Effects of ketamine on systemic vascular resistance under hypothermic cardiopulmonary bypass

Erdemli Ö., ÖZGÖK A., ÜNVER S., Ünlü S., Ebil S.

Acta Anaesthesiologica Italica / Anaesthesia and Intensive Care in Italy, cilt.49, sa.2, ss.179-184, 1998 (Scopus)

Özet

The purpose of this study was to define the effects of ketamine on systemic vascular resistance (SVR) and vascular capacitance under the constant cardiac output and stable moderate hypothermia during cardiopulmonary bypass (CPB). Thirty one patients scheduled for cardiac surgical procedures using CPB were assessed for this study. Patients were randomly assigned to one of two groups: Group I (control group, n = 12) and Group II (ketamine group, n = 19). Anesthesia was induced with fentanyl-diazepam and maintained with fentanyl injections when needed. Moderate hypothermia was applied. Variables remained constant for at least 10 minutes before initiating the test sequence. Group I received equivelent volume of saline, Group II received 2 mg/kg ketamine. Parameters were recorded at baseline and at one minute intervals for 10 minutes. Blood samples were collected from pump reservoir during the test period. In the control group, SVR remained stable for the first minute, then a significant 10.4% increase was observed compared to its baseline and 14.0% increase compared to group II, regarding to the last measurement of the test period. In the ketamine group, SVR decreased 13.7% at first minute and hardly reached to its baseline at the end. Reservoir levels and serum adrenocorticotropic hormone concentrations did not differ between the groups. We concluded that ketamine decreases SVR by arterial dilation, but has no effect on the venous vascular bed under moderate hypothermic cardiopulmonary bypass.