Functional Performance of Different Venous Limb Options in Simulated Neonatal/Pediatric Cardiopulmonary Bypass Circuits

Abstract

ObjectiveHemodilution is a concern in cardiopulmonary bypass (CPB). Using a smaller dual tubing rather than a single larger inner diameter (ID) tubing in the venous limb to decrease prime volume has been a standard practice. The purpose of this study is to evaluate these tubing options.MethodsFour different CPB circuits primed with blood (hematocrit 30%) were investigated. Two setups were used with two circuits for each one. In Setup I, a neonatal oxygenator was connected to dual 3/16" ID venous limbs (Circuit A) or to a single 1/4" ID venous limb (Circuit B); and in Setup II, a pediatric oxygenator was connected to dual 1/4" ID venous limbs (Circuit C) or a single 3/8" ID venous limb (Circuit D). Trials were conducted at arterial flow rates of 500 ml/min up to 1500 ml/min (Setup I) and up to 3000 ml/min (Setup II), at 36°C and 28°C.ResultsCircuit B exhibited a higher venous flow rate than Circuit A, and Circuit D exhibited a higher venous flow rate than Circuit C, at both temperatures. Flow resistance was significantly higher in Circuits A and C than in Circuits B (P<0.001) and D (P<0.001), respectively.ConclusionA single 1/4" venous limb is better than dual 3/16" venous limbs at all flow rates, up to 1500 ml/min. Moreover, a single 3/8" venous limb is better than dual 1/4" venous limbs, up to 3000 ml/min. Our findings strongly suggest a revision of perfusion practice to include single venous limb circuits for CPB.

<p>Minimizing the need for transfusion in pediatric congenital heart surgery</p>

“…Here, the authors showed that improved drainage could be achieved with less prime volume for neonatal and infant patients when using the more common single venous line technique. 36 This result certainly appears to be a win-win outcome promoting the more common use of a single venous line in the CPB circuit.…”

“…39 Nevertheless, most clinicians agree that GME should be limited (and therefore VAVD levels) since the adult literature correlates outcomes negatively with increased GME numbers. 36,40,41 Ultrafiltration Ultrafiltration is another technique aimed at limiting hemodilution and transfusion requirements. Ultrafiltration is nearly universally utilized during pediatric CPB, and many centers use the technique after CPB as well.…”

The Brazilian Society for Cardiovascular Surgery (SBCCV) and Brazilian Society for Extracorporeal Circulation (SBCEC) Standards and Guidelines for Perfusion Practice

“…Perfusion practice during cardiovascular surgery is recognized in the international literature as a critical component to successful patient outcomes. Therefore, as medical societies, we have the responsibility to change our culture, our commercial practices, legislation, regulations and whatever else which involves our specialty which can improve patient outcomes [4,5] . The intent of our proposed standards and guidelines document is to provide a modern framework for the practice of cardiopulmonary bypass in Brazil that can maximize patient safety and outcomes.…”

Global outreach to improve the provision of cardiopulmonary bypass for patients with congenital heart disease

“…The first was a letter‐to‐the‐editor published in Artificial Organs in response to a multicenter evaluation of oxygenator devices the journal published . This was followed with a study evaluating bypass circuit venous limb options . These collaborative efforts are culminating in Latin America with a publication recommending phased adoption of the American Society of Extracorporeal Technology’s Standards and Guidelines in Brazil.…”