Factors associated with blood oxygen partial pressure and carbon dioxide partial pressure regulation during respiratory extracorporeal membrane oxygenation support: data from a swine model

Abstract

ObjectiveThe aim of this study was to explore the factors associated with blood oxygen partial pressure and carbon dioxide partial pressure.MethodsThe factors associated with oxygen - and carbon dioxide regulation were investigated in an apneic pig model under veno-venous extracorporeal membrane oxygenation support. A predefined sequence of blood and sweep flows was tested.ResultsOxygenation was mainly associated with extracorporeal membrane oxygenation blood flow (beta coefficient = 0.036mmHg/mL/min), cardiac output (beta coefficient = -11.970mmHg/L/min) and pulmonary shunting (beta coefficient = -0.232mmHg/%). Furthermore, the initial oxygen partial pressure and carbon dioxide partial pressure measurements were also associated with oxygenation, with beta coefficients of 0.160 and 0.442mmHg/mmHg, respectively. Carbon dioxide partial pressure was associated with cardiac output (beta coefficient = 3.578mmHg/L/min), sweep gas flow (beta coefficient = -2.635mmHg/L/min), temperature (beta coefficient = 4.514mmHg/ºC), initial pH (beta coefficient = -66.065mmHg/0.01 unit) and hemoglobin (beta coefficient = 6.635mmHg/g/dL).ConclusionIn conclusion, elevations in blood and sweep gas flows in an apneic veno-venous extracorporeal membrane oxygenation model resulted in an increase in oxygen partial pressure and a reduction in carbon dioxide partial pressure 2, respectively. Furthermore, without the possibility of causal inference, oxygen partial pressure was negatively associated with pulmonary shunting and cardiac output, and carbon dioxide partial pressure was positively associated with cardiac output, core temperature and initial hemoglobin.

Determinants of Arterial Pressure of Oxygen and Carbon Dioxide in Patients Supported by Veno-Arterial ECMO

“…The importance of the sweep gas flow rate has already been described for VV ECMO [ 11 ]. The same study and various others have reported that Q EC and FiO 2 have little effect on CO 2 removal [ 11 , 27 ], but this is inconsistent with other experimental studies [ 13 ]. Contrary to oxygenation, time had no impact on membrane CO 2 removal, at least during the first 48 h. This finding is explained by the high diffusion coefficient of CO 2 .…”

“…We included only patients on femoro-femoral VA ECMO. Some important cardio-respiratory parameters were not available for the analysis, such as the native cardiac output for all patients or the native respiratory function and pulmonary shunt [ 27 ]. Furthermore, we did not evaluate middle and long-term lung function or patient outcomes.…”

Apnea test for the diagnosis of brain death in a patient undergoing extracorporeal membrane oxygenation

“…( 1 ) Although the situation is challenging given the diagnosis of BD, these support devices become interesting alternatives for maintaining the viability of organs targeted for transplantation. ( 3 , 5 , 6 )…”

Extracorporeal respiratory support in adult patients

“…As a result, arterial blood oxygenation improves with increases in blood flow through the ECMO system despite the diffusion-determined loss of efficiency. 24 The sweep gas flow has little impact on oxygen transfer. 25 …”