Mechanisms of action of hyperbaric oxygen therapy
Therapeutic mechanisms of action for hyperbaric oxygen (HBO2) therapy are based on elevation of both the partial pressure of inspired O2 and of the hydrostatic pressure. This last mechanism contributes to a compression of all gas-filled spaces in the body (Boyle's Law) and is relevant to treat conditions where gas bubbles are present in the body and cause the disease (e.g., intravascular embolism; decompression sickness with intravascular or intra-tissue bubbles). However, the majority of patients treated with HBO2 do not suffer from bubble-induced injuries, but derive clinical improvements from the elevated O2 partial pressures. High O2 partial pressures in various tissues increase the production of reactive O2 species (ROS) and also of reactive nitrogen species (RNS) because of hyperoxia. Most controlled studies have verified that the clinical efficacy from HBO2 derives from modulation of intracellular transduction cascades, leading to synthesis of growth factors and promoting wound healing and ameliorating post-ischemic and post-inflammatory injuries.
Available from: Rinaldo Florencio-Silva
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ABSTRACT: To evaluate the morphology, necrotic area and collagen content in skin flaps of rats subjected to hyperbaric oxygenation (HBO).
Forty adult rats were divided into four groups: GEC - epilated; GE/HBO - epilated subjected to HBO; GER - epilated submitted to skin flap (2 cm in width /8 cm length in the dorsal area) and GER/HBO - epilated, subjected to skin flap and HBO. HBO (2.4 ATA) was performed for two hours during seven consecutive days. In the eighth day, the rats were anesthetized and the skin flaps were removed and separated into three portions, relative to pedicle fixation. The material fixed in 10% formalin was processed for paraffin embedding; sections were stained by H.E and subjected to picrosirius-red method. The slides examined under light microscopy for evaluation of the collagen content in polarized light microscope and ImageLab(r) software (Bio-Rad).
The data showed larger area of necrosis and lower levels of collagen in the three regions of the GER group, whereas in the GER/HBO group the collagen content was similar to the GEC and GE/HBO groups.
Hyperbaric oxygenation reduced the area of necrosis and preserved the morphology and collagen content in skin flaps of rats.
Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 04/2015; 30(4):235-41. DOI:10.1590/S0102-865020150040000001 · 0.66 Impact Factor
Available from: Mansher Singh
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ABSTRACT: The skin wound microenvironment can be divided into two main components that influence healing: the external wound microenvironment, which is outside the wound surface; and the internal wound microenvironment, underneath the surface, to which the cells within the wound are exposed. Treatment methods that directly alter the features of the external wound microenvironment indirectly affect the internal wound microenvironment due to the exchange between the two compartments. In this review, we focus on the effects of temperature, pressure (positive and negative), hydration, gases (oxygen and carbon dioxide), pH, and anti-microbial treatment on the wound. These factors are well described in the literature and can be modified with treatment methods available in the clinic. Understanding the roles of these factors in wound pathophysiology is of central importance in wound treatment. This article is protected by copyright. All rights reserved.
© 2015 by the Wound Healing Society.
Wound Repair and Regeneration 04/2015; 23(4). DOI:10.1111/wrr.12303 · 2.75 Impact Factor
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