Lab med 6

What has an elevated reticulocyte count?

Sickle cell *

Controls the amount of water reabsorbed by the kidney

ADH

What is ADH release stimulated by

Increased osm or decreased blood volume

SIADH _____ ADH

Increases

Neurogenic (Central DI) _____ ADH

decreases

Hypovolemic shock ____ ADH

increases

Hypervolemia ____ ADH

inhibits

What is the #1 treatment for Increased ADH

Fluid restriction

DI = " " and SI = " "

Dry inside

Soaked inside

DI or SIADH? - Low ADH and water

DI

DI or SIADH? High ADH and water intoxicaton

SIADH

DI or SIADH? Low urine output

SIADH

DI or SIADH? - Low sodium

SIADH

DI or SIADH? - high urine output

DI

DI or SIADH? - high sodium

DI

DI or SIADH? risk of seizures

SIADH

DI or SIADH? risk of hypovolemic shick

DI

Tx DI

DDAVP

Tx SIADH

Hypertonic saline

Young patient, tachy, weight loss, high catecholamines

Pheochromocytoma

Pheochromocytoma is an adrenal tumor that is characterized by the overproduction of _____

catecholamines

First step in diagnosing Pheochromocytoma

Suspicion.... then 24 hour urine for catecholamines*

Brief summary sequence for Pheochromocytoma

Urine --> Plasma --> Imaging (look at diagram in slides)

Urine test for Pheochromocytoma tests for

VMA, HVA, catecholamines

Which one is not normally found in adults

HVA

What is important when doing a urine test for Pheochromocytoma

Prep patient because many factors like food, coffee can interfere

What are you measuring in the plasma for Pheochromocytoma?

Normetanephrine & Metanephrine

What is important to know about the plasma test for Pheochromocytoma

It has a high negative predicitve value, meaning if concentrations are normal, it is unlikely that they have it

GH is secreted by the

anterior pituitary

GH increases before growth plate closed

Gigantism

GH increases after growth plate closed

Acromegaly

GH decreased in

Pituitary insuffiency

Dwarfism

Failure to thrive

Delayed sexual majority

GH in anorexia

increased

Major Sx or stress can ___ GH

increase

Testosterone is an androgen derived from

DHEA and Androstenedrione

also produced in normal adrenal glands and ovaries*

Male normal testosterone level

300-1000

Transforms testosterone into estrogen in men

Aromatase

testosterone is produced by

leydig cell of testicle

Risks of exogenous testosterone

increased bone loss, risk of PE, a-fib, acute kidney injury

PCR tests lack ____, increase false _____, overly ______

specificity

false positives

overly sensitive

Rapid antigen tests lack ____, increase false _____, overly ______

Sensitivity

flase negatives

specific

HIV --> when you have a positve EIA what must you do?

Confirm with western blot (it seperates blood proteins more specifically)

Most widely used test for HIV that detects the aB, CANT detect in early stages tho

Elisa screening test

This test can miss late infection, but best when done EARLY

P24 antigen capture assay

(detects viral protein p24)

What is now available for even earlier than P24?

NAAT

Lymes disease - what is important about the treatment

Treat even with a negative test, prophylaxis with DOXy

What test is perferred for Dx of lymes

Modified two tiered (2 elisa tests with different target protein antifens of Borriella)

If test one is negative do you need another test

no

Lyme positve, if there is a positve on both tests do u need western blot

no

CSF - what is used to assist in dx?

opening pressure

Never do a spinal tap unless you exclude

intracranial HTN with a CT

What opening pressure is dx of intracranial HTN

250

yellow, orange or pink discoloration of the CSF

Xanthochromia

Lymphocytosis of CSF...

viral, fungal, and TB infections of CNS

PMNs in CSF...

Bacterial menigitis

Austrian triad under microscopic exam of CSF

Pneumonitis, endocarditis, menigits strep pneumo

(look for strep, stiff neck, fever, new murmur in vingette)

Most sensative indicator of pathology within the CNS

Protein level

Protein level corrected by

subtracting 1 mg per dL of protein for every 1000 RBCs

Infections do what to glucose

decrease

Viral do what to glucose

normal

Normal CSF.. r/o infection?

no

Gold standard to confrim bacterial mengigits

CSF culture

The leading cause of viral menigits

Enterovirus

Leading cause of bacterial menigitis

S.pneumo, N. menigitis

Look at summary chart in sldies

*