What is lactic acidosis?
Lactic acidosis is a type of acidosis that occurs when the blood becomes too acidic due to the presence of excess lactic acid in the body. Blood pH is tightly controlled because even slight changes in your pH can have severe effects on many organs. Normally, your blood is slightly basic, or alkaline. Acidosis occurs when the blood becomes more acidic than normal.
Lactic acid is created when structures in the cells called mitochondria respond to high-energy demands in cases of relatively low oxygen levels. Lactic acid commonly increases with exercises designed to increase speed, strength, and muscle mass, such as sprinting and lifting weights, but is typically cleared quickly during rest periods, mostly by the liver. Conditions that decrease blood oxygen levels, interfere with the mitochondria, or decrease the clearance of lactic acid can allow lactic acid to increase to harmful levels. As lactic acid builds up, symptoms such as nausea and vomiting, abdominal pain, weakness, rapid breathing, rapid heart rate or irregular heart rhythm, and mental status changes can occur.
Medical conditions that can cause lactic acidosis include severe infections, kidney or liver disease, respiratory disease, heart disease, seizures, shock, cancer, severe anemia, and diabetes. Although rare, lactic acidosis can occasionally occur with metformin, a diabetes medication, and nucleoside reverse transcriptase inhibitors (NRTIs), medications used to treat HIV and AIDS.
In order to correct lactic acidosis, the underlying problem needs to be addressed. Additional treatment of lactic acidosis may include intravenous fluids, supplemental oxygen or mechanical ventilation, and vitamins.
Lactic acidosis can be a serious condition leading to life-threatening complications such as shock. Seek immediate medical care (call 911) for serious symptoms, such as profuse sweating, bluish coloration of the lips and nails, chest pain, cold and clammy skin, rapid breathing, rapid heart rate, weakness, decreased or absent urine output, sweating, unusual anxiety, confusion, or unconsciousness.
Seek prompt medical care if you are being treated for lactic acidosis but mild symptoms recur or are persistent.
What are the symptoms of lactic acidosis?
Common symptoms of lactic acidosis
If you experience lactic acidosis, it may be accompanied by symptoms that include:
- Abdominal pain
- Irregular heart rate (arrhythmia)
- Nausea with or without vomiting
- Rapid breathing (tachypnea)
- Rapid heart rate (tachycardia)
- Shortness of breath
Serious symptoms that might indicate a life-threatening condition
In some cases, lactic acidosis can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:
- Bluish coloration of the lips or fingernails
- Change in level of consciousness or alertness, such as passing out or unresponsiveness
- Chest pain, chest tightness, chest pressure, palpitations
- High fever (higher than 101 degrees Fahrenheit)
- Not producing any urine, or an infant who does not produce the usual amount of wet diapers
- Rapid heart rate (tachycardia)
- Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, rapid breathing, or not breathing
- Severe abdominal pain
What causes lactic acidosis?
Lactic acid forms when the mitochondria, small structures inside of cells that act somewhat like batteries, need to utilize oxygen-free methods to produce energy. This occurs when energy demands are high and oxygen is not supplied as quickly as would be necessary to meet them. Exercises that involve quick bursts of activity, such as sprinting and power lifting, commonly result in mitochondrial lactic acid production. Generally, the lactic acid is removed from the blood during rest periods and does not create significant problems.
If lactic acid is produced more quickly than it is removed, it can build up and cause lactic acidosis. Conditions and medications that interfere with the mitochondria, decrease the amount of oxygen in the blood, or decrease the clearance of lactic acid can cause lactic acid to increase to harmful levels.
What are the risk factors for lactic acidosis?
A number of factors increase the risk of developing lactic acidosis. Not all people with risk factors will get lactic acidosis. Risk factors for lactic acidosis include:
Certain inherited metabolic disorders
Heart or lung disease
Highly stressful exercise without proper rest
Medications, including metformin (medication used to treat type 2 diabetes) and nucleoside reverse transcriptase inhibitors (NRTIs, medications used to treat HIV and AIDS), although rare unless other risk factors are present
How is lactic acidosis treated?
The main treatment for lactic acidosis is to correct the underlying problem that led to it. If lactic acid production can be slowed down, it is more likely that its clearance will be able to keep up with its production. Although substances can be given to decrease the acidity of your blood, the use of these can lead to a paradoxical increase in lactic acid production.
Common treatments for lactic acidosis
As the underlying cause is being assessed and managed, additional treatments may be given to support circulation and tissue oxygen delivery. These include:
Intravenous fluids to help support circulation
Mechanical ventilation to help enhance oxygen delivery to the lungs
Oxygen therapy to boost oxygen availability
Other treatments, such as vitamin therapy and dialysis, may be considered.
What are the potential complications of lactic acidosis?
Complications of untreated lactic acidosis can be severe, even life threatening in some cases. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of lactic acidosis include:
Arrhythmia (irregular heart rhythms)
Decreased athletic performance
Spread of infection
Unconsciousness and coma