Klinische beslisregels: Ervaringen met hyperkaliëmie, hyponatriëmie en doorgeschoten INR's

Objective: To describe our experience with three clinical rules, which were aimed at identifying patients with potentially drug-induced hyperkalaemia, hyponatraemia or elevated INR levels, respectively. Methods: The clinical rule 'hyperkalaemia' identified patients who were using potassium-sparing diuretics or potassium supplementation despite a recently measured high potassium level. The clinical rule 'hyponatraemia' identified patients who were using potentially sodium-lowering drugs despite a recent low sodium level. The clinical rule 'elevated INR' identified patients with a recently elevated INR who were using drugs that interact with oral anticoagulation therapy. The output of the three clinical rules was noted during a 2-month period (reference period). Afterwards, hospital pharmacists performed interventions based on the output of these rules during a 2-month period (test period). Results: Interventions based on the output of the clinical rules prevented patients with hyperkalaemia from being discharged from the hospital while still using drugs which are known to increase serum potassium levels. In addition, the implementation of clinical rules decreased the number of patients with hyponatraemia who used drugs which may lower sodium plasma levels. The clinical rule 'elevated INR' identified a few patients, for whom it was generally difficult to switch from the potentially interacting drug. A limitation of our clinical rules was their low specificity, i.e., the high number of false-positive signals. Conclusions: The implementation of clinical rules may improve the safe use of drugs, but it is necessary to improve specificity.