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Evaluating the protective value of hospital gowns
AJIC 178
Letters to the Editor
April 1999
nosocomial influenza cases were detected t h r o u g h surveillance. • The n u m b e r s for 1996 i n c r e a s e d to 1577 of the 2300 employed, giving a r e s p o n s e rate of 69%. No n o s o c o m i a l influenza cases were d e t e c t e d t h r o u g h surveillance. • The n u m b e r s for 1997 i n c r e a s e d to 1664 of the 2300 employed, giving a r e s p o n s e rate of 72%. Two n o s o c o m i a l influenza cases were d e t e c t e d t h r o u g h surveillance m e t h o d s . One p a t i e n t was visited b y a family m e m b e r w h o was d i a g n o s e d w i t h influenza shortly after visiting the patient. In s u m m a r y , the r e s p o n s e rate i n c r e a s e d from 35% to 72% w i t h t h e i m p l e m e n t a t i o n of t h e n e w v a c c i n a t i o n p r o g r a m . The n u m b e r of n o s o c o m i a l influenza cases has decreased, as have h o s p i t a l i z a t i o n costs a n d sick leave. Overall, R a p i d City Regional H o s p i t a l S y s t e m of Care has e x p e r i e n c e d a s u b s t a n t i a l savings in o u r multifaceted i m m u n i z a t i o n p r o g r a m . Beth Boersma, LPN, CIC Tamara Rhames, RN, CIC James Michael Keegan, MD Rapid City Regional HospitalSystem of Care Rapid City, South Dakota References
1. Hall KL, Holmes SS, Evans ME. Increasing hospital employee participation in an influenza vaccine program. AJIC Am J Infect Control 1998;26:367-8. 2. Centersfor Disease Control and Prevention. Prevention and control of influenza. Recommendations of the advisory committee on immunization practices (ACIP). MMWR Morb Mortal Wldy Rep 1996;45:1-22. 3. Evans ME, Hall KL, Berry SE. Influenza control in acute care hospitals. AJICAm J Infect Control 1997;25:35%62. 4. Adal KA, Flowers RH, AnglimAM, Hayden FG, Titus MG, Coyner BJ, et al. Prevention of nosocomial influenza. Infect Control Hosp Epidemiol 1996;17:641-8. EVALUATING THE PROTECTIVE HOSPITAL GOWNS...
VALUE OF
To the Editor: The focus of the article by G r a z n o w et al, 1 Eval-uation of the protective value of hospital gowns against blood strike-through and methicillin-resistant Staphylococcus aureus penetration, initially a p p e a r s to be the protective value of isolation a n d cover type of gowns w o r n b y health care workers a n d hospital visitors. However, the perform a n c e capabilities of the gowns are c o m p a r e d with several types of gowns that are w o r n in a n operating r o o m (OR) setting in w h i c h the level of exposure anticipated is far greater. This c o m p a r i s o n is evidenced by the type of m a t e r i a l of which 2 gowns are m a d e (eg, 97%-100% polypropylene spunbond/meltblown/spunbond laminate). As w o u l d be expected, the level of protection they
provide is far greater t h a n that of a n o t h e r OR gown material that is neither a l a m i n a t e n o r polypropylene treated. The s a m e holds true for the 3 cover gowns t h a t were evaluated. W h e r e a s one is m a d e of a 100% p o l y p r o p y lene-treated (highly r e s i s t a n t t h e r m o p l a s t i c resin) nonwoven material, its protective c a p a b i l i t y is c o m p a r e d w i t h t h a t of two 100% woven cotton r e u s a b l e gowns (1 n e w a n d 1 washed). Again, as w o u l d b e expected, t h e p o l y - p r o p y l e n e - t r e a t e d d i s p o s a b l e gown p r o v e d to be m o r e effective. As n o t e d in all the tests, the "washed REUSE" outp e r f o r m e d the "new REUSE." This result is m o r e t h a n likely a t t r i b u t a b l e to the a p p a r e n t l y loosely woven, r e a d i l y p e r m e a b l e 100% c o t t o n fabric s h r i n k i n g d u r i n g the l a u n d r y process(es) a n d the tightening up of the (warp a n d fill) yarns. Actually, the results of this s t u d y of isola-tion/cover gowns d u p l i c a t e those r e p o r t e d b y this s a m e g r o u p 6 years ago. 2 In t h e i r earlier study, 11 different m a t e r i a l s were examined. Once again, as w o u l d be expected, the double-layered, treated, o r l a m i n a t e d m a t e r i a l s were f o u n d to p r o v i d e a h i g h e r level of resistance to p e n e t r a tion of b l o o d t h a n those that were either single layer, u n t r e a t e d , o r n o t laminates. Yet a n o t h e r study was done by this s a m e group on a material's resistance to blood penetration. Rather t h a n gowns, the materials that were e x a m i n e d were those c o m m o n l y used in a variety of l a b o r a t o r y coats. 3 F o u r of the ten fabrics were the traditional type of reusable polyester/cotton blends. As expected, they all were found to be relatively m i n i m a l l y resistant a n d dramatically outp e r f o r m e d b y their disposable counterparts m a d e of polypropylene-treated o r l a m i n a t e construction materials. As a m e m b e r of the original a d hoc c o m m i t t e e on "aseptic barrier" materials w h o s e constituents repres e n t e d t h e A m e r i c a n College of S u r g e o n s , t h e Association of Operating R o o m Nurses, the Association of Practitioners in Infection Control, a n d the textile industry, all 3 of these studies r e m i n d m e of the first c o m p r e h e n s i v e study b y Laufrnan et al* p u b l i s h e d 23 years ago a n d c o n f i r m e d 4 years later? B o t h studies included a variety of b o t h n o n w o v e n disposable a n d woven reusable materials that were being m a r k e t e d at the t i m e as effective "barriers" on the basis of the materials passing the industry's i n f a m o u s M a s o n J a r test. In a d d i t i o n to i n t r o d u c i n g the c o m m u n i t y to a new t e r m - strike-through the results of his investigation revealed that some m a t e r i a l s were totally ineffective. On the o t h e r hand, the m o r e recent studies c o m p a r e the effectiveness of several materials that are k n o w n to be liquidresistant with several that are k n o w n to possess little, if any, protective capability.
AJIC Volume 27, Number 2
Letters to the Editor
Because t h e results of the recent s t u d y are predictable o n the basis of p r e v i o u s work, it can only be
viewed as b e i n g a fruitless exercise in d e m o n s t r a t i n g the obvious. However, in the process, it implies t h a t a n e e d exists for h e a l t h care workers, visitors, a n d labor a t o r y p e r s o n n e l to w e a r liquid-resistant protective type of apparel. Considering the intensity of the p r e s s u r e s b e i n g exerted o n h e a l t h care p r o v i d e r s to reduce, let alone contain, costs, this theoretic inference c a n only b e viewed as b e i n g p r e d i c a t e d b y w h a t has b e e n d e s c r i b e d as "anecdotal experience a n d c o m m e r c i a l interests r a t h e r t h a n scientific studies. "6 Nevertheless, the test methodologies used by b o t h L a u f m a n a n d this research group for assessing a material's protective capability should not be overlooked a n d are p a r t i c u l a r l y noteworthy. C o n t r a r y to t h e A m e r i c a n Society for Testing Materials' pseudo test methods that are currently being widely used by the industry for this purpose, neither of these test methodologies require the use of expensive equipment, special supplies, or special training of personnel. More important, c o m p a r e d with the pass/fail results of the American Society for Testing Materials' tests that characterize a material as being liquid-proof o r impervious, they enable the infection control professional to distinguish between the levels of protection that materials can provide and thereby facilitate the selection of an a p p r o p r i a t e p r o d u c t for the level of exposure anticipated. 7 Nathan L. Belkin, PhD Clearwater, Florida References 1. Graznow JW, Smith JW, Nichols RL, et al. Evaluation of the pro-
2. 3. 4.
5.
6. 7.
tective value of hospital gowns against blood strike-through and methicillin-resistant Staphylococcus aureaus penetration. AJICAm J Infect Control 1998;26:85-93. Lovitt SA, Nichols RL, Smith JW, et al. Isolation gowns: a false sense of security? AJICAm J Infect Control 1992;20:185-91. Smith JW, Mazik AC, Lovitt SA, et al. Variabilityof laboratory coat resistance to blood strikethrough. Clin Chem 1994;40(3):450-63. Laufman H, Eudy WW, Vandernoot AM, et al. Strike-through of moist contamination by woven and nonwoven surgical materials. Ann Surg 1975;181:6:857-62. Laufman H, Siegal JD, and Edberg SC. Moist bacterial strikethrough of surgical materials: confirmatory tests. Ann Surg 1979;189:68-74. Nichols RL. Postoperative wound infections. N Engl J Med 1982;307:1701-2. Belkin NL. The new American Society for Testing and Materials tests: all that glitters is not gold. AJIC Am J Infect Control 1994;22:172-6.
179
b e e n p r e d i c t e d f r o m the results of previous articles. The i m p e t u s of this s t u d y was to e x a m i n e different types of h o s p i t a l gowns c u r r e n t l y being u s e d in hospitals b y using a variety of testing m e t h o d s . Obviously, a cover g o w n s h o u l d not be directly c o m p a r e d with a n operating r o o m (OR) gown b e c a u s e t h e y have different r e q u i r e m e n t s a n d thus m u s t m e e t different criteria. Nevertheless, we were able to s h o w t h a t the tested cover gown was, in fact, m o r e protective t h a n one of the disp o s a b l e (OR No. 3) o r the r e u s a b l e OR gown (new or washed). The testing indicates t h a t gowns c u r r e n t l y b e i n g u s e d in the OR e n v i r o n m e n t are nonprotective. Although n o n r e i n f o r c e d o r c o a t e d c o t t o n OR gowns have essentially b e e n r e p l a c e d in the United States b y m o r e protective materials, they still are m a r k e t e d a n d in use in o t h e r countries. We a g r e e w i t h Dr Belkin's a s s e s s m e n t of t h e A m e r i c a n Society for Testing Materials' testing of protective clothing for passage of synthetic b l o o d o r bloodb o r n e pathogens. These pass/fail tests will only indicate gowns t h a t m e e t specific testing c o n d i t i o n s n o t often seen in actual g o w n usage. F o r this reason, we tested the gowns with a b a t t e r y of tests to assess b l o o d strikethrough, b a c t e r i a l passage, d r y spore passage, a n d bacterial filtration efficiency. The results then can be used in c o m b i n a t i o n to d i s t i n g u i s h differing levels of protection a n d a i d in the selection of gowns. Although the p o o r results of s o m e gown fabrics m i g h t be obvious to s o m e readers, they still are n o t as widely k n o w n as they should be. We did not m e a n to i m p l y t h a t a n e e d exists for all p e r s o n n e l to w e a r liquidr e s i s t a n t apparel. We have always stressed t h a t protective gowns o r o t h e r protective clothing m u s t b e c h o s e n for the tasks p e r f o r m e d , c o n d i t i o n s anticipated, a n d t i m e r e q u i r e d to be worn. All tasks do n o t r e q u i r e the s a m e level of protection. S u r g e r y with m u c h b l o o d loss r e q u i r e s m o r e p r o t e c t i o n t h a n dressing w o u n d s o r visiting a patient. E c o n o m i c factors always s h o u l d be of s e c o n d a r y i m p o r t a n c e in the choice of protection. Ronald Lee Nichols, MS, MD Jeffrey W. Smith, MS, MPH Ruth Waterman, BS Anita C. Muzik, BS, MT(ASCP) Tulane UniversityMedical Center New Orleans, Louisiana
PSEUDOMENINGITIS
CAUSED
B Y ACINETOBAC-
TER BAUMANNII To the Editor:
REPLY
To the Editor:
We a p p r e c i a t e Dr Belkin's c o m m e n t s r e g a r d i n g o u r article a n d agree t h a t s o m e of the findings m i g h t have
P s e u d o i n f e c t i o n s c a u s e d b y a w i d e v a r i e t y of m i c r o o r g a n i s m s are b e i n g r e p o r t e d w i t h i n c r e a s e d frequency. M o s t cases of p s e u d o i n f e c t i o n a r e c a u s e d b y blood culture pseudobacteremias contaminated during b l o o d s p e c i m e n collection/processing. P s e u d o m e n i n -
Letters to the Editor
April 1999
nosocomial influenza cases were detected t h r o u g h surveillance. • The n u m b e r s for 1996 i n c r e a s e d to 1577 of the 2300 employed, giving a r e s p o n s e rate of 69%. No n o s o c o m i a l influenza cases were d e t e c t e d t h r o u g h surveillance. • The n u m b e r s for 1997 i n c r e a s e d to 1664 of the 2300 employed, giving a r e s p o n s e rate of 72%. Two n o s o c o m i a l influenza cases were d e t e c t e d t h r o u g h surveillance m e t h o d s . One p a t i e n t was visited b y a family m e m b e r w h o was d i a g n o s e d w i t h influenza shortly after visiting the patient. In s u m m a r y , the r e s p o n s e rate i n c r e a s e d from 35% to 72% w i t h t h e i m p l e m e n t a t i o n of t h e n e w v a c c i n a t i o n p r o g r a m . The n u m b e r of n o s o c o m i a l influenza cases has decreased, as have h o s p i t a l i z a t i o n costs a n d sick leave. Overall, R a p i d City Regional H o s p i t a l S y s t e m of Care has e x p e r i e n c e d a s u b s t a n t i a l savings in o u r multifaceted i m m u n i z a t i o n p r o g r a m . Beth Boersma, LPN, CIC Tamara Rhames, RN, CIC James Michael Keegan, MD Rapid City Regional HospitalSystem of Care Rapid City, South Dakota References
1. Hall KL, Holmes SS, Evans ME. Increasing hospital employee participation in an influenza vaccine program. AJIC Am J Infect Control 1998;26:367-8. 2. Centersfor Disease Control and Prevention. Prevention and control of influenza. Recommendations of the advisory committee on immunization practices (ACIP). MMWR Morb Mortal Wldy Rep 1996;45:1-22. 3. Evans ME, Hall KL, Berry SE. Influenza control in acute care hospitals. AJICAm J Infect Control 1997;25:35%62. 4. Adal KA, Flowers RH, AnglimAM, Hayden FG, Titus MG, Coyner BJ, et al. Prevention of nosocomial influenza. Infect Control Hosp Epidemiol 1996;17:641-8. EVALUATING THE PROTECTIVE HOSPITAL GOWNS...
VALUE OF
To the Editor: The focus of the article by G r a z n o w et al, 1 Eval-uation of the protective value of hospital gowns against blood strike-through and methicillin-resistant Staphylococcus aureus penetration, initially a p p e a r s to be the protective value of isolation a n d cover type of gowns w o r n b y health care workers a n d hospital visitors. However, the perform a n c e capabilities of the gowns are c o m p a r e d with several types of gowns that are w o r n in a n operating r o o m (OR) setting in w h i c h the level of exposure anticipated is far greater. This c o m p a r i s o n is evidenced by the type of m a t e r i a l of which 2 gowns are m a d e (eg, 97%-100% polypropylene spunbond/meltblown/spunbond laminate). As w o u l d be expected, the level of protection they
provide is far greater t h a n that of a n o t h e r OR gown material that is neither a l a m i n a t e n o r polypropylene treated. The s a m e holds true for the 3 cover gowns t h a t were evaluated. W h e r e a s one is m a d e of a 100% p o l y p r o p y lene-treated (highly r e s i s t a n t t h e r m o p l a s t i c resin) nonwoven material, its protective c a p a b i l i t y is c o m p a r e d w i t h t h a t of two 100% woven cotton r e u s a b l e gowns (1 n e w a n d 1 washed). Again, as w o u l d b e expected, t h e p o l y - p r o p y l e n e - t r e a t e d d i s p o s a b l e gown p r o v e d to be m o r e effective. As n o t e d in all the tests, the "washed REUSE" outp e r f o r m e d the "new REUSE." This result is m o r e t h a n likely a t t r i b u t a b l e to the a p p a r e n t l y loosely woven, r e a d i l y p e r m e a b l e 100% c o t t o n fabric s h r i n k i n g d u r i n g the l a u n d r y process(es) a n d the tightening up of the (warp a n d fill) yarns. Actually, the results of this s t u d y of isola-tion/cover gowns d u p l i c a t e those r e p o r t e d b y this s a m e g r o u p 6 years ago. 2 In t h e i r earlier study, 11 different m a t e r i a l s were examined. Once again, as w o u l d be expected, the double-layered, treated, o r l a m i n a t e d m a t e r i a l s were f o u n d to p r o v i d e a h i g h e r level of resistance to p e n e t r a tion of b l o o d t h a n those that were either single layer, u n t r e a t e d , o r n o t laminates. Yet a n o t h e r study was done by this s a m e group on a material's resistance to blood penetration. Rather t h a n gowns, the materials that were e x a m i n e d were those c o m m o n l y used in a variety of l a b o r a t o r y coats. 3 F o u r of the ten fabrics were the traditional type of reusable polyester/cotton blends. As expected, they all were found to be relatively m i n i m a l l y resistant a n d dramatically outp e r f o r m e d b y their disposable counterparts m a d e of polypropylene-treated o r l a m i n a t e construction materials. As a m e m b e r of the original a d hoc c o m m i t t e e on "aseptic barrier" materials w h o s e constituents repres e n t e d t h e A m e r i c a n College of S u r g e o n s , t h e Association of Operating R o o m Nurses, the Association of Practitioners in Infection Control, a n d the textile industry, all 3 of these studies r e m i n d m e of the first c o m p r e h e n s i v e study b y Laufrnan et al* p u b l i s h e d 23 years ago a n d c o n f i r m e d 4 years later? B o t h studies included a variety of b o t h n o n w o v e n disposable a n d woven reusable materials that were being m a r k e t e d at the t i m e as effective "barriers" on the basis of the materials passing the industry's i n f a m o u s M a s o n J a r test. In a d d i t i o n to i n t r o d u c i n g the c o m m u n i t y to a new t e r m - strike-through the results of his investigation revealed that some m a t e r i a l s were totally ineffective. On the o t h e r hand, the m o r e recent studies c o m p a r e the effectiveness of several materials that are k n o w n to be liquidresistant with several that are k n o w n to possess little, if any, protective capability.
AJIC Volume 27, Number 2
Letters to the Editor
Because t h e results of the recent s t u d y are predictable o n the basis of p r e v i o u s work, it can only be
viewed as b e i n g a fruitless exercise in d e m o n s t r a t i n g the obvious. However, in the process, it implies t h a t a n e e d exists for h e a l t h care workers, visitors, a n d labor a t o r y p e r s o n n e l to w e a r liquid-resistant protective type of apparel. Considering the intensity of the p r e s s u r e s b e i n g exerted o n h e a l t h care p r o v i d e r s to reduce, let alone contain, costs, this theoretic inference c a n only b e viewed as b e i n g p r e d i c a t e d b y w h a t has b e e n d e s c r i b e d as "anecdotal experience a n d c o m m e r c i a l interests r a t h e r t h a n scientific studies. "6 Nevertheless, the test methodologies used by b o t h L a u f m a n a n d this research group for assessing a material's protective capability should not be overlooked a n d are p a r t i c u l a r l y noteworthy. C o n t r a r y to t h e A m e r i c a n Society for Testing Materials' pseudo test methods that are currently being widely used by the industry for this purpose, neither of these test methodologies require the use of expensive equipment, special supplies, or special training of personnel. More important, c o m p a r e d with the pass/fail results of the American Society for Testing Materials' tests that characterize a material as being liquid-proof o r impervious, they enable the infection control professional to distinguish between the levels of protection that materials can provide and thereby facilitate the selection of an a p p r o p r i a t e p r o d u c t for the level of exposure anticipated. 7 Nathan L. Belkin, PhD Clearwater, Florida References 1. Graznow JW, Smith JW, Nichols RL, et al. Evaluation of the pro-
2. 3. 4.
5.
6. 7.
tective value of hospital gowns against blood strike-through and methicillin-resistant Staphylococcus aureaus penetration. AJICAm J Infect Control 1998;26:85-93. Lovitt SA, Nichols RL, Smith JW, et al. Isolation gowns: a false sense of security? AJICAm J Infect Control 1992;20:185-91. Smith JW, Mazik AC, Lovitt SA, et al. Variabilityof laboratory coat resistance to blood strikethrough. Clin Chem 1994;40(3):450-63. Laufman H, Eudy WW, Vandernoot AM, et al. Strike-through of moist contamination by woven and nonwoven surgical materials. Ann Surg 1975;181:6:857-62. Laufman H, Siegal JD, and Edberg SC. Moist bacterial strikethrough of surgical materials: confirmatory tests. Ann Surg 1979;189:68-74. Nichols RL. Postoperative wound infections. N Engl J Med 1982;307:1701-2. Belkin NL. The new American Society for Testing and Materials tests: all that glitters is not gold. AJIC Am J Infect Control 1994;22:172-6.
179
b e e n p r e d i c t e d f r o m the results of previous articles. The i m p e t u s of this s t u d y was to e x a m i n e different types of h o s p i t a l gowns c u r r e n t l y being u s e d in hospitals b y using a variety of testing m e t h o d s . Obviously, a cover g o w n s h o u l d not be directly c o m p a r e d with a n operating r o o m (OR) gown b e c a u s e t h e y have different r e q u i r e m e n t s a n d thus m u s t m e e t different criteria. Nevertheless, we were able to s h o w t h a t the tested cover gown was, in fact, m o r e protective t h a n one of the disp o s a b l e (OR No. 3) o r the r e u s a b l e OR gown (new or washed). The testing indicates t h a t gowns c u r r e n t l y b e i n g u s e d in the OR e n v i r o n m e n t are nonprotective. Although n o n r e i n f o r c e d o r c o a t e d c o t t o n OR gowns have essentially b e e n r e p l a c e d in the United States b y m o r e protective materials, they still are m a r k e t e d a n d in use in o t h e r countries. We a g r e e w i t h Dr Belkin's a s s e s s m e n t of t h e A m e r i c a n Society for Testing Materials' testing of protective clothing for passage of synthetic b l o o d o r bloodb o r n e pathogens. These pass/fail tests will only indicate gowns t h a t m e e t specific testing c o n d i t i o n s n o t often seen in actual g o w n usage. F o r this reason, we tested the gowns with a b a t t e r y of tests to assess b l o o d strikethrough, b a c t e r i a l passage, d r y spore passage, a n d bacterial filtration efficiency. The results then can be used in c o m b i n a t i o n to d i s t i n g u i s h differing levels of protection a n d a i d in the selection of gowns. Although the p o o r results of s o m e gown fabrics m i g h t be obvious to s o m e readers, they still are n o t as widely k n o w n as they should be. We did not m e a n to i m p l y t h a t a n e e d exists for all p e r s o n n e l to w e a r liquidr e s i s t a n t apparel. We have always stressed t h a t protective gowns o r o t h e r protective clothing m u s t b e c h o s e n for the tasks p e r f o r m e d , c o n d i t i o n s anticipated, a n d t i m e r e q u i r e d to be worn. All tasks do n o t r e q u i r e the s a m e level of protection. S u r g e r y with m u c h b l o o d loss r e q u i r e s m o r e p r o t e c t i o n t h a n dressing w o u n d s o r visiting a patient. E c o n o m i c factors always s h o u l d be of s e c o n d a r y i m p o r t a n c e in the choice of protection. Ronald Lee Nichols, MS, MD Jeffrey W. Smith, MS, MPH Ruth Waterman, BS Anita C. Muzik, BS, MT(ASCP) Tulane UniversityMedical Center New Orleans, Louisiana
PSEUDOMENINGITIS
CAUSED
B Y ACINETOBAC-
TER BAUMANNII To the Editor:
REPLY
To the Editor:
We a p p r e c i a t e Dr Belkin's c o m m e n t s r e g a r d i n g o u r article a n d agree t h a t s o m e of the findings m i g h t have
P s e u d o i n f e c t i o n s c a u s e d b y a w i d e v a r i e t y of m i c r o o r g a n i s m s are b e i n g r e p o r t e d w i t h i n c r e a s e d frequency. M o s t cases of p s e u d o i n f e c t i o n a r e c a u s e d b y blood culture pseudobacteremias contaminated during b l o o d s p e c i m e n collection/processing. P s e u d o m e n i n -