Electrolytes And Acid-Base Balance

Front 1

serum osmolality formula

Back 1

(2 x sodiun) + (BUN / 2.8) + (glucose / 18); if glucose and BUN are normal then ~ 2 x Na + 10

Front 2

hyponatremia specific etiologies

Back 2

pseudohyponatremia, hypervolemic state, hypovolemic state, euvolemic states, SIADH

Front 3

hypovolemic hyponatremia causes

Back 3

dehydration (with free water replacement)
vomitting
diarrhea
sweating (with free water replacement)
diuretics
ACEIs
renal salt waste
Addison
cerebral sodium waste

Front 4

hypervolemic hyponatremia causes

Back 4

CHF, nephrotic syndrome, cirrhosis, renal insufficiency

Front 5

hyponatremia general presentation

Back 5

Na < 135mEq; symptoms depend on how fast it drops
neurologic in nature
forgetfulness --> disorientation --> obtundation --> seizure --> coma

Front 6

hyponatremia management

Back 6

if asymptomatic --> fluid restriction
mild symptoms --> normal saline + furosemide
seizure or coma --> 3% hypertonic saline
avoid central pontine myelinolysis by correcting Na at 0.5-1mEq/hour or 2mEq if seizure or coma

Front 7

pseudohyponatremia

Back 7

total Na is normal, serum Na is low
for every 100mg/dL of hyperglycemia there's 1.6mEq/L decrease in Na
hyperlipidemia causes Na lab artifact

Front 8

euvolemic hyponatremia

Back 8

psychogenic polydipsisa
hypothyroidism
diuretics
ACEIs
endurance exercise
SIADH

Front 9

SIADH etiology

Back 9

small cell lung CA, pancreas CA, ectopic ADH secretion
TB, lung abscess
head injury, CVA, encephalitis
chlorpropamide, clofibrate, vincristine, vinblastine, cyclophosphamide, carbamazepine

Front 10

SIADH presentation

Back 10

water retention
ECF expansion without edema or hypertension (natriuresis)
hyponatremia
concentrated urine
signs of cerebral edema when hyponatremia is severe (irritability, confusion, seizures, coma)

Front 11

SIADH diagnosis

Back 11

hyponatremia <130mEq/L
urine sodium > 20mEq/L
maintained hypervolemia
↓RAA
low electrolytes in blood (BUN, creatinine, uric acid)
low albumin

Front 12

SIADH management

Back 12

treat underlying cause
fluid restriction to 800-1000mL/d
demeclocycline (AVP inhibitor)
in case of cerebral edema: hypertonic 3% saline 200-300mL IV in 3-4h

Front 13

insensible water losses and hypernatremia

Back 13

↑skin loss (sweating, burns, fever, exercise), respiratory infections

Front 14

gastrointestinal water losses and hypernatremia

Back 14

osmotic diarrhea from gluten or lactose intolerance, some infectious diarrhea

Front 15

transcellular water shift and hypernatremia

Back 15

rhabdomyolysis or seizures cause muscle to take up lots of water

Front 16

renal disease and hypernatremia

Back 16

diabetes insipidus or osmotic diuresis (diabetic KA, nonketotic hyperosmolar coma, mannitol, diuretics

Front 17

central diabetes insipidus etiology

Back 17

neoplastic/infiltrative lessions in hypothalamus or pituitary adenomas, craniopharyngiomas, leukemia, sarcoid histocytosis

surgery, radiotherapy, trauma, anoxia, hypertension, meningitis, encephalitis, TB, syphillis

could also be idiopathic

Front 18

nephrogenic diabetes insipidus etiology

Back 18

idiopathic or secondary to
hypercalcemia
hypokalemia
sickle cell
amyloidosis
myeloma
pyelonephritis
sarcoidosis
Sjogren
lithium
demeclocycline
colchicine

Front 19

diabetes insipidus presentation

Back 19

polyuria, polydipsia
hypernatremia, urine specific gravity <1,010
severe dehydration, weakness
fever, altered mental state
prostration, nocturia

Front 20

diabetes insipidus diagnosis

Back 20

plasma/urine osmolarity ratio falls to the right of shaded area; then if vasopressin response is normal --> central diabetes insipidus, else nephrogenic

Front 21

diabetes insipidus differential

Back 21

primary polydipsia
drug-induced polydipsia from chlorpromazine, anticholinergics, thioridazine
hypothalamic disease

Front 22

diabetes insipidus management

Back 22

CDI: ADH hormone replacement or ADH secretion stimulators (chlorpropamide, clofibrate, carbamazepine); NDI: HCTZ or amiloride or chlortalidone as well as correction of calcium balance

Front 23

hypokalemia from GI losses

Back 23

vomitting, diarrhea, tube drainage

Front 24

hypokalemia from transcellular shift

Back 24

alkalosis
↑insulin
B12 replacement
↑beta-adrenergeic activity (trauma)

Front 25

hypokalemia from urinary losses

Back 25

diuretics
↑aldosterone states (Conn, licorice, Barter, Cushing, renal artery stenosis)
↓magnesium
type I and II RTA

Front 26

hypokalemia presentation

Back 26

muscular weakness to paralysis; arrhythmias; rhabdomyolisis

Front 27

hypokalemia diagnosis

Back 27

normal levels is 3.7-5.2mEq/L; in emergencies do EKG looking for T-wave flattening and U-waves

Front 28

hypokalemia treatment

Back 28

treat underlying cause
give 4-5mEq/Kg/point; IV max 10-20mEq/h
don't use dextrose containning fluids
complication is fatal arrhythmia

Front 29

hyperkalemia from transcellular shift

Back 29

pseudohyperkalemia (secondary hemolysis, mechanical trauma from venipuncture, platelets >1,000,000, WBCs >100,000)
acidosis
insulin deficiency
tissue breakdown (rhabdomyolisis, tumor lysis, seizures)
beta blockers

Front 30

hyperkalemia in acidosis

Back 30

for every 0.1 in pH potassium increases 0.7 points

Front 31

hyperkalemia from renal causes

Back 31

renal failure
hypoaldosteronism (ACEIs, type IV RTA, adrenal enzyme deficiency, heparin)
Addison
amiloride
spironolactone

Front 32

hyperkalemia presentation

Back 32

muscular weakness when K > 6.5
abnormal cardiac conduction
hypoventilation

Front 33

hyperkalemia diagnosis

Back 33

normal levels 3.7-5.2mEq/L; ECG: peaked T waves, wide QRS, short QT or prolonged PR

Front 34

hyperkalemia management

Back 34

if ECG abnormalities -->
calcium chloride (membrane stabilizer)
sodium bicarbonate (alkalosis, not in same IV line as calcium)
glucose/insulin (30-60 minutes to work)
cation exchange resin (absorbs 1mEq og K/gram)
dialysis

Front 35

anion gap formula

Back 35

(Na + K) - (HCO + Cl); normal = 8-14

Front 36

low anion gap metabolic acidosis

Back 36

myeloma (myeloma proteins are cations, HCO and Cl go up)
↓albumin (for every 1 point, 2 point decrease in anion gap)
lithium (decreases Na level) "MAL"

Front 37

normal anion gap metabolic acidosis

Back 37

diarrhea
renal tubular acidosis
uretero sigmoidoscopy
"DiREct (ureter sigmo)"

Front 38

increased anion gap metabolic acidosis

Back 38

lactate
aspirin
methanol
uremia
diabetic ketoacidosis
paraldehyde
propylene glycol
ethylene glycol

Front 39

respiratory acidosis

Back 39

hypoventilation of any cause
COPD
pickwickian
obesity
suffocation
opiates
sleep apnea
kyphoscoliosis
myopathies
neuropathy
effusion
aspiration

Front 40

metabolic alkalosis from H+ loss

Back 40

steroids
GI loss (vomitting, nasgastric suction)
renal loss (Conn, Cushing, ↑ACTH, licorice)
↓Cl intake, diuretics

Front 41

metabolic alkalosis from HCO3 retention

Back 41

bicarbonate administration, contraction alkalosis, milk-alkali syndrome

Front 42

metabolic alkalosis from transcellular shift

Back 42

hypokalemia

Front 43

respiratory alkalosis

Back 43

hyperventilation of any cause
anemia
pulmonary embolus
sarcoid
anxiety
pain
"SAAPP"