Intraoperative Risk Factors Associated With Postoperative Pressure Ulcers in Critically Ill Patients: A Retrospective Observational Study

Objective: The risk for pressure ulcers is rarely identified in the perioperative period, and the influence of this period on risk factors has not been as rigorously studied as the postoperative period. We hypothesized that intraoperative risk factors exist, which increase the likelihood of a postoperative new-onset pressure ulcer. Design: A retrospective observational study. Setting: A large midwestern U.S. quaternary care institution. Patients: A total of 2,695 adult surgical patients underwent operative procedures and received care in one of three ICUs using an electronic documentation application. Interventions: None. Measurements and Main Results: The primary outcome was hospital-acquired pressure ulcer categorized as stages II, III, and IV; deep tissue injury; or unstageable. Univariate analyses comparing patients with and without the outcome of pressure ulcers were conducted for each preoperative characteristic or comorbidity. Patients were matched using the logit of the propensity score based solely on their preoperative comorbidities. Adjusted associations between development of pressure ulcers and intraoperative characteristics were determined in the postmatch cohort. We identified seven independent preoperative patients' characteristics and comorbidities in our adult surgical patient sample: American Society of Anesthesiologists risk classification 4 or 5, underweight body mass index, noncardiac surgery, history of congestive heart failure, renal disease, existing airway present prior to arrival in the operating room, and age. The only significant association in the matched dataset accounting for patient preoperative variability is the use of intraoperative blood products. Conclusion: Postoperative pressure ulcers developed in 10.7% of critically ill patients in our study. Only intraoperative use of blood products, not operative case length, hypotension, or vasopressor use, was associated with postoperative pressure ulcer development on adjusted analysis.