Infection control experts at The Johns Hopkins
Hospital say tighter rules governing use of a hand-held,
high-pressure, water-pumping tool to wash and clean wounds
should be adopted to improve the safety of wound care.
The Johns Hopkins finding comes in response to the
investigation of an outbreak of the antimicrobial resistant
bacterium Acinetobacter baumannii at JHH during a two-month
period in 2003. The organism infected 11 patients and was
traced back to use of pulsatile lavage equipment for wound
care. Three of these patients required admission to the
intensive care unit for sepsis and respiratory distress.
In the future, staff using the water-gun like
equipment will have to wear masks, gowns and gloves during
procedures, which must now be performed in private
treatment rooms that are fully disinfected between patients
to reduce the chances of cross contamination between
patients and staff.
As an added response, the United States Food and Drug
Administration, which supervises device safety, along with
a leading manufacturer of the device, have agreed to change
the product's labeling to include use of routine infection
Johns Hopkins already has instituted the new infection
"Changes at Hopkins and results of the study should
change the way this common procedure is performed at other
acute-care hospitals and long-term care facilities," said
senior study investigator and hospital epidemiologist Trish
Perl, an associate professor of
pathology at the Johns Hopkins School of Medicine.
The Johns Hopkins case study is believed to be the
first investigation to relate an outbreak of this bacterium
to the pulsatile lavage device, and its results are
published in the edition of the Journal of the American
Medical Association online Dec. 22.
The Johns Hopkins investigative team traced the
infection to the pulsatile lavage tool made by Bard-Davol
and determined that the equipment sprayed the potentially
dangerous bacteria into the air and onto surfaces in an
open treatment room, with other patients nearby.
"This was true even though staff correctly followed
procedures for its use," Perl said. "Germs were spread when
patients and staff came in close contact with each other
during procedures and possibly when fewer equipment parts
were changed between patients. Guidelines for its use also
applied only to health care workers, not to patients, prior
to the outbreak."
Since finding the cause of the outbreak at Hopkins,
the specific strain of the bacterium involved in the
outbreak has not reappeared, even after 11 months of
"Antimicrobial resistance is a growing problem for
patient safety in health care settings, such as hospitals
and long-term care facilities, because traditional drugs
are not effective for treating these infections,
particularly among vulnerable groups of sick and elderly
patients," Perl noted. "To solve the problem, we are
increasingly forced to rely on our basic tools of
scientific investigation: finding the initial contact
point, or source, of infection and putting in place the
necessary steps to prevent an outbreak from happening in
the first place."
The investigation began with an immediate review of
medical records after an initial cluster of five patients
became infected with the bacteria, a fivefold increase from
previous months for rates of hospital-based infections.
Culture results from patient samples of blood, sputum,
urine and wounds also were reviewed. Specific samples, or
isolates, of Acinetobacter were analyzed using pulsed-field
gel electrophoresis to determine and track the spread of
the specific strain of the bacterium involved in the
The records helped the researchers identify common
treatments and other links between the infected patients.
Of the five patients in the original cluster, one patient
had a different strain of the bacterium, and had it upon
admission, indicating that the infection was not picked up
at the hospital and removing it from the investigation of
hospital-based cases. Of the remaining four patients,
records showed that three had undergone pulsatile lavage
Subsequent culture testing of the open-space treatment
room for performing the procedure showed widespread
presence of A. baumannii-on the disposable parts of the
pulsatile lavage gun, including disposable tubing and
suction canister, as well as on cleaned stretchers, the
sink and nearby supply shelves.
Further surveillance and testing of 58 patients who
had undergone wound therapy in the same procedure room as
the initial patients showed that six more patients were
infected, and five of these had received pulsatile lavage
By studying patients who had wounds but no infection
with Acinetobacter as a control group, and comparing
possible risk factors for developing infection, the
researchers were able to confirm that pulsatile lavage
treatment was a significant risk factor for the infection.
Patients who had pulsatile lavage treatment were more than
30 times more likely to have infection than patients who
were not treated with pulsatile lavage.
Prior residence in a long-term-care facility was also
a significant risk factor, though no one facility was
implicated, and it was unclear how this contributed to the
outbreak. All other possible risk factors, including
mechanical ventilation and administration of antimicrobial
agents, were not found to be statistically significant.
Further investigation revealed that a change in the
pulsatile lavage procedure had occurred two months prior to
the outbreak. As a cost-saving measure, the disposable
suction canisters for the guns were replaced daily or when
full, rather than between each patient.
"This case study shows the importance of infection
control precautions when introducing a new technology or
procedure for use in the health care setting," said the
study's lead author, Lisa Maragakis, M.D., a clinical
fellow at Hopkins. "Pulsatile lavage is used for wound care
in a variety of settings. We want to make sure that those
who perform the procedure know about the appropriate
infection control precautions to prevent outbreaks of
Acinetobacter or other antimicrobial resistant bacteria,
such as Pseudomonas, which is also a growing problem."
Originally designed in the 1960s for use in the
operating room, pulsatile lavage has been in wider use
since the 1980s. Physical therapists and nurses most
commonly perform the procedure, where sterile saline is
flushed over a wound. A plastic shield prevents splashing,
and another tube is used to suck water containing wound
debris into a canister. The tubing and shield devices are
disposable and not reused between patients. Approximately
3,000 pulsatile lavage procedures are performed annually at
The emergence of multidrug-resistant A. baumannii is a
worldwide phenomenon, with numerous hospital outbreaks each
year. It can lead to potentially fatal infections, such as
ventilator-associated pneumonia, bloodstream infections and
wound infections. The resilient organism can survive on
environmental surfaces for months, making attempts to
control and prevent it more difficult.
Funding for the study was provided by Johns Hopkins
and the U.S. Centers for Disease Control and Prevention.
Other researchers involved in this study were Sara
Cosgrove, Xiaoyan Song, Denny Kim, Patricia Rosenbaum,
Nancy Ciesla, Arjun Srinivasan, Tracy Ross and Karen