Perineural Low-Dose Dexamethasone Prolongs Interscalene Block Analgesia With Bupivacaine Compared With Systemic Dexamethasone: A Randomized Trial

BACKGROUND AND OBJECTIVES

Perineural dexamethasone and intravenous (IV) dexamethasone have been shown to prolong peripheral nerve block duration. The effects of perineural and IV dexamethasone have only been compared at doses of 4 mg or greater. This triple-blind, randomized trial examined the effect of 1 mg IV versus perineural dexamethasone on interscalene block (ISB) analgesia duration.

METHODS

Patients undergoing ambulatory shoulder arthroscopy received an ultrasound-guided ISB with 15 mL bupivacaine 0.5% and 1 mg preservative-free dexamethasone that was administered perineurally (PeriD) or IV (IVDex). All patients received IV ketorolac and were discharged on naproxen 500 mg 2 times a day plus oxycodone/acetaminophen as needed. Peripheral nerve block duration, pain, opioid consumption, and block satisfaction were assessed via telephone follow-ups.

RESULTS

There were 63 PeriD patients and 62 IVDex patients who completed the primary outcome follow-up. The median time until analgesia from the ISB completely wore off was 3.5 hours (95% confidence interval, 1.0-6.0 hours) longer in the PeriD versus IVDex groups; P = 0.007). Time until the pain relief from the ISB began to wear off was also longer in the PeriD versus IVDex group (5.5 hours [95% confidence interval, 2.1-9.0 hours]; P = 0.002). Other secondary outcomes, including opioid consumption, satisfaction, and pain scores, were not different between groups.

CONCLUSIONS

In patients undergoing shoulder arthroscopy, low-dose perineural dexamethasone (1 mg) in combination with 15 mL of 0.5% bupivacaine prolonged the median time until pain relief from the ISB completely wore off compared with 1 mg IV dexamethasone. However, the degree of prolongation was smaller than the a priori-defined minimal clinically meaningful difference of 5 hours.

CLINICAL TRIAL REGISTRATION

This study was registered at Clinicaltrials.gov, identifier NCT02506660.

A prospective, randomized and controlled study of interscalene brachial plexus block for arthroscopic shoulder surgery: A comparison of C5 and conventional approach, a CONSORT-compliant article

BACKGROUND

The shoulder area is mainly innervated with the C5 and C6 nerve roots, and interscalene brachial plexus block (ISB) is widely used for postoperative analgesia after shoulder surgery. However, it is associated with adverse effects, such as numbness and weakness in the blocked arm due to an unwanted block of the lower brachial plexus (C7-T1). We hypothesized that the C5 approach during ISB would provide postoperative analgesia while minimizing adverse events after arthroscopic shoulder surgery.

METHODS

A total of 92 patients scheduled for arthroscopic shoulder surgery were enrolled and randomly assigned to 1 of the 3 groups: The control (no ISB, n = 31), conventional ISB (ISB with the conventional approach, n = 31), or C5 ISB (ISB with the C5 approach, n = 30) group. ISB was performed before the induction of anesthesia, and a subacromial catheter was placed in all patients at the end of the surgery. Postoperative pain scores, numbness, and weakness were recorded at 2, 8, and 24 hours after surgery. Oxygen saturation and overall patient satisfaction scores were also assessed at 1 and 48 hour after surgery, respectively.

RESULTS

The pain scores were lower in the conventional ISB group and the C5 ISB group than in the control group at postoperative 2 and 8 hours (P < 0.05). The incidence and degree of numbness and weakness of the blocked arm were significantly lower in the C5 ISB group than in the conventional ISB group (P < 0.05). Oxygen saturation were lower in the conventional ISB group and C5 ISB group than in the control group (P = 0.01). Overall patient satisfaction scores were higher in the C5 ISB group than in the control or conventional ISB group (P < 0.01).

CONCLUSION

The C5 approach for ISB provides analgesia as effectively as the conventional approach following arthroscopic shoulder surgery, with the advantages of minimal numbness and weakness.

Postoperative Analgesia in a Prolonged Continuous Interscalene Block Versus Single-Shot Block in Outpatient Arthroscopic Rotator Cuff Repair: A Prospective Randomized Study

PURPOSE

To compare the analgesic efficacy of 3-day continuous interscalene brachial plexus block versus a single-shot block for arthroscopic rotator cuff repair.

METHODS

Eighty-five patients scheduled for arthroscopic rotator cuff repair were randomly assigned to either the single-shot group (SSG) or continuous interscalene brachial block group (CG). Patients in the SSG received 2.5 mg/kg of 0.5% bupivacaine up to 25 mL; the CG received the same dose as a loading dose via catheter followed by an infusion of 0.125% bupivacaine at 5 mL/h and a patient-controlled bolus of 5 mL hourly for 72 hours. Follow-up after discharge was with telephone calls over the next 3 days. Pain was measured on a visual analog scale. Also measured were sleep disturbance, number of opioid doses taken, adverse effects, and level of patient satisfaction.

RESULTS

The median rest pain scores on the 3 days of follow-up measured on a scale of 0 to 10 (with 10 equal to greatest pain) were 0, 0, and 3 in the CG compared with 4, 4, and 3 in the SSG (P < .001) for days 1, 2, and 3, respectively. The median maximum scores were 2, 2, and 4 in the CG compared with 8, 7, and 6 in the SSG (P < .001) for the same time period.

CONCLUSIONS

A 3-day continuous interscalene brachial plexus block provides better analgesia than a single-shot block. Sleep patterns were better, and less opioid was needed after arthroscopic rotator cuff repair in patients given a continuous plexus block.

LEVEL OF EVIDENCE

Level I, prospective randomized study.

Analgesic efficacy of two interscalene blocks and one cervical epidural block in arthroscopic rotator cuff repair

PURPOSE

Despite its effectiveness in other surgeries, studies on continuous epidural block in upper-extremity surgery are rare because of technical difficulties and potential complications. This study compared postoperative analgesic efficacy and safety of ultrasound-guided continuous interscalene brachial plexus block (UCISB) and fluoroscopy-guided targeted continuous cervical epidural block (FCCEB) in arthroscopic rotator cuff repair (ARCR).

METHODS

Seventy-five patients were randomly and equally assigned to groups FCCEB (0.2%), UCISB75 (0.75%), and UCISB20 (0.2%) according to the initial ropivacaine dose (8 ml). The background infusion (0.2% ropivacaine at 5 ml/h), bolus (3 ml of 0.2% ropivacaine), and lockout time (20 min) were consistent. Respiratory effects [respiratory discomfort (modified Borg scale), ventilatory function, and hemidiaphragmatic excursion (ultrasound)], analgesic quality [pain severity at rest and motion attempt (VAS-R and -M), number of boluses, analgesic supplements, and sleep disturbance], neurologic effects, procedural discomfort, satisfaction, and adverse effects were evaluated preprocedurally and up to 72 h postoperatively.

RESULTS

FCCEB caused less respiratory depression and sensorimotor block, but had less analgesic efficacy than UCISBs (P < 0.05). FCCEB caused nausea, vomiting, and dizziness more frequently (P < 0.05) and had lower patient satisfaction than UCISBs (P < 0.05). UCISB75 can cause severe respiratory distress in patients with lung disorders. Other variables were not significantly different between the groups.

CONCLUSIONS

UCISB20 may provide superior postoperative analgesia and is the most recommendable postoperative analgesic method in ARCR.

LEVEL OF EVIDENCE

Randomized controlled trials, Therapeutic study, Level I.

The role of continuous peripheral nerve blocks

A continuous peripheral nerve block (cPNB) is provided in the hospital and ambulatory setting. The most common use of CPNBs is in the peri- and postoperative period but different indications have been described like the treatment of chronic pain such as cancer-induced pain, complex regional pain syndrome or phantom limb pain. The documented benefits strongly depend on the analgesia quality and include decreasing baseline/dynamic pain, reducing additional analgesic requirements, decrease of postoperative joint inflammation and inflammatory markers, sleep disturbances and opioid-related side effects, increase of patient satisfaction and ambulation/functioning improvement, an accelerated resumption of passive joint range-of-motion, reducing time until discharge readiness, decrease in blood loss/blood transfusions, potential reduction of the incidence of postsurgical chronic pain and reduction of costs. Evidence deriving from randomized controlled trials suggests that in some situations there are also prolonged benefits of regional anesthesia after catheter removal in addition to the immediate postoperative effects. Unfortunately, there are only few data demonstrating benefits after catheter removal and the evidence of medium- or long-term improvements in health-related quality of life measures is still lacking. This review will give an overview of the advantages and adverse effects of cPNBs.

Clinical utility of low-volume ultrasound-guided interscalene blockade: contraindications reconsidered

OBJECTIVE

The purpose of this series is to describe cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely circumventing traditional contraindications to interscalene blockade (ISB).

METHODS

Targeted low-volume ISB was performed in 3 patients in whom this procedure would typically be contraindicated because of phrenic nerve blockade or risk of local anesthetic toxicity. A patient with severe respiratory dysfunction, a patient undergoing bilateral shoulder surgery, and a patient requiring awake fiberoptic intubation underwent low-volume ultrasound-guided ISB. The ultrasound technique involved the use a low local anesthetic volume, anatomic identification of the brachial plexus trunk, needle placement opposite the phrenic nerve position, and control over local anesthetic spread.

RESULTS

In both patients in whom diaphragmatic paralysis was a concern, postoperative respiratory parameters indicated successful regional analgesia without evidence of phrenic nerve blockade. In the patient requiring an additional regional anesthetic procedure, ISB was performed with a local anesthetic volume low enough to avoid exceeding toxic safety thresholds.

CONCLUSIONS

Although further studies are warranted, we report on 3 cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely avoiding standard contraindications to ISB. Ultrasound technology may allow providers to perform low-volume brachial plexus blockade while avoiding issues related to phrenic nerve blockade and systemic local anesthetic toxicity.