Prone position

Learning objectives

Describe the physiological effects and possible complications of prone positioning
Manage patients presenting for surgery in the prone position

Prone positioning is commonly used for access to the posterior head, neck, and spine during spinal surgery, access to the retroperitoneum and upper urinary tracts, and access to posterior structures when required during plastic surgery
Prone surgery is associated with a variety of complications and requires specific considerations

Respiratory	Increased functional residual capacity
	Increased arterial oxygen pressure
	Chest wall and lung compliance remain unchanged
Cardiovascular	Reduced stroke volume
	Compensatory sympathetic tachycardia and increase in peripheral vascular resistance
	Increased pulse pressure and stroke volume variation
Cerebral blood flow	Reduced cerebral blood flow
	Increased intracranial pressure
	Vessel distension
Renal function	Slight increase in urine output

Direct pressure injuries	Skin necrosis
	Contact dermatitis
	Tracheal compression
	Salivary gland swelling
	Breast injury
	Injury to the genitalia
	Compression of the pinna
	Compression of the femoral neurovascular bundle
Indirect pressure injuries	Macroglossia and orpharyngeal swelling
	Mediastinal compression
	Visceral ischemia (liver, pancreas)
	Avascular necrosis of femoral head
	Peripheral vessel occlusion
	Limb compartment syndrome and rhabdomyolysis

Ophthalmic complications ranging from corneal abrasions to postoperative visual loss
- Direct pressure on the eye: central retinal artery occlusion
- No direct pressure on the eye: Ischemic optic neuropathy
- Risk factors: Atherosclerosis, diabetes, hypertension, male gender, blood loss, long duration of the procedure
- Prevention: Avoid direct ocular pressure
Peripheral nerve injuries
- All superficial peripheral nerves should be considered at risk
- Usually does not present in the recovery room, 90% present within 7 days
- Can be sensory or mixed motor/sensory
- Risk factors: Male gender, prolonged hospital stay, diabetes, advanced age, extremes in BMI
- Prevention: Place arms at side, <90° at elbow or shoulder if arms are abducted, avoid direct pressure in the axilla, pad the elbows