Anestéziológia a intenzívna medicína 1/2017

High flow ventilatory support applied nasally – High flow nasal ventilation (HFloNV)

The aim of traditional oxygenotherapy is to increase the fraction of alveolar oxygen and thus improve the oxygenation of arterial blood. In the recent 20 years there were systems developed that applied breathing gas with certain set FiO2 through sealed nasal canulla while being heated to 35-37 °C and humidified to 100% of relative humidity. This way of application has been mainly used in newborns with ventilation disorders. High Flow Nasal Ventilation (HFloNV) has also been started to be applied in adults through sealed binasal cannula to deliver 37°C heated and 100% humidified gas. Gas flow (40-60 l/min) through cannula generates overpressure in nasopharynx, which subsequently produces dynamic positive endexpiratory pressure (PEEP). That is better tolerated than classic CPAP applied nasally or by facemask. The high potential benefit of this ventilatory support is the ability of HFloNV to continually remove CO2 from nasopharynx and upper airways. HFloNV ventilatory support has been introduced in patients with hypoxic respiratory failure (ARDS 1.level, lung fibrosis, COPD, pneumonia, lung edema, cardiac surgery with respiratory insuficiency, postextubation respiratory insuficiency, morbidly obese patients, do-not-intubate terminal patients). However some papers have already shown that liberal application of HFloNV may lead to its failure and subsequent prolonged intubation and controlled ventilation and possibly to increased 30-day mortality in some patients. The results have shown that HFloNV might be a perspective method of ventilatory support that is able to reliably replace noninvasive mask ventilation in some cases.

Keywords: oxygenoterapy, high flow oxygen, high flow nasal ventilation, respiratory insufficiency