A novel strategy for preoxygenation in hypoxaemic patients, adding HFNC for apnoeic oxygenation to NIV prior to orotracheal intubation, may be more effective in reducing the severity of oxygen desaturation than the reference method using NIV alone.
Background
The bicaval drainage under veno-venous extracorporeal membrane oxygenation (VV ECMO) was compared in present experimental study to the inferior caval drainage in terms of systemic oxygenation.
Method
Two mathematical models were built to simulate the inferior vena cava-to-right atrium (IVC → RA) route and the bicaval drainage-to-right atrium return (IVC + SVC → RA) route using the following parameters: cardiac output (QC), IVC flow/QC ratio, venous oxygen saturation, extracorporeal pump flow (QEC), and pulmonary shunt (PULM-Shunt) to obtain pulmonary artery oxygen saturation (SPAO2) and systemic blood oxygen saturation (SaO2).
Results
With the IVC → RA route, SPAO2 and SaO2 increased linearly with QEC/QC until the threshold of the IVC flow/QC ratio, beyond which the increase in SPAO2 reached a plateau. With the IVC + SVC → RA route, SPAO2 and SaO2 increased linearly with QEC/QC until 100% with QEC/QC = 1. The difference in required QEC/QC between the two routes was all the higher as SaO2 target or PULM-Shunt were high, and occurred all the earlier as PULM-Shunt were high. The required QEC between the two routes could differ from 1.0 L/min (QC = 5 L/min) to 1.5 L/min (QC = 8 L/min) for SaO2 target = 90%. Corresponding differences of QEC for SaO2 target = 94% were 4.7 L/min and 7.9 L/min, respectively.
Conclusion
Bicaval drainage under ECMO via the IVC + SVC → RA route gave a superior systemic oxygenation performance when both QEC/QC and pulmonary shunt were high. The VV-V ECMO configuration (IVC + SVC → RA route) might be an attractive rescue strategy in case of refractory hypoxaemia under VV ECMO.
Background:The aim of this study was to assess the interdependence of extracorporeal blood flow (Qec) and gas flow (GF) in predicting CO 2 removal and reduction of minute mechanical ventilation under extracorporeal respiratory support.Methods: All patients who benefited from V-V ECMO and high-flow ECCO 2 R in our intensive care unit over a period of 18 months were included. CO 2 removal was calculated from inlet/outlet blood port gases during the first 7 days of oxygenator use. The relationship between the Qec × GF product (named decarboxylation index and expressed in L 2 /min 2 ) and CO 2 removal or expired minute mechanical ventilation reduction ( EC MV ratio) was studied using linear regression models.Results: Eighteen patients were analyzed, corresponding to 24 oxygenators and 261 datasets. CO 2 removal was 393 ml/min (IQR, 310-526) for 1.8 m 2 oxygenators and 179 ml/min (IQR, 165-235) for 1.3 m 2 oxygenators. The decarboxylation index was associated linearly with CO 2 removal (R 2 = 0.62 and R 2 = 0.77 for the two oxygenators, respectively) and EC MV ratio (R 2 = 0.72 and R 2 = 0.62, respectively). The 20L 2 /min 2 value (considering Qec = 2 L/min and GF = 10 L/min) was associated with an EC MV ratio between 61% and 29% for 1.8 m 2 oxygenators, and between 62% and 38% for 1.3 m 2 oxygenators.
Conclusion:The decarboxylation index is a simple parameter to predict CO 2 removal and EC MV ratio under extracorporeal respiratory support.
Background
Spontaneous breathing trials are performed in critically ill intubated patients in order to assess readiness to be weaned from mechanical ventilation. In patients with difficult weaning (i.e. not extubated after their first SBT), performing SBT using pressure support with or without positive end-expiratory pressure or using T-piece is debated. As ventilatory support during SBT is greater on pressure support than on T-piece and as positive end-expiratory pressure can prevent weaning-induced pulmonary oedema, we hypothesized that their combination and large use of post-extubation non-invasive ventilation may shorten the time until successful extubation as compared with T-piece, without increasing the rate of reintubation.
Methods
SBT-ICU is a monocentric prospective open labelled, randomized controlled superiority trial comparing two mechanical ventilation weaning strategies; i.e. daily spontaneous breathing trials using pressure support with positive end-expiratory pressure or T-piece. The primary outcome will be time until successful extubation (defined by as extubation, without reintubation or death within the seven following days).
Discussion
This paper describes the protocol of the SBT-ICU trial. Enrolment of patients in the study is ongoing.
Trial registration
ClinicalTrials.gov NCT03861117. Registered on March 1, 2019, before the beginning of inclusion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.