The effect of intraoperative furosemide administration during minimal invasive oesophageal surgery on the occurrence and prevention of postoperative acute kidney injury - A retrospective observational cohort study

Background: The decision for volume expansion or fluid removal during surgery is often based on urinary output. The use of intravenous furosemide can reverse oliguria but may harm renal function. The aim of this study is to explore the occurrence of postoperative acute kidney injury (AKI) in patients receiving furosemide compared to patients not receiving furosemide. Methods: Single centre cohort study. Adults scheduled for elective minimal invasive esophagectomy from October 2015 until December 2021 were included. The primary outcome was the occurrence of postoperative AKI in patients. AKI was defined according KDIGO. Secondary outcomes were AKI stages, 90-days mortality, and the occurrence of AKI in patients with intraoperative oliguria. Results: 202 patients were included. Furosemide and non-furosemide patients had comparable baseline characteristics. 75% of the patients received <= 5mg furosemide. Patients treated with furosemide and without furosemide had similar occurrence rate of AKI (47.2% versus 39.0%, p = 0.45) and severity of AKI (p = 0.40). There was a significant decrease of serum creatinine postoperatively on day 1 and day 2-7, for all patients (p<0.001), furosemide patients (p<0.01 and p<0.01) and non-furosemide patients (p<0.001 and p<0.001). There was no significance between intraoperative diuresis < 0.5 mL.kg-1.h-1 or < 0.3mL.kg-1.h-1 and the presence of postoperative AKI (p=0.67; p=1.00). No statistical significance for 90-days mortality was found between AKI and no AKI patients (p=0.70). Conclusion: An intravenous dose furosemide to treat intraoperative oliguria during elective minimal invasive esophagectomy in patients that were considered euvolemic, did not prevent AKI nor did it result in AKI.