breathing problems at school: pulse oximetry, asthma, and the return to control harold j. farber,...

Breathing problems at school:Pulse Oximetry,

Asthma,and the Return to Control

Harold J. Farber, MD, MSPH

Associate ProfessorBaylor College of Medicine

Section of Pediatric Pulmonology

Associate Medical Director for Chronic Conditions

Texas Children’s Health Plan

hjfarber@texaschildrens.org

How to assess severity breathing problems:

It is more than the It is more than the Oxygen SaturationOxygen Saturation

A child can have severe difficulty breathing but a normal oxygen saturation!

Severe Respiratory Distress:

Symptoms– Anxiety– Agitation– Persistent cough– Trouble speaking more

than a word or two– Grunting

Signs– Tachypnea– Retractions– Wheezing – Stridor– Flaring– Use of accessory

muscles

– Lack of wheezing.

Pulse Oximeters

Oxygen Saturation

Measuring the Oxygen Saturation

Pulse oximetry depends on the

pulse.– If you don’t have

a good pulse wave you have

garbage

Oxygen Saturation Error:

Pulse oximeters only calibrated from 75% to 100% saturation (unethical to take healthy adult to <75% SpO2)

May be inaccurate under 75% SpO2

Sources of error:– Ambient light– Motion Artifact– Nail Polish– Carbon monoxide

– Hypoperfusion Shock Cold finger

Oxygen Saturation:Oxyhemoglobin Dissociation

Curve

97.50%90%

75%

50%35%

13.50%0%

20%

40%

60%

80%

100%

120%

0 50 100 150

PaO2

Oxy

hem

oglo

bin

Sat

urat

ion

SpO2

With PaO2 above 60, SpO2 is > 90%. Oxygen content does not change much

When PaO2 drops <60, SpO2 rapidly decreases. Oxygen content of the blood rapidly decreases.

Processes Leading to Desaturation V-Q mismatch

– Example: Asthma Bronchiolitis Atelectasis Pneumonia

– Treatment: Supplemental O2

Hypoventilation– Examples

Guillaine Barre Syndrome Botulism Neuromuscular diseases

– Treatment: Supplemental

VENTILATION!

Tracheal Obstruction– Severe Croup– Aspirated foreign body–Tracheostomy plug–Treatment:

Open the airway

Peak Flow Meters

Provides a number that measures how hard the child blows out.

Peak expiratory flow is effected by– Effort– Lung size / child size– How open or closed breathing tubes are

How to interpret peak flow readings

Is it a maximal effort using correct technique, or is it garbage?

If maneuver is done correctly with maximal effort interpret in relation to personal best or predicted based on age, ethnicity, and height.

How to interpret peak flow readings

Peak flow over 80% of predicted or personal best: Green zone. All is well

Peak flow 50-80% of predicted or personal best: Yellow zone. Mild asthma flare.

Peak flow below 50% of predicted or personal best: Red zone: Urgent medical attention is needed.

Assessing Asthma Severity

Recognizing Symptoms

Recognizing Symptoms

Recognizing Symptoms

Recognizing Symptoms

Handling an asthma flare at school

Anything I tell you takes a back seat to school policy.

Handling an asthma flare at school

First: Do not leave child alone Second: Assess severity – is it mild,

moderate or severe? Third: Look at the child’s asthma plan – If

appropriate consider giving a quick relief medicine– Albuterol (Ventolin, Proventil, ProAir)– Levalbuterol (Xopenex)

If severe asthma flare

Breathing fast Hardly able to speak a few words between

breaths Nasal flaring Retractions

If severe asthma flare

Breathing fast Hardly able to speak a few words between breaths Nasal flaring Retractions

Give quick relief medicine (if available)Call 911Notify parentsAllow to rest in position of comfortDo NOT leave child alone

Preventing the flare ups:

Asthma is not controlled if:– If frequent asthma symptoms at school– If severe asthma flares needing urgent

treatment at school– If asthma interferes with exercise– If asthma interferes with sleep.

Preventing the flare ups:

If asthma is not controlled: Communicate with child’s parents and health care providers.

Advocate for the child. Asthma can be controlled.

When asthma is well controlled There are no asthma symptoms. No cough. No

wheeze. No chest tightness. Need for quick relief medication for asthma

symptoms is less than twice a week. A child’s sports participation is not limited by

his/her asthma.– Sometimes quick relief medicine is needed before

exercise

There are NO asthma attacks: daytime or nighttime.

There are no Emergency Room visits for asthma

Asthma Control:

Reduce Impairment– No chronic or troublesome symptoms– Day to day activities are not limited by asthma– Normal or near normal lung function

Reduce Risk– Prevent flare ups/ED

visits/hospitalizations/death– Prevent progressive loss of lung function– Minimize medication side effects.

3 Lines of Defense

Manage the Environment– Reduce triggers

Manage the Breathing Tubes– Medication to make airways less sensitive

Manage the Flare ups– Recognize attacks early and head them off at

the pass

Types of asthma triggers

Irritants– Smoke– Air pollution– Strong Chemicals– Air “fresheners

Allergens– Furry or feathered animals– Dust and mold– Pollens

Reducing Asthma Triggers at School (see EPA IAQ Tools for Schools)

– No air fresheners or sprays in classroom– No furry or feathered animals in classroom– No smoking in or around school– Building maintenance – to reduce dust and

mold problems. – Use integrated pest management to reduce

chemicals– Don’t cut grass, etc. when children are present– Don’t idle motor vehicles (cars, buses, etc.)

near school, when children are waiting.

Smoke and asthma

When a child is smoke exposed– Asthma medications don’t work as well – Viral infections are more severe

Parents are the most important source of a child’s smoke exposure

FREE help is available– National Cancer Institute/American Cancer

Society QUITLINE: 1 800 QUIT NOW

Graphic from Farber HJ, Boyette M. Control Your Child’s Asthma: A Breakthrough Program for the Treatment and Management of Childhood Asthma. Owl Books, 2001. Used with Permission.

Guide to asthma medicines

Quick Relivers– Short Acting Beta Agonists

Albuterol (inhaled)– Impairment:

Symptom relief within minutes, lasts about 4 hours Useful to prevent exercise induced asthma

– Risk: Overuse associated with increased risk

hospitalization, ED visit, mortality Warning: Be stingy with SABA refills!

Guide to asthma medicines

Long Acting Beta Agonists– Salmeterol: Onset in ½ hour, lasts about 12 hrs– Formoterol: Onset in minutes, lasts about 12 hrs

IMPAIRMENT: – When used with an inhaled corticosteroid day to day asthma

control is improved. RISK:

– When used without an inhaled corticosteroid, risk of hospitalization, ED visit, mortality is increased.

– LABA + ICS combo reduces impairment, has minimal impact on risk.

Guide to asthma medicines

Inhaled corticosteroids– Regular use:

Impairment:– Reduces asthma symptoms– Onset 1-2 weeks, max effect ~ 4-6 weeks

Risk: – Reduces risk of flare ups– Reduces risk for hospitalization/ED visit/mortality– Most of benefit achieved at low to moderate doses– Adherence to regular use is major challenge.

Guide to asthma medicines

Leukotriene modifiers– Impairment:

Equivalent to low dose ICS

– Risk: Inferior to low dose ICS

– Gives additional symptom reduction when combined with low to moderate dose ICS.

– Possible benefit in Viral triggered asthma Smoke triggered asthma

Guide to asthma medicines

Oral corticosteroids (Prednisone, Prednisolone)– Speeds resolution and attenuates severity of

moderate to severe asthma flare up– Steroid toxicity minimized by occasional use

and short bursts– Poorly controlled moderate to severe asthma

may need longer steroid taper to reverse long-standing airways inflammation

Teaching Role of Medication

Teaching Role of Medication

Albuterol/ Xopenex

Teaching Role of Medication

Albuterol/ Xopenex

Inhaled corticosteroid

Teaching Role of Medication

Albuterol/ Xopenex

Prednisone/ Prednisolone

Teaching Role of Medication

Albuterol/ Xopenex

Prednisone/ Prednisolone

Teaching Role of Medication

Albuterol/ Xopenex

Prednisone/ Prednisolone

Inhaled corticosteroid

Asthma Action Plans are Important!

In summary

Appropriately assess severity of an asthma flare.– If in doubt, believe the child

Asthma flares can be prevented by good asthma control

Written asthma action plans are essential If a child’s asthma is not in control

– Talk to their parents, physician, or care manager

– Texas Children’s Health Plan care management (if child is TCHP member):

832 828 1430

Asthma Research at TCH

Gene-Environments and Admixture in Latino Asthmatics (GALA-2) study– NIH funded multi-center case-control study– Objective: Determine genetic factors and gene-

environment interactions associate with asthma in Latinos

GALA-2 Study Eligibility:

– Age 8-21 years– Latino parents and grandparents– CASES:

Has physician diagnosed asthma Has been symptomatic within past 2 years

– CONTROLS Does not have asthma or allergies

GALA-2 Study

Study Procedures– All subjects:

FREE Allergy skin testing for common inhalant allergens

FREE Lung function testingQuestionnaireBlood Draw

GALA-2 Study

Locations– Texas Children’s Hospital– Ben Taub General Hospital

Compensation– $40 per visit completed– Parking Validation– Small gift provided for children

All study materials and personnel are bilingual (English/Spanish)

GALA-2 Study

Call 832 – 822 – GALA

(832 822 4252)

for information or to enroll

Summary

GALA– 8-21 years– Latino Ancestry– Asthma cases and healthy controls– Free allergy skin testing and lung function testing– To refer:

Call 832 822 GALA We can send you recruitment flyers.

– $40 per visit compensation for patients