Prospective evaluation of the safety of ultrasound-guided cervical medial branch blocks using the in-plane technique.

BACKGROUND: While fluoroscopic guidance is currently the imaging standard for cervical medial branch blocks (CMBBs), ultrasound guidance (USG) offers several potential safety advantages such as real-time needle visualization and the ability to detect and avoid critical soft tissue vascular or neural structures. However, no large-scale trials have examined the safety of USG for CMBB. METHODS: Five hundred patients undergoing 2308 individual block levels were recruited using a prospective cohort design, and blocks were performed in an outpatient office setting using an in-plane USG technique. Primary outcomes included immediate block-related complication, as well as delayed occurrences, in the following 2 weeks. Vascular structures adjacent to the target area, as well as the occurrence of vascular breach, were recorded. RESULTS: Three minor immediate complications were noted (two subcutaneous hematomas, one vasovagal reaction) comprising 0.13% of blocks (0.03% to 0.38%; 95% two-sided CI), and no delayed events were recorded (0% to 0.16%; 97.5% one-sided CI). Blood vessels were detected and avoided in 8.2% of blocks, and vascular breach was noted in 0.52% of blocks (0.27% to 0.91%; 95% two-sided CI). CONCLUSION: When performed using an in-plane technique by experienced operators, USG CMBB was found to be safe, with rare minor immediate complications and no further adverse event reported in the following 2 weeks. TRIAL REGISTRATION NUMBER: NCT04852393.

Randomized clinical trial comparing pericapsular nerve group (PENG) block and periarticular local anesthetic infiltration for total hip arthroplasty.

BACKGROUND: This randomized trial compared pericapsular nerve group block and periarticular local anesthetic infiltration in patients undergoing primary total hip arthroplasty. We hypothesized that, compared with pericapsular nerve group block, periarticular local anesthetic infiltration would decrease the postoperative incidence of quadriceps weakness at 3 hours fivefold (ie, from 45% to 9%). METHODS: Sixty patients undergoing primary total hip arthroplasty under spinal anesthesia were randomly allocated to receive a pericapsular nerve group block (n=30) using 20 mL of adrenalized bupivacaine 0.50%, or periarticular local anesthetic infiltration (n=30) using 60 mL of adrenalized bupivacaine 0.25%. Both groups also received 30 mg of ketorolac, either intravenously (pericapsular nerve group block) or periarticularly (periarticular local anesthetic infiltration), as well as 4 mg of intravenous dexamethasone.Postoperatively, a blinded evaluator carried out sensory assessment and motor assessment (knee extension and hip adduction) at 3, 6 and 24 hours. Furthermore, the blinded observer also recorded static and dynamic pain scores at 3, 6, 12, 18, 24, 36 and 48 hours; time to first opioid request; cumulative breakthrough morphine consumption at 24 hours and 48 hours; opioid-related side effects; ability to perform physiotherapy at 6, 24 and 48 hours; as well as length of stay. RESULTS: There were no differences in quadriceps weakness at 3 hours between pericapsular nerve group block and periarticular local anesthetic infiltration (20% vs 33%; p=0.469). Furthermore, no intergroup differences were found in terms of sensory block or motor block at other time intervals; time to first opioid request; cumulative breakthrough morphine consumption; opioid-related side effects; ability to perform physiotherapy; and length of stay. Compared with pericapsular nerve group block, periarticular local anesthetic infiltration resulted in lower static pain scores (at all measurement intervals) and dynamic pain scores (at 3 and 6 hours). CONCLUSION: For primary total hip arthroplasty, pericapsular nerve group block and periarticular local anesthetic infiltration result in comparable rates of quadriceps weakness. However, periarticular local anesthetic infiltration is associated with lower static pain scores (especially during the first 24 hours) and dynamic pain scores (first 6 hours). Further investigation is required to determine the optimal technique and local anesthetic admixture for periarticular local anesthetic infiltration. TRIAL REGISTRATION NUMBER: NCT05087862.

Randomized comparison between perineural dexamethasone and combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block.

BACKGROUND: This randomized trial compared perineural dexamethasone with combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block. We hypothesized that the combination of perineural adjuvants would result in a longer motor block. METHODS: Fifty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (2 mg) or combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg). After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min), the onset time (defined as the time required to reach a minimal composite score of 14 points) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids or general anesthesia).Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block and postoperative analgesia. RESULTS: No intergroup differences were observed in terms of success rate, onset time and surgical anesthesia. Compared with dexamethasone alone, combined dexamethasone-dexmedetomidine provided longer durations of motor block (21.5 (2.7) vs 17.0 (3.9) hours; p<0.001; 95% CI 2.6 to 6.4), sensory block (21.6 (3.6) vs 17.2 (3.6) hours; p<0.001; 95% CI 2.2 to 6.5), and postoperative analgesia (25.5 (9.4) vs 23.5 (5.6) hours; p=0.038; 95% CI 1.0 to 7.7). CONCLUSION: Compared with perineural dexamethasone (2 mg) alone, combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg) results in longer durations of sensorimotor block and analgesia. Further studies are required to determine the optimal dosing combination for dexamethasone-dexmedetomidine. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT04875039.

Randomized comparison between pericapsular nerve group (PENG) block and suprainguinal fascia iliaca block for total hip arthroplasty.

BACKGROUND: This randomized trial compared ultrasound-guided pericapsular nerve group block and suprainguinal fascia iliaca block in patients undergoing primary total hip arthroplasty. We selected the postoperative incidence of quadriceps motor block (defined as paresis or paralysis of knee extension) at 6 hours as the primary outcome. We hypothesized that, compared with suprainguinal fascia iliaca block, pericapsular nerve group block would decrease its occurrence from 70% to 20%. METHODS: Forty patients undergoing primary total hip arthroplasty under spinal anesthesia were randomly allocated to receive a pericapsular nerve group block (n=20) using 20 mL of adrenalized levobupivacaine 0.50%, or a suprainguinal fascia iliaca block (n=20) using 40 mL of adrenalized levobupivacaine 0.25%. After the performance of the block, a blinded observer recorded pain scores at 3, 6, 12, 18, 24, 36, and 48 hours; cumulative breakthrough morphine consumption at 24 and 48 hours; opioid-related side effects; ability to perform physiotherapy at 24 and 48 hours; as well as length of stay. Furthermore, the blinded observer also carried out sensory assessment (of the anterior, lateral, and medial aspects of the mid-thigh) and motor assessment (knee extension and hip adduction) at 3, 6, and 24 hours. RESULTS: Compared with suprainguinal fascia iliaca block, pericapsular nerve group block resulted in a lower incidence of quadriceps motor block at 3 hours (45% vs 90%; p<0.001) and 6 hours (25% vs 85%; p<0.001). Furthermore, pericapsular nerve group block also provided better preservation of hip adduction at 3 hours (p=0.023) as well as decreased sensory block of the anterior, lateral, and medial thighs at all measurement intervals (all p≤0.014). No clinically significant intergroup differences were found in terms of postoperative pain scores, cumulative opioid consumption at 24 and 48 hours, ability to perform physiotherapy, opioid-related side effects, and length of hospital stay. CONCLUSION: For primary total hip arthroplasty, pericapsular nerve group block results in better preservation of motor function than suprainguinal fascia iliaca block. Additional investigation is required to elucidate the optimal local anesthetic volume for motor-sparing pericapsular nerve group block and to compare the latter with alternate motor-sparing strategies such as periarticular local anesthetic infiltration. TRIAL REGISTRATION NUMBER: NCT04402450.

Lumbar plexus block versus suprainguinal fascia iliaca block for total hip arthroplasty: A single-blinded, randomized trial.

STUDY OBJECTIVE: Comparison of ultrasound-guided lumbar plexus block (LPB) and suprainguinal fascia iliaca block (SIFIB) in patients undergoing total hip arthroplasty (THA). DESIGN: Randomized equivalence trial. SETTING: University Hospital. PATIENTS: Sixty patients undergoing primary THA. INTERVENTIONS: Patients were randomly allocated to receive ultrasound-guided LPB (n = 30) or SIFIB (n = 30). The local anesthetic agent (40 mL of levobupivacaine 0.25% with epinephrine 5 µg/mL) and block adjuvant (4 mg of intravenous dexamethasone) were identical in all subjects. Postoperatively, all patients received patient-controlled intravenous analgesia (morphine) as well as acetaminophen and ketoprofen during 48 h. MEASUREMENTS: A blinded investigator recorded morphine consumption at 24 and 48 h as well as time to first morphine request, pain scores at 3, 6, 12, 24 and 48 h, incidence of adverse events, time to readiness for discharge, and length of hospital stay. The blinded investigator also carried out sensorimotor block assessment at 3, 6 and 24 h using a 10-point sensorimotor composite scale. MAIN RESULTS: No intergroup differences were found in terms of cumulative morphine consumption at 24 h (95% CI: -4.0 mg to 2.0 mg) and 48 h (95% CI, -5.0 mg to 2.0 mg) or time to first morphine request. Furthermore, pain scores were similar at all time intervals after 3 h. There were no intergroup differences in terms of composite sensorimotor scores at 3 and 6 h. However, SIFIB lasted longer than lumbar plexus block as evidenced by a higher composite score at 24 h. No intergroup differences were found in terms of complications. Compared with LPB, SIFIB was associated with shorter time to readiness for discharge (3 [1-4] vs. 2 [1-3] days; P = 0.042) and length of hospital stay (3 [2-5] vs. 3 [2-4] days; P = 0.048). CONCLUSIONS: For THA, no differences were found between LPB and SIFIB in terms of breakthrough morphine requirement and pain control. However, SIFIB resulted in a longer block and was associated with shorter time to readiness for discharge as well as decreased hospital stay.

Single- versus double-injection costoclavicular block: a randomized comparison.

BACKGROUND: The costoclavicular approach targets the brachial plexus in the proximal infraclavicular fossa, where the lateral, medial, and posterior cords are tightly bundled together. This randomized trial compared single- and double-injection ultrasound-guided costoclavicular blocks. We selected onset time as the primary outcome and hypothesized that, compared with its single-injection counterpart, the double-injection technique would result in a swifter onset. METHODS: Ninety patients undergoing upper limb surgery (at or below the elbow joint) were randomly allocated to receive a single- (n=45) or double-injection (n=45) ultrasound-guided costoclavicular block. The local anesthetic agent (35 mL of lidocaine 1%-bupivacaine 0.25%with epinephrine 5 µg/mL and 2 mg of preservative-free dexamethasone) was identical in all subjects. In the single-injection group, the entire volume of local anesthetic was injected between the three cords of the brachial plexus. In the double-injection group, the first half of the volume was administered in this location; the second half was deposited between the medial cord and the subclavian artery. After the performance of the block, a blinded observer recorded the onset time (defined as the time required to achieve a minimal sensorimotor composite score of 14 out of 16 points), success rate (surgical anesthesia) and block-related pain scores. Performance time and the number of needle passes were also recorded during the performance of the block. The total anesthesia-related time was defined as the sum of the performance and onset times. RESULTS: Compared with its single-injection counterpart, the double-injection technique displayed shorter onset time (16.6 (6.4) vs 23.4 (6.9) min; p<0.001; 95% CI for difference 3.9 to 9.7) and total anesthesia-related time (22.5 (6.7) vs 28.9 (7.6) min; p<0.001). No intergroup differences were found in terms of success and technical execution (ie, performance time/procedural pain). The double-injection group required more needle passes than the single-injection group (2 (1-4) vs 1 (1-3); p<0.001). CONCLUSION: Compared with its single-injection counterpart, double-injection costoclavicular block results in shorter onset and total anesthesia-related times. Further investigation is required to determine if a triple-injection technique (with targeted local anesthetic injection around each cord of the brachial plexus) could further decrease the onset time. TRIAL REGISTRATION NUMBER: NCT03595514.

Ultrasound-guided L5 dorsal ramus block: validation of a novel technique.

BACKGROUND: Although the value of ultrasound-guided (USG) lumbar medial branch blocks (MBB) has previously been examined in several clinical trials, blocking the L5 dorsal ramus (DR) remains a technical challenge and we sought to examine the accuracy of a novel technique targeting this level. METHODS: In this prospective cohort study, 115 patients scheduled for an L4 MBB and L5 DR block underwent an ultrasound scan to assess their lower spine sonoanatomy. Subjects in whom the necessary landmarks could be visualized underwent a USG L5 DR block using a pivot technique, which involved redirecting a needle from its position on the L5 transverse process after an L4 MBB. Success was determined by a blinded observer who examined the contrast distribution on postprocedural X-ray images. In addition to the final needle position, performance time, the number of needle passes, and any complication were recorded. RESULTS: A total of 100 patients had a USG block and 15 patients (13%) were excluded because of poor landmark visibility. The latter group presented a significantly higher body mass index (38.90±7.50 vs 26.31±4.25 kg/m2, p=0.004). A total of five failures were noted (95% success rate), this included three patients with transitional anatomy in whom needles were placed at the wrong level and two cases of incomplete contrast coverage possibly related to the partial intravascular injection. Performance time was 153.93±41.56 s and the median number of needle passes was 2 (range 4). No significant complications were noted. CONCLUSION: The pivot technique provides a reliable approach for USG L5 DR ramus blocks. TRIAL REGISTRATION NUMBER: NCT03805906.

A Randomized Comparison between 4, 6 and 8 mL of Local Anesthetic for Ultrasound-Guided Stellate Ganglion Block.

BACKGROUND: Because it affords greater accuracy than landmark-based techniques, ultrasound guidance may reduce the volume of local anesthetic required for sympathetic blockade of the upper extremity. We hypothesized that 4 mL would provide a similar clinical effect when compared to larger volumes. METHODS: One hundred and two patients with chronic neuropathic pain of the upper extremity or face were randomly assigned to receive an ultrasound-guided (USG) stellate ganglion block (SGB) with either 4 mL (group A), 6 mL (group B) or 8 mL (group C) mL of 1.0% lidocaine. Skin temperatures of the face, hand, and axillary fold were measured bilaterally at baseline, 10, 20, and 30 min after the block. Our primary outcome was the relative increase in hand temperature on the blocked side at 30 min and our non-inferiority margin was -0.6 °C. Secondary outcomes included success rate (as defined by a relative temperature increase of ≥1.5 °C), pain relief, degree of ptosis and side-effects. RESULTS: The 95% confidence intervals for the difference of the means exceeded our non-inferiority margin (A versus B: -0.76 to 0.24; A versus C: -0.89 to 0.11) for temperature changes in the hand; however, success rates were similar (44, 45 and 55% for A, B and C respectively, p = 0.651). No intergroup differences were found in temperature-related outcomes for the other measurement sites (face, axilla). The incidence of minor side-effects was significantly higher in group C and no block-related complications were noted. CONCLUSIONS: We were unable to establish the non-inferiority of a 4 mL volume for sympathetic blockade of the hand. The clinical significance of these findings is unclear as success rates were similar between the different groups. In contrast, the 6- and 8 mL volumes were not associated with greater temperature changes in the face and axilla.

Randomized comparison between perineural dexamethasone and dexmedetomidine for ultrasound-guided infraclavicular block.

BACKGROUND: This randomized trial compared perineural dexamethasone (5 mg) and dexmedetomidine (100 µg) for ultrasound-guided infraclavicular brachial plexus block. We hypothesized that both adjuvants would result in similar durations of motor block and therefore designed the study as an equivalence trial (equivalence margin=3.0 hours). METHODS: One hundred and twenty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (5 mg) or dexmedetomidine (100 µg). Patients and operators were blinded to the nature of the perineural adjuvant. After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids, or general anesthesia). Heart rate and blood pressure were recorded before the block as well as during the first 2 hours after its performance. Furthermore, the level of sedation (using the Ramsay Sedation Scale) was recorded in the postanesthesia care unit. Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block, and postoperative analgesia. RESULTS: No intergroup differences were observed in terms of success rate and surgical anesthesia. Compared with dexmedetomidine, dexamethasone provided longer durations of motor block (17.4 (4.0) vs 14.3 (3.0) hours; p<0.001; 95% CI 1.7 to 4.5), sensory block (19.0 (4.0) vs 15.0 (3.2) hours; p<0.001; 95% CI 2.6 to 5.4), and analgesia (22.2 (3.6) vs 16.9 (3.9) hours; p<0.001; 95% CI 3.7 to 6.9). Dexmedetomidine resulted in lower heart rate and blood pressure after the performance of the block, as well as an increased level of sedation postoperatively. CONCLUSION: Compared with dexmedetomidine (100 µg), dexamethasone (5 mg) results in longer sensorimotor block and analgesic durations, as well as a decreased level of patient sedation. Further studies are required to compare dexamethasone and dexmedetomidine using different doses, local anesthetic agents, and approaches to the brachial plexus. TRIAL REGISTRATION NUMBER: NCT03610893.

Randomized comparison between epidural waveform analysis through the needle versus the catheter for thoracic epidural blocks.

BACKGROUND: Epidural waveform analysis (EWA) provides a simple confirmatory adjunct for loss of resistance (LOR): when the needle/catheter tip is correctly positioned inside the epidural space, pressure measurement results in a pulsatile waveform. Epidural waveform analysis can be carried out through the tip of the needle (EWA-N) or the catheter (EWA-C). In this randomized trial, we compared the two methods. We hypothesized that, compared with EWA-C, EWA-N would result in a shorter performance time. METHODS: One hundred and twenty patients undergoing thoracic epidural blocks for thoracic or abdominal surgery were randomized to EWA-N or EWA-C. In the EWA-N group, LOR was confirmed by connecting the epidural needle to a pressure transducer. After obtaining a satisfactory waveform, the epidural catheter was advanced 5 cm beyond the needle tip. In the EWA-C group, the epidural catheter was first advanced 5 cm beyond the needle tip after the occurrence of LOR. Subsequently, the catheter was connected to the pressure transducer to detect the presence of waveforms. In both study groups, the block procedure was repeated at different intervertebral levels until positive waveforms could be obtained (through the needle or catheter as per the allocation) or until a predefined maximum of three intervertebral levels had been reached. Subsequently, the operator administered a 4 mL test dose of lidocaine 2% with epinephrine 5 µg/mL through the catheter. An investigator present during the performance of the block recorded the performance time (defined as the temporal interval between skin infiltration and local anesthetic administration through the epidural catheter). Fifteen minutes after the test dose, a blinded investigator assessed the patient for sensory block to ice. Success was defined as a bilateral block in at least two dermatomes. Furthermore, postoperative pain scores, local anesthetic consumption, and breakthrough analgesic consumption were recorded. RESULTS: No intergroup differences were found in terms of performance time, success rate, postoperative pain, local anesthetic requirement, and breakthrough analgesic consumption. CONCLUSION: EWA can be carried out through the needle or through the catheter with similar efficiency (performance time) and efficacy (success rate, postoperative analgesia). TRIAL REGISTRATION NUMBER: NCT03603574.

Dural puncture epidural analgesia for labor: a randomized comparison between 25-gauge and 27-gauge pencil point spinal needles.

BACKGROUND: This double-blind, randomized trial compared dural puncture epidural analgesia (DPEA) for labor using 25-gauge and 27-gauge pencil point spinal needles. We hypothesized that both needle sizes would result in similar onset time (equivalence margin=2.5 min) and therefore designed the study as an equivalence trial. METHODS: One hundred and forty patients undergoing labor were randomized to DPEA with 25-gauge (n=70) or 27-gauge (n=70) pencil point spinal needles. After the placement of the epidural catheter, a bolus of 20 mL of bupivacaine 0.125% and fentanyl 2 µg/mL was administered to all subjects. Thereafter, patients received boluses of 12 mL of bupivacaine 0.125% every 2 hours as needed.A blinded investigator recorded the onset time (defined as the temporal interval required to achieve a pain score ≤1 on a 0-10 scale), S2 block, sensory block height (30 min after the initial bolus of local anesthetic), presence of motor block (30 min after the initial bolus of local anesthetic), number of top-up doses required during labor and incidence of postural headache. RESULTS: Out of the 140 recruited patients, 135 were retained for analysis. Compared with their 27-gauge counterparts, 25-gauge pencil point spinal needles provided a 1.6 min shorter DPEA onset (95% CI of the difference of the means: -3.2 to -0.1 min). However, there were no intergroup differences in terms of S2 block, sensory block height, motor block, number of top-up doses and incidence of postural headache. CONCLUSION: Dural puncture epidural analgesia with 25-gauge pencil point spinal needles provides a 1.6 min shorter onset time than DPEA with 27-gauge spinal needles. Although statistically significant, such a difference may not be clinically relevant. Further investigation is required to compare 25-gauge and 27-gauge spinal needles for DPEA in the setting of different local anesthetic infusion strategies. TRIAL REGISTRATION NUMBER: NCT03389945.

Pain experiences and intrapersonal change among patients with chronic non-cancer pain after using a pain diary: a mixed-methods study.

OBJECTIVE: Pain diaries are a valuable self-assessment tool; however, their use in chronic non-cancer pain has received limited attention. In this study, we examined the effect of pain diary use on pain intensity, interference, and intrapersonal change in patients with chronic non-cancer pain. METHOD: A convergent mixed-methods design was used to prospectively evaluate a cohort of 72 patients. Daily pain intensity and weekly pain-interference were self-reported using pain diaries for a 4-week period. Outcomes were assessed by examining changes in pain scores (primary outcome) as well as the Brief Pain Inventory and Short-form McGill Pain Questionnaire-2. In addition, qualitative data obtained from pain diary entries and focus-group interviews were analyzed using thematic content analysis. RESULTS: Pain intensity and average pain scores were significantly lower after using the diaries. Participants reported less pain interference in mood, walking ability, normal work, and enjoyment of life. No differences were found in SF-MPQ-2 scores. Qualitative analysis indicated that better pain recognition and more effective communication with care providers led to improved self-management and more effectual treatment plans. CONCLUSION: Use of a pain diary in patients with chronic non-cancer pain was associated with reduced pain intensity and improved mood as well as function. Further controlled trials examining the long-term effects of pain diaries are warranted.

Randomized comparison between interscalene and costoclavicular blocks for arthroscopic shoulder surgery.

BACKGROUND: This randomized trial compared ultrasound-guided interscalene block (ISB) and costoclavicular brachial plexus block (CCB) for arthroscopic shoulder surgery. We hypothesized that CCB would provide equivalent analgesia to ISB 30 min after surgery without the risk of hemidiaphragmatic paralysis. METHODS: All 44 patients received an ultrasound-guided block of the intermediate cervical plexus. Subsequently, they were randomized to ISB or CCB. The local anesthetic agent (20 mL of levobupivacaine 0.5% and epinephrine 5 µg/mL) and pharmacological block adjunct (4 mg of intravenous dexamethasone) were identical for all study participants. After the block performance, a blinded investigator assessed ISBs and CCBs every 5 min until 30 min using a composite scale that encompassed the sensory function of the supraclavicular nerves, the sensorimotor function of the axillary nerve and the motor function of the suprascapular nerve. A complete block was defined as one displaying a minimal score of six points (out of a maximum of eight points) at 30 min. Onset time was defined as the time required to reach the six-point minimal composite score. The blinded investigator also assessed the presence of hemidiaphragmatic paralysis at 30 min with ultrasonography.Subsequently, all patients underwent general anesthesia. Postoperatively, a blinded investigator recorded pain scores at rest at 0.5, 1, 2, 3, 6, 12, and 24 hours. Patient satisfaction at 24 hours, consumption of intraoperative and postoperative narcotics, and opioid-related side effects (eg, nausea/vomiting, pruritus) were also tabulated. RESULTS: Both groups displayed equivalent postoperative pain scores at 0.5, 1, 2, 3, 6, 12, and 24 hours. ISB resulted in a higher incidence of hemidiaphragmatic paralysis (100% vs 0%; P < 0.001) as well as a shorter onset time (14.0 (5.0) vs 21.6 (6.4) minutes; p<0.001). However, no intergroup differences were found in terms of proportion of patients with minimal composite scores of 6 points at 30 min, intraoperative/postoperative opioid consumption, side effects, and patient satisfaction at 24 hours. CONCLUSION: Compared to ISB, CCB results in equivalent postoperative analgesia while circumventing the risk of hemidiaphragmatic paralysis. Further confirmatory trials are required. Future studies should also investigate if CCB can provide surgical anesthesia for arthroscopic shoulder surgery. CLINICAL TRIALS REGISTRATION: NCT03411343.

A multicenter, randomized comparison between 2, 5, and 8 mg of perineural dexamethasone for ultrasound-guided infraclavicular block.

BACKGROUND AND OBJECTIVES: This multicenter, randomized trial compared 2, 5, and 8 mg of perineural dexamethasone for ultrasound-guided infraclavicular brachial plexus block. Our research hypothesis was that all three doses of dexamethasone would result in equivalent durations of motor block (equivalence margin=3.0 hours). METHODS: Three hundred and sixty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block were randomly allocated to receive 2, 5, or 8 mg of preservative-free perineural dexamethasone. The local anesthetic agent (35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) was identical in all subjects. Patients and operators were blinded to the dose of dexamethasone. During the performance of the block, the performance time, number of needle passes, procedural pain, and complications (vascular puncture, paresthesia) were recorded. Subsequently a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min), onset time as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids, or general anesthesia). Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block, and postoperative analgesia. The main outcome variable was the duration of motor block. RESULTS: No intergroup differences were observed in terms of technical execution (performance time/number of needle passes/procedural pain complications), onset time, success rate, and surgical anesthesia. Furthermore, all three doses of dexamethasone provided similar durations of motor block (14.9-16.1 hours) and sensory block. Although 5 mg provided a longer analgesic duration than 2 mg, the difference (2.7 hours) fell within our pre-established equivalence margin (3.0 hours). CONCLUSIONS: 2, 5, and 8 mg of dexamethasone provide clinically equivalent sensorimotor and analgesic durations for ultrasound-guided infraclavicular block. Further trials are required to compare low (ie, 2 mg) and ultra-low (eg, 0.5-1 mg) doses of perineural dexamethasone for brachial plexus blocks. TRIAL REGISTRATION NUMBER: TCTR20150624001.