Influence On Bispectral Index, Cyclic Adenosine Monophosphate And The Stress Index With Ketamine

Object: To investigate the effect of ketamine through examining plasma renin activity (PRA), angiotensin- â…¡ (A- â…¡), aldosterone (ALD), cyclic adenosine monophosphate (cAMP) and observing the change of hemodynamics and bispectral index during the induction of ketamine. Methods: Twenty-four ASA I or â…¡ patient (9 males, 15 females) aged between 18-40 yr were randomly allocated to one of two groups of twelve each: controlled group (Group I ) and ketamine group (Group â…¡). Arterial blood samples in two groups were obtained at pre-administration (To). In Group I , a bolus of 0.04mg/kg midazolam was given IV 5 min ago, arterial blood samples were obtained; whereas, 3 min after a bolus of 0.04mg/kg midazolam, 2mg/kg ketamine was given in Group â…¡, and then 2 min later, arterial blood samples were obtained. Patients were maintained by intravenous-combined-inhale anesthesia. Hemodynamics was measured with HP impendence cardiography and BIS were monitored with Aspect-1000, also the concentration of PRA, A-â…¡, ALD, cAMP, blood glucouse and calcium were determined at pre (T₀) and post-administration (T₁), meanwhile, the parameter of circulation, OAA/S, BIS were recorded at the differenttime. Results: In Group I , BIS and OAA/S decreased significantly at T₁ compared with T₀. There were statistically significant on BIS and OAA/S between two groups at TI, moreover, BIS correspondingly reduced in Group II with OAA/S decreasing after midazolam were administered, but OAA/S continued to down to zero, BIS instead up to 98?after ketamine were followed. In Group II, SBP, DBP, MAP, HR, RPP greatly increased at T₁, but there were more significant changes in SBP, DBP, MAP, RPP of Group II than Group I . cAMP was significantly higher values in Group II than Group I . Conclusions: Ketamine was unable to inhibit the effect of stress; cAMP may play a role of the mechanism of ketamine; BIS was unable to represent the level of ketamine.