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

Outline Introduction Oxygen Delivery Devices Optimization of Oxygenation 2

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

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

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

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

Oxygen Therapy Devices 2 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

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

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

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

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

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

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

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

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

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

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

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

Self Inflating Manual Resuscitator 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 19

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

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

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

Optimization of Oxygen Therapy 23

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

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

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

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

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

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

Optimization cont. Check my source! Is the flow set high enough? 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. 30

Optimization cont. Reposition patient. Listen to chest. 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? 31

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

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

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

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

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

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