Respiratory Acid-Base Disorders Flashcards
Review: Normal pH, HCO3-, and pCO2?
pH: 7.4
HCO3-: 24 mEq/L
pCO2: 40 mmHg
What affect do hyperventilation and hypoventilation have on pCO2? On blood pH?
Hyperventilation: lowers pCO2, increases blood pH.
Hypoventilation: increases pCO2, lowers blood pH.
When pCO2 goes down, how will bicarb change?
If pCO2 drops, so will bicarb.
If pCO2 increases, so will bicarb.
How does acute vs. chronic bicarb compensation for changes in pCO2 compare?
The chronic compensation for pCO2 has a greater magnitude change in bicarb.
By approximately what magnitude does HCO3- change in acute decreased pCO2, per unit change in pCO2?
In chronic decreased pCO2?
Acute: HCO3- drops by 2 mEq/L for every 10 mmHg drop in pCO2.
Chronic: HCO3- drops by 5 mEq/L for every 10 mmHg drop in pCO2.
Signs/symptoms of respiratory alkalosis? (underlying pathophysiology?)
Parathesias, numbness, tetany (decreased Ca++, increased excitability).
Dizziness/confusion (cerebral vasospasm).
(as an aside, respiratory alkalosis can be promoted to induce a short term decrease in ICP)
What common pathophysiology underlies the respiratory alkalosis caused by both pregnancy and liver disease?
Increased estrogen.
By approximately what magnitude does HCO3- change in acute INCREASED pCO2, per unit change in pCO2?
In chronic INCREASED pCO2?
Acute: 1 mEq/L HCO3- increase per 10 mmHg pCO2.
Chronic: 3.5 mEq/L HCO3- increase per 10 mmHg pCO2.
Several problems associated with respiratory acidosis?
Confusion, obtundation.
Cerebral vasodilation -> increased ICP.
Formula for alveolar volume?
Alveolar volume = tidal volume - dead space
So… either decreased tidal volume or increased dead space will decrease alveolar volume. Pretty straightforward.
Things that slow breathing, such as an opiate overdose can cause respiratory acidosis.
Right.
(Review: Treatment for opiate overdose?)
(naloxone)
