Clinical trial NCT04818164: Prone Position Improves End-Expiratory Lung Volumes in COVID-19 Acute Respiratory Distress Syndrome
Official title: Prone Position Improves End-Expiratory Lung Volumes in COVID-19 Associated Acute Respiratory Distress Syndrome: An Observational Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Acute Respiratory Distress Syndrome
Coronavirus
Mechanical Ventilation Complication
Ventilation Perfusion Mismatch
Keywords: acute respiratory distress syndrome
prone position
lung recruitment
Lead sponsor: Istanbul University - Cerrahpasa
Sponsor class: OTHER
First posted: 2021-03-26
Enrollment: 43
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Adult Patients receiving invasive mechanic ventilation due to Covid-19 ARDS

Brief summary: Covid-19 associated Acute Respiratory Distress Syndrome (ARDS) may present with profound hypoxemia not fully explained with pulmonary infiltrates. Accordingly, how prone positioning improves oxygenation in these patients is not fully known. The investigators conducted a study among patients with severe Covid-19 ARDS receiving prone position for at least 16 hours. End Expiratory Lung Volume (EELV) was measured with Nitrogen wash-in/wash-out technique before (Supine Position 1- SP1), during (Prone Position - PP) and after (Supine Position 2 - SP2) prone positioning.

Detailed description: After initiation of invasive mechanical ventilation, initial ventilator settings were performed by the attending physician. These settings include titration of best PEEP to promote oxygenation if Spo2 \<92% despite a Fio2 higher than 80% or best compliance that do not jeopardize oxygenation if Fio2 is between 50-80% and Spo2 \>92%. After a period of 30 minutes for stabilisation, the first set of measurements were done in the SP1 position. Afterwards, the patient was turned to prone position with the same PEEP (which was unchanged throughout the study period) and measurements were repeated every four hours until the patient was reverted back to SP2. Eventually, there were 7 measurements in total. (SP1, PP0, PP4, PP8, PP12, PP16, SP2). Dead space ventilation and shunt fraction calculations were made based on central venous blood gas measurements and oxygen consumption and carbon dioxide production at the relevant timepoint.

Eligibility criteria: Inclusion Criteria:

* Patients were considered eligible if they met the Berlin definition criteria for ARDS and intubated due to increased work of breathing and/or worsening hypoxemia. All patients had a positive Covid-19 real time Polymerase Chain Reaction test

Exclusion Criteria:

* Exclusion criteria were; age \< 18 years, ARDS resulting from other risk factors, presence of chest drainage tubes, tracheostomy, pneumomediastinum, hemodynamic instability (systolic blood pressure \< 100 mmHg, lactate \> 2 mmol/l, or an increase in lactate concentrations for 20% in two consecutive blood gas analysis within 2 hours interval) and suspicion or confirmed pulmonary emboli.

Primary outcomes:
measure: Partial Pressure of Oxygen/ Fraction of Inspired Oxygen
timeFrame: 1 day
measure: End Expiratory Lung Volume
timeFrame: 1 day
Secondary outcomes:
measure: Lung Compliance
timeFrame: 1 day
measure: Dead Space Ventilation
timeFrame: 1 day
Other outcomes:
Locations:
city: Istanbul
country: Turkey
facility: Istanbul University-Cerrahpaşa
Study officials:
affiliation: Istanbul University - Cerrahpasa
name: Olcay Dilken, Dr.
role: PRINCIPAL_INVESTIGATOR
References: