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

Normal Spirogram All parameters are normal Normal shape in VT and FV loop

A. Normal: both the FVC and the FEV1/VC ratio are normal. “Knee”

Obstructive pattern

Obstructive pattern

The severity of the abnormality is graded: - % Pred FEV1 > 100 = May be a physiological variant - % Pred FEV1 < 80 and > 70 Mild - % Pred FEV1 < 70 and > 60 Moderate severe -% Pred FEV1 < 60 and > 50 Moderately - % Pred FEV1 < 50 and > 35 Severe - % Pred FEV1 < 35 Very severe

Severe obstructive pattern

Restrictive pattern

Restrictive pattern

The severity of the abnormality might be graded as follows: - % Pred FVC < LLN and > 70 mild - % Pred FVC < 70 and > 60 Moderate -% Pred FVC < 60 and > 50 Moderately severe -% Pred FVC < 50 and > 34 Severe - % Pred FVC < 34 Very severe

Mixed pattern

Small airway obstruction

Early small airway obx FV curve :upward concavity FVC, FEV1, FEV1/FVC :NL  FEF 25-75 ??? ATS states that FEF25-75% should not be used to diagnose small airway disease or to assess respiratory impairment

Probably normal

Isolated decrease in FEF25-75 Isolated decrease in FEV1/FVC

Probably normal spirogram Only  FEF 25-75 No small airway disease (ATS) Only  FEV1/FVC FEV1> 100% Probably Normal FVC>100%

Nonspecific ventilatory pattern Similar to restrictive pattern Normal TLC, RV & DLco Obesity Asthma COPD Normal variant

Upper airway obx

Upper airway obstruction pattern

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 General health Occupational health screening

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 time NIOSH : (0.85 .initial FEV1 or FVC) – (number of yr . 0.025) FVC FEV1 male female 30 ml/yr 25 ml/yr (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 for follow-up results if: 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) FEV1, FVC or FEV1/FVC < LLN at any time >10% decline between pre and post shift screening

Case 1 A 71 yrs male Height :175 ,weight :88 FVC:45% FEV1: 31% FEV1/ FVC :53% FEF25-75 :15% TLC :142% very severe obx

Case 2 A 36 yrs female Height :162 ,weight :83 FVC:89% FEV1: 94% FEV1/ FVC :89% FEF25-75 :131% TLC :92% normal

Case 3 A 29 yrs female Height :165 ,weight :129 FVC:78% FEV1: 79% FEV1/ FVC :86% FEF25-75 :85% TLC :82% non specific ventilatory

Case 4 A 43 yrs female Height :61,weight :167 FVC:33% FEV1: 17% FEV1/ FVC :42% TLC :114% variable inthratoracic obx

Case 5 A 30 yrs male Height :186,weight :68 FVC:19% FEV1: 21% FEV1/ FVC :93% FEF25-75% :48% TLC :28% very severe restriction

Case 6 A 30 yrs male Height :175 ,weight :70 FVC: 88% FEV1: 69% FEV1/ FVC :66% FEF25-75 :38% VEXT : 90 moderate obx

Case 7 A 29 yrs male Height :179 ,weight :83 FVC: 95% FEV1: 84% FEV1/ FVC :67% FEF25-75 :51% VEXT : 120 Mild obx

Case 8 A 26 yrs male Height :177 ,weight :67 FVC: 97% FEV1: 77% FEV1/ FVC :66% FEF25-75 :48% VEXT : 60 mild obx

Post bronchodilator spirometry (reversibility testing) Short-acting inhaled drugs should not be used within 4h of testing Long-acting should be stopped for 12h prior test Smoking should be avoided for ≥ 1h Salbutamol 400 µg (4 puffs) at 30s intervals → ≥ 10 min and up to 15 min Ipratropium bromide 160 µg (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 male Height :170 ,weight :82 FVC:80% FEV1: 70% FEV1/ FVC :69% FEF25-75 :50%

pre post %change FVC 4 4.26 +7 FEV1 2.91 3.32 +14 FEV1/ FVC 72.8 77.9 +7 FEF25-75 2.32 3.09 +31

Case A 70 yrs male, Height :172 ,weight :65 pre %pred post %chg FVC 3.13 83 3.52 +12 FEV1 2.02 70 2.49 +23 FEV1/ FVC 64.5

Case A 28 yrs male , Height :192 ,weight :92 pre %pred post %chg FVC 5.68 95 5.81 +2 FEV1 4.02 81 4.28 +6 FEV1/ FVC 68.2

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