Efficacy of epidural of clonidine in relieving pain after thoracotomy: study some hemodynamic, respiratory function and urodynamic changes

ABSTRACT

Thoracotomy is an operation of considerable risk, causing severe postoperative pain, and therefore creates a great need for postoperative analgesia. Our study aimed to compare between epidural morphine and clonidine as regard postoperative pain relief, hemodynamic, respiratory and urodynamic effects. In the current study, twenty adult patients scheduled to perform lobectomy through a posterolateral thoracotomy were enrolled. They were divided into two equal groups according to the analgesic drug used. Morphine Group [MG] patients received a bolus dose of morphine 0.05 mg/kg diluted in 10 cc. saline injected through thoracic epidural catheter before induction of anesthesia, followed by continuous infusion of 0.5 mg/hour diluted in 10 cc saline. Clonidine Group [CG] patients received a bolus dose of clonidine 10 micro g/kg diluted in 10 cc saline injected through thoracic epidural catheter before induction of anesthesia, followed by continuous infusion of 2 micro g/kg/hour in 10 cc saline. Our results showed that both epidural morphine and clonidine were effective for postoperative pain relief, but the quality of pain relief was better in morphine group. Both were associated with stable hemodynamic variables and improved postoperative pulmonary functions except for bradyapnea in morphine group. As regard urodynamic study, there were significant criteria for urinary retention in morphine group, whereas, there were significant criteria for increased frequency and urgency for micturation in clonidine group. Both epidural morphine and clonidine are efficient in relieving post-thoracotomy pain, but the quality of pain relief in morphine group is superior to clonidine. Also, both agents cause hemodynamic stability except clonidine was associated sometimes with bradycardia. They improved postoperative pulmonary functions due to pain relief, but morphine was sometimes associated with bradyapnea. Epidural morphine was associated with a 50% incidence of urine retention, whereas clonidine was associated with a 60% increase in frequency ad urgency of urination