Elevated red cell distribution width is associated with delayed postoperative recovery after correction of Tetralogy of Fallot

OBJECTIVE: To study the impact of red cell distribution width (RDW) on postoperative recovery after correction of Tetralogy of Fallot (TOF). BACKGROUND: Increased RDW indicates dysregulated erythropoiesis and predicts survival in critical illnesses that include idiopathic pulmonary artery hypertension and chronic heart failure. Myocardial injury and oxidative stress induced by cardiopulmonary bypass potentially contribute to prolonged recovery in post TOF repair patients. MATERIALS AND METHODS: Retrospective analysis of data on 94 consecutive children with TOF undergoing corrective repair (January 2010-March 2011) was done. RDW was higher for the study population when compared to acyanotic patients with ventricular septal defect (17.7 ± 3.7 vs. 16.2 ± 4.2; P < 0.001). The mean RDW obtained from 100 separate age-, sex-, and weight-matched TOF patients (17.8) was chosen as a cut-off. Of 93 survivors (median age: 12 (4-204) months, weight: 8.6 (3.2-70) kg), 29 patients with higher RDW (> 17.8) had a longer ICU stay (155.6 ± 71.3 vs. 122.4 ± 61.3 hours, P = 0.02), hospital stay (18.6 ± 10.5 days vs. 13.4 ± 6.5 days, P = 0.01), ventilation time (57.9 ± 41.6 vs. 38.3 ± 30.8 hours, P = 0.01), and more surgical site infection (24.1% vs. 6.2%, P = 0.01). On multivariate analysis only elevated RDW (other variables included age, weight, hemoglobin, hematocrit, and surgical support times) showed a significant association with hospital stay. CONCLUSIONS: Elevated RDW appears to be associated with prolonged recovery after TOF repair, the precise underlying mechanisms are worth investigating.