Amniotic fluid removal during cell salvage in the cesarean section patient

Background: Cell salvage has been used in obstetrics to a limited degree be cause of a fear of amniotic fluid embolism. In this study, cell salvage was combined with blood filtration using a leukocyte depletion filter. A compa rison of this washed, filtered product was then made with maternal central venous blood. Methods: The squamous cell concentration, lamellar body count, quantitative bacterial colonization, potassium level, and fetal hemoglobin concentratio n were measured in four sequential blood samples collected from 15 women un dergoing elective cesarean section. The blood samples collected included (1 ) unwashed blood from the surgical field (prewash), (2) washed blood (postw ash), (3) washed and filtered blood (postfiltration), and (4) maternal cent ral venous blood drawn from a femoral catheter at the time of placental sep aration. Results: Significant reductions in the following parameters were seen when the postfiltration samples mere compared to the prewash samples (median [25 th-75th percentile]): squamous cell concentration (0.0 [0.0-0.1 counts/high -powered field (HPF)] vs. 8.3 counts/HPF [4.0-10.5 counts/HPF], , P < 0.05) ; bacterial contamination (0.1 [0.0-0.2] vs, 3.0 [0.6-7.7] colony-forming u nits (CFU)/ml, P < 0.01); and lamellar body concentration (0.0 [0.0-1.0] vs . 22.0 [18.5-29.5] thousands/mu l, P < 0.01). No significant differences ex isted between the postfiltration and maternal samples for each of these par ameters. Fetal hemoglobin was in higher concentrations in the postfiltratio n sample when compared with maternal blood (1.9 [1.1-2.5] vs. 0.5% [0.3-0.7 ]). Potassium levels mere significantly less in the postfiltration sample w hen compared with maternal (1.4 [1.0-1.5] vs. 3.8 mEq/1 [3.7-4.0]). Conclusions: Leukocyte depletion filtering of cell-salvaged blood obtained from cesarean section significantly reduces particulate contaminants to a c oncentration equivalent to maternal venous blood.