acid-base balance Flashcards
acid-base balance
keeping pH between 7.35-7.45
importance of maintaining this balance
maintain homeostasis; good cellular function, good electrolyte balance, and good enzyme activity
acidosis
loss of bicarbonate; pH of 7.35 or lower
alkalosis
overabundance of bicarbonate; pH level of 7.45 or higher
pH changes that occur with metabolic acidosis
decrease in bicarbonate (HCO3); increased production and retention of acidic compounds
example: kidney failure, pyometra, diabetes, diarrhea
treatment: sodium bicarbonate, LRS, normosol R, plasmalyte 146, treat underlying condition
pH changes that occur with respiratory acidosis
increase in carbonic acid; increased CO2 retention
example: disruption in normal lung function - pneumothorax
treatment: (remove CO2) IPPV, reduce anesthetic level, reduce surgery time, treat primary lung disease if indicated
pH changes that occur with metabolic alkalosis
increase in bicarbonate (HCO3)
example: vomiting, iatrogenic (too much bicarbonate administered)
treatment: correct underlying cause, give NaCl (fluids)
pH changes that occur with respiratory alkalosis
decrease in carbonic acid
example: hyperventilation (pain, fever, excitement, toxemia, IPPV)
treatment: correct underlying cause of hyperventilation
3 methods for regulating acid-base balance
- buffering - quick acting (H+ acceptor/donator)
- lungs - moderately quick acting (retaining and excreting CO2)
- kidneys - slow acting (retaining and excreting HCO3)
parameters of blood gas analysis
◦ pH
◦ PaCO2 – partial pressure of CO2 dissolved in arterial blood
◦ PaO2 – partial pressure of O2 dissolved in arterial blood
◦ HCO3- - Bicarbonate in blood
◦ BE – Base excess (or deficit). The amount of base that needs to be added or subtracted in order to normalize the pH when PaCO2 is normal
PaCO2
partial pressure of CO2 in the arterial blood; indicates effectiveness of ventilation
increased CO2- respiratory acidosis
decreased CO2- respiratory alkalosis
PaO2
partial pressure of O2 in arterial blood; indicates the body’s ability to pick up O2
SaO2
percentage of hemoglobin carrying oxygen
SpO2
indirect measurement of (oxygen) hemoglobin carrying oxygen