Gas Toxicity While Diving

Various physiological gases (z. B. O2, N2, CO2) and non-physiological gases (z. B. carbon monoxide) can cause symptoms during the dive.

Various physiological gases (z. B. O2, N2, CO2) and non-physiological gases (z. B. carbon monoxide) can cause symptoms during the dive. Oxygen toxicity O2 toxicity occurs typically when the O2 partial pressure exceeds 1.4 atm, which is equivalent to a depth of about 57 m, when air is inhaled. Its symptoms include paresthesias, focal seizures, dizziness, nausea, vomiting and a constricted (tunnel) field. Approximately 10% of patients have generalized seizures or syncope, which usually leads to drowning. The risk is increased when divers breathe mixtures of O2 and N2 (Nitrox), which have a higher proportion of O2. Nitrogen narcosis When compressed air at depths inhaled by> 30 m, the increased N2 partial pressure exerts an anesthesia-like effect, according to the nitrous oxide from. A nitrogen narcosis ( “rapture of the deep”) causes symptoms and signs similar to those of alcohol poisoning (z. B. impaired intellectual and neuromuscular performance, behavioral and personality changes). Impaired judgment may result in drowning. Hallucinations and loss of consciousness can occur at depths of> 91 m. As the divers recover quickly during the emergence from the depths, the diagnosis is often made based on history. The treatment consists in an instant, but controlled ascent. A nitrogen narcosis can be avoided by helium is used to dilute O2 during deep diving because helium does not have the anesthetic properties of N2. However, the use of a pure helium / O2 mixture at very low dives elevated (> 180 m [> 600 ft]), the risk of high pressure neurological syndrome. Carbon dioxide poisoning CO2 poisoning may have one of the following causes: Inadequate breathing (hypoventilation) Passenger wetsuit overexertion malfunction of the regulator scuba diving oxygen tanks contamination from exhaled gases (such as may happen this at a CO2 scrubber loss in a rebreather air supply) A hypoventilation can the CO2 increase in the blood and cause breathing difficulties and sedation. In severe CO2 poisoning can cause nausea, vomiting, dizziness, headache, tachypnea and deep breathing, flushing, confusion, seizures and loss of consciousness. The suspicion of a slight CO2 poisoning is when the diver often has a headache in conjunction with diving or a low air consumption. CO2 poisoning usually disappears during ascending; therefore shows a BGA test after dipping significantly, no increased CO2 levels. The treatment consists in a gradual rise and the completion of the dip exercise or correction of the underlying cause. Carbon monoxide poisoning carbon monoxide can get into the air supply to a diver, if the Luftverdichteransaugventil is located or near an engine exhaust when lubricating oil is hot enough in a malfunctioning compressor to partially burn (flashing), thereby generating carbon monoxide. Symptoms include nausea, headache, weakness, clumsiness and changes in consciousness. In severe cases, seizures, syncope or coma may occur. Diagnosis is by the detection of an increased Carboxyhämoglobinspiegels (COHb) provided in the blood; the display of a pulse oximeter is not groundbreaking and usually normal because the pulse oximeter can not distinguish between oxyhemoglobin and COHb. The air supply to the diver can be tested for carbon monoxide. The treatment is carried out with 100% O2 with high flow, the best reduced by a non-rebreathing mask, the half-life of COHb of 4-8 h at room air at 40-80 min. In severe cases, a hyperbaric Sauerstoffherapie may be considered if it is immediately available. COHb levels drop in a hyperbaric pressure chamber rapidly (half-time 15-30 min), but the benefits of hyperbaric O2 therapy is controversial. Some studies show that the hyperbaric O2 therapy reduced neurological sequelae, but others do not support this finding. Neurological high pressure Syndrome A little understood syndrome neuromuscular and cerebral deviations can develop at ? 180 m depth, v. a. when the diver is quickly subjected to compression, while he inhales helium / O2 mixtures. Symptoms include nausea, vomiting, slight tremor, lack of coordination, dizziness, fatigue, somnolence, myoclonic jerking, stomach cramps and disturbances of intellectual and psychomotor performance. The diagnosis is made clinically. A prevention is usually in a slowing of the rate of compression.

Health Life Media Team

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