1. Pleural effusions
- Need 150 cc to see on CXR, need 5-10 cc to see on chest CT
- Pleural fluid pseudotumors more common in pleural effusion assoc with CHF
2. Factors that make an incidentally found solitary pulmonary nodule more likely to be malignant
- Size (>1 cm more likely to be malignant)
- Edge (spiculated/stellate more likely malignant)
- Presence and pattern of calcification
- Growth/change from prior images
- Clinical factors (history of lung fibrosis, asbestosis, etc.)
- Age (> 40 more likely malignant)
- Smoking hx
- Travel history and history of living in areas where granulomatous disease is endemic (over 40% of people have nodules in some endemic histoplasmosis regions)
- History of other malignant diseases (mets?)
3. PET scans
- Pt must be fasting for 6 hours beforehand, and no glucose-- no dextrose in saline, no dextrose-saline in riders, no steroids, diabetics must be carefully titrated with insulin to the correct levels
- Some tumors can produce false negatives (esp benign lesions like hamartomas and carcinoids)
- Some tissue can produce false positives-- like moving muscle, so patients must be very still
- 95% sensitive, 85% specific for evaluating solitary lung nodules
4. Pneumonectomy
- Post op, the entire hemithorax with the removed lung will gradually fill with fluid
- Decrease in the fluid is usually bad, as it means that the fluid is either leaking out through the surgical wound in the chest or leaking into the airway through the residual bronchial stump
5. FOBT
- Screening test
- False positives can be caused by recent ingestion of red meat (Hb in meat will light up the test), trauma during rectal exam. Thus patient should not be eating red meat before the test
- If someone is going to be admitted for GI bleed, it should be significant-- ie visible on the glove as either red or black. If blood is not grossly visible, the bleed is not serious enough to require admission. Thus don't do an FOBT in the ER
6. Melena
- Is midnight black, tarry/sticky, and has a strange/bad odor different from typical stool
- Not just dark, otherwise normal appearing stool.
- Things that can cause dark-appearing stool: pepto bismol, milk of magnesia, iron supplements
7. Phosphodiesterase inhibitors
- Nonselective: caffeine, theophylline, IBMX
- PDE 3 inhibitors: milrinone, cilastazol, imarinone, enoximone. These guys are used as vasodilators (milrinone in pHTN and s/p cardiac surgery to lower afterload and increase contractility, cilastazol in PAD and SAH vasospasm)
- PDE 4 inhibitors: rolipram, ibudilast, roflumilast
*PDE4 is in immune cells, so PDE4-I are often used as anti-inflammatories esp in people with inflammatory lung diseases (asthma, copd)
- PDE 5 inhibitors: dipyridamole aka persantine, all the viagra-type drugs (sildenafil, tardalafil, etc)
- PDE 10 inhibitors: papaverine (opium alkaloid antispasmotic). Treats GI/ureter spasm, can induce vasospasm in coronary and cerebral vessels (use in SAH, angina). Can be directly applied to blood vessels in microsurgery
- Also, forskolin is an Adenylyl cyclase activator.
8. Prinzmetal's angina
- Tends to occur at the same time every day
- Diagnosed clinically but can also be diagnosed with ergonovine infusion in cath lab
- Tx with calcium channel blockers
9. Cardiology Potpourri: 
- ACE inhibitors increase serum K (via decreased aldosterone secretion). {Detailed explanation of mechanism}
- In older adults with sinus bradycardia, it's better to do atrial pacing only rather than AV pacing; there is much less risk of a-fib.
- In the US, people who need ventricular pacing will usually get AV pacing, because people who just get V pacing get pacemaker syndrome (loss of A-V synchrony, loss of atrial kick contribution to ventricular filling, decreased cardiac output). {more on pacemaker syndrome}
- Indications for inpatient admission for CABG: unstable acute coronary syndrome, cardiogenic shock requiring balloon bump bridge to CABG. If someone is stable, they can just come in the AM of the procedure and go to the CT surg service, no need to be admitted the night before to cards.
- Causes of PVCs: electrolyte abnormalities, ischemia, ventricular ectopy -- treat this when people are symptomatic (i.e. syncopizing) with b-blockers, ca-channel blockers, ablation.
10. Bradycardia
- If it's regular, and you don't see p-waves: junctional rhythm, Afib + complete block, dig toxicity
- If you don't see P-waves, it's not a cut-and-dry AV nodal block, which will always present with p-waves (without a-fib)
- Sinus brady can be caused by beta-blocker or ca-channel blocker toxicity; treat with glucagon 1mg which is a chronotrope that acts directly on the cardiac myocardium, bypassing the entire sympathetic pathway.
- Other common causes: hypothyroidism, increased vagal tone, anorexia, sick sinus syndrome, hypothermia.
- Extensive differential