Positioning

This position is used for a variety of spine procedures, posterior fossa access, procedures of the buttocks and perirectal area as well as the lower extremities. Preoperative assessment of head, neck, shoulder, and arm mobility for positioning is very important to identify any limitations.

Use of horseshoe head rest, three-point skull fixation, or foam cushions for head stabilization.

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

Pressure points to be padded

Torso typically supported on a frame or with rolls from shoulder to iliac crest or crosswise at pelvis and shoulders.

Lower legs supported with pillows.

Upper extremities either tucked along 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 possible 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 bed, disconnect lines and circuit prior to turning
  • Decreased SV/CO/CI due to myocardial depression and vasodilation from volatile agents (blood pooling in extremities) leading to decreased preload, leading to 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 prone position due to greater lung volume posteriorly compared to anteriorly
  • Decreased TLC, decreased compliance leading to increased work of breathing
  • In case of external pressure on abdomen, the diaphragm may get pushed cephalad, decreasing functional residual capacity and compliance and result in increased peak airway pressure. Monitor for barotrauma
  • High risk for CNS damage - keep head/neck in neutral, avoid lateral rotation of head. This prevents both brachial plexus stretch injury and compromise of spinal cord blood flow
  • If head below heart level = blood/cerebrospinal fluid accumulate (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 lubrication of eyes, pad eyes with op-site, gauze and shield. Check eyes every 15 minutes during case to ensure no pressure