Abstract
The goal of positioning is to facilitate the performance of surgical procedure by surgeon while ensuring that position is physiologically safe for the anesthetized patient.In most practices the surgeon and anesthesiologist worked together to put the anesthetized patient into as ideal a position as safe as possible after induction of anesthesia. Many preventable injuries occur when an anesthesiologist does not pay scrupolous attention to details during patient positioning. The consequences of positioning need to be anticipated so that adequate preparations can be made.Patients positioning may evoke underisable physiology changes, which manifest most often as impaired venous return to the heart and interference wich ventilation to perfusion relationship in the lungs.
General anesthesia may blunt compensatory symphatetic nervous system reflex responses. That would normally minimized systemic blood pressure changes ascociated with abrupt position changes. All positions are ascociated with potential or other complication. After the induction of general anesthesia and the onset of muscle relaxation, the musculoskeletal system is susceptible to abnormal stress. Joints are normally protected from hyper extension by muscle tone, pain sensation and propioseptive reflexs. All these protection are lost in under anesthesia, joints may be placed in abnormal flexion or extension and injury may result.
These effect occurs in particular when a patient is turned, placed prone, or moved to sitting position. The cervical spine is special concern during positioning because it is highyly susceptible to injury, and such injury can have grave concequences. The head must be stabilized and held in the midline during positioning. In any patient position used, adequate venous drainage must be ensured. The patients head must be maintained in unobstructing posture, allowing internal jugular venous to drain properly. Extreem of neck flexion and rotation must be avoided especially in patient with an intra cranial mass. Protection of prominent aspect of the face and eyes must be assured especially when the prone position. The peripheral nerve are also vulnerable in anesthetized patient especially the brachially plexus and its branches are the nerves most often injuried.
In supine position, arm abduction should be limited to 90 0 degress and for the patients who are prone positioned may comfortably tolerate arm abduction greater than 90 0 degress. The ulnar nerve passes along the medial side of the humerus and becomes very superficial at the medial epicondyle. The compression of the ulnar nerve at the elbow is likely if the elbow is not protected. The radial and axillary nerve may be compressed by the screen polles or attachment to operating table. Extension of the elbow beyond a comfortable range may stretch the median nerve.The sciatic nerve can be stretch by hyper flexion of the hip and extention of the knee in patients in lithotomy position.There’s a risk of injury to proned nerve
if it's compressed between head of fibula and the bar or support structures. Pressure over medial epicondyle may result in saphenous nerve injury. There are many others of neuropathy ascociated with positioning during perioperative. Proper positioning of patients is team effort and shared responsibility between the anesthesiologist, surgeon and nurses.
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