Mass transfer efficiency of a commercial hollow fibre oxygenator during six-hour in vitro perfusion with steady and with pulsatile blood flow

Detailed data about the behaviour of commercial membrane oxygenators with pulsatile blood flow are rarely available. This work deals with an experimental evaluation of the effects induced on gas transfer efficiency by pulsatile perfusion of a hollow fibre oxygenator (Monolyth Sorin Biomedica). The oxygenator was subjected to two in vitro trials both carried out with identical experimental protocols except for the flow type, steady and pulsatile. A roller pump with pulsatile module (Stockert Instrument) was used to generate both flow types. Three different mean blood flow rates (3.2, 4.0 and 4.8 Umin) were tested. The experiments lasting six hours were carried out using bovine blood with inlet conditions according to AAMI standard requirements. Blood samples were withdrawn every hour and the calculated gas transfer obtained in the two sessions were compared. The device proved to be well-designed for steady flow and to be liable to similar gas transfer performance when used in pulsatile conditions. Furthermore, the use of pulsatile flow rather than steady flow provided more consistent conditions and resulted in a higher eventual oxygen transfer efficiency (final mean difference = 6.2%, p < 0.05), proving to be able to avoid any performance decays. (Int J Artif Organs 1998; 21:97–106)