Reducing blood sample hemolysis in the emergency department using S-Monovette® in aspiration mode

Background: Blood sample hemolysis continues to be a significant problem in clinical practice. In vitro hemolysis rates up to 77% have been reported in literature. The use of manual aspiration techniques for blood sampling has previously been shown to reduce the burden of erythrocyte injury in the pre-analytical phase compared to the vacuum collection technique. This study compares the hemolysis rates between two blood sampling methods: 5.0 ml BD Vacutainer (R) SSTTM (BDV) and 4.9 ml S-Monovette (R) serum gel tubes in aspiration mode (SMA).Methods: This was a prospective randomised controlled study conducted in an Emergency department (ED). A convenience sample of 191 adult patients, aged 18-90 years old, presenting at the ED and requiring blood samples for serum electrolyte was included in the study. Paired blood samples were obtained through an intravenous cannula from each patient with randomised order of blood draw using SMA or BDV. Patient data was obtained and hemolysis index (HI), serum lactate dehydrogenase (LDH), and serum potassium (K) levels measured.Results: The adjusted mean HI (35.2 vs 21.5 mg/dL, p < 0.001), serum K (4.38 vs 4.16 mmol/L, p < 0.001) and LDH levels (259.6 vs 228.4 U/L, p < 0.001) were significantly higher in blood samples taken using BDV compared to SMA. The frequency of severely hemolyzed (>150 mg/dL) samples was also higher in blood collected using BDV (16.2%) compared to SMA (0%).Conclusions: The burden of hemolysis in blood samples taken from IV cannulae can be effectively reduced with the use of manual aspiration using the S-Monovette (R) blood collection system as compared to BD-Vacutainer.