Describe How The Kidneys Respond To Respiratory Acidosis

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 >>

Shared Flashcard Set

Details Title Acid Base Balance Description Acid Base Balance Total Cards 214 Subject Nursing Level Undergraduate 2 Created 10/14/2012 Click here to study/print these flashcards. Create your own flash cards! Sign up here. Additional Nursing Flashcards Cards Term An opioid drug overdose would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Pulmonary Edema would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Chest trauma would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Neuromuscular disease would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term COPD would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Airway obstruction would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Pneumonia would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term TB would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Emphysema would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Asthma would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Cigarrette smoking would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term Pleural effusion would put a patient at most risk for what acid/base imbalance? Definition Respiratory Acidosis Term What is pleural effusion? Definition excess fluid that accumulates in the pleura, the fluid-filled space that surrounds the lungs Pleural effusion is excess fluid that accu Continue reading >>

How The Kidneys Regulate Acid Base Balance

Acid-Base Balance Everyday processes like walking, the digestion of food, and the overall metabolism in your body produce a lot of acid as a byproduct. Because of this, you'd be a giant walking lemon if it wasn't for your kidneys. What I mean is, like a lemon, you'd be filled with acid if your kidneys weren't there to help you regulate your body's pH through something we call acid-base balance. This is a process whereby receptors are able to determine the pH of your body and blood and do something about it if it's too acidic or too basic. If an imbalance in the pH is detected by your lungs, buffers, or kidneys, your body springs into action to take care of the problem. In this lesson, we'll focus in on how the kidneys help to control the acid-base balance in your body. Protons and Buffers Whereas the buffers in your body and your lungs are involved in the rapid adjustment of your blood's pH, the kidneys adjust the pH more slowly. Under normal conditions, the kidney's main role in acid-base balance is through the excretion of acid in the form of hydrogen (H+) ions. The kidneys secrete excess hydrogen ions primarily in the proximal tubule. The interesting thing to note is that while the proximal tubule secretes a lot of acid, the tubular fluid's pH remains virtually unchanged. This is because buffers filtered by the glomerulus, including phosphate and bicarbonate, help to minimize the acidity of the tubular fluid. In fact, what's really cool is that the pH of the tubular fluid, by the time it reaches the collecting duct, is about 7.4, which is exactly the pH of normal blood. The Collecting Duct However, by the time urine is excreted out of the body, it can be acidic, basic, or neutral. This is because the end-all, be-all gatekeeper in determining the final pH of urine is Continue reading >>

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 >>

Renal Response To Acid-base Imbalance

The kidneys respond to acid-base disturbances by modulating both renal acid excretion and renal bicarbonate excretion. These processes are coordinated to return the extracellular fluid pH, and thus blood pH, to normal following a derangement. Below we discuss the coordinated renal response to such acid-base disturbances. Acidosis refers to an excess extracellular fluid H+ concentration and thus abnormally low pH. The overall renal response to acidosis involves the net urinary excretion of hydrogen, resorption of nearly all filtered bicarbonate, and the generation of novel bicarbonate which is added to the extracellular fluid. Processes of renal acid excretion result in both direct secretion of free hydrogen ions, thus acidifying the urine, as well as secretion of hydrogen in the form of ammonium. These mechanisms are molecularly coupled to the generation of fresh bicarbonate, which is added to the extracellular fluid. Additionally, as discussed in renal bicarbonate excretion, nearly all filtered bicarbonate is resorbed and thus its urinary loss is minimized. Together, these processes slowly reduce ECF hydrogen ions and increase ECF bicarbonate concentrations, thus gradually raising blood pH to its normal value. Alkalosis refers to a insufficient extracellular fluid H+ concentration and thus abnormally high pH. The overall response to alkalosis involves reduced urinary secretion of hydrogen and the urinary excretion of filtered bicarbonate. Renal acid excretion is minimized in the context of alkalosis, thus preventing further increases in the ECF pH. Instead, renal bicarbonate excretion is increased, resulting in loss of bicarbonate from the extracellular fluid, and an alkalinization of the urine. Together these processes reduce ECF bicarbonate concentrations and in doin Continue reading >>

Fluid/electrolyte Balance

Content Body Fluids Compartments Composition of Body Fluids Electrolyte Composition of Body Fluids Extracellular and Intracellular Fluids Fluid Movement Among Compartments Fluid Shifts Regulation of Fluids And Electrolytes Water Balance and ECF Osmolality Water Output Regulation of Water Intake Regulation of Water Output Primary Regulatory Hormones Disorders of Water Balance Electrolyte Balance Sodium in Fluid and Electrolyte Balance Sodium balance Regulation of Sodium Balance: Aldosterone Atrial Natriuretic Hormone (ANH) Potassium Balance Regulation of Potassium Balance Regulation of Calcium Regulation of Anions Acid-Base Balance Sources of Hydrogen Ions Hydrogen Ion Regulation Chemical Buffer Systems -- 1. Bicarbonate Buffer System - -2. Phosphate Buffer System -- 3. Protein Buffer System Physiological Buffer Systems Renal Mechanisms of Acid-Base Balance Reabsorption of Bicarbonate Generating New Bicarbonate Ions Hydrogen Ion Excretion Ammonium Ion Excretion Bicarbonate Ion Secretion Respiratory Acidosis and Alkalosis Respiratory Acid-Base Regulation Metabolic pH Imbalance Respiratory/Renal Compensation/Metabolic Acidosis Metabolic Alkalosis Fluid Balance- The amount of water gained each day equals the amount lost Electrolyte Balance - The ions gained each day equals the ions lost Acid-Base Balance - Hydrogen ion (H+) gain is offset by their loss Body Fluids Compartments Intracellular Fluid (ICF) - fluid found in the cells (cytoplasm, nucleoplasm) comprises 60% of all body fluids. Extracellular Fluid (ECF) - all fluids found outside the cells, comprises 40% of all body fluids Interstitial Fluid - 80% of ECF is found in localized areas: lymph, cerebrospinal fluid, synovial fluid, aqueous humor and vitreous body of eyes, between serous and visceral membranes, glomerular Continue reading >>

Acidosis

The kidneys and lungs maintain the balance (proper pH level) of chemicals called acids and bases in the body. Acidosis occurs when acid builds up or when bicarbonate (a base) is lost. Acidosis is classified as either respiratory or metabolic acidosis. Respiratory acidosis develops when there is too much carbon dioxide (an acid) in the body. This type of acidosis is usually caused when the body is unable to remove enough carbon dioxide through breathing. Other names for respiratory acidosis are hypercapnic acidosis and carbon dioxide acidosis. Causes of respiratory acidosis include: Chest deformities, such as kyphosis Chest injuries Chest muscle weakness Chronic lung disease Overuse of sedative drugs Metabolic acidosis develops when too much acid is produced in the body. It can also occur when the kidneys cannot remove enough acid from the body. There are several types of metabolic acidosis: Diabetic acidosis (also called diabetic ketoacidosis and DKA) develops when substances called ketone bodies (which are acidic) build up during uncontrolled diabetes. Hyperchloremic acidosis is caused by the loss of too much sodium bicarbonate from the body, which can happen with severe diarrhea. Poisoning by aspirin, ethylene glycol (found in antifreeze), or methanol Lactic acidosis is a buildup of lactic acid. Lactic acid is mainly produced in muscle cells and red blood cells. It forms when the body breaks down carbohydrates to use for energy when oxygen levels are low. This can be caused by: Cancer Drinking too much alcohol Exercising vigorously for a very long time Liver failure Low blood sugar (hypoglycemia) Medications, such as salicylates MELAS (a very rare genetic mitochondrial disorder that affects energy production) Prolonged lack of oxygen from shock, heart failure, or seve Continue reading >>

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 Homeostasis

Abstract Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3− and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3− is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys. Basic Concepts Intracellular and extracellular buffers are the most immediate mechanism of defense against changes in systemic pH. Bone and proteins constitute a substantial proportion of these buffers. However, the most important buffer system is the HCO3−/CO2 buffer system. The Henderson–Hasselbach equation (Equation 1) describes the relationship of pH, bicarbonate (HCO3−), and PCO2:where HCO3− is in milliequivalents per liter and PCO2 is in millimeters of mercury. Equation 2 represents the reaction (water [H2O] Continue reading >>

How Does Diabetes Disrupt Homeostasis?

4.5 Respiratory Acidosis - Compensation

Acid-Base Physiology 4.5.1 The compensatory response is a rise in the bicarbonate level This rise has an immediate component (due to a resetting of the physicochemical equilibrium point) which raises the bicarbonate slightly. Next is a slower component where a further rise in plasma bicarbonate due to enhanced renal retention of bicarbonate. The additional effect on plasma bicarbonate of the renal retention is what converts an "acute" respiratory acidsosis into a "chronic" respiratory acidosis. As can be seen by inspection of the Henderson-Hasselbalch equation (below), an increased [HCO3-] will counteract the effect (on the pH) of an increased pCO2 because it returns the value of the [HCO3]/0.03 pCO2 ratio towards normal. pH = pKa + log([HCO3]/0.03 pCO2) 4.5.2 Buffering in Acute Respiratory Acidosis The compensatory response to an acute respiratory acidosis is limited to buffering. By the law of mass action, the increased arterial pCO2 causes a shift to the right in the following reaction: CO2 + H2O <-> H2CO3 <-> H+ + HCO3- In the blood, this reaction occurs rapidly inside red blood cells because of the presence of carbonic anhydrase. The hydrogen ion produced is buffered by intracellular proteins and by phosphates. Consequently, in the red cell, the buffering is mostly by haemoglobin. This buffering by removal of hydrogen ion, pulls the reaction to the right resulting in an increased bicarbonate production. The bicarbonate exchanges for chloride ion across the erythrocyte membrane and the plasma bicarbonate level rises. In an acute acidosis, there is insufficient time for the kidneys to respond to the increased arterial pCO2 so this is the only cause of the increased plasma bicarbonate in this early phase. The increase in bicarbonate only partially returns the extracel Continue reading >>

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 >>

Respiratory Acidosis

Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood's pH (a condition generally called acidosis). Carbon dioxide is produced continuously as the body's cells respire, and this CO2 will accumulate rapidly if the lungs do not adequately expel it through alveolar ventilation. Alveolar hypoventilation thus leads to an increased PaCO2 (a condition called hypercapnia). The increase in PaCO2 in turn decreases the HCO3−/PaCO2 ratio and decreases pH. Terminology[edit] Acidosis refers to disorders that lower cell/tissue pH to < 7.35. Acidemia refers to an arterial pH < 7.36.[1] Types of respiratory acidosis[edit] Respiratory acidosis can be acute or chronic. In acute respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range (over 6.3 kPa or 45 mm Hg) with an accompanying acidemia (pH <7.36). In chronic respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range, with a normal blood pH (7.35 to 7.45) or near-normal pH secondary to renal compensation and an elevated serum bicarbonate (HCO3− >30 mm Hg). Causes[edit] Acute[edit] Acute respiratory acidosis occurs when an abrupt failure of ventilation occurs. This failure in ventilation may be caused by depression of the central respiratory center by cerebral disease or drugs, inability to ventilate adequately due to neuromuscular disease (e.g., myasthenia gravis, amyotrophic lateral sclerosis, Guillain–Barré syndrome, muscular dystrophy), or airway obstruction related to asthma or chronic obstructive pulmonary disease (COPD) exacerbation. Chronic[edit] Chronic respiratory acidosis may be secondary to many disorders, including COPD. Hypoventilation Continue reading >>

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 >>

Egan's Ch. 13

what is the state called in which arterial blood is more acidic than normal? aka increased concentration of hydrogen ions. Flashcards Matching Hangman Crossword Type In Quiz Test StudyStack Study Table Bug Match Hungry Bug Unscramble Chopped Targets Acid-Base Balance Question Answer what is the state called in which arterial blood is more acidic than normal? aka increased concentration of hydrogen ions. acidemia what is the difference called between the normal buffer base and the actual buffer base in a whole blood sample? base excess (BE) what is alkalemia? decreased hydrogen ion concentration in the blood; blood pH greater than 7.45 how is BE expressed? mEq/L what is the normal BE? +2 mEq/L what is the buffer base? the total blood buffer capable of binding hydrogen ions what is the normal blood buffer base (NBB) range? 48-52 mEq/L what is a titrable, nonvolitile acid called? fixed acid what does a fixed acid represent? the by-product of protein catabolism what kind of acids are phosphoric acid and sulfuric acid? fixed what is the Henderson-Hasselbalch (H-H) equation? the specific equation for calculating the pH of the bicarbonate buffer system of the blood what does pH = 6.1 + log HCO3-/(PaCO2 x 0.03) represent? H-H equation what is the importance of the H-H equation? it equals the pH of blood plasma, and since all buffer systems in the blood are in equilibrium, the pH of one system equals the pH of the entire plasma solution. what is hypercapnia? excess amounts of CO2 in the blood (PaCO2) what is the presence of lower than normal amounts of CO2 in the blood (PaCO2)? hypocapnia define metabolic acidosis? non-respiratory processes resulting in acidemia what is called when non-respiratory processes, such as losing fixed acid or gaining HCO3-, result in alkalemia? metabo Continue reading >>

Renal Physiology Acid-base Balance

Sort Your patient's blood pH is too low (acidosis), caused by metabolic acidosis. After examining the patient, you find that the urine bicarbonate levels are too low (H+ is being reabsorbed) and blood carbon dioxide levels are too high (too much blood acid); What does this mean? Based on the patient's pCO2 levels are they compensating or not? This means that the original problem of a low bicarbonate level needs to be compensated for by the lungs, which need to hyperventilate, expelling more CO2 (an acid). Since this patient's pCO2 levels are also high (not expelling enough acid), they are NOT compensating. Patient's blood pH is too high (alkalosis). This can be caused by either respiratory or metabolic alkalosis. Let's say it is metabolic alkalosis. What do you need to check to see if patient is compensating? If bicarbonate levels are high (too much base) and blood CO2 levels are high (too much acid), what do the lungs need to do to compensate? What does the patient's elevated Pco2 levels tell you? Patients partial pressure of Carbon dioxide and bicarbonate Take shallower breaths to prevent loss of acid Patient is compensating Patient's blood pH is too high (alkalosis). This can be caused by either respiratory or metabolic alkalosis. Let's say it is metabolic alkalosis. What do you need to check to see if patient is compensating? If bicarbonate levels are high (too much base) and blood CO2 levels are low (too little acid), what do the lungs need to do to compensate? Since the patient's pCO2 level is low, this tells you what? Patients pCO2 and bicarbonate Take shallower breaths to prevent loss of acid Not compensating Continue reading >>