Prone

This position is used for various spine procedures, including access to the posterior fossa, procedures of the buttocks and perirectal area, and lower extremity procedures.

To identify any limitations, preoperative assessment of head, neck, shoulder, and arm mobility for positioning is essential.

Use a horseshoe headrest, three-point skull fixation, or foam cushions to stabilize the head.

If conscious sedation, have the patient position themself on the operating room (OR) table, then administer sedation.

Pressure points to be padded

The torso is typically supported on a frame or with rolls from the shoulder to the iliac crest or crosswise at the pelvis and shoulders.

Lower legs supported with pillows.

Upper extremities either tucked along the body or on arm boards with arms flexed at shoulder and elbow, hands pronated (protects the Ulnar nerve). Be mindful of IV access and lines prior to tucking arms and possibly turning the OR table.

Pad pressure points at elbows, knees, ankles, and genitalia.

Ensure limited pressure on nipples and breasts placed medial to the bolsters.

Anesthetic considerations

• Intubate on the bed, disconnect lines and circuit before turning
• Decreased SV/CO/CI due to myocardial depression and vasodilation from volatile agents (blood pooling in extremities) leading to decreased preload, leading to a compensatory increase in SVR and HR, which maintains MAP
• Abdominal pressure may impede venous return due to compression of the inferior vena cava and aorta, leading to increased surgical bleeding during spine surgery due to engorgement of epidural veins
• Increased Zone 3 (a > v > A), but better ventilation in the prone position due to greater lung volume posteriorly compared to anteriorly
• Decreased TLC and decreased compliance, leading to increased work on breathing
• If external pressure is on the abdomen, the diaphragm may get pushed cephalad, decreasing functional residual capacity and compliance and increasing peak airway pressure. Monitor for barotrauma
• High risk for CNS damage - keep head/neck neutral, avoid lateral head rotation. This prevents both brachial plexus stretch injury and compromise of spinal cord blood flow
• If head below heart level = blood/cerebrospinal fluid accumulates (remember no valves, gravitational flow) = increased ICP, decreased cerebral perfusion pressure (MAP-ICP)
• At risk for facial swelling, pharyngeal, and orbital structures - may see macroglossia and airway edema
• Risk for Postoperative Visual Loss (POVL) – keep head level with or higher than the heart. Consider lubricating and padding eyes with op-site, gauze, and shield. Check eyes every 15 minutes during the case to ensure no pressure