Comparison between D901 Lilliput 1 and Kids D100 neonatal oxygenators: toward bypass circuit miniaturization.

Progress in biomaterial technology and improvements in surgical and perfusion strategy ameliorated morbidity and mortality in pediatric cardiac surgery. In this study, we describe our clinical experience comparing performance of two neonatal oxygenators. From January 2002 to March 2011, 159 infants with less than 5 kg body weight underwent heart surgery. Ninety-four patients received a D901 Lilliput 1 oxygenator with standard bypass circuit (group A), while 65 received a D100 Kids with miniaturized bypass circuit (group B). Miniaturization consisted in shortened arterial, venous, cardioplegia, and pump-master lines. Priming composition consisted in Ringer's acetate solution with addition of albumin and blood, with target hematocrit of 24% or greater. In group B cardiopulmonary bypass (CPB) was vacuum-assisted and started with an empty venous line. Modified ultrafiltration and Cell-Saver blood infusion was routinely applied in both groups. Average ± standard deviation (SD) age at repair was 37 ± 38 days in group A and 59 ± 60 days in group B (P = 0.005). Average ± SD weight, height, and body surface area were 3.5 ± 0.7 kg, 52 ± 4 cm, and 0.22 ± 0.03 m(2) , respectively, in group A, and 3.7 ± 1 kg, 53 ± 5 cm, and 0.23 ± 0.02 m(2) , respectively, in group B (P = not significant [NS]). Male sex was predominant (55 vs. 58%, P = NS). Priming volume was 524 ± 67 mL (group A) and 337 ± 53 mL (group B) (P = 0.001). There were no statistical differences in hemoglobin at the start, during, and at the end of CPB, but group A required higher blood volume added to the prime (111 ± 33 vs. 93 ± 31 mL, P = 0.001). In group B, two surgical procedures were completed in total hemodilution. In group B, CPB time and aortic cross-clamp time were shorter than in group A (106 ± 52 vs. 142 ± 78 min and 44 ± 31 vs. 64 ± 31 min, respectively, P = 0.001). There were 16 hospital deaths in group A and 4 in group B (P = 0.04). Durations of mechanical ventilation and intensive care unit stay were 5.3 ± 3.2 vs. 4.1 ± 3.2 days (P = 0.02) and 6.5 ± 4.9 vs. 5.1 ± 3 days (P = 0.03), respectively. There were significant differences in inotropic score (1083 ± 1175 vs. 682 ± 938, P = 0.04) and blood postoperative transfusion (153 ± 226 vs. 90 ± 61 mL, P = 0.04). Twenty-seven patients in group A and 10 in group B presented with major adverse postoperative complications (P = 0.04). Use of neonatal oxygenators with low priming volume, associated with a miniaturized bypass circuit, seems to be a favorable strategy to decrease postoperative morbidity after cardiac surgery in neonates and infants.

Radiotherapy and risk of implantable cardioverter-defibrillator malfunctions: experimental data from direct exposure at increasing doses.

AIM: During radiotherapy, in patients with implantable cardioverter-defibrillators (ICDs) malfunctions are considered more likely if doses more than 2 Gy reach the ICD site; however, most malfunctions occur with high-energy (>10 MV) radiations, and the risk is less defined using 6-MV linear accelerators. The purpose of the study is to experimentally evaluate the occurrence of malfunctions in ICDs radiated with a 6-MV linear accelerator at increasing photon doses. METHODS: Thirty-two ICDs from all manufacturers (31 explanted and one demo) were evaluated; all devices with a sufficient battery charge underwent multiple radiations with a 6-MV photon beam reaching a cumulative dose at ICD site of 0.5, 1, 2, 3, 5 and 10 Gy and interrogated after every session. All antitachycardia therapies were left enabled; two ICDs were connected to a rhythm simulator (one simulating a complete atrioventricular block without ventricular activity) and visually monitored by external ECG and the ICD programmer during radiation. RESULTS: Thirteen ICDs were excluded before radiation because of battery depletion; after radiation up to the cumulative dose at the cardiac implantable electronic device site of 10 Gy, in the remaining 19 devices, programmation and battery charge remained unchanged and no switch to safety mode was observed; oversensing, pacing inhibition or inappropriate antitachycardia therapy were neither recorded nor visually observed during radiation. CONCLUSION: With a low-energy accelerator, neither malfunctions nor electromagnetic interferences were detected radiating the ICDs at doses usually reaching the ICD pocket during radiotherapy sessions. In this context, magnet application to avoid oversensing and inappropriate therapy seems, therefore, useless.