Chronic obstructive pulmonary disease other diagnostic studies

Chronic obstructive pulmonary disease Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Chronic obstructive pulmonary disease from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic Study of Choice
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X Ray
Echocardiography or Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Future or Investigational Therapies
Case Studies
Case #1
Chronic obstructive pulmonary disease other diagnostic studies On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Chronic obstructive pulmonary disease other diagnostic studies All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Chronic obstructive pulmonary disease other diagnostic studies
CDC on Chronic obstructive pulmonary disease other diagnostic studies
Chronic obstructive pulmonary disease other diagnostic studies in the news
Blogs on Chronic obstructive pulmonary disease other diagnostic studies
Directions to Hospitals Treating Chronic obstructive pulmonary disease
Risk calculators and risk factors for Chronic obstructive pulmonary disease other diagnostic studies

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Philip Marcus, M.D., M.P.H. [2]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [3]

Overview

Six minute walk tests act as a predictor of mortality in patients with moderate COPD (patients who desaturate have worse mortality compared with those who don't desaturate.)

Other Diagnostic Studies

Pulmonary Function Test / Spirometry

• COPD is particularly characterized if a ratio of forced expiratory volume over 1 second (FEV₁) to forced vital capacity (FVC) being < 0.7 and the FEV₁ < 70% of the predicted value when compared with a matched control. , (see Spirometry).
• Normally, at least 70% of the FVC comes out in the first second (i.e. the FEV₁/FVC ratio is >70%). A ratio less than normal defines the patient as having COPD.
• More specifically, the diagnosis of COPD is made when the FEV₁/FVC ratio is <70%.
• The GOLD criteria also require that values are after bronchodilator medication has been given to make the diagnosis,
• The NICE criteria also require FEV1%.
• According to the ERS criteria, it is FEV1% predicted that defines when a patient has COPD, that is, when FEV1% predicted is < 88% for men, or < 89% for women.
• Spirometry can help to determine the severity of COPD.
• The FEV₁ (measured after bronchodilator medication) is expressed as a percentage of a predicted "normal" value based on a person's age, gender, height and weight:
• The severity of COPD also depends on the severity of dyspnea and exercise limitation. These and other factors can be combined with spirometry results to obtain a COPD severity score that takes multiple dimensions of the disease into account.

COPD Severity

The severity of COPD can be classified as follows using spirometry

Severity	FEV1 /FVC	FEV1 % predicted
At risk	>0.7	≥80
Mild COPD	≤0.7	≥80
Moderate COPD	≤0.7	50-80
Severe COPD	≤0.7	30-50
Very Severe COPD	≤0.7	<30 or 30-50 with Chronic Respiratory Failure symptoms

Six Minute Walking Distance

• It act as a good predictor of mortality in patients with COPD.
• Patients who desaturate during 6MWD have higher mortality compared to those who doesn't desaturate.
• This test is a part of BODE index which is used as a mortality predictor for patients with COPD.
• The BODE index has the following component
  • Body mass index
  • Obstruction (FEV1)
  • Dyspnea (MMRC dyspnea scale)
  • 6 minute walking distance.

Right Sided Heart Catheterization

• It is not routinely done. However, in cases when pulmonary hypertension is suspected clinically and on echocardiography then a right heart catheterization can be done to measure pulmonary artery pressure and see the response of vasodilators