REVIEW DATE: 12/04
REVISION DATE: 12/01
WISHARD MEMORIAL HOSPITAL POLICY MANUAL
DEPARTMENT: Pharmacy Services
POLICY NO: 731-562
SUBJECT: Aseptic Technique
establish an educational training program on proper aseptic technique for
Pharmacy Employees involved in the preparation of parenteral products.
pharmacy employees involved in the preparation of parenteral products shall be
trained on utilizing proper aseptic technique.
Employees will be inserviced on aseptic technique annually.
Employees will demonstrate competency in aseptic technique procedures
ASEPTIC PREPARATION OF PARENTERAL PRODUCTS
the use of parenteral therapy continues to expand, the need for centralized
hospital intravenous admixture preparation has grown as well.
In addition, demand by practitioners for aseptic preparation of other
compounded products, such as sterile irrigations and ophthalmic solutions, has
also increased. Recognizing this
need, many hospital pharmacy departments have devoted increased resources to
programs for aseptic preparation of sterile products.
In conjunction with the use of sterile equipment and supplies, an
understanding of laminar air flow principles, the proper use of the laminar
air flow hood, and development and maintenance of skillful manipulative
technique by personnel are essential for the compounding of products that are
free of microbial and particulate contamination.
program will review the clean room concept, including laminar air flow
principles; proper use of the laminar air flow hood; appropriate attire and
aseptic technique; use of syringes, needles, vials, and ampuls; and basic IV
admixture compounding procedures.
* * * *
definition, sterile products are free of all living microorganisms.
In addition, parenteral solution must be relatively free of particles
and free of pyrogens, which are usually bacterial toxins capable of causing a
fever. The goal of using specific
clean room equipment and procedures in conjunction with proper aseptic technique
is to allow the manipulation of sterile products without contamination with
microorganisms, pyrogens, or particles.
air typically contains many thousands of suspended particles per cubic foot,
most of which are too small to be seen with the naked eye, including
contaminants such as dust, pollens, smoke, and bacteria.
To provide a safe environment for sterile dosage form preparation,
there are several steps which should be taken to reduce the number of
particles in the air.
sterile compounding area should be cleaned daily and segregated from normal
pharmacy operations, patient specimens, nonessential equipment, and other
materials that produce particles. For
example, the introduction of cardboard into the clean environment should be
avoided whenever possible. Traffic
flow into a clean area should be minimized.
Other more sophisticated aspects of clean room design include special
filtration or treatment systems for incoming air ultraviolet irradiation,
air-lock entry portals, sticky mats to remove particulates from shoes, and
positive room air pressure to reduce contaminant entry from adjacent rooms
products should be prepared in a "Class 100" environment, containing
no more than 100 particles per cubic foot that are 0.5 micron or larger in
size. Thus, laminar flow hoods are utilized in the hospital setting
to achieve a "Class 100" environment.
Developed in the early 1960, laminar flow hoods are available in a
variety of sizes and styles. There
are two common types of laminar flow hood, horizontal flow and vertical flow.
flow hoods operate, first, by drawing contaminated room air through a
prefilter by means of an electrical blower within the food (Fig. 1).
The prefilter, similar to a furnace filter, removes only gross
contaminants and should be cleaned or replaced on a regular basis. Prefiltered air is then pressurized within a plenum to
assure that a consistent distribution of air flow is presented to the final
filtering apparatus. Constituting
the entire back portion of a hood's work area, this "high efficiency
particulate air", or HEPA, filter removes 99.97% of particles that are
0.3 micron or larger, thereby eliminating airborne microorganisms. The underlying principle of the laminar flow hood is that the
constant flow of twice-filtered, laminar sheets or layers of
"aseptic" air, at a rate of approximately 90 linear feet per minute
across the work surface, physically sweeps the work area and prevents the
entry of contaminated room air.
flow hoods which utilize a vertical flow of filtered air are also available. In vertical flow hoods, HEPA filtered air emerges from the
top and passes downward through the work area.
Because exposure to some antineoplastic (anticancer) drugs may be
harmful, they are usually prepared in biological safety cabinets, which
utilize vertical air flow, to maintain sterility and protect the operator.
The advantage of biological safety cabinets is that the risk of
exposure to airborne drug is minimized by containing air flow within the hood.
For more information on biological safety cabinets, see the American
Society of Hospital Pharmacists' videotape entitled "Safe Handling of
critical principle of laminar flow hood utilization is that nothing must
interrupt the flow of air between the HEPA filter and a sterile object.
The introduction of a foreign object between a sterile object and the
HEPA filter presents the possibility that contaminants from the foreign object
may be carried onto the sterile object. To
maintain sterility, nothing should pass behind a sterile object in a horizontal
flow hood, or above a sterile object in a vertical flow hood.
materials placed within the laminar flow hood disturb the patterned flow of
air emanating from the HEPA filter. This
"zone of turbulence" created behind an object could potentially
extend outside the hood, pulling or allowing contaminated room air into the
aseptic working area (Fig. 2). When
laminar air flow is accessible to all sides of an object, the zone of
turbulence extends approximately 3X the diameter of that object.
When laminar air flow is not accessible to an object on all sides (for
example, when placed adjacent to a vertical wall), a zone of turbulence is
created that may extend 6x the diameter of the object (Fig. 3).
For these reasons it is advisable to place and work with objects as far
into the hood as is practically feasible without blocking air vents, and to
maintain unobstructed air flow between the HEPA filter and sterile objects.
Also, when working in the hood, the hands should be positioned so that
air flow between the HEPA filter and sterile objects is not blocked.
following are general principles for proper laminar flow hood operation:
All aseptic manipulations should be performed at least 6 inches within
the hood to prevent the possibility of reflected contamination from the
worker's body or "backwash" contamination resulting from air
patterns developing at the laminar flow hood-room air interface.
A laminar flow hood should be left operating continuously.
If turned off, however, the machine should not be used for a
specified period of time when reactivated, such as 30 min., depending on the
hood manufacturer's recommendations.
Before use, all interior working surfaces of the laminar flow hood
should be cleaned with approved disinfectant such as cavicide and clean wipes.
Cleaning should be performed from back to front (away from the HEPA
filter in horizontal flow hoods), so that contaminants are moved out of the
hood. The hood should be cleaned
often throughout the compounding period.
Some materials are not soluble in alcohol and may initially require the
use of water in order to be removed. In
addition, Plexiglas sides, found on some types of laminar flow hoods, should
be cleaned with warm soapy water or hydrogen peroxide as in the APreparing
Parenteral Products@ to avoid damage.
Nothing should be permitted to come in contact with the HEPA filter. This includes cleaning solutions, aspirate from syringes,
or glass from ampuls, which should not be broken directly toward the filter.
A laminar flow hood should be positioned away from excess traffic,
doors, air vents, or anything that could produce air currents capable of
introducing contaminants into the hood.
Jewelry should not be worn on the hands or wrists when working in the
laminar flow hood since it may introduce bacteria or particles into the clean
Actions such as talking and coughing should be directed away from the
laminar flow hood working area, and any unnecessary motion within the hood
should be avoided to minimize the turbulence of air flow.
Only those objects essential to product preparation should be placed in
the laminar flow hood. Do not put
paper, pens, labels, or trays into the hood.
10. Laminar flow hoods should be tested by qualified personnel annually, whenever the hood is moved, or if filter damage is suspected. Specific tests are employed to certify air flow velocity and HEPA filter integrity.
the laminar flow hood provides an aseptic environment, safe for the manipulation
of sterile products, it is essential that strict aseptic technique be employed
in conjunction with the proper hood operation.
It is important to remember that the use of the laminar flow hood
alone, without the observance of aseptic technique, cannot insure product
first component of good aseptic technique concerns personal attire.
Clean garments, which are relatively particulate free, should be worn
when preparing sterile products. Clean
room attire will depend on institutional needs and policies.
Many facilities provide clean scrub suits or gowns for this purpose.
Hair covers and shoe covers may also help reduce particulate or
bacterial contamination, and some experts claim that the use of surgical masks
and gloves is warranted as well.
used properly, the laminar flow hood removes nearly all airborne contaminants.
Thus, touch is the most common means of contaminating a sterile
product. Since the fingers harbor
countless bacterial contaminants, proper hand washing is extremely
important. The hands, nails,
wrists, and forearms should be scrubbed thoroughly for at least 30 seconds
with a brush, warm water, and appropriate bactericidal soap before performing
aseptic manipulations. Chlorhexidine
gluconate in a detergent solution is preferred, as it has been shown to
produce the greatest decrease in normal hand flora when compared to povidone-iodine
or hexachlorophene. Hand
washing should be performed frequently, especially upon having left and
returned to the compounding area, in order to reduce the possibility of touch
gel may also be used to resterilize
addition to hand washing, another important factor in aseptic preparation of
sterile products is the correct use of appropriate sterile equipment and
supplies, including syringes and needles.
are made of either glass or plastic. Glass
syringes are most often used when medication is to be stored in the syringe
for an extended period of time, since most drugs are more stable in glass. disposable plastic syringes are most frequently used in
preparing the majority of sterile products, however, because they are cheaper
and medications will only be in contact with the syringe for a short period of
are two basic parts of a syringe: the barrel and the plunger (Fig. 4). The
plunger, which passes inside the barrel of the syringe, has a flat disc or lip
for manipulation at one end and a cone-shaped rubber piston at the other.
The top collar of the syringe barrel helps prevent the syringe from
slipping during manipulation, while the tip provides the point of attachment
for a needle. Many syringes have
a locking mechanism at the tip, such as the Luer-lock, which secures the
needle within a threaded ring. Some,
however, do not; and the needle is held on the syringe only by friction.
are available in a variety of sizes, ranging from 0.5 ml to 50 ml.
Graduation marks on syringes represent different increments,
depending on the size of the syringe. The
larger the syringe capacity, usually the larger the interval between
graduation lines. For example,
each line on a 10-ml syringe represents 0.2 ml; while on a 30-ml syringe, each
line represents 1 ml. When
measuring with a syringe, the final edge (closest to the tip of the syringe)
of the plunger piston which comes in contact with the syringe barrel should be
lined up to the graduation mark on the barrel which corresponds to the volume
desired. To maintain sterility,
two parts of a syringe may not be touched.
These are the syringe tip and the plunger.
are sent from the manufacturer assembled and individually packaged in paper
overwraps or plastic covers. The
sterility of the contents is guaranteed as long as the outer package remains
intact. Therefore, packages
should be inspected, and any that are damaged should be discarded.
The syringe package should be opened within the laminar flow hood in
order to maintain sterility.
syringes are also packaged with a protector over the syringe tip.
The syringe tip protector should be left in place until ready for
needle attachment. When attaching
needles to Luer-lock type syringes, a quarter-turn is usually sufficient to
secure the needle to the syringe.
syringes, needles are also available in a variety of sizes.
Needle size is designated by two numbers, measuring gauge and length.
The gauge of the needle corresponds to the diameter of the needle's
bore and ranges from 27 (the finest), to 13 (the largest).
(Note that the larger the gauge, the smaller the bore of the needle.)
The length of a needle shaft is measured in inches and usually ranged
from 3/8 to 3 2
needles consist of two parts: the
shaft and the hub (Fig. 5). The
hub is used to attach the needle to the syringe and is often color-coded to
correspond to a specific gauge size. The
tip of the needle shaft is slanted to form a point, with the slant called the
bevel and the point called the bevel tip.
The opposite end of the slant is termed the bevel heel.
are sent from the manufacturer individually packaged in paper and plastic
overwraps. The sterility of the contents is guaranteed as long as the
package remains intact. Therefore,
packages that are damaged should be discarded.
To maintain sterility, the needle package should be opened within the
laminar flow hood.
needle shaft is usually metal and is lubricated with a sterile silicone
coating. For this reason, needles
should never be swabbed with alcohol. no
part of the needle proper should be touched.
Needles should be manipulated by their protective covers only.
The protective cover should be left in place until the needle and/or
syringe is to be used, for example, when withdrawing fluid from a vial or
medications are usually supplied in vials or ampuls, each requiring different
techniques for withdrawal of the medication.
A vial is a glass container with a rubber
stopper secured to its top by an aluminum band.
The rubber stopper is usually protected by a flip-top cap or aluminum
cover. Most protective caps do
not guarantee sterility of the rubber closure.
Therefore, it is necessary, before entry, to spray or swab all vials
with 70% isopropyl alcohol. The
correct swabbing technique is several firm strokes in the same direction over
the rubber closure, always using a clean, unused portion of a swab on each
item. The swabbing is effective
in two ways: first, the alcohol acts as a disinfecting agent; and second, the
physical act of swabbing in one direction removes particles from the vial
problem to be avoided when using vials is the formation of cores, or pieces of
the rubber closure which are carved out as the needle is inserted into the
vial. To prevent core formation,
the needle should be inserted in such a way as to penetrate the rubber closure
at the same point with both the tip and heel of the bevel.
This is accomplished by first piercing the rubber closure with the
bevel tip and then applying lateral (toward the bevel) and downward pressure
to insert the needle (Fig. 6).
are closed-system containers, since air or fluid cannot pass freely in or out
of them. For this reason, to prevent vacuum formation within a vial, it is
usually necessary to replace with air the volume of fluid to be removed from a
vial, so inject a quantity of air equal to the volume of fluid to be removed
from the vial.
the drug within a vial is in powdered form, reconstitution must first be performed.
The desired volume of diluent,
such as sterile water for injection, is added to the vial containing the
powdered drug. As the diluent is added, an equal volume of air must be removed
in order to prevent a positive pressure from developing inside the vial.
This may be accomplished by allowing air to flow into the syringe
before removing the needle from the vial.
Although most drugs dissolve rapidly when shaken, care must be taken to
insure that the drug is completely dissolved before proceeding with further
vials, ampuls are composed entirely of glass, and once broken, become
open-system containers. Since air
or fluid may now pass freely in and out of the container, it is not necessary
to replace with air the volume of fluid to be withdrawn from an ampul.
often have a painted ring, representing either of two things.
A ring on the ampul neck indicates the point at which the ampul should
break. Most ampuls are weakened
by the manufacturer at this point by physical or chemical means.
On the other hand, a ring painted higher on the ampul head indicates
the point behind which fingers should be kept to avoid becoming cut when the
ampul is broken. Regardless of
the location of the stripe, the ampul should always be broken open at the
break an ampul properly, the ampul neck is cleansed with an alcohol swab and,
leaving the swab in place, the ampul is grasped with one hand on each side of
the neck, between the thumb and index finger.
A quick, firm, snapping motion is then exerted away from oneself, as if
breaking a pencil. Ampuls should
not be opened toward the HEPA filter of the laminar flow hood or toward other
sterile products within the hood. If
the ampul does not open easily, it should be rotated slightly so that pressure
is exerted at a weaker point.
withdraw medication from an ampul, the ampul should be tilted and the bevel of
the needle placed in the corner space near the opening.
Surface tension should keep the solution from spilling out of the ampul. The syringe plunger is then pulled back to withdraw the
possibility that glass or paint chips may fall into the solution when an ampul
is broken requires the use of a filter in the preparation process.
Most often, a needle with a 5-micron filter in the hub is used, either
as solution is pulled into or pushed out of the syringe.
Usually, the medication is withdrawn from the ampul with a regular
needle and then the needle is changed to a filter needle before pushing drug
out of the syringe.
admixtures may be prepared in flexible plastic bags, glass bottles, or
semirigid plastic containers. Frequently,
flexible plastic bags made of polyvinyl chloride (PVC) are used which allow
easier storage and, compared to glass bottles, decreased breakage and
elimination of the need to vent the container for fluid removal.
bags are available in several sizes, containing a variety of solutions.
They are supplied in plastic overwraps, which limit fluid loss.
The injection portal of a PVC bag, covered by a protective rubber tip,
should be positioned toward the HEPA filter when preparing an IV admixture.
compounding, all needed materials should be assembled and vials, ampuls, and
IV solution containers visually inspected for signs of cloudiness, particulate
matter, cracks or punctures, past expiration dates, or any other indications
that the product may be defective. Again,
only materials necessary to the preparation process should be placed within
the laminar flow hood.
all injection surfaces should be disinfected, including the injection portal
of the PVC bag. Drug fluid is
withdrawn from its container in the amount needed, using the syringe size
closest to the volume to be injected. To
obtain as accurate a measurement as possible, air bubbles should be removed
from the syringe after first pulling back slightly on the plunger to draw into
the syringe barrel any fluid trapped in the needle.
Ampuls should not be opened toward the HEPA filter of the laminar flow
hood or toward other sterile products within the hood.
If the ampul does not open easily, it should be rotated slightly so
that pressure is exerted at a weaker point.
admixture of drug into a PVC bag is accomplished by inserting a needle into
the injection portal and injecting the appropriate volume of drug fluid.
This injection portal has two diaphragms which must be pierced for
fluid transfer into the IV solution (Fig. 7).
The first diaphragm is the tan, outside latex tip and is followed by
another plastic diaphragm about 3/8 inch inside the injection portal.
Therefore, to assure fluid transfer into the IV bag, a needle longer
than 3/8 inch should be used.
admixture of medication to a glass infusion container is accomplished by first
removing the protective cap from the IV bottle.
A drug additive is then injected through the rubber stopper or latex
diaphragm, either of which should be swabbed with alcohol before entry.
Needles should be inserted through rubber stoppers using the technique
to avoid core formation, as previously described for vials.
Following admixture, a protective seal is placed over the stopper of a
glass container before it is removed from the laminar flow hood.
using a polyolefin, semirigid container for admixture preparation, the protective
screw cap is removed and drug additions are made through the designated
injection portal. Disinfection of
the portal and replacement of a protective cap are not necessary.
an IV admixture or other sterile product is compounded, it should be properly
labeled with the following information:
Patient name and room number
name and volume
Additive name and quantity
Date of preparation
Expiration date and time
Prescribed administration rate
Ancillary precaution labels
final inspection of the admixture for cores and particulates should be
performed. All drug and IV
solution containers used in preparing the admixture should be checked to
verify that the proper amount of the correct drug has been added to the
correct IV solution.
summary, aseptic technique is a means of manipulating sterile products without
contaminating them. Proper use of
the laminar flow hood and strict aseptic technique are the most important
factors in preventing the contamination of sterile products.
Thorough training of personnel in the proper use of the laminar flow
hood and strict aseptic technique, followed by the development of
conscientious work habits, is of utmost importance to any sterile products
obtain continuing education credits, remove the answer sheet from the back of
this study guide and follow the directions for completing the test and
applying for credit.
DIRECTIONS: Blacken the letter on the answer sheet corresponding to the one
best response for each of the following.
The most important requirement in the preparation of sterile products
a properly functioning and certified laminar air flow hood.
a "Class 100" environment with no more than 100 particles per
cubic foot that are 0.5 micron or larger.
the use of strict aseptic technique.
a HEPA filter certified by qualified personnel.
The advantage of using a biological safety cabinet with vertical air
flow for the preparation of antineoplastic (anticancer) drugs is:
the zone of turbulence created behind an object is minimized.
the risk of reflected contamination from the operator's body or
"backwash" is reduced.
the operator is protected from exposure to radiation by a lead shield.
contaminated air is not blown on the operator and into the room.
Sterile objects should be placed and manipulated at least 6 inches
within the hood because:
they are less likely to become contaminated if the operator coughs or
room air may contaminate sterile objects placed close to the front of
air flow is faster deeper in the hood.
air flow is more turbulent deeper in the hood.
The sterile parts of a syringe that may never be touched are:
the barrel and plunger
the barrel and tip
the plunger and tip
the barrel, plunger, and tip
Which of the following numbers represents a gauge size for a large
d. 3 2
Injection surfaces are swabbed with 70% isopropyl alcohol prior to
needle insertion because:
the alcohol acts as a disinfecting agent.
the physical act of swabbing removes particles
the evaporation of alcohol from the injection surface physically removes
both a and b are true.
A needle should be manipulated by its protective cover in order to:
protect the operator from injury
keep it from becoming dull
keep the silicone coating intact
To equalize the pressure inside a vial when removing drug fluid, it is
a quantity of air equal to the volume of fluid to be removed.
shake the vial.
swab the top with 70% isopropyl alcohol.
select the syringe size closest to the volume to be removed.
A filter must be used when preparing an admixture of a drug that comes in
an ampul because:
the ampul is opened, it is an open-system container and can no longer be
glass chips may fall into solution when the ampul is broken.
drugs stored for extended periods in glass ampuls may contain impurities.
drugs that come in ampuls may contain impurities because ampuls cannot be
After compounding, all drug and IV solution containers should be
for cracks, punctures, haziness, cores, and particulates.
to verify that the proper amount of the correct drug has been added to
the correct IV solution.
to verify that the label is accurate.
all of the above are correct.