Impaired tissue perfusion in high-risk patients having major abdominal surgery: a multicenter observational study

Surgical trauma may cause systemic inflammation and impaired tissue perfusion. However, the incidence of signs of impaired tissue perfusion in patients undergoing major abdominal surgery remains largely unknown. This study investigated the incidence of signs of impaired tissue perfusion – specifically capillary refill time, mottling score, lactate, and central venous oxygen saturation – in high-risk patients having major abdominal surgery. This multicenter prospective observational study included 291 high-risk patients undergoing major abdominal surgery at 5 university hospitals in Germany. Signs of impaired tissue perfusion were measured until the first postoperative day and defined as a capillary refill time of ≥ 3 s, mottling score of ≥ 1, lactate of ≥ 2 mmol/L, or central venous oxygen saturation of ≤ 65%. The primary endpoint was the proportion of patients with signs of impaired tissue perfusion until the first postoperative day. Overall, 171 patients (59%) demonstrated signs of impaired tissue perfusion at any postoperative time point. Specifically, capillary refill time was prolonged in 19 patients (7%), mottling score was elevated in 43 patients (15%), lactate levels were elevated in 73 patients (25%), and central venous oxygen saturation was low in 119 patients (41%). At each time point, the majority of patients exhibited only a single sign of impaired tissue perfusion. No meaningful differences in macrocirculation variables were observed between patients with and without signs of impaired tissue perfusion. The presence of any postoperative sign of impaired tissue perfusion was weakly associated with longer intensive care unit length of stay (P = 0.012), but not meaningfully with the highest SOFA score on postoperative days 1, 3, or 5, hospital length of stay, and 28-day mortality. Approximately 60% of high-risk patients undergoing major abdominal surgery demonstrated postoperative signs of impaired tissue perfusion, although most patients exhibited only one sign. Whether these signs of impaired tissue perfusion are clinically meaningful requires further investigation in larger studies. German Clinical Trials Register (DRKS00020264) on January 10, 2020.