Administration of PiCCO

A central venous catheter (Arrow, Asheboro, NC, USA) was inserted in the subclavian vein, and was confirmed to be placed in the superior vena cava by bedside echo exam for analysis. The zero point was corrected and the CVP read. The PiCCO catheter (4F, PULSION, Feldkirchen, Germany) was placed via the femoral artery prior to connecting the monitor. The temperature probe was connected to the subclavian vein catheter. After the monitor was ready, mean arterial pressure (MAP), CI, GEDVI, and ITBVI were recorded. During measurement, 20 ml of saline in 4°C was injected quickly (within 5 s), measuring at least 3 times in a row, and using measurements whose variation was less than 15%.