Uworld Flashcards
Side effects of Diltiazem (non-dihydropyridine CCB)
Constipation, oedema, hypotension
Medications causing constipation
Ondansetron, granisterone, verapamil, diltiazem, iron, aluminium,diphenhydramine, amytriptyline, diclyclomine, haloperidol, morphine, oxycodone, loperamide.
MOA of constipation caused by CCB
slow contraction of colonic smooth muscle
MOA of constipation in diabetic neuropathy
impairement of gastrocolic reflex
MOA of constipation in elderly/neurologic conditions?
dyssenergic defecation
Symptoms of sigmoid volvulus
abdominal pain, nausea, vomitting, bowel obstruction
How are pigment gall stones formed
increased efflux of bilirubin into bile
How are gall stones formed in ileal disease like Chrons
altered enterohepatic circulation
How are pigment gall stones formed
increased efflux of bilirubin into bile
How are gall stones formed in ileal disease like Chrons
altered enterohepatic circulation
Cause of diabetic diarrhea that persists at night (even with fasting) and day
autonomic neuropathy causing disordered motility of small bowel and colon and increased secretions
Risk factors for diabetic diarrhea
Impaired glucose control and vascular (obesity and HT)
Cause of diabetic diarrhea that persists at night and day
disordered motility of small bowel and colon
Risk factors for diabetic diarehea
Impaired glucose control and vascular (obesity and HT)
Diarrhea in exocrine pancreatic insufficiency
steatorrhea
What nutrient deficiency is seen with PPI
calcium, iron, magnesium and vitamin B12
PPI improve lipase as acid inactivates lipase
MOA of constipation in pregnancy
progesterone causes decreased colonic smooth muscle activity
Pathophysiology of ADH/RAS in cirrhosis
cirrhosis causes vasodilatation, reduces blood flow, activates RAS and increase ADH, increases renal Na reabsorption (hence decreasing urine sodium). This increases TBW but due to third spacing they are intravascularly depleted causing hypervolumic hypernatremia in advanced cirrhosis
MOA of constipwtion in pregnancy
progesterone causes colonic smooth muscle activity
Effects of pregnancy on GI tract
progesterone decreases LE tone-GERD
estrogen increases cholesterol secretion in bile, progesterone decreases GB motility-GB stones
Gravid uterus mechanical effect-flatulence
gravid uterus increase mechanical pressure-hemorrhoids
constipation after a traumatic vaginal delivery MOA
defecatory dysfunction, inablity to relax pelvic floor muscles
Rectoceles can occur after multiple vaginal deliveries
Most common cause of hepatic abscess in the US
Staph aureus by hematogenous route
Bacteria causing ascending cholangitis/hepatic abscess from direct invasion of nearby source?
Gm negative enteric bacilli like E coli, Kleibsiella, enterococcus
How does Entameoaba histolytica cause hepatic abscess
ascending from the colon through portal venous system
How does enteric bacteria cause hepatic abscess?
ascending through the biliart tract (ascending cholangitis), portal vein pyemia, direct invasion from an adjacent area (cholecystitis)
Pathophysiology of GERD
decreased LES tone, disruption of GE junction like in hiatal hernia
Complications of GERD
stricture, erosive esophagitis, Barrett esophagus
Food getting stuck in esophagis?
Stricture
Indectious esophagitis generally in immunocompromised organism?
Candida, CMV, HSV
New onset odynophagia in the setting of chronic GERD?
erosive esophagitis with esophageal ulcers
Enterocytes with foamy cytoplasm?
Abetalipoprotenemia due to accumulation of lipids
Nausea, fever, anorexia, hypotension after a surgery. What is it?
Inhaled anesthetic like halothane causing acute liver injury.
What kind of liver injury does halogenated anesthetics cause?
Hepatocellular injury, ranging from asymptomatic rise in liver enzymes to fulminant hepatitis. Liver shrunken on biospy.
Lab feautures of anesthtic induced hepatotoxicity?
Elevated aminotransferase, prolonged PT, leukocytosis and eosinophilia. Note distended abdomen veins and palmar erythema are features of end stage liver disease. Not acute liver toxicity.
Most common cause of acute cholecystitis?
Obstruction of the cystic duct.
complications of cholecystitis?
gangrene, perforation, pericholecystitis, generalised peritonitis.
imaging of choice for cholecystitis?
ultrasound
characteristics of cholecystitis on HIDA scan?
Gall bladder will not be visualised due to obstruction.
Characteristics of cholecystitis on ultrasound?
gall bladder thickening, pericholecystic fluid and positive sonographic Murphys sign
short gastric veins drain blood from ?
fundus to splenic vein
What causes splenic vein thrombosis and hence gastric varices?
Pancreatic inflammation like chronic pancreatitis, pancreatic cancer.
How do the azygous vein drain
drains blood from the esophageal vein into the SVC. Also provides collateral circulation between SVC and IVC and hence becomes enlarged with caval obstruction.
Blockage of superior mesentric vein cause varices where?
LOWER stomach, not upper regions. Remember SMV drains blood from the lower stomach and small intestine.
cause of atresia of jejunum, ileum and colon?
vascular occlusion
Where is apple peel atresia seen?
in superior mesenteric artery obstruction. Apple peel: blind ending proximal jejunum, a length of absent bowel and mesentery, a terminal ileum spiraled around an ileocolic vessel.
when is 5HT3 used for nausea?
visceral nausea like gastroenteritis, chemotherapy and anesthetics
When are dopamine antagonist used for nausea?
central nausea like migraines
When are H1 antagonists and muscarinic acetylcholine receptor antagonists used for nausea?
vestibular nausea like motion sickness
when is somatostatin receptor agonist (octreotide) used?
carcinoid and VIPOma diarrhea
Pathophysiology of umbilical hernia?
incomplete closure of abdominal muscles; defect in linea alba
when to treat umbilical hernia?
elective surgery after the age of 5
pathophysiology of ompahlocele and gastrotrichisis
failure of extraembryonic gut to return to the abdominal cavity
risk factors for chronic pancreatitis?
alchol, recurrent acute pancreatitis, smoking
What does chronic pancreatitis cause
endoceine (insulin) and exocrine(lipase, elastase, amylase, trpysin and chymotrypsin) deficiency
clinical features of chronic pancreatitis
steatorrhea, low fecal elastase, positive sudan staining, elevated hemoglobin HbA1c
what happens to pancreatic bicarb production in chronic pancreatitis?
due to destruction, pancreatic bicarb production decreases
characteritiscs of celiac disease
villous atrophy, abdominal pain, can have steatorrhea, iron deficiency anemia.
chronic infection with which 2 viruses cause hepatocellular carcinoma HCC?
Hep B and Hep C. Ongoing infection leads to increased hepatocyte turnover, generation of local inflammatory cytokines which can result in genetic mutations that lead to malignant transformation.
mechanism hoe HBV cause HCC
Intergration of HBV DNA into the host genome, production of oncogenic viral proteins called HBx that is assocaited with cellular growth, also aftects p%# which is tumor suppresor
Which viruses intergrate into host genome?
Hep B, HPV
How are calcifications formed in chronic alchoholic pancreatitis.
Protenaceous material precipitate to form ductal plugs, which then calcifies.
How does chronic pancreatits cause diarrhea?
digestive enzyme deficiency
Where is bile malabsorption seen?
ileal resection, chrohns
How do gastrinomas cause diarrhea/malabsorption?
hypersecretion of HCl that cause deactivation of digestive enzymes
how does celiac disease cause malabsoption?
immune mediated enteropathy
Gastric relation in systemic mastocytosis
abnormal proliferation of mast cells that secrete histamine, That causes hypersecretion of gastric acid by pareital cells in the stomach as well as hypotension, flushing and pruritis
What stimulates gastric acid secretion?
Histamine increases cAMP, acetylcholine increases intracellular calcium, gastrin binds to cholecystokinin B and increases intracellular calcium
Mast cell proliferation associated with which mutation
Mutation in KIT receptor tyrosine kinase
where is gastric hypomobility seen?
diabetes, uremia and hypothyroidism
pancreatic endocrine tumor secretions?
gastrin (ZE) insulin, glucagon, somatostatin(diarrhea, cholelitiasis, hyperglycemia), VIP(watery diarrhea, hypokalemia, acholyrydia.
Acid base changes in diarrhea?
low Ph, low paCO2 and low bicarb
Causes of anion gap metabolic acidosis
MUDPILES
Causes of non anion gap metabolic acidosis
HARDASS
Causes of metabolic alkalosis
nasogastric suctioning or severe vomitting, diuretic overuse, primary hyperaldosteronism
causes of respiratory acidosis (hypoventilation)
CNS depression (opoid overuse), OHS, nuromuscular weakness, COPD
Causes of respiratory alkalosis (hyperventilation)
Acute V/Q mismatch (PE, pneumonia), anxiety, inadequate pain control, high altitude, pregnancy
Changes when a patient with SIADH is given Vaptans (tolvaptan) or V2 antagonistsVasopressin?
Plasma osmolarity and urine output increases, serum sodium no change. No effect on Na and K excretion.
Changes in SIADH prior to treatment?
low serum osmolarity, low serum Na, low urine output, high urine osmolarity
CHanges by thiazides?
renal excfretion of Na and water (hence increase urine output), decreased plasma osmolarity (hyponatermia)
Changes due to dehydration?
dehydration causes increased plasma osmolarity, activates RAS, increas ADH (reduces urine output), and sodium excretion (due to alsosterone)
Changes due to mannitol?
increases plasma osmolarity and inhibits water reabsorption in the renal tubules. Sodium excretion is increased due to solvent drag.
Which poisoning in a pt with altered mental status, tachypnea and anion gap?
Aspirin (salicylate) poisoning
Symptoms of aspirin poisoning?
tinnitus, hyperventilation, nausea and vomitting. Uncoupling of oxydative phosphorylation leads to hyperthermia and anaerobic respiration and hence lactic acidosis. ALtered mental status due to direct effcet on CBS and neuroglycopenia.
Symptoms of ethanol intoxication
slurred speech, respiratory depression, nystagmus, decfreased cordination, CNS depression.
Symptoms of carbon monoxide posisoning?
many people in household flu like symptoms, headaches and altered mental status.
causes of hypophosphatemia?
internal redistribution {increased insulin secretion-refeeding, acute respiratory alkalosis-stimulates glycolysis, hungry bone syndrome-after parathyroidectomy}
decreased intestinal absorption {chronic poor intake, aluminium or Mg antacids since they bind phosphorus, steattorhea}
increased urinary excretion {primary and secondary hyperparathyroidism, vitamin D Deficiency, primary renal phosphate wasting, fanconi}
Mechanism of hypophosphatemia in refeeding?
redistribution of phosphorus from the serum into the muscle and hepatic cells in an effort to maintain cellulat energy metabolism (ATP production)
Hungry bone syndrome?
2-4 days after parathyroidectomy. Hypocalcemia and hypophosphatemia. Most prominent tetany.
Causes of SIADH?
CNS disturbances (stroke, h`age, trauma), meds(carbamazapine, SSRIs, NSAIDs), lung disease(pneumonia), malignancy (small cell lung cancer)
Clinical findings of SIADH?
nausea, forgetfullness (mild hyponatremia), seizures, coma (severe hyponatremia), euvolemia (moist mucous membranes, no odema, no JVD)
SE of canagliflozin?
increases urinary glucose excretion. Linked to UTI and hypotension.
Recurrent pyelonephritis and scarring on US?
reflux nephropathy. If uncorrected scarring (upper and lower pole) can lead to secondary hypertension.
Symptoms of ADPKD?
In adulthood, hematuria, HT and parenchymal cysts on US
Symptoms of multicystic dysplastic kidney?
multiple non communicating cyst with intervening dysplastic tissue. Early severe renal insufficiency.
symptoms of PUV?
b/l hydronephrosis and calcyleal dilatation. Only in males due to malformation of the Wolffian duct.
What happens in nephrogenic DI
serum osm high (same in central DI), urine osm after water deprivation low (same in central DI), urine osm after desmopressin administration no change (vs in central DI, urine osm will increase after desmopressin)
What happens in primary polydypsia?
serum osm low, urine osm after water deprivation increased, urine osm with desmopressin no change
mechanism in HUS?
bacterial toxins injure blood vessels, cause platelet aggregation and microthombi in blood vessels
features of HUS
bloody diarrhea, hemolytic anemia with schistocytes, thrombocytopenia, acute kidney injury
mechanism in PSGN?
immune response against streptococcal antigens that deposit in the glomerulus
mechanism in HSP
IgA immune complex deposition in the small blood vessel
mechanism in Kawasaki
vasculitis in medium sized arteries
mechanism in DIC
widespread activation of coagulation cascade
Why does post op urinary retension occur?
decfeased micturation reflex activity, decreased contractility of the bladder detrusor, increased vescical sphincter tone
Rx of post op urinary retension?
muscarinic agonist (bechanichol) or a alpha 1 blocking agent
Rx of bladder outlet obstruction sec to prostate hypertrophy
Finasteride, 5 alpha reductase inhibitor
Rx of urge incontinence?
Oxybutynin which is an antimuscarinic
Mechanics at high altitude?
Low piO2 leads to hypoxemia with hyperventilation and respiratory alkalosis.The hypoxemia and alkalemia cause symptoms like headache, fatigue, lightheaded. Kidney respons by creating metabolic acisosis by decreasing bicarb resabsoption and incfreasing erythropoeitin secretion. Alkalosis causes legft shift in Hb dissocoation curve.
What happens to renal dynamics in hypovolemia?
Decreased RPF, decreased GFR, increase FF
Kidney biospy of intimal thickening, luminal narrowing of the renal arterioles with glomerular sclerosis seen in what?
Hypertensive nephrosclerosis
Pathologic hypertensive changes in kidney?
medial hypertrophy, fibrointimal proliferation in the renal arteriole. There is also hylanie arteriosclerosis and glomerulosclerosis.
Urinalysis in hypertensive nephrosclerosis?
Proteinuria in advance disease, otherwise normal
Pathologic findings in analgesic nephropathy
papillary necrosis, tubolointerstitial nephritis
Pathologic findings in fibromuscular dysplasia?
fibromuscular ridges alternating with areas of anuerymal dilatation affecting the main renal artery
Renal histology in hepatitis C
diffuse thickening of the glomerular basement membrane without glomerular hypercellularity
Renal histology in multiple myeloma?
light chain cast nephropathy
What causes hemoptysis in cystic fibrosis?
bronchiectasis which stimuleates bronchial artery hypertrophy
What can cause life threatening hemoptysis?
bleeding from high pressure bronchial system not low grade pulmonary system
Where do you see large PaO2 gradient between alveoli and pulmonary venous blood and normal pCO2?
diffusion impairement (emphysema, pulmonary fibrosis)
What happens in normal arteriolar ventilation?
alveolar and pulmonary capillary pO2 reaches equilibrium at 104.
Where is intrapulmonary shunting seen?
When alveoli are filled with fluid (pneumonia, pulmonary oedema), or collapse atelectasis and alveolar ventilation is essentially zero.
dynamics in intrapulmonary shunting?
alveolar paO2 equilibrates wigth venous blood at 40 when alveolar ventilation is zero.
What happens in poor alveolar ventilation (hypoventilation)?
no gradient is created
Landmarks for thorcaocentesis?
between 6th and 8th in midclavicular line, between 8th and 10th in the midaxillary line and 10th and 12th paravertebral line
what happens if thoracocentesis needle is inserted lower than 9th rib?
damage to intraabdominal structures
how should throcacocentesis be performed to avoid damage to the intercostal vessels?
above the upper border of the rib
prolonged pauses in airflow despite normal thoracic and diaphragmatic activity?
OSA. Apneic episodes may result in hypoxia and hypercapnea.
breathing pattern in Chene sttoke heart failure?
a cyclical pattern in which apnea is followed by gradually increasing then decreasing tidal volumes (cresendo decresendo) until the next apneic period.
breathing pattern in redulced lung compliance?
rapid shallow breathing, to restore minjute ventilation and minimize work of breathing
breathing pattern in neruromuscular weakness?
reduced thoracic and diaphragmatic muscle activity with rapid shallow breathing
breathing activity in diabetic ketoacidosis Kussumal breathing?
deep rapid breathing associated with increased thoracic and diaphragmatic activity
Pathology of granulomas in sarcoidosis?
non caseating granulomas (non-necrotic aggregates of epitheloid macropahges and multinucleated giant cells)
clinical features of sarcoidosis?
lungs (reticular, nodular infiltrates), lymph nodes(hilar LN), skin (erythematous rash), eyes (anterior uveitis), pulmonary symptoms(cough, dypnea, SOB0, constituional (fever, weight loss, fatigue, night sweats, arthalgia)
Pathology in Hodgkin lymphoma?
Reed sternburg cell
pathology of sqamous cell carcinoma of the lung
sheets of keratin containing malignant cells
pathology of adenocarcinoma of the lung
glandular differentiation with atypia
features of Mycobacterium avium complex?
non caseating and caseating granulomas (generally in severly immunocompromised), has lung cavitations
pathology in TB?
caseating granuloma with acid fast bacilli
features of asthma
intermittent respiratory symptoms, normal CXR, sputum eosinophils, reduced FEV1<80%
common triggers of asthma?
animal dander, dust mites, pollens. cockroaches, environmental pollutants, NSAIDS, aspirin, non selective Beta blockers, URI, GERD.
Food is mostly not a trigger
What to suspect when a patient with MI develops acute SOB?
acute pulmonary oedema affecting MI of lateral ventricle. Elevated hydrostatic pressure in the pulmonary venous system leads to engorged pulmonary capillaries with transudation of fluid into the alveoli appearing as acellular pink material
pathology in fat embolism syndrome?
fat globules and bone marrow cells in pulmonary arterioles.
pathology in pulm h`age like Goodpasteur or other vasculitis?
focal necrosis of alveolar wall with intraalveolar h`age
pathology in chronic lung congestion?
hemosiderin laden macrophages (heart failure cells) as macrophages engulf the RBCs that leak from the alveolar capillaries damaged by high intravascular pressure.
where are elastases (neutral protease) derived from in the alveolar fluid?
alveolar macrophages and infiltrating neutrophils.
what is neutrophil elastase and macrophage elastase inhibited by?
serum alpha 1 trypsin and tissue inhibitors of metalloproteinases respectively.