Neonatal percutaneous central venous lines: fit to burst

To examine pressure changes in neonatal percutaneous central venous catheters under varying laboratory conditions and to quantify the risks of rupture in clinical practice.

We tested 27-gauge polyurethane Premicath and 24-gauge silicone ECC (both Vygon, Norristown, PA) catheters. Burst pressures were determined by applying a slowly ramped pressure to catheters that were occluded at the tip. Flow-pressure relationships were defined by increasing flow rates through patent catheters from 5 to 499 ml/h. Pressure changes during the manual flushing of catheters were determined for patent and occluded catheters and with different syringe sizes.

The mean burst pressure for polyurethane catheters (1730.8 kPa, 95% CI 1634.7 to 1826.8) was higher than for silicone catheters (275.6 kPa, 95% CI 240.4 to 310.8). Polyurethane catheters demonstrated an approximately fivefold greater margin of safety above manufacturer recommended operating pressures before burst compared to silicone catheters. Pressures remained at safe levels in both catheters over the range of flows generally used in neonatal practice. Hand-flushing of obstructed silicone catheters caused rupture in 5/6 silicone catheters tested, in comparison to 0/16 polyurethane catheters.

Polyurethane central venous catheters have a greater pressure tolerance than silicone catheters and are less likely to rupture under experimental conditions. Obstructed silicone catheters rupture easily when flushed. Catheters were not tested in human infants.