198 KB46 KB199420252002Jošt, AntonPakiž, Majaštevilka:1letnik:41str. 27-40ISSN:0025-8121COBISSID:15277785URN:URN:NBN:SI:doc-K6O8VB3LslMedicinski razglediMedicinski razglediAcid-base equilibriumAcid-base imbalanceacidobazno ravnotežjeAcido-bazno ravnotežjeAcidobazno ravnotežje, motnjeAcidosisAcidosis, respiratoryAcidozaAcidoza dihalnaAlkalosisAlkalosis, respiratoryAlkalozaAlkaloza dihalnabiokemijaBuffersDiagnosisdiagnostikafiziologijamotnjepresnovaPufriTherapyzdravljenjeKislinsko-bazno ravnovesje| Acid-base balance|Acids are donors, while bases are acceptors of protons in solutions. Many various acids and bases are incorporated into organisms by everyday alimentation and cell metabolism, while the output routes are the respiratory system, kidneys and gastrointestinal system. The concentration of free protonsin the blood (expressed as pH value) is strictly regulated, as it has agreat impact on cell metabolism. There are many ways in which organisms defend themselves against harmful pH changes. The first line of defense is buffering, which takes place in both extra- and intracellular fluids; the second is regulation of elimination of acids and bases via the respiratory system (volatile acids) and kidneys (nonvolatile acids - sodium hydrogen carbonate). Many parameters can be determined from blood and urine samples, which can help diagnose and monitor patient acid-base disorders. Important measurements of urine include pH, urinary titrable acid and net acid excretionfor blood pH, hydrogen carbonate concentration and partial pressure of carbon dioxide. For further analysis of metabolic acidosis, base ex*ess, anion and osmolal gaps need to be determined. Acid-base disorders are divided into metabolic disorders with primary change in blood hydrogen carbonate concentration, and respiratory disorders with primary change in partial pressure of carbon dioxide. Acidosis causes a decrease in blood pH, while alkalosis causes an increase. The management of these disorders mainly consists of treatment of the underlying disease. In severe cases, it is also necessary to correct the pH status by adding acids or bases to the patient's bloodKisline so dajalci, baze pa prejemniki protonov Tako kisline kot baze vnašamo v organizem s hrano in jih pridobivamo pri celični presnovi, izgubljamo pa jihpreko dihalnega sistema, ledvic in prebavnega trakta. Koncentracija protonov v krvi (izražamo jo s pH) je natančno uravnavana, saj pomembno vplivana potek celične presnove. Organizem se proti spremembi pH krvi brani z več mehanizmi. Prva obramba je pufranje, ki poteka v zunaj- in znotrajceličnihtekočinah. Drugi odgovor je izločanje ali zadrževanje kislin oziroma baz preko dihalnega sistema (hlapne kisline) in ledvic (nehlapne kisline, hidrogenkarbonat). V diagnostiki in spremljanju motenj kislinsko-baznega ravnovesja določamo več parametrov v seču in krvi. V seču merimo pH, titrabilno kislost seča in neto izločanje kislin preko ledvic. V krvi določimo njeno pH, koncentracijo hidrogenkarbonata, dehu tlak ogljikovegadioksida, za iskanje vzroka presnovnih motenj pa ugotavljamo še bazni prebitek, anionsko in osmolalno vrzel. Motnje kislinsko-baznega ravnovesja delimo na presnovne, kjer se prvotno spremeni koncentracija hidrogenkarbonata v krvi, ter na dihalne, kjer se v prvi vrsti spremeni delni tlak ogljikovega dioksida. Acidoza je stanje, ki pripelje do padca krvnega pH,alkaloza je stanje, ki je vzrok porastu krvnega pH. Motnje odpravljamo tako, da zdravimo bolezen, zaradi katere se je pH krvi spremenil. V primeru hudega odstopanja pH pa v kri dodajamo kisline oziroma bazeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaDruštvo Medicinski razgledi