Influence of hyperbaric oxygen therapy on thrombus formation ability in humans.

Background: Hyperbaric oxygen (HBO2) therapy was introduced nearly 300 years ago. However, its effect on thrombus formation is unclear. This may be because platelet and coagulation functions are unstable, yielding variable results; hence, accurate measurement is difficult. Our study aimed to analyze changes in thrombus formation before and after HBO2 therapy by using a total thrombus formation analysis system (TTAS). Methods: Six patients were prescribed HBO2 therapy for skin and soft tissue ulcers, and necrotic fasciitis. Blood samples were collected immediately before and after treatment. Then samples were put into a reservoir that connected to AR-chip to assess changes in the thrombus formation ability of both platelets and coagulation factors. We examined the differences in the thrombus formation ability using T-TAS. Time until the onset of white thrombus formation (T10) and complete occlusion of the capillary (T80) were analyzed by a two-way repeated measure analysis of variance (ANOVA). Results: The duration to pressure increase of samples after HBO2 therapy was longer than the duration before HBO2 therapy (p<0.05). This suggests decreased clot adhesiveness to the inner surface of the simulated blood vessel and reduced clot formation ability. Conclusions: The results for T10 and T80 suggest that HBO2 therapy reduced thrombus formation ability in the enrolled patients. We believe that T-TAS is a promising method to predict the efficacy of HBO2 therapy.

Integrin-mediated adhesive properties of neutrophils are reduced by hyperbaric oxygen therapy in patients with chronic non-healing wound.

In recent years, several studies suggested that the ability of hyperbaric oxygen therapy (HBOT) to promote healing in patients with diabetic ulcers and chronic wounds is due to the reduction of inflammatory cytokines and to a significant decrease in neutrophils recruitment to the damaged area. α4 and ß2 integrins are receptors mediating the neutrophil adhesion to the endothelium and the comprehension of the effects of hyperbaric oxygenation on their expression and functions in neutrophils could be of great importance for the design of novel therapeutic protocols focused on anti-inflammatory agents. In this study, the α4 and ß2 integrins' expression and functions have been evaluated in human primary neutrophils obtained from patients with chronic non-healing wounds and undergoing a prolonged HBOT (150 kPa per 90 minutes). The effect of a peptidomimetic α4ß1 integrin antagonist has been also analyzed under these conditions. A statistically significant decrease (68%) in ß2 integrin expression on neutrophils was observed during the treatment with HBO and maintained one month after the last treatment, while α4 integrin levels remained unchanged. However, cell adhesion function of both neutrophilic integrins α4ß1 and ß2 was significantly reduced 70 and 67%, respectively), but α4ß1 integrin was still sensitive to antagonist inhibition in the presence of fibronectin, suggesting that a combined therapy between HBOT and integrin antagonists could have greater antinflammatory efficacy.

Vitamin D serum levels and the risk of digital ulcers in systemic sclerosis: A longitudinal study.

AIM: Low levels of vitamin D (25OHD) have been found to associated with digital ulcers (DUs) in systemic sclerosis (SSc), although only cross-sectional studies have been performed. We aimed to investigate if variations in vitamin D serum levels over time affect DU in SSc. METHODS: This is a retrospective study on 65 patients. 25OHD was measured in 2011 and 2016 and its variations correlated with DU. RESULTS: The mean age of our cohort was 58 (SD 12) years with a mean disease duration of 9.5 (5.3) years. Most of our patients had a limited SSc (69.2%). At baseline 50.8% and 41.5% after 5 years had 25OHD <30 ng/mL. Patients receiving supplementation (8750 IU/wk) at baseline numbered 39 (60.0%) and 45 (69.2%) at the end of follow up. Nevertheless, 31 (47.7%) had a decrease of 25OHD in 5 years. In univariate analysis, patients with incident DU had a decrease in 25OHD as compared to patients with no incident DU (-17.4 [37.0] vs 13.0 [89.5], P = 0.018). No differences in 25OHD variations were found for other disease characteristics. In multivariate analysis correcting for previous DU and modified Rodnan Skin Score at baseline, patients with a decrease in 25OHD had an increased risk of developing DU (odds ratio 16.6; 95% CI 1.7-164.5, P = 0.017). CONCLUSIONS: A decrease in 25OHD is associated with the risk of developing DUs. In addition, vitamin D supplementation with the doses currently recommended may be insufficient in SSc. Further studies in wider cohorts are needed to confirm these results.

Calciphylaxis: a case report.

Calciphylaxis or calcific uremic arteriolopathy is characterized by the involvement of the tunica elastica of the reticular or deep subcutaneous dermis, with extravascular and vascular thrombosis calcifications that lead to tissular ischemia. The torso muscles, the lumbar region, and lower limbs are more frequently affected. The pathogenesis is unknown. Calciphylaxis is associated to hyperparathyroidism, chronic renal failure, and diabetes mellitus. The best therapy to date is prevention: early treatment of renal failure, performing a partial parathyroidectomy where necessary, surgical debridement of the necrotic tissue, as well as avoiding the trigger factors such as systemic corticosteroids.

TCOMs as a screening tool for hyperbaric oxygen therapy.

Transcutaneous oximetry (TcPO2), often referred to as TCOM, is a noninvasive measurement of oxygen tension in the tissue via a heated electrode. TCOMs can be used prior to beginning hyperbaric oxygen (HBO) treatment to determine if the patient has adequate blood flow to the wounded area to benefit from HBO. A case study of how it can be used in a problematic wound is presented.