Guidelines in emergency medicine
In emergency medical care, guidelines exist for the adequate diagnosis and treatment of electrolyte disorders caused by hyperkalemia. A separate guideline for hyperkalemia does not exist. However, it is mentioned in the context of other guidelines, for example in the case of arterial hypertension.
In clinical diagnostics, the determination of electrolytes, a blood gas analysis, kidney values and the ECG play an important role. The therapeutic agents used are diuretics, infusions of glucose and insulin, balancing the acidic pH value by means of infusion and the treatment of changes in the ECG. So-called cation exchangers, for example resonium, bind potassium in exchange with sodium in the intestine. Hemodialysis lasting three to four hours serves to eliminate the potassium outside the body and is considered when potassium levels are particularly high.
Therapy with glucose and insulin
If hyperkalemia becomes symptomatic, it is an acutely life-threatening condition. Therapy must be carried out immediately. Various measures are taken to reduce the potassium concentration.
One of them is the administration of insulin. The application is either as an injection or as a continuous infusion. The infusion contains a precisely calculated amount of insulin and glucose.
Insulin causes glucose to be absorbed into the cells of the liver and skeletal muscles. At the same time, potassium is also transported into the cells and thus removed from the extracellular space. The administration of insulin alone would lead to hypoglycaemia if the blood sugar level is normally high.
For this reason, glucose is added to the infusion. However, this has no effect on the level of the potassium value. In general, blood sugar must be monitored at close intervals during the administration of insulin.
Insulin can be administered as a so-called bolus in the form of 10 to 20 IU (injection units) into the subcutaneous fatty tissue. Another possibility is intravenous administration via a continuous infusion. For example, 10 IU insulin is administered together with 100ml of a 33 percent glucose solution.
However, the exact dosage depends on the initial blood sugar level. After about 10 to 20 minutes, the first effects begin. The maximum effect is reached after about half an hour to a full hour and lasts for about five hours in decreasing intensity.
During this time, the potassium value can be reduced by a value of 0.5 to 1.5 mmol/l.The higher the value of the original potassium concentration and the higher the added insulin concentration, the clearer the therapeutic effect. Infusion with insulin is an efficient and rapid method of lowering serum potassium concentrations. Only dialysis achieves an even faster reduction.
