Near-infrared spectroscopy reflects changes in mesenteric and systemic perfusion during abdominal compartment syndrome

Background. Continuous and minimally invasive near-infrared spectroscopy (N IRS)-derived gastric tissue oxygen saturation (GStO(2)) and muscle tissue o xygen saturation (MStO(2)) were evaluated in a clinically relevant porcine model of hemorrhagic shock and abdominal compartment syndrome (ACS). Methods, Phenobarbital-anesthetized swine underwent pulmonary artery cathet er insertion for mixed venous oxygen saturation (SvO(2)) measurement and mi dline laparotomy to permit placement of a gastric NIRS probe, a jejunal (re gional carbon dioxide [PrCO2]) tonometer superior mesenteric artery (SiMA) flow probe, and a portal vein oxygen saturation (SpvO(2)) catheter. A muscl e MRS probe was placed on the front limb. After randomization, Group 1 unde rwent hemorrhage and resuscitation, Group 2 had no hemorrhage or res resusc itation. ACS was induced by peritoneal fluid infusion in both groups. A sig nificant decrease in SMA flow, SpvO(2), GStO(2), SvO(2) and MStO(2) was obs erved after hemorrhage in Group 1 and with abdominal hypertension in both g roups. Results. GStO(2) significantly correlated with SMA flow (Group 1: r(2) = 0. 90; Group 2: r(2) = 0.83) and mesenteric oxygen delivery (mesenteric oxygen delivery, Group 1: r(2) = 0.73 Group 2. r(2) = 0.89. MStO(2) significantly correlated with SvO(2) (Group 1: r(2) = 0.99; Group 2: r(2) = 0.65 )and sy stemic oxygen delivery (SDO2, Group 1: r(2) = 0.60; Group 2: r(2) = 0.88). Tonometer-derived PrCO2 values did not change at any time point in either g roup. Conclusions. NIRS measurement of GStO(2) and MStO(2) reflected changes in m esenteric and systemic per fusion respectively during hemorrhage and ACS.