Superficial cervical plexus neuropathy after single-injection interscalene brachial plexus block

Intramuscular Injection and Complex Regional Pain Syndrome Development After “Harmless” Procedures

Complex regional pain syndrome (CRPS) is a puzzling pain condition, typically occurring after trauma. Incidents as innocent as IV injection and vaccine administration may serve as the impetus for an as yet poorly understood cascade of neuro-inflammation and somatosensory changes. A condition with variable degrees of psychological involvement, disability, and purely clinical diagnostic criteria, the diagnosis is often significantly delayed before effective treatment is begun, decreasing the likelihood of success. A 58-year-old female initially presented with painless peripheral edema of the left arm without erythema or loss of function, with later bilateral development of multiple domains of symptoms consistent with CRPS. Plausible initiation events in this instance were an IV insertion in the left cubital fossa and vaccination into the right deltoid. Delay in diagnosis is common but utilization of the Budapest Criteria for diagnosis and prompt treatment improves outcomes.

A fluoroscopic assessment of brachial plexus block by the supraclavicular approach: Have we been overmedicating?

Background

Ultrasonography-guided supraclavicular brachial plexus block has demonstrated safety as compared with landmark or nerve stimulation techniques. However, the minimum effective analgesic volume (MEAV) necessary for adequate blockade has not been determined. This study was undertaken to assess under fluoroscopy the postinjection spread of different drug volumes with clinical correlation. Secondary outcome measures included correlation of onset of block, block quality, and incidence of side effects.

Methods

This randomized, multiarm, cross-sectional, observational study was conducted at a single tertiary care center. A total of 549 patients were randomly allocated to 3 groups (20 ml, 30 ml, and 40 ml of drug mixture). A local anesthetic drug mixture with a radiopaque dye was administered under ultrasonographic guidance, and postinjection fluoroscopic drug spread was studied.

Results

Surgical anesthesia was achieved in 494 (89.98%) patients with 85.25%, 92.97%, and 91.71% in 20-, 30-, and 40-ml groups, respectively, being significantly low (p = 0.0317) in the 20-mL group. Cephalad and infraclavicular spread was higher in the 40-mL group than in other two groups (p = 0.103). Horner syndrome (HS) was seen in 51.18% of patients. First, ipsilateral superficial cervical plexus block was also observed in 40.22% of patients. Among patients who developed both, ∼60% of patients (99/167) belonged to the 40-mL group.

Conclusions

Optimal MEAV appears between 20 and 30 mL. Higher drug volumes are associated with more cephalad spread and side effects. Drug spread can predict block efficacy as well. It is postulated that loss of sensation in the ipsilateral neck can be used to predict development of hemidiaphragmatic paresis similar to HS.

New insights into pathways of the dorsal scapular nerve and artery for selective dorsal scapular nerve blockade

Background

The aim of this study was to clarify the topographical relationships between the dorsal scapular nerve (DSN) and the dorsal scapular artery (DSA) in the interscapular region to identify safe and convenient injection points related to DSN blockade.

Methods

Thirty shoulders of embalmed Korean cadavers and 50 live subjects were used for dissection and ultrasound (US) analysis.

Results

The running patterns of the DSA and DSN in the interscapular region were classified into 3 types. Type I was defined as nerves that were medial to the artery and parallel without changing location (80.0% of specimens). In type II (13.3%), the nerve and artery traversed one another only one time over their entire length. In type III (6.7%), the nerve and artery traversed one another, resembling a twist. Above the level of the scapular spine, the nerve was always medial to the artery. Below the scapular spine, the number of arteries was obviously decreased. Most of the arteries were lateral to the medial border of the scapula, except at the level of the superior angle of the scapula artery (SA). The positional tendency of the DSN toward the medial or lateral sides from the medial border of the scapula was similar. In US imaging of live subjects, the DSA was most observed at the level of the SA (94.0%).

Conclusions

Results of this study enhance the current knowledge regarding the pathway of the DSN and DSA and provide helpful information for selective diagnostic nerve blocks in the interscapular region.

Ultrasonography- or electrophysiology-guided suprascapular nerve block in arthroscopic acromioplasty: a prospective, double-blind, parallel-group, randomized controlled study of efficacy

PURPOSE

To evaluate the efficacy of ultrasonography-guided (UG) and electrophysiology-guided (EG) suprascapular nerve block (SNB) for arthroscopic acromioplasty with regard to pain relief.

METHODS

A prospective, double-blind, randomized controlled clinical trial was performed from June 2007 to April 2010. Patients who were scheduled for elective arthroscopic acromioplasty and who met the inclusion criteria were assigned to 1 of 2 experimental groups (UG or EG SNB) or to 1 blind group (using anatomic landmarks). Before surgery, an SNB was performed with either ultrasonographic or electrophysiologic guidance or with no assistive devices (blind). Variables were collected at 4, 24, 48, and 72 hours postoperatively.

RESULTS

Sixty-three patients were initially enrolled in the study, but 11 dropped out for various reasons. In the UG group at 4 hours, the visual analog scale score at rest (30 ± 12.0 v 39 ± 9.9 for EG group and 41 ± 11.8 for blind group) and when the patient was moving (42 ± 15.2 v 52 ± 11.5 for EG group and 53 ± 12.6 for blind group) was significantly decreased compared with the EG and blind groups (P < .05). Opioid consumption during the first 24 hours was significantly reduced in the UG and EG groups (4.3 ± 1.9 mg and 3.8 ± 2.3 mg, respectively) compared with the blind group (5.1 ± 2.2 mg) (P < .05). The visual analog scale score at rest and when the patient was moving; the pain score on the University of California, Los Angeles questionnaire; and the activities of daily living score on the American Shoulder and Elbow Surgeons questionnaire in the EG and UG groups improved more than the values in the blind group over the follow-up intervals (P < .05). Morphine consumption in the EG and UG groups by the first, second, and third days was significantly smaller than that in the blind control group (P < .05).

CONCLUSIONS

UG and EG SNB can reduce pain and painkiller consumption for up to 72 hours postoperatively. Ultrasonographic or electrophysiologic guidance is more effective than the blind method of SNB.

LEVEL OF EVIDENCE

Level I, randomized controlled trial with significant difference.

A randomized comparison between ultrasound-guided and landmark-based superficial cervical plexus block

BACKGROUND

This prospective, randomized, observer-blinded study compared ultrasound guidance and the conventional landmark-based technique for superficial cervical plexus blockade.

METHODS

Forty patients were randomly allocated to receive a block of the superficial cervical plexus using ultrasound guidance (n = 20) or the traditional landmark-based technique (n = 20). The main outcome, success, was defined as the absence of cold sensation for all 4 branches of the superficial cervical plexus at 15 mins. A blinded observer recorded success rate, onset time, block-related pain scores, and the incidence of complications. Performance time and the number of needle passes were also recorded during the performance of the block. Total anesthesia-related time was defined as the sum of performance and onset times.

RESULTS

Success rate (80%-85%) was similar between the 2 groups. Performance time was slightly longer with ultrasonography (119 versus 61 sec, P < 0.001); however, no differences in onset and total anesthesia-related times were found. There were also no differences in the number of passes and procedural discomfort.

CONCLUSIONS

Ultrasound guidance does not increase the success rate of superficial cervical plexus block compared with a landmark-based technique. Additional confirmatory trials are required.

Neurological adverse events following regional anesthesia administration

Regional anesthesia and analgesia have been associated with improved analgesia, decreased postoperative nausea and vomiting, and increased patient satisfaction for many types of surgical procedures. In obstetric anesthesia care, it has also been associated with improved maternal mortality and major morbidity. The majority of neurological adverse events following regional anesthesia administration result in temporary sensory symptoms; long-term or permanent disabling motor and sensory problems are very rare. Infection and hemorrhagic complications, particularly with neuraxial blocks, can cause neurological adverse events. More commonly, however, there are no associated secondary factors and some combination of needle trauma, intraneural injection, and/or local anesthetic toxicity may be associated, but their individual contributions to any event are difficult to define.