1. Spontaneous bacterial peritonitis. 

- People with cirrhosis are often hypothermic so any temp > 100/37.8 warrants investigation 

- Ascites fluid with more than 250 Polys and a + culture are diagnostic 

- SAAG greater than 1.1 suggests portal hypertension as the source of the Ascites fluids and makes SBP more likely. 

- Treat empirically with third-generation Cephalosporin to cover enteric Gram negatives

- Other ascites facts: in pancreatic ascites, Amylase in the fluid is usually over 1000

- Secondary bacterial peritonitis occurs when there's a rupture of viscous organ into the ascites fluid. because the ascites separates the parietal and visceral peritoneum, the patient will not develop a rigid abdomen even with a raging infection. 

2. The most common cause of bloody diarrhea in the absence of a fever is EHEC.

- Test with stool Shiga toxin. 

- Treat supportively. 

- Do not give antibiotics as it increases the risk of HUS

3. Contraction alkalosis is mediated by Aldosterone. When intravascular volume drops, aldosterone secretion is increased, leading to renal excretion of protons and potassium

4. Rinne test 

- Put the tuning fork on the mastoid and then when the patient can't hear anymore you move it to the air in front of the ear. Air conduction should be twice as long as bone conduction. If this is not the case, thats considered abnormal and suggestive of conductive hearing loss

- Causes of conductive hearing loss: cerumen impaction, chronic otitis media or effusion, otosclerosis, bony tumors within the ear

- Otosclerosis causes conductive hearing loss in adults particularly in their 20s and 30s. It's thought to be potentially autoimmune. Stapes footplate becomes fixed to the oval window. There may be low frequency hearing loss. Treat with hearing aid or stapedectomy. 

5. The hepatojugular reflex is positive when the right ventricle is unable to handle the increased preload that comes from increased intra-abdominal pressure. 

- Causes include right heart failure, constrictive pericarditis (Such as TB), restrictive cardiomyopathy

6. General surgery smorgasbord: 

- No colonoscopy, sigmoidoscopy, or barium enema during acute inflammatory bowel process as the risk of perforation is high. 

- Diverticulitis that does not improve on antibiotics:: suspect intra-abdominal process/publication 

- Causes of toxic megacolon: IBD (UC that erodes through smooth muscle), c.diff, diverticulitis. Mange with bowel rest, pain control, antibiotics. Go to surgery if it doesn't resolve. 

7. Guillain-barre 

- Goes from legs up to arms and cranial nerves. 

- Progresses in hours to days. 

- Affects motor primarily, but can have distal paraesthesias. Can involve autonomic system and respiratory muscles, which can be life threatening. 20-30% of people will end up needing a vent.

- Track development of respiratory weakness and failure by serial measurements of vital capacity: <15mg/kg indicates significantly increased risk of respiratory failure. Other things like chest wall movements, or anything measured on spiro or peak flows or ABG or CXR are not as predictive as VC. 

- Treat with IVIg and plasmapharesis - steroids not indicated. 

8. Hepatic adenoma
- Common in young women with a long history of OCP use. Can also be seen with anabolic steroid use, pregnancy, diabetes glycogen storage diseases. Thought to be hormonal potentially but with unknown pathogenesis

- Path shows enlarged hepatocytes with cytoplasmic inclusions of lipids and glycogen. Nuclei are small and regular but hepatic architecture is distorted (no bile ducts etc)

- Can be found incidentally with imaging or labs (incidentally found LFTs). Elevated alk phos and GGT often indicate multiple adenomas or intratumoral bleed.
- Can present as collapse from rupture and intraabdominal bleed. Risk of bleed in symptomatic adenoma (ie abdominal pain) is 40%. 

- Do not biopsy as the risk of bleed is high.

- Manage symptomatic adenoma with resection. With asymptomatic, treatment is controversial, some resect b/c there is a risk of rupture or malignant transformation (8-13% of adenomas transform), others treat conservatively by d/cing OCPs, serial imaging and following AFPs. Many will spontaneously regress with this.  

9. Focal nodular hyperplasia is a benign tumor in the liver that arises from atypical blood vessels That cause hyperperfusion and local fibrosis. Biopsy shows Kupffer cells and sinusoids 

10. EBV mononucleosis typically will cause cervical lymphadenopathy and pharyngitis. While CMV mono generally does not.
Speaking of pharyngitis, EBV and group A strep are the most common causes; EBV tends to cause posterior LAD and splenomegaly, while GAS tends to cause anterior LAD and doesn't mess with your spleen.