Josh Gieschen
Case:
32yo male with no PMH who presents following a fall down the stairs with no head strike or loss of consciousness. He endorses left shoulder pain and inability to range his left shoulder. He has never dislocated his shoulder before. His pain is 8/10 and limited to the L shoulder, worse with motion or palpation.
Vitals: Temp 97.6 °F | HR 87 | RR 18 | BP 119/76 | SPo2 100% on RA
Physical Exam: L arm held internally rotated, flexed, and guarded closely to torso. An obvious step-off deformity was seen directly lateral to glenoid with increased prominence of the shoulder anteriorly. Range of motion was limited severely by pain. The surrounding musculature was tense and tender to palpation. Distal sensation and pulses were intact in the bilateral upper extremities. The remainder of the physical exam was unremarkable.
The patient required hydromorphone 1mg IM during his initial evaluation for pain control. He was noted to have large muscle bulk, with anticipated difficulty with reduction. He was given 1mg lorazepam IM for anxiolysis and consented for an interscalene nerve block. The nerve block was done under ultrasound guidance.
Figure 1: Needle-in-plane posterior approach through the middle scalene to the interscalene nerve bundle.
Figure 2: Lidocaine surrounds the interscalene nerve bundle.
The patient’s shoulder was subsequently reduced using Kocher’s method.
Discussion:
In this case, the patient’s shoulder dislocation was clinically evident. POCUS was primarily employed for interscalene nerve block. Given the patient’s high muscle mass, it was anticipated that reduction without targeted analgesia and anxiolysis would be challenging and highly uncomfortable. US guidance allowed isolation of a nerve bundle that would have otherwise been difficult if not impossible to target on its own, and the resulting relaxation and pain improvement allowed reduction to proceed with ease.
Interscalene blocks are commonly used for procedures and pathology of the shoulder and upper arm. They are not recommended for indications involving the hand as the inferior trunk of the brachial plexus is often spared, leading to sparing of the ulnar nerve (1). Possible complications include phrenic nerve paralysis or Horner’s syndrome, though these are relatively rare. Because of these possible complications, interscalene blocks are relatively contraindicated in patients with respiratory insufficiency (2). Overall, interscalene blocks are a highly useful tool for analgesia and relaxation of the shoulder and upper arm and can facilitate procedures in the ED
References:
1. Operater. “Ultrasound-Guided Interscalene Brachial Plexus Nerve Block.” NYSORA, 1 Nov. 2024, www.nysora.com/techniques/upper-extremity/intescalene/ultrasound-guided-interscalene-brachial-plexus-block/.
2. Zisquit J, Nedeff N. Interscalene Block. [Updated 2022 Sep 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519491/
