title: The impact of fist clenching and its maintenance during venipuncture on routine hematology testing.
abstract: BACKGROUND
  Prevention of a disturbance of the blood vessel allows phlebotomists to collect a blood specimen by venipuncture that will truly mirror the patient condition. This study was aimed to evaluate the impact of repeated fist clenching and maintenance of the fist during blood collection by venipuncture for routine hematology testing.
  
  
  METHODS
  Blood were collected from 16 healthy volunteers with two separate sequential procedures, entailing standard venipuncture with hand opened throughout blood collection, or clenching the fist six times before venipuncture and maintaining the fist until completion of blood collection. The parameters tested included red blood cell (RBC) count, hemoglobin, hematocrit, mean corpuscular volume (MCV), RBC distribution width, white blood cell count and differential, including neutrophils, lymphocytes, monocytes, eosinophils, basophils, large unstained cells, platelet count, mean platelet volume, and reticulocytes. The results were reported as median and interquartile range. The comparison of data obtained with the two different venipuncture procedures (i.e., with or without fist clenching and closed hand) was performed with Wilcoxon-Mann-Whitney ranked-pairs test. The degree of statistical significance was set at P<.01.
  
  
  CONCLUSIONS
  Fist clenching and maintenance during blood collection for routine hematology testing was effective to increase the MCV by 1.2% (P<.001). All others hematological parameters were not significantly biased by fist clenching, though hematocrit, neutrophils, eosinophils, and reticulocytes displayed mindful of trends. We hence advise patients against clenching their fist before blood collection for hematology testing.
authors.affiliation: Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and Movement Sciences - University of Verona, Verona, Italy.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Lima-Oliveira
authors.affiliation: Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and Movement Sciences - University of Verona, Verona, Italy.
authors.forename: Gian Cesare
authors.initials: GC
authors.lastname: Guidi
authors.affiliation: Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and Movement Sciences - University of Verona, Verona, Italy.
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Salvagno
authors.affiliation: Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and Movement Sciences - University of Verona, Verona, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
mesh_terms: D000328:Adult; D005260:Female; D006225:Hand / Q000502:physiology*; D006403:Hematologic Tests / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D018962:Phlebotomy / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data
keywords: blood specimen collection; clinical laboratory techniques; laboratory variability; medical errors; patient safety; pre-analytical phase