Obstructive Diseases + Discussion

what is the defining finding of obstructive diseases on a PFT

FEV₁/FVC ratio is reduced

how does an obstructive flow-volume loop look like

• “scooped out” over the latter portion of exhalation due to different lung units emptying at different rates

• reduced peak expiratory flow rate compared to the predicted value

what are the two major diseases that are obstructive

• asthma

• COPD

what is asthma

variable and recurring symptoms of dyspnea, airflow obstruction and airway; show reversible airflow obstruction

what are the three common findings in asthma

• secretions in the airway- mucous

• smooth muscle hypertrophy- constriction

• inflammation- edema

what are the three main categories in tx asthma

• medications

• eliminate or control triggers

• identify other stressors

how is COPD characterized

• chronic respiratory symptoms

• airflow obstruction

• incomplete reversibility

why is COPD a syndrome

it is a combination of diseases that make it up

what is the major cause of COPD in the USA

smoking

what are the two disease that make up the syndrome COPD

• emphysema

• chronic bronchitis

what is emphysema

destruction of the alveolar walls w/o fibrosis resulting in permanent enlargement of the distal airspaces

emphysema is an irreversible destructive process, what two mechanisms can lead to this

• dissolution of the alveolar wall and enlargement of alveolar spaces

• loss of pulmonary capillaries surrounding the alveoli

what is the key feature of emphysema

enlarged alveolar spaces

how to confirm the identity of emphysema

based on radiologic finishings/histologic; but this analysis would only be done on a post-mortem exam or following lung transplant

what is chronic bronchitis

bronchial inflammation that produces a chronic productive cough for three month in each of 2 successive years w no other explanation

chronic bronchitis results i airway obstruction due to what three combined effects

• inc airway secretions

• glandular hypertrophy

• bronchial wall edema

what is the key finding of chronic bronchitis

based on history provided by pt

what is the key feature of chronic bronchitis

productive cough for >/= 3 mo out of a yr for >/= 2 yrs

COPD is caused by noxious/particle inhalation, most notably…

cigarette smoke

how is airflow obstructed in COPD

• loss of radial traction due to emphysematous changes in lung

• dec tethering effect of parenchyma to airway (leads to small diameter)

• dec driving pressure on exhalation→ dec airflow

why do we see and inc in FRC in a person w COPD

individual airspaces are larger which will inc air trapping, emphysematous changes diminish the recoil forces of the lung → inc FRC

what are the three categories in tx COPD

• pulmonary rehabilitation

• long-term oxygen therapy

• smoking cessation

what medication should you avoid w a pt w COPD

no inhaled corticosteroids bc the risk of fungal infection (no cilia that would be able to remove these invaders)

in a pt w COPD, how do they present

exertional dyspnea, chronic cough, insidious sputum production, and can present w dyspnea at rest and/or wheezing

is asthma or COPD a progressive disease

COPD- chronic condition

what is the age onset of asthma

younger pt but can occur at any age

what is the age onset of COPD

milder to older ages

is asthma more pronounced in the inhalation or exhalation phase

exhalation

what are common triggers of asthma

allergens, smoke, medications, exercise, or a URI

when thinking of drugs as one of the triggers for asthma, what medication do you want to be sure that you don’t px pts and why

NSAIDs; can cause bronchoconstriction

what is the first line of medications for asthma

inhaled short-acting beta 2 agonists; as severity inc, inhaled corticosteroids are added

COPD is a syndrome of “ “ by the Global Initiative for Chronic Obstructive Disease

pulmonary symptoms characterized by airflow limitation due to airway and alveolar limitations and usually caused by exposure to noxious particles or gases

what is Alpha-1 Antitrypsin (AAT) deficiency

an uncommon inherited form of COPD that is not caused by smoking and can present in younger ages

mechanism of AAT deficiency in the body

individual lacks AAT which inhibits neutrophil elastase → excess neutrophil elastase results in destruction of the elastic component of the lung parenchyma → emphysema development

main difference of AAT deficiency vs COPD

AAT destruction happens in the bases of the lungs rather than diffuse destruction as in typical COPD

people w AAT deficiency predominately have _______________ symptoms but they also have ________ problems

emphysematous; liver

what type of liver problems can a person w AAT deficiency have

liver inflammation (hepatitis), liver fibrosis (cirrhosis), liver cancer (hepatocellular carcinoma)

what is cystic fibrosis

an AR inherited condition that results in a loss of funx of cystic fibrosis transmembrane regulator (CFTR) which is encoded on the long arm of chromosome 7; pts have severe pulmonary symptoms

what anti-anxiety medication is recommended w pts that have COPD, are there precautions?

low dose of oral diazepam; these can dec the respiratory drive so it must be used w caution

what anti-anxiety intervention is not recommended in a pt that has COPD, why

nitrous oxide; is insoluble in the blood so it will quickly move to the airspaces of the lung and will ultimately inc pressure in the bullae, can lead to lung rupture and pneumothroax

why should you not inc supplemental oxygen in a person w COPD

can lead to hypercapnia

what is hypercapnia

high PCO₂, this can cause dec consciousness and in intracranial pressure leading to seizures and coma

to minimize an acute asthma attack, we want to avoid odorants such as…

methyl methacrylate