Background : Many of patients including patients with leukemia, GI bleeding and trauma require repeated blood samples for hematology of laboratory investigations. These vienpunctures are painful to the patient and frustrating for hospital staff when vienpuncture sites are difficult to locate. The purpose of this study was to compare the hematology values of blood samples obtained through saline lock devices with blood specimens obtained through standard veinpuncture.

Materials and Methods: This is a case-control study in which samples of 63 cardiac patients were evaluated. Blood samples were obtained through saline lock catheters and direct vienpuncture. Each participant served as his or her own control. Vienpuncture samples were labeled as the control group and the peripheral venous catheter samples as the case group. In case group before sampling 0.5 ml of withdrawn blood was discarded. Each of the paired samples was analyzed for WBC, RBC, hematocrit, homogolin and PLT

Results: Mean WBC, RBC, hematocrit, hemoglobin PLT were 6372mm³, 4411651mm³, 13/71gr/dl, 40/96% and 187000mm³, respectively in case group and 6240 mm³, 4545397mm³, 13/91gr/dl, 41/03% and 182000 mm³ in control group. No statistical significant differences between hematocrit, hemoglobin, WBC, RBC and PLT values were seen in the blood samples drawn by vienpuncture and saline lock methods.

Conclusions: It is recommended that saline lock catheter (despite intermittent infusion fluids and medications in catheter) can be used for patients having a long hospital stay and requiring repeated blood samples for hematology laboratory investigations.