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What Are The Causes Of Metabolic Acidosis And Alkalosis?

Acid-base Imbalances: Metabolic Acidosis And Alkalosis

Acid-base Imbalances: Metabolic Acidosis And Alkalosis

Acid-Base Imbalances: Metabolic Acidosis and Alkalosis; Respiratory Acidosis and Alkalosis The hydrogen ion concentration ([H+]) of the body, described as the pH or negative log of the [H+], is maintained in a narrow range to promote health and homeostasis. The body has many regulatory mechanisms that counteract even a slight deviation from normal pH. An acid-base imbalance can alter many physiological processes and lead to serious problems or, if left untreated, to coma and death. A pH below 7.35 is considered acidosis and above 7.45 is alkalosis. Alterations in hydrogen ion concentration can be metabolic or respiratory in origin or they may have a mixed origin. Metabolic acidosis, a pH below 7.35, results from any nonpulmonary condition that leads to an excess of acids over bases. Renal patients with chronic acidemia may show signs of skeletal problems as calcium and phosphate are released from bone to help with the buffering of acids. Children with chronic acidosis may show signs of impaired growth. Metabolic alkalosis, a pH above 7.45, results from any nonpulmonary condition that leads to an excess of bases over acids. Metabolic alkalosis results from one of two mechanisms: an excess of bases or a loss of acids. Patients with a history of congestive heart failure and hypertension who are on sodium-restricted diets and diuretics are at greatest risk for metabolic alkalosis. Metabolic alkalosis can also be caused by prolonged vomiting, hyperaldosteronism, and diuretic therapy. Respiratory acidosis is a pH imbalance that results from alveolar hypoventilation and an accumulation of carbon dioxide. It can be classified as either acute or chronic. Acute respiratory acidosis is associated with a sudden failure in ventilation. Chronic respiratory acidosis is seen in patient Continue reading >>

Metabolic Alkalosis

Metabolic Alkalosis

Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35–7.45). This is the result of decreased hydrogen ion concentration, leading to increased bicarbonate, or alternatively a direct result of increased bicarbonate concentrations. Terminology[edit] Alkalosis refers to a process by which the pH is increased. Alkalemia refers to a pH which is higher than normal, specifically in the blood. Causes[edit] The causes of metabolic alkalosis can be divided into two categories, depending upon urine chloride levels.[1] Chloride-responsive (Urine chloride < 10 mEq/L)[edit] Loss of hydrogen ions - Most often occurs via two mechanisms, either vomiting or via the kidney. Vomiting results in the loss of hydrochloric acid (hydrogen and chloride ions) with the stomach contents. In the hospital setting this can commonly occur from nasogastric suction tubes. Severe vomiting also causes loss of potassium (hypokalaemia) and sodium (hyponatremia). The kidneys compensate for these losses by retaining sodium in the collecting ducts at the expense of hydrogen ions (sparing sodium/potassium pumps to prevent further loss of potassium), leading to metabolic alkalosis.[2] Congenital chloride diarrhea - rare for being a diarrhea that causes alkalosis instead of acidosis.[3] Contraction alkalosis - This results from a loss of water in the extracellular space, such as from dehydration. Decreased extracellular volume triggers the renin-angiotensin-aldosterone system, and aldosterone subsequently stimulates reabsorption of sodium (and thus water) within the nephron of the kidney. However, a second action of aldosterone is to stimulate renal excretion of hydrogen ions (while retaining bicarbonate), and it is this loss of hydrogen ions that raises Continue reading >>

Metabolic Acidosis: Causes, Symptoms, And Treatment

Metabolic Acidosis: Causes, Symptoms, And Treatment

The Terrible Effects of Acid Acid corrosion is a well-known fact. Acid rain can peel the paint off of a car. Acidifying ocean water bleaches and destroys coral reefs. Acid can burn a giant hole through metal. It can also burn holes, called cavities, into your teeth. I think I've made my point. Acid, regardless of where it's at, is going to hurt. And when your body is full of acid, then it's going to destroy your fragile, soft, internal organs even more quickly than it can destroy your bony teeth and chunks of thick metal. What Is Metabolic Acidosis? The condition that fills your body with proportionately too much acid is known as metabolic acidosis. Metabolic acidosis refers to a physiological state characterized by an increase in the amount of acid produced or ingested by the body, the decreased renal excretion of acid, or bicarbonate loss from the body. Metabolism is a word that refers to a set of biochemical processes within your body that produce energy and sustain life. If these processes go haywire, due to disease, then they can cause an excess production of hydrogen (H+) ions. These ions are acidic, and therefore the level of acidity in your body increases, leading to acidemia, an abnormally low pH of the blood, <7.35. The pH of the blood mimics the overall physiological state in the body. In short, a metabolic process is like a power plant producing energy. If a nuclear power plant goes haywire for any reason, then we know what the consequences will be: uncontrolled and excessive nuclear energetic reactions leading to the leakage of large amounts of radioactive material out into the environment. In our body, this radioactive material is acid (or hydrogen ions). Acidemia can also occur if the kidneys are sick and they do not excrete enough hydrogen ions out of th Continue reading >>

Causes Of Metabolic Alkalosis

Causes Of Metabolic Alkalosis

INTRODUCTION Metabolic alkalosis, a disorder that elevates the serum bicarbonate, can result from several mechanisms: intracellular shift of hydrogen ions; gastrointestinal loss of hydrogen ions; excessive renal hydrogen ion loss; administration and retention of bicarbonate ions; or volume contraction around a constant amount of extracellular bicarbonate (contraction alkalosis) (table 1) [1-4]. Hydrogen ions are derived from the dissociation of water into hydrogen and hydroxyl ions; therefore, when hydrogen ions are removed from the extracellular fluid, the remaining hydroxyl ion combines with carbon dioxide to form bicarbonate. Gastrointestinal and renal hydrogen loss is usually accompanied by the loss of chloride and potassium, resulting in hypochloremia and hypokalemia. Patients with preserved renal function will most often rapidly excrete excess bicarbonate in the urine. Thus, metabolic alkalosis can only persist if the ability to excrete excess bicarbonate in the urine is impaired due to one of the following causes: hypovolemia; reduced effective arterial blood volume (due, for example, to heart failure or cirrhosis); chloride depletion; hypokalemia; reduced glomerular filtration rate; hyperaldosteronism; or combinations of these factors [3,5,6]. The causes of metabolic alkalosis will be reviewed here. The pathogenesis, evaluation, and treatment of this disorder are discussed separately. (See "Pathogenesis of metabolic alkalosis" and "Clinical manifestations and evaluation of metabolic alkalosis" and "Treatment of metabolic alkalosis".) INTRACELLULAR SHIFT OF HYDROGEN Metabolic alkalosis can be generated by a shift of hydrogen ions into the cells. This most often occurs in patients with potassium deficits and hypokalemia. This may be an important pathophysiologic m Continue reading >>

Alkalosis

Alkalosis

The kidneys and lungs maintain the proper balance (proper pH level) of chemicals called acids and bases in the body. Decreased carbon dioxide (an acid) level or increased bicarbonate (a base) level makes the body too alkaline, a condition called alkalosis. There are different types of alkalosis. These are described below. Respiratory alkalosis is caused by a low carbon dioxide level in the blood. This can be due to: Fever Being at a high altitude Lack of oxygen Liver disease Metabolic alkalosis is caused by too much bicarbonate in the blood. It can also occur due to certain kidney diseases. Hypochloremic alkalosis is caused by an extreme lack or loss of chloride, such as from prolonged vomiting. Hypokalemic alkalosis is caused by the kidneys' response to an extreme lack or loss of potassium. This can occur from taking certain water pills (diuretics). Compensated alkalosis occurs when the body returns the acid-base balance to normal in cases of alkalosis, but bicarbonate and carbon dioxide levels remain abnormal. Continue reading >>

Acidosis/alkalosis

Acidosis/alkalosis

This article waslast modified on 31 January 2019. Acidosis and alkalosis are terms used to describe abnormal conditions when a patients blood pH may not fall within the healthy range. Measuring the hydrogen ion concentration, and calculating the pH , of blood is a way of finding out how acidic or alkaline the blood is. Normal blood pH must be within a narrow range of 7.35-7.45 so that the bodys metabolic processes can work properly and can deliver the right amount of oxygen to tissues. Many diseases and other conditions can cause a patients blood pH to fall outside of these healthy limits. In the human body, normal metabolism generates large quantities of acids (effectively compounds that produce a free hydrogen ion) that must be removed to keep a normal pH balance. Disruption of this balance can be caused by a build-up of acid or alkali (base) or by an increased loss of acid or alkali (see the diagram of taps and drains below). Alkalis, or bases, are compounds that remove a free hydrogen ion. Acidosis occurs when blood pH falls below 7.35, indicating an increase in hydrogen ion concentration. Alkalosis occurs when blood pH rises above 7.45, indicating a reduction in hydrogen ion concentration. Both of these conditions act as an alarm to the body; they trigger actions intended to restore the balance and to return the blood pH to its normal range. The major organs involved in regulating blood pH are the lungs and the kidneys. The lungs flush acid out of the body by exhaling carbon dioxide (CO2), which forms an acid when in solution (dissolved in the blood). Within physical limits, the body can raise and lower the rate of breathing to alter the amount of carbon dioxide that is breathed out. This can affect blood pH within seconds to minutes. The kidneys remove some acids Continue reading >>

Types Of Disturbances

Types Of Disturbances

The different types of acid-base disturbances are differentiated based on: Origin: Respiratory or metabolic Primary or secondary (compensatory) Uncomplicated or mixed: A simple or uncomplicated disturbance is a single or primary acid-base disturbance with or without compensation. A mixed disturbance is more than one primary disturbance (not a primary with an expected compensatory response). Acid-base disturbances have profound effects on the body. Acidemia results in arrythmias, decreased cardiac output, depression, and bone demineralization. Alkalemia results in tetany and convulsions, weakness, polydipsia and polyuria. Thus, the body will immediately respond to changes in pH or H+, which must be kept within strict defined limits. As soon as there is a metabolic or respiratory acid-base disturbance, body buffers immediately soak up the proton (in acidosis) or release protons (alkalosis) to offset the changes in H+ (i.e. the body compensates for the changes in H+). This is very effective so minimal changes in pH occur if the body is keeping up or the acid-base abnormality is mild. However, once buffers are overwhelmed, the pH will change and kick in stronger responses. Remember that the goal of the body is to keep hydrogen (which dictates pH) within strict defined limits. The kidney and lungs are the main organs responsible for maintaining normal acid-base balance. The lungs compensate for a primary metabolic condition and will correct for a primary respiratory disturbance if the disease or condition causing the disturbance is resolved. The kidney is responsible for compensating for a primary respiratory disturbance or correcting for a primary metabolic disturbance. Thus, normal renal function is essential for the body to be able to adequately neutralize acid-base abnor Continue reading >>

Acid-base Balance

Acid-base Balance

Patient professional reference Professional Reference articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use. You may find the Arterial Blood Gases article more useful, or one of our other health articles. Disorders of acid-base balance can lead to severe complications in many disease states.[1]Arterial blood pH is normally closely regulated to between 7.35 and 7.45. Maintaining the pH within these limits is achieved by bicarbonate, other buffers, the lungs and the kidneys. Primary changes in bicarbonate are metabolic and primary changes in carbon dioxide are respiratory. In the absence of any significant respiratory disease or hyperventilation, the primary cause is much more likely to be metabolic. However, central hypoventilation (eg, caused by CNS disturbance such as stroke, head injury or brain tumour) causes respiratory acidosis. In general, the kidneys compensate for respiratory causes and the lungs compensate for metabolic causes. Therefore, hyperventilation may be a cause of respiratory alkalosis or a compensatory mechanism for metabolic acidosis. Deep sighing respiration (Kussmaul breathing) is a common feature of acidosis (hyperventilation in an attempt to remove carbon dioxide) but may take some hours to appear. Investigations Analysis of arterial blood gases provides: pH: determines whether there is an overall acidosis or alkalosis. Venous pH is in practice as reliable as arterial pH. Carbon dioxide partial pressure (PaCO2): if raised with acidosis then the acidosis is respiratory. If decreased with alkalosis then the alkalosis is respiratory. Otherwise any change is compensatory. Standard bicarbonate (SBCe): analysis of blood gases provides a bicarbonate level whic Continue reading >>

Metabolic Acidosis

Metabolic Acidosis

Metabolic acidosis is primary reduction in bicarbonate (HCO3−), typically with compensatory reduction in carbon dioxide partial pressure (Pco2); pH may be markedly low or slightly subnormal. Metabolic acidoses are categorized as high or normal anion gap based on the presence or absence of unmeasured anions in serum. Causes include accumulation of ketones and lactic acid, renal failure, and drug or toxin ingestion (high anion gap) and GI or renal HCO3− loss (normal anion gap). Symptoms and signs in severe cases include nausea and vomiting, lethargy, and hyperpnea. Diagnosis is clinical and with ABG and serum electrolyte measurement. The cause is treated; IV sodium bicarbonate may be indicated when pH is very low. Acidemia (arterial pH < 7.35) results when acid load overwhelms respiratory compensation. Causes are classified by their effect on the anion gap (see The Anion Gap and see Table: Causes of Metabolic Acidosis). High anion gap acidosis Ketoacidosis is a common complication of type 1 diabetes mellitus (see diabetic ketoacidosis), but it also occurs with chronic alcoholism (see alcoholic ketoacidosis), undernutrition, and, to a lesser degree, fasting. In these conditions, the body converts from glucose to free fatty acid (FFA) metabolism; FFAs are converted by the liver into ketoacids, acetoacetic acid, and beta-hydroxybutyrate (all unmeasured anions). Ketoacidosis is also a rare manifestation of congenital isovaleric and methylmalonic acidemia. Lactic acidosis is the most common cause of metabolic acidosis in hospitalized patients. Lactate accumulation results from a combination of excess formation and decreased utilization of lactate. Excess lactate production occurs during states of anaerobic metabolism. The most serious form occurs during the various types o Continue reading >>

Metabolic Alkalosis

Metabolic Alkalosis

Metabolic alkalosis is common—half of all acid-base disorders as described in one study (1). This observation should not be surprising since vomiting, the use of chloruretic diuretics, and nasogastric suction are common among hospitalized patients. The mortality associated with severe metabolic alkalosis is substantial; a mortality rate of 45% in patients with an arterial blood pH of 7.55 and 80% when the pH was greater than 7.65 has been reported (2). Although this relationship is not necessarily causal, severe alkalosis should be viewed with concern, and correction by the appropriate intervention should be undertaken with dispatch when the arterial blood pH exceeds 7.55. Metabolic alkalosis occurs when a primary pathophysiologic process leads to the net accumulation of base within or the net loss of acid from the extracellular fluid (ECF); typically, the intracellular compartment becomes more acidic in potassium-depletion alkalosis (3). Unopposed by other primary acid-base disorders, metabolic alkalosis is recognized by increases in both arterial blood pH—alkalemia—and plasma bicarbonate concentration. The increase in arterial blood pH promptly, normally, and predictably depresses ventilation resulting in increased PaCO2 and the buffering of the alkalemia. The PaCO2 increases about 0.5 to 0.7 mmHg for every 1.0 mM increase in plasma HCO3 concentration (4). Although a PaCO2 greater than 55 mmHg is uncommon, compensatory increases to 60 mmHg have been documented in severe metabolic alkalosis. Failure of an appropriate compensatory increase in PaCO2 should be interpreted as a mixed acid-base disturbance in which a stimulus to hyperventilation—primary respiratory alkalosis—accompanies primary metabolic alkalosis. Classification and Definitions Metabolic alkalosi Continue reading >>

Extreme Metabolic Alkalosis In Intensive Care

Extreme Metabolic Alkalosis In Intensive Care

Go to: Case Reports A 60-year-old man presented to the emergency department with the complaints of weakness, difficulty in breathing, decreased appetite and absolute constipation for ten days. He was restless and disoriented. Hemodynamic parameters were normal. Investigations and systemic examination revealed severe metabolic alkalosis (pH 7.66) with dyselectrolytemia and volume depletion [Tables 1 and 2]. His respiratory and neurologic systems were unremarkable. The abdomen was distended and multiple fluid and air levels seen on an abdominal radiogram, confirmed sub acute intestinal obstruction. Despite denials of use of any diuretics or laxatives, when his regular medicines were checked, loop diuretics and combinations with potassium sparing diuretics were recovered-confirming long term diuretic abuse. All diuretics were removed from patient's bedside and patient was hydrated to achieve a central venous pressure (CVP) of at least 10 cm water (opening CVP 1 cm water) and a urine output of more than 1 ml/kg/hour. Obstipation was relieved by manual evacuation of hard dried up faeces - the cause of sub acute intestinal obstruction. Supplementation of potassium, chloride, sodium and magnesium led to improvement of serum electrolytes and resolution of alkalemia over 36 hours [Table 2]. The patient's respiratory distress, weakness and lassitude resolved. Patient was discharged after four days without any complains. Arterial Blood Gas values Continue reading >>

Alkalosis

Alkalosis

Your blood is made up of acids and bases. The amount of acids and bases in your blood can be measured on a pH scale. It’s important to maintain the correct balance between acids and bases. Even a slight change can cause health problems. Normally, your blood should have a slightly higher amount of bases than acids. Alkalosis occurs when your body has too many bases. It can occur due to decreased blood levels of carbon dioxide, which is an acid. It can also occur due to increased blood levels of bicarbonate, which is a base. This condition may also be related to other underlying health issues such as low potassium, or hypokalemia. The earlier it’s detected and treated, the better the outcome is. Acid-base balance » There are five main types of alkalosis. Respiratory alkalosis Respiratory alkalosis occurs when there isn’t enough carbon dioxide in your bloodstream. It’s often caused by: hyperventilation, which commonly occurs with anxiety high fever lack of oxygen salicylate poisoning being in high altitudes Metabolic alkalosis Metabolic alkalosis develops when your body loses too much acid or gains too much base. This can be attributed to: excess vomiting, which causes electrolyte loss overuse of diuretics a large loss of potassium or sodium in a short amount of time antacids accidental ingestion of bicarbonate, which can be found in baking soda laxatives alcohol abuse Hypochloremic alkalosis Hypochloremic alkalosis occurs when there’s a significant decline of chloride in your body. This can be due to prolonged vomiting or sweating. Chloride is an important chemical needed to maintain balance in bodily fluids, and it’s an essential part of your body’s digestive fluids. Hypokalemic alkalosis Hypokalemic alkalosis occurs when your body lacks the normal amount Continue reading >>

Metabolic Alkalosis

Metabolic Alkalosis

Metabolic alkalosis is primary increase in bicarbonate (HCO3−) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Common causes include prolonged vomiting, hypovolemia, diuretic use, and hypokalemia. Renal impairment of HCO3− excretion must be present to sustain alkalosis. Symptoms and signs in severe cases include headache, lethargy, and tetany. Diagnosis is clinical and with ABG and serum electrolyte measurement. The underlying condition is treated; oral or IV acetazolamide or hydrochloric acid is sometimes indicated. Metabolic alkalosis is bicarbonate HCO3− accumulation due to Regardless of initial cause, persistence of metabolic alkalosis indicates that the kidneys have increased their HCO3− reabsorption, because HCO3− is normally freely filtered by the kidneys and hence excreted. Volume depletion and hypokalemia are the most common stimuli for increased HCO3− reabsorption, but any condition that elevates aldosterone or mineralocorticoids (which enhance sodium [Na] reabsorption and potassium [K] and H+ excretion) can elevate HCO3−. Thus, hypokalemia is both a cause and a frequent consequence of metabolic alkalosis. Causes are listed; the most common are volume depletion (particularly when involving loss of gastric acid and chloride [Cl] due to recurrent vomiting or nasogastric suction) and diuretic use (see Table: Causes of Metabolic Alkalosis). Causes of Metabolic Alkalosis Cause Comments GI acid loss* Gastric acid loss due to vomiting or nasogastric suction Loss of HCl and acid coupled with contraction alkalosis due to release of aldosterone and subsequent resorption of HCO3 Congenital chloridorrhea Fecal Cl loss and HCO3 retention Villous adenoma Probably secondary to K depletion Renal a Continue reading >>

Metabolic Acidosis And Alkalosis

Metabolic Acidosis And Alkalosis

Page Index Metabolic Acidosis. Metabolic Alkalosis Emergency Therapy Treating Metabolic Acidosis Calculating the Dose Use Half the Calculated Dose Reasons to Limit the Bicarbonate Dose: Injected into Plasma Volume Fizzes with Acid Causes Respiratory Acidosis Raises Intracellular PCO2 Subsequent Residual Changes Metabolic Acidosis. The following is a brief summary. For additional information visit: E-Medicine (Christie Thomas) or Wikepedia Etiology: There are many causes of primary metabolic acidosis and they are commonly classified by the anion gap: Metabolic Acidosis with a Normal Anion Gap: Longstanding diarrhea (bicarbonate loss) Uretero-sigmoidostomy Pancreatic fistula Renal Tubular Acidosis Intoxication, e.g., ammonium chloride, acetazolamide, bile acid sequestrants Renal failure Metabolic Acidosis with an Elevated Anion Gap: lactic acidosis ketoacidosis chronic renal failure (accumulation of sulfates, phosphates, uric acid) intoxication, e.g., salicylates, ethanol, methanol, formaldehyde, ethylene glycol, paraldehyde, INH, toluene, sulfates, metformin. rhabdomyolysis For further details visit: E-Medicine (Christie Thomas). Treating Severe Metabolic Acidosis. The ideal treatment for metabolic acidosis is correction of the underlying cause. When urgency dictates more rapid correction, treatment is based on clinical considerations, supported by laboratory evidence. The best measure of the level of metabolic acidosis is the Standard Base Excess (SBE) because it is independent of PCO2. If it is decided to administer bicarbonate, the SBE and the size of the treatable space are used to calculate the dose required: Metabolic Alkalosis Etiology: Primary Metabolic alkalosis may occur from various causes including: Loss of acid via the urine, stools, or vomiting Transfer of Continue reading >>

Disorders Of Acid-base Balance

Disorders Of Acid-base Balance

Learning Objectives By the end of this section, you will be able to: Identify the three blood variables considered when making a diagnosis of acidosis or alkalosis Identify the source of compensation for blood pH problems of a respiratory origin Identify the source of compensation for blood pH problems of a metabolic/renal origin Normal arterial blood pH is restricted to a very narrow range of 7.35 to 7.45. A person who has a blood pH below 7.35 is considered to be in acidosis (actually, “physiological acidosis,” because blood is not truly acidic until its pH drops below 7), and a continuous blood pH below 7.0 can be fatal. Acidosis has several symptoms, including headache and confusion, and the individual can become lethargic and easily fatigued. A person who has a blood pH above 7.45 is considered to be in alkalosis, and a pH above 7.8 is fatal. Some symptoms of alkalosis include cognitive impairment (which can progress to unconsciousness), tingling or numbness in the extremities, muscle twitching and spasm, and nausea and vomiting. Both acidosis and alkalosis can be caused by either metabolic or respiratory disorders. As discussed earlier in this chapter, the concentration of carbonic acid in the blood is dependent on the level of CO2 in the body and the amount of CO2 gas exhaled through the lungs. Thus, the respiratory contribution to acid-base balance is usually discussed in terms of CO2 (rather than of carbonic acid). Remember that a molecule of carbonic acid is lost for every molecule of CO2 exhaled, and a molecule of carbonic acid is formed for every molecule of CO2 retained. Metabolic Acidosis: Primary Bicarbonate Deficiency Metabolic acidosis occurs when the blood is too acidic (pH below 7.35) due to too little bicarbonate, a condition called primary bicar Continue reading >>

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