Rationale:

The novel coronavirus disease (COVID-19) pandemic is rapidly expanding across the world, with
over 60.000 new cases each day as of late March 2020. Healthcare workers are struggling to
provide the best care for patients with proven or suspected COVID-19. Approaches for clinical
care vary widely between and within countries and new insights are acquired rapidly. This
includes the way invasive ventilation is applied.

Objective:

To determine and compare invasive ventilation settings and parameters in COVID-19 patients in
the Netherlands, and to determine associations with clinical outcomes.

Hypotheses:

Invasive ventilation settings and parameters vary between intensive care units (ICUs) in
hospitals in the Netherlands; certain ventilator settings have an independent association
with duration of ventilation in COVID-19 patients.

Study design:

Multicenter, national, retrospective, observational study in COVID-19 patients with
respiratory failure, requiring invasive ventilation in intensive care unit (ICU) in hospitals
in the Netherlands.

Study population:

The data of at least 1,000 consecutively invasively ventilated COVID-19 patients admitted to
intensive care units (ICUs) of hospitals in the Netherlands. This study will not be
restricted to the 'formal' ICUs, as patients may also receive invasive ventilation in other
locations within the hospital during the COVID-19 pandemic.

Methods:

In every patient, granular ventilator settings and parameters are collected from start of
invasive ventilation for up to 72 hours. Patients will be followed up until ICU and hospital
discharge, and until day 90.

Sample size calculation:

No formal sample size calculation is needed. We expect to capture at least 1,000 patients,
but will continue collecting data of new patients for at least 8 weeks.

Study endpoints:

Main ventilator settings (including tidal volume, airway pressures, oxygen fraction and
respiratory rate) (primary) and parameters (blood gas results); use of rescue therapies
(including prone positioning); use of sedatives, vasopressors and inotropes; daily cumulative
fluid balances; development of kidney injury; ventilator-free days and alive at day 28
(VFD-28), duration of ICU and hospital stay, and ICU, hospital and 90-day mortality.

Nature and extent of the burden and risks associated with participation, benefit and group
relatedness:

Retrospective collection of data regarding ventilation management and major clinical
endpoints is without risk for the individual patient.