Preoperative total lymphocyte count was not associated with adverse postoperative events following elective shoulder arthroplasty

Background With the heightened focus on lowering adverse postoperative events through preoperative patient optimization, malnutrition may be a modifiable risk factor that could be addressed and lead to improved postoperative outcomes. However, an understanding of the association between malnutrition status and adverse postoperative events following shoulder arthroplasty is lacking. We sought to evaluate the association between preoperative malnutrition status, identified via the total serum lymphocyte count, and adverse postoperative events following shoulder arthroplasty. Methods We conducted a cohort study using data from Kaiser Permanente's Shoulder Arthroplasty Registry. Patients who underwent elective primary shoulder arthroplasty were identified (2005-2016). Patients with a preoperative total lymphocyte count Results The final study cohort comprised 6956 shoulder arthroplasty patients, with 2133 (30.7%) identified as malnourished. No difference in septic or aseptic revision risks was observed when comparing patients with and without malnutrition; however, malnourished patients had a higher risk for death, regardless of age ( Conclusion Only a higher mortality risk was observed to be associated with total lymphocyte count-defined malnutrition in patients undergoing elective shoulder arthroplasty. When instead looking at total lymphocyte count continuously, an optimal threshold for discriminating risk of adverse postoperative events could not be identified. Further study is needed to identify an appropriate indicator of malnutrition in shoulder arthroplasty patients and if this indicator can be modified to improve patient status and quality of care. Level of Evidence Level III; Retrospective Cohort Comparative Study