First reported in December 2019 in Wuhan, China, novel coronavirus (SARS‐CoV‐2) has become a major challenge for health‐care systems around the world. It is estimated that about 17% of patients develop severe pneumonia, with a high incidence of acute respiratory distress syndrome (ARDS). Among the treatments for managing ARDS, prone positioning is used to improve ventilation.1 There are a few reports of neuropathies or brachial plexopathies associated with prone positioning.2-4 We present the case of a man who developed a right brachial plexopathy after prone positioning when being treated for SARS‐CoV‐2 ARDS.

A 69‐year‐old man with obesity, type 2 diabetes, hypercholesterolemia, and atrial fibrillation receiving dabigatran treatment was admitted to the emergency department due to cough, dyspnea, and fever. Bilateral pneumonia was found on chest X‐ray, and SARS‐CoV‐2 reverse transcript‐polymerase chain reaction testing by nasopharyngeal swab was positive. Due to ARDS, he was admitted to the intensive care unit (ICU) and invasive ventilation was initiated. He was in a flat prone position for the first 27 hours. General anesthesia, lopinavir/ritonavir, hydroxychloroquine, ceftriaxone, methylprednisolone, and tocilizumab were used to treat this case of coronavirus‐2019 (COVID‐19). He was discharged from the ICU after 10 days due to clinical improvement. The patient noted painless right arm weakness on regaining consciousness after general anesthesia (day 8 after ICU admission). Strength in the right arm (Medical Research Council scale) was 1/5 for humeral rotation, 1/5 for shoulder abduction, and 4/5 for elbow flexion. Sensation to light touch was decreased on the skin over the right deltoid muscle. Right biceps and brachioradialis muscle tendon reflexes were reduced. Electrodiagnostic studies were performed on a Neuropack M1 electromyography machine (Nihon Kohden, Tokyo, Japan) at 15 and 21 days after he was placed prone in the ICU. Sensory nerve conduction studies, performed on day 21, showed a reduction of more than 50% of sensory nerve action potential (SNAP) amplitudes of the right median sensory branch to the first finger and right lateral antebrachial cutaneous nerves compared with same nerves in the left arm (Table 1). Needle electromyography revealed a few fibrillation potentials and positive sharp waves on day 15, which became profuse on day 21; polyphasic enlarged motor unit potentials on day 21; and reduced recruitment in the right supraspinatus, deltoid, and biceps brachii muscles. No signs of denervation were found in the right rhomboid major, flexor carpi radialis, extensor digitorum communis, or first dorsal interosseous muscles. These findings were supportive of a postganglionic axonal lesion involving the C5 and C6 levels, suggestiing upper trunk brachial plexopathy. Cervical computerized tomography did not show an acute collection of blood or abnormalities of bone. At 1‐month follow‐up, the patient had completely recovered from COVID‐19, although previous hypoesthesia and partial right arm weakness persisted (strength 2/5 humeral rotation, 1/5 shoulder abduction, 5/5 elbow flexion).

The superficial location of the upper trunk of the brachial plexus in the supraclavicular area renders it susceptible to compression or traction injuries. Backpack palsy, burner syndrome, and classic postoperative paralysis are the most frequent causes of upper trunk brachial plexopathies.5 Surgical procedures in the prone position may cause iatrogenic neuropathies.4 A principal risk factor for brachial plexopathy in these patients is surgical mispositioning, made worse by anesthesia‐related loss of muscle tone. External rotation and abduction of the arm greater than 90°, and rotation and lateral flexion of the neck to the opposite side are the most frequently associated risk factors. In this position, nerve traction or compression between the clavicle and first rib are responsible for the plexopathy.3 Diabetes mellitus, surgical stress, and neurotoxicity of anesthesia also increase the risk in these cases. Additional inflammatory mechanisms may be associated, as epineural perivascular lymphocytic inflammation has been described in nerve biopsies.6 There are few reported cases of brachial plexopathy after prone positioning in nonsurgical ICU patients.2 Risk factors may be the same as for surgical cases. As previously reported,7 upper limbs should be placed alongside the body and padding should be placed on the patient's forehead, chest, knees, and iliac crests. The head and neck should be turned alternately to right or left every 2 hours.

Brachial plexopathies after prone positioning are not frequent, but, due to the current COVID‐19 pandemic, many patients require prone positioning due to ARDS. Careful positioning and handling of patients who are in a prone position in the ICU due to SARS‐CoV‐2 ARDS is critical for prevention of brachial plexopathies.