FIRST CLINICAL IMPLICATIONS OF PERIOPERATIVE RED-CELL VOLUME MEASUREMENT WITH A NONRADIOACTIVE MARKER (SODIUM FLUORESCEIN)

We measured red cell volume (RCV) with the nonradioactive marker sodiu m fluorescein (SoF) in 30 patients undergoing gynecological operations . Sixteen patients underwent preoperative isovolemic hemodilution (PIH D). RCV measurements were performed before and after PIHD and at the e nd of the operation. All RCVs were related to corresponding hematocrit (hct) levels. We report a simplified method for its clinical applicat ion by reducing the number of blood samples required. To validate our method, we compared RCV within the PIHD bags (bag RCV) with the differ ence of the patients' RCV before and after PIHD. Bag RCV obtained duri ng PIHD (mean 399 +/- 81 mL) was measured with a precision of 4.2% by using SoF. There was a significant difference (mean 286 +/- 401 mt; P < 0.05) between intraoperatively estimated and measured blood loss. Th e blood loss tended to be underestimated and, in some cases, was under estimated or overestimated substantially. Preoperative and postoperati ve hct values only offered an imprecise estimation of the patients' RC V. We conclude that RCV measurement using SoF is a precise method for monitoring changes in RCV during PIHD and surgical operation. Implicat ions: We measured red cell volume changes of 30 patients with the nonr adioactive marker sodium fluorescein before and after hemodilution and postoperatively with a high precision. We frequently found large diff erences between intraoperatively estimated and measured blood loss. Pr eoperative hematocrit values offered an imprecise estimation of the pa tients' red cell volume.