Blood transfusion is associated with prolonged duration of mechanical ventilation in infants undergoing reparative cardiac surgery
Pediatric Critical Care Medicine. 2011;12((1):):52-6.
OBJECTIVE Perioperative transfusion has adverse effects in adults undergoing cardiac surgery. We sought to investigate whether greater use of blood and blood products might be an independent predictor of prolonged postoperative recovery, indicated by duration of mechanical ventilation (DMV), after reparative infant heart surgery. DESIGN Secondary analysis of prospectively collected data from two randomized trials of hematocrit strategy during cardiopulmonary bypass in infant heart surgery to explore the association of DMV with perioperative transfusion and other variables. SETTING Tertiary pediatric hospital. PATIENTS Two hundred seventy infants undergoing two ventricle corrective cardiac surgery without aortic arch reconstruction. MEASUREMENTS AND MAIN RESULTS In univariable analyses, longer DMV was associated with younger age and lower weight at surgery, diagnostic group, and higher intraoperative and postoperative blood product transfusion (each p < .001). In multivariable proportional hazard regression, longer total support time and greater intraoperative and early postoperative blood products per kg were the strongest predictors of longer DMV. Patients in the highest tertile of intraoperative blood products per kg had an instantaneous risk of being extubated approximately half that of patients in the lowest tertile (hazard ratio, 0.51; 95% confidence interval, 0.35, 0.73). Patients who received any blood products on postoperative day 1, compared with those who did not, had a hazard ratio for extubation of 0.65 (95% confidence interval, 0.50, 0.85). CONCLUSIONS In this exploratory secondary analysis of infants undergoing two ventricular repair of congenital heart disease without aortic arch obstruction, greater intraoperative and early postoperative blood transfusion emerged as potential important risk factors for longer DMV. Future prospective clinical trials are needed to determine whether reduction in blood product administration hastens postoperative recovery after infant heart surgery.
The influence of hemodilution on outcome after hypothermic cardiopulmonary bypass: results of a randomized trial in infants
The Journal of Thoracic and Cardiovascular Surgery. 2003;126((6):):1765-74.
BACKGROUND We hypothesized that cognitive impairment and hemodynamic instability after infant cardiac surgery with cardiopulmonary bypass might be exacerbated by hemodilution. METHODS In a single-center randomized trial with blinded assessment of outcomes, we compared use of 2 hemodilution protocols during hypothermic cardiopulmonary bypass with infant cardiac surgery. The primary perioperative end point was lowest cardiac index in the first 24 hours postoperatively, and primary end points at age 1 year were scores on the Psychomotor Development Index and Mental Developmental Index of the Bayley Scales. RESULTS Among 147 subjects, 74 were assigned to the lower-hematocrit strategy (21. 5% +/- 2. 9%, mean +/- SD at onset of low-flow bypass) and 73 to the higher-hematocrit strategy (27. 8% +/- 3. 2%). In intent-to-treat analyses the lower-hematocrit group had lower nadirs of cardiac index (P =. 02), higher serum lactate levels 60 minutes after cardiopulmonary bypass (P =. 03), and a greater percentage increase in total body water on the first postoperative day (P =. 006). Blood product use and adverse events were similar in the 2 groups. At age 1 year (113 children), the lower-hematocrit group had worse scores on the Psychomotor Development Index (81. 9 +/- 15. 7 vs 89. 7 +/- 14. 7, P =. 008), as well as more Psychomotor Development Index scores at least 2 SDs below the population mean (16/56 [29%] vs 5/53 [9%], P =. 01). The groups had similar Mental Developmental Index scores and findings on neurologic examination. Inferences using hematocrit as a continuous variable were similar to those based on intent-to-treat analyses. CONCLUSIONS Hemodilution to a hematocrit level in wide use for cardiopulmonary bypass and thought to be safe is associated with adverse perioperative and developmental outcomes in infants.