Transcript Medical certification fro respirator use

Medical fitness to wear
respirators
Allen Kraut, MD, FRCPC
Oct 3, 2010
OEMAC
Saskatoon, SK
Respirator program CSA Z94.9-02
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Roles and responsibilities
Hazard assessment
Selection of appropriate respirator
Health surveillance
Respirator fit testing
Training
Maintenance and storage
Program evaluation
Record keeping
Is the worker medically fit to use
a respirator?
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Detailed reports on respirator programs
but no guidance on medical decisions.
OSHA similar approach to CSA
What information is needed to
make a decision?
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Worker’s health status
Type of respirator
Type of work
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Physical level
Environments
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IDLH
Other protective equipment
What health information
influences decision?
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Physiologic conditions
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Pulmonary conditions
Cardiac conditions
Symptoms
Psychological issues
Safety issues
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Environment - Immediately toxic or oxygen deficient
atmospheres
Communication – Hearing, Vision
Loss of consciousness
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Seizure disorder, diabetic on insulin
Past ability to tolerate a respirator
What health information
influences decision?
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Seal issues
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Psychological -Claustrophobia
Respiratory - cough
Facial - deformities
? beard
Physiologic effects of a respirator
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-ve pressure air purifying
Pulmonary
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Increased resistance
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Increased tidal volume, decreased breathing
frequency, decreased alveolar ventilation
Submaximal workloads effects small
Maximal workloads may be decreased by
10%.
How does using a –ve pressure respirator
affect individuals with respiratory
disorders?
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Mild to moderate obstructive and
restrictive respiratory defects
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Subtle effects
Not sensitive or specific for determining
fitness to use a respirator
PFT abnormalities
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27 yo female geologist with cystic fibrosis
wishes to be hired by a mining company as a
field tester. She has worked for a contractor
doing similar work in the mine for the last
three years with according to her, no
problems. She reports using a half face mask
cartridge respirator regularly in the past with
no problems. Her FEV1 is 0.77 L 25%
predicted and FVC is 0.92 L 54% predicted,
the ratio of FEV1/FVC is 40%.
Is she fit to wear a half face mask cartridge
respirator?
PFT abnormalities
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1. Fit to wear the suggested respirator
2. Fit with restrictions/conditions
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3. Fitness decision needs to deferred
until additional information is available.
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What restrictions/conditions?
What information?
4. Unfit to wear the suggested
respirator.
Q1 PFTs
12
10
Fit
8
Restrictions/condit
ions
Deferred more info
6
4
Unfit
2
0
N =22
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Restrictions/conditions
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3 could do tasks
1 air powered, fresh air supply
Deferred
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1 check pfts to follow decline
2 speak to respirologist
3 more info on job and person
1 blood gas, diffusion
2 trial of respirator
2 get out in emergency
My answer #3
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1. Verified that she could wear her
respirator and do her work
2. Verified her sickness absences
3. Verified that she could exit the mine.
Q1 PFTs
16
14
Fit
12
10
Restrictions/condit
ions
Deferred more info
8
6
Unfit
4
2
0
N =23
After verification #2
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Restrictions/conditions
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1. Only fit for current job
2. Needed to report any significant change
in medical condition
3. Needs to provide a letter yearly from her
physician stating that her condition has not
deteriorated
What PFT measurement gives the best
overall assessment of lung function?
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FEV1 > 60% predicted - trial of
respirator
Lower levels for light duties
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ATS guidelines
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Am J Respir Crit Care Med 1996 154:1153-1165
How often do PFTs help in the
certification decision?
5,569 workers DOE facility
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98.7% no restriction
71 (1.3%) restrictions
5 (0.1%) solely on basis of PFTs
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Pappas et al AJIM, 1999;35:390-94
Can questionnaires screen out people who do
not need further assessment?
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YES
49/413 abnormal PFTs only 1 case did it influence
decision
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Pappas et al, AJIM 1999;35:395-400
Pregnancy
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27 yo Female 16 week pregnant works in a
aircraft manufacturing facility. A variety of
solvent based compounds are used and air
measurements for all of them are < 2% of
the TLV. Cartridge respirators are optional in
this workplace. Alternative work is not
available and she wishes to wear a cartridge
respirator for about two hours a day when
she feels her exposures would be greatest. Is
she fit to wear a negative pressure
respirator?
Pregnancy
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1. Fit to wear the suggested respirator
2. Fit with restrictions/conditions
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3. Fitness decision needs to deferred
until additional information is available.
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What restrictions/conditions?
What information?
4. Unfit to wear the suggested
respirator.
Q2 Pregnancy
14
12
Fit
10
6
Restrictions/condit
ions
Deferred more info
4
Unfit
8
2
0
N =22
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Restrictions/conditions
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2 concerned about solvents
1 fit tested can change in pregnancy
1 personal monitoring and monthly assessment of fitness
Deferred
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1 assess workload
2 more medical info past pregnancies
1 list exposures
1 pft
1 fit may change during pregnancy
1 concerned re solvents
Q2 Pregnancy
18
16
Fit
14
12
Restrictions/condit
ions
Deferred more info
10
8
6
Unfit
4
2
0
N =22
My answer #1
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Issues
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1. Does pregnancy affect the ability to
wear a respirator?
2. Is the pregnant worker at risk if the
respirator fails?
Does pregnancy affect the
ability to wear a respirator?
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Israeli study – Gulf War
48 pregnant women wearing gas masks
24 during labour and delivery.
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No decrease in maternal po2
Mild tachypnea
No fetal heart rate abnormalities.
Delivered babies did well Apgar > 8 at 1’
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Can J. Anaesthesia 1992;39:895-96.
Seizure disorder
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28 yo male with a history of head trauma and residual seizure
disorder wishes to work in maintenance at a food processing
plant. He has no other neurologic sequelae from his injury and
is otherwise well. His work involves intermittently using a
negative pressure cartridge respirator when exposed to irritants
and six times per year using an SCBA to clean the inside of
large vats. This is quite hard work. He supplies a note from his
physician stating that he is compliant with his medication and
that his drug levels are in the therapeutic range. His last seizure
was 6 months prior when he was up all night due to travel
arrangement complications during a trip. His last seizure prior to
that was 18 months previous. He has had an aura prior to
previous seizures.
Is he fit to wear the respirators required for his job?
Seizure
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1. Fit to wear the suggested respirators
2. Fit with restrictions/conditions
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3. Fitness decision needs to deferred
until additional information is available.
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What restrictions/conditions?
What information?
4. Unfit to wear the suggested
respirators.
Q3 Seizure
12
10
Fit
8
Restrictions/condit
ions
Deferred more info
6
4
Unfit
2
0
N =22
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Restrictions/conditions
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2 Needs longer seizure free period 1 yr , 2 yr
4 No SCBA
4 Can’t work alone
Deferred
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1 consult neurologist
1 CV fitness, can’t work alone
1 Is this a unionized environment? If so he will have to be
approved as an arbitrator would declare him to be fit if
tested at a hearing as it would be. The cost of an arbitration
is usually $15,000, so to save the waste of that money he
would be approved without further ado.
1 can he drive?
Q2 Seizure Issue SCBA
12
10
Fit
8
Restrictions/condit
ions
Deferred more info
6
4
Unfit
2
0
N =22
Seizure free periods- after
diagnosis of epilepsy
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Private driver - 6 –12 months seizure
free compliant patient on medication
Commercial driver- five years
NFPA 5 years seizure free
Safety sensitive jobs in railway – 5
years
Seizure My answer #1
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Frequency of seizures
Compliance with treatment
Precipitating circumstances
Presence of warning symptoms
Asthma
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45 YO Male egg processing manager develops
occupational asthma secondary to exposure to egg
proteins. At diagnosis he presented to ER. With
appropriate treatment he is feeling well and has had
no further hospital visits. Pre-bronchodilator
spirometry shows mild obstruction which resolves
with salbutamol. The man does not want to change
careers because he feels he will not be able to
replace his income. He is able to limit, but not
eliminate his exposure to the egg proteins at work.
Should be allowed to work wearing a negative
pressure respirator while exposed to eggs?
Asthma
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1. Fit to wear the suggested respirator
2. Fit with restrictions/conditions
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3. Fitness decision needs to deferred
until additional information is available.
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What restrictions/conditions?
What information?
4. Unfit to wear the suggested
respirator.
Q3 Asthma
10
9
8
7
6
5
4
3
2
1
Fit
Restrictions/condit
ions
Deferred more info
Unfit
0
N =22
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Restrictions/conditions
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4 medical follow up, spirometry, methacholine challenge,
symptoms
1 fit testing
3 concerned about exposure if sensitized should not be
exposed
Deferred
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1 on the job evaluation
1 pre post pfts
1review history no anaphylactic reactions
1 Need spirometry would follow post exposure
1 how long since diagnosis, PAPR
Q2 Asthma
14
12
Fit
10
6
Restrictions/condit
ions
Deferred more info
4
Unfit
8
2
0
N =22
Occupational immunologic
asthma
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Ideally stop exposure
Stopping exposure may be associated
with loss of income
? PPE
Asthma –irritant or non
occupational
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Protects against exposure
Harber (JOEM 2010)Asthmatics may
report more symptoms with cartridge
respirators.
If the respirator is not used properly
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increased exposure to irritants
? Asthmatic attack.
Asthma #2
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Conditions –Needs medical follow up q
6 months for lung function testing and
methacholine challenge while working
with potential exposure.
Continued working for 15 years, no
persistent decline in PFTs.
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Laid off, could not find permanent work.
SCBA
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45 yo male with history of Type II diabetes
on metformin, obesity (BMI 32), mild
hypertension, smoking ½ ppd, normal
cholesterol is referred for respirator
certification. He works in a chemical plant
and he needs to wear an SCBA for emergency
circumstances in case there is a spill and he
has to rescue a co-worker. He has no history
of cardiac disease or symptoms suggestive of
angina. His father had an MI at age 67. Is he
fit to wear an SCBA respirator?
Cardiac risk factors.
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1. Fit to wear the suggested respirator
2. Fit with restrictions/conditions
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3. Fitness decision needs to deferred
until additional information is available.
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What restrictions?
What information?
4. Unfit to wear the suggested
respirator.
Q3 Cardiac Risk
12
10
Fit
8
Restrictions/condit
ions
Deferred more info
6
4
Unfit
2
0
N =22
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Restrictions/conditions
Deferred
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1 practical test
8 cardiac stress
2 more medical info
3 pfts
1 no facial hair
Q3 Cardiac Risk
12
10
Fit
8
Restrictions/condit
ions
Deferred more info
6
4
Unfit
2
0
N =22
SCBA cardiac risk factors
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Although likelihood of needing SCBA is
low, needs to be able to use it.
Need further information
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Exercise test
If negative then ok.
How should respirator
certification decision be made?
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No clear guidelines
Tolerance more dependent on comfort and
psychological factors than physiologic
measures
In general, if a worker is healthy enough to
do the job without a –ve pressure respirator
he/she should be able to perform the work
with a respirator.
Past experience best guide.
How should a decision be made?
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Estimate the likelihood of an
unacceptable adverse outcome.
If no clear contraindications,
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trial and observe
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at work or
in simulated situation
If a worker reports difficulties try a
different type of respirator
Conclusions
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The vast majority of people who can
work, can tolerate a –ve pressure air
purifying resp.
Issue is usually fitness to work not
fitness to wear respirator
Questionnaires can be used to screen
people who require more intense
evaluation
Conclusions
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PFTs useful only in workers with
symptoms or history suggestive of lung
disease. May be needed for
surveillance purposes.
Worker’s should not be restricted from
using –ve pressure respirators solely
based on spirometry results.
Conclusions
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IDLH environments, emergency workers,
SCBA users require more intense evaluation
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Cardiac
Pulmonary
Musculoskeletal
Seal issues
Post certification follow up would be useful to
identify if worker having problems with a
respirator