Metabolic alkalosis is a shift in the pH of blood and extracellular tissues to levels above 7.45. The reason for this shift is primarily an increase in bicarbonate concentration, either by accumulation of bicarbonate via the kidney or by loss of acidic gastric juice during severe or chronic vomiting.
What is metabolic alkalosis?
In metabolic alkalosis, the body’s pH gets abundantly out of whack, which can be devastating to metabolic function. The word “metabolic” here indicates that the cause of this pH shift is also found in metabolism, or metabolism. The counterpart to this would be respiratory alkalosis, which has its cause in respiration.
Causes
The role of the kidney is a critical factor in the development of metabolic alkalosis: Bicarbonate is an important buffering system in the blood, which has the sole task of regulating pH. To achieve this, a bicarbonate ion can combine with a proton (“acid”) and remove it from circulation. It then converts to carbon dioxide and water, and the carbon dioxide molecule can be exhaled through the lungs and is finally excreted. With the help of bicarbonate, acid can be removed from circulation, which is constantly produced in our body, for example during muscle work. In order to remove bicarbonate from circulation, the kidney is needed. The kidney filters bicarbonate out of the blood in large quantities and then, in its widely ramified system of collecting tubes, only takes as much bicarbonate back into the blood as is needed for buffering. If this complexly regulated system is disturbed, for example by taking diuretics, it can easily happen that too little bicarbonate is excreted and consequently the pH value of the blood is changed to alkaline by acid binding – a metabolic alkalosis has developed. In addition to the side effect of diuretic therapy as one of the main causes of metabolic alkalosis, there are also shifts in potassium and chloride levels, which are also related to the acid-base balance of the body via the kidney. Since chloride and bicarbonate are both negatively charged ions, they can be readily exchanged with each other through the cell wall – if the body lacks chloride, it can replace it in the short term with bicarbonate molecules, which then ensures electrical equality, but also leads to alkalosis. Chronic vomiting is a possible cause of this problem: gastric juice consists of hydrochloric acid, i.e. protons and chloride; thus acid is directly lost to the body and indirectly, thanks to the lack of chloride, bicarbonate is also saved at the kidney and floods the metabolism. Potassium, on the other hand, is exchanged for protons; therefore, in diseases with potassium deficiency, metabolic alkalosis may occur. Hormonal disturbances (mineralocorticoid excess) can be causative here. Conversely, metabolic alkalosis also leads to an increased shift of potassium into cells in exchange for acidic protons.
Symptoms, complaints, and signs
The clinical picture of metabolic alkalosis is characterized by a drop in blood pressure, including weakness, confusion, and skin insensitivity. Sufferers experience a strong feeling of malaise, which appears suddenly and becomes stronger as it progresses. As a result of the imbalance of pH, convulsions and breathing difficulties occur. In severe cases, life-threatening respiratory depression occurs. Metabolic alkalosis may also be manifested by apathy, visual disturbances, ringing in the ears, feeling of heat, and cardiac arrhythmias. The most obvious sign is the characteristic position of the hands, which are cramped and slightly bent forward. A potassium deficiency may be detected during the medical examination. If this is not treated immediately, further health problems may occur. For example, there is a risk of developing deficiency symptoms (for example, faintness and dizziness). In addition, the cramps increase in intensity and sometimes cause severe pain in the affected person. If metabolic alkalosis is left untreated, it can lead to heart failure. Permanent damage to the internal organs and blood vessels cannot be ruled out either. However, with early treatment, serious complications such as these can be reliably avoided.The cramps usually subside within a few days to weeks.
Diagnosis and course
The symptomatology of metabolic alkalosis is usually determined by low potassium levels: Abnormal sensations on the skin, muscle weakness, and dangerous cardiac arrhythmias may occur. As with respiratory alkalosis, however, cramps and the typical “pawing” of the hands may also occur. Overall, severe metabolic alkalosis is quite rare and therefore often overlooked. A simple collection of capillary blood to perform a blood gas analysis (ABG) can reveal the problem: Measurement of pH and bicarbonate concentration unmistakably indicate metabolic alkalosis, and potassium and chloride levels can provide information about the cause.
Complications
In the worst case, this complaint can cause the death of the patient. However, this occurs very rarely and can be avoided with prompt and early treatment. Patients themselves suffer from severe respiratory distress and potassium deficiency. The lack of potassium has a negative effect on the patient’s health. There is a general weakness, the patient feels a noticeable lassitude. Likewise, the ability to work under pressure decreases significantly and cramps occur in the muscles. These cramps can lead to severe pain and to unpleasant feelings, thus considerably reducing the patient’s quality of life. Furthermore, confusion also sets in, so that ordinary thinking and acting is usually no longer possible for the affected person. Without treatment, it can also cause discomfort to the heart, so that cardiac death can occur. Treatment of this disease can be done by infusions and other medications or supplements. Complications do not occur and the symptoms can be relatively well limited. If treatment is successful, the life expectancy of the affected person is also not reduced.
When should you see a doctor?
Confusion, a general weakness, and a decrease in usual exercise tolerance are signs of an existing irregularity. If the symptoms persist or increase in intensity, a doctor is needed. If sensory or perceptual disturbances of the skin occur, this is considered an indication of an existing disorder. If there is a tingling sensation on the skin, an unpleasant feeling when touched, or hypersensitivity, a visit to the doctor is advised. In case of disturbances of the heart rhythm, a feeling of strong heat development in the body as well as sweating, a doctor should be consulted. Since metabolic alkalosis can lead to premature death in severe cases if left untreated, a check-up visit to a doctor should be made at the first signs and symptoms. Hardening of the muscles, a reduction in muscle strength or a general feeling of pain in the organism should be examined and treated. Apathy, fatigue, dysfunction, and problems with vision or hearing should also be evaluated by a physician. Ringing in the ears, breathing and heart murmurs are of concern and should be attended to immediately by a physician. Possible heart failure must be prevented as soon as possible. Cramps in the hands or an abnormality in the natural posture of the hands are signs of disease. If the hands are repeatedly bent slightly forward in everyday life, this is an indication of metabolic alkalosis.
Treatment and therapy
For therapy of metabolic alkalosis, the distinction between the different forms is crucial:
If there is a chloride and blood volume deficiency (e.g., after vomiting), administration of sodium or potassium chloride as an infusion by a physician is sufficient to restore acid-base balance. If the patient is taking a diuretic, the medication in question should be discontinued or a so-called potassium-saving diuretic should be added. If disorders of hormone metabolism are the underlying cause, more extensive drug therapy and sometimes surgical intervention are necessary.
Outlook and prognosis
With prompt and good medical care, the prognosis of metabolic alkalosis is favorable. Medication is given to relieve the existing symptoms. The pH is regulated and improvement in overall health occurs. As soon as side effects of the prescribed preparations occur, they are replaced by alternative products.Nevertheless, a chronic or unfavorable course of the disease can also develop. If left untreated, metabolic alkalosis can lead to the premature demise of the affected individual. Health irregularities increase and at the same time there is a decreased quality of life. Severe pain, internal weakness, cognitive changes and seizures can be expected. If the patient refuses to cooperate with a physician, his or her life expectancy is significantly reduced. In an advanced stage of the disease, various complications may also occur. Nevertheless, the survival of the affected person is ensured in these cases. If the drug therapy does not take effect as desired, a surgical intervention is performed. This is associated with risks, but it is the only way to help improve health in cases of advanced disease or chronicity of symptoms. In most cases, long-term therapy is necessary to achieve lasting relief of the symptoms. The pH must be monitored at regular intervals, and corrective measures are necessary if needed.
Prevention
Prophylactically, only regular monitoring of diuretic therapy can be recommended to avoid the sometimes severe consequences of metabolic alkalosis. In cases of severe or persistent vomiting, a ABG should also be performed to detect acid-base balance disorders in time and to be able to take countermeasures.
Follow-up
In most cases, no direct follow-up is possible or necessary for metabolic alkalosis. Affected individuals rely on treatment for this condition to prevent further symptoms and complications. If the alkalosis is not treated, the patient will die in most cases. For this reason, early diagnosis and treatment of metabolic alkalosis have a very positive effect on the further course of the disease. If the disease is treated by surgical intervention, the patient must rest and take care of his body after such an intervention. Therefore, strenuous activities or sporting activities should be refrained from. Furthermore, potassium can also be taken to alleviate the symptoms of alkalosis. Patients should pay attention to regular intake. In case the alkalosis was caused by a medication, it is recommended to discontinue this medication. Only in this way can the condition be fully treated. However, discontinuation of medication should be done only after consulting a doctor. In some cases, the disease also reduces the life expectancy of the patient. However, this is highly dependent on the underlying disease.
What you can do yourself
If metabolic alkalosis is present, it is usually sufficient to discontinue the responsible medication. Other self-help measures focus on alleviating the individual symptoms. For example, general weakness can be counteracted by exercise in the fresh air. Especially in the first few days after treatment, the immune system first needs to get going again, which is why exercise is particularly recommended here. Treatment is not necessarily required for cramps and confusion. In most cases, the symptoms disappear on their own as soon as the alkalosis is overcome. This process can be accelerated by rest and bed rest. Patients should get plenty of sleep during the acute phase and preferably take two to three days’ sick leave. Accompanying this, some household and natural remedies can be resorted to. For cramps, preparations with magnesium as well as calming teas (e.g. chamomile or lemon balm) help. Homeopathy recommends, among others, the remedies Cuprum metallicum, Magnesium phosphoricum and Cina. For confusion or difficulty concentrating, warm infusions or woodruff tea help. Belladonna, Glonoinum and Rhus Toxicodendron are effective homeopathic alternatives.
