Effect of hyperbaric oxygen on oxygen uptake and measurements in the blood and tissues in a normobaric environment.

OBJECTIVE To examine venous partial pressure of oxygen (PvO(2)), transcutaneous oxygen tension (tcPO(2)), and VO(2)MAX in a normobaric environment after a single hyperbaric oxygen (HBO(2)) treatment. METHODS This was a prospective study of conditions after the intervention compared with baseline. The participants were 10 moderately trained (VO(2)MAX = 57.6 ml/kg/min) men. Two HBO(2) treatments consisting of breathing 95% oxygen at 2.5 atmospheres absolute (ATA) for 90 minutes were administered on non-consecutive days. Baseline testing included measures of VO(2)MAX, tcPO(2), and anthropometry. At 6.0 (1.0) minutes after the first HBO(2) treatment, a VO(2)MAX test was performed. After the second HBO(2) treatment, leg and chest tcPO(2) and PvO(2) were monitored for 60 minutes. RESULTS VO(2)MAX, running time, and peak blood lactate were not altered after the HBO(2) treatment. Leg tcPO(2) was lower (p = 0.003) and chest tcPO(2) was unchanged after the HBO(2) treatment compared with baseline values. PvO(2) was significantly (p<0.001) lower in the first three minutes after treatment than subsequent values, but no other differences were found. CONCLUSIONS A single HBO(2) treatment at 2.5 ATA for 90 minutes does not raise PvO(2), tcPO(2), or VO(2)MAX in a normobaric, normoxic environment.