Title
Controlled administration and hperoxygenation of cold preservation solution in controlled DCD donors undergoing abdominal-normothermic regional perfusion
First and Presenting author
Marta Velia Antonini MSc m.antonini@unibo.it
Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Intensive Care Unit, Bufalini Hospital, AUSL della Romagna, Cesena, Italy
Co-authors
Alessandro Circelli MD Intensive Care Unit, Bufalini Hospital, AUSL della Romagna, Cesena, Italy
Gaetano La Manna Prof Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy AND Nephrology, Dialysis and Kidney Transplant Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
Antonio Siniscalchi Prof Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy AND Terapia intensiva Post Chirurgica e dei trapianti di organi addominali ~ Bologna
Erika Cordella MD Emilia-Romagna Transplant Reference Centre, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
Enrico Prosperi Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Guido Fallani Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Chiara Bonatti Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Alberto Stocco Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Giorgia Radi Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Maria Cristina Morelli Medicina Interna per il trattamento delle gravi insufficienze d’organo ~ Bologna AND Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
Matteo Cescon Prof Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy AND General Surgery and Transplant Unit, IRCCS, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
Matteo Ravaioli Prof Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy AND General Surgery and Transplant Unit, IRCCS, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
Introduction
The organs of donors undergoing circulatory determination of death (DCDDs) usually experience a period of static cold storage. SCS precedes further evaluation and reconditioning through ex-situ machine perfusion, or direct transplantation. This hypothermic preservation period, aimed at reducing metabolic demands, is initiated in-situ, through both topic and intravascular cooling. The latter is induced through the administration of a high volume of cold preservation solution (CPS) by gravity. CPS displaces the blood from the splanchnic circulation, and provides a perfusate decreasing the potential damages of ischemia and cooling.
In DCDDs, in the setting of abdominal normothermic regional perfusion (A-NRP), the extracorporeal circuit and cannulae may be employed to infuse and oxygenate CPS, ensuring a controlled flow and increasing dissolved oxygen (O2) in the blood-free perfusate.
Methods
We aimed to assess feasibility, safety and effectiveness of a controlled administration of CPS through the NRP circuit and through the arterial cannula, and of its oxygenation through the membrane lung (ML) in DCDDs undergoing A-NRP.
Immediately after NRP, CPS was actively administered through the circuit accompanied by a flow of O2 to the ML. The CPS flow was set at 400 ml/min if body surface area ≤1.7 and 500 if >1.7, with 1:1 CPS to sweep gas flow ratio. The drainage cannula was used to vent the venous system. The perfusion strategy is described in figure 1 A-D.
We measured the CPS partial pressure of O2 (PCPSO2) at the beginning and at the end of its administration. The circuit was strictly monitored to assess for potential procedure related complications.
Results
We implemented this approach in 29 DCDDs undergoing A-NRP. In 13 donors oxygen was added to the CPS (table), achieving a median PCPSO2 of 648.5 mm Hg (IQR 76.5). Hyperoxygenation was stable throughout CPS administration (5-8 L).
Mean and median PCPSO2 were consistently above 600 mm Hg for all Celsior® and IGL-1® solutions samples. Mean PCPSO2 was 500 mmHg with Belzer UW®, administered once. Anyway, this is still compliant with hyperoxygenation definition. Mean/median PCPSO2 were consistently above 600 mmHg for all the circuits, independently from these integrating polypropylene (PP) or polymethylpentene (PMP) MLs.
PCPSO2 in control samples from bags before administration was below 100 mm Hg. Median PCPSO2 in samples from controls infused through the circuit without gas flow (but passing through the ML fibers) was 187 mmHg (IQR 45).
We report one case of minor air entrance, managed without interrupting perfusion.
Conclusions
The infusion of an oxygenated CPS through the NRP circuit could be feasible and effective in ensuring a consistent and controlled CPS flow, inducing a fast SCS initiation. Moreover, the provision of a flow of O2 through the ML during CPS infusion may consistently and significantly enhance the amount of dissolved oxygen. The oxygenation of the cold blood-free perfusate may improve tissue oxygenation, potentially providing a substrate for the organs during cold ischemia. This approach requires the same equipment used for NRP, with no increase in procedure related costs.
As the manipulation of the drainage limb of the circuit increases the risk for disruption and air entrance, extreme caution should be exerted to prevent, promptly recognize and manage this complication. If a small venous cannula is used for NRP, parallel venting through the right atrium should be considered, to avoid venous congestion with fast CPS infusion.
