Pulmonary Medicine Flashcards
(130 cards)
Define dyspnea
- subjective experience of shortness of breath
- common from pulmonary and cardiac disease
Define tachypnea
- increased rate of breathing
>20 breaths/min
Define hyperpnea
- deep and rapid breathing
Define hyperventilation
- increased alveolar ventilation, leading to an alveolar CO2 level below normal
Where is respiratory control centre?
Medulla
What inputs into respiratory control centre?
- cortical (voluntary) control
- mechanical/stretch receptors in chest wall and diaphragm
- PCO2/pH chemoreceptors in medulla
- PCO2, PO2, pH receptors in carotid body and aortic arch
What mechanism leads to sensation of dyspnea?
- mechanical receptors in chest wall that feed back to respiratory motor neurons
- lung stretch receptors
- irritant receptors in bronchial mucosa activated by stimulation of bronchial mucosa and increased muscle tone and flow
- central and peripheral chemoreceptors (even in absence of activation of respiratory muscles)
What is Homan sign?
- pain with foot dorsiflexion -> DVT
What does brain natriuretic peptide differentiate?
heart failure vs. lung disease
- BNP released by myocytes being stretched
- cleaved into pro-BNP then to biologically active form and inactive amino terminal fragment NT-pro-BNP
-> used to guide CHF therapy
BNP <100 pg/mL or NT-pro-BNP <400 pg/mL: CHF unlikely
BNP >400 pg/mL or NT-pro-BNP >2000 pg/mL: CHF likely
What do you exclude by checking Hct in patient with dyspnea?
Anemia
Normal ABG values (sea-level)?
- pH 7.4 (7.36 - 7.44)
- PCO2: 40 (37 - 42)
- HCO3: 24 (22 - 26)
- PO2: 80-100 mmHg
Direction of change with respiratory pH change re: pH and PCO2?
Opposite directions
Appropriate compensation for acute resp acidosis
HCO3 increase by 10
PCO2 increase by 1
Appropriate compensation for chronic resp acidosis
HCO3 increase by 10
PCO2 increase by 3
Appropriate compensation for acute resp alkalosis
HCO3 decrease by 10
PCO2 decrease by 2
Appropriate compensation for chronic resp alkalosis
HCO3 decrease by 10
PCO2 decrease by 4
What is next step with metabolic acidosis?
Anion gap
Calculate anion gap? Normal range?
Na - Cl + HCO3
= 14 +/- 2
What is delta gap?
- change in anion gap minus change in HOC3
>+6 = another metabolic process (e.g. metabolic alkalosis)
What does + C-ANCA in patient with dyspnea suggest?
- granulomatosis with polyangitis (Wegener’s)
What investigation is suggestive of FB?
- insp and exp X-ray views to look for gas trapping
Resp acidosis or alkalosis causes?
- CNS depression
- Neuromuscular disorders
- Upper and lower airway abnormalities
- Lung parenchyma abnormalities
- Thoracic cage abnormalities
Resp acidosis
Resp acidosis or alkalosis causes?
- hypoxia: pneumonia, pulmonary deem, restrictive lung disease
- primary hyperventilation: CNS disorder, drugs (salicylate), sepsis, hepatic failure
Resp alkalosis
Treatment AECOPD?
- oral/ IV steroids x5d
- abx (increased sputum, purulence, volume): amoxicillin, doxycycline, septra, or 2/3rd gen cephalosporin
- > likely pathogens H. flu, M. catarrhalis, S. pneumonia
- second line abx: b-lactam, resp fluoroquinolone