Association of preoperative plasma suPAR levels with intraoperative sublingual microvascular perfusion in patients undergoing major non-cardiac surgery

Abstract

Introduction: The plasma suPAR level has previously been associated with postoperative complications and has been shown to be an independent predictor of coronary microvascular function and flow reserve. We investigated the association between preoperative suPAR levels and intraoperative sublingual microvascular perfusion in patients undergoing elective major non-cardiac surgery. Methods: This study included 100 patients undergoing major non-cardiac surgery between February 2019 and September 2020. The primary objective was to investigate the association between preoperative suPAR and intraoperative sublingual De Backer score, Consensus Proportion of Perfused Vessels (Consensus PPV), and Consensus PPV (small). Secondary objectives were to investigate the associations between these sublingual microcirculatory variables and (1) complications and (2) mean arterial pressure. EDTA blood was collected before induction of anesthesia and plasma suPAR levels were determined using the suPARnostic quick triage lateral flow assay. Sublingual microcirculation was monitored with Sidestream DarkField (SDF+) imaging technique at 20 minutes after induction of anesthesia before surgical incision (baseline) and then every 30 minutes until emergence from anesthesia. Results: A decrease of 0.7 mm-1 in the De Backer score, 2.5% in the Consensus PPV, and 2.8% in the Consensus PPV (small) from baseline measurement was observed for every 1 ng/ml increase of suPAR or 1 additional minute of intraoperative time. De Baker score did not change significantly from baseline (p=0.404), while Consensus PPV and Consensus PPV (small) decreased significantly from baseline (p<0.001 in both cases). The De Backer score, the Consensus PPV, and the Consensus PPV (small) correlated with postoperative complications. Mean arterial pressure correlated with De Backer score (p=0.487) but not with Consensus PPV (p=0.506) or Consensus PPV (small) (p=0.697) during the intraoperative period. Conclusion: Preoperative suPAR levels and prolonged operative duration were associated with intraoperative impairment of sublingual microvascular perfusion in patients undergoing elective major non-cardiac surgery.