BRIEF COMMUNICATION Intraoperative Blood Pressure Lability Is Associated with Postoperative Hemorrhage after Uncomplicated Bariatric Surgery Lee D. Ying 1 & Andrew J. Duffy 1,2 & Kurt E. Roberts 1,2 & Saber Ghiassi 1,2 & Matthew O. Hubbard 1,2 & Geoffrey S. Nadzam 1,2 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Background Postoperative hemorrhage is a rare complication in bariatric surgery. We aim to determine if differences in blood pressure or perioperative medication administration contribute to postoperative bleeding in patients who were hemodynamically stable intraoperatively. Methods This was a retrospective case-control study of all bariatric surgery patients from 2014 to 2017 at a high volume academic center. We identified controls based on age, gender, ethnicity, type of procedure, and pre-operative blood pressure. Results Patients with postoperative hemorrhage had a significantly lower MAP during the portion of the surgery in which the abdominal contents were inspected for leaks and bleeds. The timing of enoxaparin or ketorolac administration was not associated with bleeding. Conclusion Blood pressure lability, but not enoxaparin or ketorolac administration, is associated with postoperative hemorrhage. Keywords Bariatric surgery . Postoperative hemorrhage . Blood pressure lability . Anticoagulation Introduction Bariatric surgery is a very safe procedure with complication rates on par with gallbladder surgery or hip replacement [1], but it is not without risk. One complication that has received increasing attention is postoperative hemorrhage, which occurs in approximately 3% of all cases [2] and is defined in this study as Bbleeding after surgery resulting in a hematocrit drop and leading to patients receiving a blood transfusion. ^ Postoperative hemorrhage is especially challenging when it oc- curs after uncomplicated cases completed with minimal blood loss. Many factors could increase the risk of postoperative bleeding, and in this study, we examined the role of periopera- tive blood pressure status and postoperative medication use. Blood pressure status is frequently assessed in the context of postoperative hemorrhage [3, 4], and many studies report that postoperative hypertension is associated with increased risk of bleeding [5]. A retrospective case-control study conducted by Janik et al. found that bariatric surgery patients with hemorrhagic complications had decreased postoperative systolic blood pres- sure, although their results were not statistically significant. The contribution of perioperative medications such as enoxaparin and ketorolac to postoperative hemorrhage has been studied [6, 7], but whether the timing of their administration affects postop- erative bleeding in bariatric surgery is unclear. In this retrospec- tive nested case-control analysis, we attempt to determine wheth- er perioperative blood pressure lability or perioperative medica- tion use is associated with postoperative hemorrhage. * Lee D. Ying Lee.Ying@Yale.edu Andrew J. Duffy Andrew.Duffy@Yale.edu Kurt E. Roberts Kurt.Roberts@Yale.edu Saber Ghiassi Saber.Ghiassi@Yale.edu Matthew O. Hubbard Matthew.Hubbard@Yale.edu Geoffrey S. Nadzam Geoffrey.Nadzam@Yale.edu 1 Yale School of Medicine, New Haven, CT, USA 2 Department of Gastrointestinal Surgery, Yale Medicine, New Haven, CT, USA Obesity Surgery https://doi.org/10.1007/s11695-019-03839-y