Effect of Lidocaine 2% Versus Bupivacaine 0.5% and 1 Versus 2 Dual Separate Injections on Onset and Duration of Ultrasound-Guided Wrist Blocks: A Blinded 2 × 2 Factorial Randomized Clinical Trial.

BACKGROUND: Local anesthetics are often selected or mixed to accomplish faster onset of anesthesia. However, with ultrasound guidance, local anesthetics are delivered with greater precision, which may shorten the onset time with all classes of local anesthetics. In this study, we compared onset time and duration of ultrasound-guided wrist blocks with a fast onset versus a longer lasting local anesthetic administered via single or dual (spatially separate) injections at the level of the midforearm. METHODS: In this randomized clinical trial, 36 subjects scheduled for carpal tunnel release were randomly assigned to receive ultrasound-guided median and ulnar nerve blocks with lidocaine 2% or bupivacaine 0.5% via single or dual injections (n = 9 in each group). Subjects fulfilled the study requirements. The main outcome variables were onset and duration of sensory blockade, which were tested separately in 2 (drug) × 2 (injection) analysis of variances (ANOVAs) with interaction terms. RESULTS: Sensory block onset time did not differ significantly between subjects given lidocaine 2% (9.2 ± 3.4 minutes) or bupivacaine 0.5% (9.5 ± 3.1 minutes) (P = .76; mean difference, -0.3 ± 1.1 minutes [95% confidence interval {CI}, -2.5 to 1.9]) or between the single- (9.6 ± 2.8 minutes) and dual- (9.1 ± 3.6 minutes) injection groups (P = .69; mean difference, -0.4 ± 1.1 minutes [95% CI, -1.8 to 2.6]). Sensory duration was longer for subjects in the bupivacaine 0.5% group (27.3 ± 11.6 hours) than for subjects in the lidocaine 2% group (8.4 ± 4.1 hours) (P < .001; 95% CI, 12.7-25.1). However, sensory duration in the single- (15.7 ± 12.5 hours) and dual- (19.4 ± 13.1 hours) injection groups did not differ significantly (P = .28; mean difference, -3.7 ± 4.3 hours [95% CI, -12.6 to 5.1]). CONCLUSIONS: No significant effect was found for onset time between lidocaine 2% and bupivacaine 0.5% used in ultrasound-guided wrist blocks. Dual injections did not shorten onset time. Since mean nerve block duration was longer with bupivacaine 0.5%, our results suggest that the selection of local anesthetic for the median and ulnar nerves at the level of the midforearm should be based on the desired duration of the block and not on its speed of onset.

Regional anesthesia in coronavirus disease 2019 pandemic.

PURPOSE OF REVIEW: Coronavirus disease 19 (COVID-19) has presented numerous challenges to healthcare systems worldwide. The virus is highly contagious and infectious since transmission can occur via multiple routes. General measures to prevent viral transmission to patients and healthcare personnel, such as a reduction in clinical load and routine testing, must be coupled with multiple additional safety measures in perioperative services. RECENT FINDINGS: Regional anesthesia preserves respiratory function and reduces aerosol-generating procedures typically associated with airway management in general anesthesia, making it the first choice for a suspected or confirmed COVID-19 patient in need of surgery with anesthesia. A well thought out regional anesthetic plan, implementation of hygiene and (personal) safety measures are necessary to ensure the best possible outcome for both the patient and the healthcare staff. SUMMARY: The present review addresses both practical and recommended measures for performing regional anesthesia in the pandemic, to ensure patient and staff safety, and equipment protection. Further research and evidence-based guidelines are necessary to devise an established standard of care during the current COVID-19 and possible future pandemics.

Distribution of Injectate and Sensory-Motor Blockade After Adductor Canal Block.

BACKGROUND: The analgesic efficacy reported for the adductor canal block may be related to the spread of local anesthetic outside the adductor canal. METHODS: Fifteen patients undergoing knee surgery received ultrasound-guided injections of local anesthetic at the level of the adductor hiatus. Sensory-motor block and spread of contrast solution were assessed. RESULTS: Sensation was rated as "markedly diminished" or "absent" in the saphenous nerve distribution and "slightly diminished" in the sciatic nerve territory without motor deficits. Contrast solution was found in the popliteal fossa. CONCLUSIONS: The spread of injectate to the popliteal fossa may contribute to the analgesic efficacy of adductor canal block.

The Disposition of Radiocontrast in the Interscalene Space in Healthy Volunteers.

BACKGROUND: We measured the spread of radiocontrast in the interscalene space after injection under low (<15 psi) and high (>20 psi) pressures. METHODS: Nine healthy volunteers received ultrasound-guided injections of 10 mL radio-opaque NaCl 0.9% in both interscalene spaces. Spread of injectate as assessed by computed tomography scan and discomfort on injection were recorded. RESULTS: Under both opening pressure conditions, injectate contacted 3 brachial plexus roots and spilled over the surface of the anterior and/or middle scalene muscles underneath the cervical fascia. CONCLUSIONS: Regardless of injection pressure, the interscalene space was filled with 10 mL of radiocontrast injectate.

Effective volume of ropivacaine 0.75% through a catheter required for interscalene brachial plexus blockade.

BACKGROUND: Ultrasound guidance during peripheral nerve blocks has allowed for reduction in dose and volume of local anesthetic required to accomplish successful blockade using multiple injections through a needle. The authors undertook this study to determine the minimal effective volume required to accomplish successful interscalene brachial plexus block (ISB) through the catheter. METHODS: After obtaining institutional ethics committee approval and written informed consent, patients aged 18-75 yr and scheduled for arthroscopic shoulder surgery under ISB were enrolled. All patients using a step-up/step-down method and the starting dose of 15 ml of 0.75% ropivacaine received an ultrasound-guided ISB catheter. The injection volume was increased or decreased by 1 ml in case of block failure or block success, respectively. RESULTS: The authors found that the proportion of patients with successful blockade increased sharply from approximately 57% at 6 ml to 100% by 7 ml, indicating that a small increase in volume of ropivacaine 0.75% markedly affects the success rate. A total of 12 ISB with injection volume less than 7 ml resulted in successful anesthesia within 30 min, yielding an ED95 of 7 ml (95% CI 6.8-7.2) ropivacaine 0.75%. For the group as a whole, the median (min-max) sensory block onset time was 5 (5-20) min, the median (min-max) motor blocks for the biceps and the deltoid muscles were 7.5 (5-15) min and 10 (5-15) min, respectively. The median (min-max) block duration was 8.9 (3-15) h. CONCLUSIONS: An injection of a minimum of 7 ml of ropivacaine 0.75% through the catheter is required for success rate and timely onset of surgical anesthesia with ISB.

Case report: ultrasound-guided continuous thoracic paravertebral block for outpatient acute pain management of multilevel unilateral rib fractures.

A 61-year-old man with multiple unilateral rib fractures (T3-T8) gained the ability to breathe deeply and to ambulate after ultrasound-guided continuous thoracic paravertebral block and was discharged home after being observed for 15 hours after the block. The ultrasound guidance was helpful in determining the site of rib fractures and the optimal level for catheter placement. This report also discusses the management of analgesia using continuous paravertebral block in an outpatient with trauma.

Standard approaches for upper extremity nerve blocks with an emphasis on outpatient surgery.

PURPOSE OF REVIEW: Currently, no standards exist with regard to the techniques and administration of ultrasound-guided peripheral nerve blocks. Consequently, the techniques and teaching substantially vary among practitioners and institutions. The purpose of this review is to propose a set of standard US-guided techniques for upper extremity nerve blocks. RECENT FINDINGS: On the basis of the synthesis of information in available literature and the consensus of an internationally recognized collaborative panel of regional anaesthesia experts, the review recommends a standardized approach to common upper extremity nerve blocks using ultrasound guidance. SUMMARY: A set of structured recommendations and approaches are suggested to help standardize clinical practice and teaching of ultrasound-guided upper extremity nerve blocks. Additional emphasis is placed on the discussion of nerve blocks in outpatient surgery.

Same Day Joint Replacement Surgery: Patient Selection and Perioperative Management.

Joint replacements are increasingly performed as outpatient surgeries. The push toward ambulatory joint arthroplasty is driven in part by the changing current health care economics and reimbursement models. Patients' selection and well-designed perioperative care pathways are critical for the success of these procedures. The rate of complications after outpatient joint arthroplasty is comparable to the rate of complications in the ambulatory setting. Patient education, adequate social support, multimodal analgesia, regional anesthesia are key ingredients to the ambulatory care pathway after joint arthroplasty. Motor sparing nerve blocks are often used in these settings. Implementation of the elements of fast protocols can result in overall improvement of outcome metrics for all patients undergoing joint arthroplasty, including reduced length of stay and increased rate of home discharge.

The minimum effective anesthetic volume of 0.75% ropivacaine in ultrasound-guided interscalene brachial plexus block.

BACKGROUND: The use of ultrasound to monitor needle placement and spread of local anesthetics (LA) has allowed reductions in the volume of LA required to anesthetize peripheral nerves. In the current study we investigated the minimal volume necessary to accomplish surgical anesthesia with interscalene brachial plexus block. METHODS: Twenty ASA physical status I-III patients, ages 18 to 75 years and scheduled for shoulder surgery under interscalene brachial plexus block, were enrolled. Using a previously validated step-up/step-down method, we determined the injection volume of 0.75% ropivacaine used for consecutive patients by the outcome of the preceding block. The starting volume was 15 mL (3 injections of 5 mL per each trunk); in the case of block failure, the volume was increased by 1 mL, whereas after successful block, the volume was reduced by 1 mL. The study was stopped upon achieving the secondary stopping rule of 10 consecutive successful interscalane blocks using 5 mL of ropivacaine 0.75%. Successful surgical anesthesia with the brachial plexus block was defined as presence of adequate motor block (motor score of ≤2 on 0 to 4 scale), absent sensation to cold and pinprick sensation within 30 minutes of injection, and absence of the need for general anesthesia for completion of surgery. Duration of sensory blockade was assessed by asking the patient to record the time of first pain sensation. RESULTS: Under our study conditions, successful surgical anesthesia for arthroscopic shoulder surgery can be achieved with 5 mL of 0.75% ropivacaine, or approximately 1.7 mL per each of the 3 trunks of the brachial plexus (superior, middle, and inferior). The study was stopped after 10 consecutive successful blocks with 5 mL of LA (100%, 95% confidence interval [CI]: 74.1%-100%). For the group as a whole, the median (range) sensory block onset time was 5 (5-20) minutes, the median (range) motor block for the biceps was 7.5 (5-15) minutes, and for abduction 10 (5-15) minutes. The median (range) block duration was 9.9 (5-19) hours, and the mean (SD) block performance time was 8.0 ± 3.2 minutes. Mean duration of analgesia was 9.9 ± 3.7 hours. Duration of analgesia was not associated with volume of LA (r = 0.05, P = 0.83). CONCLUSIONS: All patients in our study had successful surgical blocks with 5 mL of LA. However, the lower limit of the CI (calculated on the assumption of a single failure) does include the possibility of a 25% failure rate; thus studies using similar stopping rules for doses higher than 5 mL are nonetheless warranted.

Quadratus lumborum block: an imaging study of three approaches.

BACKGROUND AND OBJECTIVES: Different injection techniques for the quadratus lumborum (QL) block have been described. Data in human cadavers suggest that the transverse oblique paramedian (TOP) QL3 may reach the thoracic paravertebral space more consistently than the QL1 and QL2. However, the distribution of injectate in cadavers may differ from that in patients. Hence, we assessed the distribution of the injectate after the QL1, QL2, and TOP QL3 techniques in patients. MATERIALS AND METHODS: Thirty-four patients scheduled for abdominal surgery received QL blocks postoperatively; 26 patients received bilateral and 8 patients received unilateral blocks. Block injections were randomly allocated to QL1, QL2, or TOP QL3 techniques (20 blocks per each technique). The injections consisted of 18 mL of ropivacaine 0.375% with 2 mL of radiopaque contrast, injected lateral or posterior to the QL muscle for the QL1 and QL2 techniques, respectively. For the TOP QL3, the injection was into the plane between the QL and psoas muscles, proximal to the L2 transverse process. Two reviewers, blinded to the allocation, reviewed three-dimensional computed tomography (3D-CT) images to assess the distribution of injectate. RESULTS AND DISCUSSION: The QL1 block spread in the transversus abdominis plane (TAP), QL2 in the TAP, and posterior aspect of the QL muscle, whereas TOP QL3 spread consistently in the anterior aspect of the QL muscle with occasional spread to the lumbar and thoracic paravertebral areas. CONCLUSIONS: The spread of injectate after QL1, QL2, and QL3 blocks, resulted in different distribution patterns, primarily in the area of injection. The TOP QL3 did not result in consistent interfascial spread toward the thoracic paravertebral space.

Effect of Bupivacaine Liposome Injectable Suspension on Sensory Blockade and Analgesia for Dupuytren Contracture Release.

Purpose: To study the efficacy of bupivacaine liposome injectable suspension in prolonging sensory blocks of the median and ulnar nerves for subjects with Dupuytren contracture release by collagenase injection. We hypothesized that combining liposome bupivacaine and bupivacaine hydrochloride would extend the duration of blocks without added complications. Methods: We randomized 32 subjects scheduled for Dupuytren contracture release with collagenase Clostridium histolyticum injections to receive forearm blocks of the median and ulnar nerves with a mixture of 5 mL liposome bupivacaine 1.33% plus 2.5 mL bupivacaine hydrochloride 0.5% per nerve (n = 16) or 7.5 mL bupivacaine hydrochloride 0.5% alone per nerve (n = 16). Sensory block and analgesia were assessed through the first posttreatment week. Results: Sensory block was nearly 4 times longer in subjects who received the liposome bupivacaine mixture compared with subjects who received bupivacaine hydrochloride alone. Most subjects (13 of 16) who received the liposome bupivacaine mixture had adequate analgesia for finger manipulation to rupture the cords, whereas most subjects (15 of 16) who received bupivacaine hydrochloride alone required additional anesthesia. Subjects in the liposome mixture group reported lower pain scores through the first 3 days after treatment. There were no serious side effects. Conclusions: Addition of liposome bupivacaine to forearm blocks for Dupuytren contracture release prolonged sensory block and improved pain scores without increasing side effects or impairing hand function. Supplemental lidocaine injections for the painful phases of Dupuytren contracture release with collagenase C histolyticum injections were not required by most subjects who received liposome bupivacaine. Type of study/level of evidence: Therapeutic I.

Addition of Liposome Bupivacaine to Bupivacaine HCl Versus Bupivacaine HCl Alone for Interscalene Brachial Plexus Block in Patients Having Major Shoulder Surgery.

BACKGROUND AND OBJECTIVES: We examined whether liposome bupivacaine (Exparel) given in the interscalene brachial plexus block lowers pain in the setting of multimodal postoperative pain management for major shoulder surgery. METHODS: Fifty-two adult patients were randomized to receive either 5 mL of 0.25% bupivacaine HCl immediately followed by 10 mL of liposome bupivacaine 133 mg (n = 26) or 15 mL of 0.25% standard bupivacaine alone (n = 26) in interscalene brachial plexus block. The primary outcome (worst pain in the first postoperative week) was assessed by the Modified Brief Pain Inventory short form. Secondary outcomes were overall satisfaction with analgesia (OBAS), functionality of the surgical arm, sleep duration, time to first opioid (tramadol) request and opioid consumption (mEq), sensory-motor block characteristics, and the occurrence of adverse effects. RESULTS: Worst pain was lower in patients given liposome bupivacaine added to standard bupivacaine than in patients given standard bupivacaine alone (generalized estimating equation [GEE] estimated marginal mean values, 3.6 ± 0.3 vs 5.3 ± 0.4 points on the Numeric Rating Scale, respectively, although the effect was modest, 1.6 ± 0.5; 95% confidence interval, 0.8-2.5). Total OBAS scores indicated greater satisfaction (GEE estimated marginal mean values, 1.8 ± 0.3 vs 3.3 ± 0.4 on total OBAS, respectively, with modest effect, difference, 1.4 ± 0.5; 95% confidence interval, 0.5-2.4). There were no differences in any of the other secondary outcomes. CONCLUSIONS: Liposome bupivacaine added to standard bupivacaine may lower pain and enhance patient's satisfaction in the first postoperative week even in the setting of multimodal analgesia for major shoulder surgery.This study was registered with clinicaltrials.gov (NCT02554357) on July 11, 2015, by Principal Investigator Catherine Vandepitte, MD.

Dislocation of a femur fracture after femoral nerve block.

OBJECTIVE: Femoral nerve block (FNB) is increasingly used as an analgesic modality in patients with femoral fracture both in the emergency department and preoperatively. We describe an occurrence of unexpected dislocation of the fracture after FNB. CASE REPORT: An FNB was administered to treat pain in a 48-year-old patient with metastatic breast carcinoma and multiple bone metastases. A diagnostic FNB with 20 mL of 0.25% levobupivacaine resulted in analgesia but also in unexpected gross deformity in the proximal right femur. An x-ray revealed a pathologic fracture of the proximal third femur diaphysis, with reduction and angulation of fragments, necessitating urgent surgery. CONCLUSIONS: Femoral nerve block confers effective analgesia for femur fracture. However, relaxation of the quadriceps femoris muscle may destabilize the fracture because of an unopposed tone of the hamstrings and/or thigh adductors.

500th birthday of Andreas Vesalius, the founder of modern anatomy: "vivitur ingenio, caetera mortis erunt" ("genius lives on, all else is mortal").

It is often said that regional anesthesia is the practice of applied anatomy. Therefore, it is fitting that on the occasion of his 500th birthday, we celebrate the life and work of the brilliant Flemish anatomist, Andreas Vesalius (1514-1564), the founder of modern anatomy.

Feasibility and analgesic efficacy of the transversus abdominis plane block after single-port laparoscopy in patients having bariatric surgery.

PURPOSE: The transversus abdominis plane (TAP) block is a technique increasingly used for analgesia after surgery on the anterior abdominal wall. We undertook this study to determine the feasibility and analgesic efficacy of ultrasound-guided TAP blocks in morbidly obese patients. We describe the dermatomal spread of local anesthetic in TAP blocks administered, and test the hypothesis that TAP blocks decrease visual analog scale (VAS) scores. PATIENTS AND METHODS: After ethics committee approval and informed consent, 35 patients with body mass index >35 undergoing single-port sleeve gastrectomy (SPSG) were enrolled. All patients received balanced general anesthesia, followed by intravenous patient-controlled analgesia (IV-PCA; hydromorphone) postoperatively; all reported VAS >3 upon arrival to the recovery room. From the cohort of 35 patients having single-port laparoscopy (SPL), a sealed envelope method was used to randomly select ten patients to the TAP group and 25 patients to the control group. The ten patients in the TAP group received ultrasound-guided TAP blocks with 30 mL of 0.2% Ropivacaine injected bilaterally. The dermatomal distribution of the sensory block (by pinprick test) was recorded. VAS scores for the first 24 hours after surgery and opioid use were compared between the IV-PCA+TAP block and IV-PCA only groups. RESULTS: Sensory block ranged from T5-L1. Mean VAS pain scores decreased from 8 ± 2 to 4 ± 3 (P=0.04) within 30 minutes of TAP block administration. Compared with patients given IV-PCA only, significantly fewer patients who received TAP block had moderate or severe pain (VAS 4-10) after block administration at 6 hours and 12 hours post-surgery. However, cumulative consumption of hydromorphone at 24 hours after SPSG surgery was similar for both groups. CONCLUSION: Ultrasound-guided TAP blocks in morbidly obese patients are feasible and result in satisfactory analgesia following SPSG in the immediate postoperative period.