263 Spiro COPD Noon Conf 2025
263.1 Summary
- Spirometric Obstruction COPD Diagnosis
- Most COPD diagnoses are wrong.
- Misdiagnosis
- What is obstruction?
- Dichotomizing a continuous measure
- Over-diagnose the old, under-diagnose the young?
- Or < 0.7 if using GOLD
- Example 1
- Example 2
- Example 3
263.2 Slide outline
263.2.1 Slide 1
- Spirometric Obstruction COPD Diagnosis
- Brian Locke MD MSCI
- Assistant Professor of Research
- Department of Pulmonary and Critical Care
- Intermountain Medical Center
- Disclosures:
- Research support from the Intermountain Fund, American Thoracic Society, NIH
- Equity in theMTN.ai , time-series machine learning for patient monitoring ### Slide 2
- TODO: No text extracted from this slide. ### Slide 3
- Most COPD diagnoses are wrong.
- Misdiagnosed ### Slide 4
- Misdiagnosis ### Slide 5
- What is obstruction?
- Starling Resistor
- Flow-volume loop
- Effort-independent
- Spirogram ### Slide 6
- TODO: No text extracted from this slide. ### Slide 7
- Dichotomizing a continuous measure
- Obstruction FEV1/FVC < 0.70
- Obstruction FEV1/FVC < LLN
- for age, sex, height
- Not “<70% predicted”! ### Slide 8
- Over-diagnose the old, under-diagnose the young? ### Slide 9
- Or < 0.7 if using GOLD ### Slide 10
- Example 1
- 30-year-old male; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 3.5L
- 81.0%
- 3.36
- FEV1
- 2.75
- 68.5%
- 2.84
- FEV1/FVC
- 0.714
- 84.5%
- 0.74
- Obstruction (GOLD)?
- Obstruction (GLI)? ### Slide 11
- Example 1
- 30-year-old male; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 3.5L
- 81.0%
- 3.36
- FEV1
- 2.75
- 68.5%
- 2.84
- FEV1/FVC
- 0.714
- 84.5%
- 0.74
- Obstruction (GOLD)? No (above 0.7)
- Obstruction (GLI)? Yes (below 0.74) ### Slide 12
- Example 2
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 3.5L
- 116%
- 1.91
- FEV1
- 2.75
- 120%
- 1.42
- FEV1/FVC
- 0.714
- 92.3%
- 0.639
- Obstruction (GOLD)?
- Obstruction (GLI)? ### Slide 13
- Example 2
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 3.5L
- 116%
- 1.91
- FEV1
- 2.75
- 120%
- 1.42
- FEV1/FVC
- 0.714
- 92.3%
- 0.639
- Obstruction (GOLD)? No (Above 0.7)
- Obstruction (GLI)? No (Above 0.639) ### Slide 14
- Example 3
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 1.8L
- 65%
- 1.91
- FEV1
- 1.25
- 60%
- 1.42
- FEV1/FVC
- 0.69
- 89.7%
- 0.639
- Obstruction (GOLD)?
- Obstruction (GLI)? ### Slide 15
- Example 3
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 1.8L
- 65%
- 1.91
- FEV1
- 1.25
- 60%
- 1.42
- FEV1/FVC
- 0.69
- 89.7%
- 0.639
- Obstruction (GOLD)? Yes (below 0.7)
- Obstruction (GLI)? No (above 0.64)
- (has restriction, FVC < 1.91) ### Slide 16
- Post-Bronchodilator vs Bronchodilator Response
- BD-response (10%+) or not has NO ROLE IN DIAGNOSING COPD OR ASTHMA
- Not predictive of COPD vs Asthma
- Does portend worse trajectory ### Slide 17
- Example 4
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 1.8L
- 65%
- 1.91
- 2.0L
- 71%
- FEV1
- 1.25
- 60%
- 1.42
- 1.4L
- 67%
- 1.42L
- FEV1/FVC
- 0.69
- 89.7%
- 0.639
- 0.71
- 92%
- Post-BD Obstruction (GOLD)?
- Post-BD Obstruction (GLI)? ### Slide 18
- Example 4
- 80-year-old female; 5 ft 6
- Pre
- %Predicted
- LLN
- Post
- FVC
- 1.8L
- 65%
- 1.91
- 2.0L
- 71%
- FEV1
- 1.25
- 60%
- 1.42
- 1.4L
- 67%
- 1.42L
- FEV1/FVC
- 0.69
- 89.7%
- 0.639
- 0.71
- 92%
- Post-BD Obstruction (GOLD)? No
- Post-BD Obstruction (GLI)? No
- (has PRISM) ### Slide 19
- TODO: No text extracted from this slide. ### Slide 20
- Summary (Part 1)
- Obstruction occurs because after the initial burst, we don’t volitionally control our exhalation speed – depends on lung mechanics
- An FEV1/FVC that is too low defines obstruction
- The exact threshold is arbitrary, debatable
- Post-BD FEV1/FVC defines diagnoses, but BD response has no role in diagnosis. ### Slide 21
- What’s the weakest link? ### Slide 22
- Implication: impaired lung function doesn’t always cause dyspnea (on exertion)
- Warning: air hunger is extremely aversive; people will modify their behavior to avoid it and not realize they have excess dyspnea on exertion. ### Slide 23
- COPD: chronic bronchitis or emphysema
- Chronic Bronchitis
- COPD
- Emphysema
- Post-BD Airway Obstruction
- ??? ### Slide 24
- COPD: chronic bronchitis or emphysema
- Post-BD Airway Obstruction
- COPD
- Emphysema
- Chronic Bronchitis
- Chronic Bronchitis: cough with expectorated sputum on a regular basis for 3-months per year over a 2-year period in the absence of another condition that explains the symptoms.
- Emphysema: alveolar destruction that leads to loss of elastic recoil of the lung (slower emptying), reduced gas diffusing capacity.
- Emphysema without obstruction: ”Pre-COPD”
- COPD: Post-BD Airway Obstruction in the presence of irreversible damage ### Slide 25
- Scenario 1:
- 50F with prior smoking history (15 years) presents to clinic with shortness of breath limiting her exertion. PFTs show post-BD obstruction on PFTs. There is a positive BD response.
- What data can you gather to tell if the patient has COPD or Asthma? ### Slide 26
- Scenario 1:
- Comorbidities (eczema, allergic rhinitis, EoE/GERD)
- Presence (or absence) of detectable emphysema
- DLCO (often high in asthma, low in COPD)
- Day-to-day variation (esp with exposures)
- BD-response (10%+) or not has NO ROLE IN DIAGNOSING COPD OR ASTHMA
- Not predictive of COPD vs Asthma
- Does portend worse trajectory ### Slide 27
- Scenario 1:
- 65M current smoker presents w 7d of worsening shortness of breath and productive cough. No prior PFTs. Is this an acute exacerbation of COPD?
- In patients with hypercapnic respiratory failure… ### Slide 28
- TODO: No text extracted from this slide. ### Slide 29
- Questions?
- Email: brian.locke@imail.org
263.3 Learning objectives
- Spirometric Obstruction COPD Diagnosis
- Most COPD diagnoses are wrong.
- Misdiagnosis
- What is obstruction?
- Dichotomizing a continuous measure
263.4 Bottom line / summary
- Spirometric Obstruction COPD Diagnosis
- Most COPD diagnoses are wrong.
- Misdiagnosis
- What is obstruction?
- Dichotomizing a continuous measure
263.5 Approach
- TODO: Outline the initial assessment or decision point.
- TODO: Outline the next diagnostic or management step.
- TODO: Outline follow-up or escalation criteria.
263.6 Red flags / when to escalate
- TODO: List red flags that require urgent escalation.
263.7 Common pitfalls
- TODO: Capture common errors or missed steps.
263.8 References
TODO: Add landmark references or guideline citations.