Usefulness of external counterpulsation early postoperatively after the Fontan procedure in children

temic venous return, and reduces ventricular afterload. 1‐3 We hypothesized that EC could benefit patients who underwent the Fontan procedure by improving cardiac output in the early postoperative period. EC had not been studied in the postoperative setting, and had never previously performed in the pediatric population. Therefore, this investigation sought to provide preliminary evidence of EC safety and short-term efficacy in children after Fontan surgery. ••• We performed a prospective, within-patient, controlled investigation of EC in children who underwent the Fontan procedure (fenestrated and nonfenestrated) at Children’ s Medical Center, Dallas, from May 1999 to June 2001. Children were considered for participation in the study if they were consecutive pediatric patients for whom parental consent was obtained, if there was an EC machine available, and if EC cuff sizes were deemed appropriate (pediatric-sized cuff straps able to be tightened over a sheepskin barrier to prevent excessive movement and skin irritation during EC). Patients were excluded from study for the following reasons: significant intraoperative surgical complications that may have compromised postoperative neurologic status (defined as 10 minutes of hypotension off bypass with blood pressure less than the fifth percentile for age), extubation before or immediately upon arrival to the cardiac intensive care unit, presence of a cardiac arrhythmia or paced heart rhythm, invasive line(s) in the femoral or lower extremities, peripheral vascular disease, musculoskeletal anomaly involving the lower extremities, significant and prolonged postoperative hemorrhage (3 ml/kg/ hour persisting for 10 hours after arrival to the cardiac intensive care unit), or aortic insuf ficiency. After admission to the cardiac intensive care unit, each patient was assessed for clinical stability. Blood products and/or volume (5% albumin) were administered and inotropes were adjusted at the discretion of the attending physician based on hemodynamic status, chest tube drainage, hemoglobin level, and degree of anticoagulation. Intravenous fluid was administered before the investigation if systemic perfusion was determined to be clinically poor, or if systolic blood pressure decreased below the fifth percentile for age at any time. The study protocol was initiated while patients were sedated and anesthetized with midazolam and fentanyl, before extubation, and after mediastinal blood loss was controlled (3 ml/kg/hour). Inotropes and vasoactive medications were unchanged during the period of investigation. The study protocol was divided into 3 10-minute periods. During the first period, baseline parameters were measured before initiation of EC. This was immediately followed by a 10-minute EC period, and directly thereafter, a postintervention period. The hemodynamic parameters obtained during all 3 periods included cardiac index (CI) by ascending aortic pulse Doppler echocardiography (averaged over 8 cardiac cycles), 4 vital signs (heart rate, blood pressure), and central venous pressure (CVP). Each parameter was measured every minute during the 3 study intervals, except ascending aortic Doppler flow, which was evaluated every 2 minutes. Echocardiographic determinations of CI were made off-line by a single interpreter who was blinded to the period of testing. Blinded interpretation was feasible because EC does not alter ascending aortic Doppler flow patterns.5 Chest tube output and oxygen saturation were recorded throughout the investigation. EC was performed using the Cardiomedics Cardi