Shailaja Kale

Dose Comparison of Tranexamic Acid in Pediatric Cardiac Surgery

To compare different doses of tranexamic acid, 150 consecutive children with congenital cyanotic heart disease were randomly assigned to one of 5 groups of 30 each. Group A served as a control. Group B received 50 mg·kg−1 of tranexamic acid at induction of anesthesia. Group C received 10 mg·kg−1 at induction followed by an infusion of 1 mg·kg−1·h−1. Group D had 10 mg·kg−1 at induction, 10 mg·kg−1 on bypass, and 10 mg·kg−1 after protamine. Group E had 20 mg·kg−1 at induction and again after protamine. The control group had the longest sternal closure time, the greatest blood loss in the first 24 hours, and the highest requirements for blood and blood products. Among the 4 groups given tranexamic acid, group D (triple dose) had the best results, followed by group E (double dose). Group B (single dose) had the worst results among the groups receiving tranexamic acid.

Management of massive air embolism during open heart surgery

Two patients in whom a massive bolus of air was introduced into the arterial circuit and ascending aorta during valve replacement and in whom the recovery was complete are presented. The technical details of the management of this serious accident are described.

Functional characterization of antibodies against heparin-platelet factor 4 complex in heparin-induced thrombocytopenia patients in Asian-Indians : relevance to inflammatory markers

Occurrence of heparin-induced thrombocytopenia (HIT) was investigated for 33 Indian patients undergoing cardiovascular surgery who received unfractionated heparin (UFH). Platelet counts were performed prior to the initiation of UFH therapy and 5–16 days post therapy. Heparin-induced platelet aggregation, 14C-serotonin release assay, and enzyme-linked immmunosorbent assay (ELISA) tests were performed in all the patients to detect the antibodies formed against the complex of heparin and platelet factor 4 (HPF4). Levels of inflammatory markers/mediators such as CD40 ligand (CD40L) and C-reactive protein (CRP) were also measured in the patient plasmas utilizing ELISA tests. Based on clinical observations and laboratory diagnoses, five patients (15%) were considered to have confirmed HIT. Despite wide variations in the titers of inflammatory markers, patients who tested ELISA-positive for HPF4 antibodies showed markedly elevated levels of both soluble CD40L and C-reactive protein. Most strikingly, the 14C-serotonin release assay-positive patients showed up to a 10-fold increase in the level of CD40L. It is concluded that approximately 15% Asian-Indian patients receiving UFH during cardiovascular surgery develop functional HPF4 antibodies, which are associated with the increased levels of inflammatory markers/mediators in this catastrophic HIT syndrome.

Blood Conservation in Open-Heart Surgery

At the All India Institute of Medical Sciences, in a 6-week period between October and November 1995, 57 patients with preoperative hemoglobin levels of more than 10 g/100mL were included in a blood conservation protocol. Autologous blood trans-fusion, total body hemodilution to a minimum hematocrit of 20%, and retransfusion of pump blood, along with meticulous intraoperative hemostasis, were performed. Forty-eight, patients (84%) did not require transfusion of homologous blood or blood products. The remaining 9 patients (including 2 who underwent reoperation, 2 who had reexploration, and 2 with preoperative renal failure) received blood or blood products when their hemoglobin fell below 8 g/100mL. No patient had postoperative hemodynamic instability or delayed recovery. All patients were discharged on oral hematinics. Blood conservation techniques are safe and easy to implement. When used in combination, they provide satisfactory results, avoid transfusion-related problems, and conserve blood supplies.