ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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Comparative Study
Postoperative extracorporeal life support in pediatric cardiac surgery: recent results.
We retrospectively reviewed the files of 19 extracorporeal life support (ECLS) applications performed after cardiac surgery in 15 patients from January 2002 to December 2004. We placed 16 arteriovenous ECLS applications with oxygenator, 2 venovenous ECLS applications with oxygenator, and 1 biventricular ECLS application without oxygenator (graft dysfunction after heart transplant). Mean age was 4.9 +/- 7 years (median 5.9 months, range 11 days to 21 years). ⋯ No survivor presented obvious neurologic damage. Specific morbidity included reentry for bleeding, multiple transfusions, and mediastinitis. These results support early placement of ECLS in children whenever a severe postoperative hemodynamic or respiratory failure, refractory to medical treatment, is present.
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Comparative Study
In vitro evaluation of the performance of Korean pulsatile ECLS (T-PLS) using precise quantification of pressure-flow waveforms.
The Twin-Pulse Life Support System (T-PLS) is a novel pulsatile extracorporeal life support system developed in Korea. It has been reported that the T-PLS achieves higher levels of tissue perfusion of the kidney during short-term extracorporeal circulation and provides more blood flow to coronary artery than nonpulsatile blood pumps. However, these results lack pulsatility quantifications and thus make it hard to analyze the effects of pulsatility upon hemodynamic performance. ⋯ The pulsatility performances are different according to circuit setups. However, the parallel A circuit could achieve higher pump output and generate adequate pulsatility level. Thus, the parallel A circuit is suggested as the optimal configuration in T-PLS applications.
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Comparative Study
Precise quantification of pulsatility is a necessity for direct comparisons of six different pediatric heart-lung machines in a neonatal CPB model.
Generation of pulsatile flow depends on an energy gradient. Surplus hemodynamic energy (SHE) is the extra hemodynamic energy generated by a pulsatile device when the adequate pulsatility is achieved. The objective of this study was to precisely quantify and compare pressure-flow waveforms in terms of surplus hemodynamic energy levels of six different pediatric heart-lung machines in a neonatal piglet model during cardiopulmonary bypass (CPB) procedures with deep hypothermic circulatory arrest (DHCA). ⋯ The PPP produced the greatest surplus hemodynamic energy. Most of the pediatric pulsatile pumps (except Mast-PR) generated significant surplus hemodynamic energy. None of the nonpulsatile roller pumps generated adequate surplus hemodynamic energy.
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The Department of Health and Human Services, at the direction of Congress, has recently begun to address concerns regarding the development of medical devices designed specifically for the pediatric population, including devices for pediatric mechanical circulatory support, as evidenced by the National Institutes of Health's (NIH) funding of several development contracts. Food and Drug Administration (FDA) approval for marketing of these devices will typically follow either of two regulatory pathways: the Humanitarian Device Exemption (HDE) or the Premarket Application (PMA). An HDE is limited both in the extent of clinical use and economic benefit to the manufacturer, but does not require data derived from a clinical trial for market approval. ⋯ In addition, an HDE requires a demonstration of probable benefit, whereas a PMA requires a demonstration of a reasonable assurance of effectiveness. The evidence that can be used to support an HDE or a PMA approval may include both preclinical and clinical data. Types of preclinical tests needed depend upon the device design and its intended use, because circulatory support devices are all unique.
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Comparative Study
Experience with extracorporeal life support in pediatric patients after cardiac surgery.
Extracorporeal life support (ECLS) had been successfully used in neonatal respiratory failure, but cardiac ECLS has been used increasingly in recent years. The purpose of this study was to review our experience in pediatric patients supported by ECLS for postoperative circulatory failure and to analyze the factors associated with mortality. Between January 1999 and December 2004, 68 pediatric patients (< 18 years old) who received ECLS within 7 days after cardiac surgery at the National Taiwan University Hospital were included in this study. ⋯ After ECLS initiation, the lowest lactate levels on the second to fourth days were lower in survivors than in nonsurvivors (2.4 vs. 3.3 mmol/L, p < 0.05). There was a trend toward a better survival in the most recent 2 years in comparison with the previous 4 years (47.6% vs. 25.5%, p = 0.07), although this trend did not reach statistical significance. In conclusion, nonbiventricular physiology, acute renal failure, and high blood lactate levels after ECLS increased the risk of mortality for pediatric patients requiring ECLS for postoperative cardiac support.