Historical Development of High-Flow Nasal Oxygen
The term "THRIVE" (Transnasal Humidified Rapid Insufflation Ventilatory Exchange) was coined in 2015 by Patel and Nouraei to describe the application of high-flow (30-70 L/min) warmed humidified oxygen in adult patients with difficult airways 1. This represents the formal naming and clinical characterization of high-flow nasal oxygen as a distinct therapeutic modality, though the technology evolved from earlier apnoeic oxygenation techniques.
Evolution of Nasal Oxygen Delivery
The development of HFNO followed a progression of increasingly sophisticated nasal oxygen delivery methods:
Traditional low-flow nasal oxygen (flow rates <15 L/min) has been used for decades, with simple nasal cannulae delivering oxygen at maximum flow rates of approximately 15 L/min 1.
Intermediate techniques emerged in the 2000s, including nasal oxygenation during intubation (NO DESAT), first described by Levitan in 2010, which used flow rates up to 15 L/min 1.
High-flow humidified nasal oxygen systems capable of delivering flows up to 60 L/min became clinically available and gained widespread adoption in the 2010s 1.
Key Technological Advancement
The critical innovation enabling HFNO was the integration of warming and humidification systems, as cold dry oxygen at high flow rates causes mucosal drying, pain, discomfort, sinus headaches, and bleeding, limiting tolerability 1. The heated humidification component made high flow rates (30-70 L/min) tolerable for patients, distinguishing HFNO from earlier low-flow systems 2, 3.
Clinical Recognition and Evidence Base
The systematic literature search for HFNO evidence began with studies from January 2000 onward, indicating that clinical research on this modality emerged in the early 2000s 1.
By 2015, HFNC systems were described as "gaining popularity" and being used for multiple clinical indications, though high-quality evidence remained limited at that time 2.
The first formal clinical guidelines from major medical societies appeared in 2017 (British Thoracic Society) and 2021 (American College of Physicians), reflecting the maturation of the evidence base 1.