What it means
The blood must stay between a pH of 7.35 and 7.45. Three systems keep it there: buffers in the blood act within seconds, the lungs change how much carbon dioxide (an acid) is breathed out within minutes, and the kidneys change how much acid and bicarbonate they keep or remove over hours to days. When one system fails, the others try to make up for it (compensation). An arterial blood gasar-TEER-ee-ul BLUD GASA blood test from an artery that measures oxygen, carbon dioxide, bicarbonate and the blood's pH.Full entry shows the balance.
For the nurse
Know the four main imbalances: respiratory acidosis and alkalosis (a lung problem, seen in the PaCO2) and metabolic acidosis and alkalosis (a kidney or body-chemistry problem, seen in the bicarbonate). Look at the client's breathing, mental status and potassium level, which shift with the pH.
At a glance
| Spanish | equilibrio ácido-base |
|---|---|
| Also written | acid-base balances, acid–base balance |
Related terms
arterial blood gas
A blood test from an artery that measures oxygen, carbon dioxide, bicarbonate and the blood's pH.
homeostasis
The body's way of keeping its inside conditions, such as temperature, fluids and blood sugar, steady.
respiratory alkalosis
An acid-base imbalance in which breathing out too much carbon dioxide makes the blood too alkaline.
PaO2
The partial pressure of oxygen in arterial blood: a measure of how much oxygen is dissolved in the blood, from an arterial blood gas.