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COPD Problems in Diagnosis. Lütfi Çöplü M.D. Hacettepe University School of Medicine Chest Department. Diagnosis of COPD. Medical History Cough, sputum production, dyspnea Risk factors /Smoking history Physical examination Assesment of airway obstruction. Physical Examination.
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COPD Problems in Diagnosis Lütfi Çöplü M.D. Hacettepe University School of Medicine Chest Department
Diagnosis of COPD • Medical History Cough, sputum production, dyspnea Risk factors /Smoking history • Physical examination • Assesment of airway obstruction
Physical Examination Erken dönemde • İncreased expirium • Wheezing in forced expirium • Barrel chest • Chest wall expansion Ü • Sonority Û • Respiratory soundsi Ü • Ronchi • Heart Sounds Ü • Pursed lips breathing • Intercostal retraction • Juguler venous distention • Liver enlargement • Cyanosis • Pheripheral edema Hastalık geliştiğinde Terminal dönemde
Diagnosis of COPD RISK FACTORS SYMPTOMS smoking cough occupation sputum dyspnea air pollution è SPIROMETRY
Diagnostic Tests • CBC and biochemistry • ABG analysis • Sputum analysis • ECG • -1 antitrypsin • Quality of life, Dyspnea scores • Respiratory muscle function • Exercise capacity • Tests for pulmonary arterial hypertension • Sleep studies • Pulmonary function tests • Spirometry • Reversibility • Lung volumes • Diffusion test • PEF • CXR (or thorax CT)
FEV1 FVC FEV1/FVC Normal 4.150 5.200 %80 COPD 2.350 3.900 %60 Ekspirasyon TLC FRC RV İnspirasyon Spirometry Flow-Volume Loop Flow-Time Curve 0 1 2 3 4 5 Litre FEV1 COPD FEV1 Normal FVC 1 2 3 4 5 6 Saniye GOLD Executive Summary, NIH, 2003
Reversibility Test • Increase in FEV1 > %12 and >200 ml • 400 µg salbutamol or terbutaline should be given • Asses the response in 15 minutes GOLD NHLBI/WHO Workshop Report. 2004 ATS 1995 BTS NICE Guideline – Chronic obstructive pulmonary disease.2004
Peak Expiratory Flow (PEF) • There is poor relationship between PEF and FEV1 in COPD patients • It is impossible to predict FEV1 from the PEF Bourbeau J Comprehensive Management of COPD 2002
Lung Volumes TLC IC TLC Hacim IRV IC VT FRC/EELV ERV FRC/EELV RV Normal KOAH *FRC=TGV
Spirometry and other PFTs Bourbeau J Comprehensive Management of COPD 2002
Radiology • CXR is insensitive detecting airflow obstruction • CXR of patient with mild COPD is likely to be normal Bourbeau J Comprehensive Management of COPD 2002
Diagnosis of COPD RISK FACTORS SYMPTOMS smoking cough occupation sputum dyspnea air pollution è SPIROMETRY
Spirometry • How does the patient perform maneuvers? • Are they delivered with maximal effort and with a “blast” at the start? • Are the maneuvers delivered without hesitation? • Does leakage occur at the mouth piece? • Does the maneuvers end prematurely? Enright PL et al Eur Respir Mon 2005
Spirometry Quanjer P, www.spirxpert.com
Six Second Manoeuvres • FEV6 is more reproducible than the traditional FVC • The use of six second manoeuvres reduces technologist and patient fatigue • Also eliminates the risk of syncope • However reference equations for FEV6 are not widely avaliable Enright PL et al Eur Respir Mon 2005
PFT results of 5114 patients were retrospectively anaysed • When FEV1/FVC is taken gold standard • Negative predictive value 92,4 % • Sensitivity 86,09 %
Problems in Spirometry Practice Spirometry in primary care ?
A prospective, randomized, comparative trial was planned involving 57 Italian pulmonology centers and 570 GPs who had to enroll consecutive subjects aged 18 to 65 years with symptoms of asthma or COPD without a previous diagnosis. • Patients were randomized 1:1 into two groups with an interactive voice responding system: conventional evaluation alone vs conventional evaluation and spirometry. • Office spirometry was performed by GPs who were trained by reference specialists using a portable electronic spirometer
Of 333 patients enrolled, 136 nonrandom violators completed the protocol. • Per-protocol analysis showed a concordant diagnosis between GPs and specialists in 78.6% of cases in the conventional evaluation-plus-spirometry group vs 69.2% in the conventional evaluation group (p =0.35). • In the intention-to-treat analysis, the respective percentages of concordant diagnosis were 57.9 and 56.7 (p =0.87).
Frequent protocol vialation and inadequate sample size did not allow us to prove a significant advantage of office spirometry in improving the diagnosis of asthma and COPD
A prospective survey of the population aged 35 to 70 years (n=3408) visiting the GP during a 12-week period, using a questionnaire on symptoms of obstructive lung disease (OLD). • Spirometry was performed in all participants with positive answers and in a 10% random sample from the group without complaints.
The positive predictive power of the questionnaire was low (sensitivity, 58%; specificity, 78%; likelihood ratio, 2.6). • Despite a negative predictive value of 95% for the questionnaire used, 42% of the newly diagnosed cases of OLD would not have been detected without spirometry.
The use of a spirometer is mandatory if early stages of OLD are to be detected in general practice. • Screening for airflow obstruction almost doubles the number of known patients with OLD.
Targets Population for Spirometry Screening • All smokers 35 years of age and over • Current or past smokers with a 20 pack-year history of smoking • Patients with recurrent or chronic respiratory symptoms • Patients with occupational exposure to irritants • Family history of obstructive pulmonary disease • History of hyperresponsiveness to provocative agents • Patient with childhood risk factors that may be associated COPD Bourbeau J Comprehensive Management of COPD 2002
Problems in Spirometry Practice Can all patients with COPD be diagnosed correctly?
ATS/ERS Task Force characterizes obstruction as a FEV1/FVC% below the statistically defined fifth percentile of normal. • However, many recent publications continue to use GOLD criterion that defines obstruction as a FEV1/FVC% < 70%. • Data from NHANES-III should identify and quantify differences, help resolve this conflict, and reduce inappropriate medical and public health decisions resulting from misidentification.
Airway Obstruction • FEV1/FVC < 70 % or • FEV1/FVC % below the statistically defined 5th percentile of normal (LLN)
Methods Individual values of FEV1/FVC % and LLN compared by decades in 5906 healthy never-smoking adults and 3497 current smokers
40 C-S N-S % of normals misidentified as normals 20 0 % of Misidentified Subjects -20 -40 C-S N-S -60 % abnormals misidentified as normals 3 4 5 6 7 8
RESULTS Nearly one half of young adults with FEV1/FVC % below fifth percentile of normal were misidentified as normal Approximately one fifth of older adults with observed FEV1/FVC % above the fifth percentile had FEV1/FVC %ratios < 70 % (normals misidentified as abnormal)
CONCLUSION • The main crux of diagnosis of COPD by GOLD criteria are flawed • This will lead to more older subjects being diagnosed with COPD than is justified • As well as lead to false negative findings in younger subjects • Scientific community in Respiartory Medicine move to correct this anomaly Quanjer P, www.spirxpert.com
As part of the Copenhagen City Heart Study, 8045 men and women aged 30–60 years withnormal lung function at baseline were followed for 25 years. • Lung function measurements were collected and mortality from COPD during the 25 year observation period was analysed.
The percentage of men with normal lung function ranged from 96% of never smokers to 59% of continuous smokers; for women the proportions were 91% and 69%, respectively. • The 25 year incidence of moderate and severe COPD was 20.7% and 3.6%, respectively, with no apparent difference between men and women.
The absolute risk of developing COPD among continuous smokers is at least 25%, which is larger than was previously estimated.
Follow-Up Assessment • COPD patients are followed up no systemic manner • Frequency of visits and the need for investigations vary between physicians • Age under 40 years, smoking history of less than 10 pack years and disabled patients should be refered to respirologist