#grave's

Not trying to be a dick, here, but my preceptor has not really challenged me until today.  I'm no gunner, but I feel like without some positive pressure, I do get bored very easily.  So let's dig in.

Thyroid, myxedema.

myx = mucin/slimy/mucus = glycoprotein that forms gels, excreted lubricants, interfascial padding, etc.

Myxedema (myx = mucin; edema = swelling) - excessive mucinic (glycosaminoglycan deposition) causing osmotic swelling in areas of the body that can become mucin-laden in response to certain dz processes (i.e. thyroid pathology).  Tx by normalizing thyroid and using topical or intralesional corticosteroids.

Hyperthyroid related myxedema - manifests as exopthalmos and pretibial myxedema caused by high levels of TSH or TSH receptor inflammation that causes TSH to be released.  Classic triad of Graves dz patients is (1) hyperthyroidism, (2) pretibial myxedema, (3) exophthalmos.

TSH receptors located on fibroblasts behind the eyes are stimulated and cause glycosaminoglycan and connective tissue component deposition that causes exophthalmos

inflammation directed at TSH receptors cause lymphocytic infiltrate

increased glycosaminoglycans cause osmotic edema

Hypothyroid related "myxedema" - not related to the definition of myxedema at all, but rather referring to the constellation of symptoms that presents with adult hypothyroidism that essentially is an adult form of cretinism: depression, mental slowness, weakness, bradycardia, fatigue, hypothermia, alopecia, etc.

Hyperthyroid algorithm. 

Minimal Change Disease (MCD).

most common nephrotic syndrome in children

nephrotic syndrome includes massive proteinuria, hypoalbuminemia, edema, hypercholesterolemia

secretion of a toxic lymphokine by abnormal T cells of Hodgkin's lymphoma can cause glomerular injury seen in MCD

MCD is rarely associated with Hepatitis C virus or other infectious etiologies, but HIV pts would be the most consistent demographic

minimal change because no evidence of pathology on light microscopy

electron microscopy shows diffuse loss of podocyte foot processes, vacuolation, and growth of microvilli on the visceral epithelial cells

tx empirically with oral prednisone 60 mg/m2 per day for 30 days (tapering) after proteinuria resolves.  if chronic relapse occurs, add cyclophosphamide immunosuppresant.

CBC Composition

race, sex, and "normal" for the pt should be the standard baseline by which results are judged, because up to 5% of the population show clinically abnormal CBC values but are completely normal.  normal values are shown for white male here.

Hgb/HCT (12.7 - 17.0 Hgb) - concentration of RBCs present in blood which indicates anemia or polycythemia

MCV (81.2 - 101.4) - mean corpuscular volume (RBC size) used to classify anemias into microcytic (<80), normocytic (>80, < 100), or macrocytic (>100) anemias

RCDW (12 - 13.5%)- RBC distribution width which is the MCV standard deviation to determine degree of ansiocytosis to be used as anemia ddx tool 

RBC count (4.0 - 5.6) - /\ count + anemia = thalassemia trait

platelet count (143 - 332) - detect thrombocytopenia or thrombocythemia

WBC count c ddx (3.6 - 9.2) - diagnose acute leukemia, chronic lymphoid or myeloid dz, leukopenia, neutropneia

WBC ddx - neutrophils (1.7 - 6.1), lymphocytes (1.0 - 2.9), monocytes (0.18 - 0.62), eosinophils (0.03 - 0.48), basophils (0 - 0.3)

CBC Clinical Extrapolation

Anemia can be categorized into 3 morphologic groupings: size, shape, and the presence or absence of reticulocytes (baby RBCs that are there because you're making new ones)

Size: microcytic (<80 RBC), normocytic, or macrocytic (>100 RBC)

Shape: round, pointy, target

Reticulocytes: present, absent

Important Labs

Elevated Amylase or Lipase (UpToDate Approach to the patient with elevated serum amylase or lipase)

D-Dimer

D-dimer is generated when plasmin cleaves fibrin causing fibrinolysis, normally, to prevent thrombosis; an elevated plasma concentration of D-dimer indicates recent or ongoing intravascular blood coagulation.

Any clinical scenario that has thrombotic potential will have increased D-dimer, the most commonly implicated being DVT and PE.

Cardiac Labs

BNP - released by the ventricles and will commonly be elevated with ANP (released by atria) when there is increased filling pressure, increased cardiomyocyte stretching or failure.  Both have diuretic (loss of water in urine), natriuretic (loss of salt in urine), and hypotensive effects. They also inhibit the renin-angiotensin system, endothelin secretion, and systemic and renal sympathetic activity.  /\ BNP can be used in pts presenting with unknown causes of dyspnea, and although an /\ BNP is diagnostic of some level of LV dysfunction/HF, it does not exclude other etiologies

CKMB - isoenzyme released by cardiomyoctyes relatively early after an ischemic event. Within 36 to 48 hours, levels return to normal, so diagnostically valuable soon after an event or to discover continued ischemic damage.

Trop I - specific enzyme released as actin and myosine is degraded from cardiomyocytes.  can be used to diagnose a recent (up to 10 days) AMI or a reinfarction.  is very specific and sensitive to cardiac mm., but can also occur with acute PE or other conditions.  if non-cardiac, levels return to normal within 40 hours.  normal levels are usually 0.