Plasma levels of potassium and magnessium after modified ultrafiltration in pediatric cardiac surgery with cardiopulmonary bypass

Abstract

Objective: Modified ultrafiltration (MUF) reduces some of the complications associated with cardiopulmonary bypass (CPB) in pediatric cardiac surgery. However, we have observed hypokalemia and hypomagnesemia in children when MUF is used. Such alterations may elicit severe arrhythmias in the postoperative period. To date, no studies have focused on the effects MUF may have in plasma levels of potassium (K) and magnesium (Mg). The objective of our study was to determine if there is any variation in plasma levels of K (plK) and Mg (plMg) after MUF in children undergoing cardiac surgery with CPB.

Patients: Sixteen children scheduled for cardiac surgery with CBP and MUF were prospectively studied. Anesthetic, CPB and MUF management were standardized for all patients, the latter lasting for 10 minutes.

Results: Plasma K average levels before and after MUF were 4.16 mmol/L and 3.58 mmol/L, respectively. The average plasma Mg levels before and after MUF were 4.82 mmol/L and 4.81 mmol/L, respectively.

Conclusions: The plasma level of K is reduced by 13.7% after MUF (p<0.0001). The reduction in Mg at the same period of time was not statistically significant (p<0.970).