Portal de Periódicos da CAPES

30. Venipuncture Equipment, Technique, and Hemolysis of Laboratory Blood Samples Obtained in the Emergency Department

2004; Elsevier BV; Volume: 30; Issue: 5 Linguagem: Inglês

10.1016/j.jen.2004.07.036

1527-2966

Debra Seguin, Christine McEachrin, Timothy P. Murphy,

Blood transfusion and management

Research has shown that venipuncture equipment and techniques can cause hemolysis of blood samples. Hemolysis is the damage of red blood cells, which can cause false elevations in some laboratory results, particularly electrolytes. This can and does lead to repeat blood draws for the patient with a potential delay of definitive care and a subsequent increase in length of stay. The purpose of this study was to identify venipuncture equipment and techniques that were associated with hemolysis of blood samples obtained in the emergency department. This study used a prospective, cross-sectional design that reviewed laboratory samples drawn on all patients (≥18 years old) that presented to the emergency department who had blood work ordered. A blood samples were reviewed for hemolysis, technique, and supplies used. These blood samples were drawn as part of patients' routine care from October 1-21, 2003. This study received Institutional Review Board exempt status. ED nursing and technician staff completed data forms (after the blood was drawn) for every blood sample drawn in the emergency department and compared with the laboratory data on hemolysis of the blood samples. This staff was instructed not to change their phlebotomy technique for the study. More than one sample from the same patient could have been included (<20); however, the exact number is unknown. During the analysis process, patient identifiers were kept securely in a locked office and destroyed once the completed phlebotomy tools were matched with the hemolysis analysis. Laboratory technicians examined each sample for hemolyis and dichotomized the results into present or not present. Data collected included technique type (drip, needle/syringe, angiocather/vacutainer) and the equipment size (needle, angiocatheter, and/or syringe) used. Data was analyzed using SPSS. During the 21-day study, 1206 forms were completed with corresponding laboratory analyses. Phlebotomies were done using vacutainers (82.6%), syringes (16.4%), and the drip method (1.0%). In 6.1% of the samples, laboratory results indicated hemolysis. Hemolysis was present in blood samples drawn with syringes (13), vacutainers (57), and the drip method (3) (P = .02). Removing the drip method (small sample) resulted in no statistical difference (P = .645) between syringe and vacutainer techniques. There was a significant difference in hemolysis between smaller (23g and 25g) and larger (<23g) butterfly needles (P < .001). Angiocatheters showed a significant difference (P < .001) between smaller (22g and 24g) versus larger gauges (<22g). Hemolyzed blood samples done by straight needle draw were excluded. A very low rate of hemolysis was found in this study compared to other published reports. No difference in hemolysis was found when using either a needle and syringe or an angiocatheter and a vacutainer. The drip method appears to have a higher rate of hemolysis associated with it; however, the small sample cannot provide a definitive statement. Smaller needle sizes were associated with greater occurrence of hemolysis for both butterfly and angiocatheter. Further research should address all aspects of phlebotomy technique, equipment, and laboratory analysis of hemolysis.