Difference of Body Posture for Venous Blood Collection on Hemoglobin Levels

Abstract

The posture of body during phlebotomy is a critical factor for a successful blood collection. Lying down
or sitting during blood draw contributes to a small but significant alteration in the plasma volume. The
hemoglobin increases by about 5% as the posture changes from lying to sitting. This study investigated
the difference in hemoglobin levels between venous blood collected from lying down and sitting
positions. This study was an observational analytical study with a cross-sectional approach conducted
in July 2021 on thirty medical laboratory students in Palembang. The samples were selected using
proportional random sampling. The blood of research subjects was drawn in a lying position and a sitting
position. The hemoglobin levels between the two positions were analyzed using the dependent t-test.
The results showed the mean hemoglobin level in the lying position was 13.623 gr/dL and that in the
sitting position was 13.663 gr/dL with the p-value of 0.720 > = 0.05). It indicated that there was no
significant difference in the hemoglobin levels between the two groups. The patient's posture during
venipuncture does not affect the hemoglobin levels. Therefore, a blood draw can be performed in either
a lying or sitting position without giving different results in hemoglobin levels