Clinical evaluation of the Medtronic Maxima Plus membrane oxygenator

Abstract

The purpose of this study was to clinically evaluate the degree of improvement, if any, in the oxygen transfer performance of the recently released Medtronic Maxima Plus membrane oxygenator. The outside diameter of the hollow fibres was reduced, increasing the membrane surface area from 2.0 m2 to 2.3 m2 without altering the polycarbonate housing. Maximum extrapolated oxygen transfer of the Maxima Plus (444 ml O2/minute) was increased 23.68% when compared to the Maxima (359 ml O2/minute). When expressed per metre squared of membrane surface area, the Maxima Plus had an increase of 13.5 ml O2/m2/minute (7.24%) over the Maxima. Pressure drop across the Maxima Plus was within 3.5 mmHg of the Maxima over the range of clinical blood flows indicating that the fibre bundle packing density was not significantly altered. Oxygen transfer consistency, expressed as a function of the standard deviation of oxygenator performance index values, was not significantly different for the two oxygenators. We concluded that the improvement in total oxygen transfer was due to an increase in membrane surface area as well as enhanced transfer efficiency per metre squared. We believe that the improved oxygen transfer performance was accomplished without impacting significantly upon the other attributes of the oxygenator (e.g., pressure drop, consistency, priming volume).

A comparison of gaseous emboli release in five membrane oxygenators

“…A comparison of our blood path pressure data with that published by others shows close agreement. [31][32][33][34][35][36] If bubbles are neither trapped nor purged by the design of the oxygenator, nor appear at the outlet as a detectable bubble count, it must be assumed that these bubbles pass through the membrane to be eliminated via the gas path. It is assumed that the TMP is a factor in moving these bubbles through the membrane from the blood path to the gas path.…”

Clinical oxygen transfer comparison of the Terumo Capiox SX18 and SX25 membrane oxygenators

“…The purpose of this current study is to apply our previously described membrane oxygenator evaluation techniques 3,4 to compare the two devices with regard to: (1) their oxygen transfer slopes (OTS);…”