Pain Control Options for Shoulder Reduction

Landon Mueller, MD, CAQ-SM, Assistant Professor, Department of Emergency Medicine, Georgetown University School of Medicine, MedStar Emergency Medicine and Sports Medicine

Steven Morrin, MD, PGY1, Emergency Medicine, North Shore University Hospital and Long Island Jewish Medical Center

Case

A 21-year-old male walks into the emergency department complaining of right shoulder pain after a fall to the ground during a pickup basketball game. He is clutching his right arm in abduction and external rotation. You perform a focused physical exam, noticing a flattened contour of the shoulder. X-ray confirms your suspicion of anterior shoulder (glenohumeral) dislocation. You discuss your findings with the patient and explain the need for a closed reduction. He then grimaces and asks, “Is it going to hurt?”

"Dislocated shoulder X-ray 10” by Hellerhoff

Shoulder dislocations make up about half of all major joint dislocations encountered in the emergency department.¹ Due to pain and the risk for neurovascular compromise, it is important that the joint be reduced promptly. There are several challenges to a successful reduction: spasm of the shoulder girdle muscles due to abnormal stretching,^2,3 bony friction between the humeral head and glenoid, and patient discomfort. All reductions must use a combination of analgesia or technique to overcome these forces acting on the dislocated humerus. There have been >50 reduction techniques described in the literature, with no clear consensus of the superiority of one technique over another. Regardless of technique used, given the psychological and physical trauma associated with a closed reduction, it is essential that adequate pain control be a top priority. In this article, we will discuss the advantages and disadvantages of three different pain control approaches: procedural sedation, intra-articular injection, and interscalene nerve block.

Shoulder dislocation is one of the most common indications for procedural sedation, comprising an estimated 25-38% of all procedural sedations.^4,5 As with any type of procedural sedation, the selection of the pharmacologic agent and its dose depend on the desired effect on consciousness/muscle tone, medical comorbidities, and physician comfort. Common drugs include some combination of propofol, etomidate, ketamine, midazolam, and fentanyl.⁶ Procedural sedation is the most common approach to performing shoulder reductions due to the familiarity with emergency physicians. Sedation allows for amnesia, pain control, and muscle relaxation when achieving deep sedation. Drawbacks to procedural sedation are well described, including the risk of adverse effects (most commonly oversedation, agitation, transient hypoxia, hypotension, or emesis) and resource utilization such as the need for close patient monitoring. Additionally, the length of stay is prolonged with post-procedural monitoring, occupying valuable bed real estate.⁷

Medication Check” by Army Sgt. Andre Taylor

Intra-articular injection of lidocaine is a non-sedating option that can be performed with or without ultrasound guidance. Though the body of literature is small, there are a handful of studies demonstrating that intra-articular injections require less overall time in the ED and are associated with fewer adverse effects compared to procedural sedation.⁷ The injection is done with either landmarks or ultrasound guidance. The authors recommend ultrasound guidance to ensure delivery into the glenohumeral joint.⁸ Regardless of the approach, a successful intra-articular injection requires thorough knowledge of relevant anatomical structures. Anecdotally, some users find that intra-articular injections do not always achieve adequate pain control. This may be why some studies may have identified a lower first-time success rate when using this pain control approach.⁹ Learn how to perform an intra-articular injection.

First studied in the emergency department in 2006, interscalene nerve blocks may offer pain control comparable to procedural sedation as well as decrease ED length of stay.^10-13 As the name suggests, this nerve block anesthetizes the brachial plexus at the level between the scalene muscles. This provides analgesia to the shoulder joint capsule and blocks the muscles innervated by the C5/C6/C7 nerve roots, including the deltoid, rotator cuff, and biceps brachii. Theoretically, blockade of the shoulder girdle muscles paralyzes them, allowing relaxation and an easier reduction. While other approaches to the brachial plexus are available (supraclavicular and axillary), the interscalene approach is the only one that reliably anesthetizes the suprascapular nerve, which is important for analgesia to the shoulder joint capsule.^14-16 As with other anesthetic injections, dosing can vary. In the two emergency department trials utilizing interscalene block, doses of 20-30 mL and 15-25 mL of 1% lidocaine were used.^10,12 Of the three pain control methods discussed in this article, interscalene nerve blocks require the most technical skill. Given the site of injection, there are many possible complications: injury to the recurrent laryngeal nerve, phrenic nerve paralysis, pneumothorax, and Horner’s syndrome. Of these complications, phrenic nerve paralysis, reported as a near 100% adverse outcome by one study, is most concerning, especially in patients with significant respiratory disease (eg, chronic obstructive pulmonary disease, obesity).¹⁷ While the technique for an interscalene block is outside the scope of this article, it is strongly recommended that providers receive appropriate training prior to performing one in the department.

LEARN MORE

The selection of pain control for each patient will be informed by multiple factors: availability of equipment, patient preference, hospital protocol, and provider experience. Each method has been shown to be successful for closed shoulder reductions, though intra-articular and interscalene injections may become more prevalent as physicians receive more training and exposure.¹⁸ By learning all the various methods of pain control, you will be able to handle any reduction with skill and grace!

Case Conclusion

Since your department has multiple ultrasound machines available, you decide to take an ultrasound-guided interscalene approach. You explain risks and benefits of the procedure and obtain consent. Fifteen minutes later, you have a happy, pain-free patient with a reduced shoulder in a shoulder immobilizer. After you reassess pulses and sensation, you discharge him home with orthopedic follow-up.

References

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