Nerve Block Anesthesia Research Articles

Transient Femoral Nerve Palsy Following Ilioinguinal Nerve Block for Inguinal Hernioplasty.

Background:Elective inguinal hernia repair in young fit patients is preferably done under ilioinguinal nerve block anesthesia in the ambulatory setting to improve throughput, save cost, and increase patient satisfaction. A rare complication of ilioinguinal nerve block is transient femoral nerve palsy (TFNP).Objectives:The aim of this study is to examine the incidence of TFNP among adults undergoing ambulatory inguinal hernia repair under ilioinguinal nerve block.Patients and Methods:Patients 18 years and older in the American Society of Anesthetists classes I and II who underwent ambulatory inguinal hernia repair over a 3-year period under ilioinguinal nerve block only were assessed for evidence of TFNP. All patients had power on the ipsilateral limb checked 30 min before and 1 h after the procedure. TFNP was considered present if there was sensory loss over the anterior aspect of the thigh, weakness of extension at the knee joint, or reduction in power of the ipsilateral limb.Results:One hundred and twelve patients were involved in the study; 90 (80.3%) males and 22 (19.6%) females with the mean age of 45.7 years. All had normal power (Grade 5) in the ipsilateral limb before instituting the nerve block. Postoperatively, 3 (2.6%) patients had grade 4 and recovered normal power over a 2–6-h period and were subsequently discharged.Conclusion:TFNP is a rare complication of ilioinguinal nerve block which delays patient discharge postambulatory hernioplasty.

Perioperative Outcomes after Regional Versus General Anesthesia for Above the Knee Amputations

Nontraumatic lower extremity amputation (LEA) remains a common procedure among patients who frequently have significant comorbidities. Patients undergoing above knee amputation (AKA) have the highest rates of mortality in this cohort, yet there is little evidence to support selection between peripheral nerve block or neuraxial regional anesthesia (RA) versus general anesthesia (GA) techniques. The objective of this study was to determine whether RA (neuraxial or peripheral nerve block) techniques were associated with more favorable outcomes versus general anesthesia among patients undergoing AKA. This is a retrospective cohort study using propensity-matched groups. Patients undergoing AKA were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data set and grouped according to anesthetic type as either RA or GA. Patients undergoing AKA with RA were propensity matched to similar patients who had GA. Primary outcome was 30-day mortality. Secondary outcomes were numerous and included cardiac, pulmonary, infectious, and bleeding complications, as well as length of stay. Among a subset of patients for whom readmission data were available, rate of readmission was compared as a secondary outcome. Nine thousand nine hundred ninety-nine patients were identified in the ACS-NSQIP database. One thousand three hundred twelve received a regional anesthetic, and the remainder had a general anesthetic. Factors significantly associated with GA included younger age (70 vs. 75years; P<0.001), higher body mass index (26.5 vs. 25.4; P<0.001), and ethnically white (62.4% vs. 57%; P<0.001). Before matching, patients receiving RA were less likely to be smokers (22% vs. 29%; P<0.001), have a bleeding disorder (15% vs 30%; P<0.001), or have a diagnosis of sepsis (26% vs 34%; P<0.001). Propensity score matching produced a cohort composed of 1,916 patients equally divided between RA and GA. We found no difference with respect to the primary end point of 30-day mortality (11.7% vs 11.7%; odds ratio [OR] 1.01; P=0.943) nor was there any difference with respect to secondary outcomes. Among patients for whom readmission data were available, there was no statistically significant difference between rates of readmission between the groups (15.6% for RA vs. 12.7% for GA; OR 1.26, confidence interval 0.87-1.828, P=0.221). The present investigation did not detect any difference between regional and general anesthetic with respect to morbidity or mortality among patients undergoing AKA. This data set did not allow us to address other relevant markers including pain control or phantom limb syndrome.

Early Experience with Bilateral Continuous Femoral Nerve Block and Single-Injection Spinal Anesthesia for Bilateral Total Knee Arthroplasty: A Case Series.

Total knee arthroplasty (TKA) is a commonly performed surgery in the United States, with demand for unilateral and simultaneous bilateral TKAs (BTKAs) expected to increase significantly over the coming decades. This study reports the authors' early experience in a consecutive series of simultaneous BTKAs performed under regional anesthesia and mild sedation. In this retrospective case series, the authors examined all simultaneous BTKAs performed over two years by a single surgeon. Only patients receiving bilateral continuous femoral nerve blockade (CFNB) and single-injection sciatic nerve blockade in combination with single-injection subarachnoid block were included in the study. Of the 32 patients who underwent BTKAs during this period, 25 met the inclusion criteria. The patient's anesthesia records, physician notes, nursing notes, pharmacy records, and physical therapy records were then reviewed systematically to create a database of information. Only one of 25 patients required conversion to general anesthesia during surgery. There were no major perioperative complications. The average Defense and Veterans Pain Rating Scale score immediately postoperation was 0.6/10, and the average daily score remained below 3.5/10 throughout the hospital stay. The use of bilateral CFNB did not prevent patients from ambulating during physiotherapy. This early retrospective case series suggests that it is feasible to effectively manage the postoperative pain associated with BTKA with staged bilateral CFNB and single-injection sciatic nerve blockage in combination with single-injection subarachnoid block as the sole anesthetic technique without negatively influencing early ambulation.

Evaluation of intravenous regional anaesthesia and four-point nerve block efficacy in the distal hind limb of dairy cows

BackgroundIntravenous regional anaesthesia (IVRA) and hindfoot four-point nerve block anaesthesia (NBA) are recommended for local anaesthesia (LA) in the distal limb of dairy cows. Two studies were conducted to compare the efficacy, time until onset and stress responses to IVRA and NBA in dairy cows. In the first cross-over designed study, eight healthy unsedated German Holstein cows, restrained in lateral recumbency (LR) on a surgical tipping table, were treated with IVRA and NBA using procaine 2% as a local anaesthetic. Distal limb desensitization was tested by electrical (e-), mechanical (m-) and thermal (t-) nociceptive stimulation 10 min before and 15 and 30 min after LA. Hormonal-metabolic (blood concentrations of cortisol, lactate, non-esterified fatty acids, and glucose) and cardio-respiratory (heart and respiratory rate, mean arterial blood pressure) stress responses to treatment were assessed at predetermined intervals. In the second study, six healthy, unsedated German Holstein cows in LR were treated (crossover design) with IVRA and NBA. Short-interval e-stimulation was measured by the time until complete distal limb desensitization.ResultsIn the first study, four of eight cows responded to e-stimulation 15 min after IVRA, while none of the cows treated with NBA responded until the safety cut-off level was reached. E-stimulation revealed complete desensitization of the distal limb 30 min after LA in all cows. Half of the cows did not respond to m- and t-stimulation before LA, so no further evaluation was performed. Stress reactions to IVRA and NBA treatment were similar, but differences may have been masked by stress response to LR restraint. In the second study, complete desensitization was achieved 12.5 min after NBA, while one of the six cows still responded to e-stimulation 20 min after IVRA.ConclusionHindfoot nerve block anaesthesia and intravenous regional anaesthesia induced complete desensitization of the distal hind limb in dairy cows. However, the anaesthesia onset after NBA was significantly faster than that of IVRA, which may be clinically relevant in the field, particularly when distal limb anaesthesia is required for major claw surgeries under time constraints.

Persistent Genital Arousal Disorder: Current Conceptualizations and Etiologic Mechanisms

Persistent genital arousal disorder (PGAD), characterized in 2001, persists as a distressing malady that is not well appreciated, understood, or treated by healthcare providers. This review describes the characteristics of PGAD, hypotheses regarding its etiology, therapies, and recent findings that provide evidence of PGAD as a genital sensory neuropathy. PGAD can result from (a) Tarlov cysts, which contain aberrant sensory nerve fibers and form on the genital sensory nerves where they abrade on the entrance to the sacrum, and/or (b) herniated intervertebral disc-produced irritation of the roots of those genital sensory nerves as they course through the cauda equina within the spinal canal. Local genital anesthesia or peripheral nerve block often fails to alleviate PGAD symptoms. In that case, the possibility that genital sensory nerve root irritation (i.e., radiculopathy) “upstream” at the entrance to, or within, the spinal canal should be suspected and assessed, optimally by lumbo-sacral-oriented MRI. Imaging can reveal the presence of Tarlov cysts and/or herniated intervertebral disc impingement on the cauda equina, which could provoke PGAD symptoms in women and men and may be treatable. Chronic irritative radiculopathy could eventually affect nerve conduction deleteriously and thereby attenuate genital afferent and/or efferent activity, leading to genital paresthesias, anorgasmia, or anejaculation.

Extraction of mandibular premolars and molars: comparison between local infiltration via pressure syringe and inferior alveolar nerve block anesthesia

The purpose of this study was to evaluate the anesthetic efficiency of local infiltration anesthesia administered with a pressure syringe (P-INF) via a special technique versus direct block anesthesia of the inferior alveolar nerve (IANB) for tooth extraction in the posterior mandible. In a prospective randomized study, 101 teeth in 101 patients were extracted in the posterior mandible under local anesthesia whereby two different administration techniques were used (P-INF n=48; IANB n=53). Primary objectives were comparisons of anesthetic success rate (yes/no) and efficacy (full/sufficient vs. insufficient). Secondary objectives were patients' pain perception during treatment, pain of injection (numerical rating scale), need for second injections (always IANB), time until onset of anesthetic action (min), and duration of local numbness (min). IANB was successful in all cases, whereas initial P-INF achieved 35% of success only. Furthermore, IANB reached significant higher values of anesthetic efficacy compared to P-INF (P<0.001). Concerning pain of injection, patients rated IANB to be more painful (P=0.039). Second injections were significantly more often necessary for P-INF (P=0.006) whereas duration until onset of action as well as the duration of local numbness were found to be equal. For anesthetic efficacy as well as anesthetic success, block anesthesia of the inferior alveolar nerve (IANB) turned out to be more proficient to local infiltration via special delivering system with a special technique. Infiltration, even when performed with 4% articaine and a pressure syringe system, is not a suitable method of anesthesia in the posterior mandible.

Single-Shot Femoral Nerve Block Does Not Cause Long-Term Strength and Functional Deficits Following Anterior Cruciate Ligament Reconstruction

To determine if patients treated with a single-shot femoral nerve block have strength and functional deficits at 9-month follow-up. Forty-three patients who underwent primary anterior cruciate ligament reconstructions were randomized to receive either a preoperative single-shot femoral nerve block or local infiltration anesthesia for primary pain control. All patients underwent a standardized comprehensive rehabilitation program postoperatively. Isokinetic strength and function was tested using a Biodex machine at 9months or more postoperatively comparing the operative and nonoperative extremity. No significant difference in strength was found at an average of 10.6months postoperatively (range, 9-15months) between the femoral nerve block and control groups. In comparing strength deficits, we found no difference in slow isokinetic extension strength (22.4% vs 27.8%, P= .51), fast isokinetic extension strength (18.5% vs 12.5%, P= .41), slow isokinetic flexion strength (11.0% vs 15.1%, P= .55), and fast isokinetic flexion strength (8.2% vs 4.9%, P= .56) in the femoral nerve block versus control groups, respectively. In terms of functional outcomes, there also was no difference in deficits for single-leg hop distance (P= .12), timed single-leg hop (P= .74), and single-leg triple hop distance (P= .94). Maximal strength noted to be within 15% of the contralateral limb was achieved in 40% of patients and maximal function in 63% of patients at an average of 10.6months postoperatively. A 13% complication rate was found in patients who received a femoral nerve block (1 with prolonged quadriceps inhibition and 2 with prolonged sensory disturbances). Our study found a 13% motor/sensory complication rate in patients who underwent femoral nerve block for pain control after anterior cruciate ligament reconstruction. Although these deficits may persist, they are not permanent and are not different when compared with controls at 9-month follow-up. However, maximal strength and function are not fully restored at normal return to play time and rehabilitation should continue long term to maximize recovery. Level I, prospective randomized trial.

Comparison of Frontozygomatic versus Sigmoid Notch Approach for Extraoral Maxillary Nerve Block Anesthesia: A Prospective Clinical Trial

With definitive indications, extraoral techniques of achieving regional nerve blocks are a boon to oral and maxillofacial surgical practice. Though less commonly practiced, since general anesthesia is more favored, certain medical conditions favor the use of regional nerve blocks over general anesthesia. To block the maxillary nerve extraorally, sigmoid notch approach and frontozygomatic approach have been previously described in the literature, but a clinical trial comparing these techniques is sparse. This study attempts to compare both the approaches for their efficacies while paying an equal attention to the associated complications. Two hundred patients aged between 40-90years of ASA 1 and 2 category were equally divided into two groups and underwent extraction of maxillary teeth under local anesthesia using 2% lignocaine with 1:80,000 adrenaline. Frontozygomatic approach to reach the foramen rotundum was employed in group A (n=100) and sigmoid notch approach in group B (n=100). Pain during injection, time required for onset of subjective and objective symptoms of anesthesia and duration of anesthesia were the study parameters. Associated complications were documented and discussed. Student's unpaired t test was used for statistical evaluation. Although both the techniques were found to be feasible, statistical evaluations favored the frontozygomatic approach with respect to faster onset and a longer duration of the anesthetic effect. The anatomical considerations in either techniques suggested that the incidence of potential complications of accidental entry of the needle into the orbit, skull and vessel injuries was higher when using sigmoid notch approach as against the frontozygomatic approach. Though sigmoid notch approach, described widely in the literature, can be employed successfully, certain anatomical considerations and technical modifications in the frontozygomatic approach have made the latter a more practical and feasible approach. When both the maxillary and the mandibular nerves need to be blocked simultaneously, sigmoid notch may be employed, but isolated maxillary nerve block is better achieved using frontozygomatic approach.

Comparison of Time to Operation and Efficacies of Ultrasound-Guided Nerve Block and General Anesthesia in Emergency External Fixation of Lower Leg Fractures

Category: Ankle, Trauma Introduction/Purpose: This prospective study aimed to evaluate the usefulness of ultrasound (US)-guided nerve block (NB) for emergency external fixation of lower leg fractures, by investigating real time before the operation and the clinical result according to the anesthesia method (US-guided NB or general anesthesia [GA]). Methods: From June 2014 to April 2016, 40 patients who underwent emergency surgery for external fixator application were enrolled in this study. We performed a randomized trial for US-guided NB and GA. We measured the lead time before the start of the operation after the decision to perform emergency surgery in both groups. Results: The US-guided NB group comprised 17 men and 3 women with a median age of 55.6 (33–77) years. Twelve of these patients had conditions such as diabetes mellitus, hypertension, and kidney-related diseases. Fracture types 42, 43, and 44 in the AO classification were observed in 3, 12, and 5 cases, respectively. The average time taken to emergency operation was 4.3 (2– 6.25) h. However, in the GA group, the average time taken to emergency operation was 9.4 (3–14) h. In the US-guided NB group, no cases of anesthesia failure and unstable vital signs during the operation occurred. Moreover, there were no postoperative complications related to the anesthesia method, such as aggravation of the general condition. Conclusion: Emergency external fixation with US-guided NB in patients with lower-extremity trauma can be implemented in less time regardless of preoperative preparation, which is a requirement in GA.

Transabdominal Breast Augmentation: A Review of 114 Cases Performed over 14 Years.

Abdominoplasty patients are frequently candidates for breast rejuvenation as well. Transabdominal breast augmentation permits insertion of breast implants through the abdominoplasty incision. This combined procedure is preferentially performed in an outpatient setting under monitored anesthesia care and nerve blocks. This study was a 14-year retrospective review of a single surgeon's technique and outcomes using transabdominal breast augmentation through a low transverse abdominoplasty incision in select patients requesting simultaneous abdominoplasty and bilateral breast augmentation. Patients had minimal ptosis, smoking cessation a minimum of 4 weeks before surgery and indefinitely thereafter, and a lack of superior abdominal or significant breast surgery. The study's 114 patients had a mean follow-up of 19.2 months. The procedure was performed under monitored anesthesia care with intercostal nerve blocks for most patients [n = 107 (93.9 percent)] and general anesthesia [n = 7 (6.1 percent)] for a few. Seventy-nine patients [n = 74 (64.9 percent)] underwent additional procedures, with most (n = 48) undergoing suction-assisted lipectomy. Many patients underwent multiple procedures. Most complications occurred predictably along the central distal abdominoplasty flap and were minor (small wound breakdown, seroma, and mild skin infection). Major complications [n = 8 (7.0 percent)] included two patients with implant malposition requiring revision and one patient with a Baker grade III capsule; notably, this patient was a half-pack-per-day smoker with a body mass index of 27 kg/m. Transabdominal breast augmentation is a safe, reliable procedure in the appropriately selected, healthy patient and may be used in minimally to moderately ptotic patients who request concurrent breast augmentation and abdominoplasty. Morbidity compares favorably to reported abdominoplasty series in the appropriately selected patient. Therapeutic, IV.

Comparison of Time to Operation and Efficacies of Ultrasound-Guided Nerve Block and General Anesthesia in Emergency External Fixation of Lower Leg Fractures (AO 42, 43, 44)

The present randomized controlled trial evaluated the usefulness of ultrasound (US)-guided nerve block (NB) for emergency external fixation of lower leg fractures, by investigating the time required before surgery and the clinical results stratified by the anesthesia method (US-guided NB or general anesthesia [GA]). From June 2014 to April 2016, 40 patients who had undergone emergency surgery for external fixator application were enrolled in the present study. We measured the lead time before the start of surgery after the decision to perform emergency surgery in both groups. The US-guided NB group included 17 males (85%) and 3 females (15%), with a mean age of 55.6 (range 33 to 77) years. Of these 20 patients, 12 (60%) had comorbidities such as diabetes mellitus, hypertension, and kidney-related disease. Fracture type 42, 43, and 44 in the AO classification were observed in 3 (15%), 12 (60%), and 5 (25%) cases, respectively. The mean interval before emergency surgery was 4.3 (range 2 to 6.25) hours in the US-guided NB group. In the GA group (n = 20 patients), the mean interval before emergency surgery was 9.4 (range 3 to 14) hours, and this difference was statistically significant (p < .001). In the US-guided NB group, no cases of anesthesia failure or unstable vital signs occurred during surgery. Also, no postoperative complications related to the anesthesia method, such as aggravation of the general condition, developed. In contrast, 1 case of postoperative atelectasis occurred in the GA group. Emergency external fixation with US-guided NB in patients with lower extremity trauma can be implemented in less time, regardless of the preoperative preparation, which is a requirement for GA.

A comparative study between 0.5% centbucridine and 2% lignocaine with adrenaline (1:200,000) for bilateral extraction of mandibular premolar using nerve block anesthesia: a double blind randomized controlled clinical study

Background: The purpose of the study was to compare the efficacy of 0.5% centbucridine and 2% lignocaine with adrenaline (1:200,000).Methods: A clinical prospective, controlled, randomized, double blind group study was conducted on 22 patients referred for extraction of mandibular premolars, who were randomly assigned to 2 groups by the split mouth method. Before extraction of mandibular premolar, either 0.5% centbucridine or 2% lignocaine with 1:200,000 adrenaline were used for anesthesia. All the patients were given inferior alveolar, lingual, and long buccal nerve blocks. Pain on injection, onset of anesthesia, duration of anesthesia and changes in blood pressure and pulse rate were monitored and recorded.Results: In our study, statistically significant difference was found between the efficacy of agents as for time for onset of anesthesia, duration of action, and changes in blood pressure and pulse rate, but no statistically significant difference was found for pain on injection between two groups.Conclusions: The efficacy of centbucridine was found to be more as compared to lignocaine with adrenaline, in rapid onset of anesthesia, longer duration of action, and cardiovascular stability. There was no significant difference in the pain on injection for both centbucridine and lignocaine with adrenaline. Centbucridine can be used in medically compromised condition where adrenaline is contraindicated.

The efficacy of pain relief by nerve block anesthesia for arthroscopic rotator cuff repair

The efficacy of pain relief by nerve block anesthesia for arthroscopic rotator cuff repair

The efficacy of pain relief by nerve block anesthesia for arthroscopic rotator cuff repair

The efficacy of pain relief by nerve block anesthesia for arthroscopic rotator cuff repair

Delayed Recovery of Motor Block Following Radiofrequency Ablation of Varicose Veins with Femoral Nerve Block and Tumescent Anesthesia

Femoral nerve block with tumescent anesthesia is used to perform the radiofrequency ablation of varicose veins. The surgery can be done as day-case. But if recovery from motor block is delayed, it can make hospital discharge difficult. Prolonged femoral nerve blocks with motor blockade of the quadriceps have been noted after the use of bupivacaine. The motor blockade lasted up to 30–40 hours when 15–30 mL of 0.5% bupivacaine was used. However, it was rarely reported in ropivacaine. We report that femoral nerve block with 15 mL of 0.375% ropivacaine induced prolonged motor blockade up to 30 hours.

Chronic Dyspnea - Running

HISTORY: 63 year-old male presented to clinic with complaint of continued severe shortness of breath status-post left total shoulder arthroplasty. Surgery was performed under general anesthesia with interscalene nerve block for regional anesthesia. Previously, patient had been running 3 miles per day and golfing regularly without issues. Immediately after the surgery, he began to notice a significant decrease in his functional status due to SOB. He now has difficulty walking up one flight of stairs, cutting the grass, or golfing more than 9 holes because of the SOB he experiences with activity. Denies fevers, chills, cough, hemoptysis, chest pain, palpitations, and calf pain. He is otherwise very happy with the improvements in pain, ROM, and overall functionality of his left shoulder s/p left TSA. PHYSICAL EXAMINATION: VS: BP 132/76, P 66, Temp 36.7 C, Resp 18, SpO2 96%; Gen: Awake, alert, cooperative, NAD; Lungs: No increased work of breathing, good air exchange, CTAB, No rales or wheezing; CV: RRR, +S1S2, no S3 or S4, no murmurs noted; Neuro: AOx3, sensation to light touch intact throughout LUE, no focal deficits; Skin: Surgical incisions clean, dry, and intact DIFFERENTIAL DIAGNOSIS: 1. Atelectasis 2. Pulmonary Embolism 3. Underlying pulmonary condition (COPD vs. pulmonary fibrosis vs. lung carcinoma) 4. Congestive heart failure 5. Diaphragmatic paralysis from phrenic nerve injury TEST AND RESULTS: CTA Chest: significant pleural effusion, negative for PE; CXR: elevated left hemi-diaphragm FINAL WORKING DIAGNOSIS: Left diaphragmatic paralysis secondary to phrenic nerve injury associated with interscalene block TREATMENT AND OUTCOMES: 1. Patient initially on Aspirin and encouraged to ambulate for DVT prophylaxis 2. Provided with an incentive spirometer to prevent post-op atelectasis 3. Extensive outpatient Cardiology and Pulmonology evaluations without findings of underlying medical condition to explain symptoms 4. Suspected phrenic nerve injury associated with pre-operative interscalene block 5. Pulmonary rehabilitation performed with minimal improvement symptoms 6. We have discussed the possibility of further pulmonary rehabilitation vs. neurosurgical consultation for possibility of phrenic nerve decompression with possible nerve graft

AnAnkle Trial study protocol: a randomised trial comparing pain profiles after peripheral nerve block or spinal anaesthesia for ankle fracture surgery

IntroductionAnkle fracture surgery is a common procedure, but the influence of anaesthesia choice on postoperative pain and quality of recovery is poorly understood. Some authors suggest a benefit of peripheral...

Consensus recommendations for anaesthetic peripheral nerve block

IntroductionAnaesthetic block, alone or in combination with other treatments, represents a therapeutic resource for treating different types of headaches. However, there is significant heterogeneity in patterns of use among different professionals. DevelopmentThis consensus document has been drafted after a thorough review and analysis of the existing literature and our own clinical experience. The aim of this document is to serve as guidelines for professionals applying anaesthetic blocks. Recommendations are based on the levels of evidence of published studies on migraine, trigeminal autonomic cephalalgias, cervicogenic headache, and pericranial neuralgias. We describe the main technical and formal considerations of the different procedures, the potential adverse reactions, and the recommended approach. ConclusionAnaesthetic block in patients with headache should always be individualised and based on a thorough medical history, a complete neurological examination, and expert technical execution.

A novel transperitoneal abdominal wall nerve block for postoperative pain in laparoscopic colorectal surgery

Although the laparoscopic approach reduces pain associated with abdominal surgery, postoperative pain remains a problem. Ultrasound-guided rectus sheath block and transversus abdominis plane block have become increasingly popular means of providing analgesia for laparoscopic surgery. Ninety patients were enrolled in this study. A laparoscopic puncture needle was inserted via the port, and levobupivacaine was injected into the correct plane through the peritoneum. The patients' postoperative pain intensity was assessed using a numeric rating scale. The effects of laparoscopic nerve block versus percutaneous anesthesia were compared. This novel form of transperitoneal anesthesia did not jeopardize completion of the operative procedures. The percutaneous approach required more time for performance of the procedure than the transperitoneal technique. This new analgesia technique can become an optional postoperative treatment regimen for various laparoscopic abdominal surgeries. What we mainly want to suggest is that the transperitoneal approach has the advantage of a higher completion rate. A percutaneous technique is sometimes difficult with patients who have severe obesity and/or coagulation disorders. Additional studies are required to evaluate its benefits.

Possible utility of contrast-enhanced ultrasonography for detecting spread of local anesthetic in nerve block.

This study demonstrated the effects of perfluorobutane (Sonazoid®) with contrast-enhanced ultrasonography (CEUS) to identify the spread of local anesthetics in ultrasound-guided nerve block. This study consists of simulation, cadaveric, and animal studies. In a simulation study, 1% lidocaine with 10- to 1000-fold diluted Sonazoid®, a US-specific contrast agent to diagnose hepatic and breast cancers (0.5mL), was injected into a resin-based phantom to determine the optimal concentration for ultrasound-guided peripheral nerve block. The enhanced area was measured by direct observation and ultrasonography (US). In the cadaver study, ultrasound-guided sciatic nerve block was performed at the popliteal fossa in the 9 extremities, and 5mL of the optimally diluted Sonazoid® defined in the simulation study with X-ray contrast medium and blue dye was injected. Longitudinal spread of the solution was measured by CEUS, X-ray imaging and anatomical dissection. In the animal study, the optimally diluted Sonazoid® was injected around the sciatic nerve of rats (n=6), and neuronal function and toxicity were evaluated by behavioral and histological estimation. The simulation study proved that 100-fold diluted Sonazoid® was the optimal concentration. In the cadaver study, CEUS and anatomical dissection (r=0.90, P=0.0020) or radiography (r=0.84, P=0.0072) showed high agreement and correlation with the longitudinal spread. CEUS clearly showed a fine intraneuronal injection image compared to the usual B-mode imaging. The animal study suggested no adverse effects by co-administration of lidocaine and Sonazoid®. CEUS with 100-fold diluted Sonazoid® could identify the spread of local anesthetic as well as radiography and anatomical dissection, and distinguish between intra- and extraneuronal injections without neurodegeneration.