What is Hypokalemic Metabolic Alkalosis?
Since the first creatures moved from the sea to land, they had to adjust to a new environment that wasn’t as rich in fluids and electrolytes as seawater. Over time, these animals developed kidneys that could control how much salt and water they stored. The parts of the kidney responsible for this control are the most distant sections of the nephron (the tiny units where the kidney does its work). When these sections don’t work properly, we may suffer from problems with our electrolytes – substances needed for many body functions – that seem unrelated but can be very dangerous, mainly low potassium levels (hypokalemia) and a condition where the body has too many base substances (metabolic alkalosis). This discussion will focus on the functions of specific parts of the nephron – the thick ascending limb and the distal convoluted tubule, as well as the connecting tubule and their primary cells.
What Causes Hypokalemic Metabolic Alkalosis?
Low blood pressure can be caused by both genetic and acquired diseases. Genetic diseases are those you inherit from your parents, while acquired diseases are those you get because of certain activities or situations.
Some genetic diseases that can cause low blood pressure are Bartter syndrome, Gitelman syndrome, and Autosomal Dominant Hypocalcemia with Hypercalciuria (ADHH). These are conditions you are born with that can cause your blood pressure to be lower than normal.
For acquired diseases, low blood pressure can result from the use of diuretics (a type of medication used to get rid of excess water and salt in your body) or from vomiting.
On the other hand, high blood pressure can also be caused by both genetic and acquired diseases.
Genetic diseases causing high blood pressure include Liddle Syndrome and a rare genetic defect that leads to an inactive 11-beta-HSdehydrogenase enzyme.
Acquired diseases that can cause high blood pressure include Conn disease or the formation of tumors in the adrenal glands (glands located at the top of your kidneys that produce hormones), Cushing disease (a condition that occurs from exposure to high cortisol levels), chronic use of corticosteroids (a type of medication), or abusing natural licorice. These are conditions or situations that are not inherent but developed throughout life that can cause your blood pressure to be higher than normal.
Risk Factors and Frequency for Hypokalemic Metabolic Alkalosis
The diseases we’re discussing are pretty rare. But the symptoms they cause are more common because they often show up when people take certain medicines too much. These are mostly diuretics (water pills) or steroids, or when people vomit a lot.
Your primary care doctor might see a condition called hypokalemic metabolic alkalosis. This can happen because of treatment with, or misuse of, certain prescribed medicines.
Signs and Symptoms of Hypokalemic Metabolic Alkalosis
When it comes to conditions like Bartter, Gittleman, and Liddle syndrome, there aren’t many noticeable signs. Nonetheless, a few key things to pay attention to could include:
- Varying blood pressure levels, either low or high
- Potential history of using or overusing medications
- Although less common, family history of these conditions
Testing for Hypokalemic Metabolic Alkalosis
For many patients, issues with potassium, bicarbonate, blood pressure, and other conditions are found during typical health check-ups, often during routine blood tests. Depending on what the tests show, doctors can start to identify what might be causing the problem.
If the blood tests and physical examination show low blood pressure, your doctor may need to carry out more tests, as outlined in previous sections. For example, they might measure the amount of calcium in your urine. If the calcium level in your urine is high, it may suggest conditions like Bartter syndrome or that a person may be taking, or even misusing, a type of medicine called loop diuretics. On the other hand, if urine calcium is low and magnesium level is also low, it may hint at conditions like Gitelman syndrome, or that a person may be using, or misusing, another type of drug called thiazides.
If blood tests show high blood pressure, the doctor may need to check the levels of two hormones – aldosterone and renin in the blood. Depending on what these tests show, they can help to diagnose three common conditions. If both renin and aldosterone levels are high, it could suggest a condition called primary reninism. If renin levels are low and aldosterone levels are high, it could indicate a condition known as primary hyperaldosteronism. Finally, if both renin and aldosterone levels are low, it could be a condition known as pseudohypoaldosteronism.
Treatment Options for Hypokalemic Metabolic Alkalosis
Treating low blood pressure can involve examining whether someone is using diuretics (medications that help your body get rid of salt and water) excessively or deliberately vomiting. Both of these behaviors can lead to low blood pressure. If these are the cause, treatment would focus on giving the patient plenty of fluids and potassium to help stabilize their blood pressure.
For high blood pressure, different treatments may be necessary. Hyperaldosteronism, a condition where your body produces too much of the hormone aldosterone, can increase your blood pressure. In this case, the diuretic medication spironolactone may be used to help decrease this hormone and lower blood pressure. Pseudohyperaldosteronism, though similar to hyperaldosteronism in its effect on blood pressure, might require a different medication, amiloride, to help regulate the body’s sodium and fluid levels. Both these conditions could also benefit from additional potassium.
Remember, it’s always important to discuss treatment options with your doctor who can provide the most appropriate and personalized care plan for your specific case.
What else can Hypokalemic Metabolic Alkalosis be?
When a doctor is trying to figure out a diagnosis based on a patient’s symptoms and medical history, there are many different conditions they need to consider. Some possibilities might include:
- Bartter syndrome (a rare disorder affecting the kidneys)
- Congenital chloride-losing diarrhea (a genetic disorder that affects the intestines)
- Effects of prolonged glucocorticoid therapy or having Cushing syndrome
- Hyperaldosteronism (a hormonal disorder)
- Hypercalciuria (excessive calcium in urine)
- Hypomagnesemia (low magnesium levels)
- Milk-alkali syndrome (a condition caused by consuming too much calcium)
- Pediatric conditions like hypercalcemia (high calcium levels), hypokalemia (low potassium levels), and hyponatremia (low sodium levels)
- Posthypercapnic alkalosis (a condition caused by a decrease in carbon dioxide in the blood)
- Sinonasal manifestations of cystic fibrosis (symptoms affecting the sinuses and nasal passages caused by the genetic disorder cystic fibrosis)
- Uric acid stones (kidney stones formed from uric acid)
These conditions are just a few examples of what may be considered when trying to reach a diagnosis. It’s crucial to have a thorough examination and analysis of symptoms to pinpoint the actual cause of the illness.
What to expect with Hypokalemic Metabolic Alkalosis
When it comes to genetic diseases that cause low blood pressure, most are detected in childhood. The symptoms can be more severe for some forms, like Bartter variety, than others, like Gitleman variety. Despite this, these conditions haven’t been seen to affect life expectancy.
On the other hand, for diseases causing high blood pressure, if a tumor (reninoma) is found, which can lead to increased levels of aldosterone (a hormone) and glucocorticoid (a group of hormones), it will need to be surgically removed. Genetic diseases can also lead to high blood pressure and its related complications such as strokes, heart disease, and end-stage kidney disease (the last stage of chronic kidney disease where the kidneys can no longer function on their own).
Certain conditions that induce these changes will need specific treatments, such as adjusting medication or a psychiatric evaluation. However, the general outlook for these patients is usually good.
Possible Complications When Diagnosed with Hypokalemic Metabolic Alkalosis
The diseases mentioned previously primarily pose two major health risks. The first being hypokalemia, a condition characterized by low potassium levels in your blood, which can lead to heart problems. The second risk is hypertension or high blood pressure.
Common Risks:
- Hypokalemia leading to heart complications
- Hypertension or high blood pressure
Preventing Hypokalemic Metabolic Alkalosis
Teaching patients about their health is extremely important. For example, if a patient is prescribed with a water pill (also called a diuretic), they need to be aware of the effects of using too much or too little of this medicine. They also need to know that if they start experiencing high blood pressure, feeling dizzy, or any unusual change in their usual behavior, they should immediately seek medical help.
