All of the following effects the height of block in spinal anesthesia except
Explanation The gender of the patient is the factor that least affects the height of the neuraxial block, among the options given. Gender can affect the block height theoretically. The density of CSF is lower in women compared with men. Although this may affect relative baricity of local anesthetics, the clinical variation in the spread is probably unimpoant. Hence this is the best answer to choose from the above options. Other Options : Age: Higher anesthetic levels are achieved in the elderly for a given dosage of spinal anesthetic. Age-related decreases in CSF volume and the higher sensitivity of the nerve roots to local anesthetic are the possible reasons. Pregnancy: Increased intraabdominal pressure or conditions that cause engorgement of the epidural veins, decrease CSF volume and thus increase block height. This includes conditions such as pregnancy, ascites, and large abdominal tumors. Height: Within the range of "normal-sized" adults, patient height does not seem to affect the spread of spinal anesthesia. But extremes of height can affect the block height.
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Central Neuraxial Blockade