Volume 90, Issue 10 , Pages 1723-1726, October 2009
Is the Use of Low-Pressure Pulsatile Lavage for Pressure Ulcer Management Associated With Environmental Contamination With Acinetobacter baumannii?
Article Outline
Abstract
Ho CH, Johnson T, Miklacic J, Donskey CJ. Is the use of low-pressure pulsatile lavage for pressure ulcer management associated with environmental contamination with Acinetobacter baumannii?
Objective
To determine the extent of environmental contamination associated with low-pressure pulsatile lavage of stage III or IV pressure ulcers in patients with spinal cord injury (SCI) when routine infection control precautions are used for wounds colonized or infected with Acinetobacter baumannii.
Design
Prospective investigation in which pressure ulcer cultures and environmental cultures were obtained before and after low-pressure pulsatile lavage treatment, and before and after regular dressing changes. Environmental cultures included the patient's bedrail and settle plates placed 0.6, 1.5, and 2.4m from the wound to assess airborne spread of A. baumannii.
Setting
SCI inpatient unit in a Department of Veterans Affairs Medical Center.
Participants
Inpatients (N=15) with SCI receiving daily low-pressure pulsatile lavage treatment for stage III or IV pressure ulcers with standard dressing change, as well as regular dressing changes without low-pressure pulsatile lavage at other times of the day.
Interventions
Standard, regular dressing changes and dressing changes with low-pressure pulsatile lavage.
Main Outcome Measures
Comparison of frequency of environmental contamination with A. baumannii associated with low-pressure pulsatile lavage versus regular dressing changes.
Results
Of the 15 SCI inpatients meeting inclusion criteria, 9 (60%) grew A. baumannii from their wounds. Of the 9 patients with wound cultures positive for A. baumannii, only 1 (11%) had environmental contamination with this organism after performance of low-pressure pulsatile lavage, and the same patient had environmental contamination after a standard dressing change. The antibiotic susceptibility patterns of the wound and environmental A. baumannii isolates were identical.
Conclusions
Low-pressure pulsatile lavage using the infection control methods described is not associated with an increased rate of environmental contamination of A. baumannii in comparison with standard dressing changes.
Key Words: Hydrotherapy, Infection control, Irrigation, Pressure ulcer, Rehabilitation, Spinal cord injuries
List of Abbreviations: psi, pounds per square inch, SCI, spinal cord injury
RECENT DATA FROM the National Institute on Disability and Rehabilitation Research Model Spinal Cord Injury System indicate that pressure ulcers remain one of the most prevalent causes of long-term morbidity in patients with SCI and are the leading cause of hospitalization among this population.1 This is of particular relevance in the care of persons with SCI, because their limited mobility and independence are further inhibited when pressure ulcers arise. Significant limitations in the person's ability to participate in normal activities of daily living, an active rehabilitation program, or both, may occur. Furthermore, the presence of pressure ulcers can lead to secondary medical complications, such as local soft tissue infections, osteomyelitis, or more severe systemic problems such as sepsis.1 Therefore, the prompt and effective treatment of pressure ulcers for persons with SCI is of paramount importance. Any treatment modality that can help to relieve the problem is to be considered seriously and thoroughly. Many options of treatment are available for pressure ulcers; however, clinical practice guidelines from the Agency for Health Care Policy and Research specifically recommend the use of 2 specialized treatment modalities to enhance wound healing. Hydrotherapy is one of them.2
Pulsatile lavage therapy provides direct, localized hydrotherapy to pressure ulcers by using a pulsatile, pressurized stream of sterile normal saline. This technique is widely accepted in the orthopedic field for soft tissues injuries, infections, and open fractures during surgery.3, 4, 5 It has been recommended that low-pressure lavage is a better option than high-pressure lavage for soft tissue that is contaminated with bacteria because high-pressure lavage can cause the bacteria to penetrate deeper into the soft tissue, resulting in greater bacterial retention.4, 5 Generally, low pressure can be defined as a flow between 4 and 15psi. In our previous clinical experience with low-pressure pulsatile lavage, we have found that the technique is simple for the clinician to use and well tolerated by patients. Because of these benefits, it has been used for wound care at the Louis Stokes Cleveland Department of Veterans Affairs Medical Center for many years. The clinical experience on the SCI/disorders unit at this facility has been positive, without any known significant complication to the patients receiving the treatment.
However, a recent study by Maragakis et al6 at the Johns Hopkins Hospital described an outbreak of multidrug-resistant Acinetobacter baumannii associated with pulsatile lavage wound treatment. This retrospective case-control study demonstrated that pulsatile lavage was a significant risk factor for acquisition of the A. baumannii strain. Multiple environmental surfaces in the pulsatile lavage procedure room were found to be contaminated with the outbreak strain. Therefore, the authors hypothesized that dissemination occurred during the pulsatile lavage procedures. Several potential factors that may have contributed to the outbreak were identified, including allowing disposable suction canister inserts to fill rather than changing them between patients; simultaneous treatment of patients on adjacent stretchers; open supply shelves, which made cleaning and disinfection difficult; and high room humidity. Based on their findings, the authors made several recommendations for infection control procedures to prevent similar outbreaks. These included having health care workers performing pulsatile lavage use personal protective equipment and wear surgical masks, having intravenous lines and wounds covered, restriction of pulsatile lavage to private rooms with easily washable surfaces and no open supply shelves, and thorough cleaning and disinfection of the room after each procedure and at the end of the day. After publication of the report by Maragakis,6 others have also recommended that enhanced infection control measures be implemented to prevent transmission of pathogens during pulsatile lavage.7
The aim of the present study was to investigate the potential for transmission of A. baumannii during low-pressure pulsatile lavage in our institution where the infection control procedures recommended by Maragakis6 were followed. We compared the extent of environmental contamination with A. baumannii during the care of contaminated pressure ulcers with low-pressure pulsatile lavage versus standard dressing changes. Our hypothesis was that low-pressure pulsatile lavage of pressure ulcers would be associated with increased rates of environmental contamination in comparison with pressure ulcer care that did not involve low-pressure pulsatile lavage.
Methods
We performed a prospective study of 16 inpatients with SCI receiving low-pressure pulsatile lavage as a part of their standard stage III or IV pelvic pressure ulcer treatment. For each patient, the culture procedures to assess environmental contamination were conducted during an episode of low-pressure pulsatile lavage and a second episode of standard wound care treatment without low-pressure pulsatile lavage. The study was approved by the local institutional review board, and informed consent was obtained from all the subjects.
Low-Pressure Pulsatile Lavage Protocol
As part of their routine wound care regimen, each of the study subjects received 2 to 3 dressing changes a day. Low-pressure pulsatile lavage was only performed once daily in conjunction with the morning dressing changes. The dressing changes followed the recommendations by the Consortium for Spinal Cord Medicine Clinical Practice Guidelines for the treatment of pressure ulcers.8 The typical treatment procedure for low-pressure pulsatile lavage used at our institution was followed for all the patients in the study group. The infection control protocol included the recommendations made by Maragakis6 and others7, including replacement of disposable suction canister inserts after each procedure, appropriate use of a splash shield to contain splashes, maintenance of close proximity of the suction tip with the wound bed during the procedure, having health care workers who perform low-pressure pulsatile lavage use personal protective equipment (ie, gowns, gloves, surgical masks, goggles), covering intravenous lines and wounds, restriction of pulsatile lavage to private rooms with easily washable surfaces and no open supply shelves, and adequate training of staff regarding infection control measures.
The same type of low-pressure pulsatile lavage systema was used for all the patients. This portable hydrotherapy system delivers a water pressure of less than 15psi through its fan spray tip. One liter of sterile normal saline at room temperature was used for low-pressure pulsatile lavage treatment of each wound. The duration of the treatment varied depending on the time required to use the liter of saline and the characteristics of the wound. Patients were positioned either lying face down or on their side, depending on the location of the ulcer. The low-pressure pulsatile lavage device was for single-patient use only. Furthermore, the low-pressure pulsatile lavage fan spray tip was changed between treatments, and a new suction canister was used for each treatment. All the low-pressure pulsatile lavage treatments were performed at the individual patient's bedside.
Evaluation of Environmental Contamination
The study procedures included wound cultures, environmental surface cultures, and “settle plate” cultures to determine whether bacteria were spread through the air as an aerosol. All study procedures were performed by the same research nurse, while the pressure ulcer treatments (including low-pressure pulsatile lavage and standard dressing changes) were performed by the clinical nurses. At the initial visit, the research nurse swabbed the wound with a sterile cotton-tipped swab before low-pressure pulsatile lavage treatment. The bedside table and the bedrail on the side where the treatment would be done were then disinfected with a 10% bleach solution. The bleach solution was allowed to air dry, and the surfaces were then wiped with paper towels moistened with sterile water to remove any residual bleach. Before and after completion of low-pressure pulsatile lavage, cultures of the bedside table and the bedrail were obtained by applying sterile cotton-tipped swabs premoistened with sterile saline to standardized 5 × 5-cm surface areas. Nonselective plates containing tryptic soy agar with 5% sheep blood (diameter, 100mm) were placed at 0.6, 1.5, and 2.4m from the wound before beginning low-pressure pulsatile lavage and were collected after the procedure was completed. The 0.6- and 1.5-m foot plates were set on the bed, while the 2.4-m foot plate was set on the floor at the end of the bed. For each patient enrolled, a second set of identical cultures was obtained in the evening before and after standard wound care with dressing change; the timing of the second set of cultures was not standardized between patients, but typically evening cultures were collected 8 to 10 hours after low-pressure pulsatile lavage therapy. We speculated that positive cultures from the bedside table and the bedrail after standard dressing changes or low-pressure pulsatile lavage could be due to direct contamination from the wound, should the same bacteria be found in both the wound and these areas. On the other hand, positive cultures from the settle plates after low-pressure pulsatile lavage may be due to contamination by aerosolization from the wound during the treatment, should the same bacteria be found in both the wound and the settle plates.
Data Analysis
The clinical microbiology laboratory evaluated the cultures for Acinetobacter species in accordance with Clinical and Laboratory Standards Institute9 guidelines. Chart review was performed at the time the cultures were taken to determine the demographic characteristics of the patients, medications used, characteristics of the wound, and previous results of wound cultures taken for clinical management reasons. Chart review was again performed 2 to 3 months after the cultures were collected to identify findings of any subsequent clinical cultures and to determine whether wound infections had occurred.
Results
Sixteen SCI inpatients with stage III or IV pressure ulcers met inclusion criteria. Of these 16 subjects, 1 was disqualified because of being discharged before the study was completed. Of the 15 remaining subjects, 9 (60%) had positive cultures for A. baumannii from their wounds. One of these 9 patients also had a positive culture for Pseudomonas aeruginosa from the pressure ulcer. None of the patients had an active infection of their wounds at the time of the study. No significant infectious disease issues regarding the pressure ulcers were identified from the chart review 2 to 3 months after the wound cultures were taken for the study.
All environment surface cultures obtained before low-pressure pulsatile lavage therapy or standard wound care were negative. For the 6 subjects whose wound cultures were negative for Acinetobacter, all environment and settle plate cultures after low-pressure pulsatile lavage were negative for these organisms. Table 1 shows the results of the environmental cultures for the 9 subjects with wound cultures positive for Acinetobacter species. Of these 9 subjects, only 1 (11%) had contamination with A. baumannii after performance of low-pressure pulsatile lavage. For this patient, the wound grew heavy A. baumannii, and an isolate with an identical antibiotic susceptibility pattern was recovered from the 0.6-m settle plate. Notably, the same patient also had environmental contamination with A. baumannii on the 2.4-m settle plate and on the bedrail after standard wound care and dressing change (see table 1).
Table 1. Frequency and Amount of Environmental Contamination With A. baumannii After Low-Pressure Pulsatile Lavage Versus Standard Dressing Changes for 9 Study Subjects With A. baumannii Colonization or Infection of Pressure Ulcers
| Procedure | Culture Site | ||||
|---|---|---|---|---|---|
| Bedrail Before Procedure | Bedrail After Procedure | 0.6-m Settle Plate | 1.5-m Settle Plate | 2.4-m Settle Plate | |
| Pulsatile lavage | 0 (0%) | 0(0%) | 1 (11%)(5 colonies recovered) | 0(0%) | 0(0%) |
| Standard dressing change | 0(0%) | 1 (11%)(30 colonies recovered) | 0(0%) | 0(0%) | 1 (11%)(2 colonies recovered) |
Discussion
The results of our study showed that only 1 (11%) of 9 patients with wounds colonized with Acinetobacter species had environmental contamination with this organism during low-pressure pulsatile lavage therapy. The contamination was present on a settle plate, suggesting aerosolization during the procedure. Our findings suggest that the frequency of environmental contamination during low-pressure pulsatile lavage is relatively low when infection control procedures are followed. These results are consistent with the recommendations made by Maragakis et al,6 who identified a number of factors that may have contributed to an outbreak of multidrug-resistant A. baumannii associated with pulsatile lavage and made several recommendations for infection control procedures to prevent similar outbreaks.
While many health care facilities have instituted infection control measures to limit the spread of resistant bacteria during low-pressure pulsatile lavage, less stringent infection control measures may be followed during standard wound care and dressing changes. The patient who had environmental contamination with Acinetobacter species during low-pressure pulsatile lavage also had contamination of a bedrail and settle plate during standard wound care and dressing change, demonstrating that there is also a risk for environmental contamination during standard pressure ulcer care. Therefore, the findings of our study suggest that some of the infection control measures that are recommended for low-pressure pulsatile lavage therapy may also be indicated when standard dressing changes are performed on stage III or IV pressure ulcers that are colonized or infected with multiresistant bacteria. For example, disinfection of the environment after dressing changes would be a simple measure to reduce the likelihood of transmission of pathogenic organisms that are shed onto surfaces.
Study Limitations
Our study has several limitations. First, the major limitation of our prospective investigation is the small sample size. Additional studies with larger numbers of patients are indicated. Second, only one organism, A. baumannii, was studied. Future studies are needed to examine the potential for transmission of other pathogens such as methicillin-resistant Staphylococcus aureus. Third, molecular typing was not performed to confirm that the environmental and wound strains were identical. However, the fact that environmental cultures were all negative before the procedures suggests that the postprocedure strains originated from the patient's wounds. Furthermore, the wound and environmental isolates had identical susceptibility patterns. Finally, the research nurse interacted with the clinical nurses performing low-pressure pulsatile lavage or standard wound care. Therefore, it is possible that infection control measures were improved during the course of the study and that our findings underestimated the true potential for contamination during low-pressure pulsatile lavage and standard wound care.
Conclusions
We found that the frequency of environmental contamination was low during low-pressure pulsatile lavage treatment of wounds colonized with Acinetobacter species when infection control practices were followed. Our findings support the use of infection control procedures that have been recommended to minimize the risk for transmission of Acinetobacter species during pulsatile lavage.
Supplier
References
- . Medical complications during acute rehabilitation following spinal cord injury: current experience of the model system. Arch Phys Med Rehabil. 1999;80:1397–1401
- Treatment of pressure ulcers (Clinical practice guideline No. 15). Rockville: Dept of Health and Human Services, Agency for Health Care Policy and Research; 1994;AHCPR Publication No. 95-0652
- . A technique for reducing splash exposure during pulsatile lavage. J Orthop Trauma. 2004;18:41–42
- . High-pressure lavage propagates bacteria into soft tissue. Clin Orthop Relat Res. 2005;439:27–31
- . Comparison of bulb syringe and pulsed lavage irrigation with use of bioluminescent musculoskeletal wound model. J Bone Joint Surg Am. 2006;88:2167–2174
- An outbreak of multidrug-resistant Acinetobacter baumannii associated with pulsatile lavage wound treatment. JAMA. 2004;292:3006–3011
- . Wound care equipment linked to Acinetobacter outbreak. Infect Dis News 2005 Feb 1. http://www.infectiousdiseasenews.com/200502/tools.aspAccessed June 8, 2009
- . Pressure ulcer prevention and treatment following spinal cord injury: a clinical practice guideline for health care professionals. Washington (DC): Paralyzed Veterans of America; 2000;
- . Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically: approved standard, M7. Wayne: National Committee for Clinical Laboratory Standards; 1993;
- a Stryker InterPulse System; Stryker, 2825 Airview Blvd, Kalamazoo, MI 49002.
Supported by the Department of Veterans Affairs Rehabilitation Research and Development Service (grant no. A2803R).
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
PII: S0003-9993(09)00373-6
doi:10.1016/j.apmr.2009.04.009
Published by Elsevier Inc.
Volume 90, Issue 10 , Pages 1723-1726, October 2009
