High flow nasal cannula (n dalmon)

An education lecture on the use of high flow nasal cannula oxygen therapy delivered to ITU nurses

1. Nick Dalmon Staff Nurse Intensive Care, William Harvey Hospital High Flow Nasal Cannula and Humidification

2. Risks Respiratory failure Preventing intubation Peri -intubation Post extubation therapy Questions What is HFNC Key Points Indications Contraindications Complications Positive effects Overview

3. •Oxygen and air source •Air-oxygen blender generates up to FiO2 1.0 at a flow rate of up to 60L/min •Active heated humidifier capable of providing 100% body humidity •Single limb heated inspiratory circuit (avoids heat loss and condensation) •Lightweight, flexible delivery tubing •Adjustable head strap •Soft and flexible nasal prongs •Different brands are available (e.g. Optiflow ™) High Flow Nasal Cannula ( Optiflow )

4. The amount of oxygen a patient gets depends on their inspiratory flow rate. Masks do not deliver consistent levels of Oxygen, HFNC does. Dead space is washed out ( Möller et al , 2015) Its not a reliable form of PEEP!! Mouth closed ~ 7cmH2O Mouth open ~ 2! (Ritchie et al , 2011) Key Points

5. Hypoxic respiratory failure, e.g.: •Community-acquired pneumonia •Viral pneumonia (e.g. influenza) •Acute asthma •Cardiogenic pulmonary odema •Pulmonary embolism •Interstitial pneumonia •Carbon monoxide poisoning Need for high FiO2 oxygen delivery in settings such as: •Intubation (pre-oxygenation and apnoeic oxygenation) •Post- extubation respiratory distress •Do-not-intubate/ palliative settings •Post-cardiac surgery •Oxygen supply during invasive procedures, e.g : TOE, upper GI endoscopy Indications

6. Epistaxis Base of skull fracture Surgery to the nose or upper aero-digestive tract Nasal obstruction; e.g. nasal fracture, tenacious secretions, tumour Contraindications

7. •Local trauma, discomfort and pressure areas •Epistaxis •Gastric distension •Blocked cannulae due to secretions Complications

8. High flow washes out carbon dioxide in anatomical dead space. I.e. the patient actually gets the oxygen you are giving them!! Because gas is generally warmed to 37°C and completely humidified, mucociliary functions remain good and little discomfort is reported. Compliance is increased as patients can talk, eat and drink whilst on HFNC Improved mouth care Less input from nursing staff!!! Positive effects

9. He is doing ok on that, lets not intubate…… In patients who are acutely unwell with high oxygen/flow rates, there should be a two hour limit on HFNC trial. It should NOT delay intubation. Failure of HFNC might cause delayed intubation and worse clinical outcomes in patients with respiratory failure (Kang et al , 2015) Risks

10. Gold standard for Type 2 is still BiPAP No big studies yet One small study compared treating patients in acute respiratory failure with facemasks and HFNC They found that the HFNC improved the patients PaO2 and was associated with a lower respiratory rate (Roca et al, 2013) Respiratory failure (Type 1)

11. A second study evaluated the efficiency, safety and outcome of high flow nasal cannula oxygen (HFNC) in ICU patients with acute respiratory failure. HFNC significantly reduced the respiratory rate, heart rate and increased pulse oxymetry . These improvements were observed as early as 15 min after the beginning of HFNC for respiratory rate and pulse oxymetry . PaO2 and PaO2/FiO2 increased significantly after 1 h HFNC in comparison with baseline ( Sztrymf et al, 2011). Respiratory failure continued

12. One study compared standard therapy, NIV and HFNC in patients with type 1 respiratory failure They found the intubation rate was lower in the HFNC group (38% of patients compared with 47% in the standard and 50% in the NIV group) but this was not statistically significant. It did show an improvement in ventilator free days and 90 day mortality (Frat et al, 2015). Preventing intubation

13. A study which looked at respiratory failure in do not intubate patients treated with HFNC first and escalated to NIV if HFNC failed The study showed that HFNC was effective in increasing oxygen saturations and lowered respiratory rate. 9 of the 50 (18%) patients recruited had to be escalated to NIV Preventing intubation

14. Preoxygenation and apnoeic oxygenation Compared to HFFM (high flow face mask), HFNC as a preoxygenation device did not reduce the lowest level of desaturation in an RCT ( Vour’ch et al , 2015 – PREOXYFLOW trial) Peri -intubation

15. A case series of 25 patients with difficult airways undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery had mean apnoea times of 14 minutes without desaturation (i.e. SaO2 >90%) ( Pateal et al, 2015; THRIVE study) Peri -intubation continued

16. Evidence is coming through that we should be extubating onto HFNC in all patients Compared to facemask, in low risk patients, at the same FiO2 as when ventilated, there were less episodes of desaturation (75% to 40%) and reintubation rates were reduced (21% to 4%). (Maggiore et al , 2014) Post extubation therapy

17. A second study compared high and low risk patients extubated onto “conventional oxygen therapy” and optiflow . Compared to the conventional therapy patients experienced lower rates of respiratory failure leading to reintubation ( 12% to 5%) (Hernández et al , 2016) Post extubation therapy continued

18. We all know how to clean an Optiflow , hopefully!! What about weaning? 2hours on 2 hours off…… Do you need a new set? When you do When you don’t…… Cleaning

19. A meta analysis published in late 2017 showed that HFNC is supreior to standard oxygen therapy in preventing intubation It also showed no diffrence in intubation rates between HFNC and NIV The recommend further RCT’s (Zhao et al, 2017) STOP THE PRESSES!!

20. What HFNC is What its good for What its not good for Should HFNC be our first line treatment for Type 1 RF? Good or bad for peri -intubation? Should we extubate onto HFNC routinely? Conclusion

21. Questions & Discussion

22. References Kang, B.J., Koh, Y., Lim, CM. et al. Intensive Care Med (2015) 41: 623. https://doi.org/10.1007/s00134-015-3693-5 Patel A, Nouraei SA. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia. 2015;70:(3)323-9. Vourc’h , M., Asfar , P., Volteau , C. et al. Intensive Care Med (2015) 41: 1538. https://doi.org/10.1007/s00134-015-3796-z Möller W, Celik G, Feng S, et al. Nasal high flow clears anatomical dead space in upper airway models. J Appl Physiol 2015;118(12):1525–1532. Ritchie JE, Williams AB, Gerard C, Hockey H. Evaluation of a humidified nasal high-flow oxygen system, using oxygraphy , capnography and measurement of upper airway pressures. Anaesth Intensive Care 2011;39(6):1103–1110. Maggiore SM, Idone FA, Vaschetto R, et al. Nasal high-flow versus Venturi mask oxygen therapy after extubation . Effects on oxygenation, comfort, and clinical outcome. Am J Respir Crit Care Med 2014;190(3):282–288. Hernández G, Vaquero C, González P, et al. Effect of Postextubation High-Flow Nasal Cannula vs Conventional Oxygen Therapy on Reintubation in Low-Risk Patients: A Randomized Clinical Trial. JAMA 2016;315(13):1354–1361.

23. Roca O, Pérez- Terán P, Masclans JR, et al. Patients with New York Heart Association class III heart failure may benefit with high flow nasal cannula supportive therapy: high flow nasal cannula in heart failure. J Crit Care 2013;28(5):741–746. Sztrymf B, Messika J, Bertrand F, et al. Beneficial effects of humidified high flow nasal oxygen in critical care patients: a prospective pilot study. Intensive Care Med 2011;37(11):1780–1786. Frat J-P, Thille AW, Mercat A, et al. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med 2015;372(23):2185–2196.