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Acidosis And Alkalosis

Acidosis

Acidosis

For acidosis referring to acidity of the urine, see renal tubular acidosis. "Acidemia" redirects here. It is not to be confused with Academia. Acidosis is a process causing increased acidity in the blood and other body tissues (i.e., an increased hydrogen ion concentration). If not further qualified, it usually refers to acidity of the blood plasma. The term acidemia describes the state of low blood pH, while acidosis is used to describe the processes leading to these states. Nevertheless, the terms are sometimes used interchangeably. The distinction may be relevant where a patient has factors causing both acidosis and alkalosis, wherein the relative severity of both determines whether the result is a high, low, or normal pH. Acidosis is said to occur when arterial pH falls below 7.35 (except in the fetus – see below), while its counterpart (alkalosis) occurs at a pH over 7.45. Arterial blood gas analysis and other tests are required to separate the main causes. The rate of cellular metabolic activity affects and, at the same time, is affected by the pH of the body fluids. In mammals, the normal pH of arterial blood lies between 7.35 and 7.50 depending on the species (e.g., healthy human-arterial blood pH varies between 7.35 and 7.45). Blood pH values compatible with life in mammals are limited to a pH range between 6.8 and 7.8. Changes in the pH of arterial blood (and therefore the extracellular fluid) outside this range result in irreversible cell damage.[1] Signs and symptoms[edit] General symptoms of acidosis.[2] These usually accompany symptoms of another primary defect (respiratory or metabolic). Nervous system involvement may be seen with acidosis and occurs more often with respiratory acidosis than with metabolic acidosis. Signs and symptoms that may be seen i Continue reading >>

Acidosis Vs. Alkalosis

Acidosis Vs. Alkalosis

In this lesson, we're going to learn about acidosis and alkalosis. We'll take a look at the causes, signs, and symptoms that are associated with each condition. Balanced Blood We are constantly having to find balance in our lives. From balancing work and play time to saving and spending money, sleep and awake time. Well, ideally at least. We do this because we know that we function best when we're balanced. There are many similar balances that are going on inside of our bodies. An important balance that must be maintained to allow us to function properly is the balance between acids and bases in our bodies. When these are balanced, the acids pair up with the bases, and our blood is close to neutral. If too much acid is in the blood, then we experience acidosis. If too much base is in the blood, we experience alkalosis. Acidosis and alkalosis are caused by different conditions in our bodies, and they can cause different problems to occur. Acidosis Acidosis results from the build-up of acids in the blood or from the loss of base in the blood. Acids are put into our bloodstream through two systems in the body: the digestive system and the respiratory system. Acidosis that occurs from the digestive system is referred to as metabolic acidosis. In this instance, acids accumulate in the blood due to consumption of acidic foods or foods that are broken down into acids, excess acids being produced during metabolism, kidneys not properly removing acid from the bloodstream during filtration, or production of acid by the body due to other medical conditions, such as diabetes. The other possible way to develop acidosis is by the malfunctioning of the respiratory system, which we refer to as respiratory acidosis. This can happen if breathing is extremely slow or shallow, the lungs do Continue reading >>

Acid-base Disorders - Endocrine And Metabolic Disorders - Merck Manuals Professional Edition

Acid-base Disorders - Endocrine And Metabolic Disorders - Merck Manuals Professional Edition

(Video) Overview of Acid-Base Maps and Compensatory Mechanisms By James L. Lewis, III, MD, Attending Physician, Brookwood Baptist Health and Saint Vincents Ascension Health, Birmingham Acid-base disorders are pathologic changes in carbon dioxide partial pressure (Pco2) or serum bicarbonate (HCO3) that typically produce abnormal arterial pH values. Acidosis refers to physiologic processes that cause acid accumulation or alkali loss. Alkalosis refers to physiologic processes that cause alkali accumulation or acid loss. Actual changes in pH depend on the degree of physiologic compensation and whether multiple processes are present. Primary acid-base disturbances are defined as metabolic or respiratory based on clinical context and whether the primary change in pH is due to an alteration in serum HCO3 or in Pco2. Metabolic acidosis is serum HCO3< 24 mEq/L. Causes are Metabolic alkalosis is serum HCO3> 24 mEq/L. Causes are Respiratory acidosis is Pco2> 40 mm Hg (hypercapnia). Cause is Decrease in minute ventilation (hypoventilation) Respiratory alkalosis is Pco2< 40 mm Hg (hypocapnia). Cause is Increase in minute ventilation (hyperventilation) Compensatory mechanisms begin to correct the pH (see Table: Primary Changes and Compensations in Simple Acid-Base Disorders ) whenever an acid-base disorder is present. Compensation cannot return pH completely to normal and never overshoots. A simple acid-base disorder is a single acid-base disturbance with its accompanying compensatory response. Mixed acid-base disorders comprise 2 primary disturbances. Compensatory mechanisms for acid-base disturbances cannot return pH completely to normal and never overshoot. Primary Changes and Compensations in Simple Acid-Base Disorders 1.2 mm Hg decrease in Pco2 for every 1 mmol/L decrease in HC Continue reading >>

Disorders Of Acid-base Balance

Disorders Of Acid-base Balance

Module 10: Fluid, Electrolyte, and Acid-Base Balance 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. Figure 1. Symptoms of acidosis affect several organ systems. Both acidosis and alkalosis can be diagnosed using a blood test. Metabolic Acidosis: Primary Bic Continue reading >>

Metabolic Alkalosis

Metabolic Alkalosis

Practice Essentials Metabolic alkalosis is a primary increase in serum bicarbonate (HCO3-) concentration. This occurs as a consequence of a loss of H+ from the body or a gain in HCO3-. In its pure form, it manifests as alkalemia (pH >7.40). As a compensatory mechanism, metabolic alkalosis leads to alveolar hypoventilation with a rise in arterial carbon dioxide tension (PaCO2), which diminishes the change in pH that would otherwise occur. Normally, arterial PaCO2 increases by 0.5-0.7 mm Hg for every 1 mEq/L increase in plasma bicarbonate concentration, a compensatory response that is very quick. If the change in PaCO2 is not within this range, then a mixed acid-base disturbance occurs. For example, if the increase in PaCO2 is more than 0.7 times the increase in bicarbonate, then metabolic alkalosis coexists with primary respiratory acidosis. Likewise, if the increase in PaCO2 is less than the expected change, then a primary respiratory alkalosis is also present. The first clue to metabolic alkalosis is often an elevated bicarbonate concentration that is observed when serum electrolyte measurements are obtained. Remember that an elevated serum bicarbonate concentration may also be observed as a compensatory response to primary respiratory acidosis. However, a bicarbonate concentration greater than 35 mEq/L is almost always caused by metabolic alkalosis. Metabolic alkalosis is diagnosed by measuring serum electrolytes and arterial blood gases. If the etiology of metabolic alkalosis is not clear from the clinical history and physical examination, including drug use and the presence of hypertension, then a urine chloride ion concentration can be obtained. Calculation of the serum anion gap may also help to differentiate between primary metabolic alkalosis and metabolic compe Continue reading >>

Csf Bicarbonate Regulation In Respiratory Acidosis And Alkalosis.

Csf Bicarbonate Regulation In Respiratory Acidosis And Alkalosis.

CSF bicarbonate regulation in respiratory acidosis and alkalosis. CSF bicarbonate regulation was studied in respiratory acidosis and alkalosis of 4h duration in antsthetized dogs. PCO2, pH, HCO3, ammonia, and lactate in CSF and arterial and safittal sinus bloof were measured when equal volumes of saline or acetazolamide (8 mg) were injected into lateral cerebral ventricles. The brain CO2 dissociation curve was determined at the end of all experiments. CSF and arterial bicarbonate increased 11.8 and 5.9 meg/l, respectively, in acidosis. Acetazolamide limited the rise in CSF bicarbonate to 4.2 meg/l, and prevented the CSF bicarbonate increase associated with hyperammonemia. During alkalosis CSF bicarbonate fell 6.5 meg/l and CSF lactate increased almost 2 meg/l while arterial bicarbonate fell 5.7 meg/l and lactate remained unchanged. Thus plasma bicarbonate changes account for some of the CSF unchanged. Thus plasma bicarbonate changes account for some of the CSF bicarbonate alterations in respiratory acid-base-disturbances. In acidosis additional CSF bicarbonate is formed by the choroid plexus and glial cells on the inner and outer surfaces of the brain--a reaction catalyzed by the locally present carbonic anhydrase. In alkalosis the greater fall in CSF bicarbonate than blood is due to selective brain and CSF lactic acidosis. Continue reading >>

Consequences Of Respiratory Acidosis And Alkalosis - Deranged Physiology

Consequences Of Respiratory Acidosis And Alkalosis - Deranged Physiology

Consequences of Respiratory Acidosis and Alkalosis So, your PaCO2 is, oh say 150mmHg. So what. What could go wrong? Consequences of Respiratory Acid-Base Disorders Increased respiratory stimulus (maximum at 65mmHg) Right shift of the oxyhaemoglobin dissociation curve With a chronically raised PaCO2, a decrease in 2,3-DPG drives the curve back to the left Cerebral vasodilation; headache and increased intracranial pressure CNS depression and a decreased level of consciousness Left shift of oxyhemoglobin dissociation curve Interestingly, none of this has ever made it into the fellowship paper. One might suppose that such fundamental concepts are better interrogated in the primary exam. For those who were for whatever reason exempted from this great barrier, apocryphal pages are available in the section concerned with acid-base disturbances . Specific chapters offer detailed digressions regarding physiological effects of carbon dioxide , buffering in acute respiratory acid-base disturbances and the physiology of carbon dioxide storage and transport . Continue reading >>

Simple Method Of Acid Base Balance Interpretation

Simple Method Of Acid Base Balance Interpretation

A FOUR STEP METHOD FOR INTERPRETATION OF ABGS Usefulness This method is simple, easy and can be used for the majority of ABGs. It only addresses acid-base balance and considers just 3 values. pH, PaCO2 HCO3- Step 1. Use pH to determine Acidosis or Alkalosis. ph < 7.35 7.35-7.45 > 7.45 Acidosis Normal or Compensated Alkalosis Step 2. Use PaCO2 to determine respiratory effect. PaCO2 < 35 35 -45 > 45 Tends toward alkalosis Causes high pH Neutralizes low pH Normal or Compensated Tends toward acidosis Causes low pH Neutralizes high pH Step 3. Assume metabolic cause when respiratory is ruled out. You'll be right most of the time if you remember this simple table: High pH Low pH Alkalosis Acidosis High PaCO2 Low PaCO2 High PaCO2 Low PaCO2 Metabolic Respiratory Respiratory Metabolic If PaCO2 is abnormal and pH is normal, it indicates compensation. pH > 7.4 would be a compensated alkalosis. pH < 7.4 would be a compensated acidosis. These steps will make more sense if we apply them to actual ABG values. Click here to interpret some ABG values using these steps. You may want to refer back to these steps (click on "linked" steps or use "BACK" button on your browser) or print out this page for reference. Step 4. Use HC03 to verify metabolic effect Normal HCO3- is 22-26 Please note: Remember, the first three steps apply to the majority of cases, but do not take into account: the possibility of complete compensation, but those cases are usually less serious, and instances of combined respiratory and metabolic imbalance, but those cases are pretty rare. "Combined" disturbance means HCO3- alters the pH in the same direction as the PaCO2. High PaCO2 and low HCO3- (acidosis) or Low PaCO2 and high HCO3- (alkalosis). Continue reading >>

Metabolic And Respiratory Acidosis And Alkalosis

Metabolic And Respiratory Acidosis And Alkalosis

There are two main types of pH imbalances in the body: acidosis and alkalosis. An increase in H+ ion levels in the blood causes pH levels to fall resulting in acidosis. A decrease in H+ levels causes pH levels to rise, making the blood more basic, or alkaline. These conditions can be caused by two kinds of disturbances to the buffers that control the body’s pH levels, which alter the acid-base balance. Metabolic and respiratory acidosis and alkalosis are the results of disruptions to the bicarbonate and carbonic acid components of the chemical buffers. Metabolic and respiratory acidosis result when pH levels fall due to an increase in H+ ions or a loss of bases causing the bodily fluids to become slightly acidic. Insufficient bicarbonate levels lower the pH levels of fluids in the digestive tract, resulting in metabolic acidosis. Respiratory acidosis is caused by excessive carbonic acid in the respiratory system, which lowers pH levels through the retention of CO2. Alkalosis is the result of opposite changes to the acid-base balance: excessive bicarbonate levels in the digestive system increases pH as H+ ion concentrations decrease, which causes fluids to become more basic. Insufficient carbonic acid levels are caused by excessive exhalation of CO2, resulting in respiratory alkalosis. Treatment for metabolic and respiratory acidosis and alkalosis varies depending on the underlying cause of the imbalance. Respiratory acidosis caused by hypoventilation can be treated with oxygen therapy and the help of breathing machines to help restore normal oxygen/carbon dioxide exchange, allowing the kidneys time to increase production of bicarbonate and reestablish the acid-base balance of the blood. Respiratory alkalosis caused by hyperventilation can be treated with inhalation of 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 >>

Ketoacid Production In Acute Respiratory And Metabolic Acidosis And Alkalosis In Rats.

Ketoacid Production In Acute Respiratory And Metabolic Acidosis And Alkalosis In Rats.

Ketoacid production in acute respiratory and metabolic acidosis and alkalosis in rats. Department of Medicine, University of Vermont College of Medicine, Burlington 05405. Am J Physiol. 1989 Mar;256(3 Pt 2):F437-45. Metabolic acidosis inhibits and alkalosis enhances ketoacid production in ketotic humans and animals. To compare these effects with those of superimposed respiratory acid-base disturbances, ketone output was evaluated in awake ketotic rats during metabolic (intravenous infusions of HCl or NaHCO3) or respiratory (hyper or hypocapnia) disorders. With decreases in blood pH of 0.1-0.2 units over 3 h, blood ketone concentrations significantly decreased an average of 1.9 mM (metabolic) and 1.1 mM (respiratory) and urinary ketone excretion rates significantly decreased by 1.3 mumol/min (metabolic). With increases in systemic pH, blood ketone concentrations and urinary ketone excretion rates were significantly increased. Changes in blood pH correlated with changes in urinary ketone excretion rates in both metabolic (r = 0.87) and respiratory (r = 0.67) acid-base disturbances. The alterations occurred promptly and were rapidly reversible. These findings indicate that modest changes in systemic pH from metabolic or respiratory acid-base disturbances modify net ketoacid production in ketotic rats, confirm pH control of endogenous acid output as an acid-base regulator, and show that systemic pH, not bicarbonate concentration, mediates the process. Continue reading >>

Changes In Brain Ecf Ph During Metabolic Acidosis And Alkalosis: A Microelectrode Study.

Changes In Brain Ecf Ph During Metabolic Acidosis And Alkalosis: A Microelectrode Study.

Changes in brain ECF pH during metabolic acidosis and alkalosis: a microelectrode study. Javaheri S, et al. J Appl Physiol Respir Environ Exerc Physiol. 1983. J Appl Physiol Respir Environ Exerc Physiol. 1983 Dec;55(6):1849-53. We used pH-sensitive double-barreled microelectrodes to measure brain extracellular fluid (ECF) pH in anesthetized dogs during isocapnic infusion acidosis (HCl) and alkalosis (Na2CO3) of 45-60 min duration. The diameter of the tips of these electrodes varied from less than 1 to 27 micron and were placed 5 mm below the surface of the parietal cortex. In group I (metabolic acidosis, n = 5) mean plasma and brain ECF pH fell significantly by 0.221 and 0.025, respectively, with changes in brain ECF pH being 11.3% of those noted in plasma. In group II (metabolic alkalosis, n = 5) mean plasma and brain ECF pH rose significantly by 0.170 and 0.049, respectively, with changes in brain ECF pH being 28.8% of those noted in plasma. Mean arterial and sagittal venous PCO2 and cisternal cerebrospinal fluid (CSF) acid-base variables did not change significantly during acid or base infusion. We conclude that during transients of isocapnic metabolic acid-base perturbations ionic gradients exist between brain ECF and CSF and that changes in brain ECF pH measured by microelectrodes follow the changes in plasma pH. These pH changes may play an important role in respiratory adaptations of acute metabolic acidosis and alkalosis. Continue reading >>

Acidosis And Alkalosis

Acidosis And Alkalosis

Acidosis is a condition caused by removal of bicarbonateor an increase in carbonic acid in blood. The net result is a disturbancein the carbonic acid-bicarbonate equilibrium to produce an excess [H+] inblood causing lower blood pH. Metabolic acidosis can occur as a result ofdiabetes, starvation and high fat diet all of which leads to the productionof ketones in the blood. Ketones bind & remove bicarbonate. If not controlled it can be fatal [see ketoacidosis and diabetesin the further reading folder]. Alkalosis occurs when [bicarbonate] increases forcing theequilibrium to remove protons from blood causing blood pH to rise. So pHbecomes alkaline leading to vomiting, nausea, headache. Temporary metabolic alkalosis occurs when there is an intakeof sodium bicarbonate e.g. if large amounts are taken for acid in the stomach.Respiratory alkalosis can be induced by hyperventilation i.e. excessiveexhalation of carbon dioxide from lungs too quickly causing too great aloss of H+ from the large reservoir. Anything that causes sustained rapidbreathing can induce temporary alkalosis, e.g. hysteria (pop concert), hotbaths, training. Athletes such as marathon runners learn to control breathingso as to minimise alkalosis. Sprinters and swimmers who understand biochemistrytune their bodies for maximum effort. Strenuous bursts of muscle activityproduce high levels of lactic acid as glucose is broken down for energy.Lactic acid can lower the pH of blood and cause muscle cramp/fatigue. To counteract this, athletes will prepare by rapid deepbreathing for 30-40 seconds before the race to hyperventilate and introducetemporary alkaline conditions that will help to neutralise the acidity arisingfrom lactic acid. For more detail on this topicsee the text book page 57 Continue reading >>

Acidosis And Alkalosis

Acidosis And Alkalosis

Find an explanation of your pathology test Acidosis and alkalosis are terms used to describe the abnormal conditions when a patients blood pH does not fall within the healthy range. Measuring the pH of blood is a way of determining how acidic or basic (alkaline) the blood is. Normal blood pH must be maintained within a narrow range of 7.35 - 7.45 to ensure that metabolic processes function properly and the right amount of blood is delivered to the tissues. Many diseases or situations can cause a patients blood pH to fall outside of these limits. In the human body, normal metabolism generates large quantities of acids that must be eliminated to maintain a normal pH balance. Most of the acid is carbonic acid which is produced when carbon dioxide (CO2) combines with water in the body. Lesser quantities of lactic acid, ketoacids and other organic acids are also produced. This balance can be disrupted by a build-up of an acid or a base (alkali) or by an increased loss of an acid or a base (see Figure 1, below). Acidosis occurs when blood pH falls below 7.35 Alkalosis occurs when blood pH rises above 7.45 Both of these conditions act as an alarm to the body; they trigger actions intended to restore the pH balance and 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 CO2 (carbon dioxide). Within physical limits, the body can raise and lower the rate of breathing to alter the amount of CO2 that is breathed out. This can affect blood pH within seconds or minutes. The kidneys excrete some acids in the urine, and they produce and regulate the retention of HCO3- (bicarbonate), a base that increases the bloods pH or alkalinity. Changes in HCO3- concentration occur 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 >>

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