Hemofiltration Of Blood-primed Solution In Paediatric Cardiac Surgery

Objects:Current a blood prime is frequently required for pediatric cardiopulmonary bypass to maintain adequate haematocrit(HCT). Therefore we tested the hypothesis whether hemodiafiltration of the blood-primed solution is sufficient for reaching a physiologic state and investigated the effects on hemodynamics and respiratory function after cardiopulmonary bypass (CPB) in 40 patients undergoing cardiac surgery.Methods:The study population (n=40) weigh less than 8Kg undergoing heart surgery for congenital heart diseases were divided into two groups. The study group (n=20) used hemodiafiltrated stored blood in the CPB circuit for twenty minutes and the control group (n=20) used the nonultrafiltration blood. Data were obtained from the priming blood, before and after hemodiafiltrated blood prime. Blood gas test results, C-reactive protein, interleukin (IL)-8 were documented preoperatively, on cardiopulmonary bypass 30 minutes, after protamine sulfate reversal,4 hours after surgery and on the first post-operative day. The respiratory function and ICU stay time were recorded. Alveolar-arterial oxygen tension difference (AaD02) and respiratory index (RI) were calculated using PO2 and PCO2 from the arterial blood gas results after CPB in all patients. The cardiac function including left ventricular end diastolic dimension (LVED), left ventricular end systolic dimension (LVES), left ventricular end systolic pressure (Pes) and left ventricular end systolic posterior wall thickness (LVPWs) were measured by echocardiogram. Contractility was determined by percent shortening fraction (%SF), heart-rated corrected velocity of circumferential fiber shortedning (VCFc), left ventricular end systolic wall stress (WS) and stress velocity index (SVI=△VCFc-WS) Results:The measured substrates decreased significantly (P<0.01) to normal values after ultrafiltration of the blood prime (PH from 6.89±0.22 to 7.40±0.57, BE from-16.12±0.98 mmol/1 to+0.31±2.4 mmol/1, potassium from 10.33±2.13mmol/l to 4.27±0.93, glucose from 13.9±1.72 mmol/1 to 10.61±1.89mmol/l, P=0.000。Interleukin-8 (IL-8) decreased from 78.4±6.1 pg/ml to 64.3±48.1 pg/ml, P=0.036. The study group had less IL-8 (288±69pg/ml vs 377±90 pg/ml, P=0.019) and CRP (19.5±7.9 vs 36.8±17.2, P=0.002) on the first post-operative day compared with the control group. No significant differences in the white blood cell between the two groups.In both groups, there were significantly increases in AaD02 and respiratory index at 6 to 12 hours after CPB. AaD02 and RI were significantly improved in the study group compared with control group for 48 hours after CPB (P<0.05). The study group started to recover gas exchange earlier than in control group. The duration of mechanical ventilation was significantly shorter in study group than in control group (21.3±7.5 hours versus 34.0±12.6 hours, P=0.024). The clinical pulmonary function analysis results were better in the study group than the control group.There was a significant decrease in systolic and diastolic BP in both group (P=0.002,0.01). The end systolic BP decreased after CPB in both group, significantly in study group (P=0.001). But 4 hours after CPB, the systolic, diastolic and end systolic BP were significantly increased in the study group comparing the control group (P=0.02,0.003,0.001) There was a significant fall in contractility(SVI) in both group after CPB (P<0.001). Contractility improved greatly (-0.28±0.13 vs -0.01±0.21, P=0.002) in study group from the terminal of CPB to 4 hours after surgery, but did not change during the same period in the control group (-0.26±0.12 vs -0.26±0.16, P=0.33). Contractility was restored immediately in study group but not in control group. Four hours after completion of CPB contractility began to improve in control group (-0.26±0.16 vs -0.11±0.17, P=0.01). The myocardial contractility (SVI) was not significant at 24 hours of CPB.Conclusion:The usefulness of hemofiltrated stored blood for CPB priming may confer an advantage in maintaining more physiological conditions and reducing inflammatory mediators and cytokines. The therapeutic strategy may have an advantage in preventing lung and heart dysfunction in pediatric patients who need CPB priming with blood in open heart surgery.