Most spine surgery requires patients to be positioned prone on the operating table. Patients are anesthetized and intubated supine, typically on the transport stretcher or bed, and then rolled into the prone position on the operating table. It is the shared responsibility of the anesthesiologist and surgeon to safely turn the patient prone while maintaining a secure airway and attending to intravenous lines and other monitors ensuring they remain functional. In the prone position, the patient’s arms are either fully adducted or abducted less than 90° at the shoulder and elbow joints and placed on arm boards with cushioning. The neck should also be in a neutral position neither flexed nor extended. Ulnar nerve compression and other brachial plexus injuries are recognized complications of prone positioning, and attention to proper alignment of the neck and arms is essential.

The head can rest on a pillow designed for prone positioning or be placed in Mayfield pins. Mayfield pins, commonly used for cervical spine procedures, are placed in the patient’s scalp and then secured to the operating table to optimize surgical conditions. Movement by the patient must be prevented with the use of Mayfield pins, thus, requiring vigilance with regards to the depth of anesthesia and level of paralysis. If the head is placed in a prone positioning pillow, it is imperative that the patient’s eyes, nose, ears, and chin are free from direct pressure by the pillow. There are several types of prone positioning pillows, and these are chosen by the anesthesiologist according to availability and personal preference.

There are a variety of operating tables and devices that are used to facilitate surgery in the prone position. The choice of operating table is determined by the surgeon and chosen based on surgical exposure and preservation or modification of the curvature of the spine. Both the Jackson table and the Wilson frame preserve the curvature of the spine and allow relief of pressure points at the chest and abdomen decreasing abdominal compression. With the Andrews frame, the patient is prone and kneeling which modifies the curvature of the spine allowing for better access to the lumbar spine.

The anesthetic plan should provide anesthesia while, at the same time, permitting optimal conditions for neurologic monitoring. Anesthetic agents can alter evoked potential responses. Neuromuscular-blocking agents will have a dose-dependent effect on motor evoked potentials (MEPs) due to muscle paralysis. Most anesthetic agents alter somatosensory evoked potentials (SSEPs) in relation to spinal cord ischemia, and they must be adjusted to minimize this change. Volatile agents have the most effect on SSEPs of all anesthetic agents and should be kept at less than 1 MAC to minimize the anesthetic-induced changes. Muscle relaxants are not used when monitoring MEPs. Some anesthesiologists prefer to use a propofol-opioid-based anesthetic for maintenance of anesthesia instead of using volatile agents. A central venous line may be inserted for monitoring and vascular access, and an arterial line may be inserted for blood pressure monitoring, especially when controlled hypotension may be required by the surgeon. Also, it is of prime importance that hypothermia be prevented during the surgery.