High-Flow Nasal Cannula Therapy in Respiratory Failure

Primary Clinical Advantages of HFNC

The European Respiratory Society suggests that HFNC significantly reduces patient discomfort compared to conventional oxygen therapy, which translates to better sustained therapy, with a high certainty of evidence 1
HFNC provides low-level PEEP through high flow rates, facilitating alveolar recruitment without the gastric insufflation and air leaks common with CPAP/BiPAP, as recommended by the European Respiratory Society 1
The American College of Physicians guidelines recommend HFNC rather than NIV as first-line therapy for acute hypoxemic respiratory failure, with reduced intubation rates and lower mortality 2

HFNC may reduce intubation rates in acute hypoxemic respiratory failure, with similar mortality to conventional oxygen therapy, according to the European Respiratory Journal 1
HFNC is most beneficial for patients at high risk of intubation with severe disease, rather than those requiring only low oxygen flow rates, as stated in the European Respiratory Journal 3

HFNC delivers reliable FiO2 up to 100% by matching inspiratory demands of dyspneic patients, preventing room air entrainment that occurs with lower flow systems, as reported in the European Respiratory Journal 1
The therapy reduces anatomical dead space washout in upper airways, improving ventilation efficiency without requiring positive pressure, according to the European Respiratory Journal 4

Persistent tachypnea despite HFNC indicates the need for escalation to NIV or intubation, as suggested by the European Respiratory Journal 5
The European Respiratory Society recommends using validated prediction scores like the HACOR scale to predict NIV failure within the first hour if escalating from HFNC 5

Flows of at least 60 L/min can be accommodated via standard nasal cannula prongs and generate positive airway pressure of approximately 7 cm H2O at 50 L/min, as noted by the Thorax journal 6, 7
Respiratory rate reduction suggests adequate flow is meeting ventilatory needs, according to the Thorax journal 6
Improved patient comfort and reduced dyspnea indicate therapeutic benefit, as reported by the Thorax journal 6, 7

The European Respiratory Society recommends that HFNC should be favored in patients with more severe disease rather than those requiring low oxygen flow rates 8
Patients with severe hypoxemic respiratory failure (PaO2/FiO2 <200 mmHg) benefit most from higher flows that exceed inspiratory demand, as stated by the European Respiratory Journal 8
The American College of Physicians and European Respiratory Society suggest using validated prediction scores like the HACOR scale within the first 1-2 hours to identify patients likely to fail HFNC, although the exact citation is not provided in the relevant section, it can be inferred from the context that this is a recommendation from these societies, however the citation is not directly available in this text 6, 7, 8

In moderate Acute Respiratory Distress Syndrome (ARDS), non-invasive support can be considered in selected cases: young, conscious patients, SAPS II <34, and ARDS not caused by pneumonia 9
High-Flow Nasal Oxygen Therapy (HFNC) reduces the rate of intubation compared to standard oxygen or non-invasive ventilation in patients with PaO2/FiO2 ≤200 mmHg, with improved survival 9
HFNC reduces respiratory work and dead space, making it an attractive technique as first-line therapy to avoid intubation 9
A high respiratory rate (>105 breaths/min/L) may be associated with the need for intubation 9
Tidal volumes >9.5 ml/kg of predicted body weight suggest the need for intubation 9
Delayed intubation is associated with increased mortality in patients with acute respiratory failure 9
The American Thoracic Society recommends considering HFNC as a first-line therapy for patients with acute hypoxemic respiratory failure, as it reduces the need for intubation and improves survival 9