ch 4 understanding acid-base disorders

respiratory acidosis

excess carbon dioxide retention

respiratory acidosis ABG findings

pH <7.35

HCO3- > 26 mEq/L (if compensating)

PaCO2 > 45 mm Hg

respiratory acidosis possible causes

cns depression from drugs, injury, or disease, causing hypoventilation

asphyxia

hypoventilation from pulmonary, cardiac, musculoskeletal, or neuromuscular disease

respiratory alkalosis

excess CO2 excretion

respiratory alkalosis ABG findings

pH > 7.45

HCO3- < 22 mEq/L (if compensating)

PaCO2 < 35 mm Hg

respiratory alkalosis possible causes

hyperventilation from anxiety, pain, or improper ventilator settings

respiratory stimulation due to drugs, disease, hypoxia, or fever

metabolic acidosis

bicarbonate loss and acid retention

metabolic acidosis ABG findings

pH < 7.35

HCO3- < 22 mEq/L

PaCO2 < 35 mm Hg (if compensating)

metabolic acidosis possible causes

bicarbonate depletion from diarrhea

excess production of organic acids from diabetic ketoacidosis, hepatic disease, endocrine disorders, shock, or drug intoxication

inadequate excretion of acids from renal disease

metabolic alkalosis

HCO3- retention

acid loss

metabolic alkalosis ABG findings

pH > 7.45

HCO3- > 26 mEq/L

PaCO2 > 45 mm Hg (if compensating)

metabolic alkalosis possible causes

loss of hydrochloric acid from prolonged vomiting or gastric suctioning

loss of potassium from increased renal excretion (as in diuretic therapy) or steroids

excessive alkali ingestion (toxicity)