Blood conservation operations in pediatric cardiac patients: a paradigm shift of blood use.

BACKGROUND: Red blood cell transfusion is associated with high morbidity in pediatric patients undergoing cardiac operations. The aim of this study was to evaluate the clinical effects and outcomes of blood conservation for our pediatric patients undergoing cardiac operations. METHODS: We retrospectively analyzed a collected database of 168 pediatric patients who underwent biventricular (BV) and univentricular (UV) cardiac operations from 2006 to 2010. Patients were grouped into no blood conservation (n = 86 [BV = 74, UV = 12]) and blood conservation (n = 82 [BV = 68, UV = 14]) cohorts. There were no statistical differences in age, sex, weight, and preoperative or postoperative hemoglobin levels in the BV groups. RESULTS: Even though the blood conservation group had longer cardiopulmonary bypass (CPB) (p < 0.0001) and cross-clamp times (p < 0.002) with lower hemoglobin levels (p < 0.0001), there was a decreased need for intraoperative (p < 0.0001) and postoperative blood transfusions (p < 0.018), lower inotropic scores (p < 0.0001), a decrease in ventilator days (p < 0.0009), and a shorter length of hospital stay (p < 0.0008). In the UV blood conservation group, there were no statistical differences in age, sex, weight, CPB and cross-clamp times, preoperative and postoperative hemoglobin levels, and red blood cell transfusions despite lower intraoperative hemoglobin levels (p < 0.0009) and blood transfusion (p < 0.01) requirements. There were significantly lower inotropic scores (p < 0.001) and a trend toward a shorter duration of time on the ventilator (p < 0.07) in the blood conservation group. Logistic regression analysis demonstrated a significant correlation between intraoperative blood transfusion and increased inotropic score, longer duration on the ventilator, and increased length of hospitalization. CONCLUSIONS: Blood conservation in pediatric cardiac operations is associated with fewer ventilator days, lower inotropic scores, and shorter lengths of stay. These findings, in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in pediatric cardiac operations.

Gaseous microemboli in a pediatric bypass circuit with an unprimed venous line: an in vitro study.

Miniaturizing cardiopulmonary bypass (CPB) circuits to reduce hemodilution and allogenic blood product administration is common in cardiac surgery. One major concern associated with smaller CPB circuits is a possible increase in gaseous microemboli (GME) sent to the cerebral vasculature, which is exacerbated by vacuum-assisted venous drainage (VAVD). The use of VAVD has increased with smaller venous line diameter and venous cannulae. This study examines the effects of CPB initiation with an unprimed venous line and VAVD in a pediatric circuit. A CPB circuit was set up with reservoir, oxygenator, and arterial filter with a bag reservoir to simulate the patient. All trials were done in vitro, and GME were measured using the EDAC Quantifier by Luna Innovations. EDAC sensors were placed proximal and distal to the oxygenator and distal to the arterial filter. Group 1 was the control group with no VAVD and a primed venous line. Groups 2, 3, and 4 used an unprimed venous line and VAVD of -40, -20, and -10 mmHg, respectively. Total microemboli counts and total embolic load in micrometers were measured at each sensor. Groups 2 (12,379.00 +/- 3180.37) and 3 (8296.67 +/- 2818.76) had significantly more microemboli than group 1 (923.33 +/- 796.08, p < .05) at the pre-oxygenator sensor. Group 2 (57.33 +/- 25.01, p < .05) had significantly more microemboli than group 1 (5.33 +/- 3.21) at the post-oxygenator sensor. No other findings were statistically significant. The results suggest that, if an oxygenator and arterial filter with sufficient air handling capabilities are used, this method to reduce prime volume may not increase GME in the arterial line distal to the arterial filter.