High-flow Nasal Cannula Versus Conventional Oxygen During Awake Tracheal Intubation With Difficult Airways

Официальное название

High-Flow Nasal Cannula Versus Conventional Oxygen to Prevent Hypoxaemia During Awake Tracheal Intubation: A Multicentre, Open-Label, Randomised Controlled Trial (OXYOPTI-ATI)

Обзор

Study Background Airway management is one of the most fundamental and critical technical procedures in anesthesiology, critical care, and emergency medicine. Difficult airway management remains a major challenge in these fields, particularly when a "cannot intubate, cannot ventilate" scenario occurs during the induction of general anesthesia. Such events can rapidly lead to hypoxemia, resulting in brain injury or even death, and have become a significant source of anesthesia-related severe complications and medical disputes. Awake tracheal intubation (ATI) is considered the gold standard for airway management in patients with anticipated difficult airways, as it preserves spontaneous breathing and thereby reduces the risk of catastrophic airway failure during anesthesia induction. However, despite routine supplemental oxygen administration, hypoxemia remains one of the most common and potentially serious complications during ATI. When low-flow oxygen therapy (\<30 L/min) is used, the reported incidence of hypoxemia (SpO₂ ≤ 90%) ranges from 12% to 29%. Once hypoxemia occurs during ATI, it may not only interrupt the procedure, increase the number of intubation attempts, and reduce the likelihood of successful intubation, but also trigger serious cardiovascular events, thereby compromising patient safety. High-flow nasal cannula (HFNC) oxygen therapy can deliver heated and humidified gas at flow rates of up to 70 L/min and improve oxygenation and ventilation through mechanisms such as anatomical dead space washout, reduction of work of breathing, and generation of continuous positive airway pressure. HFNC has been shown to improve oxygenation in a variety of medical and procedural settings. However, evidence regarding the role of HFNC during awake tracheal intubation remains controversial and of low quality. There is an urgent need for well-designed multicenter randomized controlled trials specifically focused on the ATI setting, using hypoxemic events as the primary outcome and applying strictly standardized procedures, to provide high-quality evidence on the effectiveness and safety of HFNC during ATI. Such evidence is essential to inform clinical practice and support future updates of airway management guidelines. Study Hypothesis This study hypothesizes that, in patients with anticipated difficult airways undergoing ATI, HFNC is more effective in preventing intubation-related hypoxemic events than conventional low-flow nasal cannula oxygen therapy. Study Objectives Primary Objective: To evaluate the effectiveness of high-flow nasal cannula oxygen therapy compared with conventional low-flow nasal cannula oxygen therapy in preventing hypoxemia during ATI in patients with anticipated difficult airways. Secondary Objectives: To assess the effects of high-flow nasal cannula oxygen therapy versus conventional low-flow nasal cannula oxygen therapy on procedural outcomes of awake tracheal intubation, including the rate of interventions required after hypoxemia, first-attempt intubation success rate, number of intubation attempts, overall ATI success rate, intubation time, and the incidence of adverse events. Study Methods This study is a multicenter, randomized controlled clinical trial. Adult patients undergoing ATI will be recruited from six tertiary hospitals in China. Participants will be randomly assigned to receive either high-flow nasal cannula oxygen therapy or conventional low-flow nasal cannula oxygen therapy throughout the intubation procedure. The study will compare the incidence of hypoxemia between the two groups and further evaluate intubation success rates, intubation time, the need for rescue interventions following hypoxemia, and the incidence of adverse events.

Вмешательства

• Устройство High-Flow Nasal Cannula
  A heated and humidified high-flow nasal oxygen therapy device（Fisher \& Paykel，East Tamaki，New Zealand） set at a flow rate of 40 L/min, an inspired oxygen fraction (FiO₂) of 100%, and a temperature of 37 °C.
• Устройство Ligh-Flow Nasal Cannula
  Low-flow oxygen delivered via a disposable nasal cannula at a flow rate of 4 L/min.

Первичные конечные точки

• Incidence of hypoxemia（SpO₂≤ 90%） [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]

Вторичные конечные точки (10)

• Incidence of SpO₂ ≤ 80% [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• Lowest SpO₂ [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• Cumulative duration of hypoxemia [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• Number of hypoxemic episodes per participant (defined as the first occurrence of SpO₂ ≤ 90% after preoxygenation counted as one episode; subsequent episodes counted if SpO₂ returns to normal and then decreases again) [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• SpO₂ at the time of successful intubation [Срок оценки: At the time of successful intubation up to 24 hours]
• End-tidal carbon dioxide (EtCO₂) at the time of successful intubation [Срок оценки: At the time of successful intubation up to 24 hours]
• Proportion of participants requiring rescue interventions after the occurrence of hypoxemia [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• First-attempt intubation success rate [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• Awake tracheal intubation success rate [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]
• Intubation time [Срок оценки: From initiation of awake tracheal intubation to completion of successful tracheal intubation confirmed by end-tidal carbon dioxide (EtCO₂), assessed up to 30 minutes.]

Критерии участия

Критерии включения

• Presence of an anticipated difficult airway;
• Planned awake tracheal intubation;
• Age ≥ 18 years;
• Willingness to participate in the study and provision of written informed consent.

Критерии исключения

• Contraindications to HFNC use, such as severe nasal obstruction or deformity, recent (within 3 months) nasal or skull base surgery, skull base fracture, or active epistaxis;
• Hemodynamic instability, defined as a mean arterial pressure (MAP) < 65 mmHg or the need for vasoactive medications to maintain blood pressure;
• Pregnancy;
• Current participation in another interventional clinical trial.

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Нет

Дизайн исследования

Распределение

Рандомизированное

Модель

Параллельные группы

Маскирование

Открытое

Основная цель

Поддерживающая терапия

Центры проведения

Китай · 6 центров

• Wuwei People's Hospital — Wuwei
• South China Hospital of Shenzhen University — Шэньчжэнь
• Baoding No.1 Central Hospital — Baoding
• Pizhou Hospital of Traditional Chinese Medicine — Pizhou
• Eye & ENT Hospital of Fudan University — Шанхай
• The First People's Hospital of Neijiang — Neijiang

Публикации

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• Mangan CE, Borow L, Burtnett-Rubin MM, Egan V, Giuntoli RL, Mikuta JJ. Pregnancy outcome in 98 women exposed to diethylstilbestrol in utero, their mothers, and unexposed siblings. Obstet Gynecol. 1982 Mar;59(3):315-9. PMID 7078877
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Идентификаторы

NCT: NCT07384494 · EENTFudan 2025155-1

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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