title: Brief screening test of ventilatory sensitivity to CO₂ cannot replace the mandatory test for susceptibility to CNS oxygen toxicity.
abstract: Central nervous system oxygen toxicity is a major risk in closed-circuit diving, and the risk increases with elevation of the inspired carbon dioxide (CO2). Mandatory tests for CO2 retention and detection are common practice at the Israel Naval Medical Institute, for the instruction and selection of combat divers at an advanced stage in their training. Read test is a simpler test of the ventilatory response to CO2. Positive correlation between parameters from Read and mandatory tests, enable conducting the test at an earlier stage in diving candidates. In the mandatory test, divers (n = 45) breathing various levels of CO2 in oxygen, and tested for the detection and retention of CO2 reported their sensations. In the Read test, we recorded end-tidal CO2 and ventilation in subjects as they rebreathed from rubber bag. The slope of ventilation was calculated as a function of end-tidal CO2. There was low correlation between any of the parameters from our test and the Read test. There was low insignificant correlation between any parameter from the Read test and detection or retention of CO2. We cannot use the Read test as a test for CO2 retention or detection at an earlier stage in diving candidates.
authors.affiliation: Israel Naval Medical Institute (INMI), Israel Defense Forces Medical Corps, Box 22, Rambam Health Care Campus, P.O. Box 9602, 3109601 Haifa, Israel.
authors.forename: Ran
authors.initials: R
authors.lastname: Arieli
authors.affiliation: Israel Naval Medical Institute (INMI), Israel Defense Forces Medical Corps, Box 22, Rambam Health Care Campus, P.O. Box 9602, 3109601 Haifa, Israel.
authors.forename: Mirit
authors.initials: M
authors.lastname: Eynan
authors.affiliation: Israel Naval Medical Institute (INMI), Israel Defense Forces Medical Corps, Box 22, Rambam Health Care Campus, P.O. Box 9602, 3109601 Haifa, Israel.
authors.forename: Dror
authors.initials: D
authors.lastname: Ofir
authors.affiliation: Israel Naval Medical Institute (INMI), Israel Defense Forces Medical Corps, Box 22, Rambam Health Care Campus, P.O. Box 9602, 3109601 Haifa, Israel.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Arieli
mesh_terms: D001944:Breath Tests; D002245:Carbon Dioxide / Q000032:analysis* / Q000378:metabolism; D002493:Central Nervous System Diseases / Q000209:etiology*; D004198:Disease Susceptibility / Q000175:diagnosis*; D004242:Diving / Q000502:physiology*; D004244:Dizziness / Q000209:etiology; D006261:Headache / Q000209:etiology; D006801:Humans; D008297:Male; D010100:Oxygen / Q000506:poisoning*; D012123:Pulmonary Ventilation / Q000502:physiology; D012677:Sensation / Q000502:physiology
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen