exceeds certain level, but what is the cutoff level exceeding which we will absolutely cancel the surgery? What if the surgery is for the establishment of dialysis for the purpose of lowering potassium level?Dr. Douglas Slakey's study found that 39% medical professionals in their institution believe a serum potassium level ≥ 6 mEq/L is clinically significant hyperkalemia while 47% believe 5.6-5.9 mEq/L is clinically significant. Only half of their practicing medical professionals recognized that Renin-angiotensin-aldosterone system inhibitor is a risk factor for hyperkalemia. The authors analyzed 645,073 surgical cases in their health system, 9,166 (1.4%) had preoperative hyperkalemia. And they also found that African American and Hispanic patients were significantly more likely to have preoperative hyperkalemia (≥ 6.0 mEq/L) when compared to White patients. Additionally, they unveiled patients with a potassium level ≥ 6.0 mEq/L within 24 hours will have significantly higher probability (2.40 times) to gettheir surgery cancelled when compared to patients with a potassium level at 5.1-5.9 mEq/L. Zaki, et al. reported that patients with a serum potassium level over 5.5 mEq/L were twice likely to require intraoperative management to lower potassium level when compared to patients with a potassium level ≤ 5.5 mEq/L [4].Should potassium level 5.5 or 6.0, or even 6.5 mEq/L be the cut-off criteria? Any subset patients maybe be reasonably safe even with potassium level at 6.5 mEq/L? What if the patient does not have dialysis avenue and the surgery is scheduled to establish one?There is no consensus in dealing with these patients with perioperative hyperkalemia by medical professionals even in the same department and same institution. We need an evidence-based hyperkalemia guideline badly! What Should be Included in the Evidence-Based Guideline for Hyperkalemia Management?1. A generally accepted cutoff level of preoperative serum potassium.