G . S . Matte et al .: J Extra Corpor Technol 2024 , 56 , 216 – 224 217
Table 1 . Example of a confirmation of oxygenator failure algorithm and preparation for an oxygenator change-out .
Work with a backup perfusionist on the following :
1 . Assess arterial and venous lines for color difference . Confirm in-line gas values with lab specimen if possible . 2 . Confirm sweep gas is on with the proper source ( and blender settings if in use ). 3 . Confirm proper ventilation-to-perfusion ( V / Q ) ratio . 4 . Confirm integrity of sweep gas system all the way to the oxygenator exhaust port ( vaporizer cap sealed – may bypass vaporizer altogether / turn off vaporizer ). Discern proper function by tactile and audible means ( sweep gas line to oxygenator creates pressure when disconnected from oxygenator and temporarily blocked ). 5 . Confirm function of flow meter ( if in use ). 6 . Confirm proper blood flow ( appropriate pump arterial line / system pressure and appropriate patient arterial pressure , correct tubing size selected on arterial controller , flow probe value verified , closure of recirculation / prime lines ). 7 . Change to 100 % oxygen if not already on that source ( may change to stand-alone E-cylinder with flow meter to rule out issues with normal sweep gas system ). 8 . Consider whether the oxygenator may be “ wetted out ”. Use manufacturer recommended guidelines for treatment . – Terumo FX-05 : Increase sweep rate to sigh oxygenator ; max sweep of 5 LPM for 10 s ( do not repeat ). – Sorin D101 : Increase sweep rate to sigh oxygenator ; max V / Q of 4:1 for 10 min . – Terumo FX15-30 : Increase sweep rate to sigh oxygenator ; max sweep of 15 LPM for 10 s ( do not repeat ). – Terumo FX-25 : Increase sweep rate to sigh oxygenator ; max sweep of 20 LPM for 10 s ( do not repeat ). 9 . Consult with the anesthesiologist to confirm proper muscle relaxants / anesthesia are in use ( check reported VO 2 value ). Consider malignant hyperthermia if the CO 2 is significantly elevated with a low SvO 2 ( if an isoflurane source is in the sweep gas system ). 10 . Request second perfusionist to clear-prime a replacement oxygenator in the pump room with quick-connect tubing and connectors attached to replacement device . 11 . Inform surgeon of findings and discuss action plan ( define lowest acceptable PaO 2 before change-out ). If change-out required , clarify if it will be with a relatively warm and ventilated patient that is ejecting versus hypothermic with circulatory arrest .
by the manufacturer , is maintained through the device . The anesthesiologist should also be consulted for depth of anesthesia and muscle relaxation .
Once primary oxygenator failure has been verified , the clinical team must decide on an intervention , or series of interventions , with timing dependent on the PaO 2 , SaO 2 , patient temperature , surgical progress , and native circulatory status . Table 2 lists recommended steps for a traditional oxygenator change-out procedure , which requires an interruption of cardiopulmonary support [ 5 , 7 ]. This was the internal guidance we had for an oxygenator change-out before our most recent case of oxygenator failure .
The most recent case caused us to reconsider all options for such an emergency . This report summarizes intervention options for oxygenator-reservoir device failure along with our team ’ s updated oxygenator failure intervention algorithm . It also includes our bypass circuit framework that allows a quick and efficient intervention to provide venous piggyback oxygenation , which may serve as a temporizing measure with or without an eventual oxygenator change-out . A programmatic overview of CPB oxygenator issues and a recent case are also discussed . An Institutional Review Board ( IRB ) waiver was granted for this manuscript ( IRB-P00049148 ).
Intervention options for oxygenator-reservoir failure during CPB
Perfusionists have options to consider when an oxygenator shows signs of failure during cardiopulmonary bypass . Groom et al . reported on the parallel replacement of an oxygenator not transferring oxygen ( PRONTO ) technique in 2002 [ 11 ]. This technique is seemingly ideal because a definitive replacement may be performed without interrupting surgical progress and without circulatory arrest . Over twenty years have passed since their article was published , yet based on anecdotal evidence , the technique has not garnered widespread adoption . Not all perfusion programs are even aware of the option [ 3 ]. Programs familiar with the PRONTO technique may be hesitant to adopt it considering the custom tubing pack changes required and additional Y-connections pre and post- the primary oxygenator for all setups . Additional connectors and flow paths on 100 % of pump circuits introduce areas of risk that must be considered against the rare occurrence of true oxygenator failure requiring replacement during CPB . Furthermore , unlike in 2002 , when the PRONTO technique article was published , the post-oxygenator connection is now commonly post-arterial line filter ( ALF ) with the advent of integrated ALFs . That adds another concern in that there is no longer a final filter between the intervention site in the circuit and the patient . Grist [ 1 ] andWillcox [ 12 ] have both published endorsements for the PRONTO technique in the past few years for good reason ; teams must be prepared to deal with oxygenator failure for optimal patient outcomes and patient safety . While an oxygenator change-out procedure may still be the gold standard , alternative temporizing measures exist that , in select cases , can afford time to the clinical team and even obviate the need for an oxygenator change-out . These measures are of critical consideration for programs not electing to include connections for a PRONTO setup .
Figure 1 shows an internally developed document summarizing our team ’ s experience and thought-framework for options to treat confirmed oxygenator failure . Key advantages and disadvantages of each method are included . A primary consideration that must be taken into account during the assessment of declining oxygenator function is whether there is a