Overview of Metabolic Acidosis
Metabolic acidosis is a pathophysiological state caused by the increase of acid in the blood and/or the loss of HCO3-, which is manifested by abnormal respiration, abnormal neurological function, etc. It can not be cured by physiological factors, pathological factors, or medical factors. However, it can be alleviated or cured by timely treatment; severe primary disease or untimely treatment can be life-threatening.
What is metabolic acidosis?
Definition
Metabolic acidosis is a pathophysiological condition characterized by a primary decrease in plasma HCO3- due to an increase in acidity and/or loss of HCO3- in the blood, and is the most common clinical disorder of acid-base balance.
Typing
According to the values of plasma anion gap (AG) and chloride (Cl-), it can be divided into the following two types.
High AG normal chloride type metabolic acidosis
AG is elevated while Cl- is within the normal range.
It can be caused by seizures, strenuous exercise, cirrhosis of the liver, uremia, medications, poisons, etc.
It can also be categorized as lactic acidosis, ketoacidosis, etc. depending on the substance causing the acidosis.
Normal AG hyperchloremic metabolic acidosis
AG is within the normal range while Cl- is elevated.
Caused by renal or extra-renal loss of hydrogen ions (H+), or reduced renal tubular secretion of H+.
Extrarenal factors include severe diarrhea, intestinal obstruction, intestinal decompression or fistula treatment, urethral bypass surgery, and infusion of nutrient solutions containing acid salts; renal factors include renal tubular disease and chronic renal insufficiency.
Questions you may be concerned about
What is the difference between metabolic acidosis and respiratory acidosis?
Metabolic acidosis: caused by too many hydrogen ions in the body, or too much loss of bicarbonate. Common causes such as renal failure, diabetic ketoacidosis. Treatment should correct the acid-base balance and treat the primary disease.
Respiratory acidosis: respiratory dysfunction leading to carbon dioxide excretion is limited, resulting in carbon dioxide retention. Common causes such as chronic obstructive pulmonary disease, bronchial asthma or myasthenia gravis. Treatment is to improve ventilation and correct acid-base balance.
Can metabolic acidosis be cured?
In most patients, metabolic acidosis can be cured when the primary disease is relieved or cured.
Common causes of metabolic acidosis include renal failure, various types of shock leading to lactic acidosis, or diabetic ketoacidosis and diarrhea.
Metabolic acidosis is treated with rehydration, and most have a better prognosis. However, while treating acidosis, it is necessary to treat the primary disease at the same time in order to achieve the desired therapeutic effect.
When metabolic acidosis occurs, you should go to the emergency department of the hospital for treatment.
What organs are involved in metabolic acidosis?
When the disease is mild, there are no obvious symptoms. In more severe cases, the following organs appear to be damaged:
Respiratory system: increased respiratory rate and deepening of the amplitude.
Cardiovascular system: Severe metabolic acidosis can lead to ventricular arrhythmias, which can lead to fainting and cardiac arrest.
Central nervous system: vertigo, drowsiness, unresponsiveness, irritability, etc. Can be life-threatening due to paralysis of the respiratory center.
Digestive system: mild abdominal pain, diarrhea, nausea, vomiting, loss of appetite, etc.
Causes
Causes
Physiological factors
Severe hunger, strenuous exercise, etc.
Pathologic factors
Diseases: diabetic ketoacidosis, infectious diseases, epileptic seizures, cirrhosis of the liver, renal disease (e.g. uremia), intestinal obstruction, etc.
Poisoning: carbon monoxide poisoning, alcohol poisoning, methanol poisoning, etc.
Other: any condition leading to severe diarrhea, shock, cardiac arrest.
Medical factors
Drugs: large amounts of aspirin, long-term use of ammonium chloride, use of arginine hydrochloride or lysine hydrochloride, etc.
Surgery: fistula surgery, urethral bypass surgery, etc.
Other treatments: intestinal decompression, etc.
Symptoms
Main symptoms
There may be no obvious symptoms when the disease is mild, and the following symptoms may appear when the disease is more severe.
Respiratory system: mainly manifested as accelerated respiratory rate and deepened amplitude.
Cardiovascular system: severe metabolic acidosis can lead to ventricular arrhythmia (such as ventricular fibrillation), reduced myocardial contractility, palpitations, cardiac arrest, and in severe cases, syncope and cardiac arrest.
Central nervous system: dizziness, drowsiness, unresponsiveness, irritability and other symptoms may occur, and death may occur due to paralysis of the respiratory center.
Digestive system: mild abdominal pain, diarrhea, nausea, vomiting and loss of appetite may occur.
Other: symptoms such as fatigue may also occur.
Other symptoms
Mostly symptoms of the primary disease, some of which are listed below.
In diabetic ketoacidosis, there may be a sour odor in the exhaled breath, flushing, increased heart rate, decreased blood pressure, abdominal pain, diarrhea, nausea, vomiting and other symptoms, and in severe cases, delirium and coma may occur.
In severe cases, confusion and coma may occur. Those with cirrhosis of the liver may also have symptoms such as loss of appetite, abdominal distension, liver palms, and spider moles.
Kidney disease may cause symptoms such as decreased or absent urine output, foamy urine, edema, and dark complexion.
Consultation
Department of Medicine
Emergency Department
If you experience symptoms such as rapid and deepened breathing, unresponsiveness, drowsiness, or even coma, it is recommended that you go to the Emergency Department immediately or call the 120 emergency number.
Preparation for Medical Treatment
Preparing for the Consultation: Registration, Documentation, Frequently Asked Questions
Tips for Medical Care
It is recommended to wear loose-fitting clothing to make it easier to complete the examination.
If you have a history of diabetes, it is recommended that you bring a recent blood glucose record.
Preparation Checklist
Symptom Checklist
Particular attention should be paid to the time of onset of symptoms, special manifestations, etc.
How long has the change in breathing been present?
Are there any other discomforts, such as panic, nausea, etc.?
Medical history checklist
Are there any chronic illnesses, such as diabetes, cirrhosis of the liver, kidney failure, etc.?
Was there any heavy drinking, gas poisoning, etc. prior to the onset of symptoms?
Has there been any recent severe starvation, strenuous exercise, etc.?
Has there been any recent treatment such as fistula surgery, gastric tube, etc.?
Checklist
Test results in the last six months, which can be brought to the doctor’s office
Laboratory tests: liver function, kidney function, blood glucose, blood gas analysis
Medication list
Medication in the last 3 months, if available in box or package, bring with you to the doctor’s office
Glucose-lowering drugs: insulin
Others: aspirin, ammonium chloride
Diagnosis
Diagnosis based on
Medical history
Presence of severe hunger, strenuous exercise, etc.
Has diabetes, epilepsy, cirrhosis of the liver, kidney disease, etc.
Has used large amounts of aspirin, long-term use of ammonium chloride, and other medications.
Has undergone treatment such as fistula surgery, urethral bypass surgery, and intestinal decompression.
Clinical manifestations
Increased respiratory rate, deepening amplitude, vertigo, drowsiness, unresponsiveness, and irritability.
Laboratory Tests
Arterial blood gas analysis
Oxygen saturation, partial pressure of oxygen, partial pressure of carbon dioxide, bicarbonate (HCO3-), pH, base remaining (BE), standard bicarbonate (SB), actual bicarbonate (AB), and buffered base (BB) can be checked in arterial blood.
A decrease in HCO3-, pH, BE, SB, AB, and BB can be found.
Precautions.
Arterial blood will be drawn from the radial artery (wrist) or femoral artery (thigh root).
After drawing blood, forceful pressure should be applied to the area where the blood was drawn until the vessel stops bleeding.
If localized bulging of the skin, blood flow, etc. is detected, notify the doctor promptly while increasing pressure.
Biochemical examination
Check kidney function, liver function, blood glucose, etc.
It can clarify the original disease and the severity of the disease.
Note: There is no need to fast for emergency examination.
Differential Diagnosis
The diagnosis can be clarified according to arterial blood gas analysis, and it is generally not necessary to differentiate with other diseases.
A variety of factors can cause metabolic acidosis, so it is necessary to combine the medical history, clinical manifestations, laboratory tests to determine the cause of the disease.
Clarifying the cause of the disease can provide information for determining the treatment plan, which can improve the treatment effect and promote the patient’s recovery.
Treatment
Principle of treatment: treat the cause of the disease and correct the acidosis.
Treatment of etiology
Removing the cause of the disease is the basic principle and main measure of treatment.
For infectious diseases, anti-infective and rehydration treatment is necessary, and antibacterial drugs (e.g. cephalosporins, macrolides, etc.), large quantities of saline and glucose solution, etc. may be used.
For diabetic ketoacidosis, blood glucose control and rehydration, insulin, large amounts of saline and dextrose solution are commonly used.
Correction of acidosis
In severe cases where plasma HCO3- is less than 10 mmol/L, the pH is improved by neutralizing the acid in the plasma.
A commonly used drug is sodium bicarbonate. Simultaneous rehydration therapy is required.
Precautions
Acidosis is often associated with significant gastrointestinal symptoms, so oral sodium bicarbonate is often unsatisfactory and is usually administered intravenously.
Overdose may result in increased cardiac load.
Too rapid correction of acidosis may lead to hypocalcemia and convulsions of the hands and feet, which may be treated or prevented with calcium gluconate.
Sodium bicarbonate may cause potassium to shift into the cells and hypokalemia may occur, which may be treated or prevented with potassium chloride if necessary.
Prognosis
Cure
Most patients can be cured of metabolic acidosis with prompt treatment when the primary disease is in remission or cured.
Harmfulness
It can cause symptoms such as abnormal respiration and abnormal nerve function, causing discomfort and affecting life.
If the primary disease is severe and untreated, serious conditions such as coma may occur and may be life-threatening.
Daily
Work and rest management
Rest in bed and avoid exertion.
Ensure adequate sleep and avoid staying up late.
Dietary management
Ensure that the diet is nutritious and well-balanced. Choose the amount of food such as meat, dairy, soy products, fish, fresh fruits and vegetables.
Drink water according to the doctor’s requirements, which can be taken in small amounts and several times, avoid drinking too much at one time.
If you cannot eat, you can choose nasal food, which should be stirred before injecting into the nasal feeding tube.
Avoid spicy and stimulating foods or drinks, such as raw onions, ginger, garlic, chili peppers, strong tea, coffee and alcohol.
Exercise management
When resting in bed, elevation, flexion and extension can be done.
If you can get out of bed, you should move slowly to avoid falling. At the beginning, you can use walking aids, crutches and other aids, or be assisted by others.
If physical strength has been recovered, you can choose activities such as slow walking, fast walking, jogging, etc., or choose the activity program according to the doctor’s advice.
Exercise intensity should be gradual.
If you feel tired or uncomfortable during exercise, stop exercising immediately.
Emotion management
Tension and anxiety can be relieved by listening to soft music and reading books.
Family members should communicate with the patient and help him/her to relieve his/her emotions.
Follow-up
Follow the doctor’s instructions for regular review.
If symptoms do not subside or worsen, or new symptoms appear, consult a doctor promptly.
Prevention
Eat on time and in quantity to avoid dieting and excessive hunger.
Drink alcohol in moderation to avoid alcohol poisoning; avoid drinking fake alcohol.
Choose exercises suitable for your physical state, step by step, and avoid strenuous exercise.
Actively treat physical illnesses, such as diabetes, infections, epilepsy, cirrhosis, kidney disease, etc., to stabilize the condition and avoid or delay complications.
Use medication according to the doctor’s requirement; if there is any discomfort during the use of medication, stop the medication immediately and consult the doctor promptly.
During the treatment of fistula surgery, urethral bypass surgery, intestinal decompression, etc., the adjuvant treatment should be carried out according to the doctor’s prescription.