title: Prevention of hemolysis in blood samples collected from intravenous catheters.
abstract: OBJECTIVE
  Samples drawn through intravenous catheters are frequently hemolyzed. We planned a prospective, randomized study to establish whether hemolysis in samples drawn from intravenous catheters may be reduced using S-Monovette® tubes collected by manual aspiration as compared with standard vacuum tubes.
  
  
  METHODS
  We studied 52 consecutive patients admitted to the ED. Blood was drawn through a 20-gauge intravenous catheter. A 5.0mL, Becton Dickinson Vacutainer® SST II Plus serum tube was collected and discarded. In the odd group of patients (i.e., n. 1, 3, 5, etc.), a second SST II tube was drawn with vacuum ("BD-V"), followed by a 5.5mL S-Monovette® serum tube collected with manual aspiration ("SD-A") and an identical S-Monovette collected by vacuum ("SD-V"). In the pair group of patients (i.e., n. 2, 4, 6, etc.), the sequence was modified to "SD-A", "SD-V" and "BD-V". Serum was separated and tested for lactate dehydrogenase (LDH), potassium and cell-free hemoglobin.
  
  
  RESULTS
  The mean concentration of potassium (+2.7% in BD-V and +1.7% in SD-V, respectively), LDH (+15% in BD-V and +7% in SD-V, respectively) and cell-free hemoglobin was significantly increased when samples were collected with vacuum tubes as compared with manual aspiration. No significant differences were observed between SD-V and BD-V. The frequency of hemolyzed samples was higher when blood was collected with the vacuum as compared with SD-A (i.e., 2%), but did not differ between BD-V and SD-V (i.e., 29 versus 31%; p=0.70).
  
  
  CONCLUSIONS
  S-Monovette can be used with vacuum or aspiration collection. This latter approach allows blood drawing with limited shear stress and less likelihood of generating spuriously hemolysis.
authors: Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy. glippi@ao.pr.it
authors: Giuseppe
authors: G
authors: Lippi
authors: Paola
authors: P
authors: Avanzini
authors: Gianfranco
authors: G
authors: Cervellin
mesh_terms: D000368:Aged; D001800:Blood Specimen Collection / Q000295:instrumentation*; D002404:Catheterization / Q000295:instrumentation; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D018962:Phlebotomy / Q000295:instrumentation*; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D013396:Suction; D014618:Vacuum
chemical_list: D006454:Hemoglobins; D007770:L-Lactate Dehydrogenase; D011188:Potassium