Oxygen therapy

In humans, uptake of environmental oxygen via the lungs provides necessary substrates for energy production. This is a key ingredient to survival. Aerobic respiration is the most efficient mechanism for adenosine triphosphate (ATP) production by oxidative phosphorylation and serves as the fuel to maintain cellular homeostasis and metabolism. Absence or lack of ATP leads to loss of cellular integrity initially, followed by
cellular and later organism death. Under hypoxic conditions, ATP production is inefficient (through glycolysis) and leads to production of lactic acid. A substantial part of critical care is targeted at treating and/ or preventing hypoxia, yet in recent years the risks of hyperoxia leading to organ damage have become better understood. Thus an understanding of the common pathways and significance of cellular hypoxia is vital
to providing appropriate and safe support and treatment to the acutely unwell patient.