[Pre-analytical errors in blood sampling: an observational study on specimen collection technique and laboratory results]

Abstract

Introduction: Around 60-70% of diagnostic and therapeutic decisions are based on blood exams. Several errors occur during the pre-analytic phase.

Aims: of this study were: to describe nurses' behaviours in blood specimen collection; to describe prevalence and type of pre-analytical errors; to assess the association between pre-analytical errors and occurrence of unsuitable specimens.

Methods: An observational cross-sectional study was conducted by means of a structured form based on up-to-date clinical recommendations. A researcher observed nurses' behaviors during 172 blood sampling procedures in medical, surgical and emergency care settings. Unsuitable procedures were registered.

Results: Most behaviours were correct, however some significantly diverged from recommended practices: active and passive patient identification; respect of antiseptic solution's drying time; rapid removal of tourniquet when blood started flowing. The prevalence of unsuitable specimen reports was significantly higher when the procedure involved a small calibre vein (RP: 0.19; IC95% 0.04 - 0.98; p = 0.03) and when blood drawing was difficult (RP; 3.83; IC95% 1.63 - 9.01; p <0.001).

Conclusions: The pre-analytical phase is important for the diagnostic process and safety of patients. Although some factors – as patients' characteristics – are non-modifiable, some nurses' behaviours could be improved to reduce risk of pre-analytical errors. Further studies are needed to clarify the associations between pre-analytical errors and laboratory outcomes.