Characteristics and quality of intra-operative cell salvage in paediatric scoliosis surgery

Bacteremia in the red blood cells obtained from the cell saver in patients submitted to heart surgery

OBJECTIVE

to determine the microbiological characteristics of the red blood cells obtained with the cell saver in heart surgery patients on an extra-body circuit.

METHOD

a cross-sectional and descriptive study conducted with 358 patients scheduled for heart surgery where the saver was used. Sociodemographic variables were collected, as well as from the saver and of the microbial identification in the re-infusion bag proceeding from the cell saver. Informed consent performed.

RESULTS

of the 170 GRAM+ bacteria isolations, the most frequent species were Staphylococcus epidermidis in 69% (n=138) of the cases and Streptococcus sanguinis with a report of 10% (n=20). Significant differences were found in the Staphylococcus epidermidis strain in patients with a Body Mass Index ≥25 (p=0.002) submitted to valve surgery (p=0.001). Vancomycin was the antimicrobial which resisted the Staphylococcus epidermidis strain with a minimum inhibitory concentration of >16 µg/ml.

CONCLUSION

the microbiological characteristics of the red blood cells obtained after processing autologic blood recovered with the cell saver during heart surgery are of GRAM+ bacterial origin, the most isolated species being Staphylococcus epidermidis. Consequently, in order to reduce the presence of these GRAM+ cocci, an antibiotic should be added to the cell saver reservoir, according to a previously established protocol.

Randomized Pilot Trial of Acute Normovolemic Hemodilution in Pediatric Cardiac Surgery Patients

BACKGROUND

Due to the substantial improvement in survival among pediatric patients undergoing congenital heart surgery, reducing early and long-term morbidity is becoming the major focus of care. Blood transfusion is associated with worse postoperative outcomes after cardiac surgery. Acute normovolemic hemodilution (ANH) is a blood conservation strategy that aims to reduce allogenic blood transfusion during cardiac surgery. However, there are scant data regarding its efficacy for pediatric cardiac surgery patients.

METHODS

We designed a single-center, controlled, randomized, pilot trial in patients between 6 and 36 months old undergoing pediatric heart surgery. Patients were equally assigned to undergo ANH prior to initiation of cardiopulmonary bypass or to be managed per usual care. The primary end point was the amount of blood product transfused perioperatively. Secondary end points were markers of morbidity: postoperative bleeding, hematocrit, inotropic agents use, intensive care unit, and hospital stay. The analysis was by intention-to-treat. Estimates of differences between groups are presented with 95% CIs.

RESULTS

Twelve pediatric heart surgery patients were randomized to each group, ANH and usual care. Baseline characteristics were similar between groups. Acute normovolemic hemodilution implementation did not result in a reduction in the administration of blood product transfused (difference between ANH and usual care among patients transfused = -1.4 mL [-29.4 to 26.6], P = .92). Secondary end points were not different between groups.

CONCLUSIONS

In this small trial of pediatric cardiac surgery patients, ANH as a strategy to reduce blood component therapy was safe; however, the study failed to show a reduction in perioperative transfusion or other postoperative outcomes.

Vancomycin added to the wash solution of the cell-saver. Effect on bacterial contamination

OBJECTIVES

The aim of this study is to test whether the addition of a low-dose of antibiotic (vancomycin) to the wash solution (saline) of the cell-saver reduces the incidence of bacterial contamination of the autologous red blood cell (RBCs) concentrate recovered.

MATERIAL AND METHOD

Experimental, randomized, double-blind, parallel group study performed on 20 consecutive patients scheduled for posterior spinal fusion surgery. Intraoperative bleeding was processed through a cell-saver: HaemoLite^® 2+, in which the RBCs were washed according to randomization group, with saline (control group) or saline+10μg/ml^-1 vancomycin (vanco group). Data regarding age, weight, processed and recovered volume, blood count, blood culture, and vancomycin concentration in RBCs concentrates obtained and incidence of fever after reinfusion were collected.

RESULTS

Processed volume was 843±403ml and recovered volume 121±29ml, with haemoglobin concentration 10.4±5.0g/dl^-1 and haematocrit 29.1±15.9% (mean±SD). Recovered RBC concentrate cultures were positive for coagulase-negative Staphylococcus in 5 cases (50%) of the control group while all cultures were negative in the vanco group (P=.016). The difference between the theoretical concentration of vancomycin administered and the concentration determined in the recovered RBC concentrate was 1.31μg/ml^-1 (95% CI 1.19 to 1.43; P=.074).

CONCLUSIONS

The addition of vancomycin at a concentration of 10ug/ml^-1 to the wash solution of the cell-saver achieved similar concentrations in the autologous blood concentrate recovered allowing for bacterial removal, with negative blood cultures in all cases.