Acid Base Balance Flashcards
What cause respiratory acidosis?
Anything that lead to (alveolar hypoventilation)
- primary pulmonary disease
- Neuromuscular disease
- CNS malfunction
- drug induced
- respiratory muscle fatigue
What cause respiratory alkalosis?
Anything that lead to alveolar hyperventilation
- sepsis
- hypoxia “low tidal volume > tachypnea”
- mechanical ventilation
- liver disease “stage 2 - 3”
- hyperventilation syndrome
What are the steps in acid base analysis?
- primary disturbance
- acute or chronic?
- anion gap
- compensation
What are the values of metabolic, respiratory acidoses
PH <7.35
- respiratory: both HCO3 + PCO2 high
- metabolic: both HCO3 + PCO2 low
What are the values of metabolic, respiratory alkalosis?
PH >7.35
- respiratory: both HCO3 + PCO2 low
- metabolic: both HCO3 + PCO2 high
How to determine acute vs chronic respiratory acidosis disorder
Increment is always 10.
- PH: 0.3 in chronic - 0.8 in acute
- HCO3: 4 in chronic - 1 in acute.
How to determine acute vs chronic respiratory alkalosis disorder
Increment is always 10.
- PH: 0.3 in chronic - 0.8 in acute
- HCO3: 5 in chronic - 2 in acute.
What causes increase in anion gap?
- lactic acid
- ketoacid
- renal failure
- salicylate toxicity
What causes normal anion gap?
- tubular acidosis
- hypercholermia
- diarrhea & fistula
Appropriate compensation of metabolic acidosis
Winter’s formula
- PCO2: 1.5[HCO3] + 8 (+-) 2
If it’s more than the normal range
Then it’s mixed condition
Differentiate between saline-sensitive and saline resistant metabolic alkalosis management:
If saline resistant: don’t give volume, only treat the cause
If saline sensitive: give volume
What is saline sensitive and saline resistant characterized of
- sensitive: Hypokalemia + ECF contraction
- resistant: hypertension + ECF expansion
What are the causes of saline resistant and saline sensitive metabolic alkalosis?
Sensitive: Vomiting - NG suction - over-diuretic - post hypercapnia
Resistant:
- hypertensive (Cushing, conns, RAS, renal failure)
- non hypertensive (hypokalemia, hypomagnesemia, batter’s, gittelman, licorice ingestion)
- exogenous steroid.
What is the value of CL to determine saline resistant vs sensitive?
Cl >10 = resistant.
what is winter formula, and why do we do it?
To assess if there’s another type of acidosis
PCO2= 1.5 [HCO3] +8 +-2
