الفهرس 
Neuroaxial blocksOnly 14 pages are availabe for public view
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Abstract
Spinal anesthesia is often used in orthopedic surgery. Recently developments have led to greater patients satisfaction and accelerated functional recovery, allowing earlier discharge from hospital. Neuroaxial analgesia using only local anesthetic often provides suboptimal analgesia with higher side effects. Many drugs have been adjusted to local anesthetics to provide optimal analgesia with lower side effects such as opioids and magnesium. Commonly intrathecal local anesthetics are combined with opioids to prolong analgesia. Opioids are associated with a number of undesirable side effects including delayed respiratory depression, urine retention, pruritus, hemodynamic instability, and nausea and vomiting. Fentanyl is the most frequently intrathecal lipophilic opioid used as analgesic agent with minimal cephalic spread making it the least likely of all the intrathecal opioids to cause delayed respiratory depression. Recently, N-methyl D-aspartate receptor antagonist, magnesium sulfate, has been proposed in attempts to reduce the incidence of side effects observed when local anesthetics are used in high dose or combined with opioids Antinociceptive effect of magnesium appears to be relevant not only for chronic pain but also in postoperative pain. These effects are primarily based on regulation of calcium influx into the cell.