Bench-to-bedside Review: Oxygen As A Drug

Oxygen is one of the most commonly used therapeutic agents. Injudicious use of oxygen at excessive partial pressures (hyperoxia) for painless SPO2 testing unproven indications, its recognized toxic potential, and the acknowledged roles of reactive oxygen species in tissue injury led to skepticism concerning its use. A large body of data signifies that hyperoxia exerts an extensive profile of physiologic and pharmacologic effects that enhance tissue oxygenation, exert anti-inflammatory and antibacterial results, and increase tissue repair mechanisms. These data set the rationale for using hyperoxia in a list of clinical circumstances characterized by tissue hypoxia, infection, and consequential impaired tissue restore. Data on regional hemodynamic results of hyperoxia and monitor oxygen saturation latest compelling evidence on its anti-inflammatory actions incited a surge of interest within the potential therapeutic results of hyperoxia in myocardial revascularization and protection, in traumatic and nontraumatic ischemicanoxic mind insults, and in prevention of surgical site infections and in alleviation of septic and nonseptic native and systemic inflammatory responses.



Although the margin of safety between effective and probably toxic doses of oxygen is comparatively narrow, the ability to carefully management its dose, meticulous adherence to currently accepted therapeutic protocols, and individually tailor-made therapy regimens make it a cost-effective safe drug. Oxygen is among the most widely used therapeutic agents. It's a drug within the true sense of the phrase, with particular biochemical and physiologic actions, a distinct range of effective doses, and nicely-defined antagonistic effects at excessive doses. Oxygen is widely obtainable and commonly prescribed by medical staff in a broad range of circumstances to relieve or forestall tissue hypoxia. Although oxygen therapy stays a cornerstone of trendy medical follow and although many elements of its physiologic actions have already been elucidated, evidence-based information on its effects in many doubtlessly relevant clinical situations are lagging behind. The price of a single use of oxygen is low. Yet in many hospitals, the annual expenditure on oxygen therapy exceeds these of most different high-profile therapeutic agents.



The simple availability of oxygen lies beneath a scarcity of commercial interest in it and the paucity of funding of massive-scale clinical studies on oxygen as a drug. Furthermore, the commonly accepted paradigm that links hyperoxia to enhanced oxidative stress and the relatively slim margin of safety between its efficient and toxic doses are further limitations accounting for the disproportionately small variety of high-quality studies on the clinical use of oxygen at increased-than-normal partial pressures (hyperoxia). Yet it is easy to meticulously control the dose of oxygen (the mix of its partial stress and duration of exposure), in distinction to many other drugs, and due to this fact clinically important manifestations of oxygen toxicity are unusual. The present overview summarizes physiologic and pathophysiologic principles on which oxygen therapy relies in clinical situations characterized by impaired tissue oxygenation with out arterial hypoxemia. Normobaric hyperoxia (normobaric oxygen, NBO) is utilized via a large variety of masks that enable supply of impressed oxygen of 24% to 90%. Higher concentrations may be delivered by way of masks with reservoirs, tightly fitting steady positive airway pressure-sort masks, or during mechanical ventilation.



There are two methods of administering oxygen at pressures higher than 0.1 MPa (1 atmosphere absolute, 1 ATA) (hyperbaric oxygen, HBO). In the first, a small hyperbaric chamber, normally designed for a single occupant, is used. The chamber is stuffed with 100% oxygen, which is compressed to the pressure required for treatment. With the second method, the treatment is given in a big multiplace hyperbaric chamber. A multiplace walk-in hyperbaric chamber. The treatment strain is attained by compressing the ambient air within the chamber. Patients are uncovered to oxygen or BloodVitals SPO2 other gasoline mixtures at the same strain through masks or hoods. Many hyperbaric amenities are equipped for offering a full-scale critical care surroundings, including mechanical ventilation and state-of-the-art monitoring. Delivery of oxygen to tissues is determined by adequate ventilation, fuel change, and painless SPO2 testing circulatory distribution. When air is breathed at normal atmospheric stress, many of the oxygen is certain to hemoglobin whereas only little or no is transported dissolved in the plasma.



On publicity to hyperoxia, hemoglobin is totally saturated with oxygen. This accounts for only a small increase in arterial blood oxygen content. In addition, the amount of physically dissolved oxygen within the blood additionally increases in direct proportion to the ambient oxygen partial pressure. As a result of low solubility of oxygen in blood, the quantity of dissolved oxygen in arterial blood attainable throughout normobaric exposures to 100% oxygen (about 2 vol%) can present only one third of resting tissue oxygen requirements. Inhalation of 100% oxygen yields a 5- to 7-fold enhance in arterial blood oxygen tension at normal atmospheric pressure and should attain values near 2,000 mm Hg during hyperbaric publicity to oxygen at 0.Three MPa (3 ATA). The marked enhance in oxygen tension gradient from the blood to metabolizing cells is a key mechanism by which hyperoxygenation of arterial blood can improve efficient cellular oxygenation even at low charges of tissue blood stream. Regrettably, the particular value of oxygen therapy was not assessed in this research.