Comparison of intrathecal and intravenous clonidine on attenuating haemodynamic response to capnoperitoneum

Background and aims: Clonidine has been used via different routes to suppress the haemodynamic stress responses associated with capnoperitoneum. This study was designed to compare the stress response attenuating effect of equal doses of intrathecal (IT) and intravenous (IV) clonidine during capnoperitoneum under general anaesthesia.

Method: Seventy-five patients satisfying inclusion criteria were randomly allocated to three groups of 25 patients each. Group C-IV patients received 1µg/kg i.v. clonidine, 15mins before induction. Group C-IT patients received the same dose intrathecally just before induction. Group N was the control group. Intraoperative haemodynamic parameters, post-operative pain and sedation were assessed. Patients requiring nitroglycerine (NTG) to maintain mean arterial pressure (MAP) below 20% of baseline were noted.

Results: There was a statistically significant difference (p=0.04) in the number of patients who required NTG between group C-IT and group C-IV [0% vs 16% (p=0.04)] and between group C-IT and group N [0% vs 36% (p=0.001)]. Rescue analgesia was required in 16 patients in group C-IV, 10 patients in group C-IT and 20 patients in group N in the first two hours after surgery.  None of the patients in either group were deeply sedated at tracheal extubation.

Conclusion: At 1µg/kg, IT clonidine is more effective than IV clonidine in suppressing haemodynamic stress response to capnoperitoneum. Both IT and IV clonidine provide early post-operative analgesia without causing much sedation.