If supplementation of oxygen is continued, the individual will notice tightness in the chest, difficulty breathing, shortness of breath, and if exposure is continued, fatality due to lack of oxygen. Cause
Oxygen supplied at greater than atmospheric pressure has been known to damage plants, animals, and aerobic bacteria such as Escherichia coli. The damaging effects vary depending on the specimen used, its age, physiological state, and diet.The supplementation of oxygen has been a common procedure of prehospital treatment for many years. Guidelines include cautions about chronic obstructive pulmonary disease (COPD). These guidelines stress the use of 28% oxygen masks and caution the dangers of hyperoxia. Long-term use of supplemental oxygen improves survival in patients with COPD, but can lead to lung injury.An additional cause of hyperoxia is related to underwater diving with breathing apparatus. Underwater divers breath a mixture of gasses which must include oxygen, and the partial pressure of any given gas mixture will increase with depth. A mixture known as nitrox is used to reduce the risk of decompression sickness by substituting oxygen for part of the nitrogen content. Breathing nitrox can lead to hyperoxia due to the high partial pressure of oxygen if used too deep or for too long. Protocols for the safe use of raised oxygen partial pressure in diving are well established and used routinely by recreational scuba divers, military combat divers and professional saturation divers alike.
The highest risk of hyperoxia is in hyperbaric oxygen therapy, where it is a high probability side effect of the treatment for more serious conditions, and is considered an acceptable risk as it can be managed effectively without apparent long term effects. Diagnosis
Treatment
Oxygen supplementation is used to treat tissue hypoxia and to relieve arterial hypoxemia. High concentrations of oxygen are often given to patients with chronic obstructive pulmonary disease (COPD) or acute lung injury (ALI). Supplementing oxygen is known to cause tissue damage, with toxicity increasing with the increase of oxygen concentrations and exposure pressures. Unfortunately, the supplementation of oxygen is necessary if an individual is not able to obtain sufficient oxygen through respiration and perfusion. To decrease the chances of hyperoxia, the therapist should use the lowest concentration of oxygen required by an individual. At this time, there are no known alternatives to oxygen supplementation. See also
Hypoxia – Medical condition caused by lack of oxygen in the tissues
Hypoxemia – Abnormally low level of oxygen in the blood
Oxygen toxicity – Toxic effects of breathing in oxygen at high concentrations
Hyperbaric medicine – Medical treatment at raised ambient pressure


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