Critical value and management priority Laboratory Emergency Flashcards
what is the key advantage of the POCT ?
turnaround time is the key advantage of point of care testing
what is the main cause of diabetes insipidus ?
hyposecretion of ADH
what does ADH do ?
causes the kidney to release less water
what is the sodium level in DI ?
hypernatremia
what is the relationship between ADH and sodium levels ?
inversely proportional
what are the classifications of diabetes insipidus ?
cranial - decreased ADH secretion
nephrogenic - resistance to ADH
gestational - degradation of ADH
primary polydipsia - deficit in osmoregulation of thirst
what is the presentation of diabetes insipidus ?
polyuria - more than 3 litres a day
chronic thirst
nocturia
bladder can be grossly enlarged and palpable
what investigations are required for the diagnosis of diabetes insipidus ?
Biochem: plasma glucose
sodium U+E
urine specific gravity
plasma and urine osmolality
24 hour urine collection
fluid deprivation test
MRI of the pituitary
Renal US
what is the normal osmolality of urine ?
300-800
if the urine osmolality increases after the desmopressin test what is the most likely diagnosis in relation to DI ?
cranial DI
if the urine osmolality does not increase after the desmopressin test what is the most likely diagnosis ?
nephrogenic DI
if the urine osmolality is higher than 800 in both the fluid deprivation test and in the desmopressin test what is the most likely diagnosis ?
primary polydipsia
what is the level at which we diagnose hypercalcemia ?
more than 2.6 mmol on two occasions following correction of serum albumin concentration
what are the different classifications of hypercalcemia ?
mild - 2.6 - 3
moderate - 3.01 - 3.4
severe - more than 3.4
what are the most common causes of hypercalcemia ?
malignancy
primary hyperparathyroidism
what drugs cause hypercalcemia ?
thiazide diuretics
lithium
vitamin d and a
what could affect the calcium levels while taking a blood sample ?
prolonged tourniquet
what are the clinical features of hypercalcaemia ?
arrhythmia
ECG
moans
bones
stones
psychic overtones
patient comes with chest symptoms, increased serum ACE and hypercalcemia what is the most likely diagnosis ?
sarcoidosis
what is the treatment for hypercalcemia ?
IV crystalloids and correction of hypovolemia
bisphosphonates may be used
calcitonin as a second line
what are the stages of acute kidney injury?
stage 1 - more than 0.3 increase in create within 48 hours or 1.5 to 1.9 folds increase within 7 days
stage 2 - 2 to 3 fold increase of creatinine from baseline in 7 days
stage 3 - more than 4 mg increase or more than 3 fold increase from baseline in 7 days plus anuria for 12 hours
what are the stages of AKI ?
onset phase
oliguric phase
diuretic phase
recovery phase
patient complaining of GERD and comes with signs of hypercalcemia what is thee most likely diagnosis ?
milk-alkali syndrome
what is the biochemistry in renal AKI vs pre renal AKI ?
in pre renal :
U:Cr - > 40: 1
BUN:Cr - > 20:1
in intrinsic :
U:Cr - < 40:1
BUN:Cr - < 20:1
what are the biochemical changes in plasma in AKI ?
everything is increased except
sodium bicarbonate and calcium
what does an AKI with a negative urinalysis indicate ?
usually indicates a prerenal cause but drugs must still be considered
which diuretics cause potassium loss and which don’t ?
1- loop cause potassium loss in the urine
2- aldosterone antagonists liike spironolactone cause hyperkalemia
what are the main causes of hyperkalemia ?
1- decreased urinary excretion ( drugs, addisons, renal failure )
2- extracellular shift
what are the causes of extracellular shift in hyperkalemia ?
insulin deficiency
beta blocker
digoxin
what drugs cause hyperkalemia ?
ACE inhib
ARBS
spironolactone
what falls under renal failure in the causes of hyperkalemia ?
rhabdomyolysis
tumor lysis syndrome
what are the ECG changes in hyperkalemia ?
peaked T wave
widening of the QRS complex
what is the algorithm for investigation of hyperkalemia ?
find if its an artifact first
check if the patient is on potassium raising medications
AKI or CKD ?
if not consider extracellular shifts
what are the 3 treatment ideas associated with hyperkalemia ?
cardio-protective
causing intra-cellular shift
increasing potassium loss
what are the treatments for each treatment idea in hyperkalemia ?
cardioprotective - if there are any ECG changes then give calcium gluconate
what are the drugs that cause intracellular shift - sodium bicarb, insulin and dextrose, beta 2 agonist ( inhalation )
methods to increase potassium loss - loop diuretic , cation exchange, dialysis
hyponatremia with a normal plasma osmolality differential ?
artifactual hyponatremia
appropriate hyponatremia
what are the risk factors for acute pancreatitis ?
hypertriglyceridemia
hypercalcemia
ERCP
Surgery
what is classic presentation of acute pancreatitis ?
epigastric pain radiating to the back
which is relieved by leaning forward
investigations for acute pancreatitis ?
amylase, lipase (more specific)
what is the management of acute pancreatitis ?
fluid resus
what is myoxedema coma ?
a severe complication of hypothyroidism
what is the classic presentation of myxedema coma ?
An obese elderly woman with yellowish skin, a hoarse voice, a large tongue, thin hair, puffy eyes, ileus, and slow reflexes.
anterior neck scar may be present
what is the management for myxedema coma ?
L-thyroxine 0.2-0.5 mg IV bolus, followed by 0.1 mg IV OD until oral therapy is tolerated
what is the cause of adrenal insufficiency ?
adrenal crisis is due to insufficient cortisol
when is adrenal insufficiency seen ?
in addison’s
what is the clinical picture of adrenal insufficiency ?
increased skin pigmentation
hypotension
hyponatremia
hyperkalemia
increased ACTH
what are the triggers for adrenal crisis ?
1- following stress
2- sudden withdrawal of adrenocortical hormone
3- bilateral adrenalectomy
how is a diagnosis of adrenal insufficiency made ?
An ACTH (Short Synacthen) test
avoid hydrocortisone before the test by 8 hours
what would be a positive synacthen test ?
normally thee cortisol level should rise to 20
below it keda positive
what are the signs associated with acute pancreatitis ?
grey turner’s
cullen’s sign
fox signw
what are the ABG findings associated with aspirin overdose ?
acute overdose is followed by respiratory alkalosis due to hyperventilation followed by metabolic acidosis
what is an important cause of tetany ?
hypomagnesiumenimea
what is the most likely cause of tetany in a patient with chronic pancreatitis ?
hypokalemic alkalosis
