pethidine compared favorably with bupivacaine as the sole anesthetic agent, providing excellent conditions for lower abdominal and pelvic surgery. Some studies showed that intrathecal pethidine has short motor recovery and prolonged postoperative analgesia in comparison to intrathecal bupivacaine. The side effects of pethidine in spinal anesthesia are pruritus nausea, vomiting and respiratory depression. A dose of 1mg/kg intrathecal pethidine provides surgical anesthesia .However, its effects are not widely available in recent studies.~Dexamethasone is used as an adjuvant to local anesthetic during spinal anesthesia and other techniques of regional anesthesia, it reduces pain and prolongs the duration of post-operative analgesia. It was shown that intrathecal dexamethasone reduces the complications of spinal anesthesia such as arterial hypotension, nausea, vomiting and shivering. The investigators suppose that addition of intrathecal dexamethasone to pethidine may be a better alternative to intrathecal bupivacaine during spinal anesthesia for lower extremity orthopedic surgery with better outcome and less side effects
Bupivacaine is commonly used as a sole agent for spinal anesthesia unlike pethidine. Pethidine (meperidine) is a unique opioid. In addition to its analgesic activity, it also has significant local anesthetic activity. This property enables it to be used as the sole agent for spinal anesthesia