Gastric Tonometry
   HOME





Gastric Tonometry
Gastric tonometry describes the measurement of the carbon dioxide level inside the stomach in order to assess the degree of blood flow to the stomach and bowel. Method Gastric tonometry has been introduced as a novel method of monitoring tissue perfusion in critically ill patients. Tonometry is based on the principle that at equilibrium the partial pressure of a diffusible gas such as CO2 is the same in both the wall and lumen of a viscus. The technique therefore can estimate gut mucosal PCO2 by measuring gut luminal PCO2 at equilibrium. A saline-filled balloon made of CO2 permeable silicone attached to a sampling tube is introduced into the gastric lumen as a nasogastric tube would be. After an equilibration period the fluid is sampled to measure PCO2. Because the mucosal and systemic bicarbonate concentrations are equal, a modified Henderson-Hasselbalch equation may be used to calculate the intramucosal pH: pHi = 6.1 + log CO3−/0.03 x PCO2 Thus, only gastric luminal PCO2 is ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Carbon Dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared, infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. It is a trace gas Carbon dioxide in Earth's atmosphere, in Earth's atmosphere at 421 parts per million (ppm), or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. Burning fossil fuels is the main cause of these increased concentrations, which are the primary cause of climate change.IPCC (2022Summary for pol ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Stomach
The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical terms related to the stomach. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase, gastric phase of digestion, following the cephalic phase in which the sight and smell of food and the act of chewing are stimuli. In the stomach a chemical breakdown of food takes place by means of secreted digestive enzymes and gastric acid. It also plays a role in regulating gut microbiota, influencing digestion and overall health. The stomach is located between the esophagus and the small intestine. The pyloric sphincter controls the passage of partially digested food (chyme) from the stomach into the duodenum, the first and shortest part of the small intestine, where p ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Tonometry
Tonometry is the procedure that eye care professionals perform to determine the intraocular pressure (IOP), the fluid pressure inside the eye. It is an important test in the evaluation of patients at risk from glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg), with the normal eye pressure range between . Methods Applanation tonometry In applanation tonometry the intraocular pressure (IOP) is inferred from the force required to flatten (applanate) a constant area of the cornea, for the Imbert-Fick law. The Maklakoff tonometer was an early example of this method, while the Goldmann tonometer is the most widely used version in current practice. Because the probe makes contact with the cornea, a topical anesthetic, such as proxymetacaine, is introduced on to the surface of the eye in the form of an eye drop. Goldmann tonometry Goldmann applanation tonometry (GAT) is considered to be the gold standard IOP test and is the most widely ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]