The Classic Dichotomy. COPD- an attempt to differentiate the patient with moderate to severe emphysema (pink puffer) from the patient with chronic bronchitis (blue bloater).
Pulmonology
Edited by Charles L. Fishman, MD
Contributor – Rich Strongwater, MD
The pink puffer vs blue bloater distinction may be less useful given the overlap of chronic bronchitis in both groups (emphysema vs non-emphysema) and the non-distinct timeline of hypoxia in both groups. BMI does seem to be lower in the emphysema group. While the pink puffer and blue bloater classifications offer insights into COPD presentations, a deeper understanding of each patient's unique characteristics is crucial for effective management and treatment.
The Pink Puffer
Although these terms may seem out of date and politically incorrect they were an attempt to differentiate the patient with moderate to severe emphysema from the patient with chronic bronchitis.
The term “pink puffer” is colloquially used to describe the “typical” presentation of a patient with emphysema, in contrast to the “typical” patient with chronic bronchitis, who has been described as a “blue bloater.” Patients with predominant emphysema will respond to dyspnea by hyperventilating, and will for a time be able to maintain oxygenation and remain “pink.”
Emphysema Causes and Risk Factors
In emphysema, alveoli are lost, and the airways lose elasticity, leading to air trapping within the respiratory units, making exhalation more difficult. Oxygenation can be maintained by increasing minute volume (by increasing their breathing rate). Pursed lip breathing will help to increase the pressure within the airways and prevent collapse.
Pink Puffer Signs and Symptoms
Pink puffers often exhibit a thin body habitus, pursed lips with breathing, barrel chest, increased work of breathing, and rarely have cyanosis. They have prolonged expiration time, and may speak in short sentences. As emphysema and respiratory failure worsen, hypoxemia and loss of “pink” color can result.
The Blue Bloater
The term “blue bloater” is colloquially used to describe the “typical” presentation of a patient with chronic bronchitis, in contrast to the “typical” patient with emphysema, who has been described as a “pink puffer.” Patients with moderate chronic bronchitis are more likely to have hypoxemia compared to patients with moderate emphysema, and thus can have cyanosis and appear “blue.”
Chronic Bronchitis Causes and Risk Factors
In chronic bronchitis, there is increased mucous production, along with damage to airway epithelium. Gas exchange is disturbed, leading to a mismatch between ventilation and perfusion, and hypoxemia, hypercapnia and respiratory acidosis. This eventually leads to pulmonary vasoconstriction and right heart failure. It should be noted that severe emphysema can also cause respiratory failure, and that emphysema and chronic bronchitis are often found in the same patient.
Blue Bloater Signs and Symptoms
Blue bloaters have chronic productive cough, cyanosis, and peripheral edema (due to right heart failure). They will often appear plethoric (with facial swelling and redness or darkening of the face) and obese.
The Classic Dichotomy Emphysema vs Chronic Bronchitis
Table: Comparison between emphysema and chronic bronchitis
| Emphysema | Chronic bronchitis |
Definition | Pathological: alveolar parenchymal destruction and irreversible airspace dilatation | Clinical: Productive cough on most days for > 3 months a year for > 2 years. |
Pathogenesis | Imbalance between proteases and anti-proteases leads to destruction of lung parenchyma | Airway irritation leading to mucus gland hypertrophy/hyperplasia, mucus overproduction, and small airway clogging |
Pathophysiology |
|
|
Clinical features | "Pink puffer"
| "Blue bloater"
|
Adapted from Ni, A, ed. "Block B: Respiration" from "Osler Notes". McGill Medical Students Society, 2019.
Conclusion: Chronic Obstructive Pulmonary Disease (COPD)
The blue bloater vs pink puffer distinction may be less useful given the overlap of chronic bronchitis in both groups (emphysema vs non-emphysema) and the non-distinct timeline of hypoxia in both groups.
Chest CT scan along with formal pulmonary function testing may be the best way to differentiate and characterize your COPD patient. Changes on CT scan in pulmonary emphysema results from dilatation of airspaces and destruction of airspace walls distal to terminal bronchioles. This is seen as low attenuation areas on the CT with vascular distortion and thinning.
High-resolution computed tomography (HRCT) may discover abnormal findings associated with emphysema earlier and may also give a better view of pathology progression.
Chronic bronchitis exists in both groups thereby explaining why patients with “asthma-overlap” exist in both groups. Nevertheless, COPD-asthma overlap is more common in non-emphysematous COPD, as is bronchodilator responsiveness.
One third of patients with COPD may have eosinophilic airway inflammation and treatment directed at eosinophilia may be warranted. More studies regarding eosinophila as a potentially useful biomarker in the treatment of COPD are needed.
BMI does seem to be low in the emphysema group. BMI is higher in the chronic bronchitis group. This along with chronic inflammation may explain the association with non-emphysema COPD and diabetes or metabolic syndrome.
While the pink puffer and blue bloater classifications offer insights into COPD presentations, a deeper understanding of each patient's unique characteristics is crucial for effective management and treatment.
References
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Mirza S, Clay RD, Koslow MA, Scanlon PD. COPD Guidelines: A Review of the 2018 GOLD Report. Mayo Clin Proc. 2018 Oct. 93 (10):1488-1502.
Hersh C, Make B, Lynch D, et al. Non-emphysematous chronic obstructive pulmonary disease is associated with diabetes mellitus. BMC Pulm Med. 2014; 14: 164. Published online 2014 Oct 24. doi: 10.1186/1471-2466-14-164
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initially published January 2023