Acid-Base Balance Flashcards
Normal pH is…
7.4
Range of 7.35 to 7.45
Acid-base disturbances are associated with…
Significant morbidity and mortality
If pH is less than 7.4, the patient is in…
Acidosis
If pH is above 7.4, the patient is in…
Alkalosis
These organs are primarily responsible for maintaining acid-base homeostasis…
Lungs and kidneys
The lungs regulate pH via ____, which is…
Carbon dioxide - acidic
The kidneys regulate pH via ____, which is…
Bicarbonate - basic
The lungs adjust ____ to…
CO2 - increase/decrease PaCO2 based on pH
The lungs are able to make adjustments to PaCO2…
Relatively quickly within minutes - via respiratory rate
The kidneys adjust ____ to…
Bicarbonate excretion - increase/decrease bicarb levels based on pH
Compared to lung speed, the kidneys response to acid-base changes…
Is slower - days
Metabolic acidosis is defined by…
pH below 7.4
Decreased serum bicarbonate
Compensation for metabolic acidosis is…
Respiratory - decrease PaCO2
Metabolic acidosis may be due to…
Accumulation of acidic anions (lactic acidosis)
Disturbance of endogenous H+/HCO3-
Treatment of metabolic acidosis is primarily…
Identifying + correcting cause
Bicarbonate administration
Metabolic alkalosis is defined by…
pH above 7.4 & elevated serum bicarbonate
Most common causes of metabolic alkalosis include…
Loss of gastric acid due to vomiting
Loss of intravascular volume/chloride due to diuretics
Iatrogenic - improper anion balance in parenteral nutrition, or overcorrection of metabolic acidosis with bicarbonate
Treatment of metabolic alkalosis is…
To correct underlying factors
Volume repletion with norma saline
Carbonic anhydrase inhibitors - increase serum carbonic acid levels
Respiratory alkalosis is defined as…
pH above 7.4 and decreased PaCO2
If respiratory alkalosis is acute, serum bicarbonate…
Will still be normal (metabolic compensation occurs slowly)
If respiratory alkalosis is chronic, serum bicarbonate…
Will be decreased to compensate
Respiratory alkalosis occurs physiologically in…
Pregnancy
Individuals living at high altitudes
However commonly seen in hospitalized patients
Most common causes of respiratory alkalosis include…
Central stimulation of respiration (anxiety, pain)
Hypoxemia or tissue hypoxemia
Peripheral stimulation of respiration
Respiratory alkalosis is treated by…
Identifying and correcting the underlying cause
Respiratory acidosis is defined by…
pH below 7.4, and increased PaCO2
If respiratory acidosis is acute, serum bicarbonate…
Will still be normal
If respiratory acidosis is chronic, serum bicarbonate…
Will be increased to compensate
Causes of acute respiratory acidosis may be from…
Central (drugs, infection, stroke)
Perfusion abnormalities
Airway and pulmonary abnormalities
Chronic, compensated respiratory acidosis may not require…
Treatment
Acute respiratory acidosis treatment focuses on…
Increasing tissue oxygenation to address severe hypoxia
Treating underlying causes
