Essen%als of Spirometry and Assessment

Transcription

1 Essen%als of Spirometry and Assessment Objectives: 1. Review spirometric acceptability, reproducibility and reporting standards 2. Discuss lung volumes and capacities 3. Discuss Pre & Post bronchodilator studies 4. Review relevant lab values 1 Essen&als of Spirometry and Assessment Spirometry Assesses the mechanical proper&es of the lung by measuring expiratory volumes and flow rates. - At least (3) acceptable efforts are performed to ensure repeatability of results - Select (best test) maneuver with largest sum of FVC+FEV 1 to determine other values - Report the highest FVC regardless of trial that it comes from. the 2 1

2 Lung Volumes IRV TV IC VC TLC 4 Volumes 4 Capaci&es Sum of 2 or more lung volumes ERV FRC RV RV 3 Tidal Volume (Vt) IRV IC VC Vt TLC ERV FRC RV RV Volume of air inspired and expired during normal quiet breathing Measured with a spirometer Normal=500 ml Decreased with restrictive disease 4 2

3 Inspiratory Reserve Volume (IRV) IRV IC VC Vt TLC ERV FRC RV RV The maximum amount of air that can be inhaled after a normal tidal volume inspiration Measured with a spirometer Normal: 3100 ml Decreased with restrictive disease IRV=IC-VT or, IRV=VC-ERV-VT 5 Inspiratory Capacity (IC) IRV IC VC Vt TLC ERV FRC RV RV Maximum amount of air that can be inhaled from resting end expiration Measured with a spirometer IC = IRV + VT, or IC=VC-ERV, or IC=TLC-FRC Normal 3600 ml Decreased with restrictive disease 6 3

4 Expiratory Reserve Volume (ERV) IRV IC VC Vt TLC ERV FRC RV RV Maximum amount of air that can be exhaled from the resting expiratory level Measured with a spirometer Normal 1200 ml Decreased with restrictive disease ERV=VC-IC, or ERV=FRC-RV 7 Residual Volume (RV) IRV IC VC Vt TLC ERV FRC RV RV Volume of air remaining in the lungs at the end of maximum expiration Cannot be measured with a simple spirometer Normal 1200 ml Decreased with restrictive and with increased obstructive RV=FRC-ERV,or RV=TLC-VC 8 4

5 Func&onal Residual Capacity (FRC) IRV IC VC Vt TLC ERV FRC RV RV Volume of air remaining in the lungs at the end of a normal expiration Cannot be measured with a simple spirometer Normal 2400 ml Decreased with restrictive and increased with obstructive FRC = ERV + RV, or FRC=TLC-IC 9 Vital Capacity (VC) IRV IC VC Vt TLC ERV FRC RV RV Volume of air that can be exhaled from the lungs after a maximum inspiration Normal=4,800 ml FVC: when VC exhaled forcefully SVC: when VC is exhaled slowly-copd VC = IRV + TV + ERV 10 5

6 Total Lung Capacity (TLC) IRV IC VC TV TLC ERV FRC RV RV Volume of air in the lungs after a maximum inspiration Normal=6000 ml Decreased with restrictive and increased obstructive TLC = IRV + VT + ERV + RV, or TLC=IC+FRC, or TLC=VC+RV 11 Normal Flow Volume Loop 12 6

7 Acceptability Criteria At least (3) acceptable maneuvers: 1. Good start of test 2. No hesita&on or coughing for the 1 st second 3. FVC dura&on of (6) seconds with (1) second plateau (< 7years old (3) second dura&on with.5 second plateau) 4. No valsalva maneuver 5. Maximal effort apparent- FIVC

8 Repeatability Criteria Repeatability criteria determines need for addi&onal efforts Minimum of (3) and maximum of (8) awempts - Largest and 2 nd largest FVC must be within 150 ml (0.150 L) - Largest and 2 nd largest FEV1 must be within 150 ml (0.150 L) 15 Repor&ng Standards Largest FVC obtained from all acceptable efforts should be reported Largest FEV 1 obtained from all acceptable trials should be reported Other values should come from the maneuver with the largest sum of FVC & FEV 1 PEF should be the largest value obtained from at least (3) acceptable maneuvers 16 8

9 Repor&ng Standards Trial 1 Trial 2 Trial 3 Best Test FVC FEV FEV1/FVC% FEF PEF Best Test: FVC from Trial #3, FEV1 from Trial #1, Other values from trial # 3. Trail #3 has the highest sum of FVC and FEVI. 17 Race Adjustments Race is an important consideration in evaluating pulmonary function data When compared with Caucasians of European decent other races usually present with: -smaller static volumes -lower forced expiratory flow rates -Similar FEV 1 /FVC ratios 18 9

10 Obstruc&ve Disorders Characterized by a limitation of expiratory airflow Examples: Asthma, COPD Decreased: FEV 1, FEF 25-75, FEV 1 /FVC ratio <80% Increased or Normal: TLC If SVC is greater than FVC suspect obstructive disease. Differences >5% indicate poor effort 19 Asthma and Flow Volume Loops Peak expiratory flow reduced so maximum height of the loop is reduced Airflow reduces rapidly with the reduction in the lung volumes because the airways narrow and the loop becomes concave Concavity may be the indicator of airflow obstruction and may present before the change in FEV 1 or FEV 1 /FVC

11 Reversibility Improvement in FEV 1 12% and 200 ml in repeating spirometry 15 minutes post bronchodilator therapy Reversibility is a characteristic feature of Asthma In chronic asthma there may be only partial reversibility of the airflow obstruction COPD the airflow is irreversible although some cases show some improvement (<12 % improvement) Bronchial Provoca%on Tes%ng A. Typically, administra&on of methacholine or histamine to evaluate airway hyperreac&vity. B. Test posi&ve if 20% reduc&on in FEV1. C. Methacholine dose required = PD 20% D. Bronchodilators held prior to tes&ng: E. Methacholine administered via neb or dosimeter 22 11

12 PFT Evalua&on FEF25%-75%: Volume of air expelled from the lungs during the middle half of the forced vital capacity test. Diffusing Capacity (DLCO): -Normal value 25 ml co/min/mmhg (STPD) -Normal in asthma and decreased in Emphysema PFT I PFT Evaluation FEV1/FVC Ratio Calculation: (FEV1/ FVC) x 100 Normal varies with age: Age <19 (8-19) <39 (20-39) <59 (40-59) <80 (60-80) Normal 85% 80% 75% 70% 24 12

13 Important Lab Values Chloride sweat testing: -Used to rule out cystic fibrosis Eosinophils: (cells/ mcl): - Play a prominent role in late phase asthmatic reactions -<350 cells normal ->350 cells indicate allergic reactions (asthma) Immunoglobins/Antibodies: -Immune system produces in response to presence of bacteria, viruses or foreign matter (pollen) -IgE is key in asthma and other allergic reactions Skin testing and allergy diagnosis -Done to identify causative allergens - Scratch or Prick test -After allergen identified, immunotherapy may begin (except for food allergen) 25 Complete Blood Count (CBC) CBC is usually normal in asthma. Values: a. RBC (million cells/mcl): -Female: Male: b. Hemoglobin (gm/dl): -Female: Male: c. Hematocrit (percent): -Female: Male: d. WBC (cells/mcl): -5,000 to 10,000 -Decreased with viral infections -Increased with bacterial infections 26 13

14 Four Primary Signs/Symptoms of Asthma Wheezing: Hallmark of asthma but may be caused by other including VCD, aspiration, bronchiolits, pneumonia, CF, heart disease, etc. Silent asthma may indicate serious threat Coughing: May be the only sign in children Chest tightness: Due to air not being completely exhaled prior to next breath SOB: Due to narrow airways 27 Palpa&on, Percussion, Ausculta&on CXR Palpa%on Heart Rate Determina&on Tac&le Fremitus Chest Mo&on Symmetry Percussion Resonance Flatness Dullness Tympany Hyperresonance 28 14

15 Ausculta&on/CXR Breath Sounds: Vesicular Wheezing Rales/Rhonchi Stridor Absent Breath Sounds CXR: FlaWened diaphragm Patchy infiltrates Bronchial wall markings 29 Dyspnea Grades Grade I Grade II Grade III Grade IV Grade V normal, usual exer&on breathlessness going up hills or stairs dyspnea while walking a normal speed dyspnea walking slowly for short distances dyspnea at rest 30 15

16 Ac&vity of Daily Living (ADL) Assessment ADLs are rou&ne tasks like: - bathing - brushing hair - brushing teeth - gekng dressed - ea&ng, etc ADL assessment used to determine: - home care requirement - nursing home admission - insurance - etc Social Support must be evaluated: - Loca&on of family, friends - Financial resources 31 Breathing Exercises Pursed Lip Breathing 1. Relax neck and shoulders 2. Inhale through nose for 2-3 seconds 3. Purse lips and exhale slowly 4. Exhala&on for 2-6 seconds Diaphragma%c Breathing 1. Lie flat on back with pillow under knees 2. One hand on upper chest and the other below the rib cage 3. Breath in through nose 4. Hand on stomach should raise while hand over chest s&ll 5. Contract stomach muscles and exhale though pursed lips 6. Hand over stomach should move inward, chest s&ll 32 16

17 Diaphragma%c Breathing Hand on stomach should raise while hand over chest is s&ll 33 Normal Arterial Blood Gases PaC02 Pa02 Sa02 ph HC Torr Torr 95-98% meq/l -Normal -Alkalosis -Acidosis 34 17

18 Classifica&on of Asthma: Assessment Six areas to be assessed for appropriate classifica&on: 1. Ac&vity level 2. Lung func&on 3. Symptoms 4. Awakening at night 5. Bronchodilator use (short ac&ng) 6. Risk 35 Classification Impairment <4 Years 5-11 Years 12 Year to Adult Intermittent 1. Activity level 1. No Limitation 1. No Limitation 1. No Limitation 2. FEV1 >80%, 2. FEV1 >80%, 2. Lung function 2. N/A FEV1/FVC >85% FEV1/FVC normal 3. Symptoms 3. < 2 days /week 3. < 2 days /week 3. < 2 days /week 4. Awakening at night 5. Bronchodilator use (short acting) 6. Risk 4. None 5. < 2 days /week 6. < 1 annually 4. < 2 night/month 5. < 2 days /week 6. < 1 annually 4. < 2 night/month 5. < 2 days /week 6. < 1 annually Mild Persistent 1. Activity level 2. Lung function 3. Symptoms 1. Minor Limitation 2. N/A 3. > 3 days /week 1. Minor Limitation 2. FEV1 >80%, FEV1/FVC >80% 3. > 3 days /week 1. Minor Limitation 2. FEV1 >80%, FEV1/FVC normal 3. > 3 days /week 4. Awakening at night 5. Bronchodilator use (short acting) 6. Risk 4. >1 night/month 5. > 3 days /week 6. >2 in 6 months 4. > 3 night/month 5. > 3 days /week 6. >2 annually 4. >3 Nights/month 5. > 3 days /week 6. >2 annually Moderate Persistent 1. Activity level 2. Lung function 3. Symptoms 1. Some Limitation 2. N/A 3. Daily 1. Some Limitation 2. FEVI 60-80%, FEVI/FVC 75-80% 3. Daily 1. Some Limitation 2. FEVI 60-80%, FEVI/FVC reduced 5% 3. Daily 4. Awakening at night 5. Bronchodilator use (short acting) 6. Risk 4. > 3 nights/month 5. Daily 6. >2 in 6 months 4. > 2 nights a week 5. Daily 6. > 3 annually 4. > 2 nights a week 5. Daily 6. > 3 annually Severe Persistent 1. Activity level 2. Lung function 3. Symptoms 1. Extreme Limit 2. N/A 3. All day 1. Extreme Limit 2. <FEVI 60%, FEVI/FVC < 75 % 3. All day 1. Extreme Limit 2. <FEVI 60 %, FEVI/FVC reduced >5% 3. All day 4. Awakening at night 5. Bronchodilator use (short acting) 6. Risk 4. > 1 night/week 5. All day 6. >2 in 6 months 4. All week 5. All day 6. > 3 annually 4. All week 5. All day 6. > 3 annually 36 18

19 Test Your Applica&on Knowledge! Trial #1 Trial# 2 Trial #3 FVC PEFR FEV FEF From which of these trials would you select the FEF 25-75? 2. Which of these trials may represent poor effort? 37 Do you remember? 1. What does the acronym Al- SABR stand for? 2. A patient with a FEV1 of 60-80% is classified as. 3. A patient who awakens > 2 night per week is classified as. 4. A patient who uses their SABA < 2 days per week is classified as. 5. A patient with extremely limited activity levels is classified as

20 39 20