Prerequisites to commencing treatment

https://pubmed.ncbi.nlm.nih.gov/20363999/

A wound is defined as chronic when it does not heal according to the normal repair times and mechanisms. This particular condition may be principally due to local hypoxia. Carbon dioxide (CO(2)) therapy refers to the transcutaneous or subcutaneous administration of CO(2) for therapeutical effects on both microcirculation and tissue oxygenation. In this study, we report the clinical and instrumental results of the application of CO(2) in the therapy of chronic wounds. The study included 70 patients affected by chronic ulcers. The patients were selected by aetiology and wound extension and equally divided into two homogeneous groups. In group A, CO(2) therapy was used in addition to the routine methods of treatment for such lesions (surgical and/or chemical debridement, advanced dressings according to the features of each lesion). In group B, patients were treated using routine methods alone. Both groups underwent to instrumental (laser doppler flow, measurement of TcPO(2)), clinical and photographic evaluation. In the group that underwent subcutaneous treatment with CO(2) therapy, the results highlighted a significant increase in tissue oxygenation values, which was confirmed by greater progress of the lesions in terms of both healing and reduction of the injured area. Considering the safety, efficacy and reliability of this method, even if further studies are necessary, we believe that it is useful to include subcutaneous carbon dioxide therapy in the treatment of wounds involving hypoxia-related damage.

https://pubmed.ncbi.nlm.nih.gov/30066936/#:~:text=Hypoxic%20conditions%20promoted%20bone%20destruction,along%20with%20decreased%20osteoclast%20activity. 

Hypoxia plays a significant role in cancer progression, including metastatic bone tumors. We previously reported that transcutaneous carbon dioxide (CO2) application could decrease tumor progression through the improvement of intratumor hypoxia. Therefore, we hypothesized that decreased hypoxia using transcutaneous CO2 could suppress progressive bone destruction in cancer metastasis. In the present study, we examined the effects of transcutaneous CO2 application on metastatic bone destruction using an animal model. The human breast cancer cell line MDA-MB-231 was cultured in vitro under three different oxygen conditions, and the effect of altered oxygen conditions on the expression of osteoclast-differentiation and osteolytic factors was assessed. An in vivo bone metastatic model of human breast cancer was created by intramedullary implantation of MDA-MB-231 cells into the tibia of nude mice, and treatment with 100% CO2 or a control was performed twice weekly for two weeks. Bone volume of the treated tibia was evaluated by micro-computed tomography (µCT), and following treatment, histological evaluation was performed by hematoxylin and eosin staining and immunohistochemical staining for hypoxia-inducible factor (HIF)-1α, osteoclast-differentiation and osteolytic factors, and tartrate-resistant acid phosphatase (TRAP) staining for osteoclast activity. In vitro experiments revealed that the mRNA expression of RANKL, PTHrP and IL-8 was significantly increased under hypoxic conditions and was subsequently reduced by reoxygenation. In vivo results by µCT revealed that bone destruction was suppressed by transcutaneous CO2, and that the expression of osteoclast-differentiation and osteolytic factors, as well as HIF-1α, was decreased in CO2-treated tumor tissues. In addition, multinucleated TRAP-positive osteoclasts were significantly decreased in CO2-treated tumor tissues. Hypoxic conditions promoted bone destruction in breast cancer metastasis, and reversal of hypoxia by transcutaneous CO2 application significantly inhibited metastatic bone destruction along with decreased osteoclast activity. The findings in this study strongly indicated that transcutaneous CO2 application could be a novel therapeutic strategy for treating metastatic bone destruction. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916006/

Peripheral artery disease (PAD) is becoming a serious health problem of present times. It appears crucial to explore therapies that might help to restore blood flow or increase tissue oxygenation. The most effective methods of detecting early-stage changes in blood circulation in the extremities need to be identified. The aim of this study was to identify the effect of carbon dioxide (CO2) bathing on peripheral blood circulation measured by thermal imaging among patients with risk factors of PAD and ankle–brachial index (ABI) in the normal range or ABI indicating some or moderate arterial disease (ABI > 0.5). The correlation between surface temperature change and PAD-relevant characteristics was also examined. Forty-six patients who were over 65 years old who had a minimum of two additional PAD risk factors were recruited. A series of ten dry CO2 baths was performed. Thermal images were taken before and after the intervention. The CO2 therapy caused a significant change in the body surface temperature of many body areas. Numerous moderate correlations between temperature change and health-related characteristics were identified. Therefore, patients with PAD risk factors could benefit from CO2 therapy. Improvements in blood flow change the body surface temperature, and these changes could be successfully detected by thermal imaging. 

https://www.jstage.jst.go.jp/article/ptr/23/2/23_E10023/_article 

Objective: Joint contractures are a major complication following joint immobilization. However, no fully effective treatment has yet been found. Recently, carbon dioxide (CO2) therapy was developed and verified this therapeutic application in various disorders. We aimed to verify the efficacy of transcutaneous CO2 therapy for immobilization-induced joint contracture. Method: Twenty-two Wistar rats were randomly assigned to three groups: caged control, those untreated after joint immobilization, and those treated after joint immobilization. The rats were treated with CO2 for 20 min once a daily either during immobilization, (prevention) or during remobilization after immobilization (treatment). Knee extension motion was measured with a goniometer, and the muscular and articular factors responsible for contractures were calculated. We evaluated muscle fibrosis, fibrosis-related genes (collagen Type 1α1 and TGF-β1) in muscles, synovial intima's length, and fibrosis-related proteins (Type I collagen and TGF-β1) in the joint capsules. Results: CO2 therapy for prevention and treatment improved the knee extension motion. Muscular and articular factors decreased in rats of the treatment group. The muscular fibrosis of treated rats decreased in the treatment group. Although CO2 therapy did not repress the increased expression of collagen Type 1α1, the therapy decreased the expression of TGF-β1 in the treatment group. CO2 therapy for treatment improved the shortening of the synovial membrane after immobilization and decreased the immunolabeling of TGF-β1 in the joint capsules. Conclusions: CO2 therapy may prevent and treat contractures after joint immobilization, and appears to be more effective as a treatment strategy for the deterioration of contractures during remobilization.