Anatolian Journal of Emergency Medicine

Yazarlar: Özge Ecmel ONUR, Arzu DENİZBAŞI, Çiğdem ÖZPOLAT

Konular:Tıp

Anahtar Kelimeler:Humidified High-Flow Nasal OxygTherapy,Emergency Medicine,Hypoxemic Respiratory Failure

Özet: Dyspnea is a common complaint of patients visiting the emergency department. Supplemental oxygen therapy plays an important role in the Emergency Department (ED). Drawbacks of conventional oxygen therapy are present. HFNC(humidified high-flow nasal oxygen) is nowadays widely studied in the patients with hypoxemic respiratory failure. HFNC allows for high concentrations (up to 100% FiO2) and flow rates (up to 60 L/min) of oxygen to be delivered at physiological temperatures (37 ◦C) and humidity levels (44 mg H2O/L) through a wide-bore nasal cannula. An HFNC has several benefits compared with those of conventional oxygen therapy, as it provides high flow, humidified oxygen, constant FiO2, and positive airway pressure and reduces dead space. Studies have shown better oxygenation in patients who use an HFNC; however, the changes in PaCO2 differed among studies. HFNC generates a positive airway pressure (between 2 and 8 cmH2O at the pharyngeal level) which resembles positive end-expiratory pressure (PEEP). HFNC results in a significant, flow-dependent ‘CO2 wash out effect’ of the nasopharyngeal space which decreases the anatomical dead space ventilation and therefore the CO2 rebreathing. It is used in emergency services especially in hypoxemic respiratory failure and also in hypercapnic respiratory failure, preintubation oxygenation, acute heart failure. But there are limited data especially in terms of prospective randomised trials. Here we want to review the studies in these clinical situtaions about HFNC.

---