Five international experts discuss HFNC therapy online webinar

Five international experts discuss HFNC therapy online webinar

High flow nasal cannula therapy: Daily practice tips - Experts On Air | Hamilton Medical

High flow nasal cannula therapy:

In our first webinar series, five international experts discussed various aspects of treating patients with high flow nasal cannula therapy (HFNC) (Also known as high flow oxygen therapy. This terminology can be used interchangeably with high flow nasal cannula therapyA​). They looked at some of the challenges you might face and offered their tips and tricks for best practice to improve patient outcomes.

Right patient, right treatment, right time?How to use HFOT guidelines

Sharon Einav and Tommaso Mauri.

Before initiating HFNC 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.

How to optimize HFNC therapy settings.Input from physiological studies

Tommaso Mauri and Jens Bräunlich.

In order to improve physiology and outcomes of patients supported by HFNC, 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. We focused on how to optimize HFNC this physiology-based approach.

How to monitor patients.During nasal HFNC therapy

Oriol Roca and Sharon Einav.

To better understand the progress of nasal high flow nasal cannula therapy 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.

Intubation in hypoxemic respiratory failure:Does time matter?

Jean-Damien Ricard and 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 HFNC therapy and which parameters should be taken into consideration.

Jens Bräunlich and Tommaso Mauri.

The latest studies indicate that HFNC 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.

Jean-Damien Ricard and Oriol Roca.

The COVID-19 pandemic has seen HFNC 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.

Ask the experts.Questions and answers

Q&A 1.Right patient, right treatment, right time? How to use HFOT guidelines

There is currently no known protocol for congenital heart surgery

There is no formal protocol for weaning. (See the next webinar on February 24 about optimizing HFOT settings).

Data is clear on the benefit of CPAP, there is not enough literature on HFNO.

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.

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.

There are three 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. Published 2021 Oct 28. doi:10.1186

s13561-021-00339-71​,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. doi:10.1080

03007995.2021.19433422​,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. doi:10.1002

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. Published 2021 Jun 18. doi:10.2147

montior the patient (no alarms).

Mainly delayed intubation; possible P-SILI as well.

Not at all. The advantage of HFO 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.

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. Published 2021 Dec 8. doi:10.1186

s13054-021-03784-25​: “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 Patients with COVID-19. Am J Respir Crit Care Med. 2022;205(4):431-439. doi:10.1164

rccm.202109-2163OC6​: “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

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. doi:10.1001

jama.2022.00287​: “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.”

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).

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).

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

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.

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. doi:10.1093

We alternate based on the patients tolerance and response.

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.

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.

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

Q&A 2.How to optimize HFOT settings - Input from physiological studies

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.

The paper mentioned in my talk by Pinkham et al. is very recent and confirms values between 2 and 5 cmH2O (Pinkham M, Tatkov S. Effect of flow and cannula size on generated pressure during nasal high flow. Crit Care. 2020;24(1):248. Published 2020 May 24. doi:10.1186

I would be careful, for the study in Crit Care 2020 on flows > 60 l

min we used 2 humidifiers.

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

Aerosol shouldn’t be an issue, HFNC can even grant improved delivery to the distal airways, seeReminiac F, Vecellio L, Bodet-Contentin L, et al. Nasal high-flow bronchodilator nebulization: a randomized cross-over study. Ann Intensive Care. 2018;8(1):128. Published 2018 Dec 20. doi:10.1186

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.

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.

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

Q&A 3.How to monitor patients during nasal HFOT

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.

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.

(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

There is no specific timeframe for expected improvement. However, it is true that some thresholds of differe