The Effect of Oral Clonidine Premedication on Hemodynamic Responses during Gynecologic Laparascopy under General Anesthesia

Clonidine, an alpha 2 agonist, attenuates sympathetic responses during general anesthesia and improves the intra-operative hemodynamic stability. In this randomized double blinded clinical trial study, we report the effects of 300µg oral clonidine premedication(n=22) or placebo(n=22) on hemodynamic alteration during gynecologic laparoscopic surgery, under general anesthesia. Previous works have reported the effectiveness of clonidine on blunting the sympathetic responses during open surgeries. Patients & Anesthesia consisted of isoflurane/O2 and remifentanil. Muscle relaxation was maintained by cis-atracurium. Hemodynamic data were obtained at 5 epochs: base, after induction of anesthesia, insufflation(after peumoperitoneum, supine position), trendelenburg 30 degrees, and end(after supine extubation. There was a significant increase in systolic blood pressure during peritoneal insufflation and trendelenburg position in patients in the control group(129±23, 115±29mmhg) compared with patients in the clonidine group(126±34, 116±25mmhg), P<0.05. Peritoneal insufflation and trendelenburg positioning resulted in significant increase in systolic blood pressure compared with base, in patients in both groups(control 127±15mmhg to 129±23 & 126±34mmhg clonidine 109±19mmhg to 115±29 & 116±25mmhg, P<0.05). After extubation, there was significant increase in diastolic BP in clonidine group: (98±32mmhg vs 86±8mmhg in control group). During laparoscopy, there was a significant increase in diastolic BP in the control group(89±16mmhg vs 75±18mmhg in clonidine group P<0.05). There was a significant increase in diastolic BP in the patients in clonidine group(98±32) compared with the patients in control group(86±8)P<0.05. There was significant slower HR during the procedure in both groups(71±29bpm, 63±22 vs base 85±22bpm, 85±39). It seems that clonidine can not blunt the hemodynamic responses in hyperdynamic phases after gynecologic laparoscopy in spite of its effectiveness during the procedure.