الفهرس 
Historical DevelopmentOnly 14 pages are availabe for public view
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Abstract
Prone positioning is a common position 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.
There are different variants of prone position with variable advantages and disadvantages for each one.
Many physiological changes occur when turning the patient into prone position including respiratory, cardiovascular and cerebrovascular changes. One of the cardiovascular changes is the decrease in cardiac output seen on turning the patient prone which is considered to be a result of reduced stroke volume. A decrease in pre-load is thought to be responsible for the reduced stroke volume that is seen. The resulting decrease in arterial pressure is, to some extent, countered by a compensatory sympathetic tachycardia and an increase in peripheral vascular resistance.
Prone positioning is associated with several important and potentially catastrophic complications which can result in permanent disability. Complications that occur from poor positioning cause morbidity, and in some cases mortality. Complications include hemodynamic changes, a range of ophthalmologic conditions, central nervous system lesions, peripheral nerve compression injuries, compartment syndrome, and pressure ulcers. Most of these complications are rare, However is very important to pay attention to them and to know how to avoid their occurrence to limit morbidity.
prone position during surgery is associated with reduced stroke volume, cardiac index, raised central venous pressure and low blood pressure. This, when combined with other factors, is associated with an increased risk for cardiovascular collapse and arrest. Risk factors include massive blood loss, hypothermia, fluid shifts, cardiac comorbidities, venous air embolism, and anatomic deformities such as thoracic lordosis or pectus excavatum, which can aggravate hypotension. So, it is important to maintain euvolemia and monitor fluid responsiveness by blood pressure variation as well as urine output especially in high risk patients.