Hyperbaric oxygen therapy mediates increased nitric oxide production associated with wound healing: a preliminary study

Abstract

Objective: The objective of this preliminary study was to document general somatic and wound nitric oxide (NO) levels during and after hyperbaric oxygen therapy (HBOT).

Design: The study evaluated 6 chronic wound patients that responded favorably to HBOT treatment (20 treatments; 2.0 atmosphere absolute [ATA] x 90 minutes). Successful HBOT was associated with increased wound granulation tissue formation and significantly improved wound closure. Wound fluid and fasting plasma samples were obtained for measurement of nitrate and nitrite (NOx), the stable oxidation products of NO; plasma L-arginine (L-Arg); and asymmetric dimethylarginine (ADMA). NOx measurements were obtained before treatment (baseline), after 10 and 20 treatments, and at 1 and 4 weeks after therapy.

Results: Wound fluid NOx levels tended to increase during treatments, were significantly elevated at 1 and 4 weeks after therapy, and correlated with reductions in wound area. Plasma L-Arg and ADMA were unchanged during and after HBOT.

Conclusion: This preliminary study documents a significant increase in local wound NO levels (by NOx measurements) after successful HBOT and suggests that this mechanism may be an important factor in promoting enhanced wound healing and wound closure associated with this therapy.

Figure 1. Percentage of Wound area Change with Hbot

Illustration of changes in mean wound area (percentage) observed with HBOT study subjects 1 month before HBOT (PreTx), at baseline, after 10 treatments (10Tx), after 20 treatment (20Tx), and at 4 weeks after the completion of HBOT (HBOT4). **P < .05 for wound area reduction as compared to PreTx and HBOT values.

Figure 2. HBO-Wound Fluid NOx

Illustration of changes in mean wound fluid NOx (μM/L ± SE) values in study subjects at baseline, after 10 treatments (10Tx), after 20 treatments (20Tx), at 1 week after HBOT completion (HBOT1), and at 4 weeks after HBOT completion (HBOT4). **P < .05 as compared to baseline and 10Tx values.

Figure 3

Patient #3 (Table 1) at 6 weeks following failed attempts at recovery of local flaps used for reconstruction of ruptured left Achilles tendon. Patient #3 after wound bed preparation for hyperbaric oxygen therapy (HBOT) for treatment of failed flaps used with left Achilles tendon reconstruction. Patient #3 demonstrating complete closure of chronic wound of posterior left lower leg Achilles incision and local flaps 2 months following completion of HBOT.

Figure 3

Patient #3 (Table 1) at 6 weeks following failed attempts at recovery of local flaps used for reconstruction of ruptured left Achilles tendon. Patient #3 after wound bed preparation for hyperbaric oxygen therapy (HBOT) for treatment of failed flaps used with left Achilles tendon reconstruction. Patient #3 demonstrating complete closure of chronic wound of posterior left lower leg Achilles incision and local flaps 2 months following completion of HBOT.

Figure 3

Patient #3 (Table 1) at 6 weeks following failed attempts at recovery of local flaps used for reconstruction of ruptured left Achilles tendon. Patient #3 after wound bed preparation for hyperbaric oxygen therapy (HBOT) for treatment of failed flaps used with left Achilles tendon reconstruction. Patient #3 demonstrating complete closure of chronic wound of posterior left lower leg Achilles incision and local flaps 2 months following completion of HBOT.