1.3 Patient Positioning & Safety
Key Takeaways
- Supine (dorsal recumbent) is the most common position; the safety strap is placed about 2 inches above the knees, snug but not constricting.
- Trendelenburg tilts the head down to shift abdominal contents away from the pelvis; reverse Trendelenburg tilts the head up for head, neck, and upper-abdominal access.
- Lithotomy elevates the legs in stirrups for GYN, urologic, and perineal cases; its hallmark risk is peroneal nerve injury causing foot drop, and both legs are raised and lowered together.
- Prone (face-down) carries the highest positioning risk, threatening the eyes, airway, abdomen, breasts, genitalia, and brachial plexus.
- Positioning is performed after anesthesia induction and before prep/draping; all bony prominences are padded, body alignment maintained, and a minimum of four staff are used for the prone log roll.
Goals and Timing of Positioning
Positioning has two competing aims: give the surgeon optimal exposure to the operative site, and protect the anesthetized patient, who cannot feel pain or reposition themselves. A poorly positioned patient can suffer peripheral nerve injury, pressure ulcers, circulatory compromise, musculoskeletal strain, and eye injury.
Timing is tested: the patient is positioned after anesthesia induction and before the surgical prep and draping. The anesthesia provider controls the head and airway and directs the move, while the rest of the team moves the body as a unit on the provider's count. Universal positioning principles include:
- Maintain proper body alignment — the spine, head, and limbs in neutral position.
- Pad all bony prominences (heels, sacrum, elbows, occiput, ankles) and protect nerves at the elbow (ulnar) and knee (peroneal).
- Keep the safety strap about 2 inches (5 cm) above the knees, snug but not constricting, with a hand's-breadth check.
- Secure arms on padded arm boards at less than a 90° angle, palms up (supinated), to protect the brachial plexus.
- Move slowly to avoid sudden blood-pressure shifts, and never let limbs hang off the table.
The Major Surgical Positions
| Position | Description | Common Uses | Key Risks |
|---|---|---|---|
| Supine | Face-up, flat | Abdominal, cardiac, most general cases | Ulnar/brachial plexus pressure; heel/sacral ulcers |
| Trendelenburg | Supine, head tilted down | Lower abdomen, pelvis | Sliding, shoulder pressure, raised intracranial/ocular pressure, breathing impairment |
| Reverse Trendelenburg | Supine, head tilted up | Head, neck, thyroid, upper abdomen, laparoscopic | Footboard needed; venous pooling, sliding |
| Lithotomy | Legs elevated in stirrups | GYN, urology, perineal/rectal | Peroneal nerve injury (foot drop); raise/lower legs together |
| Prone | Face-down | Spine, posterior, rectal | Eyes, airway, abdomen/breasts/genitalia, brachial plexus — highest overall risk |
| Lateral | Side-lying | Kidney (nephrectomy), hip, thoracic | Axillary roll needed; dependent eye/ear, peroneal nerve, brachial plexus |
| Fowler's / Sitting | Semi-upright to upright | Cranial, shoulder, nasal | Air embolism, hypotension, sliding |
In lithotomy, both legs must be raised and lowered simultaneously and slowly to prevent hip dislocation and a sudden cardiovascular shift. In the lateral position, an axillary roll (chest roll) is placed just below the dependent axilla — never in it — to protect the brachial plexus and circulation in the down arm.
Pressure Points, Nerve Protection, and the Prone Log Roll
Positioning injuries are largely preventable, and the CST helps guard the vulnerable structures specific to each position.
- Ulnar nerve — at risk at the medial elbow; arms are tucked or boarded with padding and palms supinated.
- Brachial plexus — injured by arm abduction beyond 90°, by an axillary roll placed too high, or by shoulder braces in steep Trendelenburg.
- Common peroneal nerve — at risk at the lateral knee in lithotomy and lateral positions; padding the stirrup contact point prevents foot drop.
- Eyes — protected in prone and sitting positions, where they must be free of all pressure to avoid blindness from retinal artery occlusion.
- Pressure ulcers — develop over the sacrum, heels, occiput, and other bony prominences; gel pads, foam, and proper alignment redistribute pressure.
Moving a patient into prone is one of the highest-risk maneuvers. It requires a coordinated log roll with a minimum of four staff plus the anesthesia provider, who protects the head and airway and calls the move. Chest rolls (bolsters) are placed from the shoulders to the iliac crests to free the abdomen for respiration and venous return; the breasts and genitalia are positioned free of pressure; the head rests in a padded face/headrest; and arms are brought down and forward ("superman") with shoulders kept under 90° of abduction.
Throughout every position, the CST and circulator confirm that lines, the Foley, and the dispersive pad are not kinked or under the patient.
Transfer, Physiologic Effects, and Teamwork
The patient first reaches the OR table by transfer. A conscious patient may move themselves with assistance, but an anesthetized or sedated patient is moved with a roller board, lateral transfer device, or draw sheet using enough staff to support the head, body, and legs. The wheels are locked on both the stretcher and the OR table, and the anesthesia provider guards the airway and lines throughout.
Positions are not just mechanical — they cause physiologic changes the CST should anticipate:
| Position | Physiologic effect to anticipate |
|---|---|
| Trendelenburg | Increased pressure on the diaphragm and lungs; raised cerebral, ocular, and venous pressure |
| Reverse Trendelenburg | Venous pooling in the legs; risk of hypotension |
| Lithotomy | Reduced lung capacity; blood-pressure drop when legs are lowered |
| Prone | Impaired ventilation if the abdomen is compressed; facial/eye pressure |
| Sitting / Fowler's | Hypotension and risk of venous air embolism |
Responsibility for positioning is shared by the whole team — surgeon, anesthesia provider, circulator, and CST — but the anesthesia provider directs the move and protects the head and airway. The CST commonly readies and pads positioning attachments (arm boards, stirrups, chest rolls, headrests), guards the sterile field during late adjustments, and watches that no body part contacts metal (a burn and pressure hazard). Final checks before draping confirm correct alignment, padded prominences, a properly placed safety strap, secured extremities, and unobstructed lines and the dispersive pad.
Documentation records the position used, devices applied, and skin condition before and after the case.
Which position tilts the patient's head downward to shift abdominal organs away from the pelvis?
What is the hallmark nerve-injury risk of the lithotomy position?
When is the patient positioned relative to anesthesia and the surgical prep?
Where is the safety strap typically placed on a supine patient?