Positioning as a Shared Team Responsibility
Surgical positioning must balance optimal surgical exposure against the patient's safety - unlike an awake, mobile individual, an anesthetized patient cannot reposition themselves or report discomfort, placing full responsibility for injury prevention on the surgical team. The surgeon, anesthesia provider, and surgical technologist/RN each play a role: the surgeon determines the exposure needed, anesthesia monitors physiologic tolerance, and the surgical team executes safe positioning technique with appropriate padding and support devices.
General Positioning Injury Categories
- Pressure injuries - prolonged, unrelieved pressure over bony prominences reduces local blood flow, leading to tissue ischemia and, in severe cases, pressure ulcers.
- Nerve injuries - direct compression, stretch, or ischemia of a peripheral nerve during positioning can cause temporary or permanent sensory/motor deficits.
- Physiologic/circulatory effects - certain positions alter venous return, cardiac output, and ventilation, requiring anesthesia to actively manage hemodynamics.
- Compartment syndrome - prolonged limb positioning, especially in lithotomy, can reduce perfusion enough to cause compartment syndrome in rare but serious cases.
Position-Specific Nerve Injuries
| Position | Nerve at Risk | Mechanism |
|---|---|---|
| Supine | Ulnar nerve | Compression against the OR table if the arm is not properly padded or positioned in a neutral/supinated forearm position |
| Supine (arms extended) | Brachial plexus | Excessive arm abduction beyond 90 degrees stretches the plexus |
| Lithotomy | Common peroneal nerve | Compression against the lateral fibular head from poorly padded stirrups |
| Lithotomy | Femoral nerve | Excessive hip flexion compresses the nerve beneath the inguinal ligament |
| Lateral | Brachial plexus (dependent arm) | Inadequate axillary roll placement compressing the plexus against the humeral head |
| Prone | Ulnar nerve, brachial plexus | Improper arm positioning on arm boards |
| Any prolonged position | Radial nerve | Compression against the humerus, often from an improperly placed arm board or automatic blood pressure cuff |
Physiologic Effects by Position
| Position | Physiologic Effect |
|---|---|
| Trendelenburg | Increased venous return and cardiac preload; increased intracranial and intraocular pressure; abdominal contents shift cephalad, potentially restricting diaphragmatic movement and increasing peak airway pressures |
| Reverse Trendelenburg | Decreased venous return, potential hypotension; used to reduce bleeding and improve exposure in upper abdominal and some laparoscopic procedures |
| Prone | Reduced venous return if abdomen is compressed; proper chest rolls/frame use allows free abdominal excursion and reduces epidural venous pressure (important in spine surgery to reduce bleeding) |
| Lateral | Ventilation-perfusion mismatch between the dependent and non-dependent lung; the dependent lung receives more blood flow but less ventilation once one-lung ventilation techniques are used in thoracic surgery |
| Sitting/Fowler's | Risk of significant hypotension on position change and venous air embolism, particularly in procedures near major venous structures above the level of the heart |
Padding and Support Principles
- Pad every bony prominence that will bear weight in the chosen position before final securing of straps or supports.
- Use gel pads, foam positioners, or specialty devices designed for the specific position rather than improvised padding whenever available.
- Maintain neutral body alignment - avoid extreme joint flexion, extension, or rotation beyond normal physiologic range.
- Reassess position periodically during long procedures, as patient position and padding can shift, particularly during table adjustments mid-case.
- Protect the eyes in prone and lateral positions - direct pressure on the globe can cause postoperative visual loss, a rare but devastating complication.
Documentation
Position, positioning devices used, padding applied, and the names of personnel who assisted with positioning are documented on the intraoperative record. This documentation supports both patient safety review and legal accountability if a positioning-related injury is later identified.
Why the Exam Emphasizes This Topic
Positioning injuries are entirely preventable with correct technique, and the CST exam places heavy emphasis on matching each surgical position to its specific injury risks because this reflects one of the surgical technologist's direct, hands-on patient safety responsibilities. Rather than memorizing positions and injuries as disconnected facts, understand the mechanical cause behind each: compression, stretch, or ischemia at a predictable anatomical point, and you will be able to reason through any position the exam presents, even ones not explicitly covered here.