Maggie Harris Independent Respiratory Nurse Specialist

Diagnosing COPD – NICE guidelines Practical use of Spirometry – QOF Principles of Spirometry – Spirometry Guidelines 2013 Spirometry case studies

0 Chronic obstructive pulmonary disease A few slides of NICE’s view on diagnosing COPD 3 rd. Edition - April 2012 NICE clinical guideline 101

Definition of COPD Airflow obstruction is defined as reduced FEV 1 /FVC ratio (< 0.7) It is no longer necessary to have an FEV 1 < 80% predicted for definition of airflow obstruction If FEV 1 is ≥ 80% predicted, a diagnosis of COPD should only be made in the presence of respiratory symptoms, for example breathlessness or cough COPD produces symptoms, disability and impaired quality of life which may respond to pharmacological and other therapies that have limited or no impact on the airflow obstruction. FEV 1 = forced expiratory volume in 1 second FVC = forced vital capacity

Diagnose COPD Consider a diagnosis of COPD for people who are: over 35, and smokers or ex-smokers, and have any of these symptoms: - exertional breathlessness - chronic cough - regular sputum production, -frequent winter ‘bronchitis’ -Wheeze And no clinical features of asthma [2004]

Diagnose COPD: Spirometry Perform spirometry if COPD seems likely [2004] The presence of airflow obstruction should be confirmed by performing post-bronchodilator spirometry [new 2010] Consider alternative diagnoses or investigations in: - older people without typical symptoms of COPD where the FEV1/FVC ratio is < younger people with symptoms of COPD where the FEV1/FVC ratio is ≥ 0.7 [new 2010] All health professionals involved in the care of people with COPD should have access to spirometry and be competent in the interpretation of the results [2004]

Differentiating COPD from asthma: 2 If diagnostic uncertainty remains, the following findings should be used to help identify asthma: - FEV 1 and FEV 1 /FVC ratio return to normal with drug therapy - a very large (>400ml) FEV 1 response to bronchodilators or to 30mg prednisolone daily for 2 weeks - serial peak flow measuremenst showing significant (20% or greater) diurnal or day-to-day variability - remaining diagnostic uncertainty may be resolved by referral for more detailed investigations [2004]

Diagnose COPD: assessment of severity Assess severity of airflow obstruction using reduction in FEV 1 NICE clinical guideline 12 (2004) ATS/ERS 2004GOLD 2008NICE clinical guideline 101 (2010) Post- bronchodilator FEV 1 /FVC FEV 1 % predicted Post- bronchodilato r < 0.780%MildStage 1 (mild)Stage 1 (mild)* < 0.750–79%MildModerateStage 2 (moderate) < 0.730–49%ModerateSevereStage 3 (severe) < 0.7< 30%SevereVery severeStage 4 (very severe)** * Symptoms should be present to diagnose COPD in people with mild airflow obstruction ** Or FEV 1 < 50% with respiratory failure [new 2010]

Asthma QOF AST indicator 002 – a few quotes ( see handouts of pages 90 & 91) If asthma is probable In symptomatic patients airway obstruction may be demonstrated by spiometry……. Increases of >400mls are strongly suggestive of asthma…….. Normal spirometry, however, does not exclude asthma: indeed the variable nature of asthma means that many of the milder patients seen in primary care will be asymptomatic at the time of the lung function test and will have completely normal lung function with no reversibility at the time of testing

Asthma QOF continued:- Variability of PEF. This may be demonstrated by monitoring diurnal variation, or day to day variation (recorded twice a day for two weeks using the same peak flow meter)….. Significant reversibility is a change of 20% and >60 l/min (20% in children)…. A trial of treatment, with repeated lung function measurements and/or symptoms scores over time will demonstrate objective improvement………. If the probability of asthma is intermediate Spirometry is the key investigation ………

COPD QOF COPD Rationale – afew quotes (see separate handout of page 97) A diagnosis of COPD relies on clinical judgment based on a combination of history, physical examination an confirmation of the presence of airflow obstruction using spirometry…… The NICE clinical guideline requires post bronchodilator spirometry for diagnosis…… Routine reversibility testing is not recommended. However where doubt exists as to whether the diagnosis is asthma or COPD, reversibility testing may add additional information to post bronchodilator readings….

Obstructive airways disorders (e.g. COPD, asthma) = obstruction of flow Restrictive diseases (e.g. fibrotic lung diseases etc.) = restriction of volume Spirometry should only be used as a confirmation of disease, following history and symptoms –FEV1 is a poor predictor of health status Spirometry is a measure of lung function and is a reliable method of differentiating between:-

We do spirometry for a number of reasons:- – Confirmation of diagnosis of COPD, following assessment of symptoms and history – COPD patients annually for assessing deterioration of disease – To diagnose asthma in a very few patients who are difficult to diagnose (use peak flow home monitoring in majority of cases) – Always follow contra-indications for the appropriate test When so we perform Spriometry

 FEV1 – Forced Expiratory Volume in 1 second (on fast blow)  VC, RVC or EVC – Maximum lung capacity attainted on a slow blow  FVC – Forced Vital capacity – maximum lung capacity attained on a fast blow  Ratio – FEV1/FVC or FEV1/VC = FEV1 divided by the largest volume of either the FVC or VC  FEF 25-75, MEF – small airways Terminology

A Technically Acceptable curve A technically acceptable curve should be smooth, upward curving with no irregularities and should reach a plateau VOLUME INLITRESVOLUME INLITRES Seconds FEV1 FVC Obstructed pattern Normal pattern A Volume Time Trace Restricted pattern

FlowLsecFlowLsec Volume (Litres) FVC Peak Flow Normal flow volume trace

FlowLsecFlowLsec Volume (Litres) FVC Peak Flow Obstructed flow volume trace

FlowLsecFlowLsec Volume (Litres) FVC Severe Obstructed flow volume trace “Church Steeple”

Air Trapping With air trapping, there could be more air blown out in the VC rather than FVC If you use FVC for the diagnosis, it may look like a restrictive pattern So you need to use the VC if larger, to get the correct diagnosis vol. Seconds FVC 1 sec FVC FEV1 FEV1/VC<70% = Obstructive Pattern VC

Diagnosis Flow Start ?Abnormalities on graph Ratio Reduced <70% % Pred. FVC or VC (use largest) < 80% Obstructive Combined (obstructive & restrictive) Restrictive Normal % Pred FEV1 indicates severity of Obstruction Yes No Yes No FEV1 % Predicted > 80% = mild (with symptoms) 50 – 79% predicted = moderate 30 – 49% predicted = severe < 30% predicted = very severe

Spirometry Guidelines April

New guidelines for spirometry – see PCC Spirometry guidelines – Association for Respiratory Technology & Physiology ; - NICE/BTS Guidelines - nice guideline.pdfwww.nice.org.uk/pdf/CG012 nice guideline.pdf GMS Contract parameters of Spirometry predicted values References