Proposition of a simple binary grading of estimated blood loss during colon surgery

Intraoperative estimated blood loss (EBL) is often reported in nearly all surgical papers; however, there is no consensus regarding its measurement. The aim of this study was to determine whether EBL (ml) is as reliable and reproducible in predicting complications as a simple binary grading of EBL.

All consecutive patients undergoing colectomies between January 2015 and December 2018 were included. EBL was assessed prospectively by the surgeon and anaesthesiologist in ml and with a binary scale: bleeding "as usual" versus "more than usual" by the surgeon. Differences between pre- and post-operative haemoglobin levels (ΔHb g/dl) were correlated to EBL. Blood loss impact on 30-day postoperative morbidity was analysed.

A total of 270 patients were included, with a mean age of 65 years (SD 17). Mean EBL documented by surgeons correlated to EBL by anaesthesiologists (79.5 ml, SD 99 vs. 84.5 ml, SD 118, ϱ = 0.926, p < 0.001). Surgeons and anaesthesiologists' EBL correlated also with ΔHb (ϱ = - 0.273, p = 0.01 and ϱ = - 0.344, p = 0.01, respectively). Patient with surgeon EBL ≥ 250 ml or graded as "more than usual" bleeding had significantly more severe complications (8% vs. 20%, p = 0.02 and 8% vs. 27%, p = 0.001, respectively).

Anaesthesiologist and surgeon's EBL correlated with ΔHb. Simple grading of blood loss as "usual" and "more than usual" predicted severe complications and higher mortality rates. This simple binary grading of blood loss in colon surgery could be an alternative to the estimation of blood loss in ml as it is easy to apply but needs to be validated externally.