Objective of the study: Delayed diagnosis of increased intra-abdominal pressure in PICU patients increases morbidity and mortality rates. In 2007 our PICU implemented a protocol for indirect intra-abdominal pressure (IAP) measurements by an indwelling bladder catheter using a pressure transducer. One of the indications to start IAP measurement is an increased abdominal distension. The aim of this study was to evaluate the effects of this protocol, including the nurses' compliance.