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How Does Lactic Acidosis Happen?

Lactic Acidosis: Background, Etiology, Epidemiology

Lactic Acidosis: Background, Etiology, Epidemiology

Author: Kyle J Gunnerson, MD; Chief Editor: Michael R Pinsky, MD, CM, Dr(HC), FCCP, MCCM more... In basic terms, lactic acid is the normal endpoint of the anaerobic breakdown of glucose in the tissues. The lactate exits the cells and is transported to the liver, where it is oxidized back to pyruvate and ultimately converted to glucose via the Cori cycle. In the setting of decreased tissue oxygenation, lactic acid is produced as the anaerobic cycle is utilized for energy production. With a persistent oxygen debt and overwhelming of the body's buffering abilities (whether from chronic dysfunction or excessive production), lactic acidosis ensues. [ 1 , 2 ] (See Etiology.) Lactic acid exists in 2 optical isomeric forms, L-lactate and D-lactate. L-lactate is the most commonly measured level, as it is the only form produced in human metabolism. Its excess represents increased anaerobic metabolism due to tissue hypoperfusion. (See Workup.) D-lactate is a byproduct of bacterial metabolism and may accumulate in patients with short-gut syndrome or in those with a history of gastric bypass or small-bowel resection. [ 3 ] By the turn of the 20th century, many physicians recognized that patients who are critically ill could exhibit metabolic acidosis unaccompanied by elevation of ketones or other measurable anions. In 1925, Clausen identified the accumulation of lactic acid in blood as a cause of acid-base disorder. Several decades later, Huckabee's seminal work firmly established that lactic acidosis frequently accompanies severe illnesses and that tissue hypoperfusion underlies the pathogenesis. In their classic 1976 monograph, Cohen and Woods classified the causes of lactic acidosis according to the presence or absence of adequate tissue oxygenation. (See Presentationand Differe Continue reading >>

Lactic Acidosis

Lactic Acidosis

Fast facts Lactic acidosis is a build-up of lactic acid in your blood. It can be the result of intense exercise, severe dehydration, an underlying medical condition, or as a reaction to some substances and medications. Symptoms of lactic acidosis can initially include weakness and nausea. More severe symptoms, such as chest pain, a fast heartbeat or breathing difficulties, require immediate medical attention. You can reduce your risk of lactic acidosis by not abusing alcohol and by properly managing diabetes if you have it. What is lactic acidosis? Lactic acidosis is a build-up of lactic acid in your blood. It makes the blood too acidic. Inside the cells of your body, there are structures called mitochondria. Their role is to supply energy to the cells. Mitochondria break down glucose for energy using oxygen, a process known as aerobic respiration. In situations when your body is starved for oxygen, or needs a lot of energy very quickly (such as during intense exercise), your mitochondria can switch to an alternative process known as anaerobic respiration. It is much less efficient, but it does not require oxygen and can, for a brief period, produce energy more quickly. Anaerobic respiration produces lactic acid (also known as lactate), making the blood more acidic. In most cases this is not a problem, because your liver and kidneys handle the excess lactic acid once your body starts to recover from oxygen starvation and returns to normal. However, when your body produces lactic acid faster than it can be removed, lactic acid builds up in your blood. Causes and risk factors Causes and risk factors of lactic acidosis include: Intense exercise; Low blood sugar, and; Some substances and medications - such as alcohol, cocaine, epinephrine, isoniazid, salicylates, and the di Continue reading >>

Etiology And Therapeutic Approach To Elevated Lactate

Etiology And Therapeutic Approach To Elevated Lactate

Etiology and therapeutic approach to elevated lactate aResearch Center for Emergency Medicine, Aarhus University Hospital, Denmark bDepartment of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States cDepartment of Medicine, Division of Pulmonary Critical Care Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States bDepartment of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States dDepartment of Anesthesia Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, United States bDepartment of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States cDepartment of Medicine, Division of Pulmonary Critical Care Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States aResearch Center for Emergency Medicine, Aarhus University Hospital, Denmark bDepartment of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States cDepartment of Medicine, Division of Pulmonary Critical Care Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States dDepartment of Anesthesia Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, United States Corresponding author: Michael W. Donnino Beth Israel Deaconess Medical Center One Deaconess Road, W/CC 2 Boston, Boston, MA 02215 Phone: 617-754-2450 Fax: 617-754-2350 [email protected] The publisher's final edited version of this article is available at Mayo Clin Proc See other articles in PMC that cite the published article. Lactate levels are commonly evaluated in acutely ill patients. Although most commonly used in the context of evaluating shock, lactate can be elevated for many reasons. While tissue hypoperfusion is probably the most common cause of elevation Continue reading >>

Lactic Acidosis

Lactic Acidosis

Lactic acidosis is a medical condition characterized by the buildup of lactate (especially L-lactate) in the body, which results in an excessively low pH in the bloodstream. It is a form of metabolic acidosis, in which excessive acid accumulates due to a problem with the body's metabolism of lactic acid. Lactic acidosis is typically the result of an underlying acute or chronic medical condition, medication, or poisoning. The symptoms are generally attributable to these underlying causes, but may include nausea, vomiting, rapid deep breathing, and generalised weakness. The diagnosis is made on biochemical analysis of blood (often initially on arterial blood gas samples), and once confirmed, generally prompts an investigation to establish the underlying cause to treat the acidosis. In some situations, hemofiltration (purification of the blood) is temporarily required. In rare chronic forms of lactic acidosis caused by mitochondrial disease, a specific diet or dichloroacetate may be used. The prognosis of lactic acidosis depends largely on the underlying cause; in some situations (such as severe infections), it indicates an increased risk of death. Classification[edit] The Cohen-Woods classification categorizes causes of lactic acidosis as:[1] Type A: Decreased tissue oxygenation (e.g., from decreased blood flow) Type B B1: Underlying diseases (sometimes causing type A) B2: Medication or intoxication B3: Inborn error of metabolism Signs and symptoms[edit] Lactic acidosis is commonly found in people who are unwell, such as those with severe heart and/or lung disease, a severe infection with sepsis, the systemic inflammatory response syndrome due to another cause, severe physical trauma, or severe depletion of body fluids.[2] Symptoms in humans include all those of typical m Continue reading >>

Lactic Acidosis And Exercise: What You Need To Know

Lactic Acidosis And Exercise: What You Need To Know

Muscle ache, burning, rapid breathing, nausea, stomach pain: If you've experienced the unpleasant feeling of lactic acidosis, you likely remember it. It's temporary. It happens when too much acid builds up in your bloodstream. The most common reason it happens is intense exercise. Symptoms The symptoms may include a burning feeling in your muscles, cramps, nausea, weakness, and feeling exhausted. It's your body's way to tell you to stop what you're doing The symptoms happen in the moment. The soreness you sometimes feel in your muscles a day or two after an intense workout isn't from lactic acidosis. It's your muscles recovering from the workout you gave them. Intense Exercise. When you exercise, your body uses oxygen to break down glucose for energy. During intense exercise, there may not be enough oxygen available to complete the process, so a substance called lactate is made. Your body can convert this lactate to energy without using oxygen. But this lactate or lactic acid can build up in your bloodstream faster than you can burn it off. The point when lactic acid starts to build up is called the "lactate threshold." Some medical conditions can also bring on lactic acidosis, including: Vitamin B deficiency Shock Some drugs, including metformin, a drug used to treat diabetes, and all nucleoside reverse transcriptase inhibitor (NRTI) drugs used to treat HIV/AIDS can cause lactic acidosis. If you are on any of these medications and have any symptoms of lactic acidosis, get medical help immediately. Preventing Lactic Acidosis Begin any exercise routine gradually. Pace yourself. Don't go from being a couch potato to trying to run a marathon in a week. Start with an aerobic exercise like running or fast walking. You can build up your pace and distance slowly. Increase the Continue reading >>

Lactic Acidosis: Symptoms, Causes, And Treatment

Lactic Acidosis: Symptoms, Causes, And Treatment

Lactic acidosis occurs when the body produces too much lactic acid and cannot metabolize it quickly enough. The condition can be a medical emergency. The onset of lactic acidosis might be rapid and occur within minutes or hours, or gradual, happening over a period of days. The best way to treat lactic acidosis is to find out what has caused it. Untreated lactic acidosis can result in severe and life-threatening complications. In some instances, these can escalate rapidly. It is not necessarily a medical emergency when caused by over-exercising. The prognosis for lactic acidosis will depend on its underlying cause. A blood test is used to diagnose the condition. Lactic acidosis symptoms that may indicate a medical emergency include a rapid heart rate and disorientaiton. Typically, symptoms of lactic acidosis do not stand out as distinct on their own but can be indicative of a variety of health issues. However, some symptoms known to occur in lactic acidosis indicate a medical emergency. Lactic acidosis can occur in people whose kidneys are unable to get rid of excess acid. Even when not related to just a kidney condition, some people's bodies make too much lactic acid and are unable to balance it out. Diabetes increases the risk of developing lactic acidosis. Lactic acidosis may develop in people with type 1 and 2 diabetes mellitus , especially if their diabetes is not well controlled. There have been reports of lactic acidosis in people who take metformin, which is a standard non-insulin medication for treating type 2 diabetes mellitus. However, the incidence is low, with equal to or less than 10 cases per 100,000 patient-years of using the drug, according to a 2014 report in the journal Metabolism. The incidence of lactic acidosis is higher in people with diabetes who Continue reading >>

Glyburide And Metformin (oral Route)

Glyburide And Metformin (oral Route)

Precautions Drug information provided by: Micromedex It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects. Under certain conditions, too much metformin can cause lactic acidosis. The symptoms of lactic acidosis are severe and quick to appear. They usually occur when other health problems not related to the medicine are present and very severe, such as a heart attack or kidney failure. The symptoms of lactic acidosis include abdominal or stomach discomfort; decreased appetite; diarrhea; fast, shallow breathing; a general feeling of discomfort; muscle pain or cramping; and unusual sleepiness, tiredness, or weakness. If you have any symptoms of lactic acidosis, get emergency medical help right away. It is very important to carefully follow any instructions from your health care team about: Alcohol—Drinking alcohol may cause severe low blood sugar. Discuss this with your health care team. Other medicines—Do not take other medicines unless they have been discussed with your doctor. This especially includes nonprescription medicines such as aspirin, and medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems. Counseling—Other family members need to learn how to prevent side effects or help with side effects if they occur. Also, patients with diabetes may need special counseling about diabetes medicine dosing changes that might occur because of lifestyle changes, such as changes in exercise and diet. Furthermore, counseling on contraception and pregnancy may be needed because of the problems that can occur in patients with diabetes during pregnancy. Travel—Keep your recent prescription and your medical history with yo Continue reading >>

Lactic Acidosis

Lactic Acidosis

Background In basic terms, lactic acid is the normal endpoint of the anaerobic breakdown of glucose in the tissues. The lactate exits the cells and is transported to the liver, where it is oxidized back to pyruvate and ultimately converted to glucose via the Cori cycle. In the setting of decreased tissue oxygenation, lactic acid is produced as the anaerobic cycle is utilized for energy production. With a persistent oxygen debt and overwhelming of the body's buffering abilities (whether from chronic dysfunction or excessive production), lactic acidosis ensues. [1, 2] (See Etiology.) Lactic acid exists in 2 optical isomeric forms, L-lactate and D-lactate. L-lactate is the most commonly measured level, as it is the only form produced in human metabolism. Its excess represents increased anaerobic metabolism due to tissue hypoperfusion. (See Workup.) D-lactate is a byproduct of bacterial metabolism and may accumulate in patients with short-gut syndrome or in those with a history of gastric bypass or small-bowel resection. [3] By the turn of the 20th century, many physicians recognized that patients who are critically ill could exhibit metabolic acidosis unaccompanied by elevation of ketones or other measurable anions. In 1925, Clausen identified the accumulation of lactic acid in blood as a cause of acid-base disorder. Several decades later, Huckabee's seminal work firmly established that lactic acidosis frequently accompanies severe illnesses and that tissue hypoperfusion underlies the pathogenesis. In their classic 1976 monograph, Cohen and Woods classified the causes of lactic acidosis according to the presence or absence of adequate tissue oxygenation. (See Presentation and Differentials.) The causes of lactic acidosis are listed in the chart below. Go to Acute Lactic Ac Continue reading >>

Hiv And Lactic Acidosis

Hiv And Lactic Acidosis

What is lactic acidosis? Lactic acidosis is a condition caused by the buildup of lactic acid in the blood. The condition is a rare but serious side effect of some HIV medicines. HIV medicines in the nucleoside reverse transcriptase inhibitor (NRTI) drug class can cause the body to produce too much lactic acid. NRTIs can also damage the liver so that it can’t break down a molecule called lactate, leading to a buildup of lactic acid in the blood. If you are taking NRTIs, it’s important to know about lactic acidosis. Although lactic acidosis is a rare side effect of NRTIs, the condition can be life-threatening. Are there other risk factors for lactic acidosis? In addition to use of some HIV medicines, risk factors for lactic acidosis include the following: What are the symptoms of lactic acidosis? Lactic acidosis often develops gradually. Early signs of lactic acidosis can include fatigue, nausea and vomiting, stomach pain, and weight loss. These symptoms may not seem serious, but they can be the first signs of life-threatening lactic acidosis. If you are taking HIV medicines, always tell your health care provider about any symptoms that you are having—even symptoms that may not seem serious. Lactic acidosis can advance rapidly. Signs of dangerously high levels of lactate in the blood include: Above-normal heart rate Rapid breathing Jaundice (yellowing of the skin and the whites of the eyes) Muscle weakness If you are taking HIV medicines and have any of these symptoms, get medical help immediately. What tests are used to detect lactic acidosis? Tests used to diagnose lactic acidosis include: A test to measure the level of lactate in the blood Other blood tests to check the functioning of the liver What is the treatment for lactic acidosis? An HIV medicine that is ca Continue reading >>

What Happens When Lactate Levels Are High?

What Happens When Lactate Levels Are High?

What Happens When Lactate Levels Are High? Joseph Pritchard graduated from Our Lady of Fatima Medical School with a medical degree. He has spent almost a decade studying humanity. Dr. Pritchard writes as a San Francisco biology expert for a prominent website and thoroughly enjoys sharing the knowledge he has accumulated. Elevated lactate levels can affect your heart rhythm. Lactic acid is a by-product of the process cells use to produce energy. As cells convert glucose to energy, they use oxygen. If there is not enough oxygen within the cell, the cell is still able to produce energy, but also produces lactic acid. The cells releases lactic acid into the blood, where it is converted to a similar molecule called lactate. High lactate levels within the blood can harm your cells, the University of New Mexico warns. There are certain conditions that cause a decrease in oxygen levels and thus lactic acidosis. Severe hypoxia, such as in patients in shock, congestive heart failure, liver disease and lung disease are all possible causes of elevated lactate levels, according to MedlinePlus, a service of the National Institutes of Health. These diseases force the body to make energy without having enough oxygen. Elevated lactate levels can lead to severe complications. Lactic acidosis is a disorder that occurs when lactate levels in your bloodstream rise above the normal limits. Symptoms of this condition include an abnormal heartbeat, difficulty breathing, nausea, vomiting, muscle weakness, inflammation of the pancreas, fatigue, weight loss and enlargement of the liver, AidsHealth.org explains. If you experience these symptoms, immediately consult your doctor, as lactic acidosis is a potentially life-threatening condition. Measuring lactate levels requires a blood test called a Continue reading >>

Lactic Acidosis In A Patient With Type 2 Diabetes Mellitus

Lactic Acidosis In A Patient With Type 2 Diabetes Mellitus

Go to: Introduction A 49-year-old man presented to the emergency department complaining of dyspnea for 2 days. He had a history of hypertension, type 2 diabetes mellitus, atrial fibrillation, and a severe dilated cardiomyopathy. He had been hospitalized several times in the previous year for decompensated congestive heart failure (most recently, 1 month earlier). The plasma creatinine concentration was 1.13 mg/dl on discharge. Outpatient medications included insulin, digoxin, warfarin, spironolactone, metoprolol succinate, furosemide (80 mg two times per day; increased from 40 mg daily 1 month earlier), metolazone (2.5 mg daily; added 1 month earlier), and metformin (2500 mg in three divided doses; increased from 1000 mg 1 month earlier). Physical examination revealed an obese man in moderate respiratory distress. The temperature was 36.8°C, BP was 119/83 mmHg, and heart rate was 96 per minute. Peripheral hemoglobin oxygen saturation was 97% on room air, with a respiratory rate of 26 per minute. The heart rhythm was irregularly irregular; there was no S3 or murmur. Jugular venous pressure was about 8 cm. There was 1+ edema at the ankles. A chest radiograph showed cardiomegaly and central venous prominence. The N-terminal pro-B-type natriuretic peptide level was 5137 pg/ml (reference range = 1–138 pg/ml). The peripheral hemoglobin concentration was 12.5 g/dl, the white blood cell count was 12,500/µl (76% granulocytes), and the platelet count was 332,000/µL. Initial plasma chemistries are shown in Table 1. The impression was decompensated congestive heart failure. After administration of furosemide (160 mg intravenously), the urine output increased to 320 ml over the next 1 hour. There was no improvement in the dyspnea. Within 2 hours, the patient’s BP fell to 100/ Continue reading >>

Mala: Metformin-associated Lactic Acidosis

Mala: Metformin-associated Lactic Acidosis

By Charles W. O’Connell, MD Introduction Metformin is a first-line agent for type 2 diabetes mellitus often used as monotherapy or in combination with oral diabetic medications. It is a member of the biguanide class and its main intended effect is expressed by the inhibition of hepatic gluconeogenesis. In addition, metformin increases insulin sensitivity, enhances peripheral glucose utilization and decreases glucose uptake in the gastrointestinal tract. Phenformin, a previously used biguanide, as withdrawn from the market in the 1970’s due its association with numerous cases of lactic acidosis. Metformin is currently used extensively in the management of diabetes and is the most commonly prescribed biguanide worldwide. The therapeutic dosage of metformin ranges from 850 mg to a maximum of 3000 mg daily and is typically divided into twice daily dosing. It is primarily used in the treatment of diabetes but has been used in other conditions associated with insulin resistance such as polycystic ovarian syndrome. MALA is a rare but well reported event that occurs with both therapeutic use and overdose states. Case presentation A 22-year-old female presents to the Emergency Department after being found alongside a suicide note by her family. She was thought to have taken an unknown, but large amount of her husband’s metformin. She arrives at the ED nearly 10 hours after ingestion. She was agitated, but conversant. She reports having nausea and vague feelings of being unwell and is very distraught over the state of her critically ill husband. She has some self-inflicted superficial lacerations over her left anterior forearm. Her vital assigns upon arrival were: T 98.9 degrees Fahrenheit, HR initially 140 bpm which improved to 110 bpm soon after arrival, BP 100/50, RR 22, Continue reading >>

Lactic Acidosis

Lactic Acidosis

Type B Lactic acidosis type B is associated with certain diseases (e.g., diabetes mellitus), some drugs—notably biguanides, certain toxins, and some inborn errors of metabolism (Table I). Tissue hypoxia and hypotension are not obvious features of type B lactic acidosis but may supervene as a consequence of the acidemia. The incidence of lactic acidosis among patients with diabetes has declined since the biguanide phenformin (phenylethybiguanide) was withdrawn in many countries during the 1970s. Lactic acidosis occurred approximately 10–15 times more frequently during phenformin therapy than with metformin. An inherited inability to hydroxylate phenformin may explain the higher risk of lactic acidosis than with metformin. Lactic acidosis complicating metformin (dimethylbiguanide) occurs much less commonly, with most cases being reported among patients in whom biguanide therapy is contraindicated (e.g., renal impairment or hypoxic states). LACTIC ACIDOSIS Lactic acidosis occurs whenever lactate production exceeds its utilization. This can occur with tissue hypoxia or in nonhypoxemic conditions when cellular metabolism is impaired. Type A lactic acidosis is the hypoxic form. It can occur with true hypoxemia, severe anemia, reduced oxygen delivery from poor perfusion, or from dramatically increased tissue demand from exercise, convulsions, or heat stroke.1,3,4,7 Type B lactic acidosis is the nonhypoxic form. It occurs in the face of adequate oxygen delivery when mitochondrial oxidative function is abnormal. This can occur with drugs or toxins, hypoglycemia, diabetes mellitus, liver failure, renal failure, lymphosarcoma, sepsis, and inborn errors of metabolism (Box 60-1).1,2,4 PROGNOSIS AND FUTURE PERSPECTIVES Primary lactic acidosis of the neonate usually ends in death Continue reading >>

Causes Of Lactic Acidosis

Causes Of Lactic Acidosis

INTRODUCTION AND DEFINITION Lactate levels greater than 2 mmol/L represent hyperlactatemia, whereas lactic acidosis is generally defined as a serum lactate concentration above 4 mmol/L. Lactic acidosis is the most common cause of metabolic acidosis in hospitalized patients. Although the acidosis is usually associated with an elevated anion gap, moderately increased lactate levels can be observed with a normal anion gap (especially if hypoalbuminemia exists and the anion gap is not appropriately corrected). When lactic acidosis exists as an isolated acid-base disturbance, the arterial pH is reduced. However, other coexisting disorders can raise the pH into the normal range or even generate an elevated pH. (See "Approach to the adult with metabolic acidosis", section on 'Assessment of the serum anion gap' and "Simple and mixed acid-base disorders".) Lactic acidosis occurs when lactic acid production exceeds lactic acid clearance. The increase in lactate production is usually caused by impaired tissue oxygenation, either from decreased oxygen delivery or a defect in mitochondrial oxygen utilization. (See "Approach to the adult with metabolic acidosis".) The pathophysiology and causes of lactic acidosis will be reviewed here. The possible role of bicarbonate therapy in such patients is discussed separately. (See "Bicarbonate therapy in lactic acidosis".) PATHOPHYSIOLOGY A review of the biochemistry of lactate generation and metabolism is important in understanding the pathogenesis of lactic acidosis [1]. Both overproduction and reduced metabolism of lactate appear to be operative in most patients. Cellular lactate generation is influenced by the "redox state" of the cell. The redox state in the cellular cytoplasm is reflected by the ratio of oxidized and reduced nicotine ad Continue reading >>

Lactic Acidosis

Lactic Acidosis

The buildup of lactic acid in the bloodstream. This medical emergency most commonly results from oxygen deprivation in the body’s tissues, impaired liver function, respiratory failure, or cardiovascular disease. It can also be caused by a class of oral diabetes drugs called biguanides, which includes metformin (brand name Glucophage). Another biguanide called phenformin was pulled from the market in the United States in 1977 because of an unacceptably high rate of lactic acidosis associated with its use. Concerns about lactic acidosis also delayed the introduction of metformin to the U.S. market until 1995, despite the fact that it had been widely used for years in other countries. There have been reports of lactic acidosis occurring in people taking metformin, and the U.S. Food and Drug Administration estimates that lactic acidosis occurs in 5 out of every 100,000 people who use metformin for any length of time. However, this risk is much lower than it was in people taking phenformin, and it is not clear whether the episodes of lactic acidosis associated with metformin have actually been due to metformin use. In fact, the lactic acidosis could have been explained by the person’s diabetes and related medical conditions. Nonetheless, diabetes experts recommend that metformin not be used in people with congestive heart failure, kidney disease, or liver disease. They also recommend that it be discontinued (at least temporarily) in people undergoing certain medical imaging tests called contrast studies. Symptoms of lactic acidosis include feeling very weak or tired or having unusual muscle pain or unusual stomach discomfort. Continue reading >>

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