Med Surg Exam 2 Flashcards
Normal pH
7.35-7.45
Acidosis
<7.35
Alkalosis
> 7.45
What do bases bind with?
Free H+ ions
What is a buffer?
any mechanism that resists changes in pH by converting a strong acid or base to a weak acid or base
What are some examples of chemical buffers?
ammonia
phosphates
carbonic acid-sodium bicarbonate system
What is the most active buffer system?
Carbonic acid-sodium bicarbonate system
How do you keep acids in balance with bases?
acids must be neutralized and excreted
What are two neutralizers?
CO2 (acid) and HCO3 (base) are neutralizers
What is normal acid base balance?
20 bicarbonate ions (HCO3) to 1 carbonic acid (H2CO3)
What must be controlled to maintain the acid base balance ratio?
Both bicarbonate ions and carbonic acid must be controlled.
How is CO2 continuously formed?
intracellular metabolic processes (cellular respiration)
Increased respiration means? (resp. compensation)
More CO2 produced
Decreased respiration means?(resp. compensation)
Less CO2 produced
How quickly does respiratory compensation occur?
within minutes (to preserve acid base balance)
How does the respiratory system regulate H+ concentration?
CO2 excretion (exhalation) CO2 retention (to prevent alkalosis)
How does the renal system help acid base balance?
Excrete H+ ions
Reabsorbs (conserves) bicarbonate
Forms new bicarb (carbonic acid loses H+ ions)
What is the carbonic acid disassociation formula?
CO2 + H2O↔️H2CO3↔️H+HCO3
How do the kidneys compensate in acidosis?
excreting H+ (K+ stays) “If you’re staying, I’m outta here”
retains bicarb
How do the kidneys compensate in alkalosis?
saves H+ (K+ goes) “i’m staying, get outta here”
excretes bicarb
Is renal compensation a stronger or weaker mechanism than respiratory compensation?
Stronger. It takes longer to respond 24-48 hours.
When is renal compensation fully stimulated?
When the Acid/Base imbalance lasts for several hours or several days
What causes respiratory acidosis?
Accumulation of CO2
COPD with CO2 retention (cant blow off co2)
Hypoventilation due to: sedation, overdose, anesthesia, change in LOC Closed head injury CVA
What are signs of respiratory acidosis?
headache, confusion, drowsiness, dyspnea, muscle weakness, elevated blood K+