so what is high-flow therapy high-flow therapy is when oxygen is being delivered to the patient at a flow rate that meets or exceeds their in Spiteri flow demand what does that mean well did you know that at rest the average adult will inhale at a speed of 20 to 30 liters per minute in other words if someone was standing next to you right now with a radar gun pointing at your nose capable of measuring how fast you're inhaling while you're relaxed the speed at which you inhale would be at around 20 to 30 liters per minute so high flow therapy should be capable of matching the inspiratory flow or even exceeding it if an oxygen device delivers less than the patient's inspiratory flow then the delivery is called low flow so because the average adult who is at rest inhales at a speed or flow of 20 to 30 liters per minute a high flow device should be capable of delivering at least that much now in order for this high flow of oxygen to be comfortable to the patients the oxygen should be heated and humidified to maximize patient tolerance and comfort and sometimes you'll see high flow therapy described as heated and humidified high flow oxygen therapy or heated and humidified high flow nasal canula or to keep it short it may be referred to as h h fnc or hf n C or even HF ot or hft or some other variation of that more recently vapor therm has chosen to refer to their heated high flow therapy as h hv ni they've even tried to describe h v ni as mask free ni v but don't get thrown off on the FDA's website it clearly identifies their device type as high flow humidified oxygen delivery device now like other high flow devices they deliver a high flow of oxygen and it is heated and humidified to help meet patient comfort intolerance and some devices like vapor therms precision flow go up to 40 liters per minute others like the F and P are vote to go up to 60 liters of flow while still others can go even higher because at the end of the day we're just trying to meet the inspiratory flow of a patient and when that patient is in respiratory distress that inspiratory demand can be as high as a hundred liters per minute yikes so should high flow therapy be a replacement to other forms of therapy like non-invasive ventilation the answer absolutely not high flow oxygen delivers just that a high flow of oxygen but sometimes patients have issues with co2 or ventilation and not just issues with o2 or oxygen ation n IV is effective for both oxygenation and ventilation this is why H of T and n IV are often used together on some patients in a complementary fashion for example some patients may be on high flow therapy but require more support clinicians sometimes escalate to n IV to prevent if possible intubation and invasive mechanical ventilation and if a patient is on n IV and can tolerate short breaks clinicians sometimes switch to high flow therapy to allow the patient to have that temporary break from n IV where they can eat talk with the relatives take an oral medication you get the idea in fact in a vapor therm sponsored study there were a hundred and four patients who presented to the ER in respiratory distress and they were initially placed on high-flow oxygen of those 104 patients unfortunately 27 of them failed and of the 27 four were immediately intubated but the other 23 patients were switched from the high flow oxygen to NIV and of the 23 patients who failed with high flow oxygen and were switched to an IV 20 of them improved and did not need further escalation to intubation in fact in another study patients at high risk of post extubation failure were placed in one of two categories the first category was high flow therapy only and the other group allowed for both an IV and - era P now the patients that one on both n IV and hft had a significantly lower rate of reintubation versus the group that went on hf t only so don't get confused hft is definitely not mask free n IV but it is a great tool to treat patients with oxygenation issues who are in respiratory distress so just a quick final summary on high-flow there High Flow oxygen therapy usually delivers oxygen at a flow rate equal to or higher than the patient's actual inspiratory flow rate it should be heated and humidified for patient tolerance and depending on the flow rate and the seal around the nose and mouth - may create a CPAP effect although we don't know exactly how much it also may wash out some co2 that is in the upper airway which is often referred to as co2 dead space washout but again we don't know exactly how much so that's your quick introduction to high flow therapy