Term
| What is the definition of an acid and a base? |
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Definition
An acid gives off hydrogen Ions: H2CO3 --> HC03
A base accepts hydrogen ions: HCO3 --> H2CO3 |
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Term
| What is the normal pH range of blood? |
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Definition
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Term
| What is the definition of an acidosis? |
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Definition
pH < 7.4
Can be either metabolic (low bicarbonate), or respiratory (high CO2) |
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Term
| What is the definition of an alkalosis? |
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Definition
pH > 7.4
Can be metabolic (high bicarbonate) or respiratory (low CO2) |
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Term
| What tool is used to assess Acid-base disorders? |
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Definition
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Term
| How is acid-base homeostasis regulated? |
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Definition
- Extracellular buffer - Carbonic acid to CO2 and carbonic acid to bicarb.
- Respiratory regulation - in acidosis, increased ventilation blows off CO2
- Renal regulation - bicarb freely filtered, ammonia makes new |
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Term
| What is metabolic acidosis? |
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Definition
| Decreased levels of bicarbonate lower pH, compensatory lowered levels of CO2. Usually due to buffering exogenous acids. Bicarbonate under 20, severe under 8. |
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Term
| What is metabolic alkalosis? |
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Definition
| Increase bicarbonate which increases pH. CO2 reflexively increases |
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Term
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Definition
Determines presence of organic acids
SAG = sodium - chlorine - bicarbonate
normal = 3 to 11
**Clinical pearl: Over 20 = primary metabolic acidosis REGARDLESS of pH or serum bicarb. |
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Term
| What are the causes of anion gap metabolic acidosis? |
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Definition
A - Aspirin
M - Methanol
U - Uremia
D - Diabetic ketoacidosis
P - paraldehyde
I - Infection/ischemia
E - Ethanol |
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Term
| What causes non-anion gap metabolic acidosis? |
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Definition
ACCRUED:
A - Ammonia chloride
C - Chloride
C - Cholestyramine
R - Renal tubular acidosis
U - Urine diverted to bowel
E - Endocrine disorder/addison's
D - Diarrhea |
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Term
| What causes respiratory acid-base disorders? |
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Definition
- Respiratory alkalosis - decreases CO2 caused by hyperventilation, anything that causes hypoxemia. Side effect of metabolic acidosis. As CO2 decreases, Bicarb compensates by decreasing
- Respiratory acidosis - increased CO2 due to hypoventilation, inhibition of respiration. As CO2 goes up, bicarb also goes up |
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Term
| How do you tell if a combined disorder exists? |
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Definition
| Always calculate compensatory CO2, see if it matches the patients. If not, a combined disorder exists |
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Term
| How is respiratory compensation calculated? |
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Definition
- Metabolic acidosis - PCO2 = 1.5*bicarb +8
- Metabolic alkalosis - 40 + 0.7(HCO3 measured - normal) |
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Term
| How does pCO2 determine metabolic alkalosis or respiratory acidosis? |
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Definition
- if >40 and pH is HIGH - metabolic alkalosis. < 40 = respiratory
- if >40 and pH is LOW - respiratory acidosis. <40 - metabolic |
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