Williams Syndrome and Anesthesia for Non-cardiac Surgery: High Risk Can Be Mitigated with Appropriate Planning

Patients with Williams syndrome are considered at high risk for anesthesia-related adverse events. At our institution, all William syndrome patients undergoing cardiac surgical, cardiac catheterization/interventional procedures, and cardiac imaging studies are cared for by cardiac anesthesiologists. All William syndrome patients undergoing non-cardiac surgical, interventional, or imaging studies are cared for by main operating room pediatric anesthesiologists with consultative input from a cardiac anesthesiologist. We reviewed our experience with 75 patients undergoing 202 separate anesthetics for 95 non-cardiac procedures and 107 cardiac procedures from 2012 to 2016. The mean age was 7.5 ± 7.0 years and the mean weight was 22.3 ± 17.0 kg. One hundred and eighty-seven patients had a general anesthetic (92.6%). Medications used included etomidate in 26.2%, propofol in 37.6%, isoflurane in 47.5%, and sevoflurane in 68.3%. Vasopressors and inotropes were required including calcium (22.8%), dopamine (10.4%), norepinephrine (17.3%), phenylephrine (35.1%), vasopressin (0.5%), and ephedrine (5.4%). The median length of stay after anesthesia was 2.8 days (range 0-32). No adverse events occurred in 89.6% of anesthetics. There were two cases of cardiac arrest, one of which required extracorporeal life support for resuscitation. Of the non-cardiac surgical procedures, 95.7% did not have a cardiovascular adverse event. Patients with Williams syndrome are at high risk for anesthesia, especially when undergoing cardiac procedures. The risk can be mitigated with appropriate planning and adherence to the hemodynamic goals for non-cardiac surgical procedures.