Reducing rebound pain severity after arthroscopic shoulder surgery under general anesthesia and interscalene block: a two-centre randomized controlled trial of pre-emptive opioid treatment compared with placebo.

PURPOSE: Although a single-injection interscalene block provides effective early postoperative analgesia following shoulder surgery, patients may experience "rebound pain" when the block resolves. Our objective was to determine if oral hydromorphone (2 mg) given six hours after a single-injection interscalene block for arthroscopic shoulder surgery leads to a clinically significant reduction in the severity of rebound pain. METHODS: After approval from research ethics boards, we conducted a two-centre, parallel-group, double-blind, randomized, placebo-controlled superiority trial. Patients received preoperative interscalene block, general anesthesia, and either hydromorphone or placebo six hours after the block. The primary outcome was the worst pain score in the first 24 hr postoperatively, measured on an 11-point (0-10) numerical rating scale. RESULTS: A total of 73 participants were randomly assigned to either the hydromorphone or placebo group. There was no statistically significant difference in the mean (standard deviation) worst pain score within 24 hr between the hydromorphone and placebo groups (6.5 [2.4] vs 5.9 [2.3]; mean difference, 0.6; 95% confidence interval, -0.5 to 1.8). Similarly, we did not find any significant difference in the pain trajectory, opioid use, or incidence of nausea and vomiting between the groups. The mean time to worst pain was 14.6 hr, and the mean time to first rescue analgesia was 11.3 hr after interscalene block. CONCLUSION: Hydromorphone 2 mg given six hours after interscalene block did not reduce the severity of rebound pain postoperatively compared with placebo in patients undergoing arthroscopic shoulder surgery. STUDY REGISTRATION: ClinicalTrials.gov (NCT02939209); registered 19 October 2016.

RéSUMé: OBJECTIF: Bien qu'un bloc interscalénique à injection unique fournisse une analgésie postopératoire précoce efficace après une chirurgie de l'épaule, les patient·es peuvent ressentir une « douleur de rebond ¼ lorsque le bloc se résorbe. Notre objectif était de déterminer si l'hydromorphone orale (2 mg) administrée six heures après une injection unique de bloc interscalénique pour une chirurgie arthroscopique de l'épaule entraînait une réduction cliniquement significative de la gravité de la douleur de rebond. MéTHODE: Après l'approbation des comités d'éthique de la recherche, nous avons mené une étude de supériorité dans deux centres, en groupes parallèles, à double insu, randomisée et contrôlée par placebo. Les patient·es ont reçu un bloc interscalénique préopératoire, une anesthésie générale et de l'hydromorphone ou un placebo six heures après le bloc. Le critère d'évaluation principal était le pire score de douleur au cours des premières 24 heures postopératoires, mesuré sur une échelle d'évaluation numérique de 11 points (0 à 10). RéSULTATS: Au total, 73 personnes ont participé à l'étude et ont été aléatoirement assignées au groupe hydromorphone ou au groupe placebo. Il n'y avait pas de différence statistiquement significative dans le score moyen (écart type) de la pire douleur dans les 24 heures entre les groupes hydromorphone et placebo (6,5 [2,4] vs 5,9 [2,3]; différence moyenne, 0,6; intervalle de confiance à 95 %, −0,5 à 1,8). De même, nous n'avons trouvé aucune différence significative dans la trajectoire de la douleur, la consommation d'opioïdes ou l'incidence de nausées et vomissements entre les groupes. Le temps moyen jusqu'à la pire douleur était de 14,6 heures, et le temps moyen jusqu'à la première analgésie de secours était de 11,3 heures après le bloc interscalénique. CONCLUSION: L'hydromorphone 2 mg administrée six heures après le bloc interscalénique n'a pas réduit la gravité de la douleur de rebond postopératoire par rapport au placebo chez les patient·es bénéficiant d'une chirurgie arthroscopique de l'épaule. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02939209); enregistrée le 19 octobre 2016.

Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults.

BACKGROUND: The effects of spinal anesthesia as compared with general anesthesia on the ability to walk in older adults undergoing surgery for hip fracture have not been well studied. METHODS: We conducted a pragmatic, randomized superiority trial to evaluate spinal anesthesia as compared with general anesthesia in previously ambulatory patients 50 years of age or older who were undergoing surgery for hip fracture at 46 U.S. and Canadian hospitals. Patients were randomly assigned in a 1:1 ratio to receive spinal or general anesthesia. The primary outcome was a composite of death or an inability to walk approximately 10 ft (3 m) independently or with a walker or cane at 60 days after randomization. Secondary outcomes included death within 60 days, delirium, time to discharge, and ambulation at 60 days. RESULTS: A total of 1600 patients were enrolled; 795 were assigned to receive spinal anesthesia and 805 to receive general anesthesia. The mean age was 78 years, and 67.0% of the patients were women. A total of 666 patients (83.8%) assigned to spinal anesthesia and 769 patients (95.5%) assigned to general anesthesia received their assigned anesthesia. Among patients in the modified intention-to-treat population for whom data were available, the composite primary outcome occurred in 132 of 712 patients (18.5%) in the spinal anesthesia group and 132 of 733 (18.0%) in the general anesthesia group (relative risk, 1.03; 95% confidence interval [CI], 0.84 to 1.27; P = 0.83). An inability to walk independently at 60 days was reported in 104 of 684 patients (15.2%) and 101 of 702 patients (14.4%), respectively (relative risk, 1.06; 95% CI, 0.82 to 1.36), and death within 60 days occurred in 30 of 768 (3.9%) and 32 of 784 (4.1%), respectively (relative risk, 0.97; 95% CI, 0.59 to 1.57). Delirium occurred in 130 of 633 patients (20.5%) in the spinal anesthesia group and in 124 of 629 (19.7%) in the general anesthesia group (relative risk, 1.04; 95% CI, 0.84 to 1.30). CONCLUSIONS: Spinal anesthesia for hip-fracture surgery in older adults was not superior to general anesthesia with respect to survival and recovery of ambulation at 60 days. The incidence of postoperative delirium was similar with the two types of anesthesia. (Funded by the Patient-Centered Outcomes Research Institute; REGAIN ClinicalTrials.gov number, NCT02507505.).

Critical structures in the needle path of the costoclavicular brachial plexus block: a cadaver study.

PURPOSE: The costoclavicular block is a relatively novel alternative to the infraclavicular block. We aimed to determine the anatomical structures vulnerable to needle injury during a costoclavicular block. METHODS: The needle path consistent with a costoclavicular block approach was performed bilaterally on four lightly embalmed cadavers using ultrasound guidance. Careful dissection was performed with 18-G Tuohy needles in situ and photographs were taken. RESULTS: The needle penetrated the deltoid in six of eight cases and the pectoralis minor in three of eight cases. The subclavius tendon or its fascia were punctured in two of eight cases. The lateral cord was in contact with the needle in six procedures and punctured in three. The posterior cord was contacted in two instances, and the medial cord in one. In a single dissection, the needle was in contact with the medial antebrachial cutaneous nerve. The needle was close to the medial brachial cutaneous nerve in one case and close to the pectoral nerves in two of eight cases. While the cephalic vein and thoracoacromial artery were consistently nearby, there were no cases of vascular puncture. CONCLUSION: We found that the needle path may be close to the medial antebrachial cutaneous nerve, medial brachial cutaneous nerve, and pectoral nerves but did not traverse any critical structures aside from the lateral cord. This suggests relative safety when compared with other approaches to the infraclavicular brachial plexus. Structures dans la trajectoire de l'aiguille du bloc de plexus brachial costoclaviculaire : une étude cadavérique.

RéSUMé: OBJECTIF: Le bloc costoclaviculaire est une alternative relativement nouvelle au bloc infraclaviculaire. Notre objectif était de déterminer quelles structures anatomiques étaient vulnérables aux lésions provoquées par l'aiguille pendant un bloc costoclaviculaire MéTHODE: Nous avons simulé, sous échoguidage, une trajectoire d'aiguille correspondant à l'approche pour un bloc costoclaviculaire en bilatéral sur quatre cadavres légèrement embaumés. Une dissection minutieuse a ensuite été exécutée avec des aiguilles Tuohy 18-G laissées in situ et des photographies ont été prises. RéSULTATS: L'aiguille a pénétré le deltoïde dans six des huit cas et le muscle petit pectoral dans trois des huit cas. Le tendon sous-clavier ou son fascia ont été perforés dans deux des huit cas. Le cordon latéral a été en contact avec l'aiguille dans six interventions et perforé dans trois cas. Le cordon postérieur a été touché dans deux cas, et le cordon médial dans un cas. L'aiguille a touché le nerf cutané antébrachial médial dans une seule dissection. L'aiguille était proche du nerf cutané brachial médial dans un cas et proche des nerfs pectoraux dans deux des huit cas. Alors que la veine céphalique et l'artère thoraco-acromiale étaient toujours à proximité, il n'y a eu aucun cas de ponction vasculaire. CONCLUSION: Nous avons constaté que la trajectoire de l'aiguille peut être à proximité du nerf cutané antébrachial médial, du nerf cutané brachial médial et du nerf pectoral, mais l'aiguille n'a pas traversé de structures critiques hormis le cordon latéral. Ceci suggère l'innocuité relative de ce type de bloc par rapport à d'autres approches du plexus brachial infraclaviculaire.

Continuous peripheral nerve blocks compared to thoracic epidurals or multimodal analgesia for midline laparotomy: a systematic review and meta-analysis.

BACKGROUND: Continuous peripheral nerve blocks (CPNBs) have been investigated to control pain for abdominal surgery via midline laparotomy while avoiding the adverse events of opioid or epidural analgesia. The review compiles the evidence comparing CPNBs to multimodal and epidural analgesia. METHODS: We conducted a systematic review using broad search terms in MEDLINE, EMBASE, Cochrane. Primary outcomes were pain scores and cumulative opioid consumption at 48 hours. Secondary outcomes were length of stay and postoperative nausea and vomiting (PONV). We rated the quality of the evidence using Cochrane and GRADE recommendations. The results were synthesized by meta-analysis using Revman. RESULTS: Our final selection included 26 studies (1,646 patients). There was no statistically significant difference in pain control comparing CPNBs to either multimodal or epidural analgesia (low quality evidence). Less opioids were consumed when receiving epidural analgesia than CPNBs (mean difference [MD]: -16.13, 95% CI [-32.36, 0.10]), low quality evidence) and less when receiving CPNBs than multimodal analgesia (MD: -31.52, 95% CI [-42.81, -20.22], low quality evidence). The length of hospital stay was shorter when receiving epidural analgesia than CPNBs (MD: -0.78 days, 95% CI [-1.29, -0.27], low quality evidence) and shorter when receiving CPNBs than multimodal analgesia (MD: -1.41 days, 95% CI [-2.45, -0.36], low quality evidence). There was no statistically significant difference in PONV comparing CPNBs to multimodal (high quality evidence) or epidural analgesia (moderate quality evidence). CONCLUSIONS: CPNBs should be considered a viable alternative to epidural analgesia when contraindications to epidural placement exist for patients undergoing midline laparotomies.

Practice advisory on the bleeding risks for peripheral nerve and interfascial plane blockade: evidence review and expert consensus.

The risk of bleeding complications during regional anesthesia procedures is a significant patient safety consideration. Nevertheless, existing literature provides limited guidance on the stratification of bleeding risk for peripheral nerve and newly described interfascial plane blocks. Our objective was to produce an evidence-based consensus advisory that classifies bleeding risks in patients undergoing regional peripheral nerve and interfascial plane block procedures. This advisory is intended to facilitate clinical decision-making in conjunction with national or local guidelines and to guide consideration for appropriate alterations to anticoagulation regimens before specific regional anesthesia procedures. In pursuit of this goal, the Regional Anesthesia and Acute Pain Section of the Canadian Anesthesiologists Society (CAS) assembled a panel of seven Canadian experts to classify the risk of bleeding complications associated with regional peripheral nerve and interfascial plane blocks. At the 75th annual meeting of the CAS in June 2018, the panel's expert opinion was finalized and the published literature was quantified within an organized framework. All common peripheral nerve and interfascial plane blocks were categorized into "low risk", "intermediate risk", and "high risk" based on the literature evidence, bleeding risk scores, and consensus opinion (in that order of priority). Clinical data is often limited, so readers of this consensus report should be reminded that these recommendations are mostly based on expert consensus. Hence, this advisory should not to be defined as a standard of care but rather serve as a resource for clinicians assessing the risk and benefits of regional anesthesia in management of their patients.

A Cadaver Study Investigating Structures Encountered by the Needle During a Retroclavicular Approach to Infraclavicular Brachial Plexus Block.

BACKGROUND AND OBJECTIVES: Retroclavicular block is designed to overcome the negative aspects of the commonly utilized ultrasound-guided parasagittal approach to the infraclavicular block. However, this approach necessitates the needle traversing an area posterior to the clavicle inaccessible to ultrasound wave conduction. This study sought to document the structures vulnerable to needle injury during a retroclavicular block. METHODS: A Tuohy needle was inserted using a retroclavicular approach to the infraclavicular block in 3 lightly embalmed cadavers followed by a catheter insertion 4 cm beyond the needle tip. The process was repeated on the contralateral side. With the needle and catheter in position, the cadavers were dissected and photographed. RESULTS: In 4 of the 6 dissections, the needle was directly touching the suprascapular nerve deep to the clavicle. In the remaining 2 dissections, the suprascapular nerve was within 2 cm of the needle. In 1 dissection, the suprascapular vein was indented, behind the clavicle. The trapezius was the only muscle layer traversed by the needle in all dissections. In 3 of the 6 dissections, the catheter penetrated the posterior cord. In the remaining 3, the catheter threaded along the neurovascular bundle. CONCLUSIONS: The suprascapular nerve is consistently in the path of the block needle posterior to the clavicle. This raises the possibility of risk of injury to the suprascapular nerve when using this approach to the brachial plexus. Vascular injury is also possible deep to the clavicle, and because of the noncompressible location, caution is advised in patients with disordered coagulation.

Histological confirmation of needle tip position during ultrasound-guided interscalene block: a randomized comparison between the intraplexus and the periplexus approach.

PURPOSE: Ultrasound-guided interscalene block can be performed using either periplexus or intraplexus needle placement. In this novel study, we histologically examined the needle tip position in relation to the neural tissues with the two techniques. Our objective was to investigate the variable risk of subepineurial needle tip placement resulting from the two ultrasound-guided techniques. METHODS: In an embalmed cadaveric model, periplexus or intraplexus interscalene injections were performed with the side, order, and technique assigned randomly. Under real-time ultrasound guidance, the block needle was placed next to the hyperechoic layer of the plexus (periplexus) or between the hypoechoic nerve roots (intraplexus). Once positioned, 0.1 mL of black acrylic ink was injected. The brachial plexus tissues were then removed and histology sections were prepared and then coded in order to blind two reviewers to group allocation. The area of ink staining was used to determine needle tip location, and the groups were compared for the presence of subepineurial ink. RESULTS: Twenty-six cadavers had each of the blocks performed on either brachial plexus (i.e., 52 injections). No subepineurial ink deposits were observed in the periplexus group (0%), but subepineurial ink deposition was observed in 3/26 (11.5%) intraplexus injections (odds ratio, 0; 95% confidence interval, 0 to 2.362; P = 0.235). Furthermore, in the intraplexus group, two (of the three) subepineurial ink deposits were observed under the perineurium. CONCLUSION: Although our study was somewhat underpowered due to a lower than previously reported rate of subepineurial needle tip positioning, our results suggest that there may be an increased likelihood of subepineurial needle tip position with the intraplexus approach. The periplexus technique resulted in no subepineurial spread of ink, suggesting that this approach may be less likely to result in mechanical trauma to nerves from direct needle injury.

The effects of ultrasound-guided adductor canal block versus femoral nerve block on quadriceps strength and fall risk: a blinded, randomized trial of volunteers.

BACKGROUND AND OBJECTIVES: Adductor canal block (ACB) has been suggested as an analgesic alternative to femoral nerve block (FNB) for procedures on the knee, but its effect on quadriceps motor function is unclear. We performed a randomized, blinded study to compare quadriceps strength following adductor canal versus FNB in volunteers. Our hypothesis was that quadriceps strength would be preserved following ACB, but not FNB. Secondary outcomes included relative preservation of hip adduction and degree of balance impairment. METHODS: The ACB was performed in one leg and the FNB in the contralateral leg in 16 volunteers using a randomized block sequence. For all blocks, 15 mL of 3% chloroprocaine was injected under ultrasonographic guidance. Maximal voluntary isometric contraction of knee extension and hip adduction was measured at baseline and at 30 and 60 minutes after block. After 60-minute assessments were complete, the second block was placed. A test of balance (Berg Balance Scale) was performed 30 minutes after the first block only. RESULTS: Quadriceps strength and balance scores were similar to baseline following ACB. Following FNB, there was a significant reduction in quadriceps strength (95.1% ± 17.1% vs 11.1% ± 14.0%; P < 0.0001) and balance scores (56 ± 0 vs 37 ± 17.2; P = 0.02) compared with baseline. There was no difference in hip adductor strength (97.0% ± 10.8% vs 91.8% ± 9.6%; P = 0.17). CONCLUSIONS: Compared with FNB, ACB results in significant quadriceps motor sparing and significantly preserved balance.