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The Necessity of Conducting Proper Sterilization

I have seen medical practitioners fret over the cleanliness of their facility all the time. Sometimes, it becomes so irritating that one starts wondering why it is so necessary to clean each and every thing several times during the course of a day.

It was recently that I came upon an article on the internet that shed light on the requirement of cleanliness and proper medical sterilization in laboratories, hospitals and other medical and medicinal facilities. First of all, medical facilities are places that are constantly being visited by different patients. Some of them are suffering from transmissible diseases. In order to make sure that the staff and the patients at the facility do not catch these diseases from one another, it is necessary that the doctors, nurses and technicians adopt the rules and procedures that have been devised and put in place for medical and surgical sterilization.

There are several prescribed methods for effective surgical sterilization which range from simple soap and water rinsing to high-tech cleaning with the help of ultrasonic sterilization. Ultrasonic surgical sterilization is the most preferred method for cleaning medical tools since it is simple and does not take a lot of time. The process can be carried out with minimum effort while producing astonishing results. Very delicate tools, however, need extra time and effort from the staff because they need to be cleaned manually with special care and precision. The next step of surgical sterilization involves submerging them in an ultrasonic cleaning solution inside the machine. Specially designed thongs are used for this purpose.

The machine takes about five to ten minutes for cleaning the equipment. Once the cleaning is done, the instruments are allowed to dry by themselves. These are, then, placed in perfectly clean and sterilized trays.

Manual cleaning requires a brush and a good scrub. The brush is needed in order to clean the rounds and small points and edges on the instruments that cannot be reached by human fingers. This process involves immersing the instrument in a cleaning solution preferably a detergent and scrubbing as well as brushing it with your hands also immersed in the solution.

Medical sterilization is regarded as a major aspect of diagnosis and treatment of ailments. Surgical sterilization ensures that the instruments being used on different patients do not subject them to further infections from each other. It is also imperative for the well being of the staff at the medical facility. If medical sterilization is not properly carried out, it may be harmful for everyone including the doctors.

Gibraltar Laboratories enjoys an impeccable reputation as a health care service provider. The company boasts a long list of satisfied clients.

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Equipment Sterilization – A Necessity for Medical Services

Equipment sterilization plays a major role in laboratory testing and medical services. Instrument sterilization is carried out with the help of devices that are specifically produced for the same purpose and cater to the strict standards that are required for the safety and well being of the patients as well as the doctors, nurses and other staffs. Inappropriate equipment sterilization can pose a great threat on the proper functioning of medical facilities which, in turn, has a profound adverse effect on the health and well being of millions of people all around the world. It is widely accepted that in the absence of proper medical equipment sterilization, medical institution would not be able to function as reliable health care facilities.

There are several kinds of equipment that are used for medical purposes: diagnosis equipment, life support, therapeutic instruments, laboratory equipment and monitors. Diagnostic equipment can determine a disorder or a disease in a patient. Examples of diagnosis equipment are CT scanners, MRI, X-ray machines, PET, etc. Therapeutic equipment is used for assisting those patients who have undergone surgical procedures. Life support equipment maintains the normal bodily functions of a patient whereas, monitoring devices measure the medical state of a patient like vital signs, blood pressure, etc. The equipment in the laboratories is used for the analysis of urine, blood samples, etc.

It is of little consequence which device is being used; since instrument sterilization is a necessity for the proper care and maintenance of each and every medical instrument. It is also important for the purpose of safeguarding against transmissible infections and other diseases. Apart from the disposable equipment that is thrown after a single use, every instrument needs equipment sterilization before and after every use. The monetary aspect of disposing of expensive instruments is also not a viable option.

Instrument sterilization is a process that should be carried out with proper care and precision so that all the instruments can be used time and again for a longer period of time with maximum effectiveness.

Equipment sterilization can be done simply by washing the equipment with detergent and running water. Alcohol can also be used for this purpose. This is a simple sterilization method. However, it may not be suitable for cleaning each and every item in this manner. There are other equipments that need complex and sophisticated sterilization methods like ultrasound cleaning and pressured steam. It is better that the sterilization process is done by a person who is trained in this field and can carry out the process in detail.

Gibraltar Laboratories enjoys an impeccable reputation as a health care service provider. The company boasts a long list of satisfied clients.

Daniel Prince No Comments

USP Statistical Analysis

 

Non-sterile (P)
Rate

Non-sterile (P)
Rate

Units
Tested (N)

Percent chance to fail sterility test (F)

1:10,000

0.0001

1

0.01

1:1000

0.001

1

0.1

1:100

0.01

1

1.0

1:10

0.1

1

11.1

1:10,000

0.0001

5

0.05

1:1000

0.001

5

0.5

1:100

0.01

5

5.3

1:10

0.1

5

82.4

1:10,000

0.0001

10

0.10

1:1000

0.001

10

1.0

1:100

0.01

10

11.1

1:10

0.1

10

271.8

The above probability of a false negative sterility test F is calculated without respect to the sample volume tested. It is based on the number of units tested and the contamination rate P. Obviously, if a preparation has a contamination rate of P and N units are tested for sterility then the percent chance of correctly identifying a true sterility failure F is directly proportional to the volume of medium tested.

In this example I have highlighted the case where 1 in 1000 units are expected to be non-sterile. Ideally, a sterility test will correctly identify this level of contamination. However, the USP <71> test does not accomplish this. The chance of correctly identifying this level of contamination is 1, 0.5 and 0.1% when 10, 5 or 1 units are tested. Thus, even when 10 units are tested the USP sterility test will miss the contamination event 99% of the time.

Non-sterile (P)
Rate

Non-sterile (P)
Rate

Units
Tested (N)

Percent chance to fail sterility test (F)

1:1000

0.001

1

0.1

1:1000

0.001

2

0.2

1:1000

0.001

3

0.3

1:1000

0.001

4

0.4

1:1000

0.001

5

0.5

1:1000

0.001

6

0.6

1:1000

0.001

7

0.7

1:1000

0.001

8

0.8

1:1000

0.001

9

0.9

1:1000

0.001

10

1.0

1:1000

0.001

20

2.0

1:1000

0.001

40

4.2

In this table it is shown that the chances of correctly identifying a contaminated lot when the contamination rate is 1 in 1000 as a function of sample size. When only a single unit is tested then the there is a 0.1% chance of an accurate result or a 99.9% chance of a False negative result. By expanding the test to include 40 units as the sample size the chance of correctly identifying the non-sterile lot slightly increases to about 4.2%.

Accordingly, any rational to justify a reduced number of units tested should take into account the limits of the statistical meaning of the USP sterility test.

Respectfully Submitted,

By: Daniel Prince

 

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USP Sterility test: The probability of a false negative result is high

Non-sterile (P)
Rate

Non-sterile (P)
Rate

Units
Tested (N)

Percent chance to fail sterility test (F)

Percent False NegativeResult

1:10,000

0.0001

1

0.0

99.99

1:1000

0.001

1

0.1

99.90

1:100

0.01

1

1.0

99.01

1:10

0.1

1

9.5

90.48

1:10,000

0.0001

5

0.0

99.95

1:1000

0.001

5

0.5

99.50

1:100

0.01

5

4.9

95.12

1:10

0.1

5

39.3

60.66

1:10,000

0.0001

20

0.2

99.80

1:1000

0.001

20

2.0

98.02

1:100

0.01

20

18.1

81.87

1:10

0.1

20

86.5

13.54

The above probability of a false negative sterility test F is calculated without respect to the sample volume tested. It is based on the number of units tested and the contamination rate P. Obviously, if a preparation has a contamination rate of P and N units are tested for sterility then the percent chance of correctly identifying a true sterility failure F is directly proportional to the volume of medium tested.

In this example refer to the case where 1 in 1000 units are expected to be non-sterile. Ideally, a sterility test will correctly identify this level of contamination. However, the USP <71> test does not accomplish this. The chance of correctly identifying this level of contamination is 2, 0.5 and 0.1% when 20, 5 or 1 units are tested. Thus, even when 20 units are tested the USP sterility test will miss the contamination event 98% of the time

Non-sterile (P)
Rate

Non-sterile (P)
Rate

Units
Tested (N)

Percent chance to fail sterility test (F)

Percent False NegativeResult

1:1000

0.001

1

0.1

99.9

1:1000

0.001

2

0.2

99.8

1:1000

0.001

3

0.3

99.7

1:1000

0.001

4

0.4

99.6

1:1000

0.001

5

0.5

99.5

1:1000

0.001

6

0.6

99.4

1:1000

0.001

7

0.7

99.3

1:1000

0.001

8

0.8

99.2

1:1000

0.001

9

0.9

99.1

1:1000

0.001

10

1.0

99.0

1:1000

0.001

20

2.0

98.0

1:1000

0.001

40

3.9

96.1

In this table it is shown that the chances of correctly identifying a contaminated lot when the contamination rate is 1 in 1000 as a function of sample size. When only a single unit is tested then there is a 0.1% chance of an accurate result or a 99.9% chance of a False negative result. By expanding the test to include 40 units as the sample size the chance of correctly identifying the non-sterile lot slightly increases to about 3.9%.

Accordingly, any rational to justify a reduced number of units tested should take into account the limits of the statistical meaning of the USP sterility test.

Daniel No Comments

Women and Their Beauty: How people see you as more beautiful than you see yourself

womanI know that we are often very critical of how we look and how we sound to others. In general we want to “look good” in the eyes of others. Perhaps our reality of ourselves is vastly different than the the reality of others that know us. This video explores the attitudes of women and compares their description of themselves to that of others as illustrated by a forensic artist. Women are more beautiful in the eyes of others than they are to themselves. Watch this interesting thought exercise.
http://www.facebook.com/photo.php?v=120357218161699Women and Their Beauty: How people see you as more beautiful than you see yourself

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Helping Compounding Pharmacies

I have just returned from an all-day consultation audit of a compounding pharmacy. Our role is to perform a critical audit to help the firm identify the source of a fungal contaminate that was found in its sterile preparations. It is necessary to find the root cause and then the firm must institute both preventive and corrective actions.

We know that current good manufacturing practice regulations and FDA oversight are relatively new to the compounding pharmacy industry. We also all see firsthand how FDA and state Boards of Pharmacy are working closely together because of the tragedies that arose from the poor practices recently in Massachusetts [NECC].

The point of this blog is to let you know that we care about the survival of your industry. We want to work with pharmacies which have integrity about offering only safe scripts for their customers/patients. We can provide over 43 years of knowledge to help you adjust and forward your path to the new current expectations as relates to microbiological monitoring, facility design and training.

 

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Comments on Protein Residue Observed on Single-Use Devices

Recently we learned of a case where a single use device was tested in an academic institution in Europe. It was concluded that the two different, sterile, non-cytotoxic, virgin, single use devices contained protein burden [proburden]  levels of 4.72 and 11 pg/mm2. It was also observed that substantial industrial contaminants like fibers, hair, grease and other chemicals were present in single use devices from a variety of manufacturers. This finding raised a public safety concern and MHRA (Medicines and Healthcare products Regulatory Agency, UK) required a response from the sponsor pertaining to the levels of protein observed. The following comments are provided by Gibraltar Laboratories Inc. [GBL] in an attempt to help sponsors to anticipate this issue and to provide a reasoned approach to understand the meaning of the results.

A possible inference from the MHRA communication is that the device in question is unacceptable because trace levels of molecular markers were observed. Total protein/amino acids detected were 4.72 and 11 pg/mm2 (equivalently 0.472 and 1.1 x 10-3 µg/cm2) for two devices respectively. Currently there is no residual protein value published by regulatory authorities as to the cleanliness benchmark for single-use device. Therefore we choose a comparative approach to interpret these data.

The established regulatory guidance for residual protein, as an indicator of organisms or tissues, in the evaluation of the efficacy of reprocessing reusable devices  is published [AAMI TIR No.30: 2011 – A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical devices.] The benchmark value is less than 6.4 µg/cm2 for protein after a device has been cleaned. This acceptance criterion is >1000-fold higher than what was detected from the single-use devices by MHRA. Then the essential question is whether this 1000-fold less protein residue is properly interpreted as a criterion for cleanliness of single-use devices.

The number one safety concern is infection caused by contamination of medical devices. This is particularly more critical in reusable devices then single-use ones because certain reusable devices such as endoscopes inevitably become contaminated with great load of bioburden (bacteria, fungi and viruses) during usage and all procedures are performed on patients not guaranteed free of infectious agents. For single-use devices, bioburden can be introduced during the entire manufacturing process from initial raw materials to final packaging. However, the types of environmental bioburden associated with single-use devices does not pose a risk as high as the infectious agents, like HIV, HBV, TB, etc, associated with reusable devices where the acceptable limit of cleanliness is  less than 6.4 µg/cm2  protein.

Regardless, reusable or single-use devices all have to be sterilized before usage.  Given the high sterilization assurance level which can be achieved in modern sterilization technology, infectious agents [except for prions] can be inactivated completely. Since protein is ubiquitous in all living organisms and tissues it not unexpected that it remains on the devices after infectious agents are completely inactivated. The present study showed devices passed sterility test. What perspective should be drawn from the trace levels of protein reported to be present by the academic institution? For bacteria, the protein content is estimated to be in the range of 60 to 330 fg per cell (M. Zubkov et al. Determination of Total Protein Content of Bacterial Cells by SYPRO Staining and Flow Cytometry, Appl Environ Microbiol. 1999 July; 65(7): 3251–3257). Based on this data, TIR30 protein acceptance criterion 6.4 µg/cm2 can be converted to protein content from 19.4 – 106.7 x 106 bacterial cells/cm2 or 0.2-1.1 x 106 bacterial cells/mm2, which is likely to be a visible level. If this is safe for reusable devices then a 1000-fold less level found on single use devices should be even safer.

Additionally, in the case of reusable medical devices it is known that residual levels of protein accumulate after repeated use. The reprocessing procedure usually consists of chemical and thermo treatments; protein residue becomes less and less soluble and begins to build up inside devices. This can lead to malfunction during the operation and a life-threatening event. However, for single-use devices, residual accumulation is out of the question. If 6.4 µg/cm2 protein level is acceptable for repetitive use and under the risk of malfunction caused by accumulation, then a 1000-fold less level portends to be unnecessarily burdensome without additional safety.

Having said all of the above, we are not arguing that quality control on single-use devices should be neglected. In the opposite we would like to suggest  more research, better industrial guidance and a more practical approach for quality control.

The protein detection method used in the evaluation of cleanliness of reusable devices and acceptable to the FDA is an ‘in situ’ assay using a modified OPA/NAC reagent spray. Compared to other common protein assays such as BCA or Bradford, which is colorimetrical testing protein in liquid form, it is more sensitive because the analyte doesn’t need to be further diluted with either reagent or extraction buffer. As a practical matter it will be difficult for manufacturers to implement routine monitoring with this technology. We suggest using total organic carbon (TOC) analysis instead as provided at Gibraltar Laboratories.

A TOC analyzer has extremely low limit of detection (ppb). It is fully automated and has been utilized in quality control in the pharmaceutical industry for decades for water quality, cleanliness monitoring, etc. TOC analysis is available through many contract laboratories like GBL. Many pharmaceutical products are administrated intravenously to patients daily. The risk is considerably higher, if they are contaminated, than single-use devices. TOC criteria from the pharmaceutical industry should be stringent enough for manufactures to adopt into its routine quality program for single-use devices. A  TOC assay is superior to a protein assay because it can detect all critical components of life, i.e. protein, carbohydrate, lipid and nucleic acid. Additional benefits provided by TOC also include detecting residues from certain mechanical lubricants and cleaning detergents, etc. TOC can help to track the trend of these residues before they reach a harmful level. An extra assurance level can be provided by TOC analysis due to its ability to detect things which protein assays cannot.

With respect to possible biological reactivity we recommend the ISO 10993 Biocompatibility procedure or USP <87> Biological Reactivity tests, in vitro. Both “cytotoxicity tests” are very sensitive, rapid and inexpensive official methods to assess the safety of medical devices.  In addition, other in vitro tests are available at our laboratory for specialized purposes such as for ophthalmic exposure [e.g., MATTEK].

In summary, the residual protein level found on single-use devices discussed here do not appear to pose any risk to a  patient based on comparative analysis with the acceptance criterion published for reusable devices. TOC and cytotoxicity analyses may be a practical alternative for manufacturers to implement in their routine quality control program.

Tiger Wang, Ph.D. and Daniel Prince, Ph.D.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Microbiological Media – A Basic Overview

Millions of medical tests take place every day across the globe. Many tests require a sample of blood, urine or other bodily fluid or even tissue. This is required to grow the bacteria that a doctor is looking for within a patient’s body. Interestingly, growing bacteria is not the same as growing, for example, a plant. However, there is one important similarity. This similarity is known as food, or microbiological media.

What is Microbiological Media?

Microbiological media, or bacterial culture media, is a growth medium used to grow bacteria. In other words, it contains everything bacteria need to grow outside the body and under laboratory conditions. Bacterial culture media is used when a specific bacterium must be grown in order to confirm the presence of an infection or study a specific bacterium further. There are thousands of different media used today.

Microbiological media can be classified under two primary categories; chemical or organic. A purely chemical media uses chemical medium to provide the needed nutrients to an organism. An organic media contains organic material that a certain bacterium may need to grow.

Furthermore, bacterial culture media can be used to grow a general variety of bacteria. On the other hand, selective media is used when only a certain type of bacteria is to be grown.

How does Microbiological Media work?

To rule out that a finished product such as a drug, medical device, tissue or implant is contaminated with microorganisms bacterial culture media is used. The media enables the microbiologist to identify and quantify any organism so that patient safety is assured.

Why is such Media Important?

It is through the use of a bacterial culture media that the presence of a bacterial infection is either confirmed or not. Although there are other ways of doing so, growing microbes is the most accurate method. In simple words, unless microbiological media existed, accurately confirming a disease would be incredibly difficult.

Whether it is the identification of bacteria for commercial use or for identifying and confirming infections, knowing basic information about microbial media is crucial to understanding it.

For more information, you can visit the website www.gibraltarlabsinc.com.

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Many Different Techniques of Medical Instrument Sterilization

Instrument sterilization is a crucial matter for every laboratory, clinic and hospital. Unless the equipment used is sterilized every so often, health facilities will not be allowed to stay in operation. Contrary to popular belief, there are many different methods of sterilizing medical equipment. Below is a basic look at the many different techniques used to sterilize medical equipment by many laboratories such as Gibraltar Labs.

Sterilization via Autoclave

An autoclave is a machine of varying size. It uses high heat and pressure and steam to sterilize medical equipment. The time needed for sterilization depends on the temperature achieved by the autoclave and the configuration of the materials to be sterilized. The critical factor is that the material must have an unobstructed path to the steam.

Sterilization via Steam

This type of sterilization is rather common in health facilities and is used by the manufacturers of orthopedic instruments and trays to validate their instructions for use. Equipment is put into the main chamber and steam is directed towards the medical equipment. The high heat and steam destroy many organisms and ensure that the instrument is left clean and sterilized.

Sterilization via Flash

This technique is similar to using steam for sterilization, but has one principle difference. Flash sterilizing an object is significantly faster than sterilizing via steam or many other methods.

Sterilization via Dry Heat

Sterilizing medical equipment via dry heat is an effective method of sterilizing medical equipment. Dry heat is directed towards the medical equipment and any microorganisms are destroyed. This is because the high heat coagulates blood proteins and ensures that microorganisms are destroyed.

Sterilization via Moist Heat

This was one of the earliest techniques of sterilization. Hot air (with water vapor) is directed towards medical instruments, denaturing many microorganisms in the process. This ensures that any bacteria or microbe growing on the instrument is destroyed.

Sterilization via Radiation

Radiation, especially gamma radiation, is used to sterilize medical equipment. Gamma radiation ensures that many different types of microbes are destroyed. Interestingly, radiation is always used to sterilize scalpels and many other metallic medical instruments.

As evident, there are many methods of sterilizing medical equipment. Although not every technique is employed by any hospital, many of the above techniques are still used to sterilize medical equipment.  In conclusion, patients can rest assured that the equipment used to maintain their health is clean, up to the standard and perfect for use in or on their body.

Contributed By: This article was contributed by Gibraltar Labs to educate patients about the various sterilization techniques used in the medical and health industry today.

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How Medical Equipment is Sterilized – A Simple Overview

Ever wondered how medical equipment is sterilized? Ever wondered what the procedure for medical device cleaning and sterilization was? Well, here is a basic overview of medical instrument sterilization and cleaning. Mind you, different hospitals and clinics may have different or more specific approaches. However, this is a basic overview.

Frequent Cleaning

Whenever a medical instrument is used, it is constantly cleaned after every use. This ensures that blood or other infectious material or bacteria do not accumulate on the instrument. If that were to happen, it becomes even more difficult to remove the stains.

Thorough Cleaning with Steam

Even though medical equipment is wiped down after every use, medical device cleaning via steam is crucial for complete instrument sterilization. In most cases, sterilization using steam is a vital process that most hospitals employ to safeguard patient safety.

Instrument sterilization using steam leaves no harmful chemical residues and all microbes are destroyed.

Thorough Drying

After thorough cleaning, medical equipment is thoroughly dried. This is an important process for complete instrument sterilization. Proper medical device cleaning requires that equipment should be thoroughly washed and dried before it is put into an autoclave. Many hospitals use the process of sterilization via dry heat to dry medical instruments.

Putting Equipment in an Autoclave

Once equipment has been properly washed and dried, it is then put into an autoclave. It is here that more heat, steam and high pressure is used to truly ensure proper instrument sterilization. Each instrument is placed approximately 1 inch away from each other and the machine is closed and the sterilization is allowed to continue for the validated cycle.

Maintain a Log

Once instrument sterilization has been achieved, it is vital that a medical device cleaning and sterilization log is maintained. Documentation is critical for compliance of the necessary steps required to achieve patient safety.

For more information, visit www.gibraltarlabsinc.com.