NU448 Module 2 - Interpreting Arterial Blood GasValuesIntroductionThis section continues to provide information on acid-base imbalances in the body.Alterations in Acid-Base BalanceAn acid-base imbalance results when there is an alteration in the ratio of 20:1 between baseand acid content. This occurs when a disease or process alters one side of the ratio (e.g.,CO2retention in pulmonary disease) and the compensatory processes that maintain the otherside of the ratio (e.g., increased renal HCO3−reabsorption) either fail or are inadequate. Thecompensatory process may be inadequate because either the pathophysiologic process isoverwhelming or there is insufficient time for the compensatory process to work.•Acid-base imbalances are classified asrespiratoryormetabolic.Respiratory imbalancesresult from the retention or an excess of CO2altering carbonic acidconcentrations.Metabolic imbalancesaffect the base HCO3−.Acidosis occurs with an increase in carbonic acid (respiratory acidosis) or a decrease inHCO3−(metabolic acidosis).Alkalosis occurs with a decrease in carbonic acid (respiratory alkalosis) or an increase inHCO3−(metabolic alkalosis).Imbalances are further classified as acute or chronic. Chronic imbalances allow greater timefor compensatory changes.Respiratory AcidosisRespiratory acidosis(carbonic acid excess) occurs whenever the person hypo ventilates.Hypoventilation leadsto a buildup of CO2, resulting in an accumulation of carbonic acid in theblood.Carbonic acid dissociates, releasing H+and decreasing pH. If CO2is not eliminated from theblood, acidosis results from the accumulation of carbonic acid.
