Nasal high flow oxygen (Optiflow™) is a new alternative as it provides warmed humidified oxygen at high flow, and also has been shown to assist breathing and improve recovery. It is comfortable during use and indeed may be more comfortable than standard (dry) oxygen via a facemask (Hudson type) or nasal prongs.
Full Answer
What does high flow oxygen mean?
High-flow oxygen(HFO) consists of a heated, humidified, high-flow nasal cannulathat can deliverup to 100% heated and humidified oxygenat a maximum flowof 60 LPM via nasal prongs or cannula. How many liters of oxygen can go through nasal cannula?
What is considered high-flow O2?
Anything over 12 is considered High Flow O2. Supposedly we should hook the BVM up to 25lpm of O2, but I find that to be wasteful, and 15lpm keeps the reservoir pretty full. Like I said, this is what I was taught.
Is Venti mask high flow?
Venturi masks are considered high-flow oxygen therapy devices. Use this venturi mask oxygen flow rates chart and find the status of oxygen delivered against flow rate. Venturi mask oxygen flow rates chart above shows the usual flow rate of oxygen and fio2 using the venturi mask from 4 L/min to 10 L/min and 24 % to 50%.
When to use high flow nasal cannula?
The use of heated and humidified high flow nasal cannula (HFNC) has become increasingly popular in the treatment of patients with acute respiratory failure through all age groups. I first started using it as a pediatric intensive care fellow, but had little knowledge of how it actually worked.
What is the purpose of high flow oxygen?
High flow oxygen therapy is a breathing support. Continuous, warmed (to 37 degrees) and humidified oxygen is given through a tube placed in the nostrils. Only offered if traditional oxygen therapy isn't helping, high flow oxygen therapy helps reduce the effort your body needs to put into breathing.
What is the difference between high flow oxygen and regular nasal cannula?
When high-flow nasal cannula, or HFNC, is used to deliver oxygen, the flow rates are much higher than can be achieved with traditional nasal cannula. This results in a greater delivery of prescribed oxygen into the lungs, and less entrainment of room air.
What is classed as high flow nasal oxygen?
High-flow nasal cannula (HFNC) therapy is an oxygen supply system capable of delivering up to 100% humidified and heated oxygen at a flow rate of up to 60 liters per minute.
Why is high flow nasal oxygen used?
High-flow nasal oxygen therapy (HFNOT) provides a valuable triad of humidity, high FIO2, and improved patient compliance. It reduces heat and moisture loss from the airway, reduces anatomical dead space, provides PEEP, and improves oxygenation.
Can a patient go home on high flow oxygen?
High flow therapy can be configured to be delivered with or without additional oxygen, depending on the needs of the patient. Oxygen can be added at flow rates of up to 15 L/min. Can high-flow be delivered at home? Yes.
What is the maximum oxygen flow rate for a nasal cannula?
Conventional low-flow devices (e.g., nasal cannula or simple face mask) provide 100% FiO2 at a maximum of 15 liters per minute. Even during quiet breathing, inspiratory flow rates are approximately 30 liters per minute, which exceeds supplemental oxygen flow (3).
What is the difference between low-flow and high flow oxygen?
Low-flow systems often are more comfortable, but the ability to deliver a precise oxygen concentration in various respiratory breathing patterns is limited. A high-flow system can deliver very accurate oxygen concentrations, but is often uncomfortable and obtrusive.
Is 3 liters of oxygen high?
Rates of 4 liters/minute or greater are considered higher oxygen flow.
When should I wean my high-flow nasal cannula?
When the HFNC weaning-off targets are reached (20 L/min and 0.3 for flow and FiO2, respectively), the patient will be transferred to conventional oxygen therapy (mainly low-flow nasal prongs). The primary outcome is the time to successful weaning from HFNC for 24 h.
What is the difference between high flow oxygen and CPAP?
HFNC delivers a heated, humidified airflow, and the FiO2FiO2Definition/Introduction. The fraction of inspired oxygen (FiO2) is the concentration of oxygen in the gas mixture. The gas mixture at room air has a fraction of inspired oxygen of 21%, meaning that the concentration of oxygen at room air is 21%.https://www.ncbi.nlm.nih.gov › books › NBK560867Fraction of Inspired Oxygen - StatPearls - NCBI Bookshelf can be varied between 21% and 100% [8]. HFNC, like CPAP, is a high flow system and is able to generate a positive end expiratory pressure, but unlike CPAP it does not have a valve [9].
What is normal oxygen flow rate?
The normal flow rate of oxygen is usually six to 10 litres per minute and provides a concentration of oxygen between 40-60%. This is why they are often referred to as MC (medium concentration) masks, as 40%-60% is considered to be a medium concentration of oxygen.
Is 4 liters oxygen a lot?
Rates of 4 liters/minute or greater are considered higher oxygen flow. As more scarring develops in the lungs, they become less efficient in delivering the necessary oxygen the body needs.
What's the difference between high flow and low flow oxygen?
Low-flow systems often are more comfortable, but the ability to deliver a precise oxygen concentration in various respiratory breathing patterns is limited. A high-flow system can deliver very accurate oxygen concentrations, but is often uncomfortable and obtrusive.
What are the disadvantages of using a nasal cannula?
Several drawbacks are associated with these devices, which may limit efficacy and tolerance of oxygen delivery. Usually, oxygen is not humidified at low flow, and complaints, especially dry nose, dry throat, and nasal pain, are common.
How does a high flow nasal cannula work?
HFNC systems have been postulated to improve oxygenation and decrease work of breathing by creating a reservoir of oxygen within the nasopharynx and by washing out nasopharyngeal dead space. This effect is similar to what is observed with tracheal gas insufflation.
What are some of the drawbacks about administering oxygen through a nasal cannula?
Limitations: Easily dislodged, not as effective is a patient is a mouth breather or has blocked nostrils or a deviated septum or polyps. A mask fits over the mouth and nose of the patient and consists of exhalation ports (holes on the side of the mask) through which the patient exhales CO2 (carbon dioxide).
Introduction
I wanted to talk to you a little bit today about high flow nasal oxygen. There are a lot of terms that are tossed around. From my perspective, when working with students, I know there can be some confusion as some terms mean the same thing.
What is High Flow Oxygen?
High flow oxygen systems include those that can supply a flow that meets or exceed the patient’s peak inspiratory flow.
High Flow Nasal Cannula (HFNC) Review
High flow nasal cannulas offer flow rates up to 60 lpm with precise FiO2 concentrations up to 100%.
Types of HFNC
Let's now look at the different types of high-flow nasal cannulas. I am just going to talk about a few. I do not claim to be inclusive of all devices that are on the market. I spoke with a few therapists that I know, and these are the main ones that everyone seems to be currently using.
How to administer oxygen to hypoxemic patients?
Administration of supplemental oxygen has been the first-line therapy for hypoxemic patients. Oxygen is generally provided via face masks and nasal cannula. Several drawbacks are associated with these devices, which may limit efficacy and tolerance of oxygen delivery. Usually, oxygen is not humidified at low flow, and complaints, especially dry nose, dry throat, and nasal pain, are common. Bubble humidifiers are commonly used for humidifying air delivered to spontaneously breathing patients, but when absolute humidity is low, patients still complain of discomfort [2,3]. Insufficient heating and humidification leads to poor tolerance to oxygen therapy. Using conventional devices, oxygen flow is limited to no more than 15 L/min. Meanwhile, the inspiratory flow of patients with respiratory failure varies widely in a range from 30 to more than 100 L/min. The difference between patient inspiratory flow and delivered flow is large, and as a result, FIO2is both inconstant and often lower than expected. As an alternative to conventional oxygen delivery for hypoxemic patients, HFNC oxygen therapy has been receiving more and more attention.
What is HFNC in medical?
High-flow nasal cannula (HFNC) oxygen therapy comprises an air/oxygen blender, an active humidifier, a single heated circuit, and a nasal cannula. It delivers adequately heated and humidified medical gas at up to 60 L/min of flow and is considered to have a number of physiological effects: reduction of anatomical dead space, PEEP effect, ...
What is respiratory support?
The purpose of respiratory support is to maintain adequate ventilation and oxygenation. In this, ensuring adequate alveolar ventilation is essential for expelling carbon dioxide produced in the human body. Currently, to ensure adequate alveolar ventilation, minute ventilation is manipulated during invasive or noninvasive ventilatory support. For patients with acute exacerbation of chronic obstructive lung disease (COPD), noninvasive ventilation (NIV) has become the preferred primary modality for respiratory support because it enhances inspiratory tidal volume (VT) and maintains adequate alveolar ventilation [1]. Because of poor mask tolerance, however, NIV is sometimes inapplicable. High-flow nasal cannula (HFNC) oxygen delivery has been gaining attention as an alternative means of respiratory support for critically ill patients. The apparatus comprises an air/oxygen blender, an active heated humidifier, a single heated circuit, and a nasal cannula. At the air/oxygen blender, the inspiratory fraction of oxygen (FIO2) is set from 0.21 to 1.0 in a flow of up to 60 L/min. The gas is heated and humidified with the active humidifier and delivered through the heated circuit (Figure 1). Another major difference between NIV and HFNC is the interface. While interfaces for NIV increase anatomical dead space, those for HFNC actually decrease dead space. Since neither inspiratory push nor expiratory pull is effective in such an open circuit, HFNC cannot actively enhance VT. Even so, it helps COPD patients mainly by decreasing anatomical dead space and secondarily by improving alveolar ventilation.
How much oxygen flow is in a nasal cannula?
Principle setup of high-flow nasal cannula oxygen therapy. An air/oxygen blender, allowing from 0.21 to 1.0 FIO2, generates up to 60 L/min flow. The gas is heated and humidified through an active heated humidifier and delivered via a single-limb heated inspiratory circuit. The patient breathes the adequately heated and humidified medical gas through nasal cannulas with a large diameter.
Is HFNC effective for respiratory failure?
HFNC has been found to be effective for mild to moderate hypoxemic respiratory failure. Sztrymf et al. investigated the efficiency, safety, and outcome of HFNC in ICU patients with ARF [7]. Patients (38 in total) were enrolled when they either required more than 9 L/min of oxygen to achieve a SpO2 > 92% or exhibited persistent signs of respiratory distress. Oxygen flow of about 15 L/min via a face mask was replaced with HFNC of 49 ± 9 L/min. HFNC was associated with significant reductions in breathing frequency, heart rate, dyspnea score, supraclavicular retraction and thoracoabdominal asynchrony, and significant improvement in SpO2. The duration of HFNC was 2.8 ± 1.8 days (max. 7 days), and HFNC was not stopped because of intolerance. In another study, Sztrymf et al. investigated the effects of HFNC on alleviating respiratory distress and ameliorating oxygenation in adult ICU patients with mild to moderate hypoxemic ARF [8]. The etiology of ARF was mainly community-acquired pneumonia and sepsis. Oxygen flow of 15 L/min via a face mask was changed to HFNC of 40 L/min. Under HFNC, breathing frequency decreased and oxygenation improved. After a median delay of 17.5 h of HFNC therapy, 6 of 20 (30%) were subsequently intubated owing to septic shock, gastrointestinal hemorrhage, and worsening pneumonia. In a cardiothoracic ICU, Parke et al. evaluated whether HFNC was better tolerated, with fewer treatment failures, than conventional face mask delivery in patients with mild to moderate hypoxemic respiratory failure [17]. For the HFNC group, flow was 35 L/min, and FIO2were titrated to maintain SpO2at ≥95%: therapy failed for 3 of 29 (10%) in the HFNC group and 12 of 27 (44%) in the conventional group. Roca et al. have also reported good tolerance to HFNC in patients with ARF [9]. HFNC has also been applied in emergency departments, where it was found to alleviate dyspnea and improve oxygenation in patients with hypoxemic ARF [39,40]. These reports have demonstrated how effective HFNC can be as a first-line treatment for ICU patients with ARF.
Is HFNC an effective modality?
Despite these issues, HFNC oxygen therapy is an innovative and effective modality for the early treatment of adults with respiratory failure with diverse underlying diseases.
Does HFNC decrease breathing frequency?
Many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces needs of escalation of respiratory support in patients with diverse underlying diseases.
Why may HFNC be needed?
This can cause a condition called apnea of prematurity (AOP). AOP causes the baby to stop breathing for 15 to 20 seconds or to pause for several seconds. HFNC can help the baby breathe more regularly.
What do I need to know about HFNC use at home?
Healthcare providers will show you how to set up and use the device at home. You will get information on how to clean the parts and how much extra oxygen to keep as a backup. You will also get instructions for using oxygen safely. This includes checking your blood oxygen level regularly with a pulse oximeter.
What is HFNC used for?
This makes it easier to cough up or remove. Keeps the airway open during sleep. HFNC can be used to manage obstructive sleep apnea (OSA). OSA is usually treated with a continuous positive air pressure (CPAP) machine.
How does HFNC work?
HFNC is used to give oxygen at a high rate. The oxygen is delivered through small prongs that sit in the nostrils. The high flow rate makes breathing easier. The lungs do not have to work as hard to get air in and out. It also helps clear carbon dioxide from the airway.
Is a CPAP mask more comfortable than a CPAP?
A CPAP mask may be difficult to wear during sleep. HFNC does not use a mask, so it may be more comfortable than CPAP. Prevents breathing problems before and after a procedure or surgery. For example, breathing problems can develop during intubation.
Can you refuse treatment?
You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.
Evidence-based approaches
igh-flow oxygen therapy allows the accurate delivery of oxygen therapy of up to 100% FiO 2 at a flow rate of up to 60 L/min (system dependent), previously unfeasible via conventional methods of oxygenation (15 L via a non-rebreathable facemask and 6 L via a nasal cannula).
Contraindications of High-flow oxygen therapy
There are no documented absolute contraindications but relative contraindications may include:
What are the positive effects of HFOT?
Positive effects of HFOT. With its warm, humidified constant flow, HFOT improves gas exchange and reduces the work of breathing. 1 2 Other positive effects of HFOT with humidification include: HFOT is commonly used on patients with acute respiratory failure (i.e., hypoxemic respiratory failure). In the hospital setting, these patients are usually ...
What is humidified HFOT used for?
Humidified HFOT has also been used successfully in the treatment of chronic conditions like COPD, bronchiectasis and end-stage cancer, as well as with do-not-intubate patients. 2
What is the maximum flow of an AcuCare cannula?
It is designed to deliver continuous oxygen therapy up to a maximum flow of 60 L/min.
What is HFOT in hospital?
Offers comfort, ease of use and ease of communication to patients. HFOT is commonly used on patients with acute respiratory failure (i.e., hypoxemic respiratory failure). In the hospital setting, these patients are usually in ICU or high dependency wards, requiring assistance with respiration to stabilize breathing and control blood gases.
What is high flow oxygen?
High-flow oxygen therapy is a form of respiratory support used in the hospital where oxygen, often in conjunction with compressed air and humidification, is delivered to a patient at rates of flow higher than that delivered in traditional oxygen therapy . (Traditional oxygen therapy is up to 16 L/min, while HFOT is up to 60 L/min. 1)
What is HFNO fire?
HFNO is a new technology and the reports of two fires described at this early stage of adoption may herald more fires in the future as HFNO gains in popularity. * 16 Practitioners must exercise extreme care to reduce the fire risk.
What is HFNO in anesthesia?
High-Flow Nasal Oxygen (HFNO) administration is a relatively new technique that is used in the intensive care unit (ICU), and increasingly in the operating room (OR). HFNO has become popular in the ICU for management of patients with acute hypoxemic respiratory failure when attempting to avoid intubation or to help after extubation. In some anesthesia contexts, HFNO has been referred to as THRIVE—an abbreviation for Transnasal Humidified Rapid-Insufflation Ventilatory Exchange. Active research is ongoing as to the wider applications of HFNO. This brief current review will discuss the underlying mechanisms of HFNO, its potential use in clinical anesthesia practice, and the risks and benefits of such use. It focuses on the use of HFNO in adult patients, not children.
What are the components of HFNO?
The components of a HFNO system are. An electrically powered high-pressure oxygen/air supply (ideally with a blender to blend air into the gas flow to reduce the FiO 2 if needed) A humidifier capable of fully humidifying the inspired oxygen/air mixture.
What is the flow of oxygen in HFNO?
In contrast, HFNO uses oxygen flows of 50–100 L/M. With this technique, the high flows delivered via the specially designed nasal cannulae now exceed the patient’s IFR. Therefore, there is little entrainment of room air which allows the delivery of a high FiO 2 (95–100%).
How old is too old to use HFNO?
Children under the age of 16. Cases of air-leak syndrome (i.e., pneumothorax) have been reported with HFNO use in children below the age of 16. 8 These were serious events and suggest that research and expert guidance is warranted to determine the safe use of HFNO in children.
Is HFNO a contraindication?
Absolute contraindications to HFNO are. Use of alcohol-based skin preparation solutions in combination with HFNO, which increases the fire risk. Known or suspected skull base fractures, CSF leaks, or any other communication from the nasal to the intracranial space.
What are the elements needed to start a fire?
Figure 1. Illustrates the three elements needed to initiate a fire: oxygen, fuel, ignition source.
What is Optiflow oxygen?
However, this often requires admission to a high dependency unit or intensive care, and is uncomfortable because of the need for a tight fitting mask, as well as being labour intensive and costly. Nasal high flow oxygen (Optiflow™) is a new alternative as it provides warmed humidified oxygen at high flow, and also has been shown to assist breathing and improve recovery. It is comfortable during use and indeed may be more comfortable than standard (dry) oxygen via a facemask (Hudson type) or nasal prongs. It may be administered on a normal ward, however its routine use in high risk patients with lung conditions such as asthma, chronic obstructive pulmonary disease, recent chest infections and heavy smokers has not been tested before.
What is a 6MWT?
they are capable of performing a 6MWT - The 6MWT is a clinical exercise test , and is popular in clinical practice because it aids clinical decision making, and because of the belief that it provides a better estimate of functional capacity than resting cardiorespiratory measurements (24).
What is the standard flow rate for HFNO?
The standard starting flow rate will be 30 L/min, and this will be adjusted up or down between a range of 20-50 L/min with the aim of achieving both patient comfort and a respiratory rate of less than 16 breaths per minute.
What is the oxygen saturation of a COPD patient?
Patients randomised to receive standard oxygen therapy will be fitted with a soft face mask or nasal prongs, and the oxygen flow titrated to provide pulse oxygen saturation of at least 95% (93% for those at risk of hypercapnic respiratory failure such as confirmed COPD patients and morbidly obese patients). The standard oxygen therapy group will have their oxygen gas flow reduced to the minimum level which provides saturations of at least 95% (93% for those at risk of hypercapnic respiratory failure such as patients with confirmed COPD and morbidly obese patients).
How to learn more about a study?
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
How many patients are needed for Optiflow?
The investigators have used data from previous studies to calculate that a total of 74 patients will be needed to take part, in order to evaluate whether high flow nasal oxygen (Optiflow™) leads to reduced length of hospital stay after high risk cardiac surgery compared with usual care oxygen therapy.
Is Optiflow a controlled trial?
A Randomised Controlled Trial of High-flow Nasal Oxygen (Optiflow™) and Standard Oxygen Therapy in High-risk Patients After Cardiac Surgery
How long does it take for a HFNC to improve?
Good responders to HFNC generally show improvements in RR, HR, and work of breathing (WOB) within the first 60–90 minutes [17]. Reductions in apnea and oxygen requirements are also indicative. If the patients showed an increasing oxygen requirement and unchanged or increasing RR, HR, and WOB in this period, adjustment of flow rate and FiO2, another respiratory support and ICU transfer from the ward should be considered. Nonresponders in severe viral bronchiolitis were more likely to have a higher pediatric risk of mortality III scores (PRISM III) [32]. Therefore, careful observation with a pulse oximeter using a central monitoring system is important for the early detection of aggravation.
What is HFNC therapy?
The full name of HFNC is heated humidified HFNC oxygen therapy. Adjustable (FiO221%–100%) heated (34°C–37°C) oxygen with nearly 100% relative humidity can avoid mucosal injury and patient discomfort from cold, dry air. Heated humidification can encourage the clearance of secretions and reduce bronchoconstriction. The basic principle of HFNC is to set a higher oxygen flow than inspiratory demand flow according to the clinical situation. This can lead washout of the upper airways, decreased nasal resistance, and reduced dead space [3]. Current studies revealed that HFNC induces positive airway pressure to lead alveolar recruitment of collapsed lesions and the elevation of functional residual capacity [4,5]. Additionally, HFNC reduces the inflow of ambient air, minimizes the dilution of wanted gas composition, and improves oxygenation [6]. There is no age-dependent differentiation between adults and children in its mechanism of action.
What is a high flow nasal cannula?
High-flow nasal cannula (HFNC) is a relatively safe and effective noninvasive ventilation method that was recently accepted as a treatment option for acute respiratory support before endotracheal intubation or invasive ventilation. The action mechanism of HFNC includes a decrease in nasopharyngeal resistance, washout of dead space, reduction in inflow of ambient air, and an increase in airway pressure. In preterm infants, HFNC can be used to prevent reintubation and initial noninvasive respiratory support after birth. In children, flow level adjustments are crucial considering their maximal efficacy and complications. Randomized controlled studies suggest that HFNC can be used in cases of moderate to severe bronchiolitis upon initial low-flow oxygen failure. HFNC can also reduce intubation and mechanical ventilation in children with respiratory failure. Several observational studies have shown that HFNC can be beneficial in acute asthma and other respiratory distress. Multicenter randomized studies are warranted to determine the feasibility and adherence of HFNC and continuous positive airway pressure in pediatric intensive care units. The development of clinical guidelines for HFNC, including flow settings, indications, and contraindications, device management, efficacy identification, and safety issues are needed, particularly in children.
What is the optimal flow rate for pediatric patients?
Patients younger than 24 months of age tolerated the flow of 1–2 L/kg/min (up to 20 L/min) and 3 L/kg/min. However, patients were uncomfortable with 3 L/kg/min despite the same efficacy [14]. Considering the flow limitation in adults (50–60 L/min), the reasonable flow rate is thought to be 1–2 L/kg/min up to 10 kg in patients, followed by an increase of 0.5 L/kg/min. One study comparing the efficacy of HFNC and CPAP noted no differences in length of stay in the intensive care unit (ICU) and the need for mechanical ventilation between 2 L/kg/min of HFNC and 7 cmH2O of CPAP [15]. Interestingly, there was a large variation of maximal flow rates (L/min) in the different age groups among 67 hospitals [16]. These results showed the importance of comprehensive understanding of the mechanism and optimal flow to ensure better outcomes.
How big should a cannula be?
Cannula size varies by age and body weight. Manufacturers recommend that the cross-sectional area of the cannula be no more than 50% that of the nares because of the risk of unexpected elevations in airway pressure and the following risk of air leak. That means that the appropriate outer diameter of the cannula is no more than two-thirds that of the nares. Recommended flow settings and cannula sizes for pediatric patients are summarized in Table 1.
Is HFNC better than oxygen?
In adult studies of acute respiratory failure, HFNC reduced the rates of intubation, mechanical ventilation, and escalation of respiratory support compared to conventional oxygen therapy but showed no better outcomes than noninvasive ventilation [24]. Acute respiratory failure due to various etiology in children might be treated with HFNC before other respiratory supports according to patient severity and clinical settings. HFNC improved oxygenation by reducing HR in CPAP-intolerant children (N=10) with obstructive sleep apnea syndrome (OSAS) [25]. Moreover, another study reported improvements in the apneahypopnea index and nadir oxygen saturation in 5 patients with HFNC [26]. These studies suggested that HFNC could warrant further studies and consideration as alternative OSAS therapies. HFNC therapy improved the respiration rate of pediatric patients with postextubation acute respiratory failure after cardiac surgery [27]. HFNC showed a lower failure rate after extubation compared with that of the conventional oxygen therapy group in the ICU [28].
Is HFNC considered for respiratory distress?
In the ED, HFNC could be considered for patients with respiratory distress not requiring immediate endotracheal intubation [23].
How much oxygen is in a nasal cannula?
Nasal cannulae used for medical gas delivery are usually limited to delivery of 1–6 liters of flow per minute. The percent oxygen inhaled by the patient (FiO 2 ), usually ranges roughly 24–35% as the pure oxygen delivered from the cannula is diluted by entrainment of ambient air (21% oxygen). Flow rates for delivery of oxygen using typical nasal cannula are limited because medical oxygen is anhydrous, and when delivered from a pressurized source the gas cools as it expands with the drop to atmospheric pressure. Delivery of cold dry gas is irritating to the respiratory mucosa, can cause drying and bleeding of the nasal mucosa and can increase metabolic demand by cooling the body.
What is HHHF in medical terms?
Heated humidified high-flow ( HHHF) therapy, often also high flow nasal cannula (e) ( HFNC) or high flow nasal oxygen ( HFNO ), is a type of respiratory support method that delivers a high flow (liters per minute) of medical gas to a patient through an interface ( nasal cannulae) intended to create a wash-out of the upper airway. The applied gas is heated to best match human body temperature (37 °C) and humidified targeting ideal body saturation vapor pressure. It is used in acute and chronic breathing problems, and is a suitable choice for treatment of patients with severe or critical COVID-19.
What is a nasal cannula?
Through a nasal cannula a high-flow system delivers flows that approach (and can meet) total respiratory demand. This flow, being delivered though a small diameter delivery system and small-bore nasal cannula allows the flow that would traditionally move slowly through the upper airway to move quickly and maintain a constant stream of fresh gas which effectively washes out upper airway dead space.
Why is HFT important?
HFT is useful in the treatment of sleep apnea.
How is oxygenation achieved?
Oxygenation is achieved by providing an increased FiO 2 in the air flow to the patient. The constant flush of the upper airway creates a reservoir that reduces room-air entrainment to such an amount that it becomes a true fraction of inspired oxygen as set by the device.
When was the nasal cannula invented?
Vapotherm introduced the concept of heated humidified high flow therapy via nasal cannula in 1999 after being originally developed for use in race horses.
Why is HFT heated?
The gas is heated and humidified to condition the gas as increased flows would be detrimental to tissue if left dry and cool. HFT, a source of oxygen is usually blended with compressed air. Hospitals usually have 50 psi (350 kPa) compressed oxygen and air available for therapeutic use.
