IL-6 and IL-8 levels after cardiopulmonary bypass are not affected by surface coating.

UNLABELLED: BACKGROUND.:Contact of blood with the surfaces of the cardiopulmonary bypass (CPB) circuit has been implicated as a cause of the inflammatory response. We undertook a prospective randomized trial of 200 pediatric patients, all with a calculated total bypass flow of less than 2.3 L/min (< 0.96 L/m2/min). METHODS: Patients were randomly assigned to 1 of 4 CPB groups: (1) Nonheparin-bonded circuit with no albumin preprime; (2) Nonheparin-bonded circuit with albumin preprime; (3) Heparin-bonded circuit with no albumin preprime; (4) Heparin-bonded circuit with albumin preprime. Measurements of cytokines, (interleukin [IL]-6, IL-8) and blood cell counts were made prebypass and 6 and 24 hours after institution of cardiopulmonary bypass. RESULTS: Analysis of variance showed no significant difference in any of the clinical or biochemical characteristics of the 4 groups. The interaction between heparin-bonded oxygenators and albumin preprime was not significant. No important differences in IL-6 or IL-8 concentrations were noted after CPB using either heparin or nonheparin-bonded oxygenators with albumin or albumin free preprime using two-way analysis of variance. CONCLUSIONS: Albumin preprime and heparin-bonding do not attenuate the inflammatory response component attributable to the concentration of these markers.

Centrifugal ventricular assist in children under 6 kg.

OBJECTIVE: The clinical application of centrifugal ventricular assist devices (VAD) has generally been limited to adults and large paediatric patients. In our experience neonates and small paediatric patients requiring ventricular support post-cardiopulmonary bypass are well supported by VAD. In this study we analyse our experience. METHODS: We have examined the records of our VAD patients who weighed less than 6 kg. Thirty-four patients, ranging in age from 2 to 258 days (median 60 days) and weight from 1.9 to 5.98 kg (median 3.7 kg), underwent 35 VAD procedures. One patient was supported on VAD twice. RESULTS: All patients had congenital heart lesions and were placed on VAD either because they could not be weaned from cardiopulmonary bypass after repair or palliation of the lesion (71.5%), or for support in the post-operative period due to refractory low cardiac output (28.5%). Twenty-two of the 35 VAD procedures (0.63, 95% CI: 0.45-0.78) resulted in successful weaning and decannulation, this was similar to the weaning probability for patients greater than 6 kg (P = 0.07). There were 10 late deaths in this group, with a 1-year KM survival of 0.31 (95% CI: 0.17-0.47). Most late deaths were related to irreversible cardiac disease processes as were the elective discontinuance of VAD outcomes. Neither weight, age, VAD duration, CPB duration, X clamp duration, univentricular anatomy or TGA anatomy predicted successful discharge from hospital (P > 0.05)--Weight P = 0.576; Age P = 0.532; VAD duration P = 0.181; CBP duration P = 0.549; X clamp duration P = 0.984; Univentricular anatomy P = 0.481; TGA anatomy P = 0.099. CONCLUSION: We believe centrifugal ventricular assist is a realistic option in very small patients who require post-cardiopulmonary bypass support. It is relatively easy to establish and manage, the results, although showing no factors predictive of successful discharge, are encouraging.

Bloodless open-heart surgery in infants and children.

Between October 1984 and January 1993, seven children of Jehovah's Witnesses underwent corrective open-heart surgery for congenital defects, on cardiopulmonary bypass (CPB). Age at surgery ranged from three months to 6.5 years, and weight ranged from 4.2 kg to 23.2 kg, with two children weighing less than 10 kg. The principal cardiac anomalies were tetralogy of Fallot (two), double outlet right ventricle (one), subaortic stenosis (one), transposition of the great arteries and ventricular septal defect (one), atrial septal defect and congenital heart block (one), and congenital mitral regurgitation (one). Hypothermic CPB was used in all seven operations with crystalloid priming of the extracorporeal circuit. CPB was based on our standard perfusion protocols. All surgical procedures were done without the use of blood or blood products. The mean preoperative haematocrit (Hct) was 40.9% (range 31.0-47.8%). The mean lowest intraoperative Hct was 17.3% (range 15.0-24.3%), whereas the immediate post-CPB Hct was 19.6% (range 15.3-24.0%). The Hct progressively increased to 29.2% (range 21.0-34.2%) on the first postoperative day, and 32.3% (range 24.2-38.3%) at the time of discharge. There was no hospital mortality, and the mean hospital stay was 10 days (8-13 days). We report the safe repair of complex open-heart surgery in children, without blood transfusion, even in small infants. The successful management of these patients requires meticulous attention to surgical and perfusion technique, and sound postoperative management.

Extracorporeal membrane oxygenation life support: a new approach.

The use of extracorporeal life support (ECLS) is considered in children who (1) have an acute life-threatening heart or lung disease, (2) are normal before the illness and are likely to be normal if they survive, and (3) have an 80% chance of death. Our use of a constrained vortex pump (CVP) offers a number of potential advantages compared to a roller pump. The circuit is designed to provide the capability of changing over to a new circuit while maintaining full support and is primed to match the biochemistry of the patient as closely as possible. Since May 1989 at the Royal Children's Hospital, Melbourne, Australia, we have provided ECLS to 30 neonates (20 of whom survived) and 22 children (eight of whom survived). ECLS is a useful technique for supporting patients who are unable to be adequately ventilated or oxygenated or who have an inadequate cardiac output.