All study patients will undergo routine TTE and TEE examination protocol followed at the investigator institution. All the other routine monitoring such as end tidal carbon dioxide, urine output, ABG, ACT, BIS, electrolytes, blood sugar, hemoglobin and ventilatory parameters etc for open heart surgery will be done as per institutional practice. In the study group, the patients will receive spinal anesthesia after placement of invasive lines and prior to induction of GA.In both the study group GA will be induced with midazolam 1-2 mg, fentanyl 2μ/kg and propofol titrated to achieve loss of consciousness. Inj. Vecuronium bromide 0.1mg/kg will be used as muscle relaxant to facilitate tracheal intubation and lignocaine spray (LOX 10% spray, Neon laboratories LTD, Thane, India) will be used over vocal cords prior to intubation to blunt the sympathetic stimulation.
Subsequently anesthesia will be maintained in both the groups, with isoflurane inhalation to maintain BIS values between 40 to 60. In control group, fentanyl infusion 1μ/kg/hr will be started for analgesia, a similar looking infusion without fentanyl will be started in the spinal group.All patients will be shifted to ICU with inotropic and vasopressor support as per the hemodynamic condition.
