zwierzęta: Hypoxia (medicine)

Evidence: 100 • authority: 72

Hypoxia is a condition in which the body or a region of the body is deprived of an adequate oxygen supply at the tissue level. Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body. Although hypoxia is often a pathological condition, variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise. Hypoxia differs from hypoxemia and anoxemia, in that hypoxia refers to a state in which oxygen present in a tissue or the whole body is insufficient, whereas hypoxemia and anoxemia refer specifically to states that have low or no oxygen in the blood. Hypoxia in which the…

Evidence: 61 • authority: 72

Generalized hypoxia is a medical condition in which the tissues of the body are deprived of the necessary levels of oxygen due to an insufficient supply of oxygen, which may be due to the composition or pressure of the breathing gas, decreased lung ventilation, or respiratory disease, any of which may cause a lower than normal oxygen content in the arterial blood, and consequently a reduced supply of oxygen to all tissues perfused by the arterial blood. This usage is distinct from localized hypoxia, in which only an associated group of tissues, usually with a common blood supply, are affected, usually due to an insufficient or reduced blood supply to those tissues. Generalized hypoxia is al…

Evidence: 54 • authority: 88

Arterial and pulmonary arterial hemodynamics and oxygen delivery/extraction in normal humans exposed to hyperbaric air and oxygen. Divers and hyperbaric chamber attendants breathe hyperbaric air routinely. Hyperbaric oxygen (HBO 2 ) is used therapeutically frequently. Although much is understood about the hemodynamic physiology and gas exchange effects during hyperbaric air and HBO 2 exposure, arterial and pulmonary arterial (PA) catheter data, including blood gas values during hyperbaric air and HBO 2 exposure of normal humans, have not been reported. We exposed 10 healthy volunteers instrumented with arterial and PA catheters to air at 0.85, 3.0, 2.5, 2.0, 1.3 (decompression stop), 1.12 (…

Evidence: 48 • authority: 72

Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen (O2) at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lungs, and eyes. Historically, the central nervous system condition was called the Paul Bert effect, and the pulmonary condition the Lorrain Smith effect, after the researchers who pioneered the discoveries and descriptions in the late 19th century. Oxygen toxicity is a concern for underwater divers, those on high concentrations of supplemental oxygen, and those undergoing hyperbaric oxygen therapy. The result of breathing increased partial pressures o…

Evidence: 48 • authority: 92

Cerebral blood flow and metabolism under conditions of simulated avalanche burial in humans: The triple H syndrome.. Avalanche burial exposes individuals to a combination of hypothermia, hypercapnia and hypoxia. We investigated the impact of mild hypothermia on cerebrovascular function during room-air breathing and progressive hypercapnic hypoxia. In 14 participants (6 females) the radial artery and internal jugular vein were catheterized to measure blood gases, intravascular pressure, biomarkers of neurovascular damage (tau, neurofilament light (Nf-L) and glial fibrillary acidic protein (GFAP), whereas duplex ultrasound was used to quantify global cerebral blood flow (CBF), cerebral oxygen…

Evidence: 42 • authority: 80

<i>Normal Oxygen Saturation of Arterial Blood During Inhalation of Air and Oxygen</i>

Evidence: 42 • authority: 92

Eisenmenger Syndrome After Delayed Atrial Septal Defect Closure at High Altitude: A Case Report.. BACKGROUND Eisenmenger syndrome develops from untreated or late-repaired cardiac shunts, causing irreversible pulmonary-vascular remodeling and systemic symptoms. Although timely repair has nearly eradicated Eisenmenger syndrome in high-income regions, delayed diagnosis in middle-income countries, especially when combined with chronic high-altitude hypobaric hypoxia, such as at approximately 2800 m (9186 ft) in the Ecuadorian Andes, can accelerate pulmonary hypertension through hypoxic vasoconstriction and erythrocytosis. We report a case of Eisenmenger syndrome 2 decades after surgical atrial…

Evidence: 42 • authority: 72

An arterial blood gas (ABG) test, or arterial blood gas analysis (ABGA) measures the amounts of arterial gases, such as oxygen and carbon dioxide. An ABG test requires that a small volume of blood be drawn from the radial artery with a syringe and a thin needle, but sometimes the femoral artery in the groin or another site is used. The blood can also be drawn from an arterial catheter. An ABG test measures the blood gas tension values of the arterial partial pressure of oxygen (PaO2), and the arterial partial pressure of carbon dioxide (PaCO2), and the blood's pH. In addition, the arterial oxygen saturation (SaO2) can be determined. Such information is vital when caring for patients with cr…

Evidence: 42 • authority: 72

Breathing (respiring or ventilating) is the rhythmic process of inhaling air into the lungs providing oxygen, and exhaling the air removing carbon dioxide, in the gas exchange process. All aerobic organisms require oxygen for cellular respiration, which extracts energy from food and produces carbon dioxide as a waste product. External respiration (breathing) brings air to the alveoli where gases move by diffusion; the circulatory system then transports oxygen and carbon dioxide between the lungs and the tissues. In vertebrates with lungs, breathing consists of repeated cycles of inhalation and exhalation through a branched system of airways that conduct air from the nose or mouth to the alv…

Evidence: 36 • authority: 80

Interactions between calcium and reactive oxygen species in pulmonary arterial smooth muscle responses to hypoxia

Evidence: 36 • authority: 80

The effect of brief profound hypoxia upon the arterial and venous oxygen tensions in man

Evidence: — • authority: 80

Upper airway function of normal horses during exercise