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Partial Pressure Of Arterial Oxygen
Blood gas tension refers to the partial pressure of gases in blood. There are several significant purposes for measuring gas tension. The most common gas tensions measured are oxygen tension (PxO2), carbon dioxide tension (PxCO2) and carbon monoxide tension (PxCO). The subscript ''x'' in each symbol represents the source of the gas being measured: "''a''" meaning arterial, "''A''" being alveolar, "''v''" being venous, and "''c''" being capillary. Blood gas tests (such as arterial blood gas tests) measure these partial pressures. Oxygen tension ;Arterial blood oxygen tension (normal) PaO2 – Partial pressure of oxygen at sea level ( in the atmosphere, 21% of the standard atmospheric pressure of ) in arterial blood is between . ;Venous blood oxygen tension (normal) PvO2 – Oxygen tension in venous blood at sea level is between . Carbon dioxide tension Carbon dioxide is a by-product of food metabolism and in high amounts has toxic effects including: dyspnea, acidosis and altered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Oxygenation
Pulse oximetry is a Invasiveness of surgical procedures, noninvasive method for monitoring blood oxygen saturation (medicine), oxygen saturation. Oxygen saturation, Peripheral oxygen saturation (SpO2) readings are typically within 2% accuracy (within 4% accuracy in 95% of cases) of the more accurate (and invasive) reading of arterial oxygen saturation (SaO2) from arterial blood gas analysis. A standard pulse oximeter passes two wavelengths of light through tissue to a photodetector. Taking advantage of the Pulse, pulsate flow of arterial blood, it measures the change in absorption spectroscopy, absorbance over the course of a cardiac cycle, allowing it to determine the absorbance due to arterial blood alone, excluding unchanging absorbance due to venous blood, skin, bone, muscle, fat, and, in many cases, nail polish. The two wavelengths measure the quantities of bound (oxygenated) and unbound (non-oxygenated) hemoglobin, and from their ratio, the percentage of bound hemoglobin is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCO2
''p''CO2, pCO2, or P_\ce is the partial pressure of carbon dioxide (CO2), often used in reference to blood but also used in meteorology, climate science, oceanography, and limnology to describe the fractional pressure of CO2 as a function of its concentration in gas or dissolved phases. The units of ''p''CO2 are mmHg, atm, torr, Pa, or any other standard unit of atmospheric pressure. The ''p''CO2 of Earth's atmosphere has risen from approximately 280 ppm ( parts-per-million) to a mean 2019 value of 409.8 ppm as a result of anthropogenic release of carbon dioxide from fossil fuel burning. This is the highest atmospheric concentration to have existed on Earth for at least the last 800,000 years. Medicine In medicine, the partial pressure of carbon dioxide in arterial blood is called P_ or PaCO2. Measurement of P_ in the systemic circulation indicates the effectiveness of ventilation at the lungs' alveoli, given the diffusing capacity of the gas. It is a good indicator of r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematology
Hematology (American and British English spelling differences#ae and oe, spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the production of blood and its components, such as blood cells, hemoglobin, blood proteins, bone marrow, platelets, blood vessels, spleen, and the mechanism of coagulation. Such diseases might include hemophilia, sickle cell anemia, blood clots (thrombus), other bleeding disorders, and blood cancers such as leukemia, multiple myeloma, and lymphoma. The laboratory analysis of blood is frequently performed by a medical technologist or medical laboratory scientist. Specialization Physicians specialized in hematology are known as hematologists or haematologists. Their routine work mainly includes the care and treatment of patients with hematological diseases, although some may also work at the hema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraction Of Inspired Oxygen
Fraction of inspired oxygen (''FI''O2), correctly denoted with a capital ''I'', is the molar or volumetric fraction of oxygen in the inhaled gas. Medical patients experiencing difficulty breathing are provided with oxygen-enriched air, which means a higher-than-atmospheric ''FI''O2. Natural air includes 21% oxygen, which is equivalent to ''FI''O2 of 0.21. Oxygen-enriched air has a higher ''FI''O2 than 0.21; up to 1.00 which means 100% oxygen. ''FI''O2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity, but there are applications when up to 100% is routinely used. Often used in medicine, the ''FI''O2 is used to represent the percentage of oxygen participating in gas-exchange. If the barometric pressure changes, the ''FI''O2 may remain constant while the partial pressure of oxygen changes with the change in barometric pressure. Equations ;Abbreviated alveolar air equation :P_A \ce = \frac , , and are the partial pressures of oxygen in alv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fick's Laws Of Diffusion
Fick's laws of diffusion describe diffusion and were first posited by Adolf Fick in 1855 on the basis of largely experimental results. They can be used to solve for the diffusion coefficient, . Fick's first law can be used to derive his second law which in turn is identical to the diffusion equation. ''Fick's first law'': Movement of particles from high to low concentration (diffusive flux) is directly proportional to the particle's concentration gradient. ''Fick's second law'': Prediction of change in concentration gradient with time due to diffusion. A diffusion process that obeys Fick's laws is called normal or Fickian diffusion; otherwise, it is called anomalous diffusion or non-Fickian diffusion. History In 1855, physiologist Adolf Fick first reported* * his now well-known laws governing the transport of mass through diffusive means. Fick's work was inspired by the earlier experiments of Thomas Graham, which fell short of proposing the fundamental laws for which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Air Equation
The alveolar gas equation is the method for calculating partial pressure of alveolar oxygen (). The equation is used in assessing if the lungs are properly transferring oxygen into the blood. The alveolar air equation is not widely used in clinical medicine, probably because of the complicated appearance of its classic forms. The partial pressure of oxygen () in the pulmonary alveoli is required to calculate both the alveolar-arterial gradient of oxygen and the amount of right-to-left cardiac shunt, which are both clinically useful quantities. However, it is not practical to take a sample of gas from the alveoli in order to directly measure the partial pressure of oxygen. The alveolar gas equation allows the calculation of the alveolar partial pressure of oxygen from data that is practically measurable. It was first characterized in 1946. Assumptions The equation relies on the following assumptions: * Inspired gas contains no carbon dioxide () * Nitrogen (and any other gases e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anemia
Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin available for oxygen transport, or abnormalities in hemoglobin that impair its function. The name is derived . When anemia comes on slowly, the symptoms are often vague, such as Fatigue, tiredness, weakness, shortness of breath, headaches, and a Exercise intolerance, reduced ability to exercise. When anemia is acute, symptoms may include confusion, lightheadedness, feeling like one is going to pass out, Syncope (medicine), loss of consciousness, and polydipsia, increased thirst. Anemia must be significant before a person becomes noticeably Pallor, pale. Additional symptoms may occur depending on the underlying cause. Anemia can be temporary or long term and can range from mild to severe. Anemia can be caused by blood loss, decreased red blood cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbaric Chamber
A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of breathing gas for the occupants. There are two main functions for diving chambers: * as a simple form of submersible vessel to transport divers underwater and to provide a temporary base and retrieval system in the depths; * as a land, ship or offshore platform-based hyperbaric chamber or system, to artificially reproduce the hyperbaric conditions under the sea. Internal pressures above normal atmospheric pressure are provided for diving-related applications such as saturation diving and diver decompression, and non-diving medical applications such as hyperbaric medicine. Also known as a Pressure vessel for human occupancy, or PVHO. The engineering safety design code is ASME PVHO-1. Basic types of diving chambers There are two bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobin
Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers an animal's metabolism. A healthy human has 12to 20grams of hemoglobin in every 100mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and a globulin. In mammals, hemoglobin makes up about 96% of a red blood cell's dry matter, dry weight (excluding water), and around 35% of the total weight (including water). Hemoglobin has an oxygen-binding capacity of 1.34mL of O2 per gram, which increases the total blood oxygen capacity seventy-fold compared to dissolved oxygen in blood plasma alone. The mammalian hemoglobin molecule can bind and transport up to four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactic Acid
Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a hydroxyl group adjacent to the carboxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate (or the lactate anion). The name of the derived acyl group is lactoyl. In solution, it can ionize by a loss of a proton to produce the lactate ion . Compared to acetic acid, its p''K'' is 1 unit less, meaning lactic acid is ten times more acidic than acetic acid. This higher acidity is the consequence of the intramolecular hydrogen bonding between the α-hydroxyl and the carboxylate group. Lactic acid is chiral, consisting of two en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HCO3-
In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemical role in the physiological pH buffering system. The term "bicarbonate" was coined in 1814 by the English chemist William Hyde Wollaston. The name lives on as a trivial name. Chemical properties The bicarbonate ion (hydrogencarbonate ion) is an anion with the empirical formula and a molecular mass of 61.01 daltons; it consists of one central carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens. It is isoelectronic with nitric acid (). The bicarbonate ion carries a negative one formal charge and is an amphiprotic species which has both acidic and basic properties. It is both the conjugate base of carbonic acid (); and the conjugate acid of , the carbonate i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Saturation (medicine)
Oxygen saturation is the fraction of oxygen-saturated haemoglobin relative to total haemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 96–100 percent. If the level is below 90 percent, it is considered low and called hypoxemia. Arterial blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules () enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation. Definition In medicine, oxygen saturation, commonly referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
