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Interpretation
Normal Spirometry Obstructive pattern Restrictive pattern Mixed pattern Small airway obstruction Non-specific ventilatory pattern Probably normal pattern Upper airway obstruction pattern Neuromuscular diseases
A. Normal:A. Normal: both the FVC and the both the FVC and the FEVFEV11/VC ratio are normal./VC ratio are normal.
““KneeKnee””
The severity of the abnormality is graded:The severity of the abnormality is graded:
- % Pred FEV- % Pred FEV11 > 100 > 100 = = May be a physiological May be a physiological variantvariant
- % Pred FEV- % Pred FEV11 < 80 and > 70 < 80 and > 70 MildMild
- % Pred FEV- % Pred FEV11 < 70 and > 60 < 70 and > 60 ModerateModerate severesevere
--% Pred FEV% Pred FEV11 < 60 and > 50 < 60 and > 50 ModeratelyModerately
- % Pred FEV- % Pred FEV11 < 50 and > 35 < 50 and > 35 SevereSevere
- % Pred FEV- % Pred FEV11 < 35 < 35 Very severeVery severe
The severity of the abnormality might be The severity of the abnormality might be graded as follows:graded as follows:
-- % Pred FVC < LLN and > 70 % Pred FVC < LLN and > 70 mildmild- - % Pred FVC < 70 and > 60% Pred FVC < 70 and > 60 ModerateModerate--% Pred FVC < 60 and > 50% Pred FVC < 60 and > 50 ModeratelyModerately
severesevere--% Pred FVC < 50 and > 34% Pred FVC < 50 and > 34 SevereSevere- - % Pred FVC < 34 % Pred FVC < 34 Very severeVery severe
Early small airway obxEarly small airway obx
FV curve :upward concavityFV curve :upward concavity
FVC, FEV1, FEV1/FVC :NLFVC, FEV1, FEV1/FVC :NL FEF 25-75 ???FEF 25-75 ??? ATS states that FEF25-75% should not be used to
diagnose small airway disease or to assess respiratory impairment
Probably normal spirogramProbably normal spirogram
Only Only FEF 25-75 FEF 25-75 No small airway disease (ATS)No small airway disease (ATS)
Only Only FEV1/FVC FEV1/FVC
FEV1> 100% Probably NormalFEV1> 100% Probably Normal
FVC>100%FVC>100%
Nonspecific ventilatory pattern
Similar to restrictive pattern
Normal TLC, RV & DLco
Obesity Asthma COPD Normal variant
Indications for referral
FEV1/FVC less than %75 and FEV1 less than %80 FEV1/FVC more than %75 and FVC less than %80 Significant reduction across time Pulmonary symptoms or signs even with normal spirogram
Screening Spirometry in General Healthy Population
Baseline spirogram in all at 20-25 Periodic spirogram depends on risk factors
such as smoking each 1-5 yrs.
Occupational screening spirogram In certain occupational exposures
Asbestos, silica, cadmium, cotton, coal, beryllium, wood dust,….
Usually each 1-2 yrs
Comparison of periodic spirogram Significant change in FEV1 or FVC
Cross-shift Week-to-week Year-to-year
Definition
Considerations in periodic spirogram Using:
Similar reference values Similar patient position Similar time Standard spirometer Standard technique
Change in spirometric indices over timeChange in spirometric indices over time
malemale femalefemale malemale femalefemale
30 ml/yr30 ml/yr 25 ml/yr25 ml/yr 25 ml/yr25 ml/yr 25 ml/yr25 ml/yr
FEV1FEV1 FVCFVC
NIOSHNIOSH : :
(0.85 .initial FEV1 or FVC) – (number of yr . 0.025)(0.85 .initial FEV1 or FVC) – (number of yr . 0.025)
(value on time 1 – value on time 2 / value on time 1) × 100
In an ongoing annual surveillance of asbestos workers, a 24 year old woman is found to have an FVC of 3.59 liters. Her previous FVC was 4.17 liters. What is your interpretation?
Absolute change: 4.17-3.59 = .58 liters She showed a loss of .58 liters.
Percent change: ((4.17-3.59)/4.17) x 100 = 13.9% She showed a loss of 13.9% in her FVC.
Further investigation recommended Further investigation recommended
for follow-up results iffor follow-up results if::
1. Decline in FEV1 or FVC > 15% in longitudinal screening. If the period is > 5 years, adjust for the decline due to aging (25 ml/year)
2. FEV1, FVC or FEV1/FVC < LLN at any time
3. >10% decline between pre and post shift screening
Case 1Case 1
A 71 yrs maleA 71 yrs male HeightHeight :175 , :175 ,weightweight :88 :88 FVC:45%FVC:45% FEV1: 31%FEV1: 31% FEV1/ FVC :53%FEV1/ FVC :53% FEF25-75 :15%FEF25-75 :15% TLC :142%TLC :142% very severe obxvery severe obx
Case 2Case 2
A 36 yrs femaleA 36 yrs female
HeightHeight :162 , :162 ,weightweight :83 :83
FVC:89%FVC:89%
FEV1: 94%FEV1: 94%
FEV1/ FVC :89%FEV1/ FVC :89%
FEF25-75 :131%FEF25-75 :131%
TLC :92%TLC :92%
normalnormal
Case 3Case 3
A 29 yrs femaleA 29 yrs female HeightHeight :165 , :165 ,weightweight :129 :129 FVC:78%FVC:78% FEV1: 79%FEV1: 79% FEV1/ FVC :86%FEV1/ FVC :86% FEF25-75 :85%FEF25-75 :85% TLC :82%TLC :82% non specific ventilatorynon specific ventilatory
Case 4Case 4
A 43 yrs femaleA 43 yrs female HeightHeight :61, :61,weightweight :167 :167 FVC:33%FVC:33% FEV1: 17%FEV1: 17% FEV1/ FVC :42%FEV1/ FVC :42% TLC :114%TLC :114% variable inthratoracicvariable inthratoracic obxobx
Case 5Case 5
A 30 yrs maleA 30 yrs male HeightHeight :186, :186,weightweight :68 :68 FVC:19%FVC:19% FEV1: 21%FEV1: 21% FEV1/ FVC :93%FEV1/ FVC :93% FEF25-75% :48%FEF25-75% :48% TLC :28%TLC :28% very severe restrictionvery severe restriction
Case 6Case 6
A 30 yrs maleA 30 yrs male
HeightHeight :175 , :175 ,weightweight :70 :70
FVC: 88%FVC: 88%
FEV1: 69%FEV1: 69%
FEV1/ FVC :66%FEV1/ FVC :66%
FEF25-75 :38%FEF25-75 :38%
VEXT : 90VEXT : 90
moderate obxmoderate obx
Case 7Case 7
A 29 yrs maleA 29 yrs male
HeightHeight :179 , :179 ,weightweight :83 :83
FVC: 95%FVC: 95%
FEV1: 84%FEV1: 84%
FEV1/ FVC :67%FEV1/ FVC :67%
FEF25-75 :51%FEF25-75 :51%
VEXT : 120VEXT : 120
Mild obxMild obx
Case 8Case 8
A 26 yrs maleA 26 yrs male
HeightHeight :177 , :177 ,weightweight :67 :67
FVC: 97%FVC: 97%
FEV1: 77%FEV1: 77%
FEV1/ FVC :66%FEV1/ FVC :66%
FEF25-75 :48%FEF25-75 :48%
VEXT : 60VEXT : 60
mild obxmild obx
Post bronchodilator spirometry(reversibility testing)
Short-acting inhaled drugs should not be used Short-acting inhaled drugs should not be used within within 4h4h of testing of testing
Long-acting should be stopped for Long-acting should be stopped for 12h12h prior test prior test Smoking should be avoided for Smoking should be avoided for ≥ 1h≥ 1h Salbutamol Salbutamol 400 µg400 µg (4 puffs) at 30 (4 puffs) at 30s intervalss intervals → ≥ → ≥
10 min and up to 15 min10 min and up to 15 min Ipratropium bromide Ipratropium bromide 160 µg160 µg (4 puffs)→30 min (4 puffs)→30 min
later
Positive reversibility testing
Percent change from baseline & absolute change in FEV1 and/or FVC :
>12% AND 200 CC
Other criteria include:
At least 20% increase in FEF25-75%
A 24 yrs maleA 24 yrs male HeightHeight :170 , :170 ,weightweight :82 :82
FVC:80%FVC:80% FEV1: 70%FEV1: 70% FEV1/ FVC :69%FEV1/ FVC :69% FEF25-75 :50%FEF25-75 :50%
pre post %change pre post %change
FVC 4 4.26 +7FVC 4 4.26 +7
FEV1 2.91 3.32 +14 FEV1 2.91 3.32 +14
FEV1/ FVC 72.8 77.9 +7 FEV1/ FVC 72.8 77.9 +7
FEF25-75 2.32 3.09 +31 FEF25-75 2.32 3.09 +31
Case Case
A 70 yrs male, A 70 yrs male, HeightHeight :172 , :172 ,weightweight :65 :65
pre %pred post %chgpre %pred post %chg
FVC 3.13 83 3.52 +12 FVC 3.13 83 3.52 +12
FEV1 2.02 70 2.49 +23FEV1 2.02 70 2.49 +23
FEV1/ FVC 64.5FEV1/ FVC 64.5
Case Case
A 28 yrs male , A 28 yrs male , HeightHeight :192 , :192 ,weightweight :92 :92
pre %pred post %chgpre %pred post %chg
FVC 5.68 95 5.81 +2FVC 5.68 95 5.81 +2
FEV1 4.02 81 4.28 +6FEV1 4.02 81 4.28 +6
FEV1/ FVC 68.2FEV1/ FVC 68.2