HFNC and Acute Hypercapnic Respiratory Failure

High Flow Nasal Oxygen Therapy in Chronic Obstructive Pulmonary Disease (COPD) Patients With Acute Hypercapnic Respiratory Failure (AHRF)

High-flow nasal cannula (HFNC) enables delivering humidified gas at high-flow rates controlling the oxygen inspired fraction (FiO2). Its efficacy has been demonstrated in hypoxemic acute respiratory failure. However, little is known about its use in hypercapnic acute respiratory failure (ARF). Therefore, we aimed to evaluate the effect of using HFNC through "Precision Flow" equipment as first line of ventilatory support for COPD patients with hypercapnic acute respiratory failure.

Inclusion Criteria:

• Moderate to very severe COPD patients (GOLD 2 to 4) over 18 years old admitted to the ICU with hypercapnic ARF (PaCO2> 45 mmHg and respiratory acidosis [pH ≥7.30], with or without hypoxemia + one of the following: Respiratory Rate ≥25 cycles per minute, intercostal and / or supraclavicular recruitment, or thoraco-abdominal synchrony, no prior use of NIV)

Exclusion Criteria:

• Patients less than 18 years old
• Mild COPD patients
• Absence of hypercapnia
• Kelly M Score > 3
• Haemodynamic instability (despite fluid resuscitation)
• NIV or Invasive Mechanical Ventilation (IMV) (Need to use previously to HFNC)
• Contraindications to implement high-flow oxygen therapy.