Transcript COPD - The Preoperative Association

Dr Gerard Meachery
The objectives of the
pre-anaesthetic assessment
• Evaluate the patient’s medical condition from medical history,
physical examination, investigations and, when appropriate, past
medical records
• Optimise the patient’s medical condition for anaesthesia and surgery
• Determine and minimise risk factors for anaesthesia
• Plan anaesthetic technique and peri-operative care
• Develop a rapport with the patient to reduce anxiety and facilitate
conduct of anaesthesia
• Inform and educate the patient about anaesthesia, peri-operative
care and pain management
• Obtain consent for anaesthesia
Guidelines on the radical management
of patients with lung cancer
• Lim E, Baldwin D, Beckles M, et al. Thorax 2010, 65
Suppl III, iii1-iii27
• A joint initiative by the British Thoracic Society and the
Society for Cardiothoracic Surgery in Great Britain and
Ireland undertaken to update the 2001 guidelines for the
selection and assessment of patients with lung cancer
who can potentially be managed by radical treatment
Guidelines on the radical management of
patients with lung cancer
• 2.1.3 Assessment of lung function
• 43. Offer surgical resection to patients with low risk of
postoperative dyspnoea. [C]
• 44. Offer surgical resection to patients at moderate to high risk
of postoperative dyspnoea if they are aware of and accept the
risks of dyspnoea and associated complications. [D]
• 47. Consider using shuttle walk testing as functional assessment
in patients with moderate to high risk of postoperative
dyspnoea using a distance walked of >400 m as a cut-off for
good function. [C]
• 48. Consider cardiopulmonary exercise testing to measure peak
oxygen consumption as functional assessment in patients with
moderate to high risk of postoperative dyspnoea using >15 ml/
kg/min as a cut-off for good function. [D]
Guidelines on the radical management of
patients with lung cancer
• 49. RR Further studies with specific outcomes are
required to define the role of exercise testing in the
selection of patients for surgery
• 51. Avoid taking pulmonary function and exercise tests
as sole surrogates for quality of life evaluation. [C]
Pulmonary Function Testing
Objectives
Categorise PFTs according to specific purposes
Identify at least one indication for spirometry,
lung volumes, and diffusing capacity
Obstructive and restrictive ventilatory defects
Relate respiratory history to indications for
performing pulmonary function tests
Pulmonary Function Testing
• Establish baseline lung function and evaluate the
presence or absence of lung disease
• Evaluate symptoms of dyspnoea
• Evaluate if the lung disease is primarily an obstructive,
restrictive or mixed ventilatory defect
• Quantify the respiratory impairment and monitor the
extent of known disease on lung function
• Monitor effects of therapies used to treat respiratory
disease
Pulmonary Function Testing
• Evaluate operative risk
• Perform surveillance for occupational-related lung
disease
• Evaluate disability or impairment
• Assess for reversible components to optimise a patient’s
clinical status
Spirometry
• Forced expiratory volume in 1 second (FEV1)
– Volume exhaled in the first second of an FVC
manoeuvre
– (forced exhalation from maximal inspiration)
• Vital capacity (VC)
– Total volume exhaled by a exhalation from maximal
inspiration
– Can be a forced exhalation (FVC) or a relaxed
exhalation (RVC) – best one taken as VC
• FEV1/VC
– Ratio between FEV1 and VC
Pulmonary Function Testing
• In normal spirometry, FVC, FEV1, and FEV1 -to-FVC
ratio are above the lower limit of normal
• The lower limit of normal is defined as the result of the
mean predicted value
(based on the patient's sex, age, and height)
Spirometry
Reduction in FEV1
• Airway obstruction is the most common cause of
reduction in FEV1
• Airflow obstruction may be secondary to
Bronchospasm (Asthma/ COPD)
Airway inflammation (Asthma/ COPD/ Bronchiectasis)
Loss of lung elastic recoil (Emphysema)
Increased secretions in the airway (Bronchitis/
Bronchiectasis/ Infection)
Assessing reversibility in airway
obstruction
• Response of FEV1 to inhaled bronchodilators is used to
assess the reversibility of airway obstruction (Post
Bronchodilator challenge)
• Methacholine Challenge – used to assess possible
underlying asthma, (ie reversible airway obstruction).
Baseline lung function may be normal when the patient
is clinically stable.
Assessing reversibility in airway
obstruction
• Gibson Resp Med
– 12% or 200ml
Reversible Airway Obstruction
Spirometry
Predicted
Measured
FEV 1 (l)
2.8
2.43
VC (l)
3.79
3.75
Post BD
Reversible Airway Obstruction
Spirometry
Predicted
Measured
Post BD
FEV 1 (l)
2.8
2.43
2.73
VC (l)
3.79
3.75
4.02
Indications for Lung Volume Tests
• Diagnose or assess the severity of restrictive lung
disease
• Differentiate between obstructive and restrictive disease
patterns
• Assess the response to therapy
• Make preoperative assessments of patients with
compromised lung function
Static lung volumes
• Total lung capacity (TLC)
– Total volume of air in the lungs at the end of an
maximal inspiration
• Residual volume (RV)
– Volume of air remaining in the lungs at the end of a
maximal expiration
• Functional residual volume (FRC)
– Volume of air remaining in the lungs at the end of tidal
expiration
Lung Volumes
Reduction in FVC
• A reduced FVC on spirometry in the absence of a
reduced FEV1 -to-FVC ratio suggests a restrictive
ventilatory defect
• An inappropriately shortened exhalation during
spirometry can (and often does) result in a reduced FVC
(i.e. Patient effort is important)
Causes of Abnormal Lung Volumes
• Raised TLC
– COPD esp. emphysema
– Transiently raised during an asthma exacerbation or
in the recovery phase of an asthma exacerbation
• Increased RV
– Airways disease (air-trapping), e.g. asthma or
emphysema
• Reduced TLC/ FVC/ RV
– Restrictive defect
(intrapulmonary or extrapulmonary)
Diffusion Capacity/ Transfer Factor
• The diffusing capacity is a measure of the conductance
of the CO molecule from the alveolar gas to
Haemoglobin in the pulmonary capillary blood
• CO (and oxygen) must pass through the alveolar
epithelium, tissue interstitium, capillary endothelium,
blood plasma, red cell membrane and cytoplasm before
attaching to the Haemoglobin molecule
Diffusion Capacity
Indications for Diffusion Capacity
• Evaluate or follow the progress of parenchymal/
interstitial lung disease
• Evaluate pulmonary involvement in systemic disease
• Evaluate obstructive lung disease
• Quantify disability associated with interstitial lung
disease
• Evaluate pulmonary hemorrhage
Diffusion capacity
• TLCO = transfer factor for the lung for carbon monoxide
i.e. Total diffusing capacity for the lung
– Same as DLCO
• KCO = transfer coefficent i.e. Diffusing capacity of the
lung per unit volume, standardised for alveolar volume
(VA)
• VA = Lung volume in which carbon monoxide diffuses
into during a single breath-hold technique
Abnormal Diffusion Capacity
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Low TLC
Low TLCO
Low/normal KCO
= Intrapulmonary restrictive defect
– Interstitial lung diseases
– Pulmonary oedema
• High TLC
• Low TLCO
• Low KCO
– emphysema
Abnormal Diffusion Capacity
• Low TLCO
• but high/N KCO
• = extrapulmonary restrictive defect
– Obesity
– Neuromuscular disease (respiratory muscle
weakness)
– Pleural disease e.g. effusion, thickening, tumor
– Skeletal deformity
– Post pneumonectomy
Abnormal Diffusion Capacity
• Normal/raised TLCO
• Raised KCO
– Asthma
– Pulmonary haemorrhage
Obstructive Lung Disease
• Chronic Obstructive Pulmonary Disease (COPD)
• Chronic Bronchitis
“Excessive mucus production, with a productive cough on
most days, for at least 3 months for 2 years or more.”
• Emphysema
– Primarily caused by cigarette smoking.
– Alpha -1-antitrypsin deficiency
– Environmental pollutants
Working Definition of COPD
Chronic obstructive pulmonary disease (COPD) is
characterised by airflow obstruction. The airflow obstruction
is usually progressive, not fully reversible and does not
change markedly over several months. The disease is
predominantly caused by smoking.
Airflow obstruction is defined as a reduced FEV1 (forced
expiratory volume in 1 second) and a reduced FEV1/FVC
ratio (where FVC is forced vital capacity), such that FEV1 is
less than 80% predicted and FEV1/FVC is less than 0.7.
(www.nice.org.uk/CG012NICEguideline)
Chronic Obstructive Pulmonary Disease
(COPD)
Characterized by:
– Dyspnoea at rest or with exertion
– Productive cough
– Barrel-chest (↑AP to Transverse diameter)
– Chest percussion: Hyper resonant
– Chest auscultation: Breath sounds distant or absent
– Chest X-Ray
• Flattened diaphragms
• Hyperinflated lung fields/ bullae
Emphysema
• Spirometry
Reduction in FEV1
Reduction in FEV1/ VC ratio
• Lung Volumes
Increased lung volumes (“air trapping”)
• Diffusing Capacity
Reduced
Obstructive Lung Disease
• Asthma
Airway obstruction is characterized by inflammation of
the mucosal lining of the airways, bronchospasm and
increased airway secretions
Reversible airway obstruction
Obstructive Lung Disease
• Asthma Triggers
• Exercise/ Cold air
• Allergic agents
– Pollens, house dust mite, animal dander,
moulds
• Non-allergic agents
– Viral infections, environmental
pollutants, medication, food additives,
emotional upset
• Occupational exposure
– Cotton/ wood dusts, grains, metal salts,
insecticides
Obstructive Lung Disease
• Asthma
During Attacks
– Peak Flow (PEF) is reduced/ Hypoxia
– Response to bronchodilators
• Spirometry
Reduced FEV1
• Lung Volumes
Increased (Hyperinflation)
• Diffusion Capacity
Normal
During stable state: Spirometry may be normal
Causes of Restrictive Spirometry
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Pulmonary fibrosis
Pleural effusion
Pleural tumors
Lung resection (lobectomy/ pneumonectomy)
Diaphragm weakness or paralysis
Neuromuscular disease
Kyphoscoliosis
Obesity
Inadequate respiration secondary to pain
Congestive heart failure
Ascites
Pregnancy
Restrictive Lung Disease
• Idiopathic Pulmonary Fibrosis
Or secondary to
• Treatment with bleomycin, cyclophosphamide,
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methotrexate or amiodarone
Autoimmune diseases: Rheumatoid arthritis, systemic
lupus erythematousus (SLE), scleroderma
Sarcoidosis
Pneumoconiosis
– Silicosis – Silica dust
– Asbestosis – Asbestos fibers
Restrictive Lung Disease
• Idiopathic Pulmonary Fibrosis
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Increasing exertional dyspnoea
Dry cough
Finger clubbing
Inspiratory crackles on auscultation
– Chest X-Ray
• Interstitial infiltrates are visible
• Honeycombing pattern
Restrictive Lung Disease
• Idiopathic Pulmonary Fibrosis
• Spirometry
Reduced VC
• Lung volumes
Reduced TLC/ RV
• Diffusion capacity
Reduced
Diseases of Chest Wall and Pleura
Disorders involving the chest wall or pleura of the lungs
result in restrictive ventilatory defects on pulmonary
function testing. But, lung parenchyma is not affected.
Diseases of Chest Wall and Pleura
• Spirometry
Reduced FEV1 and FVC
• Lung Volumes
Reduced TLC
• Diffusion Capacity
Reduced
• KCo
Normal
Obstructive v. Restrictive
Mixed Picture
• Bronchiectasis
Pathologic and irreversible dilatation of the bronchi,
resulting from destruction of the bronchial wall by severe,
repeated infections and inflammation
Bronchiectasis
Post infective:
Whooping cough/ TB
Genetic:
Cystic Fibrosis/ Primary Cliliary Dyskinesia (PCD)
Immunodeficiency
Bronchiectasis
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Dyspnoea
Significant productive cough
Purulent, foul smelling sputum
Haemoptysis
Frequent pulmonary infections
Chronically unwell
Chest X-Ray / CT Scan
• Airway Dilation
Airway Function Tests
Flow Volume Loop (FVL)
Airway Function Tests
Flow Volume Loop (FVL)
Respiratory History
• Dyspnoea: Do you get short of breath at the following times:
• At rest? On exertion? At night?
• Progression of dyspnoea
• Cough: Do you ever cough?
• In the morning? At night?
• Dry or productive?
• Blood?
• Sputum/ Phlegm? (Color, volume, consistency)
• Chest pain/ Orthopnoea/ Paroxysmal Nocturnal Dyspnoea
• Family history of lung disease
• Past History
• TB/ Emphysema/ Chronic Bronchitis/ Asthma
• Recurrent lung infection/ Pneumonia or pleurisy
• Allergies or hay fever
• Previous chest injury or chest surgery
Respiratory History
• Current Medications
• Inhalers/ Steroids/ Nebulised bronchodilators or antibiotics/
Oxygen/ Mucolytics
• Cardiac medications
• Oncology drugs or immunosuppressives
• Smoking Habits
• Cigarettes/ Cigars/ Pipe/ Illicit drugs
• How many years?
• Current or ex smoker?
• Occupation
• Asbestos (Direct/ Bystander exposure)
• Mining, quarry, foundry
Invisible Lives Report - BLF
1. The disease is far from invisible statistically: it is the UK’s
fifth biggest killer disease, claiming more lives than breast,
bowel or prostate cancer (estimated 30 000 lives/ year)
2. The second most common cause of emergency admission to
hospital and one of the most costly inpatient conditions
treated by the NHS
3. It is estimated that the direct cost of providing care in the
NHS for people with COPD is almost £500 million a year –
more than half of which relates to hospital care
Invisible Lives Report - BLF
1. The epidemiological evidence published in 2006
suggesting that out of an estimated 3.7 million people in
the UK with COPD, only 900,000 were currently
diagnosed and receiving treatment and care
2. The remaining 2.8 million people were still unaware they
had a disease which, if left untreated, could severely
restrict their lives and would eventually kill them
Diagnosis
• Clinical suspicion in patients (usually smokers or exsmokers, age >35yrs) with:
– exertional breathlessness
– chronic cough
– regular sputum production
– frequent “winter bronchitis”
– wheeze with a risk factor (usually smoking)
• Airflow obstruction should be confirmed with
spirometry
Spirometry for COPD Diagnosis:
NICE 2010
– FEV1 <80% predicted
– Post Bronchodilator FEV1:FVC ratio <0.7
– Stage 1 Mild:
– Stage 2 Moderate:
– Stage 3 Severe:
– Stage 4 Very Severe:
or
– Stage 4 Very Severe:
FEV1 80% (+ Symptoms)
FEV1 50-79%
FEV1 30-49%
FEV1 <30%
FEV1 <50%
(+Respiratory Failure)
General principles of management
of stable COPD – NICE guidelines
• Lifestyle modification
– Smoking cessation
(Behavioural support/ Nicotene replacement/
Bupropion/ Varenicline)
– Pulmonary rehabilitation
• Optimisation of pharmacological therapies
– Inhalers
• Short-acting bronchodilators
• Long-acting bronchodilators regularly, often
combined with…
• Corticosteroids (FEV1 </= 50% with 2+
exacerbations requiring antibiotics or oral
steroids in 1 year)
Maintenance therapy with budesonide and formoterol in
chronic obstructive pulmonary disease
Calverley et al. Eur Respir J 2003;22:912–919.
Seretide reduces the rate of exacerbations
needing medical intervention
TORCH
per patient per year
mean exacerbation rate
p=0.002
Seretide Fluticasone Salmeterol placebo
Adapted from:
Calverley PM. et al.N Engl J Med 2007;356:775-89.
General Principles of Guidelines
• Theophylline, oral steroids, diuretics, mucolytics
• Prophylaxis
– Immunisations (influenza, pneumococcus, H1N1)
• Long Term Oxygen Therapy (LTOT)
• Surgery
– Bullectomy, lung volume reduction, transplant
• Management of anxiety and depression
• Palliation and end of life support
General Principles - in addition
• Early detection + Patient education + Smoking cessation
• Treatment of acute exacerbations
• Pulmonary Rehabilitation:
Increases threshold for perception of dyspnoea
Improves quality of life
Substantially reduces health care costs
Under resourced
• NIPPV:
Reduces need for invasive ventilation
Reduces admissions
Bridging measure prior to surgery
Under resourced
Referral for Specialist advice - NICE
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Diagnostic uncertainty
Suspected severe COPD
Onset of cor pulmonale
Assessment for oxygen
therapy, long-term
nebuliser
therapy or oral
corticosteroid therapy
Bullous lung disease
Rapid decline in FEV1
Assessment for
pulmonary rehabilitation
• Assessment for lung
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volume reduction surgery
or transplantation
Patient aged under 40
years or a family history
of alpha-1
antitrypsin deficiency
Symptoms
disproportionate to lung
function deficit
Frequent infections
Haemoptysis
Complications of COPD
• Respiratory failure
• Cor pulmonale
• Bullae
• Pneumothorax
• Pneumonia
• Increased risk of malignancy (shared risk factor)
Preoperative measures
• Cessation of cigarette smoking for at least 8 weeks
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before surgery
Treat airflow obstruction
Treat respiratory infection if present
Educate for lung-expansion manouvres
Mucolytics/ Physiotherapy and chest clearance
• Postoperative measures
• Epidural analgesia or intercostals nerve bloc for pain
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control
Early mobilization
Chest physical therapy (including deep breathing and
incentive spirometry)
Continuous positive airway pressure in selected patients
Pre Operative Assessment
• Be wary of a “presumed diagnosis” of lung disease
• Beware of “no previous diagnosis of known lung
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disease”
Evaluate lung function systematically
Careful history and examination
If in doubt…..
Find a friendly respiratory physician