Clinical evaluation of the Bentley Univox membrane oxygenator

This paper reports a clinical evaluation of Bentley's new Univox membrane oxygenator (Bentley Laboratories, Irvine, California). In this new device, the blood flow path is outside the fibre, the incorporated heat exchanger consists of a 22-channel stainless-steel bellows, and the polypropylene fibres are woven into fibre ribbons and wound into each of the bellows channels. In this way, heat and gas transfers take place simultaneously. The priming volume has been reduced to 220ml and the membrane has an effective surface area of 1.6m2. A BMR 1900 collapsible reservoir (Bentley Laboratories, Irvine, California) was used as a venous reservoir. Ten consenting patients undergoing elective coronary artery bypass surgery were perfused with this new oxygenator. BSA was between 1.7 and 2.11 m 2; mean BSA was 1.81. Minimum priming was 1200ml. The blood-gas results were all within or close to the normal range used in our institution. Acid-base management was performed using alpha-stat regulation and no problems occurred in this series of patients. Average pO2 was 155mmHg±53 with a mean O2 transfer of 90.7ml and a maximum of 185ml. The heat exchange performance was very good, with a mean coefficient of heat exchange of 0.54±0.11 and a maximum of 0.87.

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A clinical evaluation of platelet function, haemolysis and oxygen transfer during cardiopulmonary bypass comparing the Quantum HF-6700 to the HF-5700 hollow fibre membrane oxygenator

Perfusion ◽

10.1177/026765910001500602 ◽

2000 ◽

Vol 15 (6) ◽

pp. 479-484 ◽

Cited By ~ 6

Author(s):

A O Chukwuemeka ◽

M RJ Turtle ◽

U H Trivedi ◽

G E Venn ◽

D J Chambers

Keyword(s):

Cardiopulmonary Bypass ◽

Platelet Function ◽

Clinical Evaluation ◽

Oxygen Transfer ◽

Artery Bypass ◽

Membrane Surface ◽

Platelet Activating Factor ◽

Hollow Fibre ◽

Priming Volume ◽

First Time

The continued improvement of oxygenators is an important aspect of patient safety during cardiopulmonary bypass (CPB). The purpose of this study was to compare the Bard William Harvey HF-5700 oxygenator to the upgraded Bard Quantum HF-6700, which has recently been introduced into clinical practice. No clinical evaluation of this device has been published to date. The two oxygenators differ principally in that the Quantum has a smaller priming volume, achieved at the expense of a smaller membrane surface area which could result in sub-optimal gas exchange characteristics, increased haemolysis and increased platelet dysfunction during CPB. Twenty adult patients undergoing elective, first time coronary artery bypass grafting (CABG) were randomly assigned either to the HF-5700 ( n=10) or to the HF-6700 ( n=10) group. One patient underwent mitral valve repair in addition to CABG and was excluded from further study. There were no statistically significant differences in either preoperative or operative parameters between the two groups. Samples were obtained at the start of CPB, at 30 min, 60 min, at the end of CPB and at 1 h following termination of CPB. No significant differences between the two groups were found in oxygen transfer, haemolysis (plasma haptoglobin levels) or platelet function (a novel platelet activating factor (PAF)-induced platelet activation test) at any of the time points during CPB. It was concluded that the Quantum HF-6700 matches the HF-5700 for the parameters studied, whilst having the advantage of requiring a smaller priming volume.

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