Is it mandatory to maintain 30% Hematocrit in infants and pediatric cardiopulmonary bypass?-A preliminary observation

Now that techniques for the conduct of cardio-pulmonary bypass (CPB) in neonates and infants have becomestandardised, and the outcomes fairly satisfactory, the investigators have turned their attention towards improvement of existing procedures. Institutional guidelines and multidisciplinary efforts undertaken in the peri-operative period with a view to conduct bloodless CPB is an important part of this endeavour, and should be diligentlypursued by all involved caregivers. This preliminary study reflects upon the selective, most relevant requirements for successful use of asanguinous neonatal and infant cardiopulmonary circuit while maintaining acceptable level of hemodilution during the CPB, while considering the child's preoperativehematocrit value, volume of CPB circuit and the adequacy of tissue perfusion at all times.

To evaluate, measure and analyzewhether maintaining a hematocrit of 30% on pump is mandatory for pediatrics on cardiopulmonary bypass when avoiding blood in prime

Patients in the study were divided into two groups. Each group consisted of (n= 45)preschool children aged between 1–5 years. Thechildren in the study group were subjected to bloodless cardiopulmonary bypass where as the control group received blood liberally to maintain a hematocrit of 30%. A miniaturized circuit consisting of ¼ inch was used which was coated with 25% albumin for better oxygenation and platelet preservation. Affinity Pixie, Medtronic, Minneapolis, Minnesota)oxygenators were used for all the children and Sorin C5, Sorin Group, Germany, heartlung machine helped us to use the mast pump head in reducing the distance between the operating table and significantly reduce the priming volume. A hematocrit of 23% was maintained during bypass.hemofilters from Nipro, Nissho Corporation, Japan were used for conventional and modified ultrafiltration.

Preschool children aged between 1–5 years diagnosed with atrial septal defect, ventricular septal defect, tetralogy of Fallot with no known associated anomalies, coagulation disorders or neurological deficits were chosen. We also ensured that they had a preoperative hematocrit of not less than 36% and an expected pump run of not more than 90 minutes.

The study group showed Hematocrit of 25% was evidently adequate as per the data aobserved and analysed. A higher hematocrit of 30% on pump, which required blood transfusion, seemed questionable. There was no evidence ofabnormal neurological outcomes in the study group. However, long term evaluation and follow up would throw more light in the outcome though the preliminary results are satisfactory.