Acidosis
Information on the causes, symptoms, and treatments of excessive acidity in body fluids.
Symptoms and Causes
Acidosis is an increase in acidity in body fluids, which disrupts the acid-base balance. When blood—the primary fluid affected—has a pH below 7.35 (normally 7.35–7.45), organ dysfunction begins to manifest, which can become severe.
Depending on the origin of the condition, there are two main types of acidosis:
- Respiratory acidosis: occurs when the lungs do not ventilate adequately, preventing the complete elimination of carbon dioxide (CO₂) through respiration, which then accumulates in the blood and other body fluids.
- Metabolic acidosis: may result from excessive acid production or excessive bicarbonate (HCO₃⁻) loss, which normally acts as a buffer to neutralize acids.
The prognosis of acidosis varies depending on its cause and severity. Acute, reversible conditions typically resolve without complications. However, chronic conditions may result in prolonged symptoms or lead to more severe pathologies. With current treatments, patients commonly recover without significant reduction in life expectancy.
Symptoms
Each type of acidosis presents distinct symptoms, the most notable being:
- Respiratory acidosis:
- Drowsiness
- Headache
- Hypoxia: insufficient oxygen in tissues
- Tremors
- In severe cases, shock: inadequate blood supply to organs
- Metabolic acidosis:
- Fatigue
- Nausea
- Vomiting
- Rapid, deep breathing due to respiratory compensation attempting to eliminate excess CO₂
- Extreme weakness
- Drowsiness
- Confusion
- Abdominal pain
Causes
The causes of acidosis can be highly variable:
- Respiratory acidosis: usually secondary to one of the following conditions:
- Chronic obstructive pulmonary disease (COPD)
- Severe pneumonia
- Asthma
- Heart failure
- Amyotrophic lateral sclerosis (ALS), due to impaired breathing
- Narcotic abuse
- Sedative or hypnotic toxicity
- Sleep apnea (may cause transient acidosis)
- Metabolic acidosis: can be further classified as:
- Diabetic ketoacidosis: a complication of diabetes mellitus in which fat is broken down too rapidly. Fat is converted to ketone bodies in the liver, increasing blood acidity.
- Lactic acidosis: accumulation of lactic acid in the blood due to:
- Metabolic dysfunction: liver or kidneys not functioning properly
- Tissue hypoxia caused by stroke, shock, or heart failure
- Genetic disorders: congenital diseases preventing carbohydrate utilization for energy
- Certain medications: metformin (for diabetes), nucleoside reverse transcriptase inhibitors (for HIV), propofol (anesthetic), beta-adrenergic agonists (for asthma), epinephrine (for anaphylaxis)
- Hyperchloremic acidosis: bicarbonate levels in the blood decrease while chloride levels rise. Causes include:
- Diarrhea
- Renal tubular acidosis
- Excess saline administration in critically ill patients
- Renal failure: kidneys cannot excrete acid in urine despite normal acid levels in the body
- Toxin-induced acidosis: ingestion of medications or toxic agents metabolized into acidic compounds
Risk Factors
The risk of acidosis increases in the presence of conditions that predispose to it, mainly:
- Kidney disease
- Liver disease
- Diabetes mellitus
- Alcoholism
- Asthma
- COPD
- Excessive exercise
- Carbon monoxide poisoning
Complications
The most frequent complications of acidosis are:
- Metabolic acidosis:
- Osteoporosis and increased fracture risk
- Loss of muscle mass
- Inflammation
- Joint or brain damage due to amyloid protein accumulation
- Worsening of kidney disease
- Endocrine disorders
- Growth retardation
- Death
- Respiratory acidosis:
- Acute respiratory distress
- Respiratory failure
- Cognitive impairment
- Cardiovascular problems
- Shock
- Death
Prevention
Acidosis can be prevented by maintaining adequate control of conditions that may trigger it, such as diabetes, COPD, kidney disease, or liver disorders. Additionally, adopting a healthy lifestyle is recommended:
- Maintain a balanced diet
- Engage in regular physical activity
- Avoid smoking
- Limit alcohol consumption
Which Physician Treats Acidosis?
Management of acidosis involves different specialists depending on its cause. Typically, treatment is provided in nephrology, endocrinology and nutrition, or emergency department.
Diagnosis
Acidosis diagnosis includes the following tests:
- Medical history: assessment of the patient’s personal and family history along with current symptoms
- Blood gas analysis: arterial or venous blood sample to measure oxygen, carbon dioxide, and pH levels
- Blood tests: evaluation of bicarbonate, lactate, electrolytes, and ketones; also assesses renal function
- Urinalysis: evaluates urine pH, electrolyte levels, and osmolality (concentration of dissolved particles); useful for assessing the anion gap and kidney function
Treatment
Acidosis treatment focuses on correcting the underlying cause, requiring different approaches depending on the type:
- Intravenous bicarbonate: regulates blood pH in severe metabolic acidosis; must be carefully monitored to avoid complications
- Insulin: corrects hyperglycemia to reverse diabetic acidosis
- Fluid and electrolyte replacement: manages both diabetic ketoacidosis and lactic acidosis
- Oral antibiotics: effective in some forms of lactic acidosis
- Bronchodilators: open airways to improve gas exchange in patients with respiratory acidosis due to asthma or COPD
- Mechanical ventilation: assists patients with breathing difficulties, commonly used in respiratory failure
- Oxygen therapy: supplemental oxygen for chronic pulmonary diseases
