Dr Duncan Powrie Consultant Chest Physician Southend University Hospital December 2018 2 Simple spirometry FEV 1 Forced Expiratory Volume in 1 second how much you can blow out in the first second of a forced blow ID: 935789
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Slide1
Restrictive lung disease
Dr Duncan
Powrie
Consultant Chest Physician
Southend
University Hospital
December
2018
Slide22
Simple spirometry
FEV
1
= Forced Expiratory Volume in 1 second
(
how much you can blow out in the first second of a forced blow
)
FVC = Forced Vital Capacity
(
how much you can breathe out altogether in a forced blow)
VC = Vital Capacity (
how much you can sigh out altogether in a full, steady blow)
FEV
1
/FVC ratio
= a calculation using the above measurements
(% of total that can be forced out in the first second
)
Slide33
Performing spirometry
1
Record the patient’s sex age and height to find their predicted normal values
Ask the patient to:
breathe in as deeply as possible
blow out forcibly as hard and fast as possible until there is nothing left to expel
*Repeat the procedure twiceThis should give 3 readings, with at least 2 within 100ml or 5% of each other
* severe patients may take up to 15 seconds
Consistent result Inconsistent result
Slide4Slide55
Obstructive vs.restrictive patterns
If the ratio FEV
1
/FVC <70%, obstruction is present
If this ratio is normal but FEV
1
and FVC are both reduced, restrictive pattern is presentA restrictive pattern should be referred to the doctor to check for lung fibrosis, pleural disease, chest wall disease. Obstructive disorder Restrictive disorder e.g COPD e.g. Fibrosing alveolitis, pleural diseaseFEV1
reduced (<80%) reduced (<80%)FVC normal or reduced reduced (<80%)FEV1/FVC ratio reduced (<70%) normal (>70%)
Slide6Assessment of a patient with restrictive
spirometry
Pulm
fibrosis (severe), neuromuscular disease, obesity , chest wall disease
History
Examination
CXR
Full PFTs (inc tests of resp muscle function)OximetryBlood gasesSleep study
Slide7Pulmonary fibrosis
Progressive exertional breathlessness
Dry cough
Arthralgia 20%
Weight loss
Finger clubbing in 50%
End inspiratory ‘velcro’ crackles
Cyanosis
Cor pulmonale
Slide8Slide9Slide10Slide11Epidemiology
6-28/ 100 000yr
M:F 1.7:1
Median age of diagnosis 70
Uncommon before 50
Slide12Risk factors
Exposure to metal or wood dust
Organic solvents
Mycotoxins
EBV, Hepatitis C
Cigarette smoking
Family history
Slide13Slide14Slide15Management
No really effective evidence based treatment
Information provision and supportive management is key
Monitor lung function if minimal symptoms
If deteriorating lung function consider triple therapy
Slide16Pirfenidone
Anti- inflammatory and anti-fibrotic action
Inhibits fibroblast proliferation
GI side effects
May reduce decline in lung function
Consider if FVC between 80 and 50% predicted
Slide17Breathlessness
Hypoxia is common as is desaturation on exercise
LTOT if pO
2
< 7.3 kPa or <8 if signs of pulmonary hypertension
Ambulatory oxygen if desaturates on exertion
Slide18Cough
Treat reflux
Consider simple linctus
Oral codeine
Consider oramorph or MST in end stage disease
Slide19Pulmonary rehabilitation
No randomised controlled studies
But strong evidence base in COPD
Improves QoL, reduces breathlessness
Deconditioning, breathlessness, nutritional deficit, fatigue and social isolation
Oxygen may be required to allow exercise
Slide20Other measures
Opioids
Anxiolytics
Relaxation and distraction techniques
Breathlessness clinic
Slide21Causes of acute deterioration
Reflux
Infection
Pneumothorax
pulmonary embolism
Slide22Lung transplantation
Patients <65
TLCO <40%
70-80% 1 year survival and 50% 5 yr survival
Slide23Prognosis
Variable
Median survival 2.5-3.5 years
Improved survival associated with young age, female sex, less honeycombing and better lung function at diagnosis
Death from respiratory failure or infection
Lung cancer common
Slide24Ventilatory pump failure
Myopathies- myotonic dystrophy
- muscular dystrophy
Neuropathy- MND
- bilateral diaphragm paralysis
- Guillain- Barr
é
NMJ abnormalities- myasthenia gravis
-anticholinesterase poisoningChest wall – obesity (often assoc obstructive sleep apnoea) - scoliosis - post thoracoplasty
Slide25Respiratory consequences of obesity
Obstructive sleep apnoea
Obesity hypoventilation syndrome
Acute hypercapnic respiratory failure
Postsurgical complications
Pulmonary hypertension
Slide26Mrs MC
54
♀
Asthma 38 years
No ITU admissions
Salbutamol prn only
Never smoked
Alcohol ½ bottle whisky dayObese 127kg
Slide27Admission
Presented with 4/7 SOB and wheeze
No cough
Given chlordiazepoxide, beclomethasone and atrovent inhalers by GP
No better so called ambulance
Slide28Examination
PEFR 150 (450) L/min
RR 22
Sats 95% on 2 L/min
P 130 regular
Diminished breath sounds throughout
No wheeze
Slide29ABG
pH 7.217
pCO
2
9.57
pO
2
10.23HCO3- 28.5BE -1.3
Slide30Admission bloods
Trop T 0.198
K
+
5.2
Urea 20.9
Creat 336
Hb 15.0WCC 14.3Neut 11.9Plt 255ALT 1230Bilirubin 39GGT 246Alb 38
ALP 130C. Ca2+ 2.02INR 1.7
Slide31Slide32Immediate treatment
Nebulised salbutamol and atrovent
Steroids
Pabrinex and vitamin B
Regular chlordiazepoxide stopped
BiPAP commenced
Slide33Respiratory review
Recent increase in alcohol consumption
Recent rapid weight gain
Daytime somnolence, falling asleep at work
Epworth score 14/24
Continue nocturnal BiPAP
Sleep study as inpatient
Slide34Sleep study
Low sats throughout- down to 70%
Multiple hypopnoeas
Some apnoeas
Lots of paradox
AHI- 29
Compatible with OSAHS
Slide35Discharge ABG
pH 7.417
pCO
2
5.61
pO
2
8.30HCO3- 26.3BE 1.5
Slide36Follow up
Weight loss 106.5kg
No alcohol since discharge
No daytime sleepiness
Epworth score 0/24
ABG continue to improve
BiPAP stopped
Slide37Severe obesity BMI > 30 kg/m
2
and
diurnal PaCO
2
> 45 mmHg (6 kPa)
In the absence of other known cause of hypoventilation
Olson et al
Am J Med 2005
Obesity hypoventilation syndrome
Definition
Slide38Morbid obesity
OSA
dyspnoea daytime hypersomnolence
Pèrez de Llano
Chest 2005
Obesity hypoventilation syndrome
Clinical presentation
Slide39PREVALENCE
Nowbar, Am J Med 2004
Mokhlesi B, CHEST 2007
Hospitalised patients
Stable state OSA
Increases
with
BMI;
Prevalence
>25%
for
BMI>40
kg/m
2
and
>50%
for
BMI>50
kg/m
2
15% in the
general
population of ambulatory obese patients?
Slide40Mechanisms underlying hypercapnia in obesity
Mokhlesi et al. Proc Am Thorac Soc 2008
Neurohormonal abnormalities
1
2
3
4
Slide41Berg Chest 2001
Mokhlesi Proceedings ATS 2008
Compared with obese control subjects, patients with OHS were statistically much more likely to have been diagnosed with:
Congestive heart failure (OR 9; 95% CI, 2.3–35)
Angina pectoris (OR, 9; 95% CI, 1.4–57.1)
Cor pulmonale (OR, 9; 95% CI, 1.4–57.1)
Obesity hypoventilation syndrome
High prevalence of associated cardiovascular morbidity in observational cohorts
Slide42Treatment
Weight loss
CPAP
BiPAP
Slide43Highly prevalent and easy to diagnose but underdiagnosed
Non invasive ventilation (NIV) improves blood gases, sleep, daytime sleepiness and mortality
Impact of NIV on cardiovascular morbidity?
Assessment and treatment of cardiovascular and metabolic risk recommended in OHS patients in association with NIV
Obesity hypoventilation syndrome
Take home message
Slide44Mr
CB
75 male
Raised PSA – normal bone scan, CT CAP unremarkable
General deterioration
Wgt loss, lethargy,
poor appetite
2 weeks dyspnoea – unable to sleep
Slide45No wheeze, no crackles
Sats 84% on air
Nil to find on examination
CXR small volume lungs
Slide46pH 7.24
pCO
2
13.41
pO
2
18.31
HCO3 42.5BE 9.8
Slide47Confused
Minimal history available
Dysarthric
Generally wasted
Poor respiratory effort
Thoraco-abdominal paradox
Multiple fasciculations
Slide48MND and respiratory failure
Respiratory failure in MND is common and a frequent cause of death
It may be the cause of presentation
Deterioration may be rapid
Multidisciplinary involvement is key
There is some evidence that NIV improves survival and quality of life
Slide49Slide50Mrs JT
45 female
Kyphoscoliosis from birth
Spinal fusion aged 14
Married
2 teenage chidren
Nil else in PMH
Slide514-6 week history of dyspnoea on exertion
1 week history of ankle oedema and new onset confusion
Started on salbutamol and frusemide by GP
Slide52Wheezy
JVP raised, oedema to knees
WCC 12 CRP 50
Na 115
pH 7.307 pCO
2
14.75
pO2 11.7 HCO3 54.1
Slide53Commenced on BiPAP
Deteriorating conscious level and worsening acidosis
Intubated
Echo- pulm hypertension, PAP 65mm Hg
Weaned to BiPAP
Slide544/52 post discharge
Using BiPAP all night 15:5
Exercise tolerance improved to half a mile
Oedema resolved
No daytime somnolence
pH 7.42 pCO
2
8.16 pO2 7.32 HCO3 38.4Commenced on LTOT IPAP increased 18
Slide552 years
Unlimited ET
BiPAP 24:5
pH 7.45 pCO
2
5.33 pO
2
9.77 HCO3 27.2Echo PAP 35mm Hg
Slide56Differential diagnosis of restrictive
spirometry
How to assess for respiratory muscle weakness
The importance of OHS