Change in PEEP: Patients will undergo a decremental PEEP trial to determine the crossing-point PEEP. Secondly, three PEEP levels (low collapse PEEP, low overdistention PEEP and crossing point between lung collapse and overdistention PEEP) will be compared in a randomized order with 30-minute steps
Study summary
The management ARDS relies on ventilatory strategies aimed at limiting ventilator-induced lung injury (VILI). The setting of PEEP is still subject of debate, as randomized clinical trials comparing standardized higher versus lower PEEP strategies failed to demonstrate a clear survival advantage. Only few studies explored the hemodynamic effects of various PEEP levels depending on lung recruitability. Furthermore, the role of PEEP-mediated lung collapse and overdistention on patients' hemodynamics has yet to be elucidated. In this physiologic study, the association between EIT-measured lung collapse and overdistention and cardiac function will be explored, accounting for the individual potential for lung recruitment, partitioned respiratory mechanics and cardiac preload responsiveness. Three PEEP levels will be tested in a randomized, crossover fashion: PEEP corresponding to the crossing point between lung collapse and overdistention, PEEP associated with low lung collapse, PEEP associated with low lung overdistention.
Eligibility
Sex
ALL
Min age
18 Years
Max age
—
Healthy volunteers
No
Inclusion Criteria:
* acute respiratory failure with onset \< 1 week from a predisposing risk factor, such as pneumonia, non-pulmonary infection, trauma, transfusion, aspiration, or shock;
* bilateral opacities on chest radiography and computed tomography or bilateral B lines and/or consolidations on lung ultrasound not fully explained by effusions, atelectasis, or nodules/masses;
* pulmonary edema not exclusively or primarily attributable to cardiogenic pulmonary edema/fluid overload, and hypoxemia/gas exchange abnormalities not primarily attributable to atelectasis;
* PaO2/FiO2 ratio ≤ 200 during invasive controlled mechanical ventilation;
Exclusion Criteria:
* age \<18 years;
* pregnancy;
* signs of barotrauma or documented pneumothorax;
* severe tachycardia (HR \> 120 bpm) and severe lacticaemia (lac \> 4 mmol/L)
* pre-existing decompensated heart failure (NYHA class 3-4 and/or documented left ventricular ejection fraction \< 35%);
* contraindications to EIT placing (open chest wounds, presence of cardiac pacemaker);
* intubation as a result of an acute exacerbation of chronic pulmonary disease;
* contraindications to esophageal balloon placement (high bleeding risk, esophageal varices).
Primary outcome measure(s)
Impact of lung collapse on cardiac output — Assesment performed at the end of each of the three 30 minute steps Evaluation of the relative contribution of lung collapse (arbitrary units) on patients' cardiac output at different PEEP levels (L/min)
Impact of lung collapse on pulmonary vascular resistance — Assesment performed at the end of each of the three 30 minute steps Evaluation of the relative contribution of lung collapse (arbitrary units) on pulmonary vascular resistance (dyn·s/cm\^5) at different PEEP levels
Impact of lung overdistention on cardiac output — Assesment performed at the end of each of the three 30 minute steps Evaluation of the relative contribution of lung overdistention (arbitrary units) on patients' cardiac output at different PEEP levels (L/min)
Impact of lung overdistention on pulmonary vascular resistance — Assesment performed at the end of each of the three 30 minute steps Evaluation of the relative contribution of lung overdistention (arbitrary units) on pulmonary vascular resistance (dyn·s/cm\^5) at different PEEP levels
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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