JOURNAL OF CLINICAL MICROBIOLOGY, May 1995, p. 1185–1191 Vol. 33, No. 5 0095-1137/95/$04.00+0 Copyright  1995, American Society for Microbiology Continuous Quality Improvement for Introduction of Automated Blood Culture Instrument M. ALFA, 1,2 * S. SANCHE, 2 S. ROMAN, 2 Y. FIOLA, 1 P. LENTON, 1 AND G. HARDING 1,2 Microbiology Laboratory, St. Boniface General Hospital, 1 and Department of Medical Microbiology, University of Manitoba, 2 Winnipeg, Manitoba, Canada Received 21 November 1994/Returned for modification 11 January 1995/Accepted 22 February 1995 Despite the critical nature and high cost of blood cultures, hospitals rely on manufacturers’ test site data. As a result, in-hospital testing and compliance evaluation of newly acquired instruments are seldom done. The goal of this study was to apply a continuous quality improvement approach and to develop assessment criteria for all stages from the purchase order, through the on-site instrument evaluation, to the compliance evaluation. Despite the introduction of an automated high-blood-volume instrument (BacT/Alert) in our hospital, 56% of adult patients had only one venipuncture and 89.5% had 20 ml of total blood volume sampled. False positives were associated with overfilling of bottles. These problems occurred because the phlebotomists did not like to perform multiple venipunctures on ill patients; therefore, they were drawing 20 ml of blood from one veni- puncture and splitting it between two bottles. Unknown to the staff, the vacuum in the bottles draws signifi- cantly more than 10 ml of blood; therefore, the first bottle in the set was frequently overfilled and the second bottle was frequently underfilled. A diagrammatic guideline for a new blood culture protocol based on two venipunctures, taken one immediately after the other, to inoculate three bottles was developed. Compliance evaluation demonstrated that within 1 month of starting the new protocol, 74% of patients had at least two or more venipunctures and 60% had 30 ml of blood drawn per patient episode. This study demonstrates the need for continuous quality improvement, including compliance evaluation, to ensure that the potential benefits of newer blood culture technology are actually realized. Blood cultures are one of the most significant single tests performed in the microbiology laboratory (2, 21) and can ac- count for up to 10% of the total microbiology supplies budget. Recently, many ‘‘new-technology’’ automated blood culture systems have been introduced (14, 17, 19, 24, 26). Despite the critical nature of this test, there is generally heavy reliance on the manufacturer’s test site evaluation and little reliance on local in-hospital assessment. Indeed, in some centers, blood culture instruments are brought on-line and used immediately for patient samples throughout the entire hospital with little or no evaluation of effectiveness or compliance with the new system. The need to more closely evaluate blood culture in- struments is reflected by the tighter Food and Drug Adminis- tration criteria now being applied to new blood culture systems (6) and the pressure that tighter budgets have had on justifying instrument purchases and procedure changes. Similarly, many laboratories are recognizing the importance of evaluating com- pliance (8) with volume (9, 10, 15) and skin disinfection (20) guidelines. Robinson (16) has recently reviewed the impact of new technology on overutilization in diagnostic laboratories and has identified the need to critically assess whether such changes actually benefit patient care. Similarly, Bartlett et al. (1) have identified the need for better management of quality in microbiology laboratories. They identified blood volume and number of venipunctures as important issues to assess. How- ever, little information is available to help guide laboratories in their quest for continuous quality improvement (CQI) of blood culture systems. The aim of this study was to develop a standardized CQI approach to ensure that the new-technology blood culture in- strument that we had purchased met our expectations. Through compliance evaluation as part of CQI, we identified inadequacies in the blood culture protocol that meant the advantages that the new automated system offered were not being realized. MATERIALS AND METHODS Patient population. Our Microbiology Laboratory provides service to the St. Boniface General Hospital, which is a 600- to 650-bed tertiary care institution that is affiliated with the University of Manitoba. Blood cultures are received from patients for the following services: obstetrics and gynecology, general med- icine, surgery and its subspecialties, critical care, family practice, geriatrics, psy- chiatry, dialysis, outpatient clinics, neonatology, and the emergency room. Bacterial strains. The bacterial strains listed in Table 1 were tested. All aerobic and facultative bacteria were grown on blood agar consisting of tryptone soya agar base (Oxoid, Unipath Ltd., Basingstoke, Hampshire, England) supple- mented with 5% sheep blood, except the fastidious species Haemophilus influ- enzae, Haemophilus aphrophilus, Neisseria gonorrhoeae, and Neisseria meningiti- dis, which were grown on chocolate agar consisting of GCII agar base (BBL, Becton Dickinson, Cockeysville, Md.) supplemented with 10 mg of hemoglobin per ml and XV supplement (PML Microbiologicals, Tualatin, Oreg.). All anaer- obes were grown on blood agar with hemin and vitamin K 1 , consisting of brucella agar base supplemented with 5% sheep blood and 10 g of vitamin K 1 per ml and 5 g of hemin per ml. Blood agar plates were incubated aerobically at 35°C, chocolate agar plates were incubated in CO 2 at 35°C, and anaerobic plates were incubated in an anaerobic chamber at 35°C. (Coy Laboratory Products, Inc., Ann Arbor, Mich.). Quality control comparison of seeded organisms. In this study, sheep blood was seeded with bacteria to achieve a final concentration of 1 to 50 CFU/ml. Viable counts were performed with each inoculated blood sample to verify the actual number of CFU of bacteria per milliliter. The blood containing seeded bacteria was used to inoculate a BacT/Alert (Organon Teknika, Inc., Scarbor- ough, Ontario, Canada) aerobic bottle and an anaerobic bottle (10 ml each), as well as a Bactec 660 (Becton Dickinson Canada, Inc., Mississauga, Ontario, Canada) aerobic bottle and an anaerobic bottle (5 ml each). Each bottle was placed into the appropriate instrument and monitored according to a 5-day protocol. All bottles were subcultured to chocolate agar (for Haemophilus spp.) or blood agar or blood agar with hemin and vitamin K 1 (for anaerobes) plates when they were identified as positive by the instrument or at the end of the 5-day protocol if they were not detected as positive (i.e., a terminal blind subculture was done with all bottles). * Corresponding author. Mailing address: Microbiology Laboratory, St. Boniface General Hospital, 409 Tache Ave., Winnipeg, Manitoba, Canada R2H 2A6. Phone: (204) 237-2105. Fax: (204) 237-6065. 1185 on July 24, 2020 by guest http://jcm.asm.org/ Downloaded from