Techniques of paediatric modified ultrafiltration: 1996 survey results

In September 1996, perfusionists from 50 paediatric open-heart surgery programmes were contacted to identify centres that are currently using the technique of modified ultrafiltration (MUF). Of the 50 centres contacted, 22 (44%) were utilizing the technique. These centres were surveyed on the following: neonatal circuit description, patient entry criteria, MUF circuit description, conduct of MUF, use of extracorporeal safety devices and/or modifications, and technical complications. All 22 centres used roller pumps and membrane oxygenators. In 19 centres, MUF was utilized exclusively in the arteriovenous mode (86%), while two centres (9%) used the venovenous mode and one centre (5%) used both methods. Most (82%) of the 22 MUF centres used a blood cardioplegia system for myocardial preservation. After cardiopulmonary bypass (CPB), these blood cardioplegia systems were often converted for use as MUF circuits in a variety of ways. Other methods of accessing the CPB circuit for MUF included utilizing either a recirculation line or a dedicated port added to the circuit specifically for MUF. Blood flow rates during MUF, pump strategies, haemoconcentrator vacuum levels and endpoints were variable from centre to centre. Technical complications related to MUF were reported by 82% of the surveyed MUF centres. The most common complication, air cavitating into the circuit, was reported by 15 centres. From these data, we propose recommendations on the integration of MUF into CPB circuits, the conduct of perfusion during MUF, and appropriate safety considerations to minimize technical complications.