The study was conducted by clinicians at Peking Union Medical College in Beijing, and published in BMC Anesthesiology, with an aim to help clinicians estimate when to conduct invasive hemoglobin measurement to detect possible anemia in patients undergoing spine or cytoreductive surgery.

Masimo said that Dr. Tang and colleagues have decided to determine whether noninvasive, continuous hemoglobin monitoring could aid clinicians in estimating when it might be appropriate to perform an invasive measurement.

The study enrolled 69 adult patients scheduled for spine surgery or cytoreductive surgery for whom estimated blood loss was more than 15% of total blood volume.

The patients were randomly divided into SpHb group with 32 patients and a standard care group containing 37 patients.

In the SpHb group, diagnostic blood samples were drawn when a patient’s SpHb has decreased by 1 g/dL, measured using a Masimo Radical-7 Pulse CO-Oximeter.

In the standard care group, blood samples were drawn at the clinicians’ discretion, and were  subjected to blood gas analysis using a Radiometer ABL800.

The positive predictive value (PPV) of SpHb for the SpHb group and clinician perception in the standard care group were determined in detecting a decrease in lab hemoglobin of more than 1 g/dL or lab hemoglobin of less than 10 g/dL.

The study found that the incidence of unnecessary hemoglobin measurement was lower in the SpHb group than the standard care group. In addition, no difference was observed in transfusion units or postoperative hemoglobin concentrations between the two groups.

The researchers said: “The SpHb trend tracked changes in hemoglobin satisfactorily during surgery and more accurately estimated the appropriate timing for invasive hemoglobin measurements than the clinicians.

“This study was the first diagnostic randomized controlled trial to explore the triage role of Pulse CO-Oximetry in the intraoperative detection of anemia. We found that the trend in SpHb could detect a decrease in Hb in dynamic situations and indicate the appropriate timing for further Hb measurements.”