Oxygen Delivery Devices and Strategies for H1N1 Patients

1. Oxygen Delivery Devices and Strategies for H1N1 Patients Pandemic Planning Education Subcommittee October 2009 1

2. Outline • Introduction • Oxygen Delivery Devices • Optimization of Oxygenation 2

3. Introduction • Oxygen is a drug • Has a Drug Identification Number (DIN) • Colorless, odorless, tasteless gas • Makes up 21% of room air • Is NOT flammable but does support combustion. 3

4. Indications for Oxygen Therapy • Hypoxemia • Inadequate amount of oxygen in the blood • SPO2 < 90% • PaO2 < 60 mmHg • Excessive work of breathing • Excessive myocardial workload 4

5. What does hypoxemia look like? • Tachycardia • Agitation • Diaphoresis • Cyanosis • *Tachypnea* • Dyspnea • Accessory muscle use *Adult response – pediatric and neonatal patients experience bradycardia 5

6. Hazards of Oxygen Therapy • Absorption atelectasis • Likely with high FIO2 in presence of partial or complete small airway obstruction • Oxygen toxicity • Retinopathy of prematurity • Oxygen induced hypoventilation • Rare condition manifesting in some COPD patients with chronic high plasma bicarbonate 6

7. Oxygen Therapy Devices2 Types • Fixed • A device that meets all the patients inspiratory flow demands. • Designed to deliver a specific oxygen concentration to patient • Variable • Does not meet all inspiratory demands of the patient so some room air is breathed in • Oxygen concentration will vary with changes in the depth and rate of breathing • in general, the oxygen concentration is  by  the size of the reservoir 7

8. Fixed Device Cold Nebulizer • For adults set O2 flowmeter at maximum (flush) • 28-100% O2 selectable on collar - generally only reliable up to 50% • H1N1 standard requires dry bottle routed through Fisher Paykal humidifier • Rapid respiratory rate may decrease delivered FIO2 • Do not use for patient transport 8

9. Fixed Device High Flow Cold Nebulizer • Delivery at 60%, 65%, 75%, 85%, 96% selected by rotating collar • H1N1 standard requires dry bottle routed through Fisher Paykal humidifier • flowmeter must always be set to maximum!! • Do not use for patient transport 9

10. Fixed Device High Flow Cold Nebulizer mask with Tusks • Corrugated tubing added to aerosol mask exhalation ports to  reservoir volume and  oxygen concentration • Strategy to increase FIO2 in mask when patient hyperventilating AND SpO2 not maintained • Should be employed with High Flow Nebulizer 10

11. Face Tent • Use with a cold nebulizer • The “tent” portion is directed upwards • Uses: children and any patients who find mask claustrophobic or have had facial/nasal surgery • Not optimal for high FIO2 requirements 11

12. Tracheostomy Collar • Provides humidity & oxygen for tracheostomy patients via cold neb • adults - 10-15 LPM up to ‘flush’ • O2 adjusted on cold neb but maximum is usually 50% 12

13. Fixed Device Venturi Mask • Deliver a specific O2 concentration - 24%, 28%, 31%, 35%, 40%, 50% • Concentration adjusted by changing the Venturi jet • minimum required O2 flow rate is stamped on the base of each Venturi jet • O2 flow determines accuracy of FIO2 delivered • Usually used for COPD patients with demonstrated oxygen induced hypoventilation 13

14. Variable Flow Nasal Cannula • 22% - 40% • Stable is FIO2 based on: • Respiratory rate • O2 flowrate • Reservoir capacity of nasopharynx • adults  6 LPM • infants/toddlers  2 LPM • children  3 LPM • FIO2 is not affected by mouth breathing 14

15. Variable Device High Flow Nasal Cannula • Flow rates from 6-15 LPM • For patients that require > 6 LPM O2 but cannot tolerate a mask • Larger tubing inner diameter permits higher O2 flow • Tubing is always green 15

16. Variable Device Simple Oxygen Mask • Flow rate of 5-10 LPM • 35% -50% O2 • O2 flow and respiratory rate determine stability of delivered FIO2 • CAUTION Set flow rate must be > 5 LPM (adult and children) to flush exhaled carbon dioxide from mask 16

17. Variable Device Non-rebreathe Mask • Adults > 12 LPM • 60% - 90% depending on mask fit • CAUTION Always ensure reservoir bag remains partially inflated during inspiration 17

18. Variable Device Non-rebreathe Mask with Filter • CAUTION Always ensure reservoir bag remains partially inflated during inspiration Ensure bag does not deflate during inspiration • Valving system directs exhaled gas through bacterial filter • May be used for transport of H1N1 isolation patients • Must be assembled from stock Y’s, one way valves 18

19. Insert HME or bacterial filter between mask and bagger If mask is retained following use, clean with disinfecting wipe Cap the bagger when not in use Self Inflating Manual Resuscitator 19

20. Manual Ventilation • For Respiratory Arrest: • Deliver 1 breath every 5 to 6 seconds (10 to 12 breaths per minute). • For cardiac arrest deliver 2 breaths after every 30 compressions - deliver 8 to 10 breaths per minute without interrupting CPR once airway secured • Ensure that you have attached the EtCO2 sampling line to the correct port on the HME. The EtCO2 sampling port has ridges to screw on the sampling line male 20

21. Avoid hyperventilation which may result in: • Impaired hemoglobin function with reduced O2 delivery to tissues • Gastric distension • Increased intra­thoracic pressure causing: • decreased venous return to the heart and diminished cardiac output. • Increased intracranial pressure 21

22. Complications • Gastric distension is the most common adverse event in manual ventilation • Distension may impair lung expansion • Palpate the abdomen at commencement of bagging • Watch for visual distension and recheck palpation - request gastric tube placement if abdominal rigidity is noted 22

23. Optimization of Oxygen Therapy 23

24. Hypoxemia • Hypoxemia is defined as: • Low levels of oxygen in the blood • PaO2 of less than 60 mmHg (moderate) • SpO2 of less than 90% 24

25. Manifestations of Hypoxemia • Hypoxemia will affect vital signs by: • Increased heart rate • Increased blood pressure • Increased respiratory rate • CAUTION tachycardia is the adult response to hypoxemia – children and neonates will react to hypoxemia with bradycardia that may rapidly deteriorate to cardiac arrest • Hypoxemia in neonates and children requires rapid intervention and correction 25

26. Hypoxemia and H1N1 • Decompensation in hospitalized H1N1 Patients often begins with a decrease in SpO2 and increased oxygen demand • Be alert - and communicate even minor increases in oxygen flows or requirements for higher FIO2 devices 26

27. Causes of Hypoxemia • Shunt • Hypoventilation • As carbon dioxide increases oxygen falls • V/Q mismatching (ventilation/perfusion) serious complications of H1N1 produce V/Q mismatch • Pneumonia • Pulmonary edema • ARDS • Increased diffusion gradient • asbestosis • Early pulmonary edema 27

28. Oxygen Therapy • Goal of therapy is an SPO2 of >90% or for documented COPD patients 88–92% • As SPO2 normalizes the patients vital signs should improve” • Heart rate should return to normal for patient • Respiratory rate should decrease to normal for patient • Blood pressure should normalize for patient 28

29. Optimization • My SpO2 is < 90%, what next? • Is the pulse oximeter working/accurate • Do I have a good signal? • Heart rate plus/minus 5 bpm? • Is there adequate perfusion at the probe site? • Can the probe be repositioned? • Do other vital signs or clinical manifestations give evidence of hypoxemia? 29

30. Check my source! Ensure the O2 delivery device is attached to oxygen not medical air. Follow tubing back to source and ensure patency Are all connections tight? Is the flow set high enough? All nebs especially high flow large volume nebs need to be run at the highest rate. Turn flow meter to maximum for large volume nebs. Optimization cont. 30

31. Reposition patient. Avoid laying patient flat on back. Raise head of bed. Encourage deep breathing/coughing Listen to chest. Wheezing? Do they need a bronchodilator? Crackles? Encourage deep breathing/cough. Are they fluid overloaded? Optimization cont. 31

32. Can I improve the mechanics of breathing? Patient position Pursed lip breathing Abdominal breathing. Anxiety relief? Optimization cont. 32

33. Optimization cont. • Increase the flow: • With nasal prongs, increase the flow rate by 1 -2 lpm increments until target SpO2 is reached. • High flow nasal prongs can be maximally set at 15 lpm. • Call for physician assessment Medical if high oxygen flows are required. 33

34. Optimization cont. • What do I do if my patient is really hypoxemic (on low flow oxygen)? • Assess patient to determine cause of increasing oxygen requirements. • Best short term solution is non-rebreathe mask at 15 lpm. (reservoir stays inflated) • Goal saturation is still 88 – 92%. • Increase flow as required until re-assessed by physician 34

35. Optimization cont. • What do I do if my patient is really hypoxemic (on high flow oxygen)? • Assess patient to determine cause of increasing oxygen requirements. • Adjust FIO2 upwards in 10% increments titrating for target SPO2. • Call physician for further assessment 35

36. H1N1 points of emphasis • H1N1 decompensation requiring ICU admission usually begins with a systemic inflammatory response and pulmonary edema • CXR may not correlate with degree of oxygenation impairment • Gradually increasing oxygen requirement is a sentinel sign of impending respiratory failure 36

37. H1N1 points of emphasis • H1N1 Patients with escalating O2 needs warrant frequent monitoring for signs of impending respiratory failure • If a critical care triage system is operative, know the patient’s classification and prepare equipment accordingly – endotracheal intubation may not be an option 37