The pulmonary oxygen toxicity index.

Pulmonary oxygen toxicity (POT) is a major risk in diving while breathing hyperoxic gas and is also considered in clinical hyperbaric oxygen treatment. The POTindex calculated by the power equation K = t2 × PO24.57 with the recovery form Ktr = Ke × e - [- 0.42 + 0.384 × (PO2)ex] × tr which are based on chemical and physiological principles, have a better prediction power than other suggested approaches. Reduction of vital capacity as well as incidence of POT are well predicted by the POTindex. Both the cumulative pulmonary toxic effect and concomitant recovery were suggested to operate at the lower toxic range of PO2 used in saturation diving K = t2 × PO24.57 × e-0.0135 × t, and further experimental support is supplied. The recovery time constant for the full range of PO2 is presented. POTindex is suggested to replace the old method of UPTD for safe diving. Many diving clubs and diving institutes already adopted the POTindex.