1 emphysema. 2 what is emphysema? permanent abnormal enlargement of the acini (acinius, latin for...

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Emphysema

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What is Emphysema?

Permanent abnormal enlargement of the acini(acinius, Latin for “berry”) (MedicineNet, 1999)

Destruction of alveolar walls without obvious fibrosis(McCance & Huether, 2006)

Specifically, two things combined:

Image from www.nucleusinc.com

(as opposed to something like Asbestosis: http://en.wikipedia.org/wiki/Asbestosis)

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Two kinds of emphysema

Primary emphysema1-2% of casesInherited lack of alpha-1 antitrypsin, a

protective protein (inhibits neutrophil elastase)

Secondary emphysemaAlso caused by inability to inhibit

proteolytic enzymes in the lungsFrom inhaled toxins (e.g., cigarette smoke)20% of smokers at risk (McCance & Huether, 2006)

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Secondary Emphysema: Pathophysiology

Toxins (smoke) cause inflammationInfiltration of neutrophils, macrophages

and lymphocytesInflammatory cytokines increase

protease activity, inhibiting normal antiprotease activity (antitrypsin)

Alveoli are destroyed because elastin is being broken down by proteases(McCance & Huether, 2006)

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Acinius Normal vs. Emphysema

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Emphysema & Normal Alveoli

• Loss of septa

• Loss of capillary beds

• Hyperinflation

• Loss of elastic recoil & collapse of alveoli

• Increased residual volume

• Decreased diffusion (lower SA/Volume )

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Bullous Emphesyma

“Bullae are large dilated airspaces that bulge out from beneath the pleura.”

[Image and quote from http://medlib.med.utah.edu/WebPath/LUNGHTML/LUNG056.html]

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Centriacinar (centrilobar) Emphysema

Respiratory bronchioles in proximal portion of acinus are lost

Alveoli distal to terminal bronchiole intact

Occurs in smokers with chronic bronchitis

Usually in upper lobes

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Emphysema: Clinical Manifestations

•Dyspnea•Wheezing is minimal•Barrel chest, often thin•Tachpynea with prolonged expiration•Pursed lip breathing•Tripod stance•Hypoxemia &/or hypercapnia•Chronic hypoventilation (later stage)•Not much coughing with little sputum

(Productive cough with infection)

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COPD: Chronic Bronchitis & Emphysema

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Barrel Chest: Increased Anterior/Posterior Diameter

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Radiograph: Emphysema, Pulmonary hypertension, Cardiomegaly

•Flattened diaphragm

•Hyperinflation

•Translucency of lung

•Hypertrophy of heart

(Hypoxia/ hypercapnea & damage = pulmonary vasoconstriction & hypertension. Later cor pulmonale)

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Clubbing of the Nails

A sign of chronic hypoxia

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Normal Spirograph

Emphysema Spirograph

FEV1/VC normally greater than 75%(per Walters presentation)

Decreased FEV1/VC

Total Lung Capacity normal or increased

RV increased