Inflammatory response and oligo-element alterations following cardiopulmonary bypass in patients undergoing coronary artery bypass grafting.

Oligo-elements such as zinc (Zn), selenium (Se) and copper (Cu) have a significant influence on the function of the immune system. Various immunological and inflammatory changes are known to occur in patients undergoing cardiopulmonary bypass. The aim of this study was to evaluate changes in serum oligo-elements levels during and following cardiopulmonary bypass. The serum levels of Zn, Se and Cu were determined in 67 consecutive patients, with coronary artery disease admitted for coronary artery bypass grafting. Blood samples for oligo-elements, analysis were withdrawn into metal-free tubes just prior to the start of cardiopulmonary bypass; at 30, 60 and 90 min into cardiopulmonary bypass; following weaning from cardiopulmonary bypass; 30 min after termination of cardiopulmonary bypass; at 24 h; and on the 5th postoperative day. Trace elements analyses were performed using atomic absorption spectrophotometry. Interleukin 6 and 8, as well as serum albumin, creatine phosphokinase, lactate dehydrogenase and creatine phosphokinase-MB fractions were also analyzed. The mean age was 63 +/- 9 years and 91% (61) were men. The mean preoperative left ventricular function was 52 +/- 12%, Canadian Cardiovascular Society (CCS) angina class was 3.7 +/- 0.5 and 30% (20) of the operations were re-do's. All patients had normothermic cardiopulmonary bypass. Mean cardiopulmonary bypass-time was 85 +/- 31 min. One patient was lost for the recovery sampling (hospital mortality, 1.5%). Nine patients had a postoperative cardiac index < 2.0 liter/min per m2, which required pharmacological support and additional intra-aortic balloon pump in two of them. Other postoperative complications were few. There was a rapid depletion of S-selenium and S-Zn levels, which were halved at 30 min after cardiopulmonary bypass and remained low throughout the study period. The Cu/Zn ratio increased significantly at the start of cardiopulmonary bypass, which indicated an inflammatory reaction and was not normalized until the 5th postoperative day. Length of ischemia time, presence of diabetes. hypertension and hyperlipidemia did not influence the results, while a prolonged cardiopulmonary bypass-time > 120 min resulted in a higher Cu/Zn ratio than observed for shorter cardiopulmonary bypass-times. This indicates a more profound inflammatory response. Inflammatory parameters responded in the same manner as described earlier by others. These data indicate that severe loss of various oligo elements occur in patients undergoing coronary artery bypass grafting and suggests that a supplementary administration of zinc and perhaps also selenium could be appropriate during cardiopulmonary bypass.

Autologous platelet sequestration in patients undergoing coronary artery bypass grafting.

OBJECTIVES: Blood conservation remains an important issue for patients undergoing cardiac surgery with cardiopulmonary bypass. Platelet sequestration (PSQ) is an aggressive autologous blood conservation method, whose effectiveness is still debated. The main objective of the present study was to evaluate whether PSQ reduces postoperative blood transfusion requirements in patients undergoing coronary artery bypass grafting (CABG) and to determine if PSQ is a cost-effective blood conservation method. MATERIAL AND METHODS: All adult patients admitted for CABG entered the study. Exclusion criteria were: recent blood transfusion (<7 days), a platelet count of 150x10(3)/microl or less, hematocrit less than 35% and body weight 50 kg or less. The sequestration was aim 20% or more of the total platelet plasma volume. The sequestration protocol was three sequestration cycles performed just prior to surgery. The concentrated platelet portion was reinfused after weaning from the cardiopulmonary bypass. Hundred seven parameters/patients were recorded. Sixty patients entered the study; 30 in the PSQ group and 30 controls (CTR). RESULTS: Patient characteristics, operation data, preoperative hematology and coagulation parameters did not differ between the groups. In the PSQ group a mean of 433+/-34 ml concentrated platelet portion was collected. The mean platelet count in the concentrated platelet portion was 749+/-157x10(3)/microl, resulting in a platelet yield of 28+/-6% (2040%). The average total chest tube blood loss was 423 ml (PSQ) compared to 858 ml (CTR), p<0.001. A greater number of CTR patients required blood transfusion postoperatively (23) compared to PSQ (3), P<0.001, and fluid requirements were also significantly increased in the control group, P<0.001. No statistical differences in hematology and coagulation parameters between the groups were observed. The hospital mortality was low and the incidence of postoperative complications was few and without group differences. Post-extubation gas exchange was better in PSQ patients compared to CTR. CONCLUSIONS: A preoperative PSQ of a minimum 20% of the total platelet plasma volume resulted in significantly lower postoperative blood loss and fluid and blood transfusion requirements compared to controls. Post-extubation gas exchange was also better after PSQ. Only one patient did not tolerate the sequestration. No other adverse effects of the procedure were observed.