The effect of spinal versus general anaesthesia on perioperative muscle weakness in patients having bilateral total hip arthroplasty: a single center randomized clinical trial.

BACKGROUND: Perioperative neuro-endocrine stress response may contribute to acquired muscle weakness. Regional anaesthesia has been reported to improve the outcome of patients having total hip arthroplasty. In this study, it was hypothesized that spinal anaesthesia (SA) decreases the perioperative neuro-endocrine stress response and perioperatively acquired muscle weakness (PAMW), as compared to general anaesthesia (GA). METHODS: Fifty subjects undergoing bilateral total hip arthroplasty (THA) were randomly allocated to receive a standardized SA (n = 25) or GA (n = 25). Handgrip strength was assessed preoperatively, on the first postoperative day (primary endpoint) and on day 7 and 28. Respiratory muscle strength was measured by maximal inspiratory pressure (MIP). Stress response was assessed by measuring levels of Adrenocorticotropic hormone (ACTH), cortisol and interleukin-6 (IL-6). RESULTS: Handgrip strength postoperatively (day 1) decreased by 5.4 ± 15.9% in the SA group, versus 15.2 ± 11.7% in the GA group (p = 0.02). The handgrip strength returned to baseline at day 7 and did not differ between groups at day 28. MIP increased postoperatively in patients randomized to SA by 11.7 ± 48.3%, whereas it decreased in GA by 12.2 ± 19.9% (p = 0.04). On day 7, MIP increased in both groups, but more in the SA (49.0 ± 47.8%) than in the GA group (14.2 ± 32.1%) (p = 0.006). Postoperatively, the levels of ACTH, cortisol and IL-6 increased in the GA, but not in the SA group (p < 0.004). CONCLUSION: In patients having bilateral THA, SA preserved the postoperative respiratory and peripheral muscle strength and attenuated the neuro-endocrine and inflammatory responses. TRIAL REGISTRATION: clinicaltrials.gov NCT03600454.

The effects of intrathecal morphine on urinary bladder function and recovery in patients having a cesarean delivery - A randomized clinical trial.

INTRODUCTION: Spinal anesthesia with intrathecal morphine (ITM) is a common anesthesia technique for cesarean delivery. The hypothesis was that the addition of ITM will delay micturition in women undergoing cesarean delivery. METHODS: Fifty-six ASA physical status I and II women scheduled to undergo elective cesarean delivery under spinal anesthesia were randomized to the PSM group (50 mg prilocaine + 2.5 mcg sufentanil + 100 mcg morphine; n = 30) or PS group (50 mg prilocaine + 2.5 mcg sufentanil; n = 24). The patients in the PS group received a bilateral transverse abdominal plane (TAP) block. The primary outcome was the effect of ITM on the time to micturition and the secondary outcome was the need for bladder re-catheterization. RESULTS: The time to first urge to urinate (8 [6-10] hours in the PSM group versus 6 [4-6] hours in the PS group) and the time to first micturition (10 [8-12] hours in the PSM group versus 6 [6-8] hours in the PS group) were significantly (p < 0.001) prolonged in the PSM group. Two patients in the PSM group met the 800 mL criterium for urinary catheterization after 6 and 8 h respectively. CONCLUSION: This study is the first randomized trial to demonstrate that the addition of ITM to the standardized mixture of prilocaine and sufentanil significantly delayed micturition.

A novel infrapatellar approach of ultrasound-guided intra-articular injection of the knee from both lateral and medial side: a case series.

Knee osteoarthritis (OA) is common. Ultrasound-guided intra-articular injection (UGIAI) using the superolateral approach is currently the gold standard for treating knee OA, but it is not 100% accurate, especially in patients with no knee effusion. Herein, we present a case series of chronic knee OA treated with a novel infrapatellar approach to UGIAI. Five patients with chronic grade 2-3 knee OA, who had failed on conservative treatments and had no effusion but presented with osteochondral lesions over the femoral condyle, were treated with UGIAI with different injectates using the novel infrapatellar approach. The first patient was initially treated using the traditional superolateral approach, but the injectate was not delivered intra-articularly and became trapped in the pre-femoral fat pad. The trapped injectate was aspirated in the same session due to interference with knee extension, and the injection was repeated using the novel infrapatellar approach. All patients who received the UGIAI using the infrapatellar approach had the injectates successfully delivered intra-articularly, as confirmed with dynamic ultrasound scanning. Their Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, stiffness, and function scores significantly improved 1 and 4 weeks post-injection. UGIAI of the knee using a novel infrapatellar approach is readily learned and may improve accuracy of UGIAI, even for patients with no effusion.

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.

Motor-Sparing Nerve Blocks Can Improve the Results of Digit Tendon Surgery: A Case Report.

A 56-year-old woman presented with flexion dysfunction of the fifth digit 6 weeks after surgical repair of a flexor digitorum profundus laceration. She was scheduled for surgical adhesiolysis and restoration of the functionality of the finger. Intraoperative monitoring of the range of motion by active flexion was deemed important to prevent incomplete release of the tendon and residual dysfunction. Distal median and ulnar nerve blocks were used for anesthesia with the patient's ability to flex the finger. This case suggests that motor-sparing peripheral nerve blocks can improve functional outcome in certain hand surgeries.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks.

BACKGROUND: There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques. METHODS: We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement. RESULTS: Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified. CONCLUSIONS: Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

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.

Neurotoxicity of bupivacaine and liposome bupivacaine after sciatic nerve block in healthy and streptozotocin-induced diabetic mice.

BACKGROUND: Long-acting local anaesthetics (e.g. bupivacaine hydrochloride) or sustained-release formulations of bupivacaine (e.g. liposomal bupivacaine) may be neurotoxic when applied in the setting of diabetic neuropathy. The aim of the study was to assess neurotoxicity of bupivacaine and liposome bupivacaine in streptozotocin (STZ) - induced diabetic mice after sciatic nerve block. We used the reduction in fibre density and decreased myelination assessed by G-ratio (defined as axon diameter divided by large fibre diameter) as indicators of local anaesthetic neurotoxicity. RESULTS: Diabetic mice had higher plasma levels of glucose (P < 0.001) and significant differences in the tail flick and plantar test thermal latencies compared to healthy controls (P < 0.001). In both diabetic and nondiabetic mice, sciatic nerve block with 0.25% bupivacaine HCl resulted in a significantly greater G-ratio and an axon diameter compared to nerves treated with 1.3% liposome bupivacaine or saline (0.9% sodium chloride) (P < 0.01). Moreover, sciatic nerve block with 0.25% bupivacaine HCl resulted in lower fibre density and higher large fibre and axon diameters compared to the control (untreated) sciatic nerves in both STZ-induced diabetic (P < 0.05) and nondiabetic mice (P < 0.01). No evidence of acute or chronic inflammation was observed in any of the treatment groups. CONCLUSIONS: In our exploratory study the sciatic nerve block with bupivacaine HCl (7 mg/kg), but not liposome bupivacaine (35 mg/kg) or saline, resulted in histomorphometric indices of neurotoxicity. Histologic findings were similar in diabetic and healthy control mice.

Peripheral nerve catheters: A critical review of the efficacy.

Continuous peripheral nerve blocks are commonly used for postoperative analgesia after surgery. However, catheter failure may occur due to either primary (incorrect insertion) or secondary reasons (displacement, obstruction, disconnection). Catheter failure results in unanticipated pain, need for opioid use, and risk of readmission or delay in hospital discharge. This review aimed to assess definition and frequency of catheter failure, and discuss the alternatives to prolong duration of single-shot nerve blocks. A literature search was performed on peripheral catheters reporting failure as the main outcome measure. Thirty-three studies met the selection criteria, comprising 2711 catheters. Literature review suggests that peripheral nerve catheters have clinically significant failure rate when the assessment is performed using an objective (imaging) method. Subjective methods of assessment (without imaging) may underestimate the incidence of catheter failure.

Supra-inguinal injection for fascia iliaca compartment block results in more consistent spread towards the lumbar plexus than an infra-inguinal injection: a volunteer study.

BACKGROUND AND OBJECTIVES: Lumbar plexus block has been used to provide postoperative analgesia after lower limb surgery. The fascia iliaca compartment block (FICB) has been proposed as an anterior approach of the lumbar plexus targeting the femoral, obturator and lateral femoral cutaneous nerve. However, both radiological and clinical evidence demonstrated that an infra-inguinal approach to the fascia iliaca compartment does not reliably block the three target nerves.We hypothesized that a supra-inguinal approach of the fascia iliaca compartment results in a more consistent block of the three target nerves than an infra-inguinal approach. METHODS: We performed a randomized controlled, double-blind trial in 10 healthy volunteers. Both an infra-inguinal FICB (I-FICB) and a supra-inguinal FICB (S-FICB) were performed on the left or the right side in each volunteer. Forty milliliters of lidocaine 0.5% was injected with each approach. Sensory and motor block and spread of local anesthetics (LA) on MRI were assessed. RESULTS: After an S-FICB, 80% of the volunteers had a complete sensory block of the medial, anterior and lateral region of the thigh, compared with 30% after an I-FICB (p=0.035). There was an insignificant effect on motor function with both approaches. After an S-FICB, in 8 out of 10 volunteers there was spread of LA in the expected anatomic location of the obturator nerve on MRI compared with 1 out of 10 volunteers after an I-FICB (p=0.0017). The cranial spread of LA after an S-FICB on MRI was higher than after an I-FICB (p=0.007), whereas there was a more caudal spread of LA on MRI after an I-FICB than after an S-FICB (p=0.005). CONCLUSIONS: An S-FICB produces a more complete sensory block of the medial, anterior and lateral region of the thigh, compared with an I-FICB. Our study demonstrates that an S-FICB with 40 mL of LA more reliably spreads LA to the anatomical location of the three target nerves of the lumbar plexus on MRI than an I-FICB. An S-FICB also leads to a more consistent spread in a cranial direction under the fascia iliaca and around the psoas muscle. CLINICAL TRIAL REGISTRATION: This work was registered with the European clinical trial registry: Identifier Eudra CT 2015-004607-24.

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.

Extended release bupivacaine formulations for postoperative analgesia: an update.

PURPOSE OF REVIEW: New formulations of local anesthetics with sustained release and longer duration of action are being developed to improve patient outcomes following surgery. This review summarizes the efficacy and safety of the three most recently developed extended-release formulations of the local anesthetic, bupivacaine. RECENT FINDINGS: Bupivacaine liposome injectable suspension (EXPAREL) encapsulates bupivacaine in biodegradable liposomes. It is currently the only extended-release formulation of bupivacaine approved by the FDA for infiltration of the tissues during surgery and for interscalene nerve block analgesia following shoulder surgery. SABER-Bupivacaine and HTX-011, are extended-release bupivacaine products in active development. Available data suggest relative safety and efficacy of all three formulations, although more data are needed to define their indications and dosing. SUMMARY: Extended-release bupivacaine formulations are promising alternatives to prolong duration of analgesia. To date, only EXPAREL has been approved by the FDA for tissue infiltration during surgery and for interscalene nerve block.

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.