Respi 2 Flashcards
What are the pathological lung findings of Primary TB and Reactivated TB?
> Primary TB: Ghon focus of walled-off TB and caseating necrosis in the lower lobes; Ghon complex if it involves lymph nodes.
Reactivation: infection spreads bronchogenically to upper lobes and results in caseous and liquefactive necrosis, creating cavitary lesions
What is the common presentation of Mycobacterium avium complex (MAC)? What is the treatment?
MAC is an opportunistic infection found in HIV pts w/ CD4+ count. More commonly presents with anemia, hepatoplenomegaly, inc. ALP, inc. lactate dehydrogenase. Optimum growth at 41C.
>Tx: clarithromycin or azithromycin + rifabutin (or ethambutol)
Pancoast syndrome results from a Pancoast tumor of the lung apex invading surrounding structures. How may Pancoast syndrome present?
> Shoulder pain radiating to axilla/scapula (MC) due to lower brachial plexus involvement.
Horner syndrome (cervical sympathetic ganglion).
UE edema (compressed subclavian vessels).
Spinal cord compression, paraplegia
Why is Hypoxemia (PaO2 below 60 mmHg) a major contributor to the respiratory drive of patients w/ COPD?
COPD pts have dec. sensitivity to PaCO2, and so their response to changes in PaCO2 is blunted. Since these pts have difficulty breathing, they will become hypoxemic, and their peripheral chemoreceptors will activate to induce hyperventilation. Giving O2 therapy will inc. PaO2 and dec. peripheral chemoreceptors stimulation, thus dec. RR.
How are TLC, RV, and FVC affected in an aging patient?
Aging patients have dec. chest wall compliance and inc. lung compliance (loss of elastic recoil) – unchanged TLC, inc. RV, dec. FVC.
Why does Sarcoidosis (and other granulomatous diseases) present w/ Hypercalcemia?
Sarcoidosis involves widespread systemic granulomatous formation. These granulomas contain macrophages that have 1alpha-hydroxylase, an enzyme that can activate Vit D.
What is the most common pulmo function indicator for Restrictive lung disease caused by obesity?
Dec. ERV is the MC indicator of obesity-related dses. Obesity presents w/ dec. chest wall compliance (wt gain) and dec. lung compliance (microatelectasis) – inc. RR, dec. TV (rapid-shallow breathing). There is also dec. FRC.
Why do Interstitial Lung Diseases present w/ supernormal expiratory flow rates?
Interstitial lung dse can cause pulmonary fibrosis, w/c increases elastic recoil and radial traction on airways, leading to widened airways. The decreased airflow resistance causes supernormal expiratory flow rates.
Theophylline is an adenosine receptor antagonist and phosphodiester inhibitor, metabolized by hepatic cytochrome oxidase. What drugs can inhibit these enzymes and cause theophylline toxicity?
> Cimetidine, Ciprofloxacin, Verapamil, Macrolides.
>Toxicity: CNS stimulation (seizures, tremor), GI disturbance, cardiovascular problems (hypotension, arrhythmias)
What is the most common cause of Chronic bronchitis?
> MCC: tobacco smoke
>Others: air pollutants, grain, cotton, silica dusts
How does the pulmonary function test for COPD (bronchitis, emphysema) present?
> Both: Dec. FEV1/FVC
>Emphysema: inc. TLC, FRC, RV (air trapping)
How does the pulmonary function test for Restrictive lung diseases present?
Dec. TLC
Inc. FEV1/FVC
Dec. FVC
What are the neuroendocrine markers of tumors of neuroendocrine origin (small cell Ca of lung)?
Neural cell adhesion molecule (NCAM, CD56)
Enolase
Chromogranin
Synaptophysin
What are the 4 stages of Lobar pneumonia?
1) Congestion (24 hrs): red, heavy, boggy lobe; vascular dilatation, alveolar exudate w/ bacteria.
2) Red hepatization (2-3 days): red, firm lobe w/ liver consistency; alveolar exudate has RBCs, neutrophils, fibrin.
3) Gray hepatization (4-6 days): gray-brown lobe; RBCs disintegrate, exudate has neutrophils and fibrin.
4) Resolution: restored normal architecture; enzymatic digestion of exudate.
