Bubenek-Turconi SI, Văleanu L, Popescu M, et al. - Researchers investigated if the development of acute hemodilution following graded fluid administration can be detected using continuous noninvasive hemoglobin (SpHb) monitoring. Participants were patients (n = 40) who had major vascular or gastrointestinal surgery, who were administered a fluid challenge (FC), comprising 250 mL colloid solution. They repeated FC up to a maximum of 3 times when the stroke volume (SV) raised by ≥ 10%. Following each FC, they recorded laboratory-determined hemoglobin levels (BHb), SpHb, SV, cardiac output, and oxygen delivery (DO₂) values. Findings revealed acute significant reductions in both BHb and SpHb levels in correlation with fluid loading directed at increasing the SV and the DO₂ as part of goal-directed therapy strategy. Experts reported a significant reduction in DO₂ when the administration of an FC was not followed by a significant rise (≥ 10%) in the SV, such a reduction in DO₂ was attributed to the development of acute hemodilution. Although absolute BHb values were not precisely reflected by continuous noninvasive monitoring of SpHb, such monitoring may afford a reliable method to identify the development of acute hemodilution particularly following the administration of at least 500 mL of colloids.