Delineation of distal ulnar nerve anatomy using ultrasound in volunteers to identify an optimum approach for neural blockade:

Can We Perform Distal Nerve Block Instead of Brachial Plexus Nerve Block Under Ultrasound Guidance for Hand Surgery?

OBJECTIVE

Distal nerve blocks are used in the event of unsuccessful blocks as rescue techniques. The primary purpose of this study was to determine the sufficiency for anesthesia of distal nerve block without the need for deep sedation or general anesthesia. The secondary purpose was to compare block performance times, block onset times, and patient and surgeon satisfaction.

MATERIALS AND METHODS

Patients who underwent hand surgery associated with the innervation area of the radial and median nerves were included in the study. Thirty-four patients who were 18-65 years old and American Society of Anesthesiologists grade I-III and who were scheduled for elective hand surgery under conscious nerve block anesthesia were randomly included in an infraclavicular block group (Group I, n=17) or a radial plus median block group (Group RM, n=17). The block performance time, block onset time, satisfaction of the patient and surgeon, and number of fentanyl administrations were recorded.

RESULTS

The numbers of patients who needed fentanyl administration and conversion to general anesthesia were the same in Group I and Group RM and there was no statistically significant difference (p>0.05). The demographics, surgery times, tourniquet times, block perfomance times, and patient and surgeon satisfaction of the groups were similar and there were no statistically significant differences (p>0.05). There was a statistically significant difference in block onset times between the groups (p<0.05).

CONCLUSIONS

Conscious hand surgery can be performed under distal nerve block anesthesia safely and successfully.

Distal Peripheral Nerve Blocks in the Forearm as an Alternative to Proximal Brachial Plexus Blockade in Patients Undergoing Hand Surgery: A Prospective and Randomized Pilot Study

PURPOSE

Limited data exist regarding the role of perineural blockade of the distal median, ulnar, and radial nerves as a primary anesthetic in patients undergoing hand surgery. We conducted a prospective and randomized pilot study to compare these techniques to brachial plexus blocks as a primary anesthetic in this patient population.

METHODS

Sixty patients scheduled for hand surgery were randomized to receive either an ultrasound-guided supraclavicular, infraclavicular, or axillary nerve block (brachial plexus blocks) or ultrasound-guided median, ulnar, and radial nerve blocks performed at the level of the mid to proximal forearm (forearm blocks). The ability to undergo surgery without analgesic or local anesthetic supplementation was the primary outcome. Block procedure times, postanesthesia care unit length of stay, instances of nausea/vomiting, and need for narcotic administration were also assessed.

RESULTS

The 2 groups were similar in terms of the need for conversion to general anesthesia or analgesic or local anesthetic supplementation, with only 1 patient in the forearm block group and 2 in the brachial plexus block group requiring local anesthetic supplementation or conversion to general anesthesia. Similar durations in surgical and tourniquet times were also observed. Both groups reported similarly low numerical rating scale pain scores as well as the need for postoperative analgesic administration (2 patients in the forearm block group and 1 in the brachial plexus block group reported numerical rating scale pain scores > 0 and required opioid administration in the postanesthesia care unit). Block procedure characteristics were similar between the 2 groups.

CONCLUSIONS

Forearm blocks may be used as a primary anesthetic in patients undergoing hand surgery. Further research is warranted to determine the appropriateness of these techniques in patients undergoing surgery in the thumb or proximal to the hand.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Ultrasound guided distal peripheral nerve block of the upper limb: A technical review

Upper extremity surgery is commonly performed under regional anesthesia. The advent of ultrasonography has made performing upper extremity nerve blocks relatively easy with a high degree of reliability. The proximal approaches to brachial plexus block such as supraclavicular plexus block, infraclavicular plexus block, or the axillary block are favored for the most surgical procedures of distal upper extremity. Ultrasound guidance has however made distal nerve blocks of the upper limb a technically feasible, safe and efficacious option. In recent years, there has thus been a resurgence of distal peripheral nerve blocks to facilitate hand and wrist surgery. In this article, we review the technical aspects of performing the distal blocks of the upper extremity and highlight some of the clinical aspects of their usage.

Distal peripheral nerve blockade for patients undergoing hand surgery: a pilot study

BACKGROUND

Data are limited regarding the use of peripheral nerve blockade at the level of the forearm, and most studies regard these procedures as rescue techniques for failed or incomplete blocks. The purpose of the study was to investigate patients undergoing hand surgery with distal peripheral nerve (forearm) blocks and compare them with patients having similar procedures under more proximal brachial plexus blockade. No investigations comparing distal nerve blockade to proximal approaches are currently reported in the literature.

METHODS

Medical records were retrospectively reviewed for patients who had undergone hand surgery with a peripheral nerve block between November 2012 and October 2013. The primary outcome was the ability to provide a primary anesthetic without the need for general anesthesia or local anesthetic supplementation by the surgical team. Secondary outcome measures included narcotic administration during the block and intraoperative procedures, block performance times, and the need for rescue analgesics in the post anesthesia care unit (PACU).

RESULTS

No statistical difference in conversion rates to general anesthesia was observed between the two groups. Total opiate administration for the block and surgical procedure was lower in the forearm block group. There was no difference in block performance times or need for rescue analgesics in the PACU.

CONCLUSIONS

Forearm blocks are viable alternatives to proximal blockade and are effective as a primary anesthetic technique in patients undergoing hand surgery. Compared to the more proximal approaches, these blocks have the benefits of not causing respiratory compromise, the ability to be performed bilaterally, and may be safer in anticoagulated patients.

A triple-masked, randomized controlled trial comparing ultrasound-guided brachial plexus and distal peripheral nerve block anesthesia for outpatient hand surgery

Background. For hand surgery, brachial plexus blocks provide effective anesthesia but produce undesirable numbness. We hypothesized that distal peripheral nerve blocks will better preserve motor function while providing effective anesthesia. Methods. Adult subjects who were scheduled for elective ambulatory hand surgery under regional anesthesia and sedation were recruited and randomly assigned to receive ultrasound-guided supraclavicular brachial plexus block or distal block of the ulnar and median nerves. Each subject received 15 mL of 1.5% mepivacaine at the assigned location with 15 mL of normal saline injected in the alternate block location. The primary outcome (change in baseline grip strength measured by a hydraulic dynamometer) was tested before the block and prior to discharge. Subject satisfaction data were collected the day after surgery. Results. Fourteen subjects were enrolled. Median (interquartile range [IQR]) strength loss in the distal group was 21.4% (14.3, 47.8%), while all subjects in the supraclavicular group lost 100% of their preoperative strength, P = 0.001. Subjects in the distal group reported greater satisfaction with their block procedures on the day after surgery, P = 0.012. Conclusion. Distal nerve blocks better preserve motor function without negatively affecting quality of anesthesia, leading to increased patient satisfaction, when compared to brachial plexus block.

Does motor block related to long-acting brachial plexus block cause patient dissatisfaction after minor wrist and hand surgery? A randomized observer-blinded trial

BACKGROUND

Patient dissatisfaction has been previously associated with motor block in shoulder surgery patients receiving brachial plexus block. For elective minor wrist and hand surgery, we tested whether a regional block accelerating the early return of upper extremity motor function would improve patient satisfaction compared with a long-acting proximal brachial plexus block.

METHODS

A total of 177 patients having elective 'minor' wrist and hand surgery under awake regional block randomly received adrenalized infraclavicular lidocaine 2% 10 ml+ropivacaine 0.75% 20 ml ('long acting', n=90), or adrenalized infraclavicular lidocaine 1.5% 30 ml+long-acting distal median, radial, and ulnar nerve blocks selected according to the anticipated area of postoperative pain ('short acting', n=87). A blinded observer questioned patients on day 1 for numerically rated (0-10) subjective outcomes.

RESULTS

With 95% power, there was no evidence for a 1-point satisfaction shift in the short acting group: satisfaction was similarly high for both groups [median (inter-quartile range)=10 (8-10) vs 10 (8-10), P=0.71], and also demonstrated strong evidence for equivalence [mean difference (95% confidence interval)=-0.18 (-0.70 to 0.35)]. There was no difference between the groups for weakness- or numbness-related dissatisfaction (low for both groups), or for numerically rated or time to first pain. Surgical anaesthesia success was similar between the groups (short acting, 97% vs 93%, P=0.50), although more patients in the short acting group had surgery initiated in ≤25 min (P=0.03).

CONCLUSIONS

Patient satisfaction is not improved after elective minor wrist and hand surgery with a regional block accelerating the early return of motor function. For this surgery, motor block related to a long-acting brachial plexus block does not appear to cause patient dissatisfaction. Clinical Trial Registration number. ACTRN12610000749000, https://www.anzctr.org.au/registry/trial_review.aspx?ID=335931.