Data from: A single session of hyperbaric oxygen therapy demonstrates acute and long-lasting neuroplasticity effects in humans: a replicated, randomized controlled clinical trial

Purpose: Animal studies have demonstrated anti-inflammatory, and
anti-nociceptive properties of hyperbaric oxygen therapy (HBOT). However,
physiological data are scarce in humans. In a recent experimental study,
the authors used the burn injury (BI) model observing a decrease in
secondary hyperalgesia area (SHA) in the HBOT-group compared to a
control-group.Surprisingly, a long-lasting neuroplasticity effect
mitigating the BI-induced SHA-response was seen in the HBOT-preconditioned
group. The objective of the present study, therefore, was to confirm our
previous findings using an examiner-blinded, block-randomized, controlled,
crossover study design. Patients and methods: Nineteen healthy subjects
attended two BI-sessions with an inter-session interval of ≥28 days. The
BIs were induced on the lower legs by a contact thermode (12.5 cm2, 47C°,
420 s). The subjects were block-randomized to receive HBOT (2.4 ATA, 100%
O2, 90 min) or ambient conditions ([AC]; 1 ATA, 21% O2), dividing cohorts
equally into two sequence allocations: HBOT-AC or AC-HBOT. All sensory
assessments performed during baseline, BI, and post-intervention phases
were at homologous time points irrespective of sequence allocation. The
primary outcome was SHA, comparing interventions and sequence allocations.
Data are mean (95% CI). Results: During HBOT-sessions a mitigating effect
on SHAs was demonstrated compared to AC-sessions, ie, 18.8 (10.5–27.0) cm2
vs 32.0 (20.1–43.9) cm2 (P=0.021), respectively. In subjects allocated to
the sequence AC-HBOT a significantly larger mean difference in SHA in the
AC-session vs the HBOT-session was seen 25.0 (5.4–44.7) cm2 (P=0.019). In
subjects allocated to the reverse sequence, HBOT-AC, no difference in SHA
between sessions was observed (P=0.55), confirming a preconditioning,
long-lasting (≥28 days) effect of HBOT. Conclusion: Our data demonstrate
that a single HBOT-session compared to control is associated with both
acute and long-lasting mitigating effects on BI-induced SHA, confirming
central anti-inflammatory, neuroplasticity effects of hyperbaric oxygen
therapy.