Congenital heart defects, perioperative manegement results in 18 months. Experience of the Maternal and Child Center Cardiosurgery Section Introduction: Survival of patients with congenital heart defects has improved in recent years thanks to improved diagnostic, surgical, anesthetic, and extracorporeal circulation techniques, and the arrival of new and more selective cardioactive drugs. Objectives: To describe perioperative care and postoperative progress of patients following surgery performed in the department of cardiac surgery and pediatrics department of the Centro Materno Infantil (CMI) of the National University's School of Medical Sciences over a period of 18 months, and its relationship to the type of surgery performed (elective or emergency) and the patient's presurgical physical status classifi cation of the American Society of Anesthesiologists (ASA-PS). Materials and Methods: A retrospective, descriptive, observational study with an analytical component using the medical records of patients operated on in the department of cardiac surgery between January 2007 and June 2008. Results: Of the 91 patients undergoing surgery, 38 (42%) were male, and 53 (58%) were female, with ages ranging from 2 days to 18 years. Uncomplicated heart disease was found in 54 patients (59.3%), and complications con-fi rmed by color Doppler echocardiography were found in 37 (40.7%). Cardiac catheters were needed before surgery by 3 patients (3.3%). All surgeries (100%) were performed under balanced general anesthesia. Of the 91 patients operated on, 42 (46.2%) received extracorporeal circulation (ECC) and 49 (53.8%) did not. Of the 42 patients who received ECC, all involved corrective surgery, with 40 (96.2%) of those being elective, and 2 (4.8%) emergency surgery, while 3 (7.1%) were reoperated and 2 (4.8%) died. Complications appeared in 16 patients (38.1%), with 39 (92.9%) requiring mechanically assisted ventilation (MAV) for less than 24 hours, and 3 (7.1%) who received MAV for more than 24 hours. Aortic clamping time ranged from 13 to 167 minutes (mean 49.1 min) and ECC times from 20 to 253 minutes (mean 71.9 min). Plasma ultrafi ltration (pUF) was done in all (100%) of patients operated on who received ECC, all of whom also received prophylactic aprotinin for bleeding. Of the 49 patients operated on without ECC, 30 (61.2%) were corrective surgeries, 19 (38.8%) were palliative, 31 (63.3%) were elective, 18 (36.7%) were emergency surgery, 1 (2.1%) was a reoperation, and 10 (16.3%) died. Complications appeared in 18 patients (36.7%), with 39 (79.6%) requiring MAV for less than 24 hours, and 10 (20.4%) receiving MAV for more than 24 hours. Of the patients operated on, 34 developed complications, 28% in elective surgeries and 65% in emergency surgeries; by type these were 50% were hemodynamic; 35.3% respiratory, 23.5% neurological, 14.7% infectious, 14.7% metabolic, 11.8% hema-tological, and 11.8% renal. Conclusions: Morbidity and mortality were directly related to two factors: being emergency surgery, and the presurgical physical status classifi cation of the patient as per the ASA-PS. There were no deaths in the elective surgeries, and the patients who died had an ASA 4 preoperative physical status classifi cation. Intraoperative use of pUF and aprotinin contributed to the favorable progress of the patients operated on with use of ECC.