Oxygen toxicosis

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Paul Bert , who first described oxygen toxicosis in 1878

Under an oxygen poisoning ( oxygen toxicity ) refers to the damaging effect of high concentrations of oxygen in the breathing air on the body. These occur primarily under increased pressure, but also over a longer period of time at normal pressure, if the partial pressure ( partial pressure ) of the oxygen is increased due to the absence of other gases.

root cause

The disease occurs primarily in the context of intensive medical positive pressure ventilation or when scuba diving with compressed air at a depth of 57 m or more at an ambient pressure of around 6.7 bar and a partial pressure between 1.4 bar and 1.6 bar. The oxygen radicals released during this process lead to symptoms in the central nervous system, lungs and eyes after the antioxidant systems have been exhausted.

In the space has been and is partially pure oxygen atmosphere used ( Gemini program , Apollo program , extra-vehicular ), but under reduced pressure, which showed no toxic effects for several days application bar to 0.65. The normal air pressure is around 1 bar (100 kPa) and the oxygen partial pressure ( p O 2 ) around 0.21 bar (21 kPa).

Clinical manifestations

Paul Bert Effect

If you breathe a gas mixture with an increased proportion of oxygen while the lungs are functioning, the arterial oxygen partial pressure ( p O 2 ) increases. In the short term, this leads to central nervous symptoms, which are known as the Paul Bert effect. These are tunnel vision , ringing in the ears , nausea, dizziness, vomiting, personality changes, agitation, anxiety, confusion, oxygen cramps and fever. This problem should be avoidable in the context of modern intensive care measures by regularly checking the p O 2 in the context of a blood gas analysis. When diving with Nitrox , the maximum diving depth (MOD Maximum Operating Depth ) must be observed to prevent symptoms .

lung

If long-term ventilation with a high percentage of oxygen is necessary in the case of severe respiratory insufficiency with reduced oxygen uptake, damage to the alveolar membrane can lead to toxic pulmonary edema and chronic ventilation lung ( Lorrain-Smith effect ). In addition, bronchopulmonary dysplasia can occur.

eyes

In the immature eye of the premature baby, the uncontrolled formation of new vessels in the retina can lead to retinopathia prematurorum .

See also

literature

Individual evidence

  1. James T. Webb, RM Olson, RW Krutz, G. Dixon, PT Barnicott: Human tolerance to 100% oxygen at 9.5 psia during five daily simulated 8-hour EVA exposures . In: Aviation Space and Environmental Medicine . tape 60 , no. 5 , 1989, pp. 415-421 , PMID 2730484 .
  2. John M. Clark, Christian J. Lambertsen: Pulmonary oxygen tolerance in man and derivation of pulmonary oxygen tolerance curves . In: Environmental Biomedical Stress Data Center, Institute for Environmental Medicine, University of Pennsylvania Medical Center (Ed.): IFEM Report No. 1-70 . Philadelphia PA 1970 ( rubicon-foundation.org [accessed April 29, 2008]).