Comparison of laboratory values obtained by phlebotomy versus saline lock devices.

Author(s): Corbo J, Fu L, Silver M, Atallah H, Bijur P

Publication: Acad Emerg Med, 2007, Vol. 14, Page 23-7

PubMed ID: 17099189 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of obtaining blood specimens through an SLD as opposed to venipuncture on hematocrit, electrolytes, glucose, and cardiac enzyme levels. The effects of catheter size on successful aspiration were also examined. SLD specimens were obtained within 5 minutes of venipuncture specimens, and the first 5 mL of blood obtained through the SLD was discarded.

   Summary of Findings:

   While the overall success rate of obtaining specimens from the SLD was 90.1%, there appeared to be a decline in success rates with increasing catheter gauge, however, sample size was highly varied among the catheter gauges analyzed, and some samples were too small for statistical analysis. No clotted or hemolyzed specimens were obtained using SLD or standard venipuncture for specimen collection. While there were no statistically significant differences in the mean values of any of the tested analytes (hematocrit, serum sodium, potassium, chloride, bicarbonate, glucose, creatine phosphokinase, and troponin I) between the two collection methods, 6.0% of the paired values analyzed exceeded the Bland-Altman limits of agreement, and, with venipuncture taken as the standard, 7.4% of the values obtained from SLD specimens were outside the national recommended Clinical Laboratory Improvement Amendment (CLIA) range. Importantly, the authors state that none of the values exceeding Bland-Altman limits of agreement would have warranted clinical intervention.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Carbohydrate	Clinical chemistry/auto analyzer
   Electrolyte/Metal	Clinical chemistry/auto analyzer
   Small molecule	Clinical chemistry/auto analyzer
   Protein	Clinical chemistry/auto analyzer
   Cell count/volume	Hematology/ auto analyzer
   Cell count/volume	Macroscopic observation
   Morphology	Macroscopic observation

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Cannulation	22-gauge catheter 18-gauge catheter 20-gauge catheter
   Biospecimen Acquisition	Method of fluid acquisition	Venipuncture Saline lock device

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