The following should be monitored frequently (as often as hourly): Volume status using central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), serial ultrasound and / or central venous oxygenation saturation (ScvO2) Arterial blood gases (ABGs) Blood glucose, lactate, and electrolyte levels Renal function Arterial oxygen saturation should be measured continuously via pulse oximetry.