Point-of-care gastrointestinal and urinary tract sonography in daily evaluation of gastrointestinal dysfunction in critically ill patients (GUTS Protocol) - Perez-Calatayud, Angel; Carrillo-Esper, Raul; Anica-Malagon, Eduardo; Briones-Garduño, Jesus; Arch-Tirado, Emilio; Wise, Robert; Malbrain, Manu (Anestezjologia Intensywna Terapia, 2018)