Potassium deficiency

Synonyms

Hypokalemia, potassium deficiency

Basics

Potassium is an electrolyte (bulk element) that is especially important for the excitability of muscle and nerve cells and for the fluid and hormone balance. It must be supplied to the body regularly from the outside as a small amount is excreted every day. Potassium is found in large quantities in meat, fruit (bananas, apricots, figs, etc.), nuts and vegetables (potatoes).

Electrolytes are distributed in different rooms in the body after they are ingested through food. These are mainly that blood on the one and the Cell interiors and Intercellular spaces on the other hand. 99% of the body's potassium is found in the cell interior. Consequently, it lies in the cell interiors at a very high (~ 150 mmol / l, not directly determinable), in the blood very low (~ 4 mmol / l, can be determined by taking a blood sample) Concentration before. This Concentration difference must be sustained because it is critical to that Excitability of body cells (especially muscle / nerve cells).

In the short term, fluctuations in the blood concentration (e.g. due to food intake) are compensated for by the further shifting of potassium into the interior of cells; in the long term, an individually variable occurs in the kidneys Elimination in the urine. If the kidney function is insufficient, the Large intestine increasingly take on this task, which in healthy people plays a subordinate role in potassium excretion.

definition

The normal one Potassium concentration in the blood is 3.6-5.4 mmol / l. A concentration below 3.5 mmol / l is called Potassium deficiency (Hypokalemia), below 3.2 mmol / l this makes itself through physical symptoms mostly noticeable and under 2.5 mmol / l the potassium deficiency can be considered life threatening be considered.

Occurrence

The Potassium concentration in the blood is prone to fluctuations because of the amount of potassium and the Tolerance range relatively small are. It is a remarkable achievement of the body, in spite of the concentration in the blood Fluctuations in Ingestion keep constant. Accordingly is Potassium deficiency a common one Electrolyte disorder. The incidence is around 2-6% of inpatients in hospital, mostly through diuretic drugs (Diuretics) conditionally. Most of it is mild.

Emergence

A potassium deficiency can cause

• a loss of potassium,
• a disruption of the redistribution between blood and cell interiors,
• low potassium intake.

Loss of potassium from the kidney into the urine is the most common cause of potassium deficiency. This can have several causes. For the most part, these are certain diuretic drugs (Diuretics) crucial, especially the frequently prescribed loop diuretics (e.g. furosemide, torasemide) and the group of thiazides (e.g. hydrochlorothiazide / HCT). Due to the high fluid losses caused by drugs, the body excretes less water-binding sodium, but in return more potassium. Similarly, when high-dose penicillins are taken, potassium is lost.

Some hormone imbalances also cause potassium to be lost through the kidneys. The so-called hyperaldosteronism is characterized by high concentrations of the hormone aldosterone in the blood. In the event of high fluid excretion, aldosterone inhibits the excretion of sodium in the kidneys and excretes potassium as a counterbalance. An increased blood level leads to a loss of potassium. It can be caused by a benign aldosterone-producing adrenal tumor or an enlarged adrenal gland (Conn syndrome) be conditional. A sudden attack of high blood pressure, obstruction of a renal artery and frequent vomiting or frequent diarrhea also result in a pathological increase in aldosterone.

In Cushing's syndrome, the level of cortisol in the blood is increased. Cortisol does not usually affect electrolytes. If the blood concentrations are too high, however, it takes over the function of the structurally very similar aldosterone. During the drug treatment with cortisone preparations (= inactivated cortisol) and other glucocorticoids this mode of action is also possible. The risk of a potassium deficiency is particularly increased when taken at the same time as diuretics. Licorice also causes a higher excretion of potassium in a similar way.

In addition, certain nutritional conditions in the body influence the kidney's potassium balance. Frequent vomiting, poorly controlled diabetes with excess sugar, long starvation or low protein diets and certain diets (e.g. alkaline diet) also promote the development of a potassium deficiency. There are also genetic diseases such as Bartter syndrome and Gittelman syndrome, which cause a potassium deficiency due to their effect on the kidney.

A loss of potassium outside of the kidney occurs most often in the intestine through regular diarrhea or the use (abuse) of laxatives. Potassium is excreted in a similar way to the kidneys. Celiac disease can also lead to a potassium deficiency. Potassium losses through the skin can occur to a large extent in severe burns, in mild form when sweating under high temperatures and exertion.

Occasionally, a disturbance in the distribution of potassium between the blood and the cell interior is the reason for a potassium deficiency. If the potassium is forced into the cells, the concentration in the blood is reduced as a result. This is the case with a sharp rise in the blood pH value (hyperventilation, vomiting), with high insulin concentrations in the blood (through administration of insulin or with an acute excess of sugar) or with high concentrations of stress hormones (Adrenaline) in blood. The latter can be due to an adrenal tumor (Pheochromocytoma) or by giving it as a medication if the heartbeat is slow. Beta agonists (Asthma therapy) and caffeine also cause redistribution in the cells.

Ultimately, a reduced intake of potassium can also be the trigger. However, given the large amounts of stored potassium in the cells, it takes a long time for the concentration in the blood to change. In addition, the kidneys can greatly reduce the excretion of potassium when there is no food intake. As a result, only severe eating disorders (e.g. anorexia) or alcohol abuse can trigger a potassium deficiency due to decreased intake.

Symptoms

In general, a potassium deficiency lowers the excitability of the cells. Muscles and nerves are particularly affected, as they are particularly dependent on excitement. A slight potassium deficiency (3.5-3.2mmol / l) is usually not noticeable in people with healthy hearts. Physical symptoms are to be expected from a blood potassium level below 3.2 mmol / l, especially if it occurs suddenly. These include muscle weakness up to paralysis (occurring on both sides); however, muscle cramps can also occur. In addition, numbness and abnormal sensations such as tingling can occur.

The heart is prone to arrhythmias, which is noticeable by the feeling of a "palpitations" or "throbbing". A previous heart disease (e.g. heart attack) or treatment with the heart drug digitalis promotes this. As the bowel loses its mobility, it can become constipated. Furthermore, there may be a tendency to high blood sugar levels and increased urine excretion may occur. All of these symptoms are usually accompanied by a general tiredness. The doctor can often also recognize typical changes in the ECG. With a chronic potassium deficiency, such as in Gitelman syndrome, the body can adapt and the symptoms can disappear.

Diagnosis

To the Reason for the potassium deficiency To find out, the medication to be taken should first be checked. Especially on Diuretics (Drainage), beta agonists (against asthma), Penicillin antibiotics and insulin should be respected. Also diseases of the Gastrointestinal tract must be taken into account. Measurements of Blood gases and Electrolytes in the urine and blood help to find the cause. It is also not uncommon for further electrolyte imbalances to be discovered. If there is any suspicion hormonal causes (Hyperaldosteronism) the corresponding hormones in the blood can be checked. If you can't find the cause, hidden things will come too Vomit or abuse of Laxatives and alcohol in question. For the rare Gitelman Syndrome the mutated gene can be detected.

therapy

In the acute situation, the therapy goal is Compensation for the potassium deficiency. The missing amount of potassium can be calculated and should in the absence of severe symptoms in the form of potassium-rich food (Fruit, nuts, chocolate) or Tablets are given. With life-threatening phenomena (such as arrhythmias) can Potassium directly through the blood are given. However, care must be taken not to give too much potassium, otherwise one dangerous excess of potassium arises. Basically, however, action should be taken against the causative disease or triggering substances should be avoided.

forecast

Most cases of potassium deficiency are mild in nature. There is hardly any danger for healthy people. Only at Pre-existing heart conditions and at severe potassium deficiency consists risk of death, mainly due to Cardiac arrhythmias.

Potassium deficiency after surgery

After surgery it can happen that an incorrectly high potassium level is measured in the blood. This is because injuries or operations lead to massive breakdown of erythrocytes, i.e. the red blood cells. These contain a concentration of potassium up to 25 times higher than in serum.

However, a potassium deficiency can also develop after operations if, for example, it develops in the course of a Malnutrition due to a change in the intake of individual food components. Changed needs of the patient, decreased fluid intake, diarrhea, vomiting or other accompanying illnesses or the use of certain medications can play a role.
These include diuretics (so urine-promoting drugs), the insulin for diabetics or laxatives that are often given as part of the follow-up care after an operation. All of them cause an increased loss of potassium.

In addition, glucocorticoids are released in the body's physiological response to stress. These are hormones that are produced in the adrenal cortex and are intended to provide the body with increased energy readiness in a stressful situation, for example after an operation. To do this, they increase the blood sugar level and inhibit inflammatory reactions. But they also have an effect on the kidneys and cause an increased excretion of potassium in the urine at this point.

Potassium Deficiency During Pregnancy

During pregnancy, a healthy and balanced diet is essential for both mother and child.
The bigger the baby gets, the greater the need for vitamins, minerals and fluids.

Even the vital one potassium can become scarce during pregnancy. It is therefore important that pregnant women eat plenty of foods that contain potassium in order to counteract a possible potassium deficiency. These include, for example:

• Bananas
• Dried fruit
• Avocados
• Potatoes and
• nuts

It should also be noted that potassium levels are closely related to sodium levels. If you eat a lot of salt-rich food, the body excretes more potassium.
One way to save potassium is therefore to reduce the intake of table salt. A slight potassium deficiency can usually be remedied by adjusting your diet.

However, if the potassium deficiency is more pronounced, the potassium should be substituted in the form of tablets or other artificially manufactured preparations.
However, this should only be done in consultation with a doctor, since taking it independently can quickly lead to an excess of potassium, which can lead to paralysis and life-threatening Cardiac arrhythmias can go hand in hand.