The effects of shoulder arthroscopy on ultrasound image quality of the interscalene brachial plexus: a pre-procedure vs post-procedure comparative study

Background Fluid extravasation from the shoulder compartment and subsequent absorption into adjacent soft tissue is a well-documented phenomenon in arthroscopic shoulder surgery. We aimed to determine if a qualitative difference in ultrasound imaging of the interscalene brachial plexus exists in relation to the timing of performing an interscalene nerve block (preoperative or postoperative). Methods This single-center, prospective observational study compared pre- and postoperative interscalene brachial plexus ultrasound images of 29 patients undergoing shoulder arthroscopy using a pretest-posttest methodology where individual patients served as their own controls. Three fellowship-trained regional anesthesiologists evaluated image quality and confidence in performing a block for each ultrasound scan using a five-point Likert scale. The association of image quality with age, gender, BMI, duration of surgery, obstructive sleep apnea, and volume of arthroscopic irrigation fluid were analyzed as secondary outcomes. Results Aggregate preoperative mean scores in quality of ultrasound visualization were higher than postoperative scores (preoperative 4.5 vs postoperative 3.8; p < .001), as was confidence in performing blockade based upon the imaging (preoperative 4.8 vs postoperative 4.2; p < .001). Larger BMI negatively affected visualization of the brachial plexus in the preoperative period (p < 0.05 for both weight categories). Patients with intermediate-high risk or confirmed obstructive sleep apnea had lower aggregate postoperative mean scores compared to the low-risk group for both ultrasound visualization (3.4 vs 4.0; p < .05) and confidence in block performance (3.8 vs 4.4; p < .05). Conclusion Due to the potential reduction of ultrasound visualization of the interscalene brachial plexus after shoulder arthroscopy, we advocate for a preoperative interscalene nerve block when feasible. Trial registration ClinicalTrials.gov (NCT03657173; September 4, 2018).

Multimodal nerve injection provides noninferior analgesic efficacy compared with interscalene nerve block after arthroscopic rotator cuff repair

Purpose: This randomized noninferiority trial aimed to evaluate whether combined suprascapular, axillary nerve, and the articular branch of lateral pectoral nerve block (3NB) is noninferior to interscalene nerve block (ISB) for pain control after arthroscopic rotator cuff repair (ASRCR). Materials and Methods: Eighty-five patients undergoing ASRCR were randomized to either 3NB (n = 43) or ISB (n = 42) group. We used 5 and 15 ml of 0.2% ropivacaine for each nerve in the 3NB and ISB groups, respectively. The primary outcome was the visual analog scale (VAS) pain score at 4 h postoperatively measured assessed on an 11-point scale (ranging from 0 = no pain to 10 = worst pain) that was analyzed using noninferiority testing. The secondary outcome was VAS pain scores in the recovery room and at 8, 12, 24, 36, 48, and 72 h postoperatively. Rebound pain, IV-PCA usage during 48 h, dyspnea, muscle weakness, and satisfaction were evaluated. Results: Regarding the primary outcome, the mean difference in VAS pain scores between the 3NB (2.5 ± 1.6) and ISB (2.2 ± 2.3) groups at 4 h postoperatively was 0.3, with a 95% confidence interval (CI) of −0.56 to 1.11. The upper limit of 95% CI is lower than the noninferiority margin of 1.3 ( p < 0.001). At all other time points, except in the recovery room, 3NB showed noninferior to ISB. Rebound pain, IV-PCA usage during the second 24 h, and muscle weakness were lower in the 3NB group (all p < 0.005). The satisfaction was similar in both groups ( p = 0.815). Conclusion: Combined 3NB is noninferior to ISB in terms of pain control after ASRCR; and is associated with low levels of rebound pain, IV-PCA usage, and muscle weakness. Level of evidence: Randomized controlled trial, Level I.

Clinical effect of normal saline injectate into interscalene nerve block catheters given within one hour of local anesthetic bolus on analgesia and hemidiaphragmatic paralysis

BackgroundPrevious case reports describe the reversal of phrenic nerve blockade from the interscalene nerve block using normal saline injectate washout. This randomized clinical trial aimed to evaluate whether using normal saline injectate to wash out local anesthetic from an interscalene nerve block catheter would restore phrenic nerve and diaphragm function, while preserving analgesia.MethodsInstitutional review board approval, clinical trial registration and consent were obtained for patients undergoing shoulder surgery with an interscalene nerve block catheter. 16 patients were randomized to receive three 10 mL aliquots of normal saline injectate (intervention group, n=8) or three sham injectates (control group, n=8) via their perineural catheters in the postanesthesia care unit (PACU). Primary outcome measures were the effects on ipsilateral hemidiaphragmatic paralysis, and secondary outcome measures included PACU opioid consumption, pain scores and change in brachial plexus sensory examination and motor function.ResultsThere was no significant difference in reversal of hemidiaphragmatic paralysis. However, there was a greater number of patients in the intervention group who ultimately displayed partial, as opposed to full, paralysis of the hemidiaphragm (p=0.03). There was no significant difference in pain scores, PACU opioid requirement, and brachial plexus motor and sensory examinations between the two groups.ConclusionsAll patients had persistent hemidiaphragmatic paralysis after the intervention, but fewer patients in the intervention group progressed to full paralysis, suggesting that a larger bolus dose of normal saline may be needed to completely reverse hemidiaphragmatic paralysis. Although normal saline injectate in 10mL increments given through the interscalene nerve block catheter had no clinically significant effect on reversing phrenic nerve blockade, it also did not lead to a reduction in analgesia and may be protective in preventing the progression to full hemidiaphragmatic paralysis.Trail registration numberNCT03677778.

Does the use of periarticular anesthetic cocktail provide adequate pain control following shoulder arthroplasty?

Background Interscalene nerve block and liposomal bupivacaine have been found to provide adequate pain control following shoulder arthroplasty. We hypothesized that local infiltration of a periarticular cocktail would provide equivalent pain control compared to interscalene nerve block and liposomal bupivacaine. Methods Eighty-seven patients undergoing primary shoulder arthroplasty were treated with local infiltration of a periarticular cocktail (200 mg of 0.5% ropivacaine, 1 mg epinephrine, and 30 mg ketorolac), local infiltration of liposomal bupivacaine, or preoperative interscalene nerve block. The outcomes of the study were postoperative visual analog scale scores, opioid consumption, length of stay, and complications. Results A total of 30 patients receiving local infiltration of a periarticular cocktail, 26 receiving liposomal bupivacaine, and 31 receiving interscalene nerve block were included in the study. Patients who received local infiltration of a periarticular cocktail had a significantly lower mean visual analog scale when compared to interscalene nerve block and liposomal bupivacaine on postoperative day 0 (2.5 versus 4.0 versus 4.8, P = 0.001 and P < 0.001). Pain scores between postoperative day 0–3 were lower in patients who received local infiltration of a periarticular cocktail, but not significantly. Patients who received local infiltration of a periarticular cocktail required significantly less opioids than the interscalene nerve block group on postoperative day 0 ( P < 0.001). Discussion A decrease in early postoperative pain and opioid consumption was found with local infiltration of a periarticular cocktail when compared with interscalene nerve block and liposomal bupivacaine after shoulder arthroplasty. Level of evidence: Level II