Acid-Base D/O Flashcards
What is the normal pH range of human blood?
7.35 to 7.45
True or False: Acidosis refers to a condition where blood pH is below 7.35.
True
What is the primary organ responsible for acid-base regulation?
Kidneys
1) normal h+ ion concentration in nmol/L & pH?
2) acidemia
3) alkalemia
1) 40 nmol/L (7.4 pH)
2) increased h+ ions, <7.35 pH
3) decreased h+ ions, >7.45 pH
What is the primary extracellular buffer system in the blood?
Bicarbonate buffer system
True or False: The lungs can regulate blood pH by changing the rate of carbon dioxide exhalation.
True
What is metabolic acidosis?
A condition characterized by a decrease in blood pH due to increased acid or loss of bicarbonate.
Multiple Choice: Which of the following conditions can lead to respiratory acidosis? (A) Hyperventilation (B) COPD (C) Metabolic alkalosis
B) COPD
What is the role of the kidneys in acid-base balance?
The kidneys excrete hydrogen ions and reabsorb bicarbonate.
Fill in the blank: An increase in carbon dioxide levels in the blood causes a __________ in pH.
decrease
True or False: Respiratory alkalosis occurs when there is an excess of carbon dioxide in the blood.
False
What is the compensatory mechanism for metabolic acidosis?
Increased respiratory rate to exhale more CO2.
Multiple Choice: Which of the following is NOT a cause of metabolic alkalosis?
(A) Vomiting (B) Diarrhea (C) Diuretics
B) Diarrhea
What is the effect of hyperventilation on blood pH?
It increases pH, leading to respiratory alkalosis.
Fill in the blank: A high anion gap indicates __________ acidosis.
metabolic
True or False: The body can tolerate a wide range of pH levels without severe consequences.
False
What is the primary effect of acidosis on the body’s functions?
It can impair enzyme activity and disrupt cellular functions.
Multiple Choice: Which of the following is a clinical manifestation of acidosis? (A) Confusion (B) Hyperactivity (C) Hypertension
A) Confusion
What does the term ‘compensation’ refer to in acid-base regulation?
The body’s physiological response to restore normal pH.
Fill in the blank: The __________ is the primary organ for excreting hydrogen ions.
kidney
What is the difference between metabolic acidosis and respiratory acidosis?
Metabolic acidosis is due to excess acid or loss of bicarbonate, while respiratory acidosis is due to CO2 retention.
True or False: Bicarbonate can be administered to treat acidosis.
True
What laboratory test is commonly used to assess acid-base status? Where do you typically obtain the sample from?
Arterial blood gas (ABG) analysis (assesses gas exchange (ventilation) and acid-base disturbances)
- radial artery
Standard result reference ranges:
1) pH
2) pCO2
3) HCO3
4) Na+
1) 7.35-7.45 pH
2) 35-45 pCO2
3) 22-26 mEq/L HCO3
3) 135-145 mEq/L
Venous Blood Gas (VBG) measures what gases?
what can it NOT accurately measure?
similar to ABG (pH, pCO2, HCO3)
- it cannot accurately measure OXYGENATION
What is the Henderson Hasselbach equation?
pH = 6.1 log (HCO3/(0.03 X pCO2))
Is CO2 Acidic or basic?
As respiration is increased, what happens to CO2?
Acidic
it decreases (blown off)
1) Conditions resulting in Alkalotic blood?
2) Condition resulting in Acidosis blood?
1) Hypocapnia, Hypocarbia, Alkalosis
2) Hypercapnia, Hypercarbia, Acidosis
What gas is the RESPIRATORY component of acid-base determination?
What gas is the METABOLIC (renal) component of acid-base determination?
- CO2 (respiratory)
- HCO3- (metabolic - renal)
Bicarb < 22 is called?
Bicarb >26 is called?
Is bicarb an acid or base?
- Acidosis
- Alkalosis
- Base
How is base excess/deficit calculated?
Base Excess = ?
An Excess is a primary or prolonged compensation for what?
Base Deficit = ?
1) using pH, pCO2, and hematocrit
2) Metabolic alkalosis
3) compensation for Respiratory acidosis
4) Metabolic acidosis
What does the pO2 represent?
What does the O2 saturation measure?
What is the O2 content?
1) the force needed for O2 to diffuse across alveolar membrane
2) % of hemoglobin saturated with O2
3) total amount of O2 in the blood
What 3 things can cause a decrease in pO2 and O2 content?
a) difficulty diffusing across the membrane in the lung as with pneumonia
b) premature mixing of venous and arterial blood as in congenital heart disease
c) underventilation or under perfused alveoli in the lungs as in significant atelectasis, obesity-hypoventilation syndrome
What does the Alveolar (A) to arterial (a) gradient reflect?
A HIGH A-a gradient can tell what 2 things?
1) the difference between alveolar and arterial O2
2a) problem diffusing O2 across alveolar membrane in lungs (ex. thickened edematous alveoli)
2b) unoxygenated blood prematurely mixing with oxygenated blood
Define the anion gap (AG)?
Equation?
What is the normal AG range? what is high?
1) difference between measured cations and measured anions in the extracellular space (UNMEASURED anions)
2) Na - (Cl+HCO3)
3) 6-12 mEq/L; >12 is high
How is the anion gap increased and decreased?
INCREASED with the accumulation of acidic anions (Lactate, acetoacetate)
DECREASED with BICARB as it neutralizes acidic metabolic byproducts as they accumulate in the blood
What are Anionic plasma proteins that are not measured?
Albumin, phosphates, sulfates, organic anions
An AG >12 = ?
an AG 12 and less = ?
A higher AG is mostly related to what?
1) HIGH anion gap Metabolic acidosis
2) NORMAL anion gap metabolic acidosis
3) organic blood acids that the body is producing too much of
What unmeasured anion is primarily responsible for the AG?
Review equation slide17
albumin
What are the 4 primary Acid-base disorders?
Respiratory
- Acidosis (acute <3 d and chronic 3+ d)
- Alkalosis (acute and chronic)
Metabolic
-Acidosis (NAGMA, HAGMA)
-Alkalosis
How do acid base disorders compensate?
Which is faster?
respiratory (through pCO2) will compensate metabolic (via kidneys HCO3) and vice versa
- Respiratory is faster
Practice charts slide 20 and 21
When should MIXED acid-base disorders be suspected?
1) inadequate or exaggerated compensatory response
2) changes in pCO2 and HCO3 are in OPPOSITE directions
3) no change in pH yet significant change in pCO2 and HCO3
4) Metabolic acidosis with certain (delta) AG/HCO3 ratios
