Post Spinal Anesthesia Shivering

This randomized controlled trial will compare the prophylactic effectiveness of low-dose intravenous ketamine and tramadol in preventing post-spinal anesthesia shivering in patients undergoing orthopedic surgery at Shaheed Mohtarma Benazir Bhutto Institute of Trauma (SMBBIT), Karachi,

The precise etiology of post-spinal anesthesia shivering (PSAS) is not fully understood. The incidence ranges between 20 to 80%. Heat loss, reduced sympathetic tone and pyrogen release are termed as the main causes of intra/postoperative shivering. The redistribution of heat from the core to the periphery of the body is facilitated by the vasodilatation associated with neuraxial anesthesia. Shivering causes tachycardia, lactic acidosis, hyperalgesia at the site of surgery, releases catecholamines, increases oxygen demand, and increases the risk of hypoxemia. \[1\]\[3\] The most common causes of shivering include fever, shivering with spinal anesthesia movement disorders, post-anesthetic shivering, fear, excitement, stress, tremors, low blood sugar, anxiety, and shivering. Shivering with spinal anesthesia is an involuntary, oscillatory muscular activity that significantly increases metabolic heat production, potentially reaching up to 600% above the basal metabolic level. Post-spinal shivering is one of the main sources of discomfort for patients recovering from surgery. Furthermore, it worsens wound pain and impedes electrocardiographic monitoring. Prophylactic intravenous administration of dexamethasone has been currently used for controlling intra-operative and post spinal anesthesia shivering. Dexamethasone's anti-inflammatory effects may thereby lessen post-anesthesia shivering by reducing the gradient between skin and core body temperatures.

This prospective, randomized, double-blind, placebo-controlled study to determine whether intrathecal dexmedetomidine, administered along with hyperbaric bupivacaine for covering Cesarean delivery decreases the incidence of shivering associated with spinal anesthesia