Topic: Retrospective or Prospective Cohort Study or Case Series
Thakore, Aneesh1; Cavayas, Yiorgos Alexandros1; Fan, Eddy1
1. Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
Introduction
By completely taking over gas exchange, venovenous extracorporeal membrane oxygenation (VV-ECMO) can facilitate “ultra”-protective ventilation in patients with respiratory failure, thereby potentially preventing further injury. There are, however, limited data available to guide mechanical ventilation (MV) during VV-ECMO.
Objectives
- To describe the MV parameters used in patients on VV-ECMO in our institution and to assess the association between MV parameters and patient outcomes.
- To assess whether patients placed on VV-ECMO, as compared to conventional MV, are exposed to less injurious ventilation, as measured by mechanical power.
- To assess whether any differences in mechanical power between the two groups is associated with patient outcomes, including mortality and organ dysfunction/injury.
We conducted a retrospective cohort study of all consecutive adult patients supported with VV-ECMO at the Toronto General Hospital between January 1, 2014 and January 30, 2019, and propensity score matched controls receiving conventional MV. Data was obtained from the Toronto Intensive Care Observational Registry (iCORE) and supplemented with data extracted from electronic patient records. MV parameters on the first and last day of ECMO, and outcomes were described using median (interquartile range). Wilcoxon signed-rank tests were used to compare the MV parameters of the first and last day of ECMO support, and the MV parameters of survivors and non-survivors. A Spearman correlation was used to assess the relationship between compliance and ECMO-free days at 28 days. A multivariable logistic regression analysis will be used to calculate the propensity score, which will be used to match ARDS patients managed with VV-ECMO and those managed without VV-ECMO using a 1:1 matching procedure without replacement and a caliper width of 0.2. Comparisons of mechanical power and mortality between VV-ECMO managed patients and their propensity score matched counterparts will be done using Wilcoxon signed-rank tests and multivariate logistic regression analysis, respectively.
Preliminary Results
Of the 74 patients included, 61% survived to ICU discharge, with a median of 6 (0-18) ECMO-free days. The median (IQR) MV parameters on Day 1 of ECMO were as follows: peak inspiratory pressure 21 (20-25) cmH2O, positive end-expiratory pressures (PEEP) 10 (10-10) cmH2O, driving pressure 11 (10-14) cmH2O, respiratory rate 13 (10-18), tidal volume 2.8 (1.8-4.1) mL/kg, FiO2 0.5 (0.4-0.5), dynamic compliance 14 (8-22) mL/cmH2O. On the last day of ECMO, there were significant increases in respiratory rate to 18 (15-26), tidal volume to 5.4 (4.2-7.6) mL/kg, and the compliance to 24 (16-36) mL/cmH2O. There were no significant differences in Day 1 parameters between survivors and non-survivors. However, tidal volume and compliance increased significantly over time in the survivors (p=0.001). The change in compliance correlated significantly with ECMO-free days (rho=0.6; p=0.001).
Conclusions
In our institution, “ultra”-protective MV parameters were commonly initiated with VV-ECMO and no Day 1 MV parameter differed significantly between survivors and non-survivors. The propensity score analysis will provide additional insight on whether VV-ECMO allows a reduction in mechanical power and if this results in improved clinical outcomes.
No references
Topic: Retrospective or Prospective Cohort Study or Case Series
Thakore, Aneesh1; Cavayas, Yiorgos Alexandros1; Fan, Eddy1
1. Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
Introduction
By completely taking over gas exchange, venovenous extracorporeal membrane oxygenation (VV-ECMO) can facilitate “ultra”-protective ventilation in patients with respiratory failure, thereby potentially preventing further injury. There are, however, limited data available to guide mechanical ventilation (MV) during VV-ECMO.
Objectives
- To describe the MV parameters used in patients on VV-ECMO in our institution and to assess the association between MV parameters and patient outcomes.
- To assess whether patients placed on VV-ECMO, as compared to conventional MV, are exposed to less injurious ventilation, as measured by mechanical power.
- To assess whether any differences in mechanical power between the two groups is associated with patient outcomes, including mortality and organ dysfunction/injury.
We conducted a retrospective cohort study of all consecutive adult patients supported with VV-ECMO at the Toronto General Hospital between January 1, 2014 and January 30, 2019, and propensity score matched controls receiving conventional MV. Data was obtained from the Toronto Intensive Care Observational Registry (iCORE) and supplemented with data extracted from electronic patient records. MV parameters on the first and last day of ECMO, and outcomes were described using median (interquartile range). Wilcoxon signed-rank tests were used to compare the MV parameters of the first and last day of ECMO support, and the MV parameters of survivors and non-survivors. A Spearman correlation was used to assess the relationship between compliance and ECMO-free days at 28 days. A multivariable logistic regression analysis will be used to calculate the propensity score, which will be used to match ARDS patients managed with VV-ECMO and those managed without VV-ECMO using a 1:1 matching procedure without replacement and a caliper width of 0.2. Comparisons of mechanical power and mortality between VV-ECMO managed patients and their propensity score matched counterparts will be done using Wilcoxon signed-rank tests and multivariate logistic regression analysis, respectively.
Preliminary Results
Of the 74 patients included, 61% survived to ICU discharge, with a median of 6 (0-18) ECMO-free days. The median (IQR) MV parameters on Day 1 of ECMO were as follows: peak inspiratory pressure 21 (20-25) cmH2O, positive end-expiratory pressures (PEEP) 10 (10-10) cmH2O, driving pressure 11 (10-14) cmH2O, respiratory rate 13 (10-18), tidal volume 2.8 (1.8-4.1) mL/kg, FiO2 0.5 (0.4-0.5), dynamic compliance 14 (8-22) mL/cmH2O. On the last day of ECMO, there were significant increases in respiratory rate to 18 (15-26), tidal volume to 5.4 (4.2-7.6) mL/kg, and the compliance to 24 (16-36) mL/cmH2O. There were no significant differences in Day 1 parameters between survivors and non-survivors. However, tidal volume and compliance increased significantly over time in the survivors (p=0.001). The change in compliance correlated significantly with ECMO-free days (rho=0.6; p=0.001).
Conclusions
In our institution, “ultra”-protective MV parameters were commonly initiated with VV-ECMO and no Day 1 MV parameter differed significantly between survivors and non-survivors. The propensity score analysis will provide additional insight on whether VV-ECMO allows a reduction in mechanical power and if this results in improved clinical outcomes.
No references