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What Is The Cause Of Respiratory Acidosis?

Ph Control: Respiratory Acidosis

Ph Control: Respiratory Acidosis

Normally, the kidneys and lungs maintain a pH between 7.35 - 7.45 in extracellular fluid. Respiratory acidosis occurs when the lungs cannot eliminate enough carbon dioxide from the body’s tissues. The typical reason is hypoventilation, or a low respiratory rate, causing the plasma pH to fall below 7.35 due to excessive carbon dioxide in the blood. When this occurs, certain chemoreceptors in the body are stimulated to increase the respiratory rate. The kidneys also help by secreting more hydrogen ions (acid) into the tubular fluid and generating more bicarbonate (base) to help stabilize the pH. Respiratory acidosis can cause many physiological problems, particularly in the nervous and cardiovascular systems which are sensitive to pH fluctuations. Continue reading >>

Respiratory Acidosis

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 >>

Respiratory Acidosis

Respiratory Acidosis

DEFINITION Respiratory acidosis = a primary acid-base disorder in which arterial pCO2 rises to an abnormally high level. PATHOPHYSIOLOGY arterial pCO2 is normally maintained at a level of about 40 mmHg by a balance between production of CO2 by the body and its removal by alveolar ventilation. PaCO2 is proportional to VCO2/VA VCO2 = CO2 production by the body VA = alveolar ventilation an increase in arterial pCO2 can occur by one of three possible mechanisms: presence of excess CO2 in the inspired gas decreased alveolar ventilation increased production of CO2 by the body CAUSES Inadequate Alveolar Ventilation central respiratory depression drug depression of respiratory centre (eg by opiates, sedatives, anaesthetics) neuromuscular disorders lung or chest wall defects airway obstruction inadequate mechanical ventilation Over-production of CO2 -> hypercatabolic disorders Malignant hyperthermia Thyroid storm Phaeochromocytoma Early sepsis Liver failure Increased Intake of Carbon Dioxide Rebreathing of CO2-containing expired gas Addition of CO2 to inspired gas Insufflation of CO2 into body cavity (eg for laparoscopic surgery) EFFECTS CO2 is lipid soluble -> depressing effects on intracellular metabolism RESP increased minute ventilation via both central and peripheral chemoreceptors CVS increased sympathetic tone peripheral vasodilation by direct effect on vessels acutely the acidosis will cause a right shift of the oxygen dissociation curve if the acidosis persists, a decrease in red cell 2,3 DPG occurs which shifts the curve back to the left CNS cerebral vasodilation increasing cerebral blood flow and intracranial pressure central depression at very high levels of pCO2 potent stimulation of ventilation this can result in dyspnoea, disorientation, acute confusion, headache, Continue reading >>

Respiratory Acidosis

Respiratory Acidosis

Respiratory acidosis can be defined as a medical condition in which hypoventilation or decreased ventilation leads to an increase in the concentration of blood carbon dioxide and decreased pH or acidosis. CO2 is constantly produced as the cells of the body respire. However, carbon dioxide can rapidly accumulate if the lungs are unable to expel it adequately through alveolar ventilation. Hence, alveolar hypoventilation leads to increased levels of PaCO2, a condition which is referred to as hypercapnia. Increased levels of PaCO2 reduce the HCO3/PaCO2 ratio as well as decrease the pH levels. The ICD-9 Code for this disorder is 276.2. The condition is subdivided into the following two types: In this form, the PaCO2 levels are elevated above 47 mm Hg or 6.3 kPa reference mark along with accompanying acidemia (pH levels less than 7.35). In this type, the PaCO2 levels are elevated above upper limit of reference range, with normal blood pH levels (between 7.35 and 7.45) or near normal pH that is secondary to the renal compensation and elevated levels of serum bicarbonate (HCO3 greater than 30 mm Hg). There are a number of factors which might be responsible for the development of this disorder. The causes responsible for both types of respiratory acidosis might differ from each other. These causes have been mentioned below: It occurs due to an abrupt or sudden failure of ventilation. This can occur due to the following factors: Exacerbation of chronic obstructive pulmonary disease or COPD Depression of central respiratory center caused by drugs or cerebral disease Airway obstruction caused by asthma, emphysema, bronchitis or pneumonia Inadequate ventilation caused by neuromuscular diseases, such as amyotrophic lateral sclerosis, myasthenia gravis, muscular dystrophy and Guillai Continue reading >>

Acid Base Statuses

Acid Base Statuses

A B Metabolic Acidosis (1) results from cold stress Respiratory Alkalosis (1) results from excessive CO2 blown off Body decr carbonic acid (1) results in slow respirations so that CO2 is retained Acidosis (1) symptoms (a) CNS depression (b) errors in judgment (c) disorientation (d) drowsiness (e) stupor (f) coma Hydrogen Ions excess (1) results in acidosis as pH falls below 7.35 (2) hydrogen ions are forced into the cells causing K+ to move into the cells Diabetic Ketoacidosis metabolic acidosis Metabolic Acidosis dehydration after an extended bout of diarrhea COPD respiratory acidosis Diarrhea (1) respirtory acidosis Anxiety (1)results in respiratory alkalosis (2) associated w/hyperventilation (2) during hyperventilation CO2 is blown off which lowers the amount of acid in the system Severe Asthma Respiratory Alkalosis Acute Renal Failure (1) metabolic acidosis (2) hypermagnesemia (3) hyperkalemia (4) hypocalcemia Diarrhea (1) metabolic acidosis (2) leads to meta acid because there is an over-elimination of bicarbonate Alkalosis (1) signs (a) tingling fingers, toes & face (b) estreme nervousness (c) twitching of muscles (d) tetany Severe Asthma respiratory acidosis Vomiting (1) metabolic alkalosis (2) leads to metabolic alkalosis as hydrochloric acid is lost from the stomach Aspirin metabolic acidosis Overdose of Morphine respiratory acisosis Vigorous Diuresis metabolic alkalosis End Stage Muscular Distrophy respiratory acidosis Severe Hypokalemia metabolic alkalosis Renal Failure (1) results in metabolic acisosis as fluid build up turns acidic Shock (1) metabolic acidosis (2) meta acid because acid is added to the system (3) anaerobic metabolic pathways result in lactate and hydrogen irons (forming lactic acid) Hyperventilation (1) respiratory alkalosis (2) leads to re 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 >>

Respiratory Acidosis

Respiratory Acidosis

Respiratory acidosis can arise from a break in any one of these links. For example, it can be caused from depression of the respiratory center through drugs or metabolic disease, or from limitations in chest wall expansion due to neuromuscular disorders or trauma (Table 90-1). It can also arise from pulmonary disease, card iog en ic pu lmon a ryedema, a spira tion of a foreign body or vomitus, pneumothorax and pleural space disease, or through mechanical hypoventilation. Unless there is a superimposed or secondary metabolic acidosis, the plasma anion gap will usually be normal in respiratory acidosis. Introduction Respiratory acidosis is characterized by an increased arterial blood PCO2 and H+ ion concentration. The major cause of respiratory acidosis is alveolar hypoventilation. The expected physiologic response is an increased PHCO3. The increase in concentration of bicarbonate ions (HCO3) in plasma (PHCO3) is tiny in patients with acute respiratory acidosis, but is much larger in patients with chronic respiratory acidosis. Respiratory alkalosis is caused by hyperventilation and is characterized by a low arterial blood PCO2 and H+ ion concentration. The expected physiologic response is a decrease in PHCO3. As in respiratory acidosis, this response is modest in patients with acute respiratory alkalosis and much larger in patients with chronic respiratory alkalosis. Although respiratory acid-base disorders are detected by measurement of PCO2 and pH in arterial blood and may reveal the presence of a serious underlying disease process that affected ventilation, it is important to recognize the effect of changes in capillary blood PCO2 in the different organs on the binding of H+ ions to intracellular proteins, which may change their charge, shape, and possibly their funct Continue reading >>

Respiratory Acidosis

Respiratory Acidosis

Causes of respiratory acidosis include: Diseases of the lung tissue (such as pulmonary fibrosis, which causes scarring and thickening of the lungs) Diseases of the chest (such as scoliosis) Diseases affecting the nerves and muscles that signal the lungs to inflate or deflate Drugs that suppress breathing (including powerful pain medicines, such as narcotics, and "downers," such as benzodiazepines), often when combined with alcohol Severe obesity, which restricts how much the lungs can expand Obstructive sleep apnea Chronic respiratory acidosis occurs over a long time. This leads to a stable situation, because the kidneys increase body chemicals, such as bicarbonate, that help restore the body's acid-base balance. Acute respiratory acidosis is a condition in which carbon dioxide builds up very quickly, before the kidneys can return the body to a state of balance. Some people with chronic respiratory acidosis get acute respiratory acidosis because an illness makes their condition worse. Continue reading >>

The Four Primary Disturbances Of Acid-base Balance

The Four Primary Disturbances Of Acid-base Balance

Primary Respiratory Acidosis initiating event: V�A (hypoventilation) chronic obstructive pulmonary disease (COPD) weak respiratory muscles (neuromuscular diseases) barbiturate poisoning (central nervous system depression) resultant effects: CO2 retention PaCO2, [H+] and pH compensations: 2� metabolic alkalosis HCO3- retention via PaCO2 effect on renal proximal tubules Primary Respiratory Alkalosis initiating event: V�A (hyperventilation) salicylate intoxication (over-aggressive aspirin therapy) hyperexcitability psychogenic paroxysmal hyperventilation ("brown paper bag" therapy) artificial ventilation resultant effects: CO2 elimination PaCO2, [H+] and pH compensations: 2� metabolic acidosis HCO3- retention via reverse PaCO2 effect on renal proximal tubules Primary Metabolic Acidosis initiating events: renal and extrarenal diabetes mellitus and ketoacidosis (larger than normal anion gap) severe shock or heart failure and lactic acidosis (larger than normal anion gap) diarrhea and loss of bicarbonate ions (normal anion gap) renal tubular acidosis and retention of hydrogen ions (normal anion gap) resultant effects: [H+] and/or [HCO3-], pH compensations: 2� respiratory alkalosis (with renal participation if possible) CO2 elimination via acid drive on ventilation Kussmaul respiration (characteristic deep labored breathing) Primary Metabolic Alkalosis initiating events: renal and extrarenal chronic potassium ion depletion (aggressive diuretic therapy, hyperaldosteronism) protracted vomiting (pyloric obstruction, gastric ulcers) and loss of gastric acids dehydration and depletion of extracellular fluid volume (contraction alkalosis) resultant effects: [H+] and/or [HCO3-], pH urine pH will be paradoxically low (acidic) if there is chronic depletion of potassium ions c Continue reading >>

Respiratory Acidosis

Respiratory Acidosis

LABORATORY TESTS The following lab tests can be used to interpret and explain acidosis and alkalosis conditions. All are measured on blood samples. 1. pH: This measures hydrogen ions - Normal pH = 7.35-7.45 2. pCO2= Partial Pressure of Carbon Dioxide: Although this is a pressure measurement, it relates to the concentration of GASEOUS CO2 in the blood. A high pCO2 may indicate acidosis. A low pCO2 may indicate alkalosis. 3. HCO3- = Bicarbonate: This measures the concentration of HCO3- ion only. High values may indicate alkalosis since bicarbonate is a base. Low values may indicate acidosis. 4. CO2 = Carbon Dioxide Content: This is a measure of ALL CO2 liberated on adding acid to blood plasma. This measure both carbon dioxide dissolved and bicarbonate ions and is an older test. Do not confuse with pCO2 Typically, dissolved carbon dioxide = l.2-2.0 mmoles/L and HCO3- = 22-28 mmoles/L Therefore, although it is listed as CO2 content, the lab test really reflects HCO3- concentration. Respiratory Acidosis .ABNORMAL pH IN THE BODY: ACIDOSIS AND ALKALOSIS: INTRODUCTION: Normal blood pH is maintained between 7.35 and 7.45 by the regulatory systems. The lungs regulate the amount of carbon dioxide in the blood and the kidneys regulate the bicarbonate. When the pH decreases to below 7.35 an acidosis condition is present. Acidosis means that the hydrogen ions are increased and that pH and bicarbonate ions are decreased. A greater number of hydrogen ions are present in the blood than can be absorbed by the buffer systems. Alkalosis results when the pH is above 7.45. This condition results when the buffer base (bicarbonate ions) is greater than normal and the concentration of hydrogen ions are decreased. Both acidosis and alkalosis can be of two different types: respiratory and metabol Continue reading >>

Respiratory Acidosis: Causes And Regulation

Respiratory Acidosis: Causes And Regulation

This lesson will discuss an important relationship between the kidneys and the lungs and how both of them play a role in respiratory acidosis. We'll also discuss some of the major causes of respiratory acidosis. Mutualistic Relationships A mutualistic relationship refers typically to a couple of different species of animals helping one another out. Take, for example, the birds that clean an alligator's teeth. The alligator gets a free dental exam, no insurance necessary, and the birds get a nice meal. It's really weird in a way that a bird and a reptile would rely on one another. They are just so different in terms of their size, function, and appearance, but their relationship is nonetheless very important. Well, the kidneys have a relationship with the lungs that is equally weird but important. I mean, the lungs are much bigger, look totally different, and don't seem to be related to the kidneys at all! But these two organ systems are in a very important mutualistic relationship, only one fourth of which can be discussed in this lesson. A Couple of Important Terms Before we get to everything, I want to clarify some terms. 'Acidemia' refers to an abnormally low pH of the blood. pH is inversely proportional to the concentration of H+ (hydrogen ions, aka protons). Hydrogen ions confer acidity upon a substance. So if we raise the concentration of hydrogen, we actually lower the pH. Acidemia is a result of acidosis. 'Acidosis' refers to a pathological state or process that leads to acidemia. We'll be using these terms later, so keep them in mind. To help remember that acid has a low pH, just think about the fact that gastric acid sits 'down' in your stomach. Therefore, something acidic moves 'down' the pH scale. Respiratory Acidosis Okay, with that out of the way for a bit Continue reading >>

Ph Of The Blood - 6 - Causes Of Abnormality - M J Bookallil

Ph Of The Blood - 6 - Causes Of Abnormality - M J Bookallil

A rise in concentration of any of these acids in the blood causes a fall in the pH of the blood. Loss of acid from the blood (e.g. into gastric juice) causes a rise in the pH. Only HCl and H2CO3 can be lost from the blood in appreciable quantities. The bases which can cause changes in blood pH are: Administration of base by mouth or parenterally may cause blood pH to rise if rate of excretion does not match rate of administration. Loss of alkaline fluid from bowel (diarrhoea, intestinal obstruction or intestinal fistulae), or urine (after acetoazolamide) will cause blood pH to fall. 6.3 CLINICAL CLASSIFICATION OF CAUSES OF CHANGES IN BLOOD pH Clinical states of pH disturbence (acid-base inbalance) can conveniently be divided into two groups, i.e. (a)respiratory and (b)metabolic or non-respiratory. The reasons for this division into respiratory and non-respiratory are that: i) the compensatory mechanisms ( Section 3.5.1 ) and treatments ( Section 7 ) of the two types are different.; ii) the recognition of non-respiratory disturbances is masked by compensatory alterations in PCO2 and the recognition of changes in pH caused by PCO2 changes are masked by renal compensation. 6.3.1 RESPIRATORY ACIDOSIS. This is synonymous with CO2 retention and is usually a sign of hypoventilation. Compensation is renal. There is renal loss HCl in the form of buffer or as NH4Cl. During recvovery chloride has to be supplied and retained. 6.3.1.2 Inhalational of CO2 This is another cause of respiratory acidosis, but it is only likely to occur under situations of re-breathing, e.g. under anaesthesia or during resuscitation with a Water's cannister circuit without the cannister, i.e. ward resuscitators or Type C anaesthetic systems. ( Mapleson, 1954 ). 6.3.1.3 Increased production of CO2. This v Continue reading >>

Free Nursing Flashcards About Acid Base Knowledge

Free Nursing Flashcards About Acid Base Knowledge

Choose the acid-base disorder pyloric stenosis with projectile vomiting commonly causes.A) Respiratory alkalosis B) Metabolic acidosis C) Metabolic alkalosis D) Respiratory acidosis Which of the following conditions may cause metabolic acidosis? Choose all that apply. A) Excessive intake of bicarbonate antacid B) Hyperthyroidism C) Loss of gastric acid D) Salicylate overdose E) Untreated diabetes mellitus Choose the acid-base imbalance that acute renal failure causes. A) Metabolic alkalosis B) Respiratory acidosis C) Metabolic acidosis D) Respiratory alkalosis Which of the following lab values may be seen in fully compensated respiratory acidosis? A) Dec PaCO2, dec HCO3-, normal pH B) Inc PaCO2, dec HCO3-, normal pH C) Inc PaCO2, normal HCO3-, de pH D) Inc PaCO2, inc HCO3-, normal pH What is the compensatory mechanism for metabolic acidosis? A) Increased rate and depth of respirations. B) Increased renal excretion of bicarbonate. C) Decreased rate and depth of respirations. D) Decreased renal excretion of bicarbonate. Choose the acid-base imbalance that pneumococcal pneumonia causes. A) Metabolic alkalosis B) Metabolic acidosis C) Respiratory acidosis D) Respiratory alkalosis Choose the acid-base disorder that COPD type B commonly causes. A) Metabolic alkalosis B) Metabolic acidosis C) Respiratory alkalosis D) Respiratory acidosis Choose the acid-base imbalance that severe lack of insulin causes. A) Respiratory acidosis B) Metabolic acidosis C) Respiratory alkalosis D) Metabolic alkalosis Which of the following lab values would be seen in a patient who has end-stage type B COPD (chronic bronchitis)? A) Inc PaCO2, dec HCO3-, dec pH. B) Decr PaCO2, decr HCO3-, incr pH. C) Decr PaCO2, incr HCO3-, decr pH. D) Incr PaCO2, incr HCO3-, decr pH. Choose the acid-base imbalance Continue reading >>

What Is Respiratory Acidosis? Signs, Symptoms, Causes And Treatment

What Is Respiratory Acidosis? Signs, Symptoms, Causes And Treatment

Respiratory acidosis is a serious condition which occurs when your lungs is unable to remove enough carbon dioxide. Carbon dioxide is produced continuously as your cells respire. If the lungs cannot remove enough carbon dioxide via alveolar ventilation, it will accumulate quickly in the body. Too much carbon dioxide in the body reduces the pH of the blood and other fluids. This causes the blood and bodily fluids to become too acidic, a condition which is commonly referred to as acidosis. Normal pH level of the blood should be between 7.35 and 7.45. If your blood pH goes under 7.35, you have acidosis. Normally, your lungs and kidneys work together to balance the bloods pH. When your blood pH falls to an acidic level, your brain will signal your body to breathe faster and deeper, so as to exhale more carbon dioxide. However, if the body keeps producing excess acid, this process can lead to severe respiratory acidosis. If left untreated, severe respiratory acidosis can lead to respiratory failure, heart problems, or coma. There are 2 main forms of respiratory acidosis: acute respiratory acidosis and chronic respiratory acidosis. Acute respiratory acidosis usually occurs fast and requires emergency treatment. If this condition is left untreated, it can get worse leading to fatal consequences. On the other hand, chronic respiratory acidosis usually takes time to develop. Instead, the kidney produces more bicarbonate, so as to maintain a normal pH. Signs and symptoms of chronic respiratory acidosis may not be as noticeable at first. Acute respiratory acidosis will produce the following signs and symptoms: The signs and symptoms of chronic acidosis may be overlooked due to a long-term illness. These would include: The lungs are responsible for removing carbon dioxide when you Continue reading >>

Causes Of Respiratory Acidosis And Alkalosis - Deranged Physiology

Causes Of Respiratory Acidosis And Alkalosis - Deranged Physiology

Causes of Respiratory Acidosis and Alkalosis Respiratory acidosis and alkalosis are featured in virtually every paper, and being able to identify a respiratory acid-base disturbance is a vital skill for the CICM fellowship candidate. The SAQs will frequently require the application of the usual rules of compensation to reveal a hidden acid-base disorder, eg. "this patient has a low CO2 but it is not low enough". Questions which involve respiratory acid-base disturbances are too numerous to list. Some representative examples include the following: Question 12.3 from the second paper of 2014 Question 3.4 from the first paper of 2013 Question 3.5 from the first paper of 2013 Question 8.3 from the first paper of 2012 Question 9.1 from the first paper of 2011 Question 7.2 from the first paper of 2009 Several CICM fellowship questions revolve around the core question, "what possible causes for this respiratory acid-base disturbance can you think of ?" The causes can be split into aetiological categories, as below: Causes of Respiratory Acidosis and Alkalosis Rebreathing of CO2-containing expired gas Insufflation of CO2 into body cavity (eg for laparoscopic surgery) CO2 increases by 3mmg for every minute of apnoea central respiratory depression eg. by drugs or post-ictally neuromuscular disorders resulting in weakness lung or chest wall defects resulting in restriction The pH change in response to a chronic respiratory acid-base disturbance 0: An acute change in PaCO2 will not change the Standard Base Excess. 4: In chronic disorders, the expected change in SBE will be 0.4 times the change in PaCO2 ... i.e. expected SBE = 0.4 (40 - PaCO2) 1: In compensation for metabolic acidosis, the compensatory change in PaCO2 will be proportional to the SBE. ..i.e. expected CO2 = 40 + (1.0 Continue reading >>

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