Surgery 7 Flashcards
Nasopharyngeal carcinoma is associated with the reactivation of ___ and occurs most commonly in those from what parts of the world?
EBV; Asia (particularly southern China), parts of Africa and the Middle East
Presentation of nasopharyngeal cancer?
Nasal congestion with epistaxis, headache, cranial nerve palsies, and/or serous otitis media (eustachian tube obstruction) due to obstruction of the nasopharynx and invasion of adjacent tissues; early metastatic spread to the cervical lymph nodes may cause a non-tender neck mass
Aflatoxin B1 is a mycotoxin that often contaminates agricultural products and is associated with an increased risk of ___.
Hepatocellular carcinoma
Causes of colonic ischemia?
Non-occlusive, “watershed” ischemia (usually)
Underlying atherosclerotic disease
State of low blood flow (eg, hypovolemia)
Presentation of colonic ischemia?
Moderate abdominal pain and tenderness (usually lateralizes to the affected side)
Hematochezia, diarrhea
Leukocytosis, lactic acidosis
Dx colonic ischemia?
CT scan - colonic wall thickening, fat stranding
Endoscopy - edematous and friable mucosa, cyanotic mucosa, hemorrhagic ulcerations, with a sharp transition from affected to unaffected mucosa
Management of colonic ischemia?
IV fluids and bowel rest
ABX with enteric coverage
Colonic resection if necrosis develops
Discuss the pathogenesis of symptomatic hyponatremia.
Low serum tonicity results in the influx of water into brain cells, leading to swelling and cerebral edema
How long does it take to normalize brain volume?
~48 hours
What is the difference between acute and chronic hyponatremia?
Acute - present for <48 hours, poorly tolerated, high risk for brain herniation
Chronic - present for 48+ hours, better tolerated
Management of symptomatic hyponatremia?
Acute, serum sodium <130, any symptoms of elevated ICP: hypertonic 3% saline boluses to rapidly correct serum sodium
Chronic, serum sodium <120, severe symptoms (seizure) or concurrent intracranial pathology (eg, masses, hemorrhagic stroke): hypertonic saline
Why can you manage acute hyponatremia with hypertonic 3% saline boluses?
Because neural adaptations have no occurred, patients are at relatively low risk of osmotic demyelination syndrome
What is the goal of hypertonic saline infusion?
Raise serum sodium levels by 4-6 mEq/L over a period of hours
Maximum rate of correction to prevent ODS?
8 mEq/L in 24 hours
Presentation - nausea, weakness, confusion, hyponatremia, hyperkalemia, severe hypotension
Acute adrenal insufficiency
Management of acute adrenal insufficiency?
Rapid administration of hydrocortisone or dexamethasone