Mechanical power and ventilatory efficiency during flow-controlled ventilation in severe COVID-19 ARDS
Here the presentation of Dr. Alberto Grassetto at ESAIC 2022.
Background
The prevention of
ventilator-induced lung injury (VILI) is the mainstay of the management of
mechanical ventilation in patients with ARDS. Mechanical power, which
represents the total inflation energy transferred from the mechanical
ventilator to the lungs, including flow and respiratory rate, is associated
with VILI and mortality in patients with ARDS.
Flow
controlled Ventilation (FCV)
FCV
is a ventilation mode that provides low, constant flow throughout both
inspiration and expiration without pauses implemented by the Evone® ventilator
(Ventinova Medical, Eindhoven, The Netherlands). By avoiding high peak flows
and reduced respiratory rate, FCV may lead to the minimization of applied and
dissipated energy in order to attenuate VILI in ARDS patients.
Goal
To evaluate
the ventilatory efficiency
and applied mechanical power during FCV in ARDS patients.
Methods
Design:
Prospective observational study
Inclusion criteria:
•Patients (n=10) with COVID-19 related
ARDS
•Conventional
volume-controlled mechanical ventilation (CMV)
•Prone
positioning > 12 hours
•Receiving
neuromuscular blockade
•P/F
ratio <150 mmHg
We
registered the changes in ventilatory settings, respiratory mechanics and gas
exchanges during the transition from CMV to FCV and back.
Results
As
compared to CMV, FCV resulted in:
•Lower
inspiratory flow, with a decreased respiratory rate and minute ventilation.
•Lower
applied mechanical power, despite similar driving pressure and compliance
•Lower
ventilatory ratio.
Conclusions
Our findings suggest that FCV may
reduce mechanical power and increase ventilatory efficiency in patients who
remain severely hypoxemic despite the optimization of CMV.
