Experts On Air

Past events: Webinar series on high flow therapy

Did you miss one of the webinars on high flow therapy? Below you find links to the recordings and some answers to questions not addressed during the webinar.

Past events: Series 1 - High flow therapy

In our first webinar series, five international experts discussed various aspects of treating patients with high flow oxygen therapy. They looked at some of the challenges you might face and offered their tips and tricks for best practice to improve patient outcomes.

High flow therapy #1

February 10, 2022; 15:00 (CET)
Right patient, right treatment, right time? How to use HFOT guidelines 
Speaker: Sharon Einav; Interviewer: Tommaso Mauri 

Before initiating high flow oxygen therapy, we need to identify the patient’s criteria and adapt treatment based on clinical guidelines. This webinar looked at the different types of patients and how they can benefit from this therapy. If there was no time for your question during the event, see some more answers below.

Watch the recording

High flow therapy #2

February 24, 2022; 15:00 (CET)
How to optimize HFOT settings - Input from physiological studies 
Speaker: Tommaso Mauri; Interviewer: Jens Bräunlich 

In order to improve physiology and outcomes of patients supported by high flow oxygen therapy, it is crucial to adjust the flow rate, FiO2, temperature, and cannula size based on target physiological variables such as respiratory effort, ROX index, respiratory rate, etc., as well as on patient comfort. In this webinar, we focused on how to optimize the high flow therapy through this physiology-based approach. If your question was not answered during the webinar, see the additional answers below.

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High flow therapy #3

March 17, 2022; 15:00 (CET)
How to monitor patients during nasal HFOT 
Speaker: Oriol Roca; Interviewer: Sharon Einav

To better understand the progress of nasal HFOT, it is essential to monitor the patient's respiratory parameters such as oxygenation and RR. In this session, we covered different aspects of respiratory monitoring and explain how they could be used at the bedside. If your question was not answered during the webinar, see the additional answers below.

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High flow therapy #4

March 31, 2022; 15:00 (CET)
Intubation in hypoxemic respiratory failure: Does time matter? 
Speaker: Jean-Damien Ricard; Interviewer: Tommaso Mauri

The point in time at which a critically ill patient is intubated can play an important role in their survival, especially in those with hypoxemic respiratory failure. In this webinar, we talked about when to intubate patients undergoing high flow oxygen therapy and which parameters should be taken into consideration. If your question was not answered during the webinar, see the additional answers below.

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High flow therapy #5

April 14, 2022; 15:00 (CET)
HFOT in hypercapnic respiratory failure 
Speaker: Jens Bräunlich; Interviewer: Tommaso Mauri

The latest studies indicate that HFOT may have beneficial effects on patients with hypercapnia. In this webinar, we reviewed the effects this therapy may have on these patients and how to approach their treatment. Almost all the questions were answered during the webinar, but there are a couple of additional answers below.

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High flow therapy #6

May 5, 2022; 15:00 (CET)
HFOT outside of critical care 
Speaker: Jean-Damien Ricard; Interviewer: Oriol Roca

The COVID-19 pandemic has seen high flow oxygen therapy become more and more relevant in various departments, including emergency care, pediatrics, and general patient wards. In this webinar, we looked at where this therapy could be initiated to achieve better patient outcomes. Almost all the questions were answered during the webinar, but there are a couple of additional answers below.

Watch the recording

Q&As - High flow therapy #1

Below you can find the speaker's responses to questions asked by participants that were not addressed during the webinar. If your question was in relation to weaning, see the upcoming webinar on February 24 about optimizing HFOT settings. 

  • I would like to hear about use of HFO and the weaning from non invasive mechanical ventilation. Is there a protocol for congenital heart surgery?

    • There is currently no known protocol for congenital heart surgery.
  • I would like to know about limitations of HFNC and patient weaning on this mode?

    • There is no formal protocol for weaning. (See the next webinar on February 24 about optimizing HFOT settings).
  • What is the role of HFNO in heart failure?

    • Data is clear on the benefit of CPAP, there is not enough literature on HFNO.
  • (a) In which postoperative patients, you would recommend use of HFNC after extubation? (b) When compared to NIV? (c) And which patients you would suggest use of NIV?

    • (a) In high risk/obese patients particularly after chest surgery and abdominal surgery. Also consider ENT if there are secretions. (b) There could be a possible issue with pressure on surgical sutures with NIV if it was gastric surgery. (c)  In failed HFNO, heart failure patients. You could also alternate HFNO with NIV. 
  • Should HFNC be used to prevent extubation failure also in non-surgical patients?

    • Prevention : HFNC is good for comfort and maybe shortened stays. Treatment:  This is unclear (not enough patients). NIV shows benefit but there is not enough head-to-head data.
  • Is there any analysis of cost of care and cost-effectiveness of different methods ?

    • There are two papers showing the cost-effectiveness of HFNC. It is obviously not for indiscriminate use.  For pediatrics, there is also literature justifying the use of HFNO for bronchiolitis.  

      Buendía JA, Acuña-Cordero R, Rodriguez-Martinez CE. The cost-utility of early use of high-flow nasal cannula in bronchiolitis. Health Econ Rev. 2021;11(1):41.  

      Buendía JA, Acuña-Cordero R, Rodriguez-Martinez CE. Budget impact analysis of high-flow nasal cannula for infant bronchiolitis: the Colombian National Health System perspective. Curr Med Res Opin. 2021;37(9):1627-1632. 

      Heikkilä P, Forma L, Korppi M. High-flow oxygen therapy is more cost-effective for bronchiolitis than standard treatment-A decision-tree analysis. Pediatr Pulmonol. 2016;51(12):1393-1402. 

      There is also some cost-utility work on HFNO for COPD use at home which appears quite convincing.

      Sørensen SS, Storgaard LH, Weinreich UM. Cost-Effectiveness of Domiciliary High Flow Nasal Cannula Treatment in COPD Patients with Chronic Respiratory Failure. Clinicoecon Outcomes Res. 2021;13:553-564. 

  • What are the indications and contradictions of HFOT?

    • Contraindications: Patient not awake / nobody to see/montior the patient (no alarms).
  • What are the adverse effects of HFOT?

    • Mainly delayed intubation; possible P-SILI as well.
  • Should all patients requiring supplemental oxygen supply be considered for HFOT as their initial therapy?

    • Not at all. The advantage of HFNO is in the high flows. Hence, if there is no respiratory distress (i.e., low flows) and supplementation up to an FiO2 of 0.5-0.6 suffices, there is no need.
  • How effective is HFOT for COVID-19 patients?

    • There are no RCTs but there are several interesting studies thus far:

      COVID-ICU group, for the REVA network, COVID-ICU investigators. Benefits and risks of noninvasive oxygenation strategy in COVID-19: a multicenter, prospective cohort study (COVID-ICU) in 137 hospitals. Crit Care. 2021;25(1):421.  
      “In patients with COVID-19, HFNC was associated with a reduction in oxygenation failure without improvement in 90-day mortality, whereas NIV was associated with a higher mortality in these patients. “

      Ranieri VM, Tonetti T, Navalesi P, et al. High Flow Nasal Oxygen for Severe Hypoxemia: Oxygenation Response and Outcome in COVID-19 Patients. Am J Respir Crit Care Med. 2021;10.1164/rccm.202109-2163OC. 
      “We analyzed 184 and 131 patients receiving HFNO or NIV, respectively. 112 HFNO, and 69 NIV patients transitioned to IMV. 104 (92.9%) HFNO patients and 66 (95.7%) NIV patients continued to have PaO2/FiO2 ≤300 under IMV…. Overall mortality was 19.0% (35/184) and 24.4% (32/131) for HFNO and NIV, respectively (p=0.2479).”

      Perkins GD, Ji C, Connolly BA, et al. Effect of Noninvasive Respiratory Strategies on Intubation or Mortality Among Patients With Acute Hypoxemic Respiratory Failure and COVID-19: The RECOVERY-RS Randomized Clinical Trial. JAMA. 2022;327(6):546-558. 
      “Among patients with acute hypoxemic respiratory failure due to COVID-19, an initial strategy of CPAP significantly reduced the risk of tracheal intubation or mortality compared with conventional oxygen therapy, but there was no significant difference between an initial strategy of HFNO compared with conventional oxygen therapy. The study may have been underpowered for the comparison of HFNO vs conventional oxygen therapy.”
      This may be better than immediately intubating these patients…

  • Would you recommend use of high flow nasal cannula for the early treatment of hypoxemic respiratory failure due to COVID-19?

    • Definitely yes, although the literature is still not sufficiently strong. There are no RCTs but there are several interesting studies thus far (see answer to previous question).

  • Do you have experience with Nasal High Flow Oxygen and patients with a tracheostomy tube or are you aware of a problem that the tracheostomy tube can clog when used with NHFO? We have seen an increase in these problems.

    • Yes, we use a specific connector for tracheostomy. Only in monitored areas. Not for patients who need suction more than 2 or more times each nursing shift (>twice in 8 hours).  

  • In which patients with hypoxemic ARF you would recommend the use of HFNC over NIV or COT, as first-line treatment?

    • Over COT and before NIV for all patients except heart failure.

  • How to identify patients with hypoxemic ARF that would most likely to benefit from HFNC (over NIV and COT)?

    • Possibly looking forward there may be ways to identify these patients based on their aeration distributions (CT) and WOB (EiT). We are not there yet.

  • Is there any category of hypoxemic ARF patients for whom you may prefer using NIV (especially helmet CPAP)?

    • Helmet is the interface, not the mode of ventilation. Use of a helmet interface requires experience. We use it for patients who are cooperative and alternate it with HFNO since it limits communication and feeding.  

      In terms of mode, BiPAP definitely first line only for pulmonary edema (heart failure). An interesting paper on helmet vs. HFNO for heart failure  (single center about 200 patients):
      Osman A, Via G, Sallehuddin RM, et al. Helmet continuous positive airway pressure vs. high flow nasal cannula oxygen in acute cardiogenic pulmonary oedema: a randomized controlled trial. Eur Heart J Acute Cardiovasc Care. 2021;10(10):1103-1111. 

      For COVID: 110 patients:
      Grieco DL, Menga LS, Cesarano M, et al. Effect of Helmet Noninvasive Ventilation vs High-Flow Nasal Oxygen on Days Free of Respiratory Support in Patients With COVID-19 and Moderate to Severe Hypoxemic Respiratory Failure: The HENIVOT Randomized Clinical Trial. JAMA. 2021 May 4;325(17):1731-1743. 
      Among patients with COVID-19 and moderate to severe hypoxemia, treatment with helmet noninvasive ventilation, compared with high-flow nasal oxygen, resulted in no significant difference in the number of days free of respiratory support within 28 days.

  • Helmet CPAP vs HFNC for COVID-19. What would you recommend? Would you adopt a different strategy to different patients? If yes, based on what?

    • We alternate based on the patients tolerance and response.

  • Your treatment option for patients with cardiogenic pulmonary edema? HFNC or CPAP or NIV?

    • BiPAP definitely.

  • There seems to be no evidence supporting the use of high flow nasal cannula for pre-oxygenation (before intubation), but I have positive experience. Would you recommend it?

    • The problem is that mean apnea times in the studies for the metaanalysis were <2 minutes and even <1 in critical care patients. Also, most patients included in these studies were not with severe hypoxia, no data on difficult intubations, not enough on obesity (one study) and not on preganacy. So overall I agree with your clinical impression and we use it during intubations of patients with hypoxemia in our ICU.

  • Is there any benefit of using high flow nasal cannula in preventing self-inflicted lung injury?

    • There may be P-SILI with HFNO as well but this is vey diffucult to measure clinically. There is direct evidence of this in only neonatal cases with baro/volutrauma but we must assume the possibility exists in adults too.

  • Regarding hypoxemic respiratory failure patients, is there an optimal flow to start the treatment? How should the flow titration be done in this patients?

    • At least 30 liters per minute. (See the upcoming webinar on optimizing HFOT settings on February 24.) 

Q&As - High flow therapy #2

Below you can find the speaker's responses to questions asked by participants that were not addressed during the webinar. These include some of the questions asked about weaning during the first webinar.

  • Know about limitations of HFNC and how know the patient weaning on this mode?

    • Weaning from HFNC should be gradual as this is a potent non invasive support. FiO2 could be the first setting to decrease, while flow can be safely reduced after FiO2 becomes <50%. When FiO2 is <40% with flow <40 l/min, transition to standard oxygen, for example to discharge the patient from the ICU. This could be attempted with 2 hours of close monitoring.
  • Are there weaning guidelines for hfnc?

    • See above.
  • Is humidification during HFOT with a flow of 100 l/min sufficient?

    • I would be careful, for the study in Crit Care 2020 on flows > 60 l/min we used 2 humidifiers. 
  • How to properly wean off from HFNC?

    • See above.
  • If patients have nasogastric tube, how can we optimize the usage of HFNC? 

    • We do use HFNC with NGT, usually smaller cannula, being careful of accurate positioning and checking from time to time. 

  • I have seen high flow connected to a mask instead of the nasal prongs, for patients that are considered ‘mouth breathers’. I think the tube was connected to the nebuliser mask, with the nebuliser removed and the tubing where the nebuliser would normally go… would this reduce the washout of co2? (Editor's note: Use of  a mask and HFOT in order to increase FiO2 was discussed during the webinar.)

    • Yes, if the high flow is connected to a mask you just give a lot of oxygen, probably lose both PEEP effect (no occlusion of the nares) and CO2 washout (no direct flow in the upper airways), I would avoid that.
  • Is CO2 clearence affected with open mounth (via Venturi effect)?

    • No, CO2 clearance is not affected as long as there is a circulation of gas, open mouth and venturi effect may reduce tha alveolar FiO2 and the PEEP effect, determining worsening oxygenation.
  • You said that you assess the PEEP effect by measuring EELV; how do you measure EELV on a patient on HFNC?

    • We normally use EIT by continuous monitoring of end-expiratory impedance before and after start of HFNC.

Q&As - High flow therapy #3

Below you can find the speaker's responses to questions asked by participants that were not addressed during the webinar. 

  • Could you give some information about OSI monitorization? How can we interpret it clinically?

    • OSI is the oxygenation saturation index. Is is normally defined as [Fio2 × mean airway pressure × 100)/oxygen saturation by pulse oximetry (Spo2)] and predicts outcomes of mechanically ventilated patients. In the case of HFNC patients, MAP may be estimated by the level of flow delivered, but no data is available about its utility.
  • What is the earliest indicator for you that treatment with HFNC is working? And how long do you need to wait to understand if you have selected the right flow? 

    • There is probably no single variable that reflects the response to the treatment. I think that different things happen when the patient is doing well: oxygenation improvement, decrease in respiratory rate, relief in dyspnea feeling… Regarding the right flow, we know that most of the effects are flow-dependent and, therefore, when we start the treatment in paitents with acute hypoxemic respiratory failure, we try to use the highest tolerated flow. However, we can't start with 60Lpm as the patient does not tolerate it. So we start with 40Lpm and once the patient is used to receiving this amount of flow, we can progressively increase up to 60Lpm. This increase can usually be made in the first 30 minutes of treatment.
  • What are the different aspects of respiratory monitoring?

    • (Editor's note: "aspects" has been understood as "variables" for the purposes of this answer) Clinical examination, respiratory rate, use of accessory muscles, thoraco-abdominal asynchrony, SpO2, FiO2
  • After starting nasal HFOT, when I can expect the patient condition to improve (after how many minutes)?

    • There is no specific timeframe for expected improvement. However, it is true that some thresholds of different variables have been described as predictors of HFNC failure at different time-points.  
  • Which indicators or parameters you can use to understand if the patient effort is excessive (without Peso measurements)?

    • The use of accessory muscles suggests that the inspiratory effort is excessive. Similarly, low PaCO2 or a negative swing in CVP could also suggest the same. (Please also see the second webinar for an answer to this question.)
  • How long do you wait before changing the flow if the patient is not responding? 

    • I do not wait. If the patient is not responding to the treatment, I try to increase the flow up to the maximum tolerated. And if the patient is still not responding, one would need to escalate the treatment. 

  • What about the timing of intubation? How does it influence the outcomes?

    • The evidence is sometimes controversial because the criteria for intubation may vary a lot between different countries, hospitals or even doctors in the same ICU. Thus, some studies compared early versus delayed intubation taking the time of ICU admission as moment 0. The majority of them have shown that earlier intubation is associated with better outcomes. In other words, delayed intubation may be associated with increased mortality. 
  • How do you apply the ROX index in your clinical practice?

    • My suggestion would be not to base the decision of intubating a patient based only on a number. The clinical examination of the patient is extremely important. The ROX may help you to decide if the patient is doing well or not, as you can repeat the measurement several times. The benefit of the ROX is that it is based on physiological variables that determine the outcome (need for intubation). We proposed an algorithm that may help in a review in ICM with Jean-Damien Ricard in 2020 that we are now testing in a RCT.
  • Why or when would you place an arterial line on a patient on High Flow O2 therapy?

    • In our clinical practice we rarely do it. There is a good correlation between SpO2 and PaO2 if you keep the SpO2 < 98%. 
  • How about HFT via tracheostomy?

    • These patients usually need lower flows and benefit more from active humidification that improves secretion clearance. But I would base my decisions in the same way as for HFNC patients. 
  • For tracheostomy patients, on what basis can I reduce flow?

    • As commented before, I would never make a decision based on just a number. I think that the ROX value should be combined with the clinical examination of the patient.

Q&As - High flow therapy #4

Below you can find the speaker's responses to questions asked by participants that were not addressed or only answered in part during the webinar. 

  • How to effective is highflow in order to prevent intubation?

    • Many observational studies have suggested that NHF prevents intubation. The clinical impression was unequivocally demonstrated in a large randomized trial (1). In this study, patients at greater risk of intubation (i.e., those with PaO2/FiO2 below 200) and who received NHF were significantly less intubated than those who received either NIV or standard oxygen. More recently, several studies performed in Covid-related ARDS have confirmed the prevention of intubation with the use of NHF (2, 3). Of note, the data is less conclusive in patients with hematological or oncological disorders.
      1. Frat JP, Thille AW, Mercat A, et al. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med. 2015 Jun 4;372(23):2185-96.  
      2. COVID-ICU group, for the REVA network, COVID-ICU investigators. Benefits and risks of noninvasive oxygenation strategy in COVID-19: a multicenter, prospective cohort study (COVID-ICU) in 137 hospitals. Crit Care 25, 421 (2021). 
      3. Ospina-Tascón GA, Calderón-Tapia LE, García AF, et al. Effect of High-Flow Oxygen Therapy vs Conventional Oxygen Therapy on Invasive Mechanical Ventilation and Clinical Recovery in Patients With Severe COVID-19: A Randomized Clinical Trial. JAMA. 2021 Dec 7;326(21):2161-2171. Erratum in: JAMA. 2022 Mar 15;327(11):1093.
  • Is high flow oxygen and further invasive ventilation of any help for patient of age beyond 65 years considering lots of congestion and lung damage due to COVID 19 pneumonia? 

    • If the question is interpreted as "Is it reasonable to start NHF and perhaps escalate to invasive ventilation in a patient beyond 65 years", the answer is yes, but patients and family must be informed that the prognosis is much less favorable than in younger patients. My bias is that intubation should be discussed on an individual basis above 70-75, depending on the presence of comorbodities and the fitness of the patient before being infected by Covid.
  • Would you use HFNC in patient with severe COVID19-related lung involvement (>80% ground glass) regardless of ROX >5?

    • Yes, for at least two reasons. First, although there is - at a cohort level - a relationship between the importance of lung involvement and outcome, on an individual basis, we have sometimes had very rapid recovery despite an initial unfavorable radiological assessment. Second, the radiological phenotype also plays a role (we had the impression that very diffuse ground glass was less "bad" than consolidation display). And finally, even if the patient is at high risk of intubation, NHF can be initiated and will help preoxygenate the patient, and will serve as apneic oxygenation during laryngoscopy.  
  • Would you suggest trying with 100 l/min? What is your clinical experience?

    • I don't yet have any personal experience with 100 l/min. My bias is that because there is a linear relationship between flow and both positive pressure and deadspace washout, this suggests that beneficial effects of NHF are more important at 100 l/min than at 60. Obviously, the question of tolerance is a key issue. We need more data on the tolerance of these very high flows.
  • Regarding extubating, what are the parameters that I should evaluate for a safe extubation? 

    • This is a vast question and whole consensus conferences have been dedicated to this unique question. Bear in mind several facts: 1) there is no 100%-sure test or group of parameters that predict safe extubation; 2) reintubation will occur in 10%-20% of patients; 3) unplanned extubation does not systematically lead to reintubation (only 40% approx.). That means we as clinicians must stay very humble as to our capacity to predict extubation outcome. Always perform either a T-piece trial or minimal pressure support spontaneous breathing trial. When to start these trials? Partial or complete resolution of the cause that led to intubation. Hemodynamic stability without vasopressors, FiO2 < 40%, PEEP < 5, no or little neurological and cognitive impairment, appropriate cough, no or little muscle weakness. 

Q&As - High flow therapy #5

Below you can find the speaker's responses to questions asked by participants that were not addressed or only answered in part during the webinar. 

  • What could be the reason for a reduced exacerbation rate in COPD patients treated with HFNC during sleep? 

    • There could be two possible reasons: 1. It could be an optimized ventilation and endobronchial humidity, which leads to reduced triggering of an ECOPD 2. Prevention of symptoms worsening in the case of exacerbation onset.
  • Would you recommend to manufacturers to create a single cannula?

    • After some more clinical studies about efficiency this could be the next step to optimize NHF therapy.   
  • Comment from participant: Note we had a lot of experience with masks/helmet CPAP NIV and started with Nasal High flow 12 years ago, we observed that younger employees in particular no longer had this high NIV / CPAP experience or unfortunately this knowledge is lost because we are with Nasal High Flow have had very good experiences, so that COPD patients in particular rarely needed NIV masks. Oxygenation problem are further treated with mask with helmet/NIV.

    • We have the same experience.

Q&As - High flow therapy #6

Below you can find the speaker's responses to questions asked by participants that were not addressed or only answered in part during the webinar. 

  • HF in ED without negative pressure room? 

    • In my ICU, we performed nasal high flow in Covid-19 patients throughout all the consecutive surges in rooms without negative pressure without experiencing staff contamination. So the answer, in my opinion, is yes, nasal high flow can be performed in a room without negative pressure, provided staff is properly equipped with PPE.
  • What safety parameters to observe to keep HFOT out of the ICU?

    • (Editor's note: This question was interpreted as "What safety parameters should be observed when using HFOT outside of the ICU?"). Tthere is no definite answer to that question, because it depends on how far from the ICU nasal high flow is performed, how well the staff is trained to perform and monitor nasal high flow in patients with acute respiratory failure, if these patients will have continuous measurment of SpO2 or not, etc. Having said this, I believe FiO2 should be limited, and not exceed 60%; SpO2 should not be below 92-94% ; respiratory rate no greater than 25-28. if patients are out of one of these targets, then an ICU physician should be called to assess these patients  
  • Can HFOT be used in transportation / medical evacuations?

    • I have no personal data or experience. My bias is that if there is no possiblity of electric supply, then it will be problematic to not have any humidification. If an external battery was available and it covered the entire flight time, then I would see no "technical" reasons why such a device could not be operated during a helictopter flight  (Editor's note: To our knowledge, there is currently no humidification device available that is approved for transport.)
  • From what age can the Rox index be used as an indicator of success or failure of HFOT? Can it be used in children?

  • Do you have any experince with patients with bronchiolitis?

The contents of this page are for informational purposes only and are not intended to be a substitute for professional training or for standard treatment guidelines in your facility. The responses to the questions on this page were prepared by the respective webinar's speaker;  any recommendations made here with respect to clinical practice or the use of specific products, technology, or therapies represent the personal opinion of the speaker only, and may not be considered as official recommendations made by Hamilton Medical AG. Hamilton Medical AG provides no warranty with respect to the information contained ion this page and reliance on any part of this information is solely at your own risk.