Acid-Base Flashcards
what are you assessing when you look at pH and PCO2?
ventilation
What are you assessing when you look at PaO2 and SaO2?
oxygenation
acidosis
low serum bicarbonate
acidemia
serum pH <7.35
alkalosis
high serum bicarbonate
alkalemia
serum pH > 7.45
What is the purpose of the oxyhemoglobin dissociation curve?
tool used to show the relationship between oxygen saturation and the PaO2
What happens to shift the oxyhemoglobin dissociation curve to the left?
decreased H+, decreased CO2, decreased temp
What happens to shift the oxyhemoglobin dissociation curve to the right?
increased H+, increased CO2, increased temp
Hendersen-Hesselbach Equation
H2CO3 = H + HCO3 = H2O + CO2
What do the kidneys remove in response to pH changes?
metabolic acids, bicarbonate, lactic acid, ketones, phosphoric acid
Pneumonics for underlying causes of anion gap and non AG metabolic acidosis
AG- MUDPILES. Non AG- USED CAR
anion gap calculation
( Na + K) - ( Cl + HCO3). Normal AG is 3-11
what is ureteral-sigmoid diversion?
accumulate urine in intestine, reabsorb Cl / H20 in intestine, secrete bicarb in intestine
winter’s formula
used to calculate respiratory compensation for metabolic acidosis. PCO2=1.5x ( HCO3 +8 )
summer’s formula
used to calculate respiratory compensation for metabolic alkalosis. PCO2=0.7 ( HCO3+21)
how do you calculate delta anion gap?
Anion Gap – ( normal Gap (12))
how do you calculate delta bicarb?
Measured bicarbonate – normal bicarb
how do you determine if there’s a triple ripple?
If delta AG > delta BC then there is also metabolic alkalosis. If delta AG < delta BC then non- AG acidosis is also present.
what is posthypercapnic alkalosis?
rapid lowering of chronically elevated PCO2 (usually by mechanical ventilation) resulting in metabolic alkalosis. Raises the cerebral intracellur pH
What is an important test you should perform before messing with radial artery?
Allen’s Test
Symptoms of alkalosis
paresthesias, tetany, seizures
What is contraction alkalosis?
Loss of large volumes of fluid. Contraction of extracellular volume around relatively constant quantity of bicarbonate
Which of the following are causes of contraction alkalosis: IV loop diuretics, thiazides, vomiting, sweat losses in CF pts?
all are causes of contraction alkalosis
what can cause renal H+ loss?
excess aldosterone
At what urine chloride levels will respond to saline treatment?
levels that are < 10mEq/L
How many units of blood are needed before you’re likely to see metabolic alkalosis due to the citrate that’s infused with the blood?
8 or more units of blood
