Comparison of the effects of red cell separation and ultrafiltration on heparin concentration during pediatric cardiac surgery

To determine the effects of red cell separation and ultrafiltration on heparin concentration. Prospective study. University-affiliated, pediatric medical center. Thirty-one children undergoing cardiac surgery. Blood sampled for heparin concentration and coagulation tests. Thirteen infants underwent modified veno-venous ultrafiltration (UF) after cardiopulmonary bypass (CPB). In addition, residual blood in the CPB circuit was hemoconcentrated by UF and reinfused (UF group). Heparin concentration increased from 2.0 ± 0.6 to 2.5 ± 0.8 U/mL, following modified UF; while activated coagulation time (ACT) decreased from 701 ± 177 to 627 ± 107 seconds. Heparin concentration of CPB circuit residual increased from 1.9 ± 0.7 to 3.1 ± 1.0 U/mL.In 18 children (older than 1 year old), the residual blood in the CPB circuit was hemoconcentrated by cell separation (CS) and reinfused (CS group). Heparin concentration of CPB circuit residual decreased from 2.6 ± 0.6 to 0.3 ± 0.2 U/mL. After reinfusion, patient heparin concentration remained unchanged at <0.05 U/mL. Thrombin time increased from 28 ± 6 to 48 ± 29 seconds and did not correlate with H. The plasma concentration of heparin increased after veno-venous modified UF of the patient. Heparin concentration also increased after UF of residual CPB circuit blood. In contrast, circuit blood hemoconcentrated by CS contained minimal heparin, and, when infused, did not increase patient's heparin concentration. ACT and thrombin time did not correlate with heparin concentration.     

Use of a dose‐dependent follow‐up protocol and mechanisms to reduce patients and staff radiation exposure in congenital and structural interventions

Background: Increasingly complex structural/congenital cardiac interventions require efforts at reducing patient/staff radiation exposure. Standard follow‐up protocols are often inadequate in detecting all patients that may have sustained radiation burns. Methods: Single‐center retrospective chart review divided into four intervals. Phase 1 (07/07–06/08, 413 procedures (proc)): follow‐up based on fluoroscopy time only; frame rate for digital acquisition (DA) 30 fps, and fluoroscopy (FL) 30 fps. Dose‐based follow‐up was used for phase 2–4. Phase 2 (07/08–08/09, 458 proc): DA: 30 fps, FL: 15 fps. Phase 3 (09/09–06/10, 350 proc): DA: 15–30 fps, FL: 15 fps, use of added radiation protection drape. Phase 4 (07/10–10/10, 89 proc): DA: 15–30 fps, FL: 15 fps, superior noise reduction filter (SNRF) with high‐quality fluoro‐record capabilities. Results: There was a significant reduction in the median cumulative air kerma between the four study periods (710 mGy vs. 566 mGy vs. 498 mGy vs. 241 mGy, P < 0.001), even though the overall fluoroscopy times remained very similar (25 min vs. 26 min vs. 26 min vs. 23 min, P = 0.957). There was a trend towards lower physician radiation exposure over the four study periods (137 mrem vs. 126 mrem vs. 108 mrem vs. 59 mrem, P = 0.15). Fifteen patients with radiation burns were identified during the study period. When changing to a dose‐based follow‐up protocol (phase 1 vs. phase 2), there was a significant increase in the incidence of detected radiation burns (0.5% vs. 2%, P = 0.04). Conclusions: Dose‐based follow‐up protocols are superior in detecting radiation burns when compared to fluoroscopy time‐based protocols. Frame rate reduction of fluoroscopy and cine acquisition and use of modified imaging equipment can achieve a significant reduction to patient/staff exposure. © 2011 Wiley‐Liss, Inc.