Editing Anatomy and Physiology (section)

=== Acid-Base ===

The lungs correct acid-base disturbance in minutes by changing carbon dioxide elimination; the kidneys correct over hours to days by handling hydrogen ion and bicarbonate.

A practical interpretation approach:
# Look at pH: below 7.35 is acidosis, above 7.45 is alkalosis.
# Look at PaCO2 (respiratory) and bicarbonate (metabolic).
# Whichever one moves in the same direction as the pH abnormality is the cause; if PaCO2 moves opposite to pH, the problem is respiratory, and if bicarbonate moves in the same direction as pH, the problem is metabolic.
# Check whether the other value has shifted to compensate.

Common causes: respiratory acidosis from hypoventilation (opioid oversedation, chronic obstructive pulmonary disease, atelectasis); respiratory alkalosis from hyperventilation (anxiety, pain, early sepsis); metabolic acidosis from diabetic ketoacidosis, shock and lactic acid, diarrhea, and kidney failure; metabolic alkalosis from vomiting, nasogastric suction, and excessive antacid intake.