Diaphragm-sparing efficacy of subparaneural upper trunk block for arthroscopic shoulder surgery: A randomised controlled trial

BACKGROUND

Inter-scalene block (ISB) is associated with an inevitable risk of hemi-diaphragmatic paresis (HDP). To reduce the risk of HDP, an upper trunk block (UTB) has been proposed at the brachial plexus division level.

OBJECTIVE

We hypothesised that UTB would be associated with a lower incidence of HDP than ISB while providing sufficient analgesia following arthroscopic shoulder surgery.

DESIGN

Randomised controlled trial.

SETTING

A tertiary teaching hospital.

PATIENTS

Seventy patients aged 20 to 80 years undergoing arthroscopic rotator cuff repair.

INTERVENTION

Ultrasound-guided ISB or UTB was performed with 5 ml 0.75% ropivacaine.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of complete HDP, assessed by diaphragm excursion using ultrasound, defined as a decrease to 25% or less of baseline or occurrence of paradoxical movement. Postoperative pulmonary function change, pain scores, opioid consumption and pain-related outcomes were the secondary outcomes.

RESULTS

The UTB group had a significantly lower incidence of complete HDP than the ISB group [5.9% (2/34) vs. 41.7% (15/36); absolute difference, 35.8%; 95% confidence interval (CI), 17.8 to 53.7%; P  < 0.001]. The postblockade decline in pulmonary function was more pronounced in the ISB group than that in the UTB group. The pain score at 1 h postoperatively was not significantly different between the groups (ISB vs. UTB group: median 0 vs. 1; median difference, -1; 95% CI, -2 to 0.5). No significant difference was observed in any other secondary outcomes.

CONCLUSION

UTB was associated with a lower incidence of HDP compared with ISB while providing excellent analgesia in arthroscopic shoulder surgery.

TRIAL REGISTRATION

Clinical Trial Registry of Korea ( https://cris.nih.go.kr ) identifier: KCT0007002.

IRB NUMBER

Chungnam National University Hospital Institutional Review Board No. 2021-12-069.

Superior Trunk Block Is an Effective Phrenic-Sparing Alternative to Interscalene Block for Shoulder Arthroscopy: A Systematic Review and Meta-Analysis

The interscalene block (ISB) is the standard regional anesthesia for shoulder arthroscopy. However, the superior trunk block (STB) is an alternative with a potentially safer profile. This meta-analysis aimed to compare the incidence and degree of hemidiaphragmatic paralysis and block efficacy of these techniques. We searched MEDLINE, EMBASE, Scopus, and Cochrane databases to identify randomized controlled trials (RCTs). The main outcome was total hemidiaphragmatic paralysis. We used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework to assess the certainty of evidence. Four RCTs and 359 patients were included. The STB group showed lower total hemidiaphragmatic paralysis (RR 0.07; 95% CI 0.04 to 0.14; p<0.0001). The incidence of subjective dyspnea (p = 0.002) and Horner's syndrome (p<0.001) was significantly lower with STB relative to ISB. There was no significant difference between groups in block duration (p = 0.67). There was a high certainty of evidence in the main outcome as per the GRADE framework. Our findings suggest that STB has a better safety profile than ISB, resulting in lower rates of hemidiaphragmatic paralysis and dyspnea while providing a similar block. Therefore, STB could be preferred to ISB, especially in patients susceptible to phrenic nerve paralysis complications.

Evolution of Perioperative Pain Management in Shoulder Arthroplasty

Historically, opioids have been used as a primary conservative treatment for pain related to glenohumeral osteoarthritis (GHOA). However, this practice is concerning as it often leads to overuse, which has contributed to the current epidemic of addiction and overdoses in the United States. Studies have shown that preoperative opioid use is associated with higher complication rates and worse outcomes following surgery, particularly for shoulder arthroplasty. To address these concerns, perioperative pain management for shoulder arthroplasty has evolved over the years to the use of multimodal analgesia.

Comparison Between Subparaneural Upper Trunk and Conventional Interscalene Blocks for Arthroscopic Shoulder Surgery: A Randomized Noninferiority Trial

BACKGROUND

Although interscalene nerve block is the standard for shoulder analgesia, the risk of hemidiaphragmatic paralysis restricts its use in patients with compromised pulmonary function. We hypothesized that a novel subparaneural upper trunk block would provide noninferior postoperative analgesia but superior diaphragmatic sparing effect compared to interscalene block.

METHODS

This randomized controlled trial comprised 96 patients who underwent arthroscopic shoulder surgery under either subparaneural upper trunk block (5 mL of 0.5% ropivacaine) or interscalene block (15 mL of 0.5% ropivacaine), followed by supraclavicular nerve block (5 mL of 0.5% ropivacaine). General anesthesia was standardized. The coprimary outcomes were (1) recovery room resting pain score at 30 minutes, measured on an 11-point numerical rating scale, with a prespecified noninferiority margin of 1 point and (2) the incidence of hemidiaphragmatic paralysis, diagnosed using ultrasound. Among secondary outcomes, resting pain scores were assessed with numerical rating scale at 4, 8, and 24 hours postoperatively.

RESULTS

Recovery room resting pain scores at 30 minutes were 0 (0-1) in the subparaneural upper trunk group versus 0 (0-0) in the interscalene group, with a median difference of 0 (95% CI, 0-0); the upper 95% CI limit was lower than the prespecified noninferiority margin (noninferiority P < .001). Hemidiaphragmatic paralysis was observed in 16.7% of patients in the subparaneural upper trunk group versus 100% of those in the interscalene group (RR, 0.17; 95% CI, 0.09-0.31; P < .001), with complete paralysis occurring in 6.3% and 93.7% of patients, respectively. In this study, any reported differences in pain scores at 4, 8, and 24 hours postoperatively were not clinically important.

CONCLUSIONS

The subparaneural upper trunk block compared to interscalene block provided noninferior analgesia at 30 minutes in the recovery room after arthroscopic shoulder surgery but resulted in less hemidiaphragmatic paralysis.

[The impact of unilateral diaphragmatic paralysis on sleep-disordered breathing: a scoping review]

BACKGROUND

Unilateral diaphragm paralysis (UDP) may potentially worsen sleep-disordered breathing (SDB). Unilateral diaphragm paralysis has been associated with proximal brachial plexus blockade, such as interscalene and supraclavicular block. The impact of UDP in patients with SDB is not known in this context. The objectives of this scoping review were to explore the associations between UDP and worsening SDB severity, oxygenation, and pulmonary function.

METHODS

A systematic search was developed, peer-reviewed, and applied to Embase, Medline, CINAHL, and Cochrane databases to include studies involving adult patients (≥ 18 yr) with SDB, where the effects of UDP on SDB severity, oxygenation, and pulmonary function were examined.

RESULTS

Six studies (n = 100 patients) with UDP and SDB were included. The sample population was derived exclusively from respirology-sleep clinics, and none were surgical patients. Compared with control (no UDP), UDP was associated with an increased respiratory disturbance index, most pronounced during rapid eye movement (REM) sleep and supine sleep. Supine and REM sleep were associated with obstructive and mixed (both obstructive and central) events, respectively. Compared with control, UDP was associated with a lower mean and minimum oxygen saturation and arterial oxygen tension during all sleep stages and in all body positions. The majority of UDP patients were found to have clinically significant reductions in mean forced expiratory volume in one second and forced vital capacity values, consistent with restrictive ventilatory pattern.

CONCLUSION

We observed an association between UDP and increasing SDB severity, particularly during REM sleep and while sleeping in the supine position. Although we identified weaknesses in study design and lack of perioperative data, anesthesiologists should be aware of this association when considering proximal brachial plexus blockade in patients with SDB.

Perioperative pain management for shoulder surgery: evolving techniques

Improving management of postoperative pain following shoulder surgery is vital for optimizing patient outcomes, length of stay, and decreasing addiction to narcotic medications. Multimodal analgesia (ie, controlling pain via multiple different analgesic methods with differing mechanisms) is an ever-evolving approach to enhancing pain control perioperatively after shoulder surgery. With a variety of options for the shoulder surgeon to turn to, this article succinctly reviews the pros and cons of each approach and proposes a potential pain management algorithm.

Ultrasound-Guided Upper Trunk Perineural Catheter for Shoulder Surgery: A Description of Catheter Technique

Interscalene brachial plexus block is frequently utilized for anesthesia and analgesia of complex and painful shoulder surgeries. But unintentional phrenic nerve blockade is a bane to the existence of this technique. Single-injection upper trunk blockade has emerged as a promising approach that appears to preserve phrenic nerve function better than the interscalene approach. The purpose of this case series is to describe the sonoanatomy, technique, and utility of a continuous upper trunk block, not previously described in the literature.

Upper trunk block for shoulder analgesia with potential phrenic nerve sparing: a preliminary anatomical report

BACKGROUND AND OBJECTIVES

Ipsilateral phrenic nerve palsy (PNP) is an undesirable side of conventional approaches to interscalene brachial plexus blocks. The purpose of this study was to demonstrate whether or not the phrenic nerve can be spared by dye when injected at the division of the upper trunk of the brachial plexus.

METHODS

Under ultrasound guidance, 5 mL of radiolabeled dye was injected between the anterior and posterior division of the upper trunk in two fresh, cryopreserved cadavers. CT scan analysis, cadaveric dissection, and cryosectioning were performed to examine the spread of the injectate.

RESULTS

We found staining of the injectate over the entire upper trunk with its anterior and posterior divisions, the suprascapular nerve under the omohyoid muscle and the lateral pectoralis nerve, and the C5 and C6 roots. The middle trunk was partially stained. There was no evidence of dye staining of the lower trunk, anterior aspect of the anterior scalene muscle, or the phrenic nerve.

CONCLUSIONS

Our study offers an anatomical basis for the possibility of providing shoulder analgesia and avoiding a PNP.