Clinical Eval of Pts with Lung Disease Flashcards
Normal RR (Current)`
12-14
Kussmaul breathing
Rapid, large-volume breathing indicating intense stimulation of the respiratory center, seen in metabolic acidosis
Cheyne-Stokes respiration
a rhythmic waxing and waning of both rate and tidal volumes that includes regular periods of apnea. Seen in patients with end-stage LV failure, neurologic disease, in normal people sleeping at high altitude.
bronchial lung sounds over periphery suggest
consolidation
globally diminished breath sounds suggest
obstruction
What is the difference between fine and course crackles?
Fine crackles (<20ms) are gas bubbling through fluid and are heard in pneumonia, obstructive lung disease, and late pulm edema.
Digital clubbing suggests
Pulmonary: chronic infection, malignancy of lung/pleura, chronic interstitial fibrosis.
Does not occur in COPD or asthma.
Can also occur in cyanotic heart disease, infective endocarditits, cirrhosis, inflammatory bowel disease.
Hypertrophic pulmonary osteoarthropathy
a syndrome of digital clubbing, chronic proliferative periostitis of the long bones, and synovitis. Seen in same conditions as digital clubbing but is particularly common in bronchogenic carcinoma.
Cyanosis suggests
increased amount of deoxyhemoglobin in capillary blood. This can be due to hypoxemia, but not always. In polycythemia, cyanosis will occur even in very mild hypoxemia. In anemia, cyanosis will not occur, even in severe hypoxemia. Basically if you see cyanosis, get an arterial blood p02 or Hg sat.
Two ‘indirect’ measurements of pulmonary hypertension are
CVP (by JVP) and assessment of lower extremity edema.
Expected FEV1/FVC in obstructive disease
Expected to be low due to increased resistance (FEV1 is low, FVC is high).
List some obstructive diseases
COPD, Asthma, bronchiectasis, bronchiolitis, upper airway obstruction
Expected FEV1/FVC in restrictive disease
Normal to increased (largely due to reduced FVC).
How to diagnose restrictive disease:
Total lung capacity must be reduced. Reduced FVC is suggestive, but not diagnostic.
List some restrictive diseases
Pulmonary fibrosis, phrenic nerve injury (reduces diphragmatic contraction), diaphragm dysfunction, neuromuscular disease, pleural disease (eg pleural effusion, pleural restriction), lung resection.
When do you order diffusing capacity?
When you suspect diffuse infiltrative disease or emphysema
How is DL(CO) useful in evaluating an AIDS patient with cough?
It is highly sensitive (but not specific) for pneumocystis. A normal DL(co) is evidence against pneumocystis.
When is an arterial blood gas indicated?
When acid-base disturbance, hypoxemia, or hypercapnia (high CO2) is suspected
When is pulse Ox inaccurate?
Anemia, hemoglobinopathy, when pulsatile arterial flow is disrupted.
Bronchial provocation testing
Useful in diagnosing asthma in pts with normal spirometry. A nebulized bronchoconstrictor is given. If FEV1 falls by more than 20% at a dose of less than 16mg/mL, then the test is positive. Sensitivity is high (95%) specificity is 70%.
When is a rigid bronchoscopy indicated?
Massive bleeding, extraction of large obstructing objects, biopsy of tracheal or main stem bronchus tumors. Requires general anaesthesia (unlike flexible bronchoscopy).
Acute upper airway obstruction: causes
trauma, foreign body aspiration, laryngospasm, laryngeal edema, infections (epiglottitis), acute allergic laryngitis.
What is the strongest identifiable predisposing factor for the development of asthma?
Atopy (allergy)
Exercise-induced bronchoconstriction
Begins during or within 3 minutes of exercise ending, peaks within 10-15 minutes, and resolves within 60 minutes. A consequence of airway’s attempt to warm and humidify additional volumes.
Why are asthma symptoms worst at night?
Circadian variations in bronchomotor tone increase bronchial symptoms between 3 and 4 AM.
What is the most common lab abnormality in asthma?
respiratory alkalosis
First steps if you suspect asthma
Spirometry. Compare results before and after administration of bronchodilator. If FEV1 increases by 12% or more OR FVC increases by 15% or more after bronchodilator, this confirms asthma. A negative test does not rule it out though. If Spirometry and bronchodilator tests are negative, move on to bronchial provocation testing.
Peak expiratory flow
Useful in asthma management and can be measured with handheld device. Measure once in the morning before taking bronchodilator and once in the afternoon after taking bronchodilator. 20% or greater increase means therapy is adequate.
What else is on your DDx with asthma?
Upper airway disorders (eg vocal cord paralysis), COPD, systemic vasculitides, psych
Define “control” and “responsiveness” in asthma therapy
Control is the degree to which symptoms and activity limitations are minimized by therapy.
Responsiveness is the ease with which control is achieved with therapy.
