Hypokalaemia is a drop in the level of potassium in the blood. It can have serious consequences on heart function. This loss of potassium is treated with oral or intravenous potassium intake. 

Definition

Hypokalaemia is defined as a plasma potassium (ion) concentration of less than 3,5 mmol. Serum potassium, the plasma potassium concentration, is normally around 4 mmol / L. It depends on the external (ingestion of potassium, supplied in particular by fruits and vegetables) and internal (mainly renal elimination) balances of potassium. Discrete or moderate hypokalaemia (3,0-3,5 mmol / L) is generally well tolerated by healthy people but it can have serious consequences when it is severe (less than 2,5mol / L), of rapid installation and that it occurs in an elderly person with fragile ground. 

Causes

Three mechanisms are at the origin of hypokalaemia:

• A decrease in potassium intake (in case of anorexia or a diet rich in carbohydrates associated with chronic alcohol consumption for example)
• An increase in gastrointestinal or urinary excretion (diarrhea, vomiting, abuse of laxatives, use or abuse of diuretics, etc.). Diuretics are the most common cause of hypokalaemia. 
• The transfer of potassium into the cell (stressful situations, insulin intake, metabolic alkalosis, certain drugs such as b2 mimetics, theophylline, caffeine). 

Diagnostic 

The diagnosis of hypokalaemia is made by questioning (taking diuretics or laxatives? Nausea or vomiting? Family history?), A clinical examination, the determination of serum potassium (plasma potassium concentration). Other biological examinations can be carried out: plasma and urinary bicarbonates, magnesemia, Ph, urinary chlorine and sodium.  

An electrocardiogram is performed to assess the severity of the hypokalaemia and see its cardiac effects.

The people concerned 

Hypokalemia is an extremely common hydroelectric disorder. It is present in 20% of hospitalized patients and in 10-40% of patients under treatment with thiazide diuretics.

Risk factors 

Long-term intake of diuretics is a risk factor for hypokalaemia -They are the most common cause of hypokalaemia-, as is excessive intake of laxatives and certain drugs: B2-mimetics, insulin, glucocorticoids, etc. certain plants (licorice, senna, buckthorn, boldo, etc.) is also a risk factor for hypokalaemia. 

Hypokalaemia is often asymptotic 

Hypokalaemia is often discovered incidentally during a biological workup. It is generally well tolerated in healthy people. 

Signs of moderate to severe hypokalaemia 

When the hypokalaemia is moderate to severe, it can cause non-specific signs: muscle weakness, muscle pain, fatigue. In people with underlying cardiac pathology, mild to moderate hypokalaemia may lead to cardiac arrhythmias. 

Symptoms of very severe hypokalaemia 

When the hypokalaemia is very severe (less than 2,0 mmol / L), there may be muscle damage with rhabdomyolise (massive and acute destruction of muscle tissue), tetraparesis (mild 4 limb paralysis), muscle fiber damage smooth with paralytic ileus (intestinal obstruction due to paralysis of the small intestine), urinary retention and ultimately respiratory arrest.

Treatment of hypokalaemia consists of managing the cause of the hypokalaemia and supplementing with potassium chloride orally for moderate hypokalaemia or intravenously for severe hypokalaemia. 

When the hypokalaemia is moderate and does not give any symptoms, in people with no cardiac history, a diet rich in potassium is generally sufficient (dried fruits, bananas, cocoa, meat and fish, grapefruit, etc.). If hypokalaemia persists, then drug supplementation is necessary. 

In prevention of hypokalaemia, the potassium level can be monitored in people at risk taking diuretics: these are those with heart disease, asthmatics on B2-agonists, those taking Digoxin, a medicine for the heart .