Lung Function Tests Sema Umut Lung Factors Affecting
- Slides: 67
Lung Function Tests Sema Umut
Lung Factors Affecting Function Mechanical properties Resistive elements
Mechanical Properties Compliance Describes the stiffness of the lungs Change in volume over the change in pressure Elastic recoil The tendency of the lung to return to it’s resting state
Resistive Properties Determined by airway caliber Affected by Lung volume Bronchial smooth muscles Airway collapsibility
A TEST SHOULD BE Acceptabile, easy Noninvasive Cost effective Informative Reproducible
Spirometry Acceptabile, easy Noninvasive Cost effective Inexpensive Informative Reproducible
Spirometry It is the most commonly used lung function screening study It should be the clinician's first option
When can spirometry help us? - Diagnosing disease - Monitoring disease - Prognosis - Directing therapy
Indications for Spirometry Diagnostic To evaluate symptoms, signs, or abnormal laboratory tests Dyspnea Wheezing Cough Abnormal breath sounds Overinflation Expiratory slowing Cyanosis
Abnormal laboratory tests Hypoxemia Hypercapnia Polycythemia Abnormal chest radiographs
To screen individuals at risk of having pulmonary diseases Smokers Individuals in occupations with exposures to injurious substances
Indications for Spirometry To assess preoperative risk To assess health status before physical activity programs To evaluate therapy
Disability/Impairment Evaluations To assess individuals for legal reasons
Prognosis Survival predictor of general population Copenhagen City Heart Study 13, 900 subjects for 25 yrs Lange P. J Clin Epidemiol 1990; 43: 867 -873. Cox proportional hazards FEV 1/ht 2 best index Framingham study
Spirometry Requirements 1. Good equipment 2. Good technicians (efor dependent) 3. Good clinicians - correct indication - correct use / presentation of the data - correct decision making
Pulmonary Function Testing relates Age : Smaller lung volumes as we age Gender : The lung volumes of males are larger than females Height Race
Perform manoeuvre Attach nose clip, place mouthpiece in mouth Inhale completely and rapidly Exhale maximally until no more air can be expelled Repeat for a minimum of 3 manoeuvres
Forced Vital Capacity FVC Total volume of air expired forcefully after a full inspiration Patients with restrictive lung disease have a decreased vital capacity
Slow Vital Capacity (SVC) This is the total volume of air expired slowly after a full inspiration If the SVC is greater than FVC, it indicates the presence of obstructive disease
Forced Expiratory Volume in 1 Second FEV 1 Volume of air expired in the first second during maximal expiratory effort
FEV 1/FVC Percentage of the forced vital capacity which is expired in the first second of maximal expiration to forced vital capacity In health the FEV 1/FVC is usually around 80% Decrease in FEV 1/FVC means obstruction
Tidal volume TV The volume of air moved during normal quiet breathing (about 0. 5 L)
RESIDUEL VOLUME (RV) The volume of air remaining in the lungs after a forceful expiration (about 1. 0 L).
FUNCTIONAL RESIDUEL CAPACITY(FRC) The amount of air remaining in the lungs after a normal quiet expiration
TOTAL LUNG CAPACITY (TLC) It is the volume of air in the lungs when the person has taken a full inspiration TLC = RV + VC
TLC, RV, FRC Can not be measured by spirometry Helium dilution Nitrogenmetry Body plethysmography
INTERPRETATION OF SPIROMETRY Compare the measured values of the patient with normal values derived from population studies The percent predicted normal is used to define normal and abnormal and to grade the severity of the abnormality
Categories of Disease Obstructive Restrictive Mixed
Spirogram measures two components - air flow and volume If flow is reduced, the defect is obstructive If volume is reduced the defect is restrictive
Interpretation FVC and FEV 1 are normal – NORMAL FVC is low but FEV 1/FVC is >80 RESTRICTIVE FEV 1/FVC < 70% OBSTRUCTIVE
Spirometry Obstruction (FEVı /FVC) < %70
Obstructive Lung Diseases Asthma Chronic obstructive pulmonary disease
COPD -COPD is characterized by airflow limitation that is not fully reversible -The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases
Diagnosis of COPD SYMPTOMS cough sputum shortness of breath EXPOSURE TO RISK FACTORS tobacco occupation indoor/outdoor pollution è SPIROMETRY
Asthma is a chronic inflammatory disease of the airways Inflammation causes the airways to narrow periodically This produces wheezing and breathlessness Obstruction to air flow is reversible
Bronchodilator Test Evaluates how responsive the patient is to a bronchodilator medication Spirometry is repeated about 15 minutes after giving a bronchodilator (400 mg salbutamol)
WHY TEST FOR REVERSIBILITY? To determine best function To follow rate of change in PFTs over time To exclude asthma To determine response to therapy
REVERSIBILITY Increase of 200 ml or 12 -15% of the baseline FEV 1 shows REVERSIBLE OBSTRUCTION 40 Both drugs combined 30 20 10 0 0 2 4 6 8
Restriction means a decrease in lung volumes
Extrinsic Restrictive Lung Disorders. Neuromuscular Disorders. Scoliosis, Kyphosis. Rib fractures. Pleural Effusion. Pregnancy. Gross Obesity. Tumors. Ascites
Intrinsic Restrictive Lung Disorders Pnuemonectomy Pneumonia Lung tumors Interstitial lung diseases Sarcoidosis Lung oedema
Flow – Volume Loop is a measure of how much air can be inspired and expired from the lungs It is a flow rate measurement
Restrictive Lung Disease Characterized by diminished lung volume Decreased TLC, FVC Normal FEV 1/FVC ratio
Large Airway Obstruction can be detected by Flow – Volume Loop Characterized by a truncated inspiratory or expiratory loop
Extra-thoracic Upper Airway Obstruction
Peak Expiratory Flow Rate PEFR The maximum flow rate during the forced vital capacity maneuver Useful to monitor asthma
Measuring PEF must be achieved as rapidly as possible and at a high lung volume as possible The subject must be encouraged to blow as vigorously as possible
When is PEF useful? PEF can be very useful in diagnosing occupational asthma
ARTERIAL BLOOD GASES INDICATION Oxygenation Ventilation Acid-Base Status
ARTERIAL BLOOD GASES Blood gases is a measurement of how much oxygen and carbon dioxide is in the blood Determines the acidity (p. H) of the blood
ARTERIAL BLOOD GASES Blood is taken from an artery The blood may be collected from the radial artery, the femoral artery , or the brachial artery
ARTERIAL BLOOD GASES After the blood is taken, pressure is applied to the site for a few minutes to stop the bleeding The sample must be quickly sent to a laboratory
Blood Gas Report p. H Pa. CO 2 (mm Hg) Pa. O 2 (mm Hg) HCO 3 - (mmol/L) B. E. (mmol/L) O 2 saturation 7. 4 40 110 - 0. 5(age) 24 0 >90%
Causes of a low Pa. O 2 V/Q mismatch Dead space ventilation Shunt Diffusion Impairment Alveolar Hypoventilation Altitude
Alveolar Hypoventilation Reduced Respiratory Drive Pump failure
ANALYSIS OF VENTILATON Hypercapnea > 45 mm Hg Hypoventilation Respiratory Acidosis Hypocapnea < 35 mm Hg Hyperventilation Respiratory Alkalosis
Respiratory alkalosis Low levels of carbon dioxide in the blood due to alveolar hypervetilation (breathing excessively)
Respiratory acidosis The kidneys and lungs maintain the body's acid/base (p. H) balance Respiratory acidosis develops when carbon dioxide is elevated Primarily caused by alveoler hypoventilation ( decreased breathing)
Pitfalls Venous Sample _Pa. O 2 = 40, Pa. CO 2 = 45 Free flow into syringe Air-bubble in syringe Falsely elevated Pa. O 2 Arterial blood sample should be transported on ice under anaerobic conditions
Spirometry is essential in respiratory evaluation as tension arterial measurement is essential in cardiovascular evaluation
- Hypervetilation
- Sema umut
- Ace different help iq tests still
- Factors affecting the merchandising function
- Self adjusting computation
- Sistemler kuramı çerçeve çalışması
- Umut tunga
- Umut oban
- Tire umut psikolojik danişmanlik merkezi
- Umut i̇nternet
- Prof umut dilek
- Umut al
- Umut
- What factors affect the weather
- Factors affecting microbial growth in food
- Factors affecting magma viscosity
- Factor affecting volcanic eruption
- Factors affecting carburetion
- Differential thermal analysis
- Factors affecting housing choices
- Factors of bilingualism
- Human movement impact factor
- Stroke volume normal
- Factors affecting movement in physical education
- Baricity of local anesthetics
- Eluviation vs illuviation
- Factors affecting health
- Explain the factors affecting chemical equilibrium
- Factors affecting sample size
- Factors affecting planning
- Factors affecting rate of cooling
- Psychological factors affecting sports performance
- Physiological factors affecting performance
- Factors affecting absorption of drug
- Map co svr
- Average revenue
- Factors affecting span of control
- Cuspal inclination
- Factors affecting bacterial growth ppt
- Contingency factors affecting structural choice
- Factors affecting evapotranspiration
- Factors affecting milling process
- What are the factors affecting the climate
- Factors affecting enzyme activity bbc bitesize
- Filtration fraction
- What factors affect optimum weight
- Factors affecting fermentation
- Factors affecting fermentation
- Powder flowing angle
- Human factors in interior design
- Factors affecting interior design
- Factors of influencing communication
- Local factors affecting wound healing
- The lower the activation energy the faster the reaction
- Factors affecting projectile trajectory
- Population growth factors
- Factors affecting organizational structure
- Factors affecting option prices
- What are the factors affecting motion
- What are the intrinsic factors for the microbial growth
- Factors affecting interpersonal skills
- Factors affecting human resource management
- Equilibrium factors
- Factors affecting bulk density of powders
- Ph partition theory of drug absorption
- Service layout
- Esp course design sample
- Factors affecting entrepreneurship development