The interscalene approach to the brachial plexus

Clinical Report: Interscalene Block for Shoulder Operations

Administration of adequate volumes of local anaesthetic through a single injection into the interscalene space produces blockade of both the brachial and cervical plexuses. A report of 2 patients who underwent operative repair of recurrent dislocation of the shoulder under interscalene block is presented. The advantages and disadvantages of the block for surgery around the shoulder region, and the possible complications are discussed.

Regional anaesthesia in trauma

Regional anaesthesia is very effective in alleviating pain due to trauma, and is also used to provide anaesthesia for trauma surgery. It has the advantage of producing localized but complete pain relief, whilst avoiding the side effects of systemic analgesics or anaesthetics. However, regional anaesthetic drugs and techniques have potentially life-threatening complications, which the practitioner must be able to manage. This article discusses the use of regional anaesthesia, and the benefits and disadvantages of specific regional techniques in various traumatic conditions.

Effects of Interscalene Nerve Block for Postoperative Pain Management in Patients after Shoulder Surgery

Objectives. Shoulder surgery can produce severe postoperative pain and movement limitations. Evidence has shown that regional nerve block is an effective management for postoperative shoulder pain. The purpose of this study was to investigate the postoperative analgesic effect of intravenous patient-controlled analgesia (PCA) combined with interscalene nerve block in comparison to PCA alone after shoulder surgery. Methods. In this study, 103 patients receiving PCA combined with interscalene nerve block (PCAIB) and 48 patients receiving PCA alone after shoulder surgery were included. Patients' characteristics, preoperative shoulder score and range of motion, surgical and anesthetic condition in addition to visual analog scale (VAS) pain score, postoperative PCA consumption, and adverse outcomes were evaluated. Results. The results showed that PCA combined with interscalene nerve block (PCAIB) group required less volume of analgesics than PCA alone group in 24 hours (57.76 ± 23.29 mL versus 87.29 ± 33.73 mL, p < 0.001) and 48 hours (114.86 ± 40.97 mL versus 183.63 ± 44.83 mL, p < 0.001) postoperatively. The incidence of dizziness in PCAIB group was significantly lower than PCA group (resp., 1.9% and 14.6%, p = 0.005). VAS, nausea, and vomiting were less in group PCAIB, but in the absence of significant statistical correlation. Conclusion. Interscalene nerve block is effective postoperatively in reducing the demand for PCA analgesics and decreasing opioids-induced adverse events following shoulder surgery.

Hypotensive bradycardic events during shoulder arthroscopic surgery under interscalene brachial plexus blocks

Sudden, profound hypotensive and bradycardic events (HBEs) have been reported in more than 20% of patients undergoing shoulder arthroscopy in the sitting position. Although HBEs may be associated with the adverse effects of interscalene brachial plexus block (ISBPB) in the sitting position, the underlying mechanisms responsible for HBEs during the course of shoulder surgery are not well understood. The basic mechanisms of HBEs may be associated with the underlying mechanisms responsible for vasovagal syncope, carotid sinus hypersensitivity or orthostatic syncope. In this review, we discussed the possible mechanisms of HBEs during shoulder arthroscopic surgery, in the sitting position, under ISBPB. In particular, we focused on the relationship between HBEs and various types of syncopal reactions, the relationship between HBEs and the Bezold-Jarisch reflex, and the new contributing factors for the occurrence of HBEs, such as stellate ganglion block or the intraoperative administration of intravenous fentanyl.

Severe stridor and marked respiratory difficulty after right-sided supraclavicular brachial plexus block

Brachial plexus block is commonly used for upper limb surgery. Although the procedure is safe, it may be associated with some life-threatening complications. We performed right-sided supraclavicular brachial plexus block for below-elbow amputation in a 45-year-old female. At completion of the block the patient developed marked respiratory difficulty with audible inspiratory stridor. Although SpO(2) decreased to 82% initially, it was increased to 100% by continuous positive airway pressure with a face mask. On conventional direct laryngoscopy, the left vocal cord was found to be in the midline position and the right vocal cord was in the paramedian position. The trachea was intubated and surgery proceeded without any other complication. Postoperative indirect laryngoscopy revealed that the left vocal cord was fixed, whereas the right vocal cord was mobile, and diagnosis of pre-existing incomplete left vocal cord paralysis was made. This clinical report is to emphasize the importance of thorough pre-operative evaluation of the vocal cord in patients who have undergone any surgical procedure or radiation treatment of the neck before planning for brachial plexus block. If such an evaluation cannot be obtained, an alternative technique, for example axillary approach, should be preferred.

Airway difficulty after a brachial plexus subclavian perivascular block

IMPLICATIONS

We report a case of upper airway obstruction after subclavian perivascular block in a patient with a preexisting unrecognized paralyzed vocal cord on the opposite side. We discuss the incidence of vocal cord paralysis after subclavian perivascular block and the risk of airway compromise if contralateral vocal cord paralysis is known or suspected.

Perioperative interscalene blockade: an overview of its history and current clinical use

Use of single-dose and continuous interscalene brachial plexus block (ISB) are gaining widespread popularity. When compared with general anesthesia, ISB has been reported to provide superior postoperative analgesia with fewer side effects, and it is associated with greater patient satisfaction. Anatomical landmarks are readily identifiable, which contributes to the ease of performing this block. In the future, we anticipate increased use of continuous interscalene catheters or injection of biodegradable local anesthetic impregnated microspheres to provide prolonged perioperative outpatient analgesia.

Complications of peripheral blockade

The wide variety of peripheral blocks makes for a difficult endeavor in trying to grasp their many potential complications. However, the common features of these complications makes it possible to use the construct presented here, in combination with one's knowledge of anatomy, to be able anticipate many, if not most, of the complications of any particular peripheral regional anesthetic.

Brachial plexus block using a new subclavian perivascular technique: the proximal cranial needle approach

We describe the proximal cranial needle approach for brachial plexus blockade; clear surface markings and cranial direction of the needle lead to satisfactory results with a low incidence of complications.

[Interscalenic block and surgery of the shoulder. A prospective study of a continuous series of 167 patients]

OBJECTIVES

To determine the relationship between minimal stimulating current and success rate of interscalene brachial plexus block (IBPB), to assess the quality of anaesthesia and postoperative analgesia, and to evaluate the benefits and drawbacks of this technique in shoulder surgery.

STUDY DESIGN

Prospective study of a continuous series of clinical cases.

PATIENTS

Series of 167 patients undergoing shoulder surgery under IBPB, obtained with Winnie's technique, in 1995.

METHODS

The plexus was located with a nerve stimulator and an insulated needle, 25 mm long and with a short 30 degrees bevel (Stimuplex, Braun). Data were collected with questionnaires, filled in by the anaesthetists, the surgeon and patients.

RESULTS

Shoulder surgery was performed either under IBPB alone in 51.5% of cases (group A), or under IBPB associated with sedation (midazolam: 1-3 mg) in 31.7% (group B), or under IBPB associated with general anaesthesia either on the patient's request (11.4% = group C) or due to IBPB failure (5.4% = group D). The success rate was 94.6% and the efficiency of postoperative analgesia obtained in 100% of cases (no pain at admission in the recovery room). For the nerve location a minimal stimulating current of 0.08 to 1 mA (mean minimal stimulating current 0.42 +/- 0.17 mA) had been required, with a significant difference (P = 0.0001) between group A (0.38 +/- 0.14 mA) and the others (0.43 +/- 0.15 mA in group B, 0.50 +/- 0.21 mA in group C, 0.59 +/- 0.23 mA in group D).

CONCLUSIONS

The correlation between minimal stimulating current and success rate has clearly shown the benefit of the nerve stimulation. IBPB, which provides a successful and efficient anaesthesia with minimal risk and satisfactory postoperative analgesia, has become the standard technique for shoulder surgery.

False aneurysm of the axillary artery following brachial plexus block

Brachial plexus blockade is a commonly used technique for providing surgical anesthesia for the upper extremity. Although various approaches have been described, the axillary approach is the safest and most frequently used. Most complications associated with axillary nerve block are related to local or systemic anesthetic toxicity, bleeding, infection, and nerve damage. A case of false aneurysm of the axillary artery following axillary nerve block is reported. The possible occurrence of this complication should be kept in mind to avoid permanent neurologic sequelae.

Interscalene brachial plexus blocks in the management of shoulder dislocations

Interscalene brachial plexus block is a simple and effective alternative to intravenous benzodiazepines or general anaesthesia for manipulation of the dislocated shoulder. Thirty interscalene brachial plexus blocks were performed on 29 patients with dislocations of the shoulder to provide regional anaesthesia for reduction. Pain was abolished by 14 out of the 30 blocks performed, improved by 13 and unchanged by three. Muscle relaxation (MRC grade 3 or less) occurred in 21 patients. In 26 cases the block allowed reduction of the dislocation without additional analgesia or sedative. Reduction was not possible in four cases. There were no significant complications.

Reduction of shoulder dislocations under interscalene brachial blockade

Even under short sedation, reduction of shoulder dislocations is often difficult, because of the reflectory contraction of the muscles around the humeroglenoidal joint in response to pain. Administration of interscalene brachial blockade produces analgesia and complete relaxation of the muscles of the shoulder joint. We report on ten consecutive shoulder dislocations which were reduced while the patients were under interscalene brachial blockade. In all cases, reduction was easy and free from complications.

[Recurrent nerve paralysis and Claude Bernard-Horner syndrome following an interscalene block of the brachial plexus]

The association of a recurrent laryngeal block with a Horner's syndrome occurred in one patient after right interscalene brachial plexus block. Hoarseness was the main clinical symptom of recurrent paralysis and lasted 4 h. The subsequent course was totally uneventful and required no specific treatment. But the interscalene route of brachial plexus block may be potentially hazardous in the patient with a full stomach.

Interscalene brachial plexus block anesthesia for the modified Bristow procedure

Administration of local anesthetic agents into the in terscalene space usually provides adequate anesthe sia for surgical procedures on the glenohumeral joint. The anatomic basis and anesthetic technique of inter scalene brachial plexus block are described. A retro spective evaluation of 65 modified Bristow procedures is presented, in which 46 procedures performed under this form of regional anesthesia were compared with the 19 that had primary administration of general anesthesia. Those patients who had regional anesthe sia had, on the average, a shorter hospital stay, sig nificantly less blood loss, and presumably the advan tages of local anesthesia. It is suggested that inter scalene brachial plexus block be considered as a viable alternative to general anesthesia for the modi fied Bristow procedure.

Interscalene brachial plexus block: area of analgesia, complications and blood concentrations of local anesthetics

In a prospective clinical study including 100 patients, the consequences of using the interscalene approach to block the brachial plexus were investigated according to the area of analgesia, complications, and blood concentrations of local anesthetics. Sufficient analgesia of the shoulder and the upper part of the arm was obtained in 98-99% of the cases, whilst the area of analgesia in the forearm and the hand was more variable. In two groups, with 10 patients in each group, the blood concentration was measured during the first 50 min after injection in the neurovascular sheath by either the interscalene or the axillary approach. The peak values were at the same level in the two groups, but there was a much more rapid rise in concentration in the interscalene group. No toxic reactions were seen. The complications were in accordance with those reported in other publications.

Case report: inadvertent epidural anaesthesia as a complication of interscalene brachial plexus block

Bilateral phrenic nerve paralysis is described following interscalene brachial plexus block and inadvertent epidural spread is discussed as being the probable cause.

Efficacy of a nerve stimulator in regional analgesia; experience in a resident training programme

Forty interscalene brachial plexus regional blocks and twenty sciatic-femoral lower limb blocks were performed by 1st and 2nd year anaesthesia residents. Nerve trunk location was equally but randomly divided between use of a peripheral nerve stimulator and reliance on paraesthesiae. The stimulator group were sedated prior to nerve block while the non-stimulator group were similarly sedated after nerve block. There was no significant difference either in the number of needle insertions required for nerve location, or in the success rate, between stimulator and non-stimulator techniques. It is concluded that the stimulator is not a useful adjunct for nerve location, except in those patients who are unable to co-operate in eliciting paraesthesia. In such patients the stimulator permits a comparable success rate.