Sodium
The normal values of sodium
135-145 mEq/L
The normal value of potassium
3.5 - 5 mEq/L
The normal value for Magnesium and Phosphate
1.5 - 2.5 mEq/L ; 2.5 - 4.5 mEq/L
Normal values of Calcium
8.5 - 10.2 mg/dL
ionized (4.5-5.5mg/dL)
calc: ical = total serum Ca (mg/dL) -0.83xserum albumin(mg/dL)
Components of NS
154 Na, 154 Cl
3 symptoms of Hypernatremia
Muscle weakness, Restlessness, Extreme thirst, Confusion, Lethargy, Irritability, Seizures, Unconsciousness.
EKG changes in Hypokalemia
typically do not manifest until K+ <3mmol/L
T wave flattening or inversion, depressed ST segments, U waves, prolonged QT interval.
Weakness <2.5mmol/L
Atleast 3 symptoms of Hypermagnesemia and the treatment
Rare in absence of renal failure
nausea, vomiting, neurological impairment, abnormally low blood pressure (hypotension), flushing, headache, Flaccid paralysis, confusion, and coma
EKG changes (similar to hyperkalemia): narrow peaked T waves, QRS widening, reduced P wave amp
Treatment: Calcium (gluconate or chloride), hydration, diuresis, dialysis (renal impairment)
Atleast 3 symptoms of Hypercalcemia
confusion, lethargy, coma, muscle weakness, anorexia, nausea, vomiting, pancreatitis, renal stones, polyuria (from inducing nephrogenic DI), and constipation
EKG: shortened QT interval
Most common cause: 1 hyperparathyroidism and malignancy
Components of LR
130 Na, 4K, 109 Cl, 3 Ca, 28 Lactate, 0 glucose
Rate of Na correction per hour if hyponatremic
increase by 0.5 mEq/l until symptoms have improved or increases by total of 5mEq/l
Safe rate of K+ administration per hour
20 - 40 mEq/h
In K+ >3, recommended oral supplementation
Correction of Hypomagnesemia
<1 mEq/L - Parenteral, 2mEq/kg mag sulfate in IV fluids over 3-6 hrs.
Evaluate vital signs for hypotension, respiratory/cardiac arrest, coma.
Low Mg - hyperreflexive, CNS irritability, hypocalcemia
Treatment of Hypercalcemia
Treatment: Symptomatic w/ Ca >15 mg/dL - vigorous hydration with NS. Rarely diphosphonates(form Ca-P complexes), calcitonin, mithramycin (all inhibit osteoclast resorption)
Normal Na and K daily requirement (mEq/kg/day)
K+ 0.5-1 mEq/kg/day
Na+ 1-2 mEq/kg/day
70kg M patient with Na 124. Calculate the water deficit.
1.6L
Water deficit = TBW x [(Plasma Na/Desired plasma Na) - 1]
Treatment of hyperkalemia
IC Calcium gluconate - seconds to minutes
Glucose, Insulin, NaHCO3 - 30 - 60 min
rectal/oral K binding resins - 1-4 hr (rectal); >6hr oral
Dialysis - Immediate
Treat if >6mmol/L acutely, EKG changes, or symptomatic
DAILY DOUBLE!!
Patient with an NG tube puts out 2.5L over 24 hours. How does his selection of maintenance fluids differ over someone with a duodenal fistula losing 1.5L over 24 hours?
Most frequent cause of Hypocalcemia
low serum albumin
alt causes: acute pancreatitis, massive ST infection, small bowel fistulae, hypoparathyroidism, massive blood transfusions (chelation with citrate) with rates 1 unit/5min
No treatment indicated if normal ionized fraction.
Calculated by Measured total Ca (mg/dL) + 0.8x(4.0 - serum albumin (g/dL))
GI organ with most significant K loss and the volume of fluid per day
Colon, 25 mEq/L; approx 500 mL - 1.7L
70 kg Male found to have sodium level of 112. The estimated Na needed to raise Na to safe, appropriate level _______
Na Deficit = 0.60 x LBW (kg) x [(120 - measure plasma Na)]
Na deficit = 336 mEq
Causes of transcellular flux of K+ into ECF
Sever metabolic acidosis, Insulin deficiency, rhabdomyolysis
Atleast 2 side effects of severe hypophosphatemia and treatment
Impaired tissue oxygenation (d/t low 2-3 dpg levels, muscle weakness, and rhabdomyolysis, Confusion, Appetite loss, Muscle weakness, Feeling tired and upset, Bone pain and fractures, Tooth decay or late baby teeth.
Treat: potassium phosphate (0.08-0.16 mmol/kg body weight) diluted in IV fluids administered over 4-6 hrs.
Atleast 3 Symptoms and treatment of hypocalcemia
<8mg/dL symtpoms - perioral numbness/tingling, or at fingertips, tetany, seizures severe, trousseaus/chvostek sign, prolonged QT interval
symptomatic w/ <3g/dL - 10mL ampule 50-100 mL D5W (93mg elemental Ca) over 10-15 min, or CaCl (232 mg elemental Ca) in 50-100mL D5W over 10-15min
Less severe 1-3g orally
Main ion lost in the stomach and the amount of fluid per day
Cl (130 mEq/L) and 1-4.2L