LAR/APR Positioning of Patient, Care & Prevention of Hazards

Part 1: Introduction to LAR and APR

Part 2: Lateral Recumbent (LAR) Position

Definition

Types

• Left Lateral Recumbent (LLR): Patient lies on the left side. The standard for enemas, rectal examinations, and Sims' procedures.
• Right Lateral Recumbent (RLR): Patient lies on the right side. Used in certain cardiac and thoracic assessments.
• Lateral Decubitus: Formal clinical term, used in radiology and surgery; fully side-lying with body supported along its length.

Indications / Clinical Uses

1. Rectal examinations, enemas, and suppository insertion
2. Gynecological examinations
3. Lumbar puncture (spine flexion opens intervertebral spaces)
4. Post-anesthesia recovery (prevents aspiration)
5. Prevention of pressure injuries in bed-bound patients
6. Unconscious or seizure patients (maintains airway patency)
7. Labour and delivery (left lateral for aortocaval decompression)
8. Lateral decubitus for thoracic, renal, and hip surgery

How to Position the Patient (Step-by-Step Procedure)

1. Explain the procedure to the patient and obtain consent.
2. Raise the bed to working height and lower the side rail on the side you will position.
3. Move patient to the center of the bed to prevent falls.
4. Turn the patient onto the chosen side, supporting the head, trunk, and legs simultaneously.
5. Head alignment: Place a pillow under the head to maintain the head at the same level as the spine - the head should not sag or hyperextend.
6. Arm positioning:
   • Lower (dependent) arm: Extend slightly forward, not trapped under the body.
   • Upper arm: Supported on a pillow in front of the patient to prevent it from rolling the patient forward.
7. Leg positioning:
   • Dependent leg: Slightly flexed at the hip and knee.
   • Upper leg: Flexed more and placed on a pillow between the knees - this prevents pressure on bony prominences and reduces hip adduction stress.
8. Lumbar support: A small rolled towel or pillow placed at the waist fills the gap between the mattress and waist, maintaining spinal alignment.
9. Raise side rails and ensure the call bell is within reach.
10. Reassess position every 2 hours in bed-bound patients.

Part 3: APR (Abdominoperineal Resection) Position

Definition

• Lithotomy position (for perineal access) combined with
• Modified supine/Trendelenburg (for abdominal access)

Steps to Position the Patient for APR

1. Pre-operative assessment: Ask patient about position tolerance, preexisting neuropathies, vascular disease, BMI, and comorbidities.
2. Informed consent regarding positioning risks (nerve injury, compartment syndrome).
3. Transfer to operating table: Patient moved carefully with full team coordination.
4. Supine position established first while anesthesia is administered.
5. Lithotomy component:
   • Hips flexed to 80-100 degrees.
   • Legs abducted 30-45 degrees.
   • Knees flexed with lower legs parallel to the body trunk.
   • Both legs raised simultaneously to prevent lumbar torsion.
   • Legs placed in leg holders (candy cane stirrups or padded boot-type holders).
6. Foot section of the surgical table lowered or removed.
7. Arms placed on padded arm boards; abduction limited to <90 degrees at the shoulder.
8. Trendelenburg tilt applied as needed for abdominal exposure.
9. Padding applied to all bony prominences - heels, fibular head, sacrum, elbows.
10. Document positioning in the operative notes.

Part 4: Nursing Care During Positioning

Pre-Positioning Care

• Perform a preoperative/preprocedural risk assessment: skin integrity, nutritional status, BMI, vascular disease, neurological deficits, and pre-existing neuropathies.
• Document baseline condition of skin and neurovascular status.
• Obtain patient history of joint disorders, back pain, osteoporosis - patients with extensive kyphosis or scoliosis may require extra padding.
• Ensure adequate number of staff for safe repositioning.
• Gather all necessary positioning aids: pillows, foam wedges, padding materials, stirrups.
• Explain the position to the patient if awake and obtain cooperation.

Intra-Procedural/Intraoperative Care

• Maintain neutral spinal alignment - head, neck, and spine in one line.
• Pad all bony prominences - heels, sacrum, greater trochanter, fibular head, ear, shoulder, knee.
• Monitor dependent arm circulation continuously - check pulse oximetry in the dependent arm; low readings indicate axillary compression.
• Maintain airway patency - in LLR, monitor for airway obstruction or aspiration.
• Secure IV lines and monitoring leads away from pressure points.
• Record patient position and positioning interventions in the nursing notes per ASA guidelines.
• Check position tolerance with the patient before anesthesia induction when feasible.
• For lithotomy/APR - legs raised and lowered simultaneously and slowly to avoid hemodynamic swings.

Post-Procedure Care

• Reassess skin integrity immediately after repositioning.
• Return legs from lithotomy slowly - rapid lowering causes sudden pooling of blood into legs and acute hypotension; lower both legs simultaneously.
• Assess for neurovascular deficits: tingling, numbness, weakness in limbs.
• Reposition bed-bound patients at least every 2 hours.
• Document any postoperative complaints about numbness, vision changes, or limb pain.

Part 5: Hazards and Prevention

1. Pressure Injuries (Decubitus Ulcers)

• Pad all bony prominences before and throughout the procedure.
• Use pressure-redistributing mattresses and foam positioners.
• Reposition every 2 hours in non-surgical patients.
• Use a horseshoe head donut in lateral head positioning to reduce ocular and auricular pressure.
• Assess Braden Scale score preoperatively for high-risk patients.

2. Peripheral Nerve Injuries

• Brachial plexus: Excessive arm abduction (>90°), shoulder brace pressure, excessive head rotation away from abducted arm, or axillary compression from improper roll placement in lateral position.
• Ulnar nerve: Compression at the elbow, especially if the arm hangs unsupported.
• Common peroneal nerve: Compression at the fibular head in lithotomy or lateral position - causes foot drop.
• Femoral nerve: Excessive hip flexion and external rotation in lithotomy.
• Sciatic nerve: Excessive hip flexion combined with knee extension.

• Limit arm abduction to <90 degrees at the shoulder.
• Pad all pressure points around elbows and knees.
• Ensure the axillary roll is placed below the axilla (not in it) in lateral position - placed at the level of the thorax under the chest wall.
• Keep legs in a natural position; avoid extreme hip flexion.
• Leg holders in lithotomy should be well away from the lateral fibular head.
• Pre-operative documentation of preexisting neuropathies (double crush phenomenon).
• Intraoperative monitoring and documentation per ASA practice advisory.

3. Lower Extremity Compartment Syndrome (Lithotomy/APR)

• If surgery extends beyond 2-3 hours, periodically lower the legs.
• Avoid excessively high leg elevation.
• Monitor for signs: tense swelling of calves, pain on passive stretch, decreased distal pulses.
• Correct intraoperative hypotension promptly.
• Use padded boot-type stirrups rather than "candy cane" holders for prolonged procedures.
• Post-operative monitoring for compartment syndrome symptoms.

4. Hemodynamic Instability

• Lateral position: venous pooling, vascular compression of dependent arm causing false hypotension readings.
• Lithotomy: initial increase in venous return (cardiac overload in heart failure patients), then hypotension on leg lowering.
• Trendelenburg: autotransfusion initially, then return to baseline; increased intracranial pressure.

• Minimize interruptions to monitoring during position changes.
• Lower lithotomy legs slowly and simultaneously.
• Anticipate hemodynamic changes with preloading of IV fluids before position change.
• Monitor pulse oximetry in the dependent arm in lateral position to detect axillary compression.
• Anesthesia team should adjust settings promptly when position changes.

5. Respiratory Complications

• Lateral decubitus: ventilation-perfusion mismatch - overventilation of nondependent lung and increased perfusion to the underventilated dependent lung.
• Lithotomy and Trendelenburg: cephalad displacement of the diaphragm reduces functional residual capacity (FRC), increases atelectasis, reduces lung compliance, and raises airway pressures.
• Prone: superior ventilation-perfusion matching but risk of endotracheal tube dislodgement.

• Adjust ventilator settings after each position change.
• Use PEEP to limit atelectasis.
• Secure and confirm endotracheal tube position after every position change.
• Monitor oxygen saturation and end-tidal CO2 continuously.
• Test position tolerance before surgical draping.

6. Eye Injuries

• Direct pressure on the eye causes corneal abrasion or ischemic optic neuropathy.
• Prone or lateral position increases intraocular pressure.
• Risk of permanent visual loss in prolonged spine/prone surgeries with large blood loss, male sex, obesity, and use of a Wilson frame.

• Tape eyes shut and protect with foam padding or eye pads.
• Use horseshoe head frames to keep eyes pressure-free.
• Use lateral head pads rather than face-down positioning when possible.
• Inform patients of risk of visual loss with prolonged prone surgery.
• The entire surgical team should create a shared plan for informed consent for this complication.

7. Back Pain and Musculoskeletal Injury

• Raise and lower both legs simultaneously in lithotomy.
• Provide extra padding of the spine in patients with kyphosis or scoliosis.
• Use slight hip and knee flexion to restore lumbar lordosis in supine patients.
• Ask the patient about positions they can comfortably tolerate before induction.

8. Falls and Skin Shear

• Use positioning devices (beanbags, lateral stabilizers, table straps) to secure the patient.
• Ensure adequate staffing for transfers.
• Use slide sheets and roller boards for repositioning to minimize shear.
• Raise side rails after positioning.

Summary Table: Common Hazards and Prevention

Key Nursing Principles to Remember

1. Positioning is a team responsibility - it requires coordination of the entire surgical/nursing team.
2. Document everything - pre-positioning assessment, positioning interventions, and postoperative neurovascular checks.
3. Natural position when possible - if a patient would be uncomfortable awake, they are at risk under anesthesia.
4. Padding is necessary but not always sufficient - over-tight padding itself causes injury.
5. Duration matters - the longer the position is maintained, the greater the risk of all complications.
6. Special populations need extra assessment - obese patients, the elderly, those with peripheral vascular disease, and those with preexisting neuropathies require individualized positioning plans.
7. The 2018 ASA Practice Advisory recommends preoperative assessment of position tolerance and documentation of intraoperative positioning interventions.