Lateral decubitus position (LDP) is inherently unstable and predisposes patients to compression and stretch injury. Damage to brachial plexus is one of the most frequent positioning injuries when patients are in lateral decubitus position.
The brachial plexus is anchored in the neck to the transverse processes of the cervical vertebrae. In upper arm, brachial plexus is fixed by axillary fascia. These fixation points make brachial plexus vulnerable to stretch injury, which is primarily mediated by ischemia of vasa nervosum. Excessive dorsal extension or lateral flexion of the neck should be avoided in LDP to prevent stretching of the brachial plexus. (1)
Another, more frequent, mechanism of brachial plexus injury seen with LDP is direct mechanical compression of the nerves. Compression of the plexus can occur when lower shoulder or arm remain directly under ribcage after position the patient in LDP. To prevent compression of the dependent brachial plexus, an “axillary roll” is placed. The term “axillary roll” is a misnomer. The roll is actually a “chest roll” and should never be placed in the axilla. The purpose of the chest roll is “… to ensure that the weight of the thorax is borne by the chest wall caudad to the axilla and avoid compression of axillary contents.” (2)
Suprascapular neuropathy is easily overlooked injury. It occurs by circumduction of the arm across the chest or lateralization of the neck toward opposite shoulder.
Position precautions should be used to prevent injuries to peripheral branches of brachial plexus as well as nerves of the lower extremities. Injury to common peroneal nerve occurs if the patient is placed on poorly padded table. To avoid lower extremity nerve injuries, dependent leg is flexed and a pillow is placed between the knees to minimize excessive pressure.
- John T. Martin, Positioning in anesthesia and surgery, 2nd edition, Saunders Company, 1987
- Ronald Miller, Manuel Pardo, Basics of Anesthesia, Elsevier Saunders, 2011
Defined by: Mikhail Galperin, MD