Niv in covid-19

NIV in COVID-19 Pandemic

1. COVID-19 disease: NonInvasive Ventilation

2. M ain finding was that the vast majority of Covid-19 patients treated by CPAP recovered from moderate-to-severe AHRF

3. Italian Experience

4. When and for which patients?

5. HFNC vs NC

6. COVID-19 & NIV Early series suggested high mortality for patients with COVID-19–associated respiratory failure who received invasive mechanical ventilatory support

7. Current thinking suggests that NIV may be an appropriate bridging adjunct in the early part of the disease progress and may prevent the need for intubation or invasive ventilation

8. Published cohorts suggest that noninvasive ventilation is a commonly used intervention in COVID-19-related AHRF It is uncertain whether noninvasive ventilation is beneficial or harmful for patients with COVID-19

9. A total of 586 confirmed COVID-19-positive patients were hospitalised during the study period, of whom 103 (17.6%) required noninvasive ventilation or invasive mechanical ventilation Among those patients who had an initial trial of noninvasive ventilation, 27/ 58 progressed to invasive mechanical ventilation whereas 31/58 did not require subsequent invasive mechanical ventilation

10. Of note, 29/31 (94%) patients in Group NIV alone were discharged from hospital alive with the remaining 2/31 (6%) being alive in the ICU at the time of data collection

11. Network Metaanalysis : Ferreyro BL et.al.JAMA . Published online June 4, 2020 Association of helmet NIV with reduced rate of intubation and reduced mortality

12. Continuous Positive Airway Pressure (CPAP), a form of NIV, appeared to have a more significant and positive role than initially thought

13. For some patients, while NIV may temporarily improve oxygenation and work of breathing, it does not change natural disease progression and is not a replacement for intubation and invasive ventilation

14. General Considerations The key to the successful application of noninvasive ventilation is in recognizing its capabilities and limitations Identification of the appropriate patient for the application of noninvasive ventilation (NIV ). It may involve a trial of noninvasive ventilation.

15. Patient Selection

16. Patient inclusion criteria  Patient cooperation (an essential component that excludes agitated, belligerent, or comatose patients) Dyspnea (moderate to severe, but short of respiratory failure) Tachypnea (>24 breaths/min) Increased work of breathing (accessory muscle use, pursed-lips breathing) Hypercapnic   respiratory acidosis  (pH range 7.10-7.35) Hypoxemia (PaO 2 /FIO 2 < 200 mm Hg, best in rapidly reversible causes of hypoxemia)

17. Absolute contraindications Coma Cardiac arrest Respiratory arrest Any condition requiring immediate intubation

18. Other Contraindications Cardiac instability GI bleeding - Intractable emesis and/or uncontrollable bleeding Inability to protect airway Potential for upper airway obstruction

19. Interface Vented Mask Non-Vented Mask

20. Full Face Nasal Mask

21. Oronasal Mask Helmet

22. NIV Ventilators Critical care Ventilators Specialty NIV Ventilators

23. Mode of Ventilation Past experience In part on the capability of ventilators available to provide support In part on the condition being treated.

24. Mode of Ventilation The primary NIV mode is the continuous positive airway pressure (CPAP), the pressure is initially set at 10 cm H2O and then adjusted according to SpO2 and clinical tolerance Pressure support ventilation (PSV) should be considered over CPAP in patients who showed respiratory acidosis (pH < 7.35), tachypnea >30/min or a vigorous activity of respiratory accessory muscles

25. Boussignac positive pressure valve

26. UCL Ventuar CPAP device

27. UCL Ventura CPAP Device

28. In severe COVID-19, initial CPAP settings have been suggested 10 cmH2O and 60% oxygen

29. Initial IPAP/EPAP settings Start at 10 cm water/5 cm water Pressures less than 8 cm water/4 cm water not advised as this may be inadequate Initial adjustments to achieve tidal volume of 5-7 mL/kg (IPAP and/or EPAP)

30. Subsequent adjustments  Increase IPAP by 2 cm water if persistent hypercapnia Increase IPAP and EPAP by 2 cm water if persistent hypoxemia Maximal IPAP limited to 20-25 cm water (avoids gastric distension, improves patient comfort) Maximal EPAP limited to 10-15 cm water

31. NIV Failure A mean VTE higher than 9.5mL/kg over the first four cumulative hours of NIV accurately predicted NIV failure

32. Be careful that NIV may unduly delay intubation in non-expert hands We insist on the notion that intubation should not be delayed

33. The expiratory limb of the circuit was equipped with an antimicrobial filter

34. Surgical Mask on HFNC

35. Periods off NIV should be of short duration, to prevent desaturation

36. Regular assessment of the patient’s pressure areas on the face must be taken, and protective dressings applied if necessary