Acid/Base Case Studies

Respiratory Alkalosis

Arterial blood pCO2 falls below 35 mmHg

metabolic acidosis

HCO3- concentration drops below 22 mEq/L

Alkalosis

blood pH above 7.45

Acidosis

blood pH below 7.35

Metabolic acidosis and alkalosis occurs due to what

changes in the HCO3- conc. Normal range: 22-26 mEq/L in arterial blood

Respiratory acidosis and alkalosis occurs due to what

changes in the partial pressure of CO2 in blood. Normal range: 35-45 mmHg

metabolic compensation of respiratory alkalosis

decrease the excretion of H+ and decrease reabsorption of HCO3- -goal: increase lvl of CO 2 in the body

Respiratory Acidosis

elevation of pCO2 of arterial blood above 45mmHg -inadequate exhalation of CO2 causes the blood pH to drop

metabolic compensation of respiratory acidosis

goal for treatment is to increase the exhalation of CO2

Respiratory compensation of metabolic alkalosis

hypoventilation may bring blood pH into the normal range -treatment: consists of fluid therapy to correct chloride, potassium and other electrolyte deficiencies and correcting the cause of alkalosis

Metabolic compensation

if an individual has an altered pH due to respiratory causes, renal mechanisms (primarily changes in secretion of H+ and reabsorption of HCO3-) can help compensate for the alteration

complete compensation

if pH is brought within normal range

partial compensation

if pH is still lower than 7.35 or higher than 7.45

Respiratory compensation of metabolic acidosis

if problem is not too severe, hyperventilation can help bring blood pH into normal range -treatment: IV solutions of sodium bicarbonate and correcting the cause of acidosis

respiratory compensation

if the pH is altered due to metabolic causes, HYPERVENTILATION or HYPOVENTILATION can help bring blood pH towards the normal range

Normal range of systemic arterial blood

pH: 7.35-7.45

Metabolic Alkalosis

the blood HCO3- concentration is above 26 mEq/L -causes pH to increase to above 7.45

compensation

the physiological response to acid base imbalance that attempts to normalize arterial blood pH