oa Evaluation of an Intervention to Decrease False Positive Blood Culture Contamination Rates in Emergency Department

Introduction

Blood cultures are commonly performed in hospitals daily as it is employed to detect infections that are spreading through the bloodstream (eg; bacteremia, septicemia). This is possible because the bloodstream is usually a sterile environment. Positive blood cultures indicate either bacteremia, or false positive blood cultures from contamination with bacterial skin flora through improper technique. False positive blood cultures are associated with unnecessary hospitalization and/or extended length of stay with consequent financial burden. False positive blood culture rates in Emergency Departments (ED) are often twice as high as on the medical wards. We present the results of an intervention – ANTT (Aseptic Non-touch technique) to decrease false Positive blood culture rates at Hamad General Hospital during the period from Nov 2014 through Nov 2015.

Aim

The HGH Microbiology lab indicator showed that our blood culture contamination rate has been consistently higher than the international benchmark, thereby we aim to reduce it in the critical area of ED BY 50% by the end of July 2015 and at least 90% by end of February 2016.

Methods

A pilot area was chosen in the Emergency Dept. to do a study for 44 weeks after which blood culture kits (previously trolleys & trays were used) containing sterile gloves, masks, and blood culture supplies were introduced into the Critical area of ED-HGH in August 2015. Training included- new instructions to have two staff members present when drawing blood cultures (Preceptor-preceptee methodology) there by prohibiting drawing blood cultures from pre-existing lines and proper follow-up of every step. False positive blood culture rates were measured in the weeks preceding and the weeks following, this intervention.

Results

In the 8 weeks following the intervention, the average false positive blood culture contamination rate in HGH ED reached 1.9%–(which was the benchmark) out of 318 blood culture samples. In the 6 months preceding, the blood culture contamination rates ranged from 4% to 1.5% each month.Conclusion:Blood culture kits and educational training on proper technique resulted in significant reduction (> 60%) in the false positive blood culture rate in the Critical areas of ED-HGH. Studies at other institutions have suggested that reducing the false positive blood culture rate could decrease costs by preventing unnecessary hospitalizations and administration of unnecessary antibiotics, as well as helping to prevent the development of multi-drug resistant organisms.