Inflammatory cell indexes as preoperative predictors of hospital stay in open elective thoracic surgery

Background: Shorter and safer hospital stay (HS) is a desired outcome for patients undergoing thoracic surgery. The aim of the present study was to evaluate the predictive capacity of a series of pre-defined inflammatory cell indexes based on preoperative complete blood counts, towards length of HS in open elective thoracic surgery. Methods: We retrospectively studied 157 consecutive patients undergoing open elective thoracic surgery. Preoperative neutrophil to lymphocyte, platelet to lymphocyte and lymphocyte to monocyte ratios were calculated, and the red cell distribution width and mean platelet volume were registered. In addition, the systemic inflammation response index (SIRI) and a further derivative index, the aggregate inflammation systemic index (AISI) were calculated. Results: Statistically significant and positive correlations were observed between HS and SIRI, and between HS and AISI. In multiple logistic regression analysis, after dividing the patients in groups with normal and prolonged HS and adjusting for several confounders, only AISI was independently associated with HS. Conclusions: Our results suggest that simple, inexpensive and widely available inflammatory cell indexes like SIRI and, particularly AISI, can be useful for the early identification of patients at risk of prolonged HS in open elective thoracic surgery.