Matt King, RN, BSN, CRCST
06-20-2005, 10:24 AM
The article I wrote (below) was once accepted then rejected by a major trade jounal. I was told it was tossed as it was too controversial.
Well, change comes way to hard for some people.
I would enjoy hearing your comments.
Thank you.
mking@stevenshealthcare.org
DEMISE OF THE BOWIE-DICK
by Matt King, RN, BSN, CRCST
Abstract: The BDT (Bowie Dick Test) was developed in 1963 to test the efficacy of the then
brand new High-Vacuum sterilizers to pull and maintain an adequate vacuum (1). In subsequent years the BDT became the standard for the daily testing of all pre-vacuum machines (2).
This article argues that the BDT is no longer necessary for three reasons: 1) the daily testing of machines either with a point of use manufactured BDT or a 'ready to use' version is costly, 2) the reliability of today’s sterilizers (as documented by statistical analysis and examination of records) has improved to such an extent that the BDT is no longer required for test air remaining in the sterilizer chamber after a vacuum is pulled and, 3), it is argued that the BDT was developed t insure the sterilization of reusable cotton dressing: no longer performed in 'first or second world’ hospitals.
By these arguments the author concludes that the BDT is not only unnecessary but does little more than creates re-work and increases expense at a facility.
To eliminate the costly BDT test it was determined to first be necessary to convince the hospitals ICC (Infection Control Committee) that the daily testing was of no value and the loss of testing proved no change in risk to patient outcome. By Washington State Regulations Central Supply departments (CS/SPD, etc.) reports to ICC on clinical matters. A fundamental question arose as to whether or not it would be possible to change a practice standard that AORN (2), AAMI (3) IAHCSA (4) and JCHAO (5) all cite as 'good operating practice' was doable.
A review of the literature demonstrated that practices have been changed only when adequate data provides assurance of safety. For example, witness the change several years ago from ‘time—related’ to ‘event-related’ loss of sterility. It was also acknowledged that any such sweeping change as the BDT would require a great deal of work on the author's part.
Northwest Hospital Seattle, WA), lead by the vision of Chief Executive Officer, Mr. James Hart, entered into the realm of Total Quality Management several years ago. A fundamental portion of TQM involves measurement.
No change could be done without measurement.
My first measurement was cost. How much would the elimination of the daily BDT save the organization? Purchase cost of the brand of BDT used at the time was between two and four dollars* per sterilizer per day. Purchase cost alone was calculated to be between $700 to $1,400.00 per year. In Central Processing we have two high-vac sterilizers so the annual cost was from $1,400.00 to $2,800.00 per unit.
The second cost is more indirect. This would include labor to order the BDT, storage of the unused BDT, use the BDT and storage the results for five years. By direct observation the length of time,
necessary to perform the test itself (per manufacture’s recommended practice) was recorded. This came to six minutes a day for both sterilizers. At a base salary of around $14.00 per hour for a Central Processing Technician (benefits included) this came to $1.40 per day or $530.00 per year. Other costs associated with ordering and storage was eliminated from our final equation to keep our measurement simple. Thus far we have seen that when the cost of purchase is added to the operating cost the per annum figure to process the BDT per machine is around $ 1,930-$3,860.00.
I saw that it would be of financial benefit to the organization to eliminate the BDT. I then faced the question of proving to the clinical oversight groups that the daily testing of Hi-Vac sterilizers was not needed. As you recall the BDT tests whether or not the air has been completely evacuated from an empty and sealed chamber. The vaporized and heated water (steam) replaces the air in the chamber under pressure and allows temperatures to soar above the boiling point of water at sea level. This relationship is described by the Ideal Gas Law (PV=nRT). In short, if the temperature in the chamber is above the boiling point of water, then the pressure in the chamber must be above ambient. Messrs. Bowie and Dick developed a test utilizing surgical towels and chemical indicator tape to 'test' whether or not the inside of a muslin wrapped pack had the air evacuated out of it by first generation (1950s) high vacuum sterilizers.
A bit of history. The purpose of a high-vacuum sterilizer is to save time. A high- vacuum sterilizer is faster than a gravity displacement sterilizer and more loads can be run during a shift, i.e. productivity is greater. In no way is a higher 'level' (safer) of sterilization achieved. In the March 16th, 1963 Lancet Dr, John H. Bowie and Mr. James Dick published a letter to the editor describing the development of the Bowie-Dick Test. In that letter to the editor the test was presented (performed with Huckaback towels and sterilization taped formed in the shape of a St. Andrew's Cross (NOTE: St. Andrew is the patron saint of Scotland-a nice touch as both me were working in Edinburgh, Scotland) as a method for proving the acceptance in the medical community of the "new [high vacuum] sterilizers.", (3). In the literature that followed the letters publication it was clear that the senior Bacteriologist to the Royal Infirmary of Edinburgh (Bowie) had become concerned with the true meaning of 'sterile' and with the ability to predict that conditions leading to sterilization could be met, time and time again by the machines then on the market (4). Of great concern was the ability of the new high-vacuum sterilizers to pull air out of the interior of reusable, cotton dressings and bandages. The hypothesis of the BDT was that if a temperature was reached inside the linen pack to change the chemical indicator tape, then the air (not supersaturated with steam) outside the pack must have been eliminated or 'pulled down' by the pre-vacuum pumping cycle.
This was an era before disposable surgical dressings were widely available. At the time of the BDT, bloody dressings and bandages were routinely removed from the patient, washed re-rolled (often by the night shift nursing staff) and re-sterilized for the next day’s surgeries. This practice in today’s environment of strict sterilization protocols and high labor costs is hard even to imagine.
Early sterilizers pulled a vacuum too fast (manual control) and only once (vs. pulse or vacuum), which sometimes left air trapped inside the tightly wrapped linen packs of bandages (5). This trapped air prevented penetration of steam (thermal heat) and thus prevented sterilization. The failure to penetrate became apparent when a pack was opened and scorched cotton was visible. Bowie and his colleagues demonstrated this point by placing thermocouples inside various packs and sterilizing them. Failure to attain and maintain killing level temperatures was demonstrated in this manner time and time again (6).
Bowie came to believe that it was advantageous to test the sterilizer daily with an artificial test
pack (constructed to mimic a bandage/dressing pack) which staff could then inspect after
running. The proof of penetration of the sterilant would be demonstrated by the uniform change
in the steam indicator tape (7).
Also, should the sterilizer have an air leak test performed on a daily basis. The leak test is a performance question separate from the sterilant penetration. The leak would also show up in the failed BDT. It
followed that if the staff could correctly sterilize test pack once a morning and that if the operator ran the sterilizer in the same fashion each and every time and that the actual packs were
constructed less dense than the test pack then they could be relatively assured the dressing used
by the surgeon would be sterile.
In 1984 Peggy Ryan published an article outlining her concerns with the variability in facilities construction of the BDT Pack (8). Her article centered on the variances, which occurred secondary to the failure of an exact, set of standards details in at construction. Among her concerns were such factors as relative humidity (outside the sterilizer), water content of the towels, changes in the composition of towels (addition of polyester fibers used to increase longevity) and the failure of everyone in agreeing to just what a St. Andrew's cross looks like. Of special note was the wide variance in the performance, compliance and construction between institutions. Ms Ryan's article lead one writer to contact Dr. Bowie who by then was living in retirement near the Zimbabwe city of Harrier. In a published letter Dr. Bowie writes the had been retired fair a number of years and admitted to being:
"..quite out of date. [1984]"(10).
End of Part 1 of 2
Well, change comes way to hard for some people.
I would enjoy hearing your comments.
Thank you.
mking@stevenshealthcare.org
DEMISE OF THE BOWIE-DICK
by Matt King, RN, BSN, CRCST
Abstract: The BDT (Bowie Dick Test) was developed in 1963 to test the efficacy of the then
brand new High-Vacuum sterilizers to pull and maintain an adequate vacuum (1). In subsequent years the BDT became the standard for the daily testing of all pre-vacuum machines (2).
This article argues that the BDT is no longer necessary for three reasons: 1) the daily testing of machines either with a point of use manufactured BDT or a 'ready to use' version is costly, 2) the reliability of today’s sterilizers (as documented by statistical analysis and examination of records) has improved to such an extent that the BDT is no longer required for test air remaining in the sterilizer chamber after a vacuum is pulled and, 3), it is argued that the BDT was developed t insure the sterilization of reusable cotton dressing: no longer performed in 'first or second world’ hospitals.
By these arguments the author concludes that the BDT is not only unnecessary but does little more than creates re-work and increases expense at a facility.
To eliminate the costly BDT test it was determined to first be necessary to convince the hospitals ICC (Infection Control Committee) that the daily testing was of no value and the loss of testing proved no change in risk to patient outcome. By Washington State Regulations Central Supply departments (CS/SPD, etc.) reports to ICC on clinical matters. A fundamental question arose as to whether or not it would be possible to change a practice standard that AORN (2), AAMI (3) IAHCSA (4) and JCHAO (5) all cite as 'good operating practice' was doable.
A review of the literature demonstrated that practices have been changed only when adequate data provides assurance of safety. For example, witness the change several years ago from ‘time—related’ to ‘event-related’ loss of sterility. It was also acknowledged that any such sweeping change as the BDT would require a great deal of work on the author's part.
Northwest Hospital Seattle, WA), lead by the vision of Chief Executive Officer, Mr. James Hart, entered into the realm of Total Quality Management several years ago. A fundamental portion of TQM involves measurement.
No change could be done without measurement.
My first measurement was cost. How much would the elimination of the daily BDT save the organization? Purchase cost of the brand of BDT used at the time was between two and four dollars* per sterilizer per day. Purchase cost alone was calculated to be between $700 to $1,400.00 per year. In Central Processing we have two high-vac sterilizers so the annual cost was from $1,400.00 to $2,800.00 per unit.
The second cost is more indirect. This would include labor to order the BDT, storage of the unused BDT, use the BDT and storage the results for five years. By direct observation the length of time,
necessary to perform the test itself (per manufacture’s recommended practice) was recorded. This came to six minutes a day for both sterilizers. At a base salary of around $14.00 per hour for a Central Processing Technician (benefits included) this came to $1.40 per day or $530.00 per year. Other costs associated with ordering and storage was eliminated from our final equation to keep our measurement simple. Thus far we have seen that when the cost of purchase is added to the operating cost the per annum figure to process the BDT per machine is around $ 1,930-$3,860.00.
I saw that it would be of financial benefit to the organization to eliminate the BDT. I then faced the question of proving to the clinical oversight groups that the daily testing of Hi-Vac sterilizers was not needed. As you recall the BDT tests whether or not the air has been completely evacuated from an empty and sealed chamber. The vaporized and heated water (steam) replaces the air in the chamber under pressure and allows temperatures to soar above the boiling point of water at sea level. This relationship is described by the Ideal Gas Law (PV=nRT). In short, if the temperature in the chamber is above the boiling point of water, then the pressure in the chamber must be above ambient. Messrs. Bowie and Dick developed a test utilizing surgical towels and chemical indicator tape to 'test' whether or not the inside of a muslin wrapped pack had the air evacuated out of it by first generation (1950s) high vacuum sterilizers.
A bit of history. The purpose of a high-vacuum sterilizer is to save time. A high- vacuum sterilizer is faster than a gravity displacement sterilizer and more loads can be run during a shift, i.e. productivity is greater. In no way is a higher 'level' (safer) of sterilization achieved. In the March 16th, 1963 Lancet Dr, John H. Bowie and Mr. James Dick published a letter to the editor describing the development of the Bowie-Dick Test. In that letter to the editor the test was presented (performed with Huckaback towels and sterilization taped formed in the shape of a St. Andrew's Cross (NOTE: St. Andrew is the patron saint of Scotland-a nice touch as both me were working in Edinburgh, Scotland) as a method for proving the acceptance in the medical community of the "new [high vacuum] sterilizers.", (3). In the literature that followed the letters publication it was clear that the senior Bacteriologist to the Royal Infirmary of Edinburgh (Bowie) had become concerned with the true meaning of 'sterile' and with the ability to predict that conditions leading to sterilization could be met, time and time again by the machines then on the market (4). Of great concern was the ability of the new high-vacuum sterilizers to pull air out of the interior of reusable, cotton dressings and bandages. The hypothesis of the BDT was that if a temperature was reached inside the linen pack to change the chemical indicator tape, then the air (not supersaturated with steam) outside the pack must have been eliminated or 'pulled down' by the pre-vacuum pumping cycle.
This was an era before disposable surgical dressings were widely available. At the time of the BDT, bloody dressings and bandages were routinely removed from the patient, washed re-rolled (often by the night shift nursing staff) and re-sterilized for the next day’s surgeries. This practice in today’s environment of strict sterilization protocols and high labor costs is hard even to imagine.
Early sterilizers pulled a vacuum too fast (manual control) and only once (vs. pulse or vacuum), which sometimes left air trapped inside the tightly wrapped linen packs of bandages (5). This trapped air prevented penetration of steam (thermal heat) and thus prevented sterilization. The failure to penetrate became apparent when a pack was opened and scorched cotton was visible. Bowie and his colleagues demonstrated this point by placing thermocouples inside various packs and sterilizing them. Failure to attain and maintain killing level temperatures was demonstrated in this manner time and time again (6).
Bowie came to believe that it was advantageous to test the sterilizer daily with an artificial test
pack (constructed to mimic a bandage/dressing pack) which staff could then inspect after
running. The proof of penetration of the sterilant would be demonstrated by the uniform change
in the steam indicator tape (7).
Also, should the sterilizer have an air leak test performed on a daily basis. The leak test is a performance question separate from the sterilant penetration. The leak would also show up in the failed BDT. It
followed that if the staff could correctly sterilize test pack once a morning and that if the operator ran the sterilizer in the same fashion each and every time and that the actual packs were
constructed less dense than the test pack then they could be relatively assured the dressing used
by the surgeon would be sterile.
In 1984 Peggy Ryan published an article outlining her concerns with the variability in facilities construction of the BDT Pack (8). Her article centered on the variances, which occurred secondary to the failure of an exact, set of standards details in at construction. Among her concerns were such factors as relative humidity (outside the sterilizer), water content of the towels, changes in the composition of towels (addition of polyester fibers used to increase longevity) and the failure of everyone in agreeing to just what a St. Andrew's cross looks like. Of special note was the wide variance in the performance, compliance and construction between institutions. Ms Ryan's article lead one writer to contact Dr. Bowie who by then was living in retirement near the Zimbabwe city of Harrier. In a published letter Dr. Bowie writes the had been retired fair a number of years and admitted to being:
"..quite out of date. [1984]"(10).
End of Part 1 of 2