Metabolic Alkalosis


Metabolic alkalosis is a common problem affecting many individuals across the globe. Read on to know what is Metabolic alkalosis, its causes, symptoms, diagnosis, treatment and more.

Metabolic Alkalosis Definition

Medical researchers define metabolic alkalosis as a metabolic disorder that is marked by an increased pH level in the tissues that is well over the range within which it should be. It primarily refers to an elevation in the concentration of serum bicarbonate (HCO3).

This is a form of a condition known as Alkalosis in which there is presence of excess alkali (base) in the fluids of the human body.

Metabolic alkalosis Symptoms

Some of the main signs and symptoms of Metabolic Alkalosis (MA) are:

  • Tremors in hands
  • Mental confusion, which can result in semiconsciousness or even coma
  • Lightheadedness
  • Irritability
  • Prolonged spasms in the muscles (Tetany)
  • Twitching of the muscles
  • Vomiting
  • Nausea
  • Tingling sensations in the face
  • Facial numbness

Reduced rate of respiration is one of the initial symptoms of this condition. The disorder may also be marked by several gastrointestinal symptoms, including diarrhea, vomiting and nausea. Cardiovascular signs may include serious discomforts, such as

  • Increased heart rate
  • Irregularities in heart rate
  • Drop in blood pressure

Severe alkalosis may lead to convulsions and even coma.

Metabolic alkalosis Causes

This condition is basically a result of instability in the acid-base system of the human body. The term pH stands for the level of alkalinity or acidity of any substance. A pH value of 7.0 indicates neutrality. The pH value in a normal individual is moderately alkaline, within the range of 7.36 – 7.44. It is within this range that the body is designed to function to an optimum point. Adverse effects start occurring when the level of human blood becomes baser than acid, adverse effects will occur. The severity of the signs of this disease depends on the degree of alkalinity in the human body.

This disease is usually caused by factors that reduce the amount of fluids in the body, such as:

  • Vomiting
  • Overuse of laxatives
  • Excessive urination, resulting from use of diuretic medicines

The loss of fluids can result in a sharp drop in the level of sodium and potassium, which give rise to symptoms of Metabolic Alkalosis. Some other Metabolic Alkalosis causes include:

  • Use of steroids
  • Excessive of antacids
  • Overuse of alkaline drugs, like Bicarbonate

Metabolic Alkalosis Diagnosis

Alkalosis is diagnosed with the aid of a basic metabolic panel or an arterial blood gas analysis. These tests will confirm Alkalosis and help determine whether it is a Metabolic Alkalosis or a Respiratory Alkalosis. Other tests that may be required to ascertain the cause of the Alkalosis may include:

  • Urinalysis
  • Urine Dipstick Tests (with the aid of Litmus paper)
  • Urine pH

The diagnosis of Metabolic alkalosis is performed by measuring Arterial Blood Gases and Serum Electrolytes. A Urine Chloride Ion Concentration can come in handy if the cause of the disease is difficult to diagnose from physical examination and the clinical history of the patient, including the presence of Hypertension and drug use.

Metabolic Alkalosis Treatment

Treatment of Alkalosis depends on finding the specific cause. Once the cause is found out and the condition is detected to be Metabolic Alkalosis, the aim of treatment is to correct the acid-base imbalance in the bloodstream. Medications and salt-water solution needs to be administered to patients via an intravenous line. Medicative substances involve drugs to restore normalcy of heart rate and blood pressure along with Potassium Chloride (KCL). Potassium Chloride helps rectify problems like Hypokalemia that results from low Potassium level in the bloodstream. Medicines that provide relief from vomiting and nausea may also be administered. In some cases, use of Ammonium Chloride or Hydrochloric Acid may become necessary for treatment.

Some suffering individuals require medicines to compensate for loss of chemicals, such as Potassium and Chloride. Doctors monitor pulse rate, body temperature, blood pressure level, rate of breathing and other vital signs to detect any changes in the condition of the sufferers.

Individuals suffering from Alkalosis due to Hyperventilation should breathe into a paper bag. This will help them retain more carbon dioxide, thus improving their Alkalosis. If the level of oxygen is low, artificial air supply may help correct the condition.

Hypochloremic Metabolic Alkalosis

This is a variation of MA. A severe form of this condition manifests itself through different conditions such as psychomotor retardation and acute brain damage. The condition is believed to result due to diverse factors such as

  • Severe Iron Intoxication
  • Malnutrition
  • Hypoxia
  • Diethylene Glycol poisoning
  • Chronic Renal Failure
  • Hypovolemic shock

Hypokalemic Hypochloremic Metabolic Alkalosis

This is a discomforting condition that manifests through extremely discomforting symptoms like Pyloric Stenosis or Gastric Outlet Obstruction. It is said to occur due to electrolyte abnormality in the human body.

Compensated Metabolic Alkalosis

Compensation for metabolic alkalosis mainly takes place in the lungs. The lungs retain carbon dioxide (CO2) through hypoventilation (respiratory compensation) or slower rate of respiration. This is followed by consumption of Carbon Dioxide (CO2), thus reducing the pH level in the bloodstream. Though respiratory compensation occurs, it is incomplete.

The reduction in [H+] inhibits the pH-sensitive Peripheral Chemoreceptors. However, the retarded rate of respiration is followed by an elevation in PCO2 that may counterbalance the depression due to the action of the central Chemoreceptors. The Chemoreceptors are sensitive to the partial pressure exerted by Carbon Dioxide (CO2) in the bloodstream. It is due to the central Chemoreceptors that there is an elevation in the rate of respiration.

Renal metabolic alkalosis compensation, though less effectual than Respiratory Compensation, involves increase in excretion of HCO3- (bicarbonate). This is due to the filtered HCO3 load that surpasses the reabsorbing ability of the renal tubule.

Uncompensated Metabolic Alkalosis

An uncompensated metabolic alkalosis can be very risky for the health of a person. An inadequate ventilator response to this problem may lead to an imminent respiratory failure. Patients require immediate ventilator support and close monitoring to ward off any life-threatening complications.

Chloride Responsive Metabolic Alkalosis

This condition typically results from loss of protons and simultaneous gain of bicarbonates.  This commonly occurs in two cases –

  • During loss of gastric fluid that is acidic in nature (often accompanied by volume contraction)
  • In case of Diuretic Therapy

This disorder may also rarely arise due to lack of chloride in the sweat of suffering individuals suffering from

  • Deficiency of chloride in daily diet
  • Cystic Fibrosis

Metabolic Alkalosis Prognosis

If diagnosed and cured quickly, an MA patient is not likely to suffer from any long-term complications. However, the underlying disorder needs to be treated or managed properly. Most cases of this syndrome gets cured quickly if treated well in time and properly managed afterwards.

Metabolic Alkalosis Complications

If Severe Metabolic Alkalosis is left untreated, it may lead to any or all of these complications:

  • Convulsions
  • Heart failure
  • Coma

Metabolic Alkalosis Prevention

Patients receiving feedings in an intravenous or tubular manner must be carefully monitored to avoid an imbalance of salts and fluids, especially sodium, chloride and potassium. Excessive use of some drugs, such as antacids, laxatives and diuretics should be avoided.

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