Study: Postoperative potassium risk overstated for cardiac bypass patients

Editor's Note

The common practice of administering potassium after bypass surgery can be safely abandoned in patients with normal blood levels, according to results of the randomized TIGHT-K trial.

According to a September 3 report in Medscape, potassium supplementation is a widely accepted means of reducing the risk of postoperative atrial fibrillation in cardiac bypass patients. In fact, atrial fibrillation occurs in about one third of bypass surgery patients. However, the researchers claim evidence supporting the post-operative potassium supplementation is lacking. 

Involving 1,690 participants across 23 centers in Germany and the United Kingdom, the trial was presented at European Society of Cardiology (ESC) Congress.

It assessed two levels of potassium supplementation: a tight-control group in which supplementation maintained high-normal potassium levels (> 4.5 mEq/L), and a relaxed-control group that took potassium only when levels dipped below low-normal (< 3.6 mEq/L), Medscape reports. Rates of new-onset atrial fibrillation within 5 days of bypass surgery were similar for both groups, as were rates of dysrhythmias other than atrial fibrillation as well as secondary endpoints, such as length of hospital stay.

However, cost was approximately $120 lower per patient in the relaxed-control group than in the tight-control group. Overall, avoiding potassium supplementation can reduce costs and decrease risks posed to patients by unnecessary intervention.

The full report provides additional context on the study, including applicability beyond coronary artery bypass graft procedures, details on potassium supplementation, and research into alternative methods for reducing risks of post-operative complications.