5PSQ-080 Cisplatin-induced nephrotoxicity and electrolyte imbalances in hyperthermic intraperitoneal chemotherapy (HIPEC)

<h3>Background and Importance</h3> Hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin during cytoreductive surgery (CRS) offers survival benefits in peritoneal carcinomatosis. However, cisplatin is associated with significant renal toxicity. In patients undergoing HIPEC, the prevalence of postoperative acute kidney injury (AKI) can be as high as 48%. Prophylactic treatment with sodium thiosulfate (ST) can be effective to avoid this complication, but evidence seems weak. Additionally, cisplatin can cause electrolyte imbalances. <h3>Aim and Objectives</h3> To evaluate the renal toxicity of HIPEC with cisplatin while using ST as prophylaxis, as well as the possible alterations in serum potassium and sodium levels caused by the procedure. <h3>Material and Methods</h3> We conducted a retrospective observational study, which included demographic and clinical data of patients treated with HIPEC with cisplatin from January 2023 to June 2024 at a tertiary hospital. All patients received prophylaxis against AKI with ST and adequate hydration. ST was administered as a bolus 15 minutes before HIPEC and as a 6-hour perfusion afterwards. Renal function was assessed by blood parameters applying Kidney Disease Improving Global Outcomes (KDIGO) criteria. <h3>Results</h3> Thirty-eight patients were included (63.2% women), with a median age of 67 (IQR: 52, 72) years-old. Primary tumours included 27 colonic (71.1%), four appendiceal (10.5%), two ovarian (5.3%), two gastric (5.3%) and others. No significant adverse effects were detected with TS. Three patients (7.9%) developed AKI stage I, two on postoperative day (POD) 1, and one on POD2. On POD7, all of them had recovered from AKI. There were no cases of AKI stage II or III. Prior to the intervention, no patients exhibited hypokalaemia. Between POD 1 and POD 2, 52.6% of patients experienced hypokalaemia, persisting in 34.2% on POD7. Of those with hypokalaemia, 69.6% were mild, 26.1% moderate and 4.3% severe. Before HIPEC, two patients (5.3%) manifested mild hypernatraemia. Between POD1 and POD2, 21.1% developed mild hypernatraemia. All patients had resolved it by POD7. Magnesium serum levels were not monitored frequently enough to allow for evaluation. <h3>Conclusion and Relevance</h3> ST may be a safe and effective prophylactic treatment for cisplatin-induced AKI in HIPEC. Further studies are needed to strengthen these findings. Electrolyte imbalances are a frequent adverse effect of HIPEC with cisplatin, especially hypokalaemia. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest