Perioperative hemoglobin trajectories and transient hemodilution during cytoreductive surgery with hyperthermic...

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal malignancies involves heated intraperitoneal cisplatin perfusion and liberal intravenous hydration, both of which may affect perioperative hemoglobin (Hb) concentrations. This study aimed to characterize Hb trajectories during HIPEC and determine whether these patterns differ between laparoscopic and open procedures. We retrospectively analyzed 186 HIPEC procedures performed between 2018 and 2023, including 107 laparoscopic and 79 laparotomy cases. Hb concentrations were assessed before HIPEC, from HIPEC initiation to the end of surgery, and on the first postoperative measurement. Changes were compared using two-way repeated-measures analysis of variance (ANOVA), and mixed-effects multivariable regression was used to identify factors associated with intra-to-postoperative Hb shifts. Laparoscopic procedures were shorter and associated with lower fluid administration and blood loss than laparotomy procedures (all p<0.001). Hb declined from baseline to intraoperative nadir in both groups, with reductions of -1.24 g/dL after laparoscopy and -1.62 g/dL after laparotomy (both p<0.001), followed by partial postoperative recovery of +0.84 g/dL and +0.62 g/dL, respectively (both p<0.001). Longer operative duration was associated with reduced postoperative Hb recovery in laparotomy cases (-0.12 g/dL/hour; p<0.040). HIPEC is associated with a modest intraoperative Hb decline followed by early partial recovery, a pattern consistent with transient intraprocedural hemodilution. Recognizing this trajectory may help contextualize intraoperative Hb values and support more nuanced transfusion decision-making.