Session VIII - Basic Science

Fri., 10/6/06 Basic Science, Paper #48, 4:48 pm

Comparison of Pulse Lavage versus Bulb Syringe Irrigation in a Chronic Contaminated Wound Model

Brett D. Owens, MD (n); Daniel W. White, MD (n); Joseph C. Wenke, PhD (n);
US Army Institute of Surgical Research, Fort Sam Houston, Texas, USA

Purpose: Little is known of the effectiveness of different methods currently used for irrigation of open fractures and wounds. While pulse lavage has been shown to be more effective than bulb syringe irrigation in removing bacteria in an acute model, the purpose of this study was to compare these two devices in a chronic animal model.

Methods: We used an established model involving the creation of a reproducible complex orthopaedic wound with injury to muscle, fascia, periosteum, and bone followed by inoculation with a Pseudomonas aeruginosa (lux) bacteria. This genetically altered bacterium luminesces in the wound, providing the ability for quantitative analysis with a photon-counting camera system. Six hours after the injury/inoculation, an irrigation and debridement was performed. 24 goats were randomized into two treatment groups: bulb syringe (9 liters normal saline) and pulse lavage (6 liters normal saline). Groups received different volumes in an effort to have similar postirrigation bacterial levels, based upon previous work with this model. Images were obtained immediately before, immediately after, and 48 hours after treatment. Relative luminescent units (RLUs) were calculated at each time point. Preplanned orthogonal contrasts between the two treatments at each time point were conducted. Statistical significance was determined as p < 0.05.

Results:

Mean RLU 105 ± SEM

 Treatment Group  Pre-irrigation  Post-irrigation  48 hrs Post-irrigation
 Bulb  6.21 ± 0.21  1.59 ± 0.09  2.62 ± 0.10
 Pulse  6.73 ± 0.27  2.05 ± 0.13  5.02 ± 0.24
 P-value   P=0.57   P=0.70  P=0.02

While both treatments were effective in removing similar amounts of the bacteria initially (69% and 74%), the bacterial levels in the pulse lavage group rebounded to 94% of the original level at 48 hours. The bulb syringe group rebounded to 48% of the original level, which is significantly (P = 0.02) lower than the pulse lavage group.

Conclusion/Significance: While pulse lavage has been shown to be more efficient at bacterial removal, our model demonstrated a rebound in bacterial counts at 48 hours. This rebound in bacterial growth could be caused by damaging effects on host tissue by the pulse lavage system. Although irrigation with bulb syringe can require greater solution volume to achieve the same initial bacterial removal, this device may be superior for the irrigation of contaminated wounds.

If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
· The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an "off label" use). · · FDA information not available at time of printing.