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How Does The Body Try To Compensate For Metabolic Acidosis?

Respiratory Compensation

Respiratory Compensation

Metabolic Acidosis Respiratory compensation for metabolic disorders is quite fast (within minutes) and reaches maximal values within 24 hours. A decrease in Pco2 of 1 to 1.5 mm Hg should be observed for each mEq/L decrease of in metabolic acidosis.27 A simple rule for deciding whether the fall in Pco2 is appropriate for the degree of metabolic acidosis is that the Pco2 should be equal to the last two digits of the pH. For example, compensation is adequate if the Pco2 decreases to 28 when the pH is 7.28. Alternatively, the Pco2 can be predicted by adding 15 to the observed (down to a value of 12). Although reduction in Pco2 plays an important role in correcting any metabolic acidosis, evidence suggests that it may in some respects be counterproductive because it inhibits renal acid excretion. Fetoplacental Elimination of Metabolic Acid Load Fetal respiratory and renal compensation in response to changes in fetal pH is limited by the level of maturity and the surrounding maternal environment. However, although the placentomaternal unit performs most compensatory functions,3 the fetal kidneys have some, although limited, ability to contribute to the maintenance of fetal acid–base balance. The most frequent cause of fetal metabolic acidosis is fetal hypoxemia owing to abnormalities of uteroplacental function or blood flow (or both). Primary maternal hypoxemia or maternal metabolic acidosis secondary to maternal diabetes mellitus, sepsis, or renal tubular abnormalities is an unusual cause of fetal metabolic acidosis. Pregnant women, at least in late gestation, maintain a somewhat more alkaline plasma environment compared with that of nonpregnant control participants. This pattern of acid–base regulation in pregnant women is present during both resting and after maximal e Continue reading >>

The Quick And Dirty Guide To Acid Base Balance | Medictests.com

The Quick And Dirty Guide To Acid Base Balance | Medictests.com

Your patient has a ph of 6.9 Is he acidic or alkalotic? Your patient has a ph of 7.4 Is he acidic or alkalotic? Your patient has a ph of 7.7 Is he acidic or alkalotic? Your patient has a ph of 7.25 Is he acidic or alkalotic? Your patient has a ph of 7.43 Is he acidic or alkalotic? Your patient has a ph of 8.0 Is he acidic or alkalotic? 1. acidic 2. normal 3. Alkaline 4. Acidic 5. Normal 6. Alkaline You take in oxygen by inhaling, your body turns oxygen into carbon dioxide, you exhale and remove the carbon dioxide from your body. Carbon dioxide is "respiratory acid."When you're not breathing adequately, you are not getting rid of this "respiratory acid" and it builds up in the tissues. The extra CO2 molecules combine with water in your body to form carbonic acid and makes your pH go up. This is bad. We can measure the amount of respiratory acid in the arterial blood using blood gases. They measure the amount of each gas in your blood. We measure the pH, the amount of carbon dioxide (PaCO2) and the amount of oxygen in the blood (PaO2). PaCO2 is the partial pressure of carbon dioxide. We can measure it to see how much respiratory acid (CO2) there is in the blood. We use arterial blood gas tests to check it. How much respiratory acid (CO2) should there be? The normal value is 35-45 mmHg (mmHg just means millimeters of mercury, its a measurement of pressure.) The (a) in PaCO2 just stands for arterial. If you measured venous blood gasses, the levels are different and PvCO2 is used. If CO2 is HIGH, it means there is a buildup of respiratory acids because he's not breathing enough CO2 away. If your pH is acidic, and your CO2 is HIGH, its considered respiratory acidosis. If CO2 is LOW, it means there are not enough respiratory acids because he's probably hyperventilating too mu 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 >>

Intro To Arterial Blood Gases, Part 2

Intro To Arterial Blood Gases, Part 2

Arterial Blood Gas Analysis, Part 2 Introduction Acute vs. Chronic Respiratory Disturbances Primary Metabolic Disturbances Anion Gap Mixed Disorders Compensatory Mechanisms Steps in ABG Analysis, Part II Summary Compensatory Mechanisms Compensation refers to the body's natural mechanisms of counteracting a primary acid-base disorder in an attempt to maintain homeostasis. As you learned in Acute vs. Chronic Respiratory Disturbances, the kidneys can compensate for chronic respiratory disorders by either holding on to or dumping bicarbonate. With Chronic respiratory acidosis: Chronic respiratory alkalosis: the kidneys hold on to bicarbonate the kidneys dump bicarbonate With primary metabolic disturbances, the respiratory system compensates for the acid-base disorder. The lungs can either blow off excess acid (via CO2) to compensate for metabolic acidosis, or to a lesser extent, hold on to acid (via CO2) to compensate for metabolic alkalosis. With Metabolic acidosis: Metabolic alkalosis: ventilation increases to blow off CO2 ventilation decreases to hold on to CO2 The body's response to metabolic acidosis is predictable. With metabolic acidosis, respiration will increase to blow off CO2, thereby decreasing the amount of acid in the blood. Recall that with metabolic acidosis, central chemoreceptors are triggered by the low pH and increase the drive to breathe. For now, it is only important to learn (qualitatively) that there is a predictable compensatory response to metabolic acidosis. Later, during your 3rd or 4th year rotations, you might learn how to (quantitatively) determine if the compensatory response to metabolic acidosis is appropriate by using the Winter's Formula. The body's response to metabolic alkalosis is not as complete. This is because we would need to hypov Continue reading >>

Merck And The Merck Manuals

Merck And The Merck Manuals

Acidosis is caused by an overproduction of acid in the blood or an excessive loss of bicarbonate from the blood (metabolic acidosis) or by a buildup of carbon dioxide in the blood that results from poor lung function or depressed breathing (respiratory acidosis). If an increase in acid overwhelms the body's acid-base control systems, the blood will become acidic. As blood pH drops (becomes more acidic), the parts of the brain that regulate breathing are stimulated to produce faster and deeper breathing (respiratory compensation). Breathing faster and deeper increases the amount of carbon dioxide exhaled. The kidneys also try to compensate by excreting more acid in the urine. However, both mechanisms can be overwhelmed if the body continues to produce too much acid, leading to severe acidosis and eventually heart problems and coma. The acidity or alkalinity of any solution, including blood, is indicated on the pH scale. Metabolic acidosis develops when the amount of acid in the body is increased through ingestion of a substance that is, or can be broken down (metabolized) to, an acid—such as wood alcohol (methanol), antifreeze (ethylene glycol), or large doses of aspirin (acetylsalicylic acid). Metabolic acidosis can also occur as a result of abnormal metabolism. The body produces excess acid in the advanced stages of shock and in poorly controlled type 1 diabetes mellitus (diabetic ketoacidosis). Even the production of normal amounts of acid may lead to acidosis when the kidneys are not functioning normally and are therefore not able to excrete sufficient amounts of acid in the urine. Major Causes of Metabolic Acidosis Diabetic ketoacidosis (buildup of ketoacids) Drugs and substances such as acetazolamide, alcohols, and aspirin Lactic acidosis (buildup of lactic acid Continue reading >>

Response To Disturbances

Response To Disturbances

The body tries to minimize pH changes and responds to acid-base disturbances with body buffers, compensatory responses by the lungs and kidney (to metabolic and respiratory disturbances, respectively) and by the kidney correcting metabolic disturbances. Body buffers: There are intracellular and extracellular buffers for primary respiratory and metabolic acid-base disturbances. Intracellular buffers include hemoglobin in erythrocytes and phosphates in all cells. Extracellular buffers are carbonate (HCO3–) and non-carbonate (e.g. protein, bone) buffers. These immediately buffer the rise or fall in H+. Compensation: This involves responses by the respiratory tract and kidney to primary metabolic and respiratory acid-base disturbances, respectively. Compensation opposes the primary disturbance, although the laboratory changes in the compensatory response parallel those in the primary response. This concept is illustrated in the summary below. Respiratory compensation for a primary metabolic disturbance: Alterations in alveolar ventilation occurs in response to primary metabolic acid-base disturbances. This begins within minutes to hours of an acute primary metabolic disturbance. Note that complete compensation via this mechanism may take up to 24 hours. Renal compensation for a primary respiratory disturbance: Here, the kidney alters excretion of acid (which influences bases as well) in response to primary respiratory disturbances. This begins within hours of an acute respiratory disturbance, but take several days (3-5 days) to take full effect. Correction of acid-base changes: Correction of a primary respiratory acid-base abnormality usually requires medical or surgical intervention of the primary problem causing the acid-base disturbance, e.g. surgical relief of a colla Continue reading >>

5.5 Metabolic Acidosis - Compensation

5.5 Metabolic Acidosis - Compensation

Acid-Base Physiology 5.5.1 Hyperventilation Compensation for a metabolic acidosis is hyperventilation to decrease the arterial pCO2. This hyperventilation was first described by Kussmaul in patients with diabetic ketoacidosis in 1874. The metabolic acidosis is detected by both the peripheral and central chemoreceptors and the respiratory center is stimulated. The initial stimulation of the central chemoreceptors is due to small increases in brain ISF [H+]. The subsequent increase in ventilation causes a fall in arterial pCO2 which inhibits the ventilatory response. Maximal compensation takes 12 to 24 hours The chemoreceptor inhibition acts to limit and delay the full ventilatory response until bicarbonate shifts have stabilised across the blood brain barrier. The increase in ventilation usually starts within minutes and is usually well advanced at 2 hours of onset but maximal compensation may take 12 to 24 hours to develop. This is �maximal� compensation rather than �full� compensation as it does not return the extracellular pH to normal. In situations where a metabolic acidosis develops rapidly and is short-lived there is usually little time for much compensatory ventilatory response to occur. An example is the acute and sometimes severe lactic acidosis due to a prolonged generalised convulsion: this corrects due to rapid hepatic uptake and metabolism of the lactate following cessation of convulsive muscular activity, and hyperventilation due to the acidosis does not occur. The expected pCO2 at maximal compensation can be calculated from a simple formula The arterial pCO2 at maximal compensation has been measured in many patients with a metabolic acidosis. A consistent relationship between bicarbonate level and pCO2 has been found. It can be estimated from the Continue reading >>

Metabolic Acidosis

Metabolic Acidosis

Metabolic acidosis is a condition that occurs when the body produces excessive quantities of acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low (less than 7.35) due to increased production of hydrogen ions by the body or the inability of the body to form bicarbonate (HCO3−) in the kidney. Its causes are diverse, and its consequences can be serious, including coma and death. Together with respiratory acidosis, it is one of the two general causes of acidemia. Terminology : Acidosis refers to a process that causes a low pH in blood and tissues. Acidemia refers specifically to a low pH in the blood. In most cases, acidosis occurs first for reasons explained below. Free hydrogen ions then diffuse into the blood, lowering the pH. Arterial blood gas analysis detects acidemia (pH lower than 7.35). When acidemia is present, acidosis is presumed. Signs and symptoms[edit] Symptoms are not specific, and diagnosis can be difficult unless the patient presents with clear indications for arterial blood gas sampling. Symptoms may include chest pain, palpitations, headache, altered mental status such as severe anxiety due to hypoxia, decreased visual acuity, nausea, vomiting, abdominal pain, altered appetite and weight gain, muscle weakness, bone pain, and joint pain. Those in metabolic acidosis may exhibit deep, rapid breathing called Kussmaul respirations which is classically associated with diabetic ketoacidosis. Rapid deep breaths increase the amount of carbon dioxide exhaled, thus lowering the serum carbon dioxide levels, resulting in some degree of compensation. Overcompensation via respiratory alkalosis to form an alkalemia does not occur. Extreme acidemia leads to neurological and cardia Continue reading >>

How Does The Renal System Compensate For Conditions Of Respiratory Alkalosis?

How Does The Renal System Compensate For Conditions Of Respiratory Alkalosis?

In order to function normally, your body needs a blood pH of between 7.35 and 7.45. Alkalosis is when you have too much base in your blood, causing your blood pH to rise above 7.45. The lungs and the kidneys are the two main organs involved in maintaining a normal blood pH. The lungs do this by blowing off carbon dioxide, since most of the acid in the body is carbonic acid, which is made from carbon dioxide during metabolic processes. The amount of carbon dioxide removed is controlled by your breathing rate. The kidneys maintain blood pH by controlling the amount of bicarbonate, which is a base that is excreted from the body. The kidneys also control the amount of acids excreted from the body. Respiratory alkalosis occurs when the lungs are blowing off more carbon dioxide than the body is producing. This usually occurs from hyperventilation. Your body's immediate response, after about 10 minutes of respiratory alkalosis, is a process called cell buffering. During cell buffering, hydrogen ions found in hemoglobin, proteins and phosphates, move out of the cells and into the extracellular fluid. There they combine with bicarbonate molecules and form carbonic acid. This process helps to reduce the amount of bicarbonate in the body and increase the amount of acid. However, while cell buffering occurs quickly, it does not have a huge effect on the body's pH. After about two to six hours of respiratory alkalosis the kidneys respond. They begin to limit the excretion of hydrogen and other acids and increase the excretion of bicarbonate. It usually takes the kidneys two or three days to reach a new steady state. In chronic respiratory alkalosis, the pH may constantly be high, but the body learns to adapt to it over time, with the help of the kidneys. Continue reading >>

Acid-base Balance

Acid-base Balance

Your blood needs the right balance of acidic and basic (alkaline) compounds to function properly. This is called the acid-base balance. Your kidneys and lungs work to maintain the acid-base balance. Even slight variations from the normal range can have significant effects on your vital organs. Acid and alkaline levels are measured on a pH scale. An increase in acidity causes pH levels to fall. An increase in alkaline causes pH levels to rise. When the levels of acid in your blood are too high, it’s called acidosis. When your blood is too alkaline, it is called alkalosis. Respiratory acidosis and alkalosis are due to a problem with the lungs. Metabolic acidosis and alkalosis are due to a problem with the kidneys. Each of these conditions is caused by an underlying disease or disorder. Treatment depends on the cause. When you breathe, your lungs remove excess carbon dioxide from your body. When they cannot do so, your blood and other fluids become too acidic. Symptoms of respiratory acidosis Symptoms may include fatigue, shortness of breath, and confusion. Causes of respiratory acidosis There are several different causes of respiratory acidosis including: chest deformities or injuries chronic lung and airway diseases overuse of sedatives obesity Types of respiratory acidosis There are no noticeable symptoms of chronic respiratory acidosis. This is due to the fact that your blood slowly becomes acidic and your kidneys adjust to compensate, returning your blood to a normal pH balance. Acute respiratory acidosis comes on suddenly, leaving the kidneys no time to adjust. Those with chronic respiratory acidosis may experience acute respiratory acidosis due to another illness that causes the condition to worsen. Diagnosis of respiratory acidosis A complete physical examination Continue reading >>

Handling Ph: How Your Body Regulates Acidity

Handling Ph: How Your Body Regulates Acidity

When it comes to pH, your body likes to keep a tight control of the balance between acidity and alkalinity. The normal range for pH in your body is between 7.35-7.45 so, very slightly alkaline. At times, this balance can be disrupted. I will be talking about what occurs. Now, we must think about the ways you can control acidity. One is to remove/add acid, the other is to remove/add base. So how can we do this? There are two places where we can do this — the lungs and the kidneys. The lungs may seem like a strange place for controlling pH however, if we consider how CO2 is transported from the tissues (read more here), we see that CO2 dissociates into carbonic acid. Hence, the higher the CO2 levels in the tissues, the lower the pH gets (more acidic). So, if we are experiencing an Acidosis (low pH), if we decrease our CO2, we can increase the pH. We do this by hyperventilating and blowing off our CO2 however, this is limited by the amount of CO2 we have in our bodies; once we have blown off all our CO2, there is no more that the lungs can do to help us compensate. Conversely, if we experience an Alkylosis (high pH) our lungs can try to compensate by slowing down our breathing to increase our CO2 however, this can be dangerous because it can cause hypoxia (lack of oxygen). The benefit of respiratory compensation is that it happens very quickly (a few minutes) however, it has a very limited range of effectiveness. The kidneys deal in acids and bases, they can excrete/retain H+ if needed and they also control the excretion/retention of bicarbonate (HCO3-). If you are acidotic, your kidneys will try to excrete H+ and retain HCO3-, if you are alkylotic, your kidneys will try to retain H+ and excrete HCO3-. The drawback of this is that it takes a few days to be effective but, 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 >>

Free Nursing Flashcards About Acid-base/fluid-elec

Free Nursing Flashcards About Acid-base/fluid-elec

How does the body compensate for Respiratory Acidosis? Kidneys retain bicarb & release H+ to increase ph How does the body compensate for Respiratory Alkalosis? The kidneys retain H+ and excretee bicarb to decrease pH How does the body compensate for Metabolic Acidosis? Respiration increase to decrease the CO2 which lowers carbonic acid, which increases bicarb and pH How does the body compensate for Metabolic Alkalosis? Respirations decrease which increases CO2, causing carbonic acid to increase and pH to decrease What actions in the body causes Respiratory Acidosis? decreased respiration causes increase in CO2 and carbonic acid, which decreases bicarb and pH... What actions in the body causes Respiratory Alkalosis? Increased respiration causes a decrease in CO2 and carbonic acid, which increases bicarb and pH... What actions in the body causes Metabolic Acidosis? Decreased bicarb (from diarrhea, DKA or renal failure) causes increased carbonic acid and decreased pH... What actions in the body causes Metabolic Alkalosis? Increased bicarb (from prolonged vomiting, diuretics, antacids) causes a decrease in carbonic acid and increased pH... What is the normal range for HCO3 (bicarb)? What is the problem if the CO2 drops below 35? What is the problem if the CO2 rises above 45? What is the problem if the bicarb drops below 22? What is the problem if the bicarb rises above 26? What is the problem if the pH drops below 7.35? What is the problem if the pH rises above 7.45? Where is Na+ more concentrated...ECF or ICF? Where is K+ more concentrated...ECF or ICF? What is magnesium (Mg2+) responsible for? What is phosphorus (PO4) responsible for? What is bicarbonate (HCO3) responsible for? It a buffer to regulate acid-base balance Which area (blood volume or cellular level) does Is Continue reading >>

Acid-base Disorders Flashcards | Quizlet

Acid-base Disorders Flashcards | Quizlet

-accomplished by substances in blood buffering the pH (soaking up H+) *bicarbonate (5%, but most physiologically important) what are two ways to get acid out of the body? -pee it out through renal excretion as H+ *diabetic ketoacidosis, lactic acidosis (Increased AG) *diarrhea, renal failure (no change in AG( how does the body compensate for metabolic acidosis? *lungs compensate by increasing respiration (blowing off CO2) *kidneys compensate by excreting more H+ (minimal effect compared to the lungs) -the total concentration of positive molecules (Na+, K+) minus the total concentration of negative molecules (CL-, HCO3-) -many normal minor negative molecules are not counted, which collectively add up -many abnormal molecules have a negative charge (lactic acid, ketones), so there are more positive charges in the calculation and the anion gap increases how does the body compensate for respiratory alkalosis? -kidneys excrete HCO3- and decrease H+ excretion -compensatory abilities of the lung are 100 times greater than the kidney -compensation by both lungs and kidneys takes a while to kick in -in acute stages, you will see relatively large abnormalities of pH -as compensation occurs the pH will return closer to normal, but other values will be abnormal still until the underlying problem is fixed what condition does this describe: decreased pH and increased pCO2 what condition does this describe: decreased pH and decreased pCO2 what condition does this describe: increased pH and decreased pCO2 what condition does this describe: increased pH and increased pCO2 what happens to pH, pCO2 and pO2 at high altitude? -oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, methemoglobin -when there is acidosis, increased amounts of extracellular H+ diffuses into the cells and K+ ions c 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 >>

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