Evaluation of Safety Devices for Preventing Percutaneous Injuries Among Health-Care Workers During Phlebotomy Procedures:
Minneapolis-St. Paul, New York City, and San Francisco, 1993-1995
January 17, 1997
Health-care workers (HCWs) are at risk for infections with bloodborne pathogens resulting from occupational exposures to blood through percutaneous injuries (PIs). Phlebotomy, one of the most commonly performed medical procedures, has been associated with 13%-62% of injuries reported to hospital occupational health services1,2 and with 20 (39%) of the 51 documented episodes of occupationally acquired human immunodeficiency virus (HIV) infection reported in the United States (CDC, unpublished data, 1996). Although safety devices designed to prevent PIs associated with phlebotomy have been available for use in the United States, clinical evaluation of these devices has been difficult because 1) ascertainment of PIs is difficult (many injuries are unreported,2,3 and observation of all procedures is impractical because phlebotomy is performed throughout the hospital by different groups of HCWs at all hours), 2) data to calculate PI rates (i.e., the number of phlebotomies performed and devices used) are not routinely available, 3) a large number of phlebotomies must be evaluated because of the low rates of phlebotomy-related PI, and 4) rates of safety-feature activation are difficult to assess. This report summarizes a collaborative study by CDC and six hospitals to evaluate safety devices for phlebotomy. The findings indicate that use of safety devices significantly reduced phlebotomy-related PI rates while having minimal clinically apparent adverse effects on patient care.*
The study was conducted in two phases during 1993-1995 at six university-affiliated hospitals in Minneapolis-St. Paul, Minnesota (three hospitals), New York, New York (one hospital), and San Francisco, California (two hospitals). Each hospital selected the products to be evaluated (vacuum-tube blood-collection devices and/or winged steel needles with safety features). The assessment was restricted to a comparison of safety devices with conventional devices, not with other safety devices. Products evaluated included a resheathable winged steel needle (Safety-Lok[trademark] [Becton Dickinson, Franklin Lakes, New Jersey]** [six hospitals]); a bluntable vacuum-tube blood-collection needle activated while in the patient's vein (Punctur-Guard[trademark] [Bio-Plexus, Inc., Tolland, Connecticut] [three hospitals]); and a vacuum-tube blood-collection needle with a hinged recapping sheath (Venipuncture Needle-Pro[trademark] [Smith Industries (Concord Portex), Keene, New Hampshire] [four hospitals]). Each product requires the HCW to activate the safety feature during or after phlebotomy. Before introducing safety devices, each hospital conducted a comprehensive training program for HCWs that included "hands-on" experience with the equipment.
During phase I (mean duration among the hospitals: 10 months; range: 9-12 months), hospitals used conventional phlebotomy devices and conducted enhanced surveillance for injuries (e.g., encouraging reporting, publishing notices in the hospital newsletter, posting educational materials, and/or providing inservice training for staff). An anonymous survey was distributed to four groups of HCWs who routinely perform phlebotomies*** to estimate their rates of underreporting of PIs to hospital surveillance systems and to determine the average number of phlebotomies performed each day and average number of days worked each week. The rates of PIs associated with phlebotomy devices for HCWs in each of these four groups were estimated by dividing the number of phlebotomy-related PIs reported to the hospital's surveillance system during the study period (adjusted for underreporting by occupation) by the total number of phlebotomies performed (estimated from the daily average number of phlebotomies performed by each HCW, the number of HCWs in each of the four groups, and the duration of the study period).
During phase II (mean duration among the hospitals: 12 months; range: 6-15 months), investigators replaced conventional phlebotomy devices with safety devices hospitalwide, monitored supplies of phlebotomy equipment to attempt to ensure that only safety devices were available, continued enhanced surveillance for injuries, and inventoried the autoclaved contents of a representative sample of disposal containers for sharp instruments to determine rates of use of safety devices and conventional devices and rates of activation of safety features. The HCW survey was repeated 1-2 months before the end of phase II, and the estimated PI rates for safety and conventional devices were compared. The second HCW survey also included questions to assess HCW satisfaction with safety devices and to determine the occurrence of adverse effects in patients that were apparent at the time of the phlebotomy.****
The overall response rate for each of the two HCW surveys was approximately 75%, based on estimates of the number of HCWs who received survey forms; 1699 HCWs responded in phase I and 1421 in phase II. Overall, respondents acknowledged reporting 302 (54%) of 563 needlestick injuries they had sustained from all types of needles during the previous year. Reporting rates varied by occupation: 91% of injuries among phlebotomists were reported, as were 68% among nurses, 35% among medical students, and 31% among residents. Within occupations, reporting rates were similar among hospitals and between the two surveys. Because estimated rates of phlebotomy-related PI by device and occupation were similar for each hospital in which a particular device was used, data were aggregated among hospitals to permit comparison of PI rates for safety and conventional phlebotomy devices. Compared with conventional devices, PI rates were lower for safety devices.
Of 41 PIs associated with safety devices, 34 (83%) involved winged steel needles and seven (17%) involved vacuum-tube blood-collection needles. Twenty-five (61%) involved an injury before activation of the safety feature was appropriate or possible (e.g., within seconds after the device was removed from the vein); six (15%) occurred during activation of the safety feature (all with Safety-Lok[trademark]). For eight (20%), the safety feature had not been activated, and for two (5%), the mechanism of injury was unknown. Safety devices constituted 12,681 (89%) of the 14,261 phlebotomy devices in autoclaved sharps-disposal containers. In the phase II HCW survey, HCWs were asked "Do you prefer the safety device over conventional equipment?" Among 1108 HCWs, 1879 responses were related to one or more of the three devices; 822 (44%) responded yes; 622 (33%), no; and 435 (23%), unsure. Reported by: M Mendelson, MD, R Solomon, MS, E Shekletski, Mt. Sinai Medical Center, New York City. K Henry, MD, S Campbell, MSPH, A Collins, St. Paul Ramsey Medical Center, St. Paul; J Thurn, MD, F Lebahn, MT, Minneapolis Veterans Affairs Medical Center, Minnesota; F Rhame, MD, Univ of Minnesota Hospital, Minneapolis. J Gerberding, MD, R Fahrner, MS, K Turner-Hubbard, MS, San Francisco General Hospital; P Jensen, MD, San Francisco Veterans Affairs Medical Center, California. Hospital Infections Program, National Center for Infectious Diseases, CDC.
Editorial Note: The findings in this report suggest that safety devices for phlebotomy can reduce the risk for occupational PIs among HCWs. In particular, there was a significant reduction in phlebotomy-related PIs associated with use of each of the vacuum-tube blood-collection devices and a reduction in PIs associated with use of the winged steel needles. Further decreases in phlebotomy-related PIs might have been possible with increased use of safety devices and/or increased activation of safety features by HCWs. Experts have recommended that safety devices include safety features that activate automatically and do not rely on activation by HCWs.4,5 Although the assessment of potential patient complications in this study was limited, short-term complications were clinically minimal, and although patients were not systematically monitored for long-term follow-up, phlebotomy needles are not indwelling devices and long-term complications of phlebotomy are rare.
Results of this study also suggest that safety devices for phlebotomy may be generally acceptable to users. Activation rates of safety features and user acceptability may be influenced by factors such as the perceived risk for occupational infection by the HCW, design of the device, training provided before and after introduction of the device, length of time needed to become adept at using the device, ease of use, necessary changes in technique, and previous experience with safety devices.5 Further analyses will assess whether safety-feature activation rates and user acceptability in this study varied by hospital, city, occupation, or device used. Acceptability of a device to an institution may be influenced by cost.
In this study, only 54% of PIs were reported to hospital surveillance systems -- a rate consistent with those documented in previous studies (range: 5%-60%2,3). Failure to report PIs may compromise appropriate postexposure management, including postexposure prophylaxis for HIV and hepatitis B virus, and assessment of occupational hazards and preventive interventions.6,7 Health-care institutions and HCWs must further assess reasons for underreporting and improve reporting of all occupational blood exposures.
The Occupational Safety and Health Administration requires that primary methods to reduce occupational PIs include engineering controls,8 and the Food and Drug Administration has urged that needleless or recessed needle systems be used to replace hypodermic needles for accessing intravenous administration sets.9 Some manufacturers are continuing efforts to develop and refine safety devices to improve the effectiveness and acceptability of products. The findings in this report and in a companion report evaluating blunt suture needles10 suggest that safety devices can be an effective component in a needlestick-prevention program. The Public Health Service is evaluating the implications of these and other data in assessing the possible need for further guidance on selection, implementation, and evaluation of safety devices in health-care settings.
* Single copies of this report will be available free until January 16, 1998, from the CDC National AIDS Clearinghouse, P.O. Box 6003, Rockville, MD 20849-6003; telephone (800) 458-5231 or (301) 217-0023.
** Use of trade names and commercial sources is for identification only and does not imply endorsement by the Public Health Service or the U.S. Department of Health and Human Services.
*** Phlebotomists (including laboratory technicians who frequently draw blood); nurses (on representative medical and surgical wards, intensive-care units, and in the emergency department); residents (medical, pediatric, and surgical); and medical students (third- and fourth-year).
**** Examples of adverse effects include vein trauma resulting in hematoma, increased patient discomfort, and the need for repeated phlebotomy attempts. Because certain events reported as patient adverse effects (e.g., slow blood return or other difficulty drawing blood, sometimes requiring repeat phlebotomies) also were considered technical difficulties, responses were classified as "adverse patient effects or technical difficulties."
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