Development and validation of a nomogram for newly developed lower extremity deep vein thrombosis in early postoperative critically ill patients: A prospective cohort study

Objective: Establishing a nomogram to estimate the incidence of early postoperative lower extremity deep vein thrombosis in critically ill patients and to explore the risk factors associated with deep vein thrombosis. Method: We performed binary logistic regression analysis on demographic, anesthesia, surgical, and laboratory data from 511 patients transferred to the surgical intensive care unit (SICU) within 12 hours post-surgery at West China Hospital. The associated risk factors were analyzed to construct a nomogram. Validation was then conducted on 169 ICU patients who were also transferred to the SICU within 12 hours post-surgery, with their associated risk factors analyzed. Results: The incidence of newly developed lower extremity deep vein thrombosis in surgical intensive care unit patients after surgery was found to be 30.14%, with all instances specifically involving calf intermuscular venous thrombosis. Seven variables emerged as independent predictors, integrated into the nomogram: intraoperative hypothermia, surgery time, intraoperative bleeding volume≥ 500 ml , last last c-reactive protein before surgery , intraoperative hypotension, use of norepinephrine during surgery , and last D-dimer before surgery. Conclusion: The nomogram we developed can assist clinicians in better identifying at-risk patients and risk factors. It enables the implementationof evidence-based nursing interventions in care to reduce the incidence of lower extremity deep vein thrombosis and thereby improve patients' postoperative recovery and overall prognosis.