Chapter 23 - Orthopedic Anesthesia

Summary

Shoulder surgery can be accomplished arthroscopically or open, and is usually performed in either a lateral decubitus (LDP) or beach-chair (BCP) position. The LDP involves placing the patient on their side on a padded table on top of a bean bag to support the pelvis and lower torso. For the BCP, the patient is placed on a table with a headrest and the bed is positioned in Trendelenburg, with the feet elevated to 15 degrees and the knees flexed to 30 degrees. Some potential advantages of the BCP over the LDP include shorter surgical times, less difficult conversion to an open procedure, and a lower incidence of neuropathies. The BCP can present a unique challenge for the anesthesia provider in accessing the airway and has been associated with rare, but catastrophic, neurologic complications, including transient visual loss, spinal cord ischemia, and strokes. These complications have been suggested to be from the gravitational effects of the sitting position and the blunting of cerebral autoregulation under general anesthesia (GA). There is some evidence that patients in the BCP have diminished cerebral autoregulation and lower regional cerebral oxygenation, when compared to the LDP. This, however, do not relate to cognitive outcomes.