Time course of changes in jugular venous oxygen saturation during hypothermic or normothermic cardiopulmonary bypass in patients with diabetes mellitus

Background: Preexisting diabetic mellitus is a risk factor determining post operative neurological disorders. The present study assesses the effects of normothermic and hypothermic cardiopulmonary bypass (CPB) on jugular venou s oxygen saturation (SjvO(2))in patients with preexisting diabetic mellitus . Methods: Sixteen diabetic patients who underwent elective coronary artery b ypass grafting surgery were randomly divided into two groups: Group DN (n=8 , diabetic patients) underwent normothermic CPB (> 35 degreesC), and group DH (n=8, diabetic patients) underwent hypothermic CPB (32 degreesC). Contro ls were 16 age-matched non-diabetic patients (normothermic group, CN: n=8; hypothermic group, CH: n=8). A 4.0 F fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor S jvO(2) values. Hemodynamic parameters and arterial and jugular venous blood gases were measured seven times. Results: Cerebral desaturation, which was defined as SjvO(2) values below 5 0%, was observed during normothermic CPB in diabetic patients (at the onset of CPB: 46 +/-3%, at 20 min after onset of CPB: 49 +/-3%, means +/- SD, re spectively). No cerebral desaturation occurred in diabetic and control pati ents during hypothermic CPB. Conclusions: Patients with preexisting diabetes mellitus experienced cerebr al desaturation during normothermic CPB.