Assessment of PaO2/FiO2 Ratio Pre and POst INTubation (APPOINT)

Assessment of PaO2/FiO2 Ratio Pre and POst INTubation (The APPOINT Study)

We designed this study to dtermine whether invasive mechanical ventilation (MV) would have an impact on the reclassification of patients with acute hypoxemic respiratory failure (AHRF) -treated previously with non-invasive respiratory support- into categories of severity (mild, moderate, and severe). Our hypothesis is that the assessment of PaO2/FiO2 ratio on PEEP greater or equal to 5 cmH2O after intubation, in patients labeled as mild/moderate/severe AHRF while on non-invasive respiratory support, would identify that a marked proportion of patients would change the degree of severity after a brief period of invasive MV

Study Overview

• Status: Active, not recruiting
• Conditions: Acute Hypoxemic Respiratory Failure
• Intervention / Treatment: Device: Mechanical ventilation

Detailed Description

Current criteria for definition of the acute respiratory distress syndrome (AHRF) are inadequate for inclusion of patients into clinical trials due to: (i) the lack of standardization for measuring the oxygenation defect (as assessed by the PaO2/FiO2 ratio) and (ii) the inclusion of non-intubated patients into the mild category of severity. We questioned whether the PaO2/FiO2 (P/F) ratio calculated before endotracheal intubation in non-intubated patients who otherwise meet AHRF criteria, would still meet the severity threshold once patients are intubated.

We will examine at 24 after intubation and initiation of MV whether adult patients with AHRF remained in the same AHRF category of severity (mild, moderate, severe) or do not meet the PaO2/FiO2 criterion for AHRF. If our hypothesis is supported, it would suggest that stratification of patients labeled based on P/F ratio while treated with non-invasive respiratory support is of limited utility for testing specific therapies for AHRF in non-intubated patients.

This is a high quality screening, longitudinal, defined population, retrospective study.

• Study Type: Observational
• Enrollment (Estimated): 400

Contacts and Locations

Study Locations

• Spain
  • Las Palmas
    • Las Palmas de Gran Canaria, Las Palmas, Spain, 35003
      • Jesús Villar
• United States
  • Illinois
    • Chicago, Illinois, United States, 60612
      • Rush University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with AHRF (defined as PaO2/FiO2 lower or equal to 300 mmHg and FiO2 greater or equal to 0.3, on non-invasive ventilatory support) prior to intubation.

Description

Inclusion Criteria:

• Patients meeting criteria for AHRF while they are on non-invasive respiratory support.
• We will only include patients who had arterial blood gases (ABG) within a time-frame of the last 5 hours of NIV and the first 5 hours of invasive MV.
• We will only include patients treated with high-flow oxygen nasal cannula (HFNC), or continuous positive airway pressure (CPAP), or bilevel positive pressure (BiPAP).

Exclusion Criteria:

• Patients who never required HFNC, or CPAP, or BiPAP before intubation.
• Patients with no ABG during the last 5 hours of NIV before intubation.
• Patients with no ABG during the first 5 hours after initiation of invasive MV.
• Patients treated with inhaled pulmonary vasodilator only before or only after intubation.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients on non-invasive ventilatory support to IMV; Patients with AHRF treated with non-invasive ventilatory support [for the purpose of this study we included High-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and non-invasive ventilation (NIV)] who required endotracheal intubation and invasive mechical ventilation.	Device: Mechanical ventilation; Need for endotracheal intubation and invasive mechanical ventilation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the degree of lung severity	from severe/moderate to moderate/mild, from moderate/mild to mild after a brief period of invasive MV	60 days

Collaborators and Investigators

• Sponsor: Dr. Negrin University Hospital
• Collaborators: Rush University Medical Center
• Investigators: Study Chair: Jesús Villar, Hospital Universitario D. Negrin

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2023
• Primary Completion (Estimated): November 30, 2025
• Study Completion (Estimated): November 30, 2025

Study Registration Dates

• First Submitted: May 2, 2023
• First Submitted That Met QC Criteria: May 2, 2023
• First Posted (Actual): May 10, 2023

Study Record Updates

• Last Update Posted (Estimated): August 26, 2025
• Last Update Submitted That Met QC Criteria: August 20, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: mechanical ventilation; acute respiratory failure; non-invasive ventilatory support
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency; Therapeutics; Airway Management; Resuscitation; Emergency Treatment; Respiratory Therapy; Respiration, Artificial
• Other Study ID Numbers: 2022-161-1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No