The Effect of Tourniquet Application on Serum Calcium and Inorganic Phosphorus Determination

Abstract

Venous blood sampling is usually performed using a tourniquet to help locate and define peripheral veins to achieve successful and safe venipuncture. Despite widespread usage of tourniquets for venipuncture by phlebotomists, very few are aware of the effects of tourniquet application on laboratory parameters. This study was set out to determine the influence of different tourniquet application times on total serum calcium and phosphorus concentrations in healthy individuals. A total of hundred (100) healthy subjects were used for the study and three (3) set of venous blood samples were collected from each subjects without tourniquet application, 1min and 5min after tourniquet applications respectively. Samples were collected into plain containers and allowed to clot at room temperature for 20 minutes, centrifuged and serum separated. The samples were analysed for calcium and phosphorus concentrations using WHO approved methods and standard operating system (SOP).  Data obtained were analysed statistically using Two-Way Analysis of variance (ANOVA) SPSS statistical package (version 20). The result revealed a significant increase (P<0.05) in concentrations of total and ionized calcium in samples collected after 5minutes of tourniquet application. The concentration of inorganic phosphate (Pi) was not affected by the application and removal of the tourniquet. This study showed that the acceptable period recommended for tourniquet application should be within 60 seconds. Therefore, if blood sample cannot be collected within 60 seconds, non-application of tourniquet should be used especially for calcium profile determination.

DOI: 10.7176/JHMN/65-07

Publication date: August 31^st 2019