The Minimum Effective Anesthetic Volume of 0.75% Ropivacaine in Ultrasound-Guided Interscalene Brachial Plexus Block

A comparison of the continuous supraclavicular brachial plexus block using the proximal longitudinal oblique approach and the interscalene brachial plexus block for arthroscopic shoulder surgery: A randomised, controlled, double-blind trial

BACKGROUND

Continuous interscalene brachial plexus block (ISB) is widely used for arthroscopic shoulder surgery, but the incidence of hemidiaphragmatic paresis (HDP) has been reported to reach 100%. Several methods, including injections distal to the C5-C6 nerve roots, have been attempted to reduce the HDP incidence. However, catheter placement distal to the C5-C6 nerve roots interferes with the surgical site.

OBJECTIVE

Our primary objective was to describe a new technique, the supraclavicular brachial plexus block (SCB), using the proximal longitudinal oblique approach (PLO-SCB), which can facilitate catheter placement and, when compared with ISB, to test whether this would provide noninferior analgesia and spare the phrenic nerve.

DESIGN

Prospective, randomised, double-blind study.

SETTING

Operating rooms, postanaesthesia care unit, and wards.

PATIENTS

Seventy-six patients aged 20 to 80 years scheduled for arthroscopic shoulder surgery.

INTERVENTIONS

Patients were randomly assigned to the continuous PLO-SCB ( n  = 40) or the continuous ISB ( n  = 40) groups. All patients received an initial low-volume single-injection (5 ml 0.75% ropivacaine) followed by a patient-controlled infusion of 0.15% ropivacaine.

MAIN OUTCOME MEASURES

The primary outcomes were the incidence of HDP and pain scores. Secondary outcomes were respiratory function, postoperative analgesic consumption, sensory and motor function, and complications.

RESULTS

The HDP incidence was significantly lower in the PLO-SCB group than in the ISB group at 30 min after block injection: 0% (0 of 38 patients) and 73.7% (28 of 38 patients), respectively ( P  < 0.001). Similarly, at 24 h after surgery, the incidences were 23.7% (9 of 38 patients) and 47.4% (18 of 38 patients) in the PLO-SCB and ISB groups, respectively ( P  = 0.002). Median [IQR] NRS pain scores at rest measured after surgery in the ISB and PLO-SCB groups were similar: immediately after surgery, 1 [0 to 2] vs. 1 [0 to 1], P  = 0.06); at 30 min, 2 [0.25 to 2] vs. 1 [0 to 2], P  = 0.065); and at 24 h 2 [0.25 to 3] vs. 1 [0 to 3], P  = 0.47, respectively.

CONCLUSION

For major shoulder surgery, compared with continuous ISB, continuous PLO-SCB was more sparing of diaphragmatic and respiratory function while providing noninferior analgesia. Catheter placement via the PLO approach is feasible without interfering with the surgical field.

TRIAL REGISTRATION

Registered by the Clinical Trial Registry of Korea (Seoul, Korea; KCT0004759, http: cris.nih.go.kr, principal investigator: Hyungtae Kim).

The Minimum Effective Analgesic Volume of 0.5% Bupivacaine for Ultrasound-Guided Anterior Suprascapular Nerve Block

Objective The interscalene brachial plexus block (ISBB) constitutes the gold standard for analgesia after shoulder procedures. Ipsilateral phrenic nerve block remains the most common adverse effect after ISBB. Alternative nerve blocks are performed in shoulder surgery in order to prevent hemi-diaphragmatic paralysis (HDP). The purpose of the present study was to investigate the minimum effective local anesthetic volume of 0.5% bupivacaine for postoperative analgesia with an anterior suprascapular nerve block (ASSB). The secondary aim was to investigate diaphragm functions with the local anesthetic doses used while conducting effective volume research. Method This prospective observational study was conducted at the American Hospital of Istanbul, Turkey, from March to July 2022. The initial injected volume of 0.5% bupivacaine was 10 ml. Our clinical experience indicates that this yields a complete sensory block of the anterior suprascapular nerve. In accordance with the up-and-down method, the volume of 0.5% bupivacaine used for a particular patient was determined by the outcome of the preceding block, which represented block success. In case of effective ASSB being achieved, the volume of 0.5% bupivacaine to be administered to the next patient was lowered by 1 ml. In case of block failure, however, the volume of 0.5% bupivacaine to be applied in the subsequent case was increased by 1 ml. Ipsilateral hemi-diaphragmatic movement measurements were taken before (baseline) and 30 minutes after the block. General anesthesia was induced 60 minutes after the completion of the block performance by means of a standardized protocol. Results Sixty-seven patients were included in the study. The ED50 and ED95 calculated for anterior suprascapular nerve block using probit transformation and logistic regression analysis were 2.646 (95% CI, 0.877-2.890) and 3.043 ml (95% CI, 2.771-4.065), respectively. When complete paralysis was defined as 75% or above, partial paralysis as 25-50%, and no paralysis as 25% or less, volumes of 6 ml or lower appeared to cause no paralysis for the anterior suprascapular nerve block. Conclusion We, therefore, recommend using a volume of 6 ml or less in order to achieve diaphragm-sparing features for anterior suprascapular nerve blocks.

Acute Extremity Compartment Syndrome and (Regional): Anesthesia: The Monster Under the Bed

Acute compartment syndrome (ACS) is a potential orthopedic emergency that leads, without prompt diagnosis and immediate treatment with surgical fasciotomy, to permanent disability. The role of regional anesthesia (RA) for analgesia in patients at risk for ACS remains unjustifiably controversial. This critical review aims to improve the perception of the published literature to answer the question, whether RA techniques actually delay or may even help to hasten the diagnosis of ACS. According to literature, peripheral RA alone does not delay ACS diagnosis and surgical treatment. Only in 4 clinical cases, epidural analgesia was associated with delayed ACS diagnosis.

The median effective analgesic concentration of ropivacaine in ultrasound-guided interscalene brachial plexus block after arthroscopic rotator cuff repair

Background: The median effective analgesic concentration (MEAC) of ropivacaine in interscalene brachial plexus block (ISBPB) for postoperative analgesia after arthroscopic rotator cuff repair (ARCR) has not been determined. Therefore, this study aimed to evaluate the MEAC after ARCR using 10 ml ropivacaine.

Method: This study was conducted on 40 patients with American Society of Anesthesiologists grade I or II who had selective ARCR. The 10 ml ropivacaine was administered for determined, with an initial concentration of 0.3% using up-and-down sequential allocation. After successful or unsuccessful postoperative analgesia, the concentration of ropivacaine was decreased or increased by 0.05% in the next patient. We defined successful postoperative analgesia as a visual analog scale score of <4 at rest within the initial 8 h after ISBPB. The analytic techniques of linear, linear-logarithmic, exponential regressions and centered isotonic regression were used for calculating MEAC. The secondary outcomes was sufentanil consumption, time to 1st rescue analgesic, onset time of sensory block and motor block.

Results: The concentration of ropivacaine administered ranged from 0.1% to 0.35%. The MEAC from the four different methods (linear, linear-logarithmic, exponential regressions and centered isotonic regression) were 0.207% (95% CI, 0.168–0.355%), 0.182% (95% CI, 0.165–0.353%), 0.196% (95% CI, 0.154–0.356%), and 0.163%, respectively. Of the four models, exponential regression had the least residual standard error (0.0990).

Conclusion: The MEAC derived from the four statistical models for 10 ml ropivacaine in ultrasound-guided ISBPB for postoperative analgesia was distributed within a narrow range of 0.163%–0.207%. The exponential regression model calculated by the goodness-of-fit test at a concentration of 0.196% best fits the study data.

Clinical Trial Registration:http://www.chictr.org.cn/showproj.aspx?proj=127449, identifier ChiCTR2100047978

Median Effective Analgesic Concentration of Ropivacaine in Ultrasound-Guided Interscalene Brachial Plexus Block as a Postoperative Analgesia for Proximal Humerus Fracture: A Prospective Double-Blind Up-Down Concentration-Finding Study

Background

The innervation of the proximal humerus fracture is complicated and unclear. The use of interscalene nerve block has been effective as postoperative analgesia for patients, but the optimal concentration of usage is unknown.

Method

This study was conducted on 30 patients with ASA I or II, who were planning to undergo a proximal humerus fracture operation. A dosage of 10 ml Ropivacaine was administered for the interscalene brachial plexus block (ISBPB) as determined using the up-and-down sequential method. The initial concentration of Ropivacaine in the first patient to receive ISBPB was 0.3%. After a successful or unsuccessful postoperative analgesia, the concentration of local anesthetic was decreased or increased, respectively, by 0.05% in the next patient. We defined successful postoperative analgesia as a visual analog scale (VAS) score of < 4 at rest, within the initial 8 h after ISBPB. The analytic techniques of linear, linear-logarithmic, exponential regressions, and centered isotonic regression were used to determine the EC50 of Ropivacaine, and the residual standard errors were calculated for the comparison of “goodness of fit.”

Results

The concentration of Ropivacaine ranged from 0.1 to 0.35%. The EC50 (95% confidence interval) from 4 different statistical approaches (linear, linear-logarithmic, exponential regressions, and centered isotonic regression) were 0.222% (0.198%, 0.335%), 0.233% (0.215%, 0.453%), 0.223% (0.202%, 0.436%), and 0.232%, respectively. Among all the 4 models, the linear regression had the least residual standard error (0.1676).

Conclusion

The EC50 from the four statistical models for 10 ml Ropivacaine in ultrasound-guided ISBPB for postoperative analgesia was distributed in a narrow range of 0.222–0.233%.

Trial Registration

www.chictr.org.cn/; registration number: ChiCTR2100047231.

Comparing liposomal bupivacaine plus bupivacaine to bupivacaine alone in interscalene blocks for rotator cuff repair surgery: a randomized clinical trial

Background

Single-injection interscalene brachial plexus blocks are used for analgesia for rotator cuff repair (RCR) but have limited duration. The value of adding liposomal bupivacaine (LB) to prolong single-injection interscalene blocks is unclear. The purpose of this trial is to evaluate the addition of LB to regular bupivacaine interscalene blocks for patients undergoing arthroscopic RCR.

Methods

In this prospective, randomized trial, 70 patients undergoing primary RCR with equal group allocation were randomized by random number generator to receive an interscalene block with 20 mL of 0.5% bupivacaine or 10 mL 0.5% bupivacaine plus 133 mg LB. The primary outcome was cumulative opioid consumption within 72 hours of the procedure. Secondary outcomes included maximum pain scores and quality of recovery 15 survey scores.

Results

70 of the 80 randomized patients were included in final analysis following exclusion for protocol violations and loss to follow-up. Cumulative opioid consumption (oral morphine equivalents) within 72 hours in patients receiving LB was a median (IQR) of 31.9 mg (0, 73.1) compared with 45.0 mg (15.0, 108.8) among patients receiving bupivacaine alone (p=0.312). Patients receiving LB demonstrated mixed results regarding worst pain scores with improvements at 24 hours and 72 hours, but not 48 hours.

Conclusions

LB added to bupivacaine interscalene blocks does not reduce opioid consumption within 72 hours following arthroscopic RCR.

Trial registration number

NCT03587584.

Ultrasound-guided peripheral trunk block technique: A new approach gradually stepping onto the stage of clinical anesthesia

In recent years, with the continuous development and validation of new visualization, the ultrasound-guided peripheral trunk block becomes more mature and has a more extensive and broader implementation scope in clinical anesthesia. Based on this, we reviewed and summarized the literature on peripheral trunk nerve block include: paraspinal block, retrolaminar block, plane block of erect spinal muscle, transverse convex to pleural midpoint block, block of the trapezius muscle and anterior serratus muscle, anterior serratus muscle block, thoracic nerve block, abdominal transverse fascia block, type-I block of quadratus lumborum, type-II block of quadratus lumborum, type-III block of quadratus lumborum, block of the sheath of rectus abdominis. This paper reviews the ultrasound-guided peripheral trunk block technique, including development history, anatomic basis, implementation methods, advantages and disadvantages of nerve block technique, and describes the bottleneck and difficulties of nerve block technique at present.

Local anesthetic volume in ultrasound-guided interscalene block and opioid consumption during shoulder arthroscopic surgery: A retrospective comparative study

Interscalene block (ISB) is commonly performed for regional anesthesia in shoulder surgery. Ultrasound-guided ISB enables visualization of the local anesthetic spread and a reduction in local anesthetic volume. However, little is known about the appropriate local anesthetic dose for surgical anesthesia without sedation or general anesthesia. The purpose of our study was to evaluate the appropriate local anesthetic volume by comparing intraoperative analgesics and hemodynamic changes in ISB in arthroscopic shoulder surgery.Overall, 1007 patients were divided into groups 1, 2, and 3 according to the following volume of local anesthetics: 10-19, 20-29, and 30-40 mL, respectively. The use of intraoperative analgesics and sedatives, and the reduction in intraoperative maximum blood pressure and heart rate were compared through retrospective analysis.Fentanyl was used in 55.6% of patients in group 1, which was significantly higher than in those groups 2 and 3 (22.3% and 30.7%, respectively); furthermore, it was also higher than those in groups 2 and 3 in dose-specific comparisons (P < .05). The percent of the maximum reduction in intraoperative systolic blood pressure and heart rate in group 3 was significantly higher than those in groups 1 and 2. Ephedrine administration was lower in group 2 than that in other groups (P < .05). The incidence of hypotensive bradycardic events was lowest (9.1%) at the local anesthetic volume of 24 mL as revealed by the quadratic regression analysis (R2 = 0.313, P = .003).Decreasing the local anesthetic volume to less than 20 mL for ultrasound-guided ISB as the sole anesthesia increases the opioid consumption during shoulder arthroscopic surgery. Local anesthetics >30 mL or increased opioid consumption with <20 mL of local anesthetics could increase the risk of cardiovascular instability intraoperatively. Our findings indicate that 24 mL of local anesthetic could be used to lower the incidence of hypotensive bradycardic events.

Triple Monitoring May Avoid Intraneural Injection during Interscalene Brachial Plexus Block for Arthroscopic Shoulder Surgery: A Prospective Preliminary Study

Nerve injury is a feared complication of peripheral nerve blockade. The aim of this study was to test the effectiveness of a triple monitoring (TM), i.e., a combination of ultrasound (US), nerve stimulation (NS) and opening injection pressure (OIP) during interscalene brachial plexus block (IBPB) for surgery of the shoulder. Sixty patients undergoing IBPB for shoulder arthroscopy received TM. BSmart^®, an inline injection device connected to a 10 mL syringe, was used to detect OIP during IBPB. Nerve stimulation was set to 0.5 mA to rule out any motor response, and if OIP was below 15 PSI, 10 mL of local anaesthetic was injected under US guidance between the C5 and C6 roots. The main outcome was the ability of TM to detect a needle–nerve contact. Other outcomes including the duration of IBPB; pain during injection; postoperative neurologic dysfunction. Triple monitoring revealed needle–nerve contact in 33 patients (55%). In 18 patients, NS evoked motor responses despite first control with US; in a further 15 patients, BSmart^® detected an OIP higher than 15 PSI, despite the absence of motor response to NS. Mean duration of IBPB was 67.2 ± 5.3 seconds; neither pain during injection nor postoperative neurologic dysfunctions were detected. Clinical follow up excluded the presence of postoperative neuropathies. Triple monitoring showed to be a useful and feasible tool while performing IBPB for arthroscopic shoulder surgery. Future studies will be needed to confirm our findings.

Dexmedetomidine combined with suprascapular nerve block and axillary nerve block has a synergistic effect on relieving postoperative pain after arthroscopic rotator cuff repair

PURPOSE

Suprascapular nerve block (SSNB) is the most commonly used block for the relief of postoperative pain from arthroscopic rotator cuff repair and can be used in combination with axillary nerve block (ANB). Dexmedetomidine (DEX) is a type of alpha agonist that can elongate the duration of regional block. The aim of this study was to compare the effects of the use of dexmedetomidine combined with SSNB and ANB with those of the use of SSNB and ANB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 h after arthroscopic rotator cuff repair.

METHODS

Forty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single-center, double-blinded randomized controlled trial study. Twenty patients were randomly allocated to group 1 and received ultrasound-guided SSNB and ANB using a mixture of 0.5 ml (50 μg) of DEX and 9.5 ml of 0.75% ropivacaine preemptively. The other 20 patients were allocated to group 2 and underwent ultrasound-guided SSNB and ANB alone using a mixture of 0.5 ml of normal saline and 9.5 ml of ropivacaine. The visual analog scale (VAS) for pain and patient satisfaction (SAT) scores were postoperatively checked within 48 h. The plasma interleukin (IL)-6, IL-8, IL-1β, cortisol, and serotonin levels were also postoperatively measured within 48 h.

RESULTS

Group 1 showed a significantly lower mean VAS (visual analog scale of pain) score 1, 3, 6, 12, 18 and 24 h after operation, and a significantly higher mean SAT (patient satisfaction) score 1, 3, 6, 12, 18, 24 and 36 h after the operation than group 2. Group 1 showed a significantly lower mean plasma IL-8 level 1 and 48 h after the operation, and a significantly lower mean IL-1β level 48 h after the operation than group 2. Group 1 showed a significantly lower mean plasma serotonin level 12 h after the operation than group 2. The mean timing of rebound pain in group 1 was significantly later than that in group 2 (36 h > 23 h, p = 0.007). Six patients each in groups 1 and 2 showed rebound pain. The others did not show rebound pain.

CONCLUSIONS

Ultrasound-guided SSNA and ANB with DEX during arthroscopic rotator cuff repair resulted in a significantly lower mean VAS score and a significantly higher mean SAT score within 48 h after the operation than SSNB and ANB alone. Additionally, SSNB and ANB with DEX tended to result in a later mean timing of rebound pain accompanied by significant changes in IL-8, IL-1β, and serotonin levels within 48 h after the operation. The present study could provide the basis for selecting objective parameters of postoperative pain in deciding the optimal use of medication for relieving pain.

LEVEL OF EVIDENCE

Level I.

TRIAL REGISTRATION

2015-20, ClinicalTrials.gov Identifier: NCT04398589.

IRB NUMBER

2015-20, Hallym University Chuncheon Sacred Heart Hospital.

Ultrasound-Guided Comparison of Psoas Compartment Block and Supra-Inguinal Fascia Iliaca Compartment Block for Pain Management in Pediatric Developmental Dysplasia of Hip Surgeries

BACKGROUND

The aim of this study was to compare psoas compartment block (PCB) and supra-inguinal fascia iliaca compartment block (SFIB) in terms of pain management and the need for additional systemic analgesia in the perioperative phase of developmental dysplasia of the hip (DDH).

MATERIALS AND METHODS

Sixty pediatric patients were randomized into the PCB group and the SFIB group. The Numeric Rating Scale (NRS) pain scores were used to assess postoperative pain during the initial 24 h after extubation. Sufentanil consumption, patient-controlled analgesia (PCA) demands, and complications were also recorded.

RESULTS

The NRS pain scores were significantly lower in the PCB group than in the SFIB group at 0, 4, 8, 12, and 24 h after extubation (all P < 0.01). Postoperatively, 13.8% of patients in the PCB cohort received additional administration of sufentanil, in contrast to 63.3% of the SFIB cohort (P < 0.01). In the PCB group, 0 (0-0) mcg/kg sufentanil was administered, while in the SFIB group 0.1 (0-0.2) mcg/kg (P < 0.01). In addition, the PCB group had fewer PCA demands than the SFIB group within the initial 24 h (P < 0.01). It took less operating time to achieve SFIB as compared to PCB (P < 0.01). No adverse events related to two techniques were recorded.

CONCLUSIONS

PCB provided a better perioperative pain management in pediatric patients with the DDH surgeries compared to SFIB. It also reduced the need for supplementary systemic analgesia.

Low-volume C5–6 interscalene and supraclavicular nerve blocks for arthroscopic shoulder surgery: A case series

Interscalene block (ISB) is considered a gold standard regional anesthesia technique for shoulder surgery. Conventionally, 20 ml of local anesthetic is used for ISB. Nevertheless, this high-volume traditional ISB is associated with a high incidence of hemidiaphragmatic paresis due to phrenic nerve block. Recent evidence suggests that low-volume ultrasound-guided (USG)-ISB can provide effective analgesia whilst avoiding complications. Thirty patients of American Society of Anaesthesiologist ASA status I/II undergoing arthroscopic rotator cuff repair surgery under general anesthesia were administered low-volume USG-ISB and supraclavicular nerve block (SCNB). The block provided effective analgesia in 90% (27/30) of the patients as their visual analog score was below 4 at all times in the 24-h postoperative period. Only three patients required a single dose of rescue analgesic (diclofenac 50 mg iv) in the 24-h postoperative period. In postoperative recovery, two patients (6.67%) had desaturation due to hemidiaphragmatic paresis and three patients (10%) had a transient neurological deficit. In conclusion, low-volume USG-ISB with SCNB provides effective analgesia for arthroscopic rotator cuff repair surgery. The advantages of this technique include a low incidence of respiratory and neurological complications.

Minimum Effective Volume of 0.75% Ropivacaine for Ultrasound-Guided Axillary Brachial Plexus Block

Background

Ultrasound-guided peripheral nerve block provides direct visualization of nerve and reduces the complications associated with classical landmark guided technique, by reducing the dosage of local anesthetic drugs. This study aims to determine the minimum effective volume (MEAV) of 0.75% ropivacaine for ultrasound-guided axillary brachial plexus block.

Methodology

A total of 23 patients of age group 18-75 years belonging to ASA grade 1, 2, and 3 were selected based on inclusion criteria. The MEAV was determined by using Dixons & Massey Step-up and Step-down method. The initial volume was selected as 15 mL based on previous studies. Depending on block success or failure, 1 mL of the drug was decreased or increased. Block was assessed in terms of motor and sensory components. The study was aborted after attaining five cases of block failure, followed by five cases of a successful block.

Results

The MEAV to be given for a successful block in 50% of patients (MEAV50) was 8.62 mL (95%CI 3.54-9.89). The MEAV to be given for a successful block in 90% of patients (MEAV 90) was 11.82 mL (95% CI 9.9-75.7).

Conclusion

 Ultrasound guidance reduces the dosage of local anesthetic drugs to be used and provides surgical anesthesia without any complications or adverse effects.

A comparison of ice wrap and subacromial injection for postoperative pain and edema control following arthroscopic rotator cuff repair

Background

Postoperative pain and edema are the most common problems associated with arthroscopic rotator cuff repair. The purpose of the present study was to compare ice wrap and subacromial injection (SI) as treatments for early postop pain and edema control and to contrast them with a control group.

Materials and methods

59 patients treated with arthroscopic rotator cuff repair were randomized into three groups: 23 patients who received an ice wrap, 20 patients who received a SI, and a control group of 16 patients.

Results

Patient demographics, comorbidities, tear retraction, degree of fatty muscle degeneration, surgical procedures, and amount of irrigation fluid were similar for the three groups, which also showed similar results regarding postoperative pain and edema control as well as analgesic consumption.

Conclusions

The present study failed to show any difference in effectiveness between the two most common pain management modalities, or between those modalities and the control group.

Level of evidence

IV, prospective observational study.

Comparison of ultrasound-guided and nerve stimulator-guided interscalene blocks as a sole anesthesia in shoulder arthroscopic rotator cuff repair: A retrospective study

Ultrasound-guided interscalene block (US-ISB) and nerve stimulator-guided interscalene block (NS-ISB) have both been commonly used for anesthesia in shoulder arthroscopic surgery.This study aims to compare which method provides surgical block as a sole anesthesia. In this retrospective study, 1158 patients who underwent shoulder arthroscopic rotator cuff tear repair surgery under ISB between October 2002 and March 2018 were classified into either the US-ISB or NS-ISB anesthesia groups. Demographic and anesthetic characteristics and intraoperative medications were analyzed after propensity score matching and compared between the 2 groups.There was a 0.5% rate of conversion to general anesthesia in the US-ISB group and a 6.7% rate in the NS-ISB group (P < .001). The volume of local anesthetics used for ISB was 29.7 ± 8.9 mL in the US-ISB group versus 38.1 ± 4.8 mL in the NS-ISB group (P < .001). The intraoperative use of analgesics and sedatives such as fentanyl, midazolam and propofol in combination was significantly lowered in the US-ISB group (P < .001).US-ISB is a more effective and safer approach for providing intense block to NS-ISB because it can decrease the incidence of conversion to general anesthesia and reduce the use of analgesics and sedatives during arthroscopic shoulder surgery.

Dexmedetomidine combined with interscalene brachial plexus block has a synergistic effect on relieving postoperative pain after arthroscopic rotator cuff repair

PURPOSE

Interscalene brachial plexus block (ISB) is one of the most commonly used regional blocks in relieving postoperative pain after arthroscopic rotator cuff repair. Dexmedetomidine (DEX) is an alpha 2 agonist that can enhance the effect of regional blocks. The aim of this study was to compare the effects of DEX combined with ISB with ISB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 h after arthroscopic rotator cuff repair.

METHODS

Fifty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single center, double-blinded randomized controlled trial study. Twenty-five patients were randomly allocated to group 1 and received ultrasound-guided ISB using a mixture of 1 ml (100 μg) of DEX and 8 ml of 0.75% ropivacaine preemptively. The other 25 patients were allocated to group 2 and underwent ultrasound-guided ISB alone using a mixture of 1 ml of normal saline and 8 ml of ropivacaine. The visual analog scale (VAS) for pain and patient satisfaction (SAT) scores were checked within 48 h postoperatively. The plasma interleukin (IL)-6, -8, -1β, cortisol, and substance P levels were also measured within 48 h, postoperatively.

RESULTS

Group 1 showed a significantly lower mean VAS score and a significantly higher mean SAT score than group 2 at 1, 3, 6, 12, and 18 h postoperatively. Compared with group 2, group 1 showed a significantly lower mean plasma IL-6 level at 1, 6, 12, and 48 h postoperatively and a significantly lower mean IL-8 level at 1, 6, 12, 24, and 48 h postoperatively. The mean timing of rebound pain in group 1 was significantly later than that in group 2 (12.7 h > 9.4 h, p = 0.006).

CONCLUSIONS

Ultrasound-guided ISB with DEX in arthroscopic rotator cuff repair led to a significantly lower mean VAS score and a significantly higher mean SAT score within 48 h postoperatively than ISB alone. In addition, ISB with DEX showed lower mean plasma IL-6 and IL-8 levels than ISB alone within 48 h postoperatively, with delayed rebound pain.

LEVEL OF EVIDENCE

I.

TRIAL REGISTRATION

2013-112, ClinicalTrials.gov Identifier: NCT02766556.

Truncal injection brachial plexus block: A Description of a novel injection technique and dose finding study

Background and Aims

Brachial plexus (BP) blocks continue to be described with reference to anatomical landmarks (Interscalene and Supraclavicular), even after the introduction of ultrasound which enables us to directly identify the roots, trunks and divisions of the BP. The aim of this study was to describe a novel injection technique targeting trunks of BP and to determine the minimum effective local anaesthetic volume (MELAV) required to produce BP block with this approach.

Methods

Twenty-one male patients in the age group 20-40 years, undergoing elective forearm bony procedures received an ultrasound-guided truncal injection BP block. MELAV₅₀ was determined using the Dixon and Mood up-and-down method. Initial volume of local anaesthetic (LA; 50:50 mixture of bupivacaine 0.5% and lignocaine 2% with 5 μg/ml epinephrine) injected was 6 ml in each trunk, which was varied by 1 ml/trunk for each consecutive patient according to the response of the previous patient. The MELAV₅₀, MELAV₉₅ and MELAV₉₉ were calculated using Probit transformation and logistic regression.

Results

Out of the 21 patients, 13 patients had a successful block. The MELAV₅₀, MELAV₉₅ and MELAV₉₉ were 7.41, 10.47 and 12 ml, respectively. Eight patients in whom block failed had sparing in the ulnar and median nerve territories.

Conclusion

Trunks of the brachial plexus can be identified and targeted for the injection of local anaesthetics. The MELAV₅₀ and MELAV₉₅ required for ultrasound-guided truncal injection brachial plexus block were 7.4 and 10.4 ml, respectively.

A fluoroscopic assessment of brachial plexus block by the supraclavicular approach: Have we been overmedicating?

Background

Ultrasonography-guided supraclavicular brachial plexus block has demonstrated safety as compared with landmark or nerve stimulation techniques. However, the minimum effective analgesic volume (MEAV) necessary for adequate blockade has not been determined. This study was undertaken to assess under fluoroscopy the postinjection spread of different drug volumes with clinical correlation. Secondary outcome measures included correlation of onset of block, block quality, and incidence of side effects.

Methods

This randomized, multiarm, cross-sectional, observational study was conducted at a single tertiary care center. A total of 549 patients were randomly allocated to 3 groups (20 ml, 30 ml, and 40 ml of drug mixture). A local anesthetic drug mixture with a radiopaque dye was administered under ultrasonographic guidance, and postinjection fluoroscopic drug spread was studied.

Results

Surgical anesthesia was achieved in 494 (89.98%) patients with 85.25%, 92.97%, and 91.71% in 20-, 30-, and 40-ml groups, respectively, being significantly low (p = 0.0317) in the 20-mL group. Cephalad and infraclavicular spread was higher in the 40-mL group than in other two groups (p = 0.103). Horner syndrome (HS) was seen in 51.18% of patients. First, ipsilateral superficial cervical plexus block was also observed in 40.22% of patients. Among patients who developed both, ∼60% of patients (99/167) belonged to the 40-mL group.

Conclusions

Optimal MEAV appears between 20 and 30 mL. Higher drug volumes are associated with more cephalad spread and side effects. Drug spread can predict block efficacy as well. It is postulated that loss of sensation in the ipsilateral neck can be used to predict development of hemidiaphragmatic paresis similar to HS.

Retrospective Analysis of Ultrasound-Guided Infraclavicular Block: Effect of Experience of Anesthesiologists on Volume of Local Anesthetic Administered

Performing a block under ultrasound guidance effectively requires skill; however, inexperienced anesthesiologists often use high-dose LA to ensure success. We aimed to share our experience with the ultrasound-guided infraclavicular brachial plexus block (USGICB) for upper extremity surgeries and to determine changes in failure rate and local anesthetic dose administered with gaining adequate experience. With approval from the local ethics committee, a retrospective review of records of 2953 patients who underwent USGICB between November 2011 and March 2015 was performed for evaluating the following data: age, sex, height, weight, operation type, American Society of Anesthesiologists physical status score, local anesthetic volume, complications, and success of USGICB. The patients were divided into 4 groups of 10 months each from November 2011 to March 2015: first 10-month period, 628 cases (group I); second 10-month period, 672 (group II); third 10-month period, 720 (group III); and the fourth 10-month period, 933 cases (group IV). Nine anesthesiologists with the same baseline experience in USG performed the blocks. During the initial period, when anesthesiologists had insufficient experience, local anesthetic (LA) dose, success rate, failed blocks, and complications were investigated. The LA volume administered in group I (33.7 ± 4.2 ml) was significantly higher than that in groups II, III, and IV (p < 0.05). Although a reduction in LA volume administered with increasing anesthesiologist experience was not statistically significant, a volume reduction of over 30 ml was observed in groups II, III, and IV compared with group I. Furthermore, in group I, failure rate (3.2%) was higher than that in groups II, III, and IV (p < 0.05). We concluded that sonographic guidance ensures a high success rate and that increased experience of anesthesiologists is associated with reduced complications and failure rate of blocks, in addition to prevention of LA overdose.

Diaphragm-sparing effect of the infraclavicular subomohyoid block vs low volume interscalene block. A randomized blinded study

BACKGROUND

Both low volume interscalene and infraclavicular-subomohyoid blocks were suggested to provide shoulder analgesia with low risk of phrenic nerve block. The aim of this study was to compare the frequency of the phrenic nerve block between these two techniques.

METHOD

Seventy-two patients scheduled for shoulder arthroscopy were included in this randomized controlled blind study. Before induction of general anesthesia, patients received low volume interscalene block using 5 mL of ropivacaine 0.5% (LVS group) or infraclavicular-subomohyoid block using 25 mL of ropivacaine 0.5% (ISO group). The diaphragmatic excursion was measured (using ultrasound) before the block and after surgery. If the ratio of postoperative to pre-block excursions was <25%, a phrenic nerve block was concluded. Secondary outcomes were: the duration of analgesia, the 24-hour morphine requirement, and patient satisfaction.

RESULTS

The phrenic nerve was blocked in 88.9% of patients in LVS group vs 5.6% in ISO group (P < 0.001). There was no significant difference between the two groups with regard to the duration of analgesia, the morphine consumption, and the patient satisfaction.

CONCLUSION

Compared with the low volume interscalene block, the infraclavicular subomohyoid block resulted in a significantly less frequent phrenic nerve block and with no difference in postoperative analgesia. Therefore, it may be relevant to consider for patients who cannot tolerate a phrenic nerve block.

Post-operative pain control following arthroscopic rotator cuff repair: peri-articular injection versus interscalene brachial plexus block

PURPOSE

To compare post-operative pain relief with peri-articular injection (PI) versus interscalene brachial plexus block (IBPB) after arthroscopic rotator cuff repair (ARCR) surgery.

METHODS

We retrospectively reviewed 121 consecutive patients undergoing ARCR surgery divided into two groups: the PI group and the IBPB group. We compared complications and self-reported pain score measured using a Numerical Rating Scale (NRS) during the initial 24 hours after surgery.

RESULTS

The NRS scores recorded in the recovery room (0), 0.5, and four hours post-operatively were higher in the PI group (n = 38) than the IBPB group (n = 52) (2.1 vs. 0.8, p = 0.014; 1.4 vs. 0.5, p = 0.0069; and 1.3 vs. 0.5, p = 0.012, respectively). However, the NRS scores recorded at 16, 20, and 24 hours post-operatively were lower in the PI group than in the IBPB group (1.4 vs. 3.1, p < 0.0001; 1.4 vs. 3.2, p < 0.0001; and 1.7 vs. 3.2, p = 0.00046, respectively). The incidences of post-operative nausea and temporary numbness in the upper arm were significantly lower in the PI group than in the IBPB group (7.9% vs. 33%, p = 0.0052; and 13% vs. 85%, p < 0.0001, respectively).

CONCLUSIONS

Although IBPB provided superior pain control during the initial few hours after ARCR surgery, PI was superior from 16 to 24 hours post-operatively. The rates of side effects, such as nausea and temporary arm numbness, were also lower in the PI group than in the IBPB group.

Ultrasound-Guided Combined Interscalene-Cervical Plexus Block for Surgical Anesthesia in Clavicular Fractures: A Retrospective Observational Study

Objective

We aim to report our experiences regarding the implementation of the ultrasound-guided combined interscalene-cervical plexus block (CISCB) technique as a sole anesthesia method in clavicular fracture repair surgery.

Materials and Methods

Charts of patients, who underwent clavicular fracture surgery through this technique, were reviewed retrospectively. We used an in-plane ultrasound-guided single-insertion, double-injection combined interscalene-cervical plexus block technique. During the performance of each block, the block areas were visualized by using a linear transducer, and the needles were advanced by using the in-plane technique. Block success and complication rates were evaluated.

Results and Discussion

12 patients underwent clavicular fracture surgery. Surgical regional anesthesia was achieved in 100% of blocks. None of the patients necessitated conversion to general anesthesia during surgery. There were no occurrences of acute complications.

Conclusions

The ultrasound-guided combined interscalene-cervical plexus block was a successful and effective regional anesthesia method in clavicular fracture repair. Prospective comparative studies would report the superiority of the regional technique over general anesthesia.

Ultrasound-Guided Interscalene Catheter Complicated by Persistent Phrenic Nerve Palsy

A 76-year-old male presented for reverse total shoulder arthroplasty (TSA) in the beach chair position. A preoperative interscalene nerve catheter was placed under direct ultrasound-guidance utilizing a posterior in-plane approach. On POD 2, the catheter was removed. Three weeks postoperatively, the patient reported worsening dyspnea with a subsequent chest X-ray demonstrating an elevated right hemidiaphragm. Pulmonary function testing revealed worsening deficit from presurgical values consistent with phrenic nerve palsy. The patient decided to continue conservative management and declined further invasive testing or treatment. He was followed for one year postoperatively with moderate improvement of his exertional dyspnea over that period of time. The close proximity of the phrenic nerve to the brachial plexus in combination with its frequent anatomical variation can lead to unintentional mechanical trauma, intraneural injection, or chemical injury during performance of ISB. The only previously identified risk factor for PPNP is cervical degenerative disc disease. Although PPNP has been reported following TSA in the beach chair position without the presence of a nerve block, it is typically presumed as a complication of the interscalene block. Previously published case reports and case series of PPNP complicating ISBs all describe nerve blocks performed with either paresthesia technique or localization with nerve stimulation. We report a case of a patient experiencing PPNP following an ultrasound-guided placement of an interscalene nerve catheter.

A randomized trial of automated intermittent ropivacaine administration vs. continuous infusion in an interscalene catheter

BACKGROUND

Ultrasound-guided interscalene nerve block with ropivacaine as local anesthetic agent given as boluses or continuous infusion is the preferred pain management after major shoulder surgery. The use of automated intermittent boluses has been shown to be superior to continuous infusion in sciatic and epidural nerve block.

HYPOTHESIS

Automated intermittent boluses reduce pain after major shoulder surgery.

METHODS

Seventy patients aged 18-75 years, scheduled for major shoulder surgery under general anesthesia with interscalene nerve block were included in this randomized controlled trial. Patients were allocated to either automated intermittent boluses with 16 mg ropivacaine every 2 h combined with patient-controlled administration or to a conventional regimen of continuous infusion of 8 mg/h (4 ml/h) of ropivacaine combined with patient controlled administration (2 ml, lockout time 30 min). Pain (Visual Analog Scale, VAS) was assessed every 8 h postoperatively.

RESULTS

Fifty-seven patients completed the study, 29 in the continuous infusion group and 28 in the automated intermittent bolus group. Shoulder arthroplasty was performed in 49 (86%) of the cases. There were no significant differences in VAS score from 8 to 48 h post-operatively. No significant difference in opioid usage was observed. The automated intermittent bolus group reported significantly less force on coughing and more hoarseness. A significantly lower volume of ropivacaine was used in the automated intermittent bolus group.

CONCLUSION

Automated intermittent boluses did not reduce pain or rescue opioid consumption compared with continuous infusion of ropivacaine. The automated intermittent bolus group had significantly less force on coughing and more hoarseness.

Effects of arthroscopy-guided suprascapular nerve block combined with ultrasound-guided interscalene brachial plexus block for arthroscopic rotator cuff repair: a randomized controlled trial

PURPOSE

The aim of this study was to compare the pain relieving effect of ultrasound-guided interscalene brachial plexus block (ISB) combined with arthroscopy-guided suprascapular nerve block (SSNB) with that of ultrasound-guided ISB alone within the first 48 h after arthroscopic rotator cuff repair.

METHODS

Forty-eight patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled. The 24 patients in group 1 received ultrasound-guided ISB and arthroscopy-guided SSNB; the remaining 24 patients in group 2 underwent ultrasound-guided ISB alone. Visual analogue scale pain score and patient satisfaction score were checked at 1, 3, 6, 12, 18, 24, and 48 h post-operatively.

RESULTS

Group 1 had a lower visual analogue scale pain score at 3, 6, 12, 18, 24, and 48 h post-operatively (1.7 < 2.6, 1.6 < 4.0, 3.5 < 5.8, 3.6 < 5.2, 3.2 < 4.2, 1.3 < 2.0), and a higher patient satisfaction score at 6, 12, 18, 24, and 36 h post-operatively than group 2 (7.8 > 6.0, 6.2 > 4.3, 6.4 > 5.1, 6.9 > 5.9, 7.9 > 7.1). Six patients in group 1 developed rebound pain twice, and the others in group 1 developed it once. All of the patients in group 2 had one rebound phenomenon each (p = 0.010). The mean timing of rebound pain in group 1 was later than that in group 2 (15.5 > 9.3 h, p < 0.001), and the mean size of rebound pain was smaller in group 1 than that in group 2 (2.5 > 4.0, p = 0.001).

CONCLUSION

Arthroscopy-guided SSNB combined with ultrasound-guided ISB resulted in lower visual analogue scale pain scores at 3-24 and 48 h post-operatively, and higher patient satisfaction scores at 6-36 h post-operatively with the attenuated rebound pain compared to scores in patients who received ultrasound-guided ISB alone after arthroscopic rotator cuff repair. The combined blocks may relieve post-operative pain more effectively than the single block within 48 h after arthroscopic cuff repair.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I. ClinicalTrials.gov Identifier: NCT02424630.

The minimal effective volume (MEAV 95) for interscalene brachial plexus block for surgical anesthesia under sedation: A prospective observational dose finding study

Background: Interscalene brachial plexus (ISB) block is routinely used to provide anesthesia and analgesia for shoulder surgery. Traditional local anesthetic volumes for ISB result in near universal ipsilateral phrenic nerve paresis potentially including oxygenation and ventilation.

Aims: The purpose of this study was to determine the lowest minimal effective anesthetic volume in 95% of patients (MEAV 95) of ropivacaine 0.75% for ISB that provides surgical anesthesia for arthroscopic shoulder surgery.

Methods: Prospective observational cohort study in patients undergoing arthroscopic shoulder surgery under ISB (C6 level) with sedation. The dose finding protocol used the Narayana rule for up/down sequential allocation to estimate the MEAV 95 of ropivacaine 0.75%. Successful ISB was defined as complete absence of pinprick sensation in the C5 and C6 dermatomes 30 min postblock. Secondary outcomes assessed included ability to complete surgery with propofol sedation, change in slow vital capacity, room air oxygen saturation postblock, block duration, ISB complications, and numeric rating scale for pain immediately after surgery.

Results: The study was stopped early due to futility. Among 225 participants approached, 54 consented to participate. The MEAV 95 for ultrasound-guided ISB of ropivacaine 0.75% for shoulder surgery was unable to be accurately estimated. Local anesthetic volumes between 5 and 20 ml did not influence any of the predefined secondary outcomes.

Conclusions: The MEAV 95 (at 30 min) of ropivacaine 0.75% for ultrasound-guided ISB exceeds the local anesthetic volumes that consistently produces hemidiaphragmatic impairment. ISB cannot be guaranteed to provide surgical anesthesia at 30 min without the potential for concomitant phrenic nerve block.

Paravertebral Block Plus Thoracic Wall Block versus Paravertebral Block Alone for Analgesia of Modified Radical Mastectomy: A Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

Paravertebral block placement was the main anesthetic technique for modified radical mastectomy in our hospital until February 2014, when its combination with blocks targeting the pectoral musculature was initiated. We compared the analgesic effects of paravertebral blocks with or without blocks targeting the pectoral musculature for modified radical mastectomy.

METHODS

We retrospectively collected data from a single surgeon and anesthesiologist from June 1, 2012, to May 31, 2015. Intraoperative sedatives and analgesic requirements, time to the first analgesic request, postoperative analgesic doses, patient satisfaction, and complications were compared.

RESULTS

Fifty-four patients received a paravertebral block alone (PECS 0), and 46 received a paravertebral block combined with blocks targeting the pectoral musculature (PECS 1). The highest intraoperative effect-site concentration of propofol was significantly lower in the PECS 1 group than in the PECS 0 group [2.3 (1.5, 2.8) vs 2.5 (1.5, 4) μg/mL, p = 0.0014]. The intraoperative rescue analgesic dose was significantly lower in the PECS 1 group [0 (0, 25) vs 0 (0, 75) mg of ketamine, p = 0.0384]. Furthermore, the PECS 1 group had a significantly longer time to the first analgesic request [636.5 (15, 720) vs 182.5 (14, 720) min, p = 0.0001]. After further adjustment for age, body mass index, American Society of Anesthesiologists Physical Status classification, chronic pain history, incidence of a superficial cervical plexus block placement, and operation duration, blocks targeting the pectoral musculature were determined to be the only significant factor (hazard ratio, 0.36; 95% confidence interval, 0.23-0.58; p < 0.0001). Very few patients used potent analgesics including morphine and ketorolac; the cumulative use of morphine or ketorolac was similar in the study groups. However, the incidence of all analgesic use, namely morphine, ketorolac, acetaminophen, and celecoxib, was significantly lower in the PECS 1 group [3.5 (0, 6) vs 5 (0, 12), p < 0.0001].

CONCLUSIONS

Compared with the placement of a paravertebral block alone, combining blocks targeting the pectoral musculature with a paravertebral block for modified radical mastectomy reduced the sedative and analgesic requirements during operation and provided more effective postoperative analgesia.

Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection

Background

Interscalene brachial plexus (ISB) block is often associated with phrenic nerve block and diaphragmatic paresis. The goal of our study was to test if the anterior or the posterior ultrasound guided approach of the ISB is associated with a lower incidence of phrenic nerve blocks and impaired lung function.

Methods

This was a prospective, randomized and single-blinded study of 84 patients scheduled for elective shoulder surgery who fullfilled the inclusion and exclusion critereria. Patients were randomized in two groups to receive either the anterior (n = 42) or the posterior (n = 42) approach for ISB. Clinical data were recorded. In both groups patients received ISB with a total injection volume of 15 ml of ropivacaine 1 %. Spirometry was conducted at baseline (T₀) and 30 min (T₃₀) after accomplishing the block.

Changes in spirometrical variables between T₀ and T₃₀ were investigated by Wilcoxon signed-rank test for each puncture approach. The temporal difference between the posterior and the anterior puncture approach groups were again analyzed by the Wilcoxon-Mann-Whitney test.

Results

The spirometric results showed a significant decrease in vital capacity, forced expiratory volume per second, and maximum nasal inspiratory breathing after the Interscalene brachial plexus block; indicating a phrenic nerve block (p <0.001, Wilcoxon signed-rank). A significant difference in the development of the spirometric parameters between the anterior and the posterior group could not be identified (Wilcoxon-Mann-Whitney test). Despite the changes in spirometry, no cases of dyspnea were reported.

Conclusion

A different site of injection (anterior or posterior) did not show an effect in reducing the cervical block spread of the local anesthetic and the incidence of phrenic nerve blocks during during ultrasound guided Interscalene brachial plexus block. Clinical breathing effects of phrenic nerve blocks are, however, usually well compensated, and subjective dyspnea did not occur in our patients.

Trial registration

German Clinical Trials Register (DRKS number 00009908, registered 26 January 2016).

Comparison of tissue distribution, phrenic nerve involvement, and epidural spread in standard- vs low-volume ultrasound-guided interscalene plexus block using contrast magnetic resonance imaging: a randomized, controlled trial

BACKGROUND

Ultrasound guidance allows for the use of much lower volumes of local anaesthetics for nerve blocks, which may be associated with less aberrant spread and fewer complications. This randomized, controlled study used contrast magnetic resonance imaging to view the differential-volume local anaesthetic distribution, and compared analgesic efficacy and respiratory impairment.

METHODS

Thirty patients undergoing shoulder surgery were randomized to receive ultrasound-guided interscalene block by a single, blinded operator with injection of ropivacaine 0.75% (either 20 or 5 ml) plus the contrast dye gadopentetate dimeglumine, followed by magnetic resonance imaging. The primary outcome was epidural spread. Secondary outcomes were central non-epidural spread, contralateral epidural spread, spread to the phrenic nerve, spirometry, ultrasound investigation of the diaphragm, block duration, pain scores during the first 24 h, time to first analgesic consumption, and total analgesic consumption.

RESULTS

All blocks provided fast onset and adequate intra- and postoperative analgesia, with no significant differences in pain scores at any time point. Epidural spread occurred in two subjects of each group (13.3%); however, spread to the intervertebral foramen and phrenic nerve and extensive i.m. local anaesthetic deposition were significantly more frequent in the 20 ml group. Diaphragmatic paralysis occurred twice as frequently (n=8 vs 4), and changes from baseline peak respiratory flow rate were larger [Δ=-2.66 (1.99 sd) vs -1.69 (2.0 sd) l min(-1)] in the 20 ml group.

CONCLUSIONS

This study demonstrates that interscalene block is associated with epidural spread irrespective of injection volume; however, less central (foraminal) and aberrant spread after low-volume injection may be associated with a more favourable risk profile.

CLINICAL TRIAL REGISTRATION

This study was registered with the European Medicines Agency (Eudra-CT number 2013-004219-36) and with the US National Institutes' of Health registry and results base, clinicaltrials.gov (identifier NCT02175069).

Incidence of hemidiaphragmatic paresis after peripheral nerve stimulator versus ultrasound guided interscalene brachial plexus block

Background and Aims:

We compared interscalene brachial plexus block (ISBPB) using peripheral nerve stimulation (PNS) and ultrasound (US) techniques. The primary outcomes were the incidence of hemidiaphragmatic paresis (HDP) and the duration of the block. Secondary outcomes were the block success rate, time to conduct the block, onset of sensory block, and dermatomal spread, postoperative pain by Numeric Rating Scale (NRS), duration of postoperative analgesia and incidence of complications.

Material and Methods:

We conducted a prospective, randomized, and observer-blinded study in 60 patients undergoing shoulder arthroscopy under block plus general anesthesia. ISBPB was performed with 10 ml of 0.5% bupivacaine using either PNS (Group PNS, n = 30) or US (Group US, n = 30). Hemidiaphragmatic function, the primary outcome, was assessed by ultrasonographic evaluation of diaphragmatic movement and pulmonary function tests using a bedside spirometer (forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate). General anesthesia was administered to all the patients for surgery. P < 0.05 test was considered to be statistically significant.

Results:

Twelve patients in Group PNS had HDP and none in Group US (P < 0.0001). PFTs were also significantly reduced in Group PNS (P < 0.0001). The time to conduct the block and sensory onset time both were less in Group US (P < 0.05). The groups did not differ in block success rate, duration of analgesia, and NRS. Other complications like incidence of Horner's syndrome and vascular puncture were comparable in both the groups.

Conclusions:

PNS guided ISBPB with 10 ml of 0.5% bupivacaine is associated with a higher incidence of HDP as compared to US guided ISBPB. There is no significant difference in quality or duration of analgesia in the two groups.

The efficacy of simultaneous bilateral axillary brachial plexus block under the guidance of neurostimulator or ultrasound: a prospective study

PURPOSE

This study was designed to investigate the risk of local anesthetic toxicity and efficacy of simultaneous bilateral axillary brachial plexus block performed under the guidance of ultrasound or a neurostimulator.

METHODS

One hundred and twenty patients who were anesthetized with bilateral axillary plexus block simultaneously between February 2012 and March 2014 were enrolled in the study. The patients were anesthetized under the guidance of a neurostimulator (group N, n = 60) or ultrasound (group U, n = 60). The block performance time, procedure-related pain, adverse events, total and free plasma concentrations of ropivacaine, and other data were recorded. The comparison was analyzed statistically.

RESULTS

The block performance time, and onset of the sensory and motor block, of group N was longer than that of group U (p < 0.001). The procedure-related pain of group N was more serious than that of group U (p < 0.05). The patient satisfaction rate of group U was higher than that of group N (p < 0.05). The total plasma concentrations of ropivacaine in group N were comparable to those of group U, except for the value at 50 min after injection (p < 0.05). The free plasma concentrations of ropivacaine of group N at 5 min were significantly higher than that of group U (p < 0.001). No apparent serious adverse events were observed perioperatively in both groups.

CONCLUSIONS

Simultaneous bilateral axillary brachial plexus block guided by neurostimulator or ultrasound in bilateral distal upper extremity surgery seems to have a low risk of local anesthetic toxicity and to be effective. The ultrasound-guided block is superior in terms of providing the same degree of anesthesia with shorter duration, less pain, and faster onset of sensory and motor blockades, which is important in clinical practice.

Dose-dependency of dexamethasone on the analgesic effect of interscalene block for arthroscopic shoulder surgery using ropivacaine 0.5%: A randomised controlled trial

BACKGROUND

Dexamethasone prolongs the duration of single-shot interscalene brachial plexus block (SISB). However, dose-dependency of dexamethasone as an adjuvant for SISB remains insufficiently understood.

OBJECTIVE

The objective of this study is to evaluate the effect of different doses of dexamethasone on the duration of SISB using ropivacaine 0.5%.

DESIGN

A randomised, double-blind controlled trial.

SETTING

Single university tertiary care centre.

PATIENTS

One hundred and forty-four patients scheduled for elective arthroscopic shoulder surgery were allocated randomly to one of four groups.

INTERVENTIONS

Patients received 12 ml of ropivacaine 0.5% in 0.9% saline (control group), or containing dexamethasone 2.5, 5.0 or 7.5 mg for SISB.

MAIN OUTCOME MEASURES

The primary endpoint was the time to the first analgesic request. Pain scores and adverse effects were also assessed up to 48 h postoperatively.

RESULTS

Inclusion of dexamethasone 2.5, 5.0 and 7.5 mg resulted in significant (P < 0.001) increases in time to the first analgesic request by factors of 1.6, 2.2 and 1.8, respectively. The percentages of patients not requiring analgesics in the first 48 h postoperatively with dexamethasone 0.0, 2.5, 5.0 and 7.5 mg were 3, 22, 39 and 33%, respectively (P < 0.001). There were no significant effects on pain scores or incidences of adverse effects.

CONCLUSION

Dexamethasone demonstrated significant beneficial dose-dependent effects on duration to the first analgesic request, the number of patients not requiring analgesics and analgesic use in the first 48 h after SISB for arthroscopic shoulder surgery. There were no significant effects on pain scores or incidences of adverse effects.

TRIAL REGISTRATION

the trial was registered with the Clinical Trial Registry of Korea: https://cris.nih.go.kr/cris/index.jsp. Identifier: KCT0001078.

Effect of dexamethasone in low volume supraclavicular brachial plexus block: A double-blinded randomized clinical study

BACKGROUND AND AIMS

With the use of ultrasound, a minimal effective volume of 20 ml has been described for supraclavicular brachial plexus block. However achieving a long duration of analgesia with this minimal volume remains a challenge. We aimed to determine the effect of dexamethasone on onset and duration of analgesia in low volume supraclavicular brachial plexus block.

MATERIAL AND METHODS

Sixty patients were randomly divided into two groups of 30 each. Group C received saline (2 ml) + 20 ml of 0.5% bupivacaine and Group D received dexamethasone (8 mg) + 20 ml of 0.5% bupivacaine in supraclavicular brachial plexus block. Hemodynamic variables and visual analog scale (VAS) score were noted at regular intervals until 450 min. The onset and duration of sensory and motor block were measured. The incidence of "Halo" around brachial plexus was observed. Student's t-test and Chi-square test were used for statistical analysis.

RESULTS

The onset of sensory and motor block was significantly earlier in dexamethasone group (10.36 ± 1.99 and 12 ± 1.64) minutes compared to control group (12.9 ± 2.23 and 18.03 ± 2.41) minutes. The duration of sensory and motor block was significantly prolonged in dexamethasone group (366 ± 28.11 and 337.33 ± 28.75) minutes compared to control group (242.66 ± 26.38 and 213 ± 26.80) minutes. The VAS score was significantly lower in dexamethasone group after 210 min. "Halo" was present around the brachial plexus in all patients in both the groups.

CONCLUSION

Dexamethasone addition significantly increases the duration of analgesia in patients receiving low volume supraclavicular brachial plexus block. No significant side-effects were seen in patients receiving dexamethasone as an adjunct.

Comparison of Outside Versus Inside Brachial Plexus Sheath Injection for Ultrasound-Guided Interscalene Nerve Blocks

OBJECTIVES

Ultrasound-guided interscalene brachial plexus blocks are commonly used to provide anesthesia for the shoulder and proximal upper extremity. Some reviews identify a sheath that envelops the brachial plexus as a potential tissue plane target, and current editorials in the literature highlight the need to establish precise and reproducible injection targets under ultrasound guidance. We hypothesize that an injection of a local anesthetic inside the brachial plexus sheath during ultrasound-guided interscalene nerve blocks will result in enhanced procedure success and provide a consistent tissue plane target for this approach with a reproducible and characteristic local anesthetic spread pattern.

METHODS

Sixty patients scheduled for shoulder surgery with a preoperative interscalene block for postoperative pain management were enrolled in this prospective randomized observer-blinded study. Each patient was randomly assigned to receive a single-shot interscalene block either inside or outside the brachial plexus sheath.

RESULTS

The rate of complete motor and sensory blocks of the axillary nerve territory 10 minutes after local anesthetic injection for the inside group was 70% versus 37% for the outside group (P < .05). At all measurement intervals beyond 10 minutes, however, neither group showed a statistically significant difference in complete sensory blockade. The incidence rates of transient paresthesia during needle passage were 6.7% for the outside group and 96.7% for the inside group (P < .05).

CONCLUSIONS

Except for faster onset, this prospective randomized trial did not find any advantages to performing an interscalene block inside the brachial plexus sheath. There was a higher incidence of transient paresthesia when injections were performed inside compared to outside the sheath.

Ultrasound Guided Low Approach Interscalene Brachial Plexus Block for Upper Limb Surgery

Background

The interscalene brachial plexus block is widely used for pain control and anesthetic purposes during shoulder arthroscopic surgeries and surgeries of the upper extremities. However, it is known that interscalene brachial plexus block is not appropriate for upper limb surgeries because it does not affect the lower trunk (C8-T1, ulnar nerve) of the brachial plexus.

Methods

A low approach, ultrasound-guided interscalene brachial plexus block (LISB) was performed on twenty-eight patients undergoing surgery of the upper extremities. The patients were assessed five minutes and fifteen minutes after the block for the degree of block in each nerve and muscle as well as for any complications.

Results

At five minutes and fifteen minutes after the performance of the block, the degree of the block in the ulnar nerve was found to be 2.8 ± 2.6 and 1.1 ± 1.8, respectively, based on a ten-point scale. Motor block occurred in the median nerve after fifteen minutes in 26 of the 28 patients (92.8%), and in all of the other three nerves in all 28 patients. None of the patients received additional analgesics, and none experienced complications.

Conclusions

The present study confirmed the achievement of an appropriate sensory and motor block in the upper extremities, including the ulnar nerve, fifteen minutes after LISB, with no complications.

Lack of Sex Difference in Minimum Local Analgesic Concentration of Ropivacaine for Ultrasound-Guided Supraclavicular Brachial Plexus Block

Background

Sex differences, which may be an important variable for determining anesthetic requirements, have not been well investigated in the aspect of local anesthetic. This investigation aimed to compare the minimum local analgesic concentration (MLAC) of ropivacaine for ultrasound-guided supraclavicular brachial plexus block (US-SCB) between men and women.

Material/Method

Patients aged 18–45 years undergoing elective forearm, wrist, or hand surgeries under US-SCB were divided into 2 groups according to sex. The initial concentration was 0.375% ropivacaine 20 mL and the concentration for the next patient was determined by the up-down technique at 0.025% intervals. Success was defined as the absence of any pain in response to a pinprick in the region of all 4 terminal nerves and the skin incision within 45 min. The primary outcome was the MLAC of ropivacaine, which was estimated by the Dixon and Massey method. The analgesia duration, which was defined as the time from the end of the US-SCB injection to the time of feeling discomfort and need for additional analgesics, was observed for each patient.

Results

The MLAC of ropivacaine 20 mL for US-SCB was 0.2675% (95% confidence interval [CI], 0.2512–0.2838%) in men and 0.2675% (95% CI, 0.2524–0.2826%) in women. There was no significant difference in MLAC or the analgesia duration between the 2 groups (P>0.05).

Conclusions

We found no significant sex-related differences in MLAC or analgesia duration of ropivacaine for US-SCB.