Effectiveness of high flow oxygen therapy in patients with hematologic malignancy acute hypoxemic respiratory failure

Acute respiratory failure (ARF) is the leading reason for ICU admission in immunocompromised patients. Usual oxygen therapy involves administering low-to-medium oxygen flows through a nasal cannula or mask to achieve SpO2≥95%.

High-flow nasal oxygen [HFNO] therapy is a focus of growing attention as an alternative to standard oxygen therapy. By providing warmed and humidified gas, HFNO allows the delivery of higher flow rates [of up to 60 L/min] via nasal cannula devices, with fraction of inspired oxygen (FiO2) values of nearly 100%. Physiological benefits of HFNO consist of higher and constant FiO2 values, decreased work of breathing, nasopharyngeal washout leading to improved breathing-effort efficiency, and higher positive airway pressures associated with better lung recruitment.

Clinical consequences of these physiological benefits include alleviation of dyspnea and discomfort, decreases in tachypnea and signs of respiratory distress, a diminished need for intubation in patients with severe hypoxemia, and decreased mortality in unselected patients with acute hypoxemic respiratory failure However, although preliminary data establish the feasibility and safety of this technique, HFNO has never been properly evaluated in immunocompromised patients.

Thus, this project aims at demonstrating that HFNO is superior to low/medium-flow (standard) oxygen, minimizing the need for endotracheal intubation

Inclusion Criteria:

• Known immunosuppression defined as haematological malignancy.
• Need for oxygen therapy defined as with oxygen free arterial blood gas examination one or more of the following: (a) PaO2/FiO2<300 mmHg (b) PaCO2≤45 mmHg (c) SaO2<92%
• Respiratory distress with a respiratory rate >22/min

Exclusion Criteria:

• Refusal of study participation
• Pregnancy or breastfeeding
• Hypercapnia with a formal indication for non-invasive mechanical ventilation (NIMV) (PaCO2 ≥ 45 mmHg)
• Patients whose clinicians have decided on NIMV (Non-Invasive Mechanical Ventilation) and IMV (Invasive Mechanical Ventilation)
• Haemodynamic instability (mean arterial pressure <65 mmHg)
• Vasopressor needs
• Awareness confusion and disorientation