hospital Medical Information Network Clinical Trials Registry (UMIN000028930). Study 2, which was a retrospective study, was not registered.

Purpose Thoracic paravertebral block (TPVB) is an established analgesic technique for breast surgery although it is technically challenging. Erector spinae plane block (ESPB) requires less technical expertise and may be an alternative to TPVB. However, whether ESPB has similar analgesic effects to TPVB for breast surgery is still inconclusive. Moreover, information on sensory blockade of ESPB is scarce. Accordingly, we conducted this retrospective propensity-matched study to see if ESPB could provide comparable analgesic effects to TPVB in patients undergoing breast surgery. We also compared cutaneous sensory block levels after the two techniques. Patients and methods In this retrospective cohort study, we analyzed data saved in our database and compared the two techniques using a propensity matching method. The data of patients who underwent unilateral breast surgery under general anesthesia with the addition of either TPVB or ESPB were identified. We considered that the analgesic efficacy of ESPB was noninferior to TPVB if both postoperative fentanyl consumption and area under the curve (AUC) for pain scores within 24 h were within 50 µg and 240 mm･h margins, respectively. Cutaneous sensory block levels, additional analgesic requirements, and complications were also compared between the two groups. Results Among 93 patients, 30 patients for each group were matched. Both postoperative fentanyl consumption and AUC for pain scores after ESPB were noninferior to those after TPVB. ESPB did not produce sensory blockade consistently, and the number of dermatomes was smaller after ESPB [1 (0-3)] [median (interquartile range)] than after TPVB [4 (2-5)] (P=0.002). No serious complications related to blocks were observed. Conclusion ESPB and TPVB provided comparable postoperative analgesia for 24 h in patients undergoing breast surgery. Dermatomal sensory blockade was, however, less apparent and narrower after ESPB than after TPVB.

Continuous femoral nerve block (FNB) has been effectively used after total hip arthroplasty (THA). Recently the anterior approach to quadratus lumborum block (QLB) has been shown to produce postoperative pain relief after THA. Continuous QLB would benefit from a catheter insertion site that is farther away from the surgical site compared with continuous FNB. In this randomized controlled study, we compared analgesic effects of the two techniques in patients undergoing THA. Thirty patients undergoing THA were randomly allocated into two groups receiving continuous QLB and FNB. Under ultrasound guidance, QLB and FNB were conducted before general anesthesia using 0.25% levobupivacaine 30 ml and 0.5% levobupivacaine 15 ml, respectively, and a catheter was introduced. Postoperatively, all patients received continuous infusion of 0.125% levobupivacaine at 4 ml/h. Postoperative measurements included visual analog scale (VAS) pain scores at rest and on movement, postoperative analgesic demands, cutaneous sensory blockade and adverse events for 48 h. Six patients were excluded and 24 patients (13 and 11 patients in QLB group and FNB, respectively) were analyzed. VAS scores on movement at 6 h [median (IQR): 67 (41–80) and 38 (22–41) in QLB and FNB groups, respectively, p = 0.008] and 24 h [60 (40–80) and 39 (28–64) in QLB and FNB groups, respectively, p = 0.018] were lower with FNB than with QLB. QLB did not produce consistent cutaneous sensory blockade. Analgesic effects of continuous QLB were inferior to those of continuous FNB in patients undergoing THA under the current study condition.

Background: The posterior transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) were developed for postoperative pain control after lower abdominal surgery. However, there is little data regarding their effects. Their analgesic effects and the distribution of the cutaneous sensory blockade were observed in patients undergoing laparoscopic gynecologic surgery. Methods: After an induction of general anesthesia, patients alternately received bilateral ultrasound-guided QLB type 2 (QLB2) or posterior TAPB using 20 ml of 0.375% levobupivacaine on each side. The measurements included visual analogue pain scores (VAS), cutaneous sensory blockade in each dermatome, demands for postoperative analgesics, and complications for up to 48 h after the block. Our primary endpoint was VAS at 24 h after the block. Results: Forty patients completed the study. The VAS at rest was significantly lower after QLB2 than that after TAPB at 48 h, but not at 24 h. Neither group differed in VAS when coughing at any point in time. Postoperative demands for fentanyl and other analgesics also did not differ for either block. The majority of injections produced a cutaneous sensory blockade in the T11 and T12 dermatomes in both groups. The median number of dermatomes blocked was limited to three dermatomes after either block. No severe complication related to either block was observed. Conclusions: The analgesic effects of QLB2 and posterior TAPB did not differ in patients undergoing laparoscopic gynecologic surgery. The cutaneous sensory blockade produced was limited to three dermatomal levels in the majority of patients. However, these findings need to be confirmed through a larger comparative study.

Background Spinal muscular atrophy (SMA) is a mostly autosomal recessive genetic disease characterized by progressive muscle weakness from anterior horn degeneration. Nusinersen has recently been approved as a disease-modifying drug for SMA that needs to be administered intrathecally. Its injection is often associated with extreme difficulty since patients with SMA have severe vertebral deformity and may be with vertebral instrumentation. Case description A 21-year-old female with type 2 SMA and spinal deformity underwent a series of intrathecal injections of nusinersen. The intrathecal injections have been safely and successfully done by using computed tomography imaging and ultrasonography-assisted technique. Conclusion This the first report in which ultrasound-assisted technique has been used for the injection of nusinersen through a lumbar puncture in patients with severe spinal deformity. Use of preprocedural ultrasound imaging is highly recommended for treatments that repeatedly require intrathecal access.

Continuous interscalene brachial plexus block (CISB) provides analgesia after shoulder surgery. However, even a catheter securely fixed at the insertion site may be susceptible to migration, precluding the block from working consistently. We examined to see if catheter tip migration would occur with no catheter-at-skin change after anterior and posterior approaches to CISB in patients undergoing shoulder surgery, and compared the incidence rate and pain scores between approaches and between catheters with and without tip migration, respectively. Patients were randomly assigned to receive CISB using either anterior or posterior approach. Catheter tip was observed using a cross-sectional view. The rates of catheter tip migration with no catheter-at-skin change at 24 h after the two approaches were calculated and compared, and pain scores were compared between catheters with and without tip migration after each approach. Fifty-four patients were analyzed. Catheter tip migration occurred at 24 h at a similar rate after both approaches (anterior approach 40.7% versus posterior approach 33.3%, p = 0.78). Worst pain score was significantly higher for 24 h in patients whose catheter tip had migrated as compared with those whose catheter had not migrated after anterior (median [IQR] 53 [42–73] versus 18 [0–50], p = 0.003) and posterior approaches (median [IQR] 63 [57–81] versus 29 [3–47], p

BackgroundAlthough neurologic sequela is a recognized complication after interscalene brachial plexus block (ISB), there is a paucity of information on how severe and persistent neuropathy occurs and develops.Case presentationA healthy high school soccer goalkeeper was scheduled for an arthroscopic Bankart repair. After continuous ISB for 2 days, sensation in the C5 and C6 areas and motor function did not return. With symptomatic drug treatment for neuropathic pain and rigorous rehabilitation, recovery of sensory loss and muscle weakness were gradually observed around 1 to 2 months after surgery. He returned to sport 1 year after surgery.ConclusionThis report is the first detailed description of a case who incurred severe and persistent nerve injury after continuous ISB yet recovered nearly fully to return to being an athlete. The present case should also underscore the importance of close observation after surgery in cases where a patient receives continuous ISB.

Quadratus lumborum block (QLB) has recently attracted attention as a part of multimodal analgesia after abdominal surgery. It has been shown that programmed intermittent boluses of local anesthetic can produce better analgesia and wider sensory blockade compared with continuous basal infusion with some peripheral nerve blocks. The present study was conducted to see if this theory holds true for QLB in patients undergoing laparoscopic colorectal surgery. Fifty patients undergoing laparoscopic colorectal surgery were divided into 2 groups to receive continuous basal infusion (group C) or programmed intermittent boluses (group PIB) of local anesthetic. After surgery, patients received the posterior approach to QLB and a catheter was introduced bilaterally. Patients in group C received a continuous infusion of 0.15% levobupivacaine at 3 ml/h, and those in group PIB received a bolus of 12 ml every 4 h. All patients received intravenous patient-controlled analgesia using fentanyl. Measurements were taken for cumulative fentanyl consumption, pain scores, cutaneous sensory blockade, analgesic requirements, and adverse events for 46 h. The primary outcome of cumulative fentanyl consumption at 22 h showed no significant difference between the groups [group C: 11.9 (11.2–15.5) µg/kg (median (interquartile range)) and group PIB: 12.3 (11.6–15.3), p = 0.473]. Pain scores, demands for rescue analgesics, and spread of cutaneous sensory blockade were similar for the two groups. Programmed intermittent boluses of local anesthetic for continuous QLB did not produce better analgesia or wider sensory blockade compared with continuous basal infusion in patients undergoing laparoscopic colorectal surgery.

To the Editor We wish to thank Wardhan et al [1][1] for their interest in our study.[2][2] Despite the popularity of continuous thoracic paravertebral block (TPVB), there remains a paucity of information on catheter-tip position and distribution of injectate through the catheter. We believe that

Background and aims Thoracic paravertebral block (PVB) is an established technique for perioperative pain management for breast surgery. However, since this block is technically challenging, it has not been widely used. Recently introduced erector spinae plane block (ESPB) requires less technical expertise and may be an alternative to PVB. However, the two blocks have not been fully compared. the present study retrospectively analyzed data saved in our registry to compare the two blocks in patients undergoing breast surgery. Methods After IRB approval, we extracted data for breast surgery patients receiving either PVB or ESPB under ultrasound guidance from June 2018 to March 2019. We compared intra and postoperative data. the primary outcome was visual analogue pain scores (VAS) at rest at 12 h after block. the secondary outcome included scanning and performing time for block, dermatomal sensory blockade, and postoperative fentanyl consumption for 24 h. Results 26 PVB and 25 ESPB patients were evaluated. Patient demographics were comparable. VAS at rest at 12 h was similar [PVB 13 (0–30) vs ESPB 25 (12–40), P=0.069] [median (IQR)]. However, VAS at rest at 6 h was lower after PVB [10 (0–24)] than after ESPB [25 (18–40)] (P Conclusions The two blocks had different characteristics but were similar in pain scores at 12 h after block.

Background and aims Continuous femoral nerve block (cFNB) has been effectively used after total hip arthroplasty (THA). Recently, transmuscular quadratus lumborum block (tQLB) has been introduced to produce postoperative pain relief after THA. Continuous tQLB (ctQLB) would benefit from the catheter insertion site that is farther away from the surgical site compared with cFNB. No studies have compared analgesic effects of ctQLB and cFNB. In this randomized controlled study, we compared these techniques in patients undergoing THA. Methods With IRB approval and informed consent, we enrolled 30 patients undergoing unilateral THA, who were randomly divided into two groups receiving either ctQLB or cFNB. Under ultrasound guidance, QLB and FNB were conducted before general anesthesia using 0.25% levobupivacaine 30 ml and 0.5% levobupivacaine 15 ml, respectively, and a catheter was introduced. All patients received continuous infusion of 0.125% levobupivacaine 4 ml/h postoperatively. Postoperative measurements included visual analog scale (VAS), postoperative use of analgesic, cutaneous sensory blockade, motor strength of the thigh, and adverse events for 48 hours. Results Of the 30 patients, 6 were excluded and 24 (13 and 11 patients in groups QLB and FNB, respectively) were analyzed. VAS on movement at 6 and 24 hours was lower with cFNB than with ctQLB (figure 1). VAS at rest, demands for PCA and other analgesics, and motor strength of the thigh were similar between the two groups. QLB did not produce consistent cutaneous sensory blockade. No severe complication was observed. Conclusions Analgesic effects of ctQLB were inferior to those of cFNB in patients undergoing THA.

Managing pain during movement after hip fracture surgery is important for achieving earlier hip mobilisation and for preventing postoperative complications. In the present study, we tested the hypothesis that the fascia iliaca compartment block (FICB) would improve postoperative pain on movement compared with intravenous acetaminophen.In this prospective, randomised, controlled, parallel trial, patients were assigned to either the intravenous acetaminophen or the ultrasound-guided FICB group. Visual analog scale (VAS) pain scores were evaluated at 6, 9, 12, 18, 24 h, 2 days, and 7 days postoperatively. The primary outcome was VAS scores on movement at 24 h after surgery. The secondary outcomes were VAS scores on movement at the other time points, VAS scores at rest, the total number of rescue analgesics required and incidence of delirium during the first 24 h postoperatively, potential drug or block-related complications, and the time to first standing.VAS scores on movement at 24 h after surgery were significantly lower in the FICB group than in the intravenous acetaminophen group [median (the 25th to 75th percentiles), 20 (10-30) vs 40 (30-53); P 0.01]. The VAS scores on movement at any other time point and the scores at rest at 12 h after surgery were also significantly lower in the FICB group than in the intravenous acetaminophen group. The two groups did not differ in terms of the total number of rescue analgesics required or the incidence of delirium during the first 24 h postoperatively; complications; or the time to first standing.FICB improved postoperative pain on movement compared with intravenous acetaminophen without increasing the complication rate. However, the total number of rescue analgesics required and the time to first standing were not significantly different between the two groups.

With recent changes in surgical procedures and perioperative management, there has been a growing interest in peripheral nerve blocks of the trunk in patients undergoing thoracic and breast surgery. Tho- racic truncal blocks include paravertebral, pecs, intercostal, and retrolaminar blocks. Previous studies have demonstrated that paravertebral block provides similar analgesic effects and better hemodynamic stability compared with epidural analgesia. In addition, the results of several studies suggest that paravertebral block may improve long-term outcomes such as pre- vention of chronic pain and decrease in recurrence or metastasis after breast cancer surgery. Pecs blocks are novel ultrasound-guided blocks intended to provide analgesia of the anterior chest wall while avoiding seri- ous complications associated with epidural anesthesia and paravertebral block. The novel ultrasound-guided techniques for intercostal nerve blocks have also been reported. Although some case series support that these pecs and intercostal nerve blocks appear to be safe and effective, prospective randomized studies to confirm their clinical usefulness are lacking. Whether to con- duct these thoracic truncal blocks or not will become a standard clinical practice for thoracic and breast sur- gery is yet to be determined.

BACKGROUND: It is believed that local anesthetic injected to obtain circumferential spread around nerves produces a more rapid onset and successful blockade after some ultrasound-guided peripheral nerve blocks. However, evidence demonstrating this point is limited only to the popliteal sciatic nerve block, which is relatively easy to perform by via a high-frequency linear transducer. In the present study, we tested the hypothesis that multiple injections of local anesthetic to make circumferential spread would improve the rate of sensory and motor blocks compared with a single-injection technique for ultrasound-guided subgluteal sciatic nerve block, which is considered a relatively difficult block conducted with a low-frequency, curved-array transducer. METHODS: Ninety patients undergoing knee surgery were divided randomly into 2 groups to receive the ultrasound-guided subgluteal approach to sciatic nerve block with 20 mL of 1.5% mepivacaine with epinephrine. For group M (the multiple-injection technique), the local anesthetic was injected to create circumferential spread around the sciatic nerve without limitation on the number of needle passes. For group S (the single-injection technique), the number of needle passes was limited to 1, and the local anesthetic was injected to create spread along the dorsal surface of the sciatic nerve, during which no adjustment of the needle tip was made. Sensory and motor blockade were assessed in double-blind fashion for 30 minutes after completion of the block. The primary outcome was sensory blockade of all sciatic components tested, including tibial, superficial peroneal, and sural nerves at 30 minutes after injection. RESULTS: Data from 86 patients (43 in each group) were analyzed. Block execution took more time for group M than group S. The proportion of patients with complete sensory blockade of all sciatic components at 30 minutes after injection was significantly larger for group M than group S (41.9% vs 16.3%, P = 0.018). Complete motor blockade of foot and toes extension also was observed more frequently in group M than in group S (67.4% vs 34.9%, P = 0.005 and 51.2% vs 25.6%, P = 0.027, respectively). CONCLUSIONS: When ultrasound-guided subgluteal sciatic nerve block is conducted, multiple injections of local anesthetic to make a circumferential spread around the sciatic nerve improve the rate of sensory and motor blocks compared with a single injection.

Background The present study was conducted to determine the incidence of unintentional intraneural injection during ultrasound-guided subgluteal sciatic nerve block using a low-frequency transducer. We also observed the effects of intraneural injection using ropivacaine and mepivacaine. Methods Enrolled in the study were 325 patients undergoing arthroscopic knee surgery, who each received a subgluteal sciatic nerve block under ultrasound guidance using 1.5% mepivacaine with 1:400,000 epinephrine or 0.5% ropivacaine. A block needle was inserted in-plane with the ultrasound transducer (5-2 MHz curved array) and advanced slowly under real-time ultrasound guidance until it was positioned immediately adjacent to the nerve. Twenty milliliters of either anesthetic was then injected to produce a circumferential spread. An ultrasound video was recorded and used to examine whether the local anesthetic was injected intraneurally. Sensory and motor blockade was evaluated for 30 mins after completion of the block. Duration of the block and any neurologic complications were also examined. Results Intraneural injection was detected in 46 patients (16.3%; 95% confidence interval, 12.3%–20.3%). Onset of sensory and motor blockade was significantly faster in patients with intraneural injection than those without either mepivacaine or ropivacaine. Duration of sensory blockade was similar between patients with and without intraneural injection. No patient developed postoperative neurologic complications. Conclusions Unintentional intraneural injection occurred at an incidence rate of 16.3% for the ultrasound-guided subgluteal approach to the sciatic nerve. Intraneural injection of mepivacaine or ropivacaine hastened the onset of blockade but did not affect block duration, and it did not result in clinical neural injury in our small sample of patients.

硬膜外麻酔においては局所麻酔薬の濃度, 容量, および総投与量が麻酔域に影響を与える. しかし, 冷覚テストやピンプリックテストなどといった従来の判定法で得られた麻酔域は外科的な侵襲に耐えうる麻酔域を正確に示してはおらず, これを判定するためには神経遮断域の広がりのみではなく, 麻酔域における神経遮断の強度を認識する必要がある. 神経遮断の強度は, 等量の局所麻酔薬を使用する場合において, より高濃度のものを使用する方が有効に侵害刺激を遮断することができる. 硬膜外麻酔域判定が困難となる全身麻酔併用症例においても, より高濃度の局所麻酔薬を使用することにより有効に侵害刺激を遮断でき, 質の高い麻酔管理が行えると考えられる.

Planning safe perioperative management for patients undergoing continuous ambulatory peritoneal dialysis (CAPD) catheter surgery (insertion and extraction of the catheter) is often difficult because many of these patients not only have renal insufficiency but also have co-existing disorders, such as heart diseases. As increased indications for perioperative anticoagulation therapy have limited the choice of anesthesia, selecting an appropriate anesthetic method, particularly for patients with poor systemic conditions, is becoming more challenging. We report seven cases of CAPD catheter surgery successfully managed by monitored anesthesia care using subcostal transversus abdominis plane (TAP) block with additional local anesthetic infiltration and analgesics. Despite co-existing cardiac disease and/or coagulation disorders, all patients were safely managed without any other major anesthetic methods. Subcostal TAP block is a useful anesthetic option for CAPD catheter surgery, particularly for patients with poor systemic conditions and/or in whom neuraxial blocks are contraindicated.

Although epidural lidocaine administered as a bolus has been shown to cause little neurotoxicity, local anesthetics are often administered repetitively or continuously into the epidural space, and in high doses may induce neurologic injury. We investigated whether epidural lidocaine is neurotoxic when a large dose is continuously administered in rats, and whether the functional impairment and histologic damage is dose dependent. In Experiment 1, 13 rats received a 120-min epidural infusion (at 5 microL/min) of saline or 2% lidocaine. Four days after infusion, rats given 2% lidocaine developed significantly more prolonged tail-flick latencies and showed more apparent morphologic damage than those given saline. In Experiment 2, 41 rats were randomly divided into 5 groups to receive an epidural infusion of saline for 120 min or 5% lidocaine for 15, 30, 60, or 120 min at a rate of 5 muL/min. Rats given 5% lidocaine for 120 min developed a significant increase in tail-flick latency. Paw pressure thresholds did not change in any group. Nerve injury scores for rats given 5% lidocaine for 30, 60, and 120 min were significantly higher than those for rats given saline. Significant difference in damage in nerve roots was also observed among rats given the anesthetic for different durations of time; nerve injury scores with 120-min infusion were higher than with 15- and 30-min infusions, and injury with 60-min infusion was greater than with 15-min infusion. In conclusion, these results suggest that epidural lidocaine causes dose-dependent neurotoxicity after continuous infusion in rats.

Background: We performed this study to evaluate peripheral nerve function in patients with herpes zoster (HZ) using current perception threshold (CPT) and to compare results between patients who developed post-herpetic neuralgia (PHN) and those who did not. Methods: With Institutional Review Board (IRB) approval and informed consent, 27 patients with HZ were enrolled in the study. At the first visit, all patients were examined clinically and neurophysiologically. CPTs were determined at stimulus frequencies of 2000, 250, and 5 Hz in the affected region and in the contralateral site. Patients were re-examined 6 months after the onset of their symptoms. Patients who still had pain were defined as PHN patients and the others as non-PHN patients. Results: CPT values in affected areas were significantly higher than those in unaffected areas. Thirteen patients were included in the PHN group, and 14 patients in the non-PHN group. Visual analogue scale (VAS) values at the first visit were significantly h...

Study Objective To compare the effects of 0.2% epidural ropivacaine and those of 1% epidural ropivacaine on predicted propofol concentrations and bispectral index scores (BISs) at three clinical end points. Design Randomized double-blind study. Setting University hospital. Patients Thirty-five (35) ASA physical status I and II patients scheduled for elective surgery of the lower abdomen. Interventions Patients were randomly divided into 2 groups to receive epidurally 8 mL of 0.2% or 1% ropivacaine followed by the same solution at a rate of 6 mL/h. Measurements Twenty minutes after starting ropivacaine, a target-controlled infusion of propofol was started to provide a predicted blood concentration of 3 μ g/mL; it increased by 0.5 μ g/mL every 60 seconds until all 3 clinical end points were reached, as follows: P1, when patients lost consciousness; P2, when patients failed to show pupillary dilation and skin vasomotor reflex to transcutaneous electric stimulation applied to the upper level of loss of cold sensation; and P3, when patients failed to show pupillary dilation and skin vasomotor reflex to transcutaneous electric stimulation applied to C5. Main Results The effective concentration 50 values for both predicted blood and effect-site propofol concentrations were significantly larger in the 0.2% group than in the 1% group at all end points. The BIS at every end point was significantly smaller in the 0.2% group than in the 1% group. Conclusions During combined epidural-propofol anesthesia, unconsciousness and lack of response to noxious stimulation occurred at lower predicted concentrations with 1% epidural ropivacaine than with 0.2% epidural ropivacaine. The results also suggest that the BIS may not be a good indicator when propofol anesthesia is combined with epidural anesthesia.

Background The current study investigated whether racemic bupivacaine and its S(-)- and R(+)-enantiomers, levobupivacaine and dextrobupivacaine, differ in somatic and visceral antinociception and neurotoxicity when administered intrathecally in rats. Methods In experiment 1, rats intrathecally received 15 microl saline or 0.125, 0.25, 0.5, or 1% bupivacaine, levobupivacaine, or dextrobupivacaine. The tail-flick and colorectal distension tests were performed to assess somatic and visceral antinociceptive effects, respectively, for 180 min after injection. In experiment 2, rats given 0.25% anesthetic solutions were evaluated with colorectal distension-induced response in blood pressure and heart rate. In experiment 3, four groups of rats received a 1-h infusion of saline or 2.5% bupivacaine, levobupivacaine, or dextrobupivacaine. Additional rats received either 1.25% bupivacaine or levobupivacaine for 1 h. Four days after infusion, animals were assessed for persistent sensory impairment using the tail-flick test. Spinal cords and nerve roots were obtained for histologic analysis. Results In experiment 1, the three drugs produced similar time course effects and dose-effect relations in tail-flick latency. Colorectal distension thresholds and motor paralysis were slightly lower and less apparent, respectively, at some concentrations in rats given levobupivacaine than in those given the other agents. In experiment 2, colorectal distension-induced response in heart rate was less depressed in rats given levobupivacaine than in those given the other anesthetics. In experiment 3, three groups of rats given 2.5% anesthetic solutions developed similar significant increases in tail-flick latency and incurred similar morphologic damage. Two groups of rats receiving 1.25% anesthetic solutions were similar in functional impairment and nerve injury scores. Conclusions The results suggest that, when administered intrathecally in rats, bupivacaine and its R(+)- and S(-)-enantiomers are similar for somatic antinociception and neurotoxicity but slightly different in visceral antinociception and motor paralysis, in which levobupivacaine is less potent than the others.

頸部帯状疱疹患者の発作痛に対してカルバマゼピンを投与したところ, 急激かつ著明な血小板減少をきたした症例を経験した. 症例は72歳, 男性. 頸部帯状疱疹に対し神経ブロックや抗うつ薬, 非ステロイド性抗炎症薬 (NSAIDs) などの内服療法を開始したが疼痛は軽減せず, カルバマゼピン200～400mg・day-1の内服を開始した. 投与16日目に血小板数が1.3万・μl -1と減少し, 出血傾向も認めたためカルバマゼピンの内服を中止した. 中止後6日目には血小板数は25.4万・μl -1と回復し, 以後著変は認めなかった.

UNLABELLED To examine whether the gamma-aminobutyric acid (GABA) receptor agonists and L-type voltage-dependent calcium channel blockers potentiate each other on the visceral antinociceptive effects at the spinal cord, we assessed visceral nociception with colorectal distension (CD) test in rats with an intrathecal catheter. The measurements were performed after intrathecal administration of a GABA agonist (muscimol or baclofen), a calcium channel blocker (diltiazem), or the combination of the two. CD threshold did not change after muscimol 0.1 microg, baclofen 0.01 microg, or diltiazem 100 microg, but increased slightly after muscimol 1 microg and baclofen 0.1 microg. When muscimol 0.1 microg or 1 microg was administered with diltiazem, the increase in CD threshold was significantly larger than muscimol alone (at 5 min, 26.2% versus 0.6% MPE (maximum possible effect) or 84.5% versus 19.5%MPE, respectively; P < 0.01). The CD threshold after the combination of baclofen 0.1 microg and diltiazem also showed a significantly larger increase than that seen after baclofen alone (at 5 min, 48.0% versus 14.3% MPE; P < 0.01). Motor paralysis observed with muscimol 1 microg did not increase when muscimol was coadministered with diltiazem. In conclusion, intrathecal diltiazem in combination with a GABA agonist, muscimol or baclofen, potentiated the GABA agonists-induced visceral antinociception without increasing motor paralysis. IMPLICATIONS Intrathecal administration of diltiazem in combination with a gamma-aminobutyric acid (GABA) agonist, muscimol or baclofen, potentiated the GABA agonists-induced visceral antinociception but did not affect motor paralysis. The present results indicate that the coadministration of the two types of drugs may be clinically useful.

Background Although there is a considerable difference in the number of clinical reports of neurologic injury between spinal anesthesia and other regional techniques, there are no animal data concerning a difference in the local anesthetic neurotoxicity between intrathecal and epidural administration. In the current study, the functional and morphologic effects of lidocaine administered intrathecally and epidurally were compared in rats. Methods Male rats were implanted with an intrathecal or epidural catheter through L4-L5 vertebra in the caudal direction. In experiment 1, to determine relative anesthetic potency, 16 rats received repetitive injections of 2.5% lidocaine into intrathecal or epidural space in different volumes and were examined for tail flick test for 90 min. In experiment 2, to ascertain whether the relative potency obtained in experiment 1 would apply to other concentrations of lidocaine, additional rats received saline, 1%, 2.5%, or 5% lidocaine in a volume of 20 or 100 microl through the intrathecal or epidural catheter, respectively. In experiment 3, additional rats that received saline, 2.5% lidocaine, or 10% lidocaine in a volume of 20 or 100 microl through the intrathecal or epidural catheter, respectively, were examined for persistent functional impairment and morphologic damage. Results In experiment 1, the two techniques produced parallel dose-effect curves that significantly differed from each other. The potency ratio calculated was approximately 4.72 (3.65-6.07):1 for intrathecal:epidural lidocaine. In experiment 2, every lidocaine solution produced a similar increase in tail flick latency for the two techniques. In experiment 3, five of eight rats given 10% intrathecal lidocaine incurred functional impairment 4 days after injection, whereas no rats in the other groups did. Significantly more morphologic damage was observed in rats given 10% intrathecal lidocaine than in those given 10% epidural lidocaine. Conclusions Persistent functional impairment occurred only after intrathecal lidocaine. Histologic damage in the nerve roots and the spinal cord was less severe after epidural lidocaine than after intrathecal lidocaine. The current results substantiate the clinical impression that neurologic complications are less frequent after epidural anesthesia than after spinal anesthesia.

Perioperative hypothermia results largely from core-to-peripheral heat redistribution. Droperidol, which is often used for premedication, promotes vasodilation, and thus may affect redistribution of heat. Accordingly, we tested the hypothesis that preanesthetic droperidol would affect perioperative hypothermia.Twenty-three ASA physical status I patients scheduled for arthroscopic ligament reconstruction were randomly assigned to two groups to receive no premedication or im droperidol 0.1 mg x kg(-1) 30 min before anesthesia. Anesthesia was induced and maintained with propofol and fentanyl. We monitored core (tympanic) and peripheral (palm) temperatures, and skin (fingertip) blood flow for two hours after the induction of anesthesia during surgery.Before the induction of anesthesia, patients given droperidol were more deeply sedated than those given no premedication. Core temperature, which was similar in both groups before induction, decreased significantly more in the control than in the droperidol patients (0.75 +/- 0.34 degrees C and 0.37 +/- 0.20 degrees C, respectively, at 75 min after induction; P0.01). Preinduction peripheral temperature and skin blood flow were lower in the control group than in the droperidol group, but the two variables became similar in both groups after induction.The results of the present study confirm our hypothesis that premedication with droperidol affects perioperative hypothermia. Droperidol may prevent core-to-peripheral heat redistribution after the induction of anesthesia.

UNLABELLED To examine whether adolescents and adults might develop different anesthetic distribution and hemodynamic consequences after spinal injection of 0.5% tetracaine in 7.5% or 0.75% glucose, we studied 100 ASA I or II patients who were scheduled for elective surgery to the lower limb and fulfilled the following criteria: age between 13 and 16 yr (Adolescent group, n = 40) or between 25 and 74 yr (Adult group, n = 60); height between 155 and 180 cm; and body mass index between 18 and 32 kg/m(2). Patients in each group were then randomly divided into two equal subgroups to receive spinal anesthesia with 0.5% tetracaine in either 7.5% or 0.75% glucose with 0.125% phenylephrine at the L3-4 interspace. With patients in the supine horizontal position, neural block was assessed by cold, pinprick, and touch sensation and a modified Bromage scale after the injection of the study drug. The 7.5% glucose solution produced a significantly higher and faster spread of blockade in adolescents than in adults. In contrast, there were no differences in the levels of three sensory modalities between the two age groups after the 0.75% glucose solution, which produced a lower spread of blockade than the 7.5% glucose solution in either age group. Adolescents given the 0.75% glucose solution developed a smaller maximum decrease in systolic pressure than those given the heavier solution. We conclude that adolescents may develop an extensive level of blockade more easily and quickly than adults after intrathecal hyperbaric tetracaine, but that the difference may be reduced by using a less heavy solution. IMPLICATIONS The influence of age on the characteristics of spinal anesthesia is still controversial. Our results show that adolescents develop blockade more extensively and quickly than adults after spinal anesthesia with 0.5%tetracaine in 7.5% glucose but not after the 0.75% glucose solution.