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

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.