Obstructive airways disease in old age

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Obstructive airways disease in old age

• Dr Stephen Allen
• The Royal Bournemouth Hospital

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Problems of diagnosis

• Patient perceptions
• Professional perceptions
• diagnostic grey areas
• degraded clinical information
• multiple pathology
• under use of spirometry
• cognitive/executive dysfunction

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Problems of treatment

• Patient expectations
• Professional expectations
• problems with inhalers
• problems with Steps 1 and 2
• uncertainty about Step 3
• cognition/praxis/executive function
• problems about self monitoring

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Spirometry in old age - myths
Most old people cant do a meaningful PEFR, FEV1
and FVC FALSE Almost all old people can do
spirometry if encouraged FALSE
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Spirometry in old age - facts
gt80 of 65-94 year olds can meet the ATS94
criteria performance is related to cognitive
scores, functional scores and educational
attainment not independently related to age,
BMI, or GDS the proportion of incompetent
patients rose with age, to about 40 at age 85 or
over Pezzoli et al Age Ageing(2003)3243-46 Belli
a et al Am J Respir Crit Care Med(2000)1611094-9
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Spirometry in old age - how?
screen for cognitive impairment (?
thresholds) High level of operator skill,
patience, enthusiasm use the ATS94 criteria
for quality control if ATS94 criteria not met,
consider using PEFR, Slow VC if in doubt, try
to do spirometry
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ATS94 criteria
3 curves acceptable, 2 of which reproducible
acceptable curve has - no artefact, an
acceptable start (back extrap. Vol lt5), FVC time
of 6s or more, final plateau 1s reproducible
curves have - difference of 200ml or less in FEV1
and FVC
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Alternatives to spirometry
respiratory impedance by forced oscillation
whole body plethysmography helium dilution
volumetry inspiratory impedance (ratio of
dP/dtmax to Vt/Ti) cross-sectional
radiography All these limited by complexity,
cost, unavailability or lack of data for elderly
patients
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Degraded clinical information
symptoms and signs of several pathologies
poor memory for symptoms reduced perception
thresholds -cough, airflow resistance, ?hypoxia
signs due to ageing effects of
cardio-respiratory deconditioning often present
with geriatric problems -confusion, falls,
incontinence, immobility, unable to
manage Connolly M. In Brocklehurst et al (eds)
Textbook of Geriatric Medicine and Gerontology,
5th edition, Churchill-Livingstone
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Inhaler therapy -problems in the frail elderly
cognition, memory, comprehension, executive
function praxis strength, dexterity,
co-ordination, sensory neuropathy vision
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Who is at risk?
LOW RISK - elderly patients who are well, compos
mentis and functioning independently - can do it
themselves LOW RISK - very frail, often overtly
demented, highly dependent on others - carers
take control of medication HIGH RISK - living
alone or with some support, cognitive/ executive
problems present but not yet severe, - still
expected to self-medicate Class 3 and 4
evidence
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A detailed look at the importance of higher brain
function for an adequate inhaler technique
A TALE OF FIVE STUDIES AND A PLAN
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Study 1
What determines whether an elderly patient can
use a metered dose inhaler correctly? Setting
outpatients, South Manchester Patients 30, mean
age 79.9, COPD or asthma, on MDI
therapy Assessment observation of MDI technique,
scored competent or not according to agreed
criteria Comparators age, source of
prescription, who taught the technique, length of
MDI treatment, AMTS
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Study 1 - contd
Findings 60 competent (only 10
perfect) Competence not related to age, duration
of treatment, gender, diagnosis, and weakly
related to hospital supervision Competence highly
related to AMTS, all competent patients had a
score of 7 or more (0/18 vs 7/12 P.0004) Allen
S C, Prior A. Br J Dis Chest(1986)8045-49
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Study 2
Competence thresholds for the use of inhalers in
people with dementia Setting inpatient
rehabilitation ward, Christchurch Patients 50,
mean age 81, inhaler-naïve, 5 groups - normal
(AMTS -10), borderline (7), mild dementia (6), 2
moderate dementia groups (5 and 4) Assessment 3
inhalers MDI (5 stage), MDI spacer (4 stage),
inspiration-triggered Aerolin Auto (3 stage).
Taught day 1 and tested day 2 in sequence
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Study 2 - contd
Findings percentage thresholds for competent
technique
0 50 100 5
stage 6
7 8 4 stage
5 6
8 3 stage
4 5
7 Allen SC Age Ageing(1997)2683-86
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Study 3
A comparison of the Turbohaler with a standard
metered dose inhaler in elderly subjects with
normal and impaired cognitive function Setting
rehabilitation inpatient ward Patients 30, mean
age 84, inhaler naïve, 3 groups - normal (AMTS
8-10), borderline (7), impaired (5 or 6)
Assessment 2 inhalers - MDI and Turbohaler,
taught in random order and tested next day for
competence
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Study 3 - contd
Results AMTS 8-10 AMTS 7
AMTSlt7 MDI 8/10
2/10 0/10 Turbo
10/10 9/10
3/10 P NS
lt0.05 NS Allen SC, Zaman S J
HK Ger Soc(2000)1075-77
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The message so far
adequate inhaler technique requires good
cognition patients with an AMTS of 8-10 can
usually learn inhaler use patients with an AMTS
of lt7 can rarely learn inhaler use some
patients with borderline/mildly impaired
cognition can learn to use operationally simpler
devices QUESTION why are some elderly patients
(20-30) with normal AMTS scores unable to learn
to use a MDI?
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Possible explanations
unrecognised global cognitive impairment
parietal lobe dysfunction with subtle impairment
of praxis frontal lobe dysfunction with
executive impairment
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Study 4
Ability to learn inhaler technique in relation to
cognitive scores and tests of praxis in old
age Setting inpatient rehabilitation
ward Subjects 30 inhaler-naïve patients, mean
age 85, AMTS 8-10 Method MDI training, analogue
score 0-10 (5/6 threshold for minimum
competence Separate observer performed MMTS, GDS,
Barthel ADL index, ideational dyspraxia test,
ideomotor dyspraxia test
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Study 4 - contd
Results Correlations r
P IS v MMTS 0.48
0.032 IS v IMD
0.45 0.039 IS v IDT
0.11 NS IS v Barthel
ADL 0.19 NS IS v GDS
- 0.23 NS
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Study 4 - contd
Results Thresholds
ISlt6 ISgt5
P MMTSlt23 9
0 MMTSgt22 3
18 lt0.01 IMDTlt14
7 1
IMDTgt13 5
17 lt0.01
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Study 4 - contd
Interpretation patients with impaired cognition
and/or problems with praxis are usually unable to
learn MDI technique However, some elderly
patients with normal AMTS, normal MMTS and no
apparent dyspraxia are unable to learn to use an
inhaler. Why? Could this be caused by impaired
frontal executive function? Allen SC, Ragab S
Postgrad Med J (2002)7837-39
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Study 5
Acquisition and short-term retention of inhaler
techniques require intact executive function in
elderly subjects Setting inpatient
rehabilitation ward Patients 30, inhaler-naïve,
mean age 85, AMTS 8-10 Methods Standard training
with MDI and Turbohaler in random order. Scored
by analogue scale (MDI) and competence (Turbo.)
on the same day (day 1) and next day (day
2). Separate measurements of MMSE and EXIT25
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Study 5 - contd
MDI score vs MMSE r
P Day 1
0.482 lt0.007 Day 2
0.540
lt0.002 MDI score vs EXIT25 Day 1
- 0.661
lt0.0001 Day 2
- 0.702 lt0.0001
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Study 5 - contd
MDI score lt6
MDI score gt5 P MMSE lt24
9 1
lt0.01 MMSE gt23
2 18 EXIT25 lt15
0 19
lt0.01 EXIT25 gt14
11 0
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Study 5 - contd
Turbo competent
Turbo incomp P MMSE gt23
21 3
lt0.01 MMSE lt24 0
6 EXIT25 lt15
21 0
lt0.01 EXIT25 gt14
0 9
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Study 5 - contd
EXIT25 gt MMSE gt AMTS in predicting ability to
acquire MDI and Turbohaler competence. Executive
brain function is the key element Allen SC et
al Age Ageing(2003)32299-302
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The plan
look at same factors for spirometry set up
functional brain imaging studies look at
flexing the thresholds with reinforcement etc
look at the predictive value of copying
intersecting pentagons
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Other evidence
Approx 70 of elderly patients unable to use
zanamivir (Relenza) dry powder inhaler Diggory P
et al BMJ(2001)322577-9