A mesenteric traction syndrome manifests in some patients undergoing major abdominal surgery and is identified by flushing, accompanied by hypotension and tachycardia. We used laser speckle contrast imaging to quantify blood flow in forehead skin of patients undergoing Whipple's operation. In two patients with similar blood pressure (-50 mmHg) and profound drop in systemic vascular resistance (-40%), forehead skin perfusion increased three-fold in one patient, while it was unchanged in a patient for whom flushing was not evident.