Effects of pre‐operative risk factors on intensive care unit length of stay (Icu‐los) in major oral and maxillofacial cancer surgery

Objective: This study aimed to investigate the effect of certain pre‐operative parameters directly on the post‐operative intensive care unit (ICU)‐length of stay (LOS), in order to identify at-risk patients that are expected to need prolonged intensive care management post‐operatively. Material and Methods: Retrospectively, patients managed in an ICU after undergoing major oral and maxillofacial surgery were analyzed. Inclusion criteria entailed: age 18–90 years, major primary oral cancer surgery including tumor resection, neck dissection and microvascular free flap reconstruction, minimum operation time of 8 h. Exclusion criteria were: benign/borderline tumors, primary radiation, other defect reconstruction than microvascular, treatment at other centers. Separate parameters used within the clinical routine were set in correlation with ICU‐LOS, by applying single testing calculations (t‐tests, variance analysis, correlation coefficients, effect sizes) and a valid univariate linear regression model. The primary outcome of interest was ICU‐LOS. Results: This study included a homogenous cohort of 122 patients. Mean surgery time was 11.4 (±2.2) h, mean ICU‐LOS was 3.6 (±2.6) days. Patients with pre‐operative renal dysfunction (p < 0.001), peripheral vascular disease‐PVD (p = 0.01), increasing heart failure‐NYHA stage categories (p = 0.009) and higher‐grade categories of post‐operative complications (p = 0.023) were identified as at‐risk patients for a significantly prolonged post‐operative ICU‐LOS. Conclusions: At‐risk patients are prone to need a significantly longer ICU‐LOS than others. These patients are those with pre‐operative severe renal dysfunction, PVD and/or high NYHA stage categories. Confounding parameters that contribute to a prolonged ICU‐LOS in combination with other variables were identified as higher age, prolonged operative time, chronic obstructive pulmonary disease, and intra‐operatively transfused blood.