Development of simulated and ovine models of extracorporeal life support to improve understanding of circuit-host interactions.
BACKGROUND
Extracorporeal life support (ECLS) is a lifesaving technology that is being increasingly used in patients with severe cardiorespiratory failure. However, ECLS is not without risks. The biosynthetic interface between the patient and the circuit can significantly alter inflammation, coagulation, pharmacokinetics and disposition of trace elements. The relative contributions of the pump, disease and patient in propagating these alterations are difficult to quantify in critically ill patients with multiple organ failure.


OBJECTIVE
To design a model where the relevance of individual components could be assessed, in isolation and in combination.


METHODS
Four ECLS models were developed and tested - an in-vitro simulated ECLS circuit; and ECLS in healthy sheep, sheep with acute lung injury (ALI), and sheep with ALI together with transfusion of old or new blood.


METHODS
Successful design of in-vitro and in-vivo models.


RESULTS
We successfully conducted multiple experiments in the simulated circuits and ECLS runs in healthy and ALI sheep. We obtained preliminary data on inflammation, coagulation, histology, pharmacokinetics and trace element disposition during ECLS.


CONCLUSIONS
The establishment of in-vitro and in-vivo models provides a powerful means for enhancing knowledge of the pathophysiology associated with ECLS and identification of key factors likely to influence patient outcomes. A clearer description of the contribution of disease and therapeutic interventions may allow improved design of equipment, membranes, medicines and physiological goals for improved patient care.
Critical Care Research Group, Prince Charles Hospital, Brisbane, QLD, Australia. Kiran_shekar@health.qld.gov.au
Kiran
K
Shekar
Yoke L
YL
Fung
Sara
S
Diab
Daniel V
DV
Mullany
Charles I
CI
McDonald
Kimble R
KR
Dunster
Stephanie
S
Fisquet
David G
DG
Platts
David
D
Stewart
Steven C
SC
Wallis
Maree T
MT
Smith
Jason A
JA
Roberts
John F
JF
Fraser
D055371:Acute Lung Injury / Q000503:physiopathology* / Q000628:therapy*; D000818:Animals; D001803:Blood Transfusion / Q000295:instrumentation; D004195:Disease Models, Animal; D005112:Extracorporeal Circulation / Q000295:instrumentation; D006801:Humans; D008020:Life Support Care / Q000295:instrumentation; D008955:Models, Cardiovascular; D012756:Sheep