E3 acids and bases (very light version) Flashcards
normal pH
7.35-7.45
pH is regulated by balance of what and what
bicarb and co2
primary buffer in the blood
bicarb
kidneys reabsorb?
bicarb
kidneys excrete?
H+
kidneys generate?
new bicarb
lungs regulate?
CO2 levels by adjusting ventilation
liver affects bicarb through?
protein metabolism
lungs compensation mechanism
adjusting CO2
metabolic or respiratory:
lungs compensation mechanism
metabolic
kidney compensation mechanism
altering bicarb reabsorption or H+ excretion
metabolic or respiratory:
kidney compensation mechanism
respiratory
low pH and low bicarb
metabolic acidosis
non-anion gap metabolic acidosis due to?
bicarb loss (diarrhea, renal tubule acidosis)
anion gap metabolic acidosis due to?
accumulation of acids (lactic acidosis, ketoacidosis, toxic ingestion)
pH where we want to treat with bicarb
<7.1
high pH, high bicarb
metabolic alkalosis
saline-responsive metabolic alkalosis often due to?
volume depletion (vomiting, diuretics)
saline responsive metabolic alkalosis responds to ___ or ____
sodium chloride
potassium chloride
treatment for metabolic alkalosis
consider carbonic anhydrase inhibitors (acetazolamide if fluid restriction is needed)
low pH, high CO2
respiratory acidosis
respiratory acidosis causes
hypoventilation from lung disease
cns depression
neuromucular disorders
high pH, low CO2
respiratory alkalosis
causes of respiratory alkalosis
hyperventilation from anxiety, pain, hypoxemia, or high altitude
3 main things to look at to determine metabolic or respiratory
pH, bicarb, PaCO2
Which of the following is the primary buffer system in the blood?
A. Phosphate buffer
B. Bicarbonate buffer
C. Protein buffer
D. Ammonia buffer
B
A patient with chronic kidney disease presents with a pH of 7.31 and HCO3- of 18 mEq/L. What type of acid-base imbalance is most likely?
A. Respiratory acidosis
B. Metabolic alkalosis
C. Metabolic acidosis
D. Respiratory alkalosis
C
Which compensation mechanism would be expected in a patient with metabolic alkalosis?
A. Increased renal H+ excretion
B. Decreased renal HCO3- reabsorption
C. Hypoventilation to retain CO2
D. Hyperventilation to expel CO2
C
What is a common cause of non-anion gap metabolic acidosis?
A. Lactic acidosis
B. Diabetic ketoacidosis
C. Diarrhea
D. Salicylate toxicity
C
Which condition is most likely to cause respiratory alkalosis?
A. Anxiety
B. Chronic obstructive pulmonary disease (COPD)
C. Severe vomiting
D. Renal failure
A
An anion gap metabolic acidosis with a high lactate level is most often associated with which condition?
A. Hyperventilation
B. Liver failure
C. Hypoxemia or shock
D. Salicylate overdose
C
A patient with hypokalemia and metabolic alkalosis is found to have a urinary chloride of 15 mEq/L. Which type of alkalosis is this most consistent with?
A. Saline-responsive alkalosis
B. Saline-resistant alkalosis
C. Respiratory alkalosis
D. Mixed acid-base disorder
A
In which scenario would you consider bicarbonate therapy for metabolic acidosis?
A. pH of 7.35 with normal HCO3- levels
B. pH of 7.50 with low PaCO2
C. pH < 7.10, particularly if the patient has hyperkalemia or is in cardiac arrest
D. pH of 7.25 with a normal anion gap
C
Which of the following is an appropriate first-line treatment for respiratory acidosis due to opioid overdose?
A. Sodium bicarbonate infusion
B. Naloxone administration
C. Mechanical hyperventilation
D. Administration of K+ supplements
B
A patient on mechanical ventilation has a pH of 7.49, PaCO2 of 25 mmHg, and HCO3- of 19 mEq/L. Which of the following acid-base disorders is most likely?
A. Metabolic alkalosis
B. Respiratory alkalosis
C. Mixed acidosis
D. Respiratory acidosis
B
PaCO2 range
35-45 mmHg, use 40 for calculations
bicarb range
22-26 mEq/L, use 24 for calculations
anion gap formula
Na - (bicarb+Cl) (use the serum bicarb if given)
anion gap range
3-11, use 10 for calculations
when do you calculate delta gap?
when anion gap is above normal range
delta gap formula
pt anion gap - normal anion gap (we use 10)
adjusted bicarb formula
pt bicarb + pt delta gap
if adjusted bicarb is within normal range (22-26) what does this mean?
pure anion gap metabolic acidosis with no additional metabolic disorder
if adjusted bicarb is above the normal range (>26) what does this mean
indicates a mixed disorder with both an anion gap metabolic acidosis and a concurrent metabolic alkalosis
if adjusted bicarb is below normal range (<22) what does it mean?
a mixed disorder with an anion gap metabolic acidosis and a concurrent non-anion gap metabolic acidosis
MUDPILES
methanol
uremia
diabetes (ketoacidosis)
paraldehyde (propylene glycol)
isoniazid, iron overdose
lactic acidosis
ethylene glycol
salicylates (aspirin overdose)
mudslip used to remember causes of?
anion gap metabolic acidosis
HARDUPS
-Hyperalimentation (TPN w/ Cl-containing solutions
- Acetazolamide
- Renal tubular acidosis
- Diarrhea
- Ureteral diversion
- pancreatic fistula
- saline infusion
hardups used to remember causes of?
non-anion gap metabolic acidosis
shock is likely the reason for?
metabolic acidosis
lactic acidosis
formula to determine what dose of bicarb to give when pH is <7.1
(0.5L/kg x IBW) x (desired bicarb - actual bicarb)
desired is usually set to 12
after calculating the dose of bicarb you will be giving, what to do you make sure you do? ****
give 1/3 to 1/2 initially “she said this was an exam question so”
blood transfusions can increase the risk of?
metabolic alkalosis
