| Breathing pattern | Metabolic pattern | pH, PaCO2, HCO3 | Specific conditions |
| Hyperventilation | Metabolic acidosis | pH <7.3, PaCO2 <30 mmHg, HCO3 <17 mmol/L | Uremia, diabetic ketoacidosis, lactic acidosis, salicylates, methanol, ethylene glycol. |
| Hyperventilation | Respiratory alkalosis | pH >7.45, PaCO2 <30 mmHg, HCO3 >17 mmol/L | Hepatic failure, acute sepsis, acute salicylate intoxication, cardiopulmonary states with hypoxemia, psychogenic causes. |
| Hypoventilation | Respiratory acidosis | pH <7.35 (if acute), PaCO2 >90 mmHg, HCO3 >17 mmol/L | Respiratory failure from central (eg, brain or spinal cord) or peripheral nervous system disease, chest conditions or deformities. Coma only with severe hypercarbia. |
| Hypoventilation | Metabolic alkalosis | pH >7.45, PaCO2 >45 mmHg, HCO3 >30 mmol/L | Vomiting, alkali ingestion. Usually no impairment of consciousness; if so, suspect psychogenic unresponsiveness or additional cause. |
