Rebound hyperkalemia after cessation of ritodrine in a parturient undergoing cesarean section.

A 36-year-old parturient with a suspicion of placenta accreta under tocolytic therapy with ritodrine infusion underwent emergency cesarean section under general anesthesia with propofol, ketamine, and remifentanil because massive bleeding was anticipated. The ritodrine infusion was discontinued 1 h before cesarean section. The baby was delivered 6 min after induction of anesthesia. However, after the manual removal of the placenta from the uterus, the bleeding was massive and uncontrollable. We rapidly transfused crystalloid, colloid, and red blood cells through potassium removal filter. Hyperkalemia (5.8 mmol/L) was detected just before blood transfusion. One hour later, hemostasis was still difficult, and hyperkalemia was promoted (6.1 mmol/L). Thus, glucose insulin therapy started with intravenous furosemide to treat hyperkalemia. Gynecologists decided to induce the Bakri balloon tamponade for the treatment of postpartum hemorrhage. At the end of surgery, plasma potassium level also reduced to 5.5 mmol/L. In the ICU, the bleeding still continued, and then radiologists performed bilateral internal iliac artery embolization for full hemostasis. Postoperative plasma potassium level was stable and 3.3 mmol/L in the next morning. Although one of the common adverse reactions of ritodrine is hypokalemia, we should also beware of a rebound hyperkalemia after its cessation.