Category: Letters

High flow nasal cannula: a new option in treatment of acute hypoxemic respiratory failure

A. Garramone, O. Spagnolello, E. Bresciani

Medicina d’Emergenza ed Urgenza 
Università La Sapienza Roma
High flow nasal cannula oxygen therapy (HFNC) is an emerging technique employed in the management of respiratory failures. HFNC provides through non occluding nasal prongs, a high flow heated and humidified medical gas, with a FiO2 ranging from 0.21 to 1.0. 
A high flow medical gas (up to 60 L/minute) is related at least to three main effects: the anatomical dead space wash out, the “PEEP effect” and finally a more predictable FiO2. A continuous wash out of the nasopharingeal dead space allows a higher fraction of minute ventilation to contribute to gas exchange, therefore improving ventilation and efficacy of oxygen therapy. 1,2 Although HFNC is an open system, a “PEEP effect” is probably related to the expiratory resistence produced by the high gas flow. The PEEP effect is linearly correlated with the increment of gas flow and seems larger when patients breath with their mouth closed.3,4 The gas flow delivered with HFNC habitually exceeds the peak inspiratory flow of dispnoic patients, determining a minor entrainment of room air and consequently a minor dilution of inhaled FiO2.5,6,7 Moreover, delivering a gas flow brought to body temperature and saturated with water seems having a number of favorable physiological effects. It improves mucociliary clearance8,9 and it reduces the work of breathing, avoiding broncho-constricting effect of cold-dry gas. At the end it enhances the comfort of patient reducing upper airways dryness10.
One of the major feature of HFNC is the great tolerance and grade of comfort of patients compared to both conventional oxygen therapy (COT)11 and NIV12. In the last few years several studies investigated clinical applications of HFNC: acute hypoxemic respiratory failure (AhRF)13,14,15, hypercapnic non acidotic respiratory failure16, OSAS17, pre oxygenation before orotracheal intubation (IOT)18,19 and peri-procedural oxygenation20. Among them, the most promising seems to be the treatment of de novo AhRF; favorable evidences have been reported even in ARDS due to influenza H1N121, 22.
Currently, most of the available data come from Intensive Care Units (ICUs) even though successful results and good compliance among physicians have been reported in the Emergency Department too23, 24.
Despite the majority of studies have compared HFNC to COT, the advantage of the former has never been assessed so far.
However, some authors claim that HFNC may be superior in terms of IOT rate even if no difference was found in relation to mortality25. On the other hand, other works suggest that no difference exists between HFNC and COT even with respect to the IOT rate26.
Few works comparing HFNC to NIV in AhRF are currently available: only three of them are multicentric randomized clinical trials (RCT)27, 28, 29. The FLORALI is the only RCT conducted within several ICUs, randomly assigning HFNC, COT or bilevel NIV up to 300 patients with AhRF. Although no difference was found relatively to the proportion of patient intubated, except in the PaO2/FiO2 < 200 mmHg sub-group post hoc analysis27, a significant survival benefit has been reported among patients who were receiving HFNC therapy.
According to current scientific evidence, there are not enough data to consider HFNC superior than NIV or COT in the treatment of AhRF. Therefore it is not possible to give any univocal recommendation on the use of one specific technique31. However, some authors believe that HFNC should be considered as the first-line treatment option prior to NIV in AhRF management30, since such strategies could be similar to NIV in terms of IOT rate but is definitively more tolerated 12. Hence, others multicentric RCT are required, but certainly HFNC may assume an important role in treatment of de novo AhRF on the future.
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  2. Ravenscraft SA , Shapiro RS , Nahum A , et al . Tracheal gas insuffl ation:catheter eff ectiveness determined by expiratory fl ush volume . Am J Respir Crit Care Med. 1996;153 (6): 1817 - 1824.
  3. Groves N , Tobin A. High flow nasal oxygen generates positive airway pressure in adult volunteers . Aust Crit Care. 2007; 20(4):126 - 131.
  4. Rachael L Parke RN MHSc, Michelle L Eccleston RN, and Shay P McGuinness MB ChB.The Effects of Flow on Airway Pressure During Nasal High-Flow Oxygen Therapy. Respir Care.2011;56 (8):1151 – 1155.
  5. Sim MAB , Dean P , Kinsella J , Black R , Carter R , Hughes M . Performance of oxygen delivery devices when the breathing pattern of respiratory failure is simulated. Anaesthesia. 2008;63(9):938 – 940.
  6. Ritchie JE , Williams AB , Gerard C , Hockey H . Evaluation of humidifi ed nasal high-flow oxygen system, using oxygraphy, capnography and measurement of upper airways pressure. Anesth Intensive Care. 2011:39(6):1103 - 1110.
  7. Wagstaff TAJ , Soni N. Performance of six types of oxygen delivery devices at varying respiratory rates. Anaesthesia. 2007; 62(5): 492- 503.
  8. Salah B, Dinh Xuan AT, Fouilladieu JL, Lockhart A, Regnard J. Nasal mucociliary transport in healthy subjects is slower when breathing dry air. Eur Respir J. 1988;1(9):852–5.
  9. Hasani A , Chapman TH , McCool D , Smith RE , Dilworth JP , Agnew JE . Domiciliary humidifi cation improves lung mucociliary clearance in patients with bronchiectasis. Chron Respir Dis. 2008;5(2): 81-86
  10. Giulia Spoletini , MD ; Mona Alotaibi , MD ; Francesco Blasi , MD ; and Nicholas S. Hill , MD, FCCP. Heated Humidifi ed High-Flow Nasal Oxygen in Adults Mechanisms of Action and Clinical Implications. CHEST. 2015; 148(1): 253- 261
  11. Roca O , Riera J , Torres F , Masclans JR . High-flow oxygen therapy in acute respiratory failure . Respir Care. 2010; 55 (4): 408 - 413.
  12. Monro-Somerville T, Sim M, Ruddy J, et al: The Effect of High-Flow Nasal Cannula Oxygen Therapy on Mortality and Intubation Rate in Acute Respiratory Failure: A Systematic Review and Meta-Analysis. Crit Care Med. 2017. 45(4):e449- e456.
  13. Sztrymf B, Messika J, Mayot T, Lenglet H, Dreyfuss D, Ricard J-D. Impact of high-flow nasal cannula oxygen therapy on intensive care unit patients with acute respiratory failure: a prospective observational study. J Crit Care.2012;27:324.e9–13.
  14. Roca O, Riera J, Torres F, Masclans JR. High-flow oxygen therapy in acute respiratory failure. Respir Care. 2010;55:408–13.
  15. Carratalá Perales JM, Llorens P, Brouzet B, Albert Jiménez AR, Fernández-Cañadas JM, Carbajosa Dalmau J, et al. High-flow therapy via nasal cannula in acute heart failure. Rev Esp Cardiol. 2011;64:723–5.
  16. Millar J, Lutton S, O’Connor P. The use of high-flow nasal oxygen therapy in the management of hypercarbic respiratory failure. Ther Adv Respir Dis.2014;8(2):63–4.
  17. McGinley BM, Patil SP, Kirkness JP, Smith PL, Schwartz AR, Schneider H. A nasal cannula can be used to treat obstructive sleep apnea. Am J Respir Crit Care Med. 2007;176:194–200.
  18. Baillard C, Fosse JP, Sebbane M. Noninvasive ventilation improves preoxygenation before intubation of hypoxic patients. Am J Respir Crit Care Med. 2006;174:1710177.
  19. Miguel-Montanes R, Hajage D, Messika J, Bertrand F, Gaudry S, Rafat C, et al. Use of high-flow nasal cannula oxygen therapy to prevent desaturation during tracheal intubation of intensive care patients with mild-to-moderate hypoxemia. Crit Care Med. 2015;43:574–83.
  20. Marcel Simon, Stephan Braune, Daniel Frings, Ann-Kathrin Wiontzek, Hans Klose and Stefan Klugel. High-flow nasal cannula oxygen versus non-invasive ventilation in patients with acute hypoxaemic respiratory failure undergoing flexible bronchoscopy - a prospective randomised trial Critical Care. 2014;18:712
  21. Rello J, Pérez M, Roca O, Poulakou G, Souto J, Laborda C, et al. High-flow nasal therapy in adults with severe acute respiratory infection. A cohort study in patients with 2009 influenza A/H1N1v. J Crit Care. 2012;27:434–9.
  22. Messika J, Ahmed KB, Gaudry S, Miguel-Montanes R, Rafat C, Sztrymf B, et al.Use of high-flow nasal cannula oxygen therapy in subjects with ARDS: a 1-year observational study. Respir Care. 2015;60:162–9.
  23. Nuttapol Rittayamai MD, Jamsak Tscheikuna MD, Nattakarn Praphruetkit MD, and Sunthorn Kijpinyochai MD.Use of High-Flow Nasal Cannula for Acute Dyspnea and Hypoxemia in the Emergency Department. Respiratory care. 2015; vol 60 no 10.
  24. Lenglet H, Sztrymf B, Leroy C, Brun P, Dreyfuss D, Ricard JD. Humidified high flow nasal oxygen during respiratory failure in the emergency department: feasibility and efficacy. Respir Care. 2012; 57(11):1873-8.
  25. Huiying Zhao1, Huixia Wang, Feng Sun, Shan Lyu and Youzhong An. High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy but not to noninvasive mechanical ventilation on intubation rate: a systematic review and meta-analysis. Critical Care. 2017; 21:184.
  26. Corley A, Rickard CM, Aitken LM, Johnston A, Barnett A, Fraser JF, Lewis SR, Smith AF. High-flow nasal cannulae for respiratory support in adult intensive care patients (Review). Cochrane Database of Systematic Reviews. 2017.
  27. Frat JP, Thille AW, Mercat A, Girault C, Ragot S, Perbet S, et al. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med. 2015;372:2185–96.
  28. Stephan F, Barrucand B, Petit P, Rézaiguia-Delclaux S, Médard A, Delannoy B, et al. High-flow nasal oxygen vs noninvasive positive airway pressure in hypoxemic patients after cardiothoracic surgery: a randomized clinical trial. JAMA. 2015;313:2331–9.
  29. Hernandez G, Vaquero C, Colinas L, Cuena R, Gonzalez P, Canabal A, et al. Effect of postextubation high-flow nasal cannula vs noninvasive ventilation
    on reintubation and postextubation respiratory failure in high-risk patients: a randomized clinical trial. JAMA. 2016;316:1565–74.
  30. Oriol Roca; Marina García-de-Acilu; Jean-Damien Ricard. High-Flow Nasal Cannula Meta-Analysis: Do Not Mix Apples and Oranges! Critical Care Medicine. 2017; 45(2):e244.
  31. Bram Rochwerg , Laurent Brochard, Mark W. Elliott, Dean Hess, Nicholas S. Hill, Stefano Nava and Paolo Navalesi, Massimo Antonelli, Jan Brozek, Giorgio Conti, Miquel Ferrer, Kalpalatha Guntupalli, Samir Jaber, Sean Keenan, Jordi Mancebo, Sangeeta Mehta and Suhail Raoof. Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure. Eur Respir J. 2017; 50: 1602426.


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