IntHyx : Intubation Strategies for Patients With Acute Hypoxemic Respiratory Failure

Overview

Acute hypoxemic respiratory failure requires endotracheal intubation and invasive mechanical ventilation in approximately 30-40% of cases, due to severe hypoxemia and/or clinical signs of acute respiratory distress. The primary objectives of invasive mechanical ventilation are to reduce respiratory effort and improve oxygenation. However, this intervention is also associated with both direct and indirect adverse effects, mainly linked to the need for sedation and often neuromuscular blockade. These include hemodynamic compromise, neuromuscular weakness, ventilator-induced lung injury, and infectious complications. An ideal intubation strategy would therefore strike a balance: avoiding the risks of delayed intubation-such as refractory hypoxemia, excessive respiratory effort, and patient self-inflicted lung injury (P-SILI)-while limiting complications associated with invasive mechanical ventilation by withholding it in patients who might otherwise recover without. To date, the optimal strategy for achieving this risk-benefit balance remains uncertain. Clinical practice suggests a broad consensus on the necessity of intubation when so-called safety criteria are met: severe hypoxemia (SaO₂/FiO₂ ratio \< 88), marked respiratory distress (use of accessory muscles, thoracoabdominal paradox, respiratory rate \> 40/min), extra-respiratory manifestations of hypoxia (e.g., altered consciousness), and/or uncontrolled hemodynamic instability. Beyond these safety thresholds, however, debate persists. Some advocate for earlier intubation-a so-called liberal approach-triggered by predefined hypoxemia criteria (e.g., SpO₂/FiO₂ \< 110), with the aim of limiting the deleterious consequences of sustained hypoxemia. In routine practice, the criteria guiding intubation vary widely between clinicians and cannot be attributed to strong scientific evidence. This study therefore seeks to compare, in a randomized interventional design, the two main strategies currently applied across centers: * Liberal intubation strategy: prioritizing the prevention of organ dysfunction related to hypoxemia (notably hypoxic cardiac arrest) and the risk of P-SILI. * Restrictive intubation strategy: prioritizing the reduction of invasive mechanical ventilation use, with the goal of minimizing ventilation-related harm and its associated therapeutic burden.

Interventions

• Procedure Restrictive intubation strategy
  Endotracheal intubation is recommended only if at least one of the following criteria persists for more than 5 minutes: 1. Respiratory rate \> 40/min, persistent use of accessory muscles, or thoracoabdominal paradox. 2. SpO₂/FiO₂ \< 88. 3. Neurological or systemic impairment attributable to hypoxemia, defined as: altered higher brain functions without another identifiable cause, Glasgow Coma Scale ≤ 12, uncontrolled hemodynamic instability, or rising lactate levels.
• Procedure Liberal intubation strategy
  Endotracheal intubation is recommended if SpO₂/FiO₂ \< 110 for more than 5 minutes. In addition, intubation is also recommended in the liberal strategy if any of the restrictive strategy criteria occur and persist for more than 5 minutes.

Primary outcome measures

• Impact of a liberal intubation strategy compared to a restrictive strategy in regards to organ support duration, taking mortality into account [Time frame: Day 28]

Secondary outcome measures (8)

• Evaluate the impact of the intubation strategy on intubation rates over time. [Time frame: Day 28]
• Assess the impact of the intubation strategy on each component of the composite primary endpoint. [Time frame: Day 28]
• Assess the impact of the intubation strategy on the severity of vital organ failure and the duration of care. [Time frame: Day 28]
• Assess the impact of the intubation strategy on quality of life at day 90. [Time frame: Day 90]
• Assess the impact of the intubation strategy on the rate of procedure-related adverse events. [Time frame: within 30 minutes of the start of the intubation procedure]
• Assess the impact of the intubation strategy on the rate of adverse events related to invasive mechanical ventilation. [Time frame: Day 28]
• Assess the impact of the intubation strategy on the rate of adverse events potentially related to delayed intubation. [Time frame: Day 28]
• Estimated tidal volume by Electrical impedance tomography (EIT) [Time frame: 1 hour, 24 hours, and 48 hours after enrollment]

Eligibility criteria

Inclusion criteria

• Adult patient
• Patient admitted to intensive care less than 24 hours ago
• Acute respiratory failure with hypoxemia defined by either:

• Oxygen therapy ≥ 10 L/min via high-concentration mask required for 92 ≤ SpO2 ≤ 98%
• High-flow oxygen therapy with FiO2 ≥ 50% required for 92 ≤ SpO2 ≤ 98%
• Informed consent of the patient or a trusted relative (when the patient is unable to give consent)

Exclusion criteria

• Acute hypercapnic respiratory failure (defined by PaCO2 > 45 mmHg)
• Cardiogenic pulmonary edema
• Exacerbation of chronic respiratory disease
• Respiratory failure requiring long-term oxygen therapy
• Neuromuscular disease
• Glasgow Coma Scale score ≤ 12
• Decision to intubate immediately
• Invasive mechanical ventilation within the previous 7 days
• Treatment limitation decisions for intubation
• Person deprived of liberty by judicial or administrative decision : Person undergoing compulsory psychiatric care, person subject to legal protection measures, Pregnant, breastfeeding, or parturient patient

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

France · 9 centers

• Angers University Hospital, ICU — Angers
• Le Mans Hospital, ICU — Le Mans
• Nantes University Hospital, ICU — Nantes
• Orléans University hospital, ICU — Orléans
• Pitié-Salpétrière Hospital, Paris University Hospital, ICU — Paris
• Guadeloupe University Hospital, ICU — Pointe à Pitre
• Rennes University Hospital, ICU — Rennes
• Tours University Hospital, ICU — Tours
• … and 1 more center

Identifiers

NCT: NCT07189078 · 49RC24_0293 · 2025-A01380-49

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗