Fiser ABSITE Ch. 9 Fluids Flashcards
Roughly ___ of the total body weight is water (men); ___ have a little more body water, ____ have a little less
2/3, infants, women
2/3 of water weight is located where? and the other 1/3?
intracellular (mostly muscle), extracellular
2/3 of extracellular water is located where? and the other 1/3?
interstitial, plasma
What determines plasma/interstitial compartment osmotic pressures? what about intracellular/extracellular?
proteins, Na
Most common cause of volume overload? what is the first sign?
iatrogenic, weight gain
What is the meqs in 0.9% NS?
Na 154 and Cl 154
Lactated Ringer’s has the ionic composition of plasma, what is it?
Na 130, K 4, Ca 2.7, Cl 109, bicarb 28
How to calculate plasma osmolarity and what is the range of normal?
(2 x Na) + (glucose/18) + (BUN/2.8)
280-295
How to estimate volume replacement in cc/kg/hr
4 cc/kg/hr for first 10 kg
2 cc/kg/hr for second 10 kg
1 cc/kg/hr each kg after that
(110 cc/hr for 70 kg man)
What is the best indicator for adequate volume replacement?
urine output
During open abdominal operations, fluid loss is ___ L/hr unless there are measurable blood losses
0.5-1.0 L/hr
Usually do not have to replace blood lost unless it is >____ cc
500
Insensible fluid losses is ___ cc/kg/day, 75% skin, 25% respiratory (pure water)
10
IV replacement after major adult GI surgery:
During operation and 1st 24 hours use ____.
After 24 hrs switch to ___
LR
D5 1/2 NS with 20 mEq K
D5 1/2 NS @ 125/h provides 150g glucose per day or ___ kcal/day
525
Stomach secretes ___ L/day
1-2
Biliary system secretes ___ mL/day
500-1000
Pancreas secretes ___ mL/day
500-1000
Duodenum secretes ____ mL/day
500-1000
Normal K+ requirement is ___ mEq/kg/day
0.5-1.0
Normal Na+ requirement is ___ mEq/kg/day
1-2
Which bodily fluid has the highest concentration of K+
saliva
Primary electrolyte(s) lost in the: Stomach? Pancreas? Bile? Small Intestine? Large Intestine?
Stomach H+, Cl- Pancreas HCO3- Bile HCO3- Small intestine HCO3-, K+ Large intestine K+
Gastric losses should be replaced with which fluid?
D5 1/2 NS with 20 mEq K+
Pancreatic/biliary/small intestine losses should be replaced with which fluid?
LR with HCO3-
Large intestine (diarrhea) losses should be replaced with which fluid?
LR with K+
GI losses should generally be replaced ___ ?
cc/cc
UO should be kept at least ___ cc/kg/hr; should not be replaced; usually a sign of normal postoperative diuresis
0.5
Normal range of K+
3.5-5.0
Initial finding of hyperkalemia on EKG?
peaked T waves
Tx for hyperkalemia:
____ membrane stabilizer for heart
____ causes alkalosis, K enters cell in exchange for H
____ K driven into cells along with glucose
___ binder
___ if refractory
Calcium gluconate Bicarb 10 U insulin and 1 ampule of 50% dextrose Kayexalete Dialysis
EKG with hypokalemia?
t waves disappear
Hypokalemia tx: may need to replace ___ before you can correct K+
Mg+
Normal range of sodium?
135-145
What are the sx of hypernatremia?
restlessness, irritibility, ataxia, seizures
Correct hypernatremia with ___ slowly to avoid ___
D5W, brain swelling
Formula for total body water?
0.6 x patient’s weight
Formula for total free water deficit
TBW x (([Na+]/140) -1)
Formula for water requirement in hypernatremia
Water requirement = (desired change in Na+ over 1 day x TBW) / desired Na+ after giving the water requirement
For a 70 kg man with Na 165 = (16 x 42)/149 = 4.5 L
In hypernatremia change Na at ____ mEq/h
0.7
Sx of hyponatremia
headaches, delirium, seizures, nausea, vomiting
Formula for Na deficit in hyponatremia
Na deficit = 0.6 x weight in kg x (140 - Na)
What is the first tx for hyponatremia? second? third?
water restriction, diuresis, NaCl replacement
Why is Na corrected slowly In hyponatremia and what is the rate?
avoid central pontine myelinosis, 1 mEq/h
What is the formula for correcting Na in pseudohyponatremia caused by hyperglycemia?
for each 100 increment of glucose over normal add 2 points to the Na value
What is the normal Ca range?
8.5-10.0
Most common malignant cause of hypercalcemia?
breast CA
What drug causes retention of Ca2+ and should not be given to patient with hypercalcemia?
thiazides (also LR contains Ca2+)
What is the tx for hypercalcemia?
For malignant disease?
NS at 200-300 cc/hr, Lasix
mithramycin, calcitonin, alendronic acid, dialysis
Main sx of hypercalcemia?
lethargic state
Sx of hypocalcemia?
hyperreflexia, Chvotstek’s sign (tapping on face produces twitching), perioral tingling and numbness, Trousseau’s sign (carpopedal spasm), prolonged QT
In hypocalcemia, may need to correct ___ before being able to correct Ca
Mg
Protein adjustment for Ca
For every 1g decrease in protein, add 0.8 to Ca
Normal range of Mg
2.0-2.7
Sx of hypermagnesemia? What type of pts?
lethargic state
burn, trauma and dialysis pts
Tx for hypermagnesmia
Ca
Signs and sx of hypomagnesmia are similar to what?
hypocalcemia
Formula for anion gap and normal range
Na - (HCO3 + Cl)
Less than 10-15
Mnemonic for anion gap acidosis
MUDPILES
methanol, uremia, diabetic ketoacidosis, paraldehydes, isoniazid, lactic acidosis, ethylene glycol, salicylates
Normal gap acidosis usually due to loss of ____/____
Seen with?
Na/HCO3
ileostomies, small bowel fistulas
Tx for metabolic acidosis is underlying cause; keep pH > ___ with bacarbonate; severely decreased pH can affect ____
7.20, myocardial contractility
Metabolic alkalosis is usually the result of ____
contraction alkalosis
Nasogastric suction results in what electrolyte abnormality and what is the urine?
hypocholoremic, hypokalemic, metabolic alkalosis
paradoxical aciduria
Why is there hypokalemia in nasogastric suction?
and why is there paradoxical aciduria?
Loss of water causes kidney to resorb Na in exchange for K (Na/K ATPase)
Na+/H- exchange activated in an effort to absorb water along with K+/H- exchanger in an effort to resorb K+
Henderson-Hesselbach equation
pH = pK + log [HCO3-]/[CO2]
A pH of 7.4 has a ratio of base to acid (HCO3- to CO2) of ____
20:1
What is the best test for azotemia?
FeNa
What is the formula for FeNa
(urine Na/Cr)/(plasma Na/Cr)
In Pre renal failure. What is the FeNa? urine Na? BUN/Cr ratio? urine osmolality?
FeNa less than 1%, urine Na less than 20, BUN/Cr >20
urine osmolality >500 mOsm
In contrast dye induced ARF: What best prevents renal damage? What are 2 others?
volume expansion, HCO3-, N-acetylcysteine gtt
Myoglobin is converted to ____ in acidic environment which is toxic to renal cells. Tx?
ferrihemate, alkalinize urine
In tumor lysis syndrome there is increased ___ and ___ and decreased Ca. This can result in increased BUN and Cr, EKG changes. Tx?
phosphate and uric acid
hydration, allopurinol (decreased uric acid production), diuretics, alkalinization of urine
5% dextrose will stimulate ___, resulting in amino acid uptake and protein synthesis (also prevents protein catabolism)
Insulin
Which bodily fluid has the highest concentration of Cl-
Stomach
Which bodily fluid has the highest concentration of HCO3
Pancreas
IVF of choice for patients with closed head injuries
Hypertonic saline
% renal mass damage to result in an increase in creatinine and BUN
70%
