Acid base balance
PreliminaryThe degree of acidity is an important chemical properties of the blood and other body fluids. Unit acidity is pH.
Classification pH• pH of 7.0 is neutral• pH above 7.0 is alkaline (alkali)• pH below 7.0 is acidicA strong acid has a very low pH (about 1.0), while a strong base has a very high pH (above 14.0). Blood has a pH of between 7.35 to 7.45. Acid-base balance of the blood is carefully controlled, because of the very small changes in pH can be serious effects on several organs.Acid base balance settingscontinueThe body uses three mechanisms to control the acid-base balance of blood1. Excess acid is removed by the kidneys, mostly in the form of ammonia. The kidneys have the ability to change the amount of acid or base were removed, which usually lasts for several days.2. The body uses buffer pH (buffer) in the blood as a protection against the changes that occur suddenly in blood pH. A pH buffer works chemically to minimize the change in pH of a solution. The most important pH buffer in the blood is bicarbonate. Bicarbonate (a base component) are in equilibrium with the carbon dioxide (a component of acid). If more acid enters the bloodstream, it will produce more bicarbonate and less carbon dioxide. If more alkaline into the bloodstream, it will produce more carbon dioxide and less bicarbonate.3. Disposal of carbon dioxide. Carbon dioxide is an important by-product of oxygen metabolism and continuously generated by the cell. The blood carries carbon dioxide to the lungs. In the lungs of carbon dioxide is released (exhaled). Respiratory center in the brain that regulate the amount of carbon dioxide exhaled by controlling the rate and depth of breathing.If breathing increased, decreased blood carbon dioxide levels and blood becomes more alkaline. If respiration decreases, blood carbon dioxide levels increase and the blood becomes more acidic. By adjusting the speed and depth of breathing, the respiratory center and lungs able to regulate blood pH minute by minute.PH values can be seen from the arterial blood with normal range 7.35 to 7.45. Prices are normal results of laboratory blood gas analysis is as follows:pH from 7.35 to 7.4580-100 mmHg pO2pCO2 35-45 mmHg[HCO3-] 21-25 mmol / LBase excess -2 s / d +2Abnormalities in one or more of the mechanisms controlling the pH, can cause one of the two major abnormalities in acid-base balance, ie acidosis or alkalosis.Acid base balance disorders and HandlingFactors that influence the acid-base balance are:1. Hydrogen ion concentration [H +]2. The concentration of bicarbonate ion [HCO3-]3. pCO2The following comparison of the role of each factor in the diagnosis of acid-base disturbances:- When the concentration of H + increases, the pH drops called acidosis- When the concentration of H + down, then the pH rises alkalosis- When HCO3-significantly changed in condition, called a state of metabolic- When pCO2 changed significantly in such conditions, a condition called respiratoryFrom concept, found four conditions, namely:1. Metabolic acidosis2. Respiratory acidosis3. Metabolic alkalosis4. Respiratory alkalosisAcidosis is a condition where the blood has too much acid (or are very low base) and often causes decreased blood pH. Alkalosis is a condition where the blood has too much base (or too little acid) and sometimes cause increased blood pH.Acidosis and alkalosis is not a disease but rather a result of a number of diseases. The occurrence of acidosis and alkalosis is an important clue of the existence of serious metabolic problems. Acidosis and alkalosis are grouped into metabolic or respiratory, depending on the primary cause.Metabolic acidosis and metabolic alkalosis is caused by an imbalance in the creation and disposal of acid or base by the kidneys. Respiratory acidosis or respiratory alkalosis mainly due to lung disease or breathing disorders.Metabolic Acidosis ---------------------------------DefinitionMetabolic Acidosis is excessive blood acidity, which is characterized by low levels of bicarbonate in the blood. If the increase in acidity exceeds pH buffer system, the blood will really be sour.Along with the decrease in blood pH, breathing becomes deeper and faster as the body attempts to reduce excess acid in the blood by reducing the amount of carbon dioxide. In the end, the kidneys try to compensate for this situation by issuing more acid in the urine. But both mechanisms could be exceeded if the body is constantly producing too much acid, resulting in severe acidosis and end up with a coma.CauseCauses of metabolic acidosis can be grouped into three main groups:1. The amount of acid in the body can be increased if you consume an acid or a substance that is converted into acid. Most of the material that causes acidosis is considered toxic when eaten. Examples are methanol (wood alcohol) and anti-freeze (ethylene glycol). An overdose of aspirin can cause metabolic acidosis.2. The body can produce more acid through metabolism.The body can produce excessive acid as a result of some disease; one of which is diabetes mellitus type I. If diabetes is not controlled properly, the body will break down fat and produces acids called ketones. Excessive acid is also found in an advanced stage of shock, where lactic acid is formed from the metabolism of sugars.3. Metabolic acidosis can occur if the kidneys are unable to remove the acids in the proper amount. Even the amount of acid that can cause acidosis normalpun if the kidneys are not functioning normally. Abnormalities of renal function is known as renal tubular acidosis, which can occur in patients with renal failure or patients with disorders that affect the kidneys' ability to dispose of acid.The main causes of metabolic acidosis: renal failure renal tubular acidosis (renal deformities) Diabetic Ketoacidosis Lactic acidosis (increased lactic acid) toxic materials such as ethylene glycol, an overdose of salicylate, methanol, paraldehid, asetazolamid or ammonium chloride Loss of bases (eg bicarbonate) through the digestive tract due to diarrhea, ileostomy or colostomy.SymptomMild metabolic acidosis may not cause symptoms, but sufferers usually experience nausea, vomiting and fatigue. Breathing becomes deeper or a little faster, but most people do not pay attention to this. In line with the worsening acidosis, the patient began to feel fatigue, drowsiness, nausea and experiencing the confusion. If acidosis worsens, blood pressure can drop, causing shock, coma and death.DiagnosisDiagnosis is usually made based on the results acidosis blood pH measurements were taken from the arterial blood (radial artery in the wrist). Arterial blood is used as an example because it is not accurate venous blood to measure blood pH. To find the cause, we measured levels of carbon dioxide and bicarbonate in the blood. It may take additional tests to help determine the cause.For example, high blood sugar levels and the presence of ketones in the urine usually indicates an uncontrolled diabetes. Presence of toxic materials in the blood showed that metabolic acidosis is caused by poisoning or overdose. Sometimes urine examined microscopically and urine pH measurements.TreatmentTreatment depends on the cause of metabolic acidosis. For example, diabetes is controlled with insulin or poisoning treated by removing toxic materials from the blood. Sometimes need dialysis to treat severe overdose or poisoning. Metabolic acidosis can be treated directly. In the event of a mild acidosis, which required only intravenous fluids and treatment of the cause. In case of severe acidosis, bicarbonate may be given intravenously.Examples of cases1. Yoshiharu Kubo, a football player, suddenly collapsed on the field after scoring. After blood gas analysis, it was found the following data:- PH 7.2 (down)- HCO3-15 mEq / L (down)- PCO2 38 mmHg (normal)- PO2 100 mmHg (normal)- Base excess -13 (down)From the above data we can conclude that metabolic acidosis mas Yoshiharu terkompensata yet. PH value drops indicates acidosis. HCO3-down value indicating the cause of primary metabolic process. PCO2 values were normal indicates not terkompensasinya acidosis. normal pO2 values indicate the absence of hypoxia.2. Half an hour later, blood gas analysis Yoshiharu mas is as follows:- PH 7.28 (down)- HCO3-9 mEq / L (down)- PCO2 20 mmHg (down)- PO2 100 mmHg (normal)- Base excess -17 (down)Conditions mas Yoshiharu now is terkompensata metabolic acidosis without hypoxia. PCO2 values have dropped called "have terkompensata". PO2 values were normal hypoxia signaling yet.Severe metabolic acidosis occurs when:- PH <7.2- 7.45 and HCO3-HCO3-> 28 mEqExamples of cases- PH 7.58 (up)- HCO3-29 mEq / L (up)- PO2 100 mEq / L (normal)- PCO2 38 mEq / L (normal)- Base excess + 6 (up)The diagnosis was metabolic alkalosis without hypoxia.-------------------------------- Respiratory alkalosisRespratorik alkalosis occurs when hyperventilation. Hyperventilation causes CO2 levels down the body, causing the body to compensate by lowering pH H + retention by the kidneys that HCO3-absorption is reduced. Remember, when the pH means higher [H +] down.The clinical- Patients often yawning- Shortness of breath more quickly and in- Head feels light- Paresthesia and tingling around the mouthCauses may be acute central nervous stimulation on cerebral tumors, encephalitis, and intoxication. The cause of chronic lung disease can be chronic.Examples of cases- PH 7.6 (up)- HCO3-24 mEq / L (normal)- PO2 65 mEq / L (down)- PCO2 25 mEq / L (down)- Base excess + 4 (up)The diagnosis was respiratory alkalosis with hypoxia.
