Examining the utility of routine perioperative hemoglobin monitoring in patients undergoing radical nephrectomy.

Introduction: Patients undergoing radical nephrectomy (RN) are often admitted with protocolized bloodwork for several days following their operation, yet the clinical value of serial hemoglobin (Hgb) measurements has not been established. This can lead to unnecessary costs and can prolong patient stay, despite the absence of an intervention based on these lab values. This study sought to examine perioperative Hgb values and identify those patients at high risk of bleeding requiring intervention, as well as those patients who are unlikely to require further monitoring.

Methods: Patient and perioperative factors were retrospectively examined for a cohort of 259 radical nephrectomy patients from 2015-2021 in Atlantic Canada. Postoperative Hgb values and transfusion rates were recorded. A multivariate logistic regression analysis was performed to identify variables associated with requiring a blood transfusion.

Results: Overall, 31 (12%) patients required a blood transfusion in the postoperative period. Median estimated blood loss (EBL) was 150 (interquartile range [IQR] 100-300) ml, with a median Hgb change of 15 (IQR 9-22) g/L from preoperative to postoperative day 1 (POD1). In patients with a Hgb loss of ≤15 g/L (n=131), transfusion was only required in four patients (3.1%). Among those with a POD1 Hgb >100 g/L (n=199), only four (2%) required transfusion. These patients were identified as having complications based on hemodynamic instability. On multivariate regression analysis, factors found to be associated with higher transfusion risk were age and intraoperative EBL, while higher preoperative Hgb was found to be associated with a lower transfusion risk.

Conclusions: In patients who have a reassuring POD1 Hgb value, with a drop of <15 g/L or an absolute value of >100 g/L, consideration can be made towards discontinuing routine Hgb testing in the absence of a clinical indication. Age, blood loss, and preoperative Hgb are factors that may affect a patient's overall risk of transfusion.