Intestinal blood flow and pCO₂ gradients in arterial and venous mesenteric blood flow obstruction

Introduction

In this study, we evaluated the systemic and regional pCO₂ gradients changes induced by arterial and venous mesenteric blood flow obstruction. In addition, we sought to obtain evidence that systemic markers of splanchnic hypoperfusion can detect the initial changes after intestinal ischemia induced by arterial or venous blood flow interruption.

Methods

Fourteen dogs were subjected to 45 min of superior mesenteric artery (SMA-O, n = 7) or vein occlusion (SMV-O, n = 7). Systemic hemodynamic was evaluated through a Swan–Ganz catheter and arterial catheters, while gastrointestinal tract perfusion was evaluated by superior mesenteric vein and serosal blood flows (SMVBF and SBF, ultrasonic flowprobe). Intestinal O₂-derived variables, mesenteric–arterial and tonometric–arterial pCO₂ gradients (D_mv-apCO₂ and D_t-apCO₂) were calculated.

Results

A significant decrease in CO and MAP was detected in the SMV-O group; pCO₂ gradients presented a significant increase in both groups (Fig. 1). The histopathologic injury scores were 2.7 ± 0.5 and 4.8 ± 0.2 for the SMA-O and SMV-O groups, respectively.

Figure 1

Conclusion

Temporary mesenteric congestion was associated with significant hemodynamic and metabolic disturbances. The D_t-apCO₂ changes can be detected by systemic markers of splanchnic hypoperfusion after temporary SMV occlusion.