Can We
Revisit Cataract Surgery Sterile Technique?
Surgeons question whether many of the
recommended protocols are necessary.
BY ROCHELLE
NATALONI, CONTRIBUTING EDITOR
Perioperative sterility
standards exist to protect patients, surgeons and operating
room personnel from potential physical harm. While it seems
that such a basic aim would be immune from criticism, some
ophthalmic surgeons say that, in the case of cataract surgery,
adherence to what are often superfluous protocols is simply
another example of defensive medicine in an overly litigious
society.
Examples of standards that may have
been appropriate in the early days of cataract surgery but are
arguably of limited value today include autoclaving surgical
instruments rather than sterilizing them with the faster flash
technique, and requiring a visitor into an ambulatory surgery
center (ASC) operating room (OR) to don a sterile gown and
booties. Critics pose questions such as: "If flash
sterilization is acceptable in some situations, why isn't it
acceptable in every situation, and is scrubbing prior to
cataract surgery -- where the incision is measured in
millimeters -- equally as crucial as it is prior to general
surgery where the wounds are significantly larger?"
Infection control and sterilization
experts say some facilities flash sterilize single instruments
that have become contaminated; others routinely flash
everything; but most follow protocols that are somewhere in
between. If done correctly, flash sterilization reportedly
meets two crucial surgery parameters: safety and efficiency.
Despite the technique's ability to safely and efficiently do
the job, the Association of Operating Room Nurses' (AORN)
Recommended Practices for Sterilization in the Practice
Setting indicates that flash sterilization should only be used
when there is insufficient time to sterilize an item by the
preferred prepackaged method and only in carefully selected
situations when certain parameters are met. (2004 Standards,
Recommended Practice and Guidelines).
Surgeons also question the
discrepancy between the time needed to sterilize various
instruments and devices because the distinction has a direct
effect on turnaround time. Why is 3 minutes all it takes for
some instruments, while others need to be sterilized for 10
minutes? The simple answer is that porous items take longer to
sterilize. For a more complete explanation, see the
Association for the Advancement of Medical Instrumentation's
(AAMI) report titled Flash Sterilization: Steam Sterilization
of Patient Care Items for Immediate Use (http://www.aami.org/). (See also "Minimum
Flash Sterilization Exposure Times," on the next page.)
As far as pre-op scrubbing,
according to at least
two studies, (J Hosp Infect.
1997 May;36(1):49-65 and British Journal of Ophthal.
2004;88:438-439), waterless alcohol-based gel formulas are
quicker and either as effective or more effective surgical
hand preparations than detergent-based antiseptic.
Another protocol that's often
questioned is the need for rubber gloves during cataract
surgery. "What evidence is there that scrubbing reduces the
risk of endophthalmitis after cataract surgery?" asks Richard
Mackool, M.D., director of Mackool Eye Institute, Astoria,
N.Y. "The answer is that there is none, and I frankly doubt
that such a benefit exists. We wear sterile gloves even though
we hardly ever suture anymore, which essentially negates the
risk of penetrating a glove with a needle during the
procedure, and it's a stretch to imagine a needle could
penetrate a glove without some significant sensory feedback to
the surgeon," says Dr. Mackool. Furthermore, he adds, "The
highly unlikely possibility of penetrating a glove with a
needle has been used to justify scrubbing, and anyone who
believes that scrubbing sterilizes the hands is, in the words
of a Lancet editorial of which I am particularly fond, 'either
a fool or a knave or both.' " Perhaps most important of all,
he says, "The best studies indicate that the source of the
bacteria involved in endophthalmitis is most commonly the
patient's own conjunctival/lid flora anyway."
The Thinking Behind the
Questions
An alphabet soup of associations,
including AORN and AAMI as well as the American Association
for Accreditation of Ambulatory Surgical Facilities (AAAASF),
promulgates practice guidelines to help facilities retain a
sterile OR environment. Some of the guidelines address optimum
equipment sterilization times and techniques, others address
variables such as scrubbing, draping and traffic patterns.
Representatives of these associations are quick to point out
that the guidelines are voluntary, and that they are updated
frequently to take new developments, such as research, into
account. However, while it is true that these guidelines are
voluntary, some form of a guideline is essentially mandatory
because facility credentialing tends to hinge on the adoption
of a protocol designed to protect patients and staff.
The problem, say some
ophthalmologists, is that the guidelines do not differentiate
between specialties, which means that the infection control
and sterility guidelines are essentially the same for cataract
extraction as they are for kidney transplant. As cataract
surgery has distinguished itself from other more invasive
general surgery procedures by evolving into a brief and
minimally invasive technique, the concomitant OR sterility
protocols that ophthalmic surgeons are expected to adhere to
have changed little, if at all.
Los Altos, Calif.-based cataract
surgeon David F. Chang, M.D., says in community hospitals,
standard OR protocols are set up to cover a broad range of
surgeries for all the different specialties, and facility
administrators are reluctant to depart from these protocols
because of liability concerns if they make exceptions.
"If a patient were to go blind from
an infection, then any deviation from standard protocols could
be questioned by a malpractice attorney," says Dr. Chang.
"Whether there is any scientific merit to each step in the
protocol is beside the point. What matters in court is whether
the surgery center did or did not follow 'community
standards.' A lot of this is defensive medicine." Dr. Chang is
a clinical professor of ophthalmology at the University of
California in San Francisco.
"We know from molecular biological
studies that the pathogens that cause infectious post-cataract
endophthalmitis nearly always come from the patients' own
conjunctiva and lids, and that true nosocomial infections are
extremely rare," he continues. "So there are many routine
practices whose value could be questioned, such as full-body
draping of the patient, redraping the instrument table and
regowning the surgical team for each case, the need for
repeated hand washing and so forth. However, because of the
rarity of post-cataract endophthalmitis, it would be difficult
to prove any of this in a randomized trial. We haven't even
been able to scientifically demonstrate whether topical
antibiotic prophylaxis is necessary. Given the speed of
cataract surgery and the small incision size, it would seem
that the risk of nosocomial infection would be much less than
for abdominal or orthopedic surgery."
However, because changing standard
OR practices in the United States would raise medical-legal
concerns, it's more likely that answers will emerge elsewhere.
For instance, says Dr. Chang, in India where there are more
than 10 million blind patients in need of cataract surgery,
cost and efficiency, as opposed to legal concerns, are the
guiding factors. "With a limited budget and a limited number
of surgeons, the number of people that can receive cataract
surgery depends on a facility's ability to do the surgery
rapidly at low cost. To do that they must eliminate all
superfluous practices," he explains.
For example, the Aravind Eye
Hospital System, which comprises five facilities throughout
Southern India, is one of the best international models of how
to perform high-volume, low-cost cataract surgery with
excellent outcomes and low complication rates. "They do more
than 200,000 cataract cases a year, 70% of which are provided
to nonpaying charity patients," says Dr. Chang. "Success on
this scale is accomplished in part because they've made a
science out of streamlining cataract surgery, and achieving
the best possible results while minimizing the cost. Aravind's
endophthalmitis rate is less than one in 1,000, which is
comparable to U.S. surgery centers. At their newest hospital,
they had only one infection in their first 9,000 phaco
cases."
At Aravind, flash sterilization of
surgical instruments is standard; they use the same balanced
salt solution irrigation bottle for multiple patients; four
surgeries are performed simultaneously in the same OR; and at
any given time a dozen patients in their street attire may be
sitting in the OR waiting for their turn to have surgery,
according to Dr. Chang, who has visited Aravind. Rather than
changing their gloves or gowns between cases, the surgical
staff wipe their gloved hands with chlorhexidine solution.
"Despite all of these departures
from our standard protocols, they have shown that the
infection rate is no higher than ours in the U.S.," says Dr.
Chang. "Does that prove that the protocols we rely on are
unnecessary? Absolutely not, but it should give us cause to
consider that a lot of the things that we're doing are
probably adding unnecessarily to the cost of the procedure
either in the form of disposables or in the form of lengthier
delays in our turnaround time," he says.
With less than 1% of the country's
ophthalmic manpower, Aravind performs about 5% of all cataract
surgeries in India. "Here you have a center that's doing huge
volume (up to 400 surgeries a day) and yet is able to
electronically track its results and infection rate very
carefully using custom software. This has allowed them to
confirm that these cost-saving measures are not compromising
care," says Dr. Chang.
What About ASCs?
While surgeons who own ASCs would
be expected to have autonomy in setting their own surgery
sterility protocols, it's often the ASC administrator who sets
the tone. Interestingly, ASC administrators, who are often
former OR nurses, tend to incorporate AORN's voluntary
recommended practices into the ASCs that they run. Because of
the surgeon's personal investment in a free-standing facility,
the specter of litigation might influence practice patterns
here even more than in the hospital setting.
Karl G. Stonecipher, M.D., who
performs all of his surgeries at Southeastern Eye Center, in
Greensboro, N.C., says that budget may have just as much
influence on these types of decisions. While he wonders if
some of the recommended guidelines are based more on tradition
than science, he notes, "When trying to weigh costs vs.
benefits, any defensive medical mode will produce significant
increases in cost."
Paul Koch, M.D., of Koch Eye
Associates in Warwick, R.I., says the one-size-fits-all
recommended guidelines simply don't add up from a practical
standpoint. "When visitors come into the OR, they have to put
on scrubs and booties and a hat and mask, but if a technician
comes in to look at a thermostat, all that's required is that
he put a jumpsuit on over his clothes. It just doesn't make
sense," he says.
According to AORN's Recommended
Practices for Traffic Patterns in the Perioperative Practice
Setting: "Persons in the restricted area [which includes the
OR] are required to wear full surgical attire and cover all
head and facial hair, including sideburns and necklines.
Nonscrubbed personnel should wear long-sleeved jackets that
are buttoned or snapped closed during use. Masks are required
where open sterile supplies or scrubbed persons are located."
It goes on to say, "Persons from other departments (and this
would refer to the technician mentioned earlier) entering the
restricted area of the surgical suite for a brief time for a
specific purpose may don a coverall suit designed to totally
cover outside apparel." The distinction appears to be the
length of time the person is in the OR as well as proximity to
the sterile field and to scrubbed personnel.
Considering the length of time the
average cataract patient is in the OR, and the questionable
value of scrubbing, this distinction could be considered moot.
"There is no authoritative source asking the important
questions because no one wants to go out on a limb and make
these standards less rigorous regardless of the absence of
scientific proof of their worth," says Dr. Koch.
Minimum
Flash Sterilization Exposure
Times |
Sterilizer Type |
Temperature |
Items |
Minimum Time |
Gravity Displacement |
270º F (132º C) |
All Metal, Nonporous, No Lumens |
3 Minutes |
Gravity Displacement |
270º F (132º C) |
Metal Items with Lumens, Porous Items* |
10 Minutes |
Pre-Vacuum |
270º F (132º C) |
All Metal, Nonporous, No Lumens |
3 minutes |
Pre-Vacuum |
270 F (132 C) |
Metal Items with Lumens, Porous Items* |
4 minutes |
* Porous items are those made of
rubber, plastic, etc.
Source: Association for the
Advancement of Medical
Instrumentation |