الفهرس 
Anatomy of the spinal cordOnly 14 pages are availabe for public view
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Abstract
Excessive bleeding in the surgical field during an intervention appears to be one of the most serious problems in spine surgery which carries the risk of significant blood loss that complicates the surgical approach.
The surgical field can be influenced by a several factors including the physical status of the patient, concomitant diseases like bleeding disorders and the pre-existing condition of the vascular network.
Controlled hypotension should be accordance with the patient’s baseline pressure which can be reduced 30% below the patient’s baseline MAP, with a minimum MAP of 60 –70 mmHg in ASA class 1 patient being clinically acceptable
For achieving controlled hypotension, there are several pharmacological and non-pharmacological techniques for appropriate control of intraoperative bleeding; the non-pharmacological (mechanical) methods for deliberate hypotension include positioning the patient and IPPV to control venous return.
The various pharmacological interventions include volatile anesthetics direct- acting vasodilator drugs (Na nitroprusside), ganglion blocking drugs, alpha- blockers, beta- blockers (atenolol, metoprolol), combined alpha and beta- blockers (labetalol), calcium channel blockers, propofol, magnesium sulfate, alpha-2 agonists(clonidine).
Those agents used either alone or in combination with each other; however, an ideal agent for inducing controlled hypotension cannot be assested. The ideal agent used for controlled hypotension