| Hypoxia | Hyperoxia | |||
| Effects | Risks | Effects | Risks | |
| Respiratory system | Increased ventilationPulmonary vasoconstriction | Pulmonary hypertension | Decreased ventilation (minimal) | Worsened ventilation/perfusion matchingAbsorption atelectasis |
| Cardiovascular system | Coronary vasodilationDecreased systemic vascular resistance (transient) Increased cardiac outputTachycardia | Myocardial ischaemia/infarctionIschaemia/infarction of other critically perfused organsHypotensionArrhythmias | Myocardial ischaemia (in context of decreased haematocrit) Reduced cardiac outputReduced coronary blood flowIncreased blood pressureIncreased peripheral resistance | |
| Metabolic system | Increased 2,3-DPGIncreased CO2 carriage (Haldane effect) | Lactic acidosis | Decreased 2,3-DPGDecreased CO2 carriage (Haldane effect) | Increased reactive oxygen species |
| Neurological system | Increased cerebral blood flow due to vasodilation | ConfusionDeliriumComa | Decreased cerebral blood flow | |
| Renal system | Renin-angiotensin axis activation | Acute tubular necrosis | Reduced renal blood flow | |
| Increased erythropoietin production | ||||
2,3-DPG, 2,3-diphosphoglycerate.