Does Hyperbaric Oxygenation Improve Athletic Performance?

ABSTRACT

Šet, V, and Lenasi, H. Does hyperbaric oxygenation improve athletic performance? J Strength Cond Res 37(2): 482-493, 2023-Hyperbaric oxygen (HBO) has been suggested to affect oxygen availability and performance, and delay the onset of fatigue. Many mechanisms of HBO-induced alterations have been proposed, including modulation of various metabolic pathways, and the antioxidant defense mechanisms. As exercise per se affects similar aspects, it is tempting to speculate that simultaneous application of both, exercise and HBO might have synergistic effects. The aim of this review was to search through the currently available literature and evaluate the effect of acute exposure to HBO on exercise performance, potential effects of a combination of HBO and physical training, and to elucidate some possible mechanisms behind. We conducted searches in the PubMed and Scopus databases (search term: "hyperbaric" AND "oxygen" AND "exercise") and in relevant hyperbaric textbook and assessed potentially eligible full texts for details. Meta-analysis could not be performed because of a few available and rather heterogeneous studies. Twenty-seven studies were included in the final assessment (14 on exercise during HBO, 9 on exercise following HBO, 4 on applying HBO during recovery and rest between exercise bouts, and 3 on a combination of HBO and training). The results are contradictory, showing either positive or none ergogenic effects. There is some risk of bias and placebo effect. Discrepant findings of the available studies might partly be explained by different protocols applied, both regarding HBO and exercise intensity and regimen. There is a need for further research with well-designed trials to evaluate the effect of HBO on performance before recommending it to routine use in athletes.

Utility and safety of hyperbaric oxygen therapy as a rescue treatment in complicated cases of hypospadias: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to define the current evidence and systematically summarize the relevant data regarding the utility and safety of hyperbaric oxygen therapy (HBOT) as an adjunctive treatment in complicated re-operative cases of hypospadias.

METHOD

The authors systematically searched the PubMed, EMBASE, Web of Science, and Scopus databases on August 5, 2021. Patients were divided into two groups, i.e. HBOT and non-HBOT. The main outcomes were graft failure rate and the incidence of complications following urethroplasty. The proportion of patients developing adverse events due to HBOT was the secondary outcome. The pooled risk ratio and heterogeneity were calculated using the Mantel-Haenszel method and the I² statistics respectively. The quality assessment of the included studies was performed using the Downs and Black scale.

RESULT

Four studies constituting 176 patients (101 in the HBOT group) were included (Figure). Variations were observed among these studies in terms of the age of participants, the number and types of previous operations performed, and the protocol of administration of HBOT. The graft failure rate (RR 0.19; 95% CI 0.05-0.73, p = 0.02) and the incidence of complications (RR 0.40, 95% CI 0.20-0.77, p = 0.007) were significantly low in the HBOT versus the non-HBOT group. Apart from myringotomy insertion (n = 10; 9.9%) and claustrophobia (n = 1), no other adverse events were associated with HBOT. All studies had a moderate risk of bias. An almost perfect agreement (kappa = 0.956, p < 0.0001) was observed between the two investigators assessing the risk of bias.

CONCLUSION

The present systematic review and meta-analysis significantly favor the administration of HBOT versus no HBOT in terms of graft failure rate and incidence of complications following urethroplasty. The available data also highlights the safety of HBOT in complicated cases of hypospadias. However, well-designed randomized controlled trials need to be conducted for an optimal comparison between the two treatment groups.

The protective effects of 1,3-butanediol acetoacetate diester on decompression sickness in rats

Inert gas bubbles are widely accepted as the causative factor of decompression sickness (DCS), resulting in gas embolism and systemic inflammatory responses. The anticonvulsive ketone ester 1,3-butanediol acetoacetate diester (BD-AcAc₂) was reported to have the characteristics of increasing blood oxygen partial pressure (ppO₂) and anti-inflammation and was thought to have the potential to reduce bubble formation and alleviate the pathological process of DCS. This study aims to investigate the potential protection of BD-AcAc₂ against DCS in a rat model. A single dose of BD-AcAc₂ was administered orally to adult male rats (5 g/kg body wt), followed by pharmacokinetic analysis or simulated air dives. After decompression, signs of DCS were monitored, and blood was sampled for biochemical measurements. Blood ketosis peaked at 2 h and lasted for more than 4 h. The incidence of DCS was decreased and postponed significantly in rats treated with BD-AcAc₂ compared with those treated with saline (P < 0.05). Although BD-AcAc₂ failed to reduce bubble load (P > 0.05), it showed an obvious decreasing trend. BD-AcAc₂ significantly increased blood ppO₂ and ameliorated oxidative and inflammatory responses, represented by increased plasma malondialdehyde (MDA), IL-1, IL-6, and TNF-α and decreased glutathione thiol (P < 0.05) levels, whereas blood pH remained unchanged (P > 0.05). These results suggest that BD-AcAc₂ exerted beneficial effects on DCS rats mainly related to increasing ppO₂ and anti-inflammatory and antioxidant properties. Together with its capacity for delaying central nervous system (CNS) oxygen toxicity seizures, BD-AcAc₂ might be an ideal drug candidate for DCS prevention and treatment.NEW & NOTEWORTHY This is the first study exploring the effects of BD-AcAc₂ on DCS prevention, and it was proven to be an efficient and simple method. The role of BD-AcAc₂ in increasing ppO₂, anti-inflammatory and antioxidant properties was thought to be the critical mechanism in DCS prevention.

Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress

The present study was aimed at assessing endothelium-dependent vasorelaxation, at measuring superoxide production in the aorta and femoral artery, and at determining antioxidative enzyme expression and activity in aortas of male Sprague-Dawley rats (N = 135), randomized to an A-HBO₂ group exposed to a single hyperbaric oxygenation session (120′ of 100% O₂ at 2.0 bars), a 24H-HBO₂ group (single session, examined 24 h after exposure), a 4D-HBO₂ group (4 consecutive days of single sessions), and a CTRL group (untreated group). Vasorelaxation of aortic rings in response to acetylcholine (AChIR) and to reduced pO₂ (HIR) was tested in vitro in the absence/presence of NOS inhibitor L-NAME and superoxide scavenger TEMPOL. eNOS, iNOS, antioxidative enzyme, and NADPH oxidase mRNA expression was assessed by qPCR. Serum oxidative stress markers and enzyme activity were assessed by spectrometry, and superoxide production was determined by DHE fluorescence. Impaired AChIR and HIR in the A-HBO₂ group were restored by TEMPOL. L-NAME inhibited AChIR in all groups. Serum oxidative stress and superoxide production were increased in the A-HBO₂ group compared to all other groups. The mRNA expression of iNOS was decreased in the A-HBO₂ and 24H-HBO₂ groups while SOD1 and 3 and NADPH oxidase were increased in the 4D-HBO₂ group. The expression and activity of catalase and glutathione peroxidase were increased in the 4D-HBO₂ group as well. AChIR was NO dependent. Acute HBO₂ transiently impaired vasorelaxation due to increased oxidative stress. Vasorelaxation was restored and oxidative stress was normalized 24 h after the treatment.

Hyperbaric-Oxygen Therapy Improves Survival and Functional Outcome of Acute Severe Intracerebral Hemorrhage

BACKGROUND

Prognosis of spontaneous intracerebral hemorrhage (ICH) remains poor worldwide.

AIMS OF THE STUDY

To investigate the effect and optimal protocol for hyperbaric-oxygen therapy (HBOT), and reduce incidence of upper gastrointestinal bleeding (UGIB) in ICH.

METHODS

This prospective, randomized, controlled trial included 565 patients with acute severe ICH. Participants were randomly assigned to a sham-control group (Group A) and four intervention groups: Groups B and C with 2.0 atmospheres absolute (ATA) pressure and HBOT exposure for 60 or 90 sessions, respectively; and Groups D and E with 1.5 ATA for 60 or 90 sessions, respectively. All patients received emergency craniotomy with hematoma evacuation. Outcome measures were modified Barthel Index (MBI) and modified Rankin Scale (mRS) scores, mortality rates at follow-up six months. UGIB rates were assessed as potential side effect.

RESULTS

In four intervention groups, MBI and mRS scores were all significantly improved, and mortality rates were all significantly decreased compared with Group A (all p < 0.005). UGIB rates were 39.25, 60.00, 64.49, 36.79, and 34.26% in Groups A, B, C, D, and E, respectively. UGIB rates in Groups B and C were significantly increased compared with Groups A, D and E (all p < 0.005). None of UGIB were clinically significant.

CONCLUSIONS

HBOT significantly improves survival and functional outcomes of ICH. HBOT at 1.5 and 2.0 ATA had the same beneficial effect. A pressure of 1.5 ATA and 60 HBOT exposures represents an optimal protocol for HBOT. Further studies are needed to optimize the protocol per specific patient.

Optical Imaging of Tumor Response to Hyperbaric Oxygen Treatment and Irradiation in an Orthotopic Mouse Model of Head and Neck Squamous Cell Carcinoma

Purpose

Hyperbaric oxygen therapy (HBOT) is used in the treatment of radiation-induced tissue injury but its effect on (residual) tumor tissue is indistinct and therefore investigated in this study.

Procedures

Orthotopic FaDu tumors were established in mice, and the response of the (irradiated) tumors to HBOT was monitored by bioluminescence imaging. Near infrared fluorescence imaging using AngioSense750 and Hypoxisense680 was applied to detect tumor vascular permeability and hypoxia.

Results

HBOT treatment resulted in accelerated growth of non-irradiated tumors, but mouse survival was improved. Tumor vascular leakiness and hypoxia were enhanced after HBOT, whereas histological characteristics, epithelial-to-mesenchymal transition markers, and metastatic incidence were not influenced.

Conclusions

Squamous cell carcinoma responds to HBOT with respect to tumor growth, vascular permeability, and hypoxia, which may have implications for its use in cancer patients. The ability to longitudinally analyze tumor characteristics highlights the versatility and potential of optical imaging methods in oncological research.

Electronic supplementary material

The online version of this article (doi:10.1007/s11307-015-0834-8) contains supplementary material, which is available to authorized users.

Hyperbaric oxygen therapy and osteonecrosis

Osteonecrosis of the jaw may be caused by radiation, medication, or infection. Optimal therapy requires a multimodal approach that combines surgery with adjuvant treatments. This review focuses on the use of adjunctive hyperbaric oxygen therapy for this condition. In addition to evidence regarding the basic and clinical science behind hyperbaric oxygen therapy, controversies in the field and economic implications are discussed.

Hyperbaric oxygen for patients with above-knee amputations, persistent ischemia, and nonreconstructable vascular disease

We describe four patients with above-knee amputations whose stump wounds failed to heal. After numerous revascularization attempts, these patients were diagnosed with nonreconstructable pelvic and groin vascular disease and were facing hip disarticulation. With the addition of hyperbaric oxygen treatment to vigilant wound care and negative pressure therapy, these patients healed their amputation stumps and were fit with prostheses. At their most recent follow-up, all patients were ambulating and using their prostheses.

Hyperbaric oxygenation modulates vascular reactivity to angiotensin-(1-7) in diabetic rats: potential role of epoxyeicosatrienoic acids

Previously, a facilitating effect of hyperbaric oxygenation (HBO₂) on aortic ring responses to angiotensin-(1-7) in healthy rats was reported, with epoxyeicosatrienoic acids (EETs) possibly playing an important role. The aim of this study was to assess whether HBO₂ exerts similar effects in diabetic rats and to further explore the role of specific cytochrome P450 (CYP) enzymes in changes induced by HBO₂. Aortic relaxation to angiotensin-(1-7) was significantly higher in HBO₂ diabetic rats compared to control diabetic rats, while HBO₂ had no effect on angiotensin II contraction. N-methylsulphonyl-6-(2-propargyloxyphenyl/hexanamide inhibited the facilitation of angiotensin-(1-7) responses in HBO₂ rats, suggesting an important role of EETs in this modulation. mRNA expression of CYP2J3 and protein expression of CYP2C11 were significantly upregulated in HBO₂ diabetic rats, whereas CYP4A1, CYP4A2 and CYP4A3 mRNA and CYP2J3 protein expression was similar between groups. Mean arterial pressure, ferric reducing ability of plasma and Thiobarbituric Acid Reactive Substances levels and serum angiotensin-(1-7) concentrations were not significantly changed.