Predictive factors of hemoglobin drop after robot-assisted radical prostatectomy: a single center prospective study

Robotic surgery provides precise control, allowing for optimal dissection and cutting of tissues while minimizing bleeding. However, a significant drop in hemoglobin (Hb) after robot-assisted radical prostatectomy (RARP) is often recorded. The current study aimed to examine the postoperative Hb drop and its predictive factors in prostate cancer (PCa) patients who underwent RARP. From our tertiary care center's prospectively maintained database, all PCa patients who underwent RARP from January 2022 to January 2023 were identified. For each patient, baseline, anesthesiologic, and surgical characteristics, as well as blood samples before and after surgery, were collected. Multivariable linear and logistic regression models were fitted to investigate potential predictive factors of linear Hb drop or Hb drop ≥ 2 g/dl between preoperative and postoperative day (POD) one, after RARP. Overall, 110 RARP patients were enrolled. Considering the Hb, the median preoperative and POD1 values were 14.6 and 12.7 g/dl respectively (∆ = 1.9, p < 0.001); between POD2 and POD3, no statistically significant difference was recorded (12.4 vs 12.5 g/dl, ∆ = 0.1, p = 0.1). After multivariable analyses, age, BMI, prostate volume, nerve-sparing approach, anesthesia time, intraoperative fluids, intraoperative blood loss, and intraoperative diuresis did not show a statistically significant predictive value (all p > 0.05). The current prospective study showed a statistically significant Hb drop until POD1. After that, a quick stabilization of the Hb value was recorded. This reduction was not correlated with pre- and intraoperative variables. These observations might play an important role in postoperative inpatient RARP management, in both large and low-volume centers.