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

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Oxygen Delivery Devices and Strategies for H1N1 Patients

Pandemic Planning Education Subcommittee October 2009

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Outline

Introduction

Oxygen Delivery Devices

Optimization of Oxygenation

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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.

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Indications for Oxygen Therapy

Hypoxemia– Inadequate amount of oxygen in the blood

– SPO2 < 90%

– PaO2 < 60 mmHg

Excessive work of breathingExcessive myocardial workload

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What does hypoxemia look like?

TachycardiaAgitationDiaphoresisCyanosis

*Tachypnea*DyspneaAccessory

muscle use

*Adult response – pediatric and neonatal patients experience bradycardia

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Hazards of Oxygen Therapy

Absorption atelectasis– Likely with high FIO2 in presence of partial or

complete small airway obstruction

Oxygen toxicityRetinopathy of prematurityOxygen induced hypoventilation

– Rare condition manifesting in some COPD patients with chronic high plasma bicarbonate

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Oxygen Therapy Devices2 Types

Fixed– A device that meets all the patients inspiratory flow

demands.– Designed to deliver a specific oxygen concentration to

patientVariable

– 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

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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

Fixed Device Cold Nebulizer

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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

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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

Fixed Device High Flow Cold Nebulizer mask with Tusks

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Face Tent

Use with a cold nebulizerThe “tent” portion is

directed upwardsUses: children and any

patients who find mask claustrophobic or have had facial/nasal surgery

Not optimal for high FIO2 requirements

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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%

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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

Fixed Device Venturi Mask

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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

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Flow rates from 6-15 LPMFor patients that require >

6 LPM O2 but cannot tolerate a mask

Larger tubing inner diameter permits higher O2 flow

Tubing is always green

Variable Device High Flow Nasal Cannula

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Flow rate of 5-10 LPM35% -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

Variable Device Simple Oxygen Mask

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Adults > 12 LPM60% - 90%

depending on mask fit

CAUTION Always ensure reservoir bag remains partially inflated during inspiration

Variable Device Non-rebreathe Mask

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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

Variable Device Non-rebreathe Mask with Filter

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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

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Manual VentilationFor 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

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Avoid hyperventilation which may result in:

– Impaired hemoglobin function with reduced O2 delivery to tissues

– Gastric distension– Increased intra thoracic pressure causing:

– decreased venous return to the heart and diminished cardiac output.

– Increased intracranial pressure

Complications

Gastric distension is the most common adverse event in manual ventilation

Distension may impair lung expansionPalpate the abdomen at commencement of

baggingWatch for visual distension and recheck

palpation - request gastric tube placement if abdominal rigidity is noted

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Optimization of Oxygen Therapy

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Hypoxemia

Hypoxemia is defined as:– Low levels of oxygen in the blood

PaO2 of less than 60 mmHg (moderate)

SpO2 of less than 90%

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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

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

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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

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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

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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?

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Optimization cont.

Check my source!– Ensure the O2 delivery Ensure the O2 delivery

device is attached to device is attached to oxygen not medical air.oxygen not medical air.

– Follow tubing back to Follow tubing back to source and ensure source and ensure patencypatency

– Are all connections tight?Are all connections tight?

Is the flow set high Is the flow set high enough?enough?– All nebs especially high All nebs especially high

flow large volume nebs flow large volume nebs need to be run at the need to be run at the highest rate.highest rate.

– Turn flow meter to Turn flow meter to maximum for large maximum for large volume nebs.volume nebs.

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Optimization cont.

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?

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Optimization cont.

Can I improve the mechanics of breathing?– Patient position

– Pursed lip breathing

– Abdominal breathing.

– Anxiety relief?

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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.

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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

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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

H1N1 points of emphasisH1N1 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

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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

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