In vitro efficacy testing of a novel high-pressure wound irrigator

1534 Correspondence / American Journal of Emergency Medicine 33 (2015) 15151535

  1. Winkel RR, Kalhauge A, Fredfeldt K-E. The usefulness of ultrasound colour-Doppler twinkling artefact for detecting urolithiasis compared with low dose nonenhanced computerized tomography. Ultrasound Med Biol 2012;38(7):1180-7.
  2. Bomann S, Seman M, Sutijono D, Rogers B. Bladder bulge: unifying old and new sonographic bladder wall abnormalities in ureterolithiasis. WestJEM 2012;13(6): 517-23.
  3. Deyoe LA, Cronan JJ, Breslaw BH, Ridlen MS. New techniques of ultrasound and color Doppler in the prospective evaluation of acute renal obstruction. Do they replace the intravenous urogram? Abdom Imaging 1995;20(1):58-63.
  4. Smith-Bindman R, Aubin C, Bailitz J, Bengiamin RN, Camargo Jr CA, Corbo J, et al. Ul- trasonography versus computed tomography for suspected nephrolithiasis. N Engl J Med 2014;371(12):1100-10.
  5. Reed MJ, Cheung L-T. Emergency department led emergency ultrasound may im-

prove the time to diagnosis in patients presenting with a ruptured abdominal aortic aneurysm. Eur J Emerg Med 2014;21(4):272-5.

  1. Thamburaj R, Sivitz A. Does the use of bedside pelvic ultrasound decrease length of stay in the emergency department? Pediatr Emerg Care 2013;29(1):67-70.
  2. Melniker LA, Leibner E, McKenney MG, Lopez P, Briggs WM, Mancuso CA. Random- ized controlled clinical trial of point-of-care, limited ultrasonography for trauma in the emergency department: the first sonography outcomes assessment program trial. Ann Emerg Med 2006;48(3):227-35.
  3. Theodoro D, Blaivas M, Duggal S, Snyder G, Lucas M. Real-time B-mode ultrasound in the ED saves time in the diagnosis of Deep vein thrombosis . Am J Emerg Med 2004;22(3):197-200.
  4. Rodgerson JD, Heegaard WG, Plummer D, Hicks J, Clinton J, Sterner S. Emergency de-

partment right upper quadrant ultrasound is associated with a reduced time to diagno- sis and treatment of ruptured ectopic pregnancies. Acad Emerg Med 2001;8(4):331-6.

  1. Blaivas M, Harwood RA, Lambert MJ. Decreasing length of stay with emergency ul- trasound examination of the gallbladder. Acad Emerg Med 1999;6(10):1020-3.
  2. Blaivas M, Sierzenski P, Plecque D, Lambert M. Do emergency physicians save time when locating a live Intrauterine pregnancy with bedside ultrasonography? Acad Emerg Med 2000;7(9):988-93.
  3. Cohen JS, Teach SJ, Chapman JI. Bedside ultrasound education in pediatric emergency medicine fellowship programs in the United States. Pediatr Emerg Care 2012;28(9): 845-50.

In vitro efficacy testing of a novel high-pressure wound irrigator?

To the Editor,

The incidence of traumatic skin injuries in the United States is esti- mated to range from 4 to 14 million emergency department (ED) visits per year [1]. Such cases often present late after transport delays or long ED wait times, and delays beyond 6 hours foster continual propagation of the residing bacterial population [2]. Effective treatment of these wounds therefore requires the successful removal of colonizing bacteria, and saline irrigation can substantially improve the clinical outcome of even the most contaminated wounds [3]. Furthermore, inadequate irrigation before wound closure elevates the risk of secondary infections. Slow healing and even dehiscence, due to an overwhelmed immune response and poor tissue perfusion, characterize Wound infections resulting from inadequate debridement and irrigation. Furthermore, such infections are difficult to treat due to the broad spectrum of bacterial species that can colonize a wound and the emergence of antibiotic resis- tant strains [4]. Wound infections are associated with complications that range from superficial dehiscence to full thickness soft tissue loss, with subdermal infections requiring hospitalization, surgical intervention, and even amputation [4]. Such complications cost the United States more than $2 billion per year [5], and so improved irrigation and debride- ment techniques are needed to eradicate infections before they manifest. However, a paucity of research in this area has meant that no criterion standard of irrigation saline quantity and pressure has been established to achieve maximal bacterial clearance. Indeed, although higher pressure irrigation systems have been demonstrated to clean wounds more effec- tively [5,6], most EDs continue to rely on syringe delivery systems with a maximal pressure output of 15 to 40 psi [7]. In the present study, we evaluated the effectiveness of the newly developed high-pressure Mav-

? Conflict of interest: The study was designed, performed, and interpreted by EKC and IM who have no actual or potential conflict of interest.

Rik saline irrigation device (Centurion Medical Products, Williamston, MI) in a reductionist contaminated wound model.

Boneless, skinless, broiler chicken breast fillets (Pectoralis major) and autoclaved soil were UV sterilized for 30 minutes be- fore experimentation. To standardize the bacterial load delivered to each chicken breast fillet, soil was inoculated with 1 x 106 colony-forming unit/mL of Staphylococcus aureus. S aureus was se- lected for use, as this agent is the principle causative agent of 90% of ED wound infections [8-11]. A 5-cm laceration was made in each fillet (n = 6). and bacteria-inoculated soil (2 g) was rubbed into each incision. Inoculated fillets were then incubated for 2 hours at 37?C to simulate the average postinjury patient wait time, before division of each into 2 equal parts. One part was im- mediately homogenized in 10 mL sterile saline and served as the unwashed control, whereas the other half was washed with 250 mL of sterile saline, which was delivered by either the Mav-Rik ir- rigator (n = 3) or a standard 60 mL syringe equipped with a splashguard (n = 3) before homogenization. Clinicians commonly attach a splashguard to an irrigation syringe, as the narrowed opening of this de- vice allows for the generation of greater contact pressure. Varying dilu- tions of the tissue homogenates from the unwashed, Mav-Rik-washed, and syringe-washed groups were inoculated into sterile Luria broth and incubated for 18 hours at 37?C in a bacterial shaker. This incubation period allowed the quantification of bacterial burden by spectrophotometry at an absorbance of 600 nm (Gene Spec III; Hitachi Solutions America, San Bruno CA) and is relevant to a clinical setting because irrigation typically precedes wound closure.

As shown in Figure A, Mav-Rik irrigator use significantly reduced the bacterial burden in infected poultry breast fillets from levels seen in matched unwashed tissue (P b .05). In contrast, the delivery of an equal volume of saline with a syringe with splashguard not only failed to reduce bacterial loads; it actually elevated the number of recoverable bacteria compared with matched unwashed tissue (Figure A). On average, Mav-Rik irrigation led to a 14.0% decrease in bacterial load, whereas conventional syringe with splashguard washing led to an 11.5% increase, a 25.5% difference (P b .05) in cleaning efficacy (Figure B). Similar results were obtained in exper- iments in which Mav-Rik irrigation was compared with washing with a conventional syringe without a splashguard (data not shown).

Although both Mav-Rik and syringe methods would be anticipated to reduce the number of bacteria in our simulated wound model, the increased bacterial burden observed after syringe irrigation could be at- tributable to insufficient pressure generated by this method. Rather than removing debris and effective cleaning, syringe saline delivery merely moves the debris within the wound, allowing deeper bacterial infiltration. These wound contaminants then rapidly multiply when incubated under optimal growth conditions before quantification. In contrast, saline delivered by the more uniform high-pressure Mav-Rik system removes more contamination.

Overall, our preliminary experiments suggest that the Mav-Rik irriga- tor is superior to presently used techniques and provides a compelling basis for future studies in more complex wound models that include intact acute immune responses.

Emma K. Crill, MS Ian Marriott, PhD*

Department of Biology, University of North Carolina at Charlotte

Charlotte, NC 28223

*Corresponding author. Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, NC 28223

Tel.: 704-687-8506, fax: 704-687-1488

E-mail addresses: [email protected], [email protected] http://dx.doi.org/10.1016/j.ajem.2015.05.044

Correspondence / American Journal of Emergency Medicine 33 (2015) 15151535



Figure. The Mav-Rik irrigator significantly reduces bacterial burden in a poultry breast fillet model of wound infection compared with a conventional syringe fitted with splashguard. A, Bacterial concentration in lacerated tissue inoculated with soil containing S aureus (1 x 106 colony-forming unit/mL) for 2 hours before tissue homogenization and determination of total bacterial numbers in matched unwashed tissue (before) or tissue washed with 250 mL of sterile saline (after) using the Mav-Rik or a 60-mL syringe with a splashguard, after 18-hour incubation in bacterial growth media and spectrophotometry at an absor- bance of 600 nm. B, Relative percentage reductions in bacterial burden in infected tissue after washing using the Mav-Rik or conventional syringe derived from the data presented in panel A. Results are presented as the mean +- SEM and were tested statistically by Student t test or 1-way analysis of variance with Tukey post hoc test as appropriate using commercially available software (Prism; GraphPad Software Inc, La Jolla, CA). Asterisks indicate a significant difference between Mav-Rik and syringe groups (n = 3, P b .05).

  1. Singer AJ, Dagum AB. Current management of acute cutaneous wounds. N Engl J Med 2008;359:1037-46.
  2. Nicks BA, Ayello EA, Woo K, Nitzki-George D, Sibbald RG. Acute Wound management:

revisiting the approach to assessment, irrigation, and closure considerations. Int J Emerg Med 2010;3:399-407.

  1. Berk WA, Welch RD, Bock BF. Controversial issues in clinical management of the

simple wound. Ann Emerg Med 1992;21:72-80.

  1. Nichols RL, Florman S. Clinical presentations of soft-tissue infections and surgical site infections. Clin Infect Dis 2001;33:S84-93.
  2. Hollander JE, Singer AJ. Laceration management. Ann Emerg Med 1999;34:


  1. Svoboda SJ, Bice TG, Gooden HA, Brooks DE, Thomas DB, Wenke JC. Com- parison of bulb syringe and pulsed lavage irrigation with use of a biolu- minescent musculoskeletal wound model. J Bone Joint Surg Am 2006;88: 2167-74.
  2. Singer AJ, Hollander JE, Subramanian S, Malhotra AK, Villez PA. Pressure dynamics of various irrigation techniques commonly used in the emergency department. Ann Emerg Med 1994;24:36-40.
  3. Moran GJ, Krishnadasan A, Gorwitz RJ, Fosheim GE, McDougal LK, Carey RB, et al. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med 2006;355:666-74.
  4. Centers for Disease Control and Prevention (CDC). Invasive methicillin-resistant Staphylococcus aureus infections among dialysis patients–United States, 2005. MMWR Morb Mortal Wkly Rep 2007;56:197-9.
  5. Klevens RM, Morrison MA, Nadle J, Petit S, Gershman K, Ray S, et al. Invasive methicillin-resistant Staphylococcus aureus infections in the United States. JAMA 2007;298:1763-71.
  6. Jones TF, Creech CB, Erwin P, Baird SG, Woron AM, Schaffner W. Family outbreaks of invasive community-associated methicillin-resistant Staphylococcus aureus infection. Clin Infect Dis 2006;42:e76-8.