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

BACKGROUND: Continuous and minimally invasive near-infrared spectroscopy (NIRS)-derived gastric tissue oxygen saturation (GStO(2)) and muscle tissue oxygen 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 catheter insertion for mixed venous oxygen saturation (SvO(2)) measurement and midline laparotomy to permit placement of a gastric NIRS probe, a jejunal (regional carbon dioxide [PrCO(2)]) tonometer, superior mesenteric artery (SMA) flow probe, and a portal vein oxygen saturation (SpvO(2)) catheter. A muscle NIRS probe was placed on the front limb. After randomization, Group 1 underwent hemorrhage and resuscitation. Group 2 had no hemorrhage or resuscitation. ACS was induced by peritoneal fluid infusion in both groups. A significant decrease in SMA flow, SpvO(2), GStO(2), SvO(2), and MStO(2) was observed after hemorrhage in Group 1 and with abdominal hypertension in both groups. 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 systemic oxygen delivery (SDO2, Group 1: r(2) = 0.60; Group 2: r(2) = 0.88). Tonometer-derived PrCO(2) values did not change at any time point in either group. CONCLUSIONS: NIRS measurement of GStO(2) and MStO(2) reflected changes in mesenteric and systemic perfusion respectively during hemorrhage and ACS.

Utility of near-infrared spectroscopy in the diagnosis of lower extremity compartment syndrome.

OBJECTIVE: To determine the utility of near-infrared spectroscopy in the diagnosis of lower extremity compartment syndrome (CS). METHODS: Nine patients with CS confirmed by physical examination and elevated compartment pressures (64 +/- 17 mm Hg) were evaluated before and after fasciotomy. Control readings were also performed on 33 surgical patients who had no evidence of CS. The deltoid muscle was used as a reference value. RESULTS: The deltoid muscle oxygen saturation (StO2) readings revealed a mean = 84 +/- 17% prefasciotomy and mean = 83 +/- 12% postfasciotomy in the CS group. The control group had a mean StO2 of 83 +/- 11%. In the CS group, the leg compartment with the highest pressure had a StO2 mean = 56 +/- 27% before fasciotomy. This value was statistically significantly lower (p < 0.05) than either the postfasciotomy mean StO2 in that compartment (82 +/- 16%) or the values found in matched control patients with no evidence of CS (87 +/- 7%). CONCLUSION: Near-infrared spectroscopy-derived StO2 values in the lower extremities of trauma patients with CS were diminished relative to the control patients and usually normalized after fasciotomy. Near-infrared spectroscopy evaluation may offer a rapid, noninvasive method of assessing extremities at risk for CS.