Impact of Vacuum-Assisted Venous Drainage on Forward Flow in Simulated Pediatric Cardiopulmonary Bypass Circuits Utilizing a Centrifugal Arterial Pump Head.

Daniel Peres Guimarães,Marcelo B Jatene,Valéria Camargo Policarpo,Idagene Cestari,Gregory Matte,Luiz Fernando Caneo,Priscila S Costa,Luciana P Carletto,Matheus H C Miranda,Fabio B Jatene,Ana Vitória C X Castro

doi:10.21470/1678-9741-2019-0311

Daniel Peres Guimarães, Marcelo B Jatene + Show 9 more

Open Access

https://doi.org/10.21470/1678-9741-2019-0311

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Abstract

ObjectiveTo analyze the impact of vacuum-assisted venous drainage (VAVD) on arterial pump flow in a simulated pediatric cardiopulmonary bypass circuit utilizing a centrifugal pump (CP) with an external arterial filter.MethodsThe simulation circuit consisted of a Quadrox-I Pediatric oxygenator, a Rotaflow CP (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set primed with Lactated Ringer's solution and packed red blood cells. Venous line pressure, reservoir pressure, and arterial flow were measured with VAVD turned off to record baseline values. Four other conditions were tested with progressively higher vacuum pressures (-20, -40, -60, and -80 mmHg) applied to the baseline cardiotomy pressure. An arterial filter was placed into the circuit and arterial flow was measured with the purge line in both open and closed positions. These trials were repeated at set arterial flow rates of 1500, 2000, and 2500 mL/min.ResultsThe use of progressively higher vacuum caused a reduction in effective arterial flow from 1490±0.00 to 590±0.00, from 2020±0.01 to 1220±0.00, and from 2490±0.0 to 1830±0.01 mL/min. Effective forward flow decreased with increased levels of VAVD.ConclusionThe use of VAVD reduces arterial flow when a CP is used as the main arterial pump. The reduction in the forward arterial flow increases as the vacuum level increases. The loss of forward flow is further reduced when the arterial filter purge line is kept in the recommended open position.An independent flow probe is essential to monitor pump flow during cardiopulmonary bypass.

Highlights

Traditional gravity siphon drainage with small size cannulae and tubings may provide insufficient blood return to the cardiotomy reservoir and compromise effective forward flow and tissue perfusion[1,2]
The use of vacuum-assisted venous drainage (VAVD) reduces arterial flow when a centrifugal pump (CP) is used as the main arterial pump
The mean Venous limb pressure (VLP) (P1), mean venous reservoir pressure (P2), effective forward flow, and purge line shunt flow are shown in Table 1, with the arterial line filter purge turned off

Summary

Introduction

Traditional gravity siphon drainage with small size cannulae and tubings may provide insufficient blood return to the cardiotomy reservoir and compromise effective forward flow and tissue perfusion[1,2]. Assisted venous drainage techniques such as kinetic-assisted venous drainage (KAVD) and vacuum-assisted venous drainage (VAVD) are used to improve venous return[3]. KAVD uses a centrifugal pump (CP) placed in the venous line to generate negative venous line pressure while VAVD involves application of a constant vacuum pressure to the airtight cardiotomy venous reservoir (CVR). VAVD is largely used in minimally invasive surgery, and commonly in pediatric cardiac surgery, with small circuits and/or small cannulae[3].

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