Objective evaluation of facial flushing for mesenteric traction syndrome diagnosis during laparotomy: a prospective observational pilot study

We aimed to evaluate the concordance between facial flushing assessment using an objective color sensor and subjective visual assessment in patients with mesenteric traction syndrome (MTS), to inform the design of a future large-scale study that incorporates objective diagnostic tools. In this prospective pilot study, we enrolled adult patients who underwent pancreatectomy. Anesthesiologists assessed the degree of facial flushing subjectively using a scale of levels 0–2. Simultaneously, the Nix color sensor objectively measured the facial redness (a-value) at four facial points. Heart rate and arterial blood pressure were also recorded. Based on the anesthesiologist’s diagnosis, patients were categorized into either the MTS or non-MTS group. We compared the ratio of changes in a-value, heart rate, and blood pressure between the two groups, and their thresholds were also calculated. We included 38 patients: 14 in the MTS group and 24 in the non-MTS group. The MTS group showed significantly higher median change ratio in a-value (0.45 vs. 0.25, P = 0.02) and heart rate (0.45 vs. 0.23, P < 0.01) and a greater decrease in mean arterial pressure (-0.26 vs. -0.14, P = 0.01) than the non-MTS group. Subjective flushing levels correlated with MTS diagnosis (P < 0.01). While the Nix sensor detected flushing in some subjectively undiagnosed cases, one patient in the non-MTS group met all three objective thresholds. Objective evaluation of facial flushing using a color sensor is feasible and may enhance conventional assessment methods. To further improve the accuracy of objective evaluation, this pilot study may lead to a larger-scale study including blood tests.