*1.4.1 Potassium*

The serum potassium levels in patients with chronic renal or end-stage renal disease are typically elevated. Hyperkalemia is potentially life-threatening and must not be neglected. There are no "cut off" levels of preoperative potassium levels to consider for canceling the case or proceeding the procedure safely. Therefore, the potassium level used to determine "go or not go" may vary among hospitals. It should be noted that the serum potassium level is closely related to serum pH. Therefore, if the patient is acidotic, re-evaluation of serum potassium level must be considered after serum pH is corrected. In our institution, a potassium level higher than 6.0 mmol/L prompts a discussion between the anesthesia and surgical teams regarding the need for urgent hemodialysis prior to the procedure. One additional consideration is that venous potassium levels can sometimes falsely be higher than arterial levels. Obtaining and checking an arterial blood sample may be useful in confirming the correct true potassium level [2]. Occasionally, patients can have a lower preoperative potassium

#### *Anesthetic Management of Surgical Vascular Access for Hemodialysis DOI: http://dx.doi.org/10.5772/intechopen.109844*

level (<3.5 mmol/L). Hypokalemia is not as dangerous for patients as hyperkalemia. Therefore, correction is required if it is associated with frequent cardiac arrhythmias or with significant EKG changes such as QT prolongation. It is extremely difficult to correct hypokalemia in a patient with ESRD. Therefore, consultation with a nephrologist or a cardiologist is safer to avoid overcorrection with possible cardiac complications.
