I have a patient who had a failed mesh placement and a panniculectomy and who has developed at least three separate fistulas with a very large amount of output (3-4 L/24 hrs). Any suggestions? I am using an Eakin wound management pouch hooked up to wall suction.
Bacterial Swabs and the Chronic Wound: When, How, and What Do They Mean
- Wed, 9/3/08 - 10:25am
- 0 Comments
- 14651 reads
T he ability to diagnose infection in chronic wounds should be a well-honed clinical skill grounded in knowledge of human physiology, immunology, and microbiology. Instead, it has become a topic mired in controversy. Although it has been suggested that much of this controversy arises from lack of evidence, more than 5,000 "wound infection" articles were published in peer-reviewed journals over the past 12 years. Confusion may be based not so much on lack of evidence but rather on lack of balanced interpretation of evidence.
Poor clinical performance in diagnosing chronic wound infection may partly account for the fact that soft tissue infection is the leading indication for outpatient parenteral antibiotic therapy and the third most common indication for oral antibiotic use.1,2 An exhaustive study of chronic wound prevalence in Sweden has revealed that 60% of patients either were actively receiving antibiotics or had been treated with antibiotics in the previous 6 months.3 Another example of clinical perplexity is the current North American clinical practice guideline on management of pressure ulcers.4 Although this guideline recommends obtaining quantitative bacterial cultures rather than swab cultures, quantitative culture techniques are rarely utilized in the management of most chronic wounds.5
Culture methodology in particular has been prone to controversy. The technique of using a swab for microbiological sampling now has been practiced for more than 100 years. However, the swab remains much maligned, with critics questioning many aspects of this technique: What type of swab should be used? Should the swab be dry or premoistened? Does superficial swabbing of the wound bed reflect deeper tissue cultures? Does the swab miss fastidious organisms? How should the swab be rolled across the wound surface? Is it important to quantitate bacterial growth in chronic wounds?
When Should a Chronic Wound Be Cultured?
Determining when is far more important than determining how to culture a wound. As in much of medical practice, the timing of clinical action is sometimes more important than the action itself.
A wound should be cultured after wound infection has been clinically diagnosed. Clinical diagnosis of infection is essential before culturing because 100% of wounds are contaminated at the time of wounding (inoculated with organisms which subsequently do not actively divide).6 Soon after the inoculation event, 100% of wounds become colonized (where some micro-organisms replicate within a wound but do not harm the host).
Wound infection by definition implies that replicating micro-organisms within a wound are having a detrimental effect on the host. In a healthy host, the local signs of wound infection are seldom subtle and include swelling, induration, erythema, increased temperature, pain, increased exudate, foul odor, and eventual progressive wound breakdown. If allowed to progress, local infection becomes systemic. Systemic signs of sepsis include fever, rigors, chills, hypotension, multi-organ failure, and death. Unfortunately, these florid complications of chronic wound infection culminating in septicemic death continue to occur.7
Infection in chronic wounds may be quite subtle.8 Covert infections often are described as being out of bacterial balance when the pathogens in question have overcome the host immune response. Such wound infections are characterized by progressive wound breakdown or by a wound that appears to stall after previously showing signs of healing progress. In such wounds, ruling out other causes for wound failure (eg, lack of compliance with pressure downloading, inadequate perfusion, or inappropriate wound care) is important. Specific clinical attributes of these wounds include atrophy of previously exuberant granulation tissue, often with discoloration of the granulation tissue to a pale grey or deep red hue, with increased friability and bleeding.
References:
1. Nathwani D, Moitra S, Dunbar J, Crosby G, Peterkin G, Davey P. Skin and soft tissue infections: development of a collaborative management plan between community and hospital care. Int J Clin Pract. 1998;52(7):456-60.
2. MacDonald T, Collins D, McGilchrist M, Stevens J, McKendrick A, McDevitt D, Davey P. The utilisation and economic evaluation of antibiotics in primary care. J Antimicrob Chemother. 1995;35(1):191-204.
3. Tammelin A, Lindholm C, Hambraeus A. Chronic ulcers and antibiotic treatment. J Wound Care. 1998;7(9):435:7.
4. Bergstrom N, Allman R, Alvarez O, Bennet M, Carlson C, Frantz R, et al. Clinical Practice Guideline Number 15: Treatment of Pressure Ulcers. Rockville, Md: US Department of Health Human Services. Public Health Service. Agency for Health Care Policy and Research; 1994. AHCPR Publication 95-0652.
5. Thompson P, Smith D. What is infection? Am J Surg. 1994;167(suppl 1A):75-115.
6. Bowler P, Duerden B, Armstrong D. Wound microbiology and associated approaches to wound management. Clin Microbiol Rev. 2001;14(2):244-269.
7. DeVivo M, Kartus P, Stover S, Rutt R, Fine P. Cause of death for patients with spinal cord injuries. Arch Intern Med. 1989;149:1761-1766.
8. Dow G. Infection in chronic wounds. In: Krasner D, Rodeheaver G, Sibbald G (eds). Chronic Wound Care: A Clinical Source Book for Healthcare Professionals, Third Edition. Wayne, Pa.: HMP Communications; 2001:343-356.
9. Robson M, Heggers J. Bacterial quantification of open wounds. Mil Med. 1969;134:19-24.
10. Robson M. Wound infection: A failure of wound healing caused by an imbalance of bacteria. Surg Clin N Am. 1997;77(3):637-650.
11. Kucan J, Robson M, Heggers J, Ko F. Comparison of silver sulfadiazine, povidone-iodine, and physiologic saline in the treatment of chronic pressure ulcers.
J. Amer Geriatr Soc. 1981;29:232-235.
12. Robson M, Lea C, Dalton J, Heggers J. Quantitative bacteriology and delayed wound closure. Surg Forum. 1968;19:501-502.
13. Robson M, Heggers J. Delayed wound closures based on bacterial counts. J Surg Oncol. 1970;2:379-383.
14. Krizek T, Robson M, Kho E. Bacterial growth and skin graft survival. Surg Forum. 1967;18:518-519.
15. Bendy R, Nuccio P, Wolfe E, Collins B, Tamburro C, Glass W, Martin C. Relationship of quantitative wound bacterial counts to healing of decubiti. Effect of topical gentamicin. Antimicrob Agents Chemother. 1964;4:147-155.
16. Lyman I, Tenery J, Basson R. Correlation between decrease in bacterial load and rate of wound healing. Surg Gynecol Obstet. 1970;130(4) 616-621.
17. Robson M, Duke W, Krizek T. Rapid bacterial screening in the treatment of civilian wounds. J Surg Res. 1973;14:420-430.
18. Wright A, Fleming A, Colebrook L. The conditions under which the sterilization of wounds by physiologic agency can be obtained. Lancet. 1918;1:831-838.
19. Tenorio A, Jindrak K, Weiner M, et al: Accelerated healing in infected wounds. Surg Gynecol Obstet. 1976;142(4):537-543.
20. Woolfrey B, Fox J, Quall C. An evaluation of burn wound quantitative microbiology. Am Soc Clin Pathol. 1981;75(4):532-537.
21. Selkon J. Polybacterial infection - the role of anaerobic bacteria. Presented at the 6th European Pressure Ulcer Advisory Panel Open Meeting Budapest, Hungary, September 18-21, 2002.
22. Mayrand D, McBride B. Ecological relationships of bacteria involved in a simple, mixed anaerobic infection. Infect Immun. 1980;27:44-50.
23. Wheat L, Allen S, Henry M, Kernek C, Siders J, Kuebler T, Fineberg N, Norton J. Diabetic foot infections: bacteriologic analysis. Arch Intern Med. 1986;146:1935-1940.
24. Sapico F, Ginunas V, Thornhill-Joynes M, Canawati H, Capen D, Klein N, Khawam S, Montgomerie J. Quantitative microbiology of pressure sores in different stages of healing. Diagn Microbiol Infect Dis. 1986;5:31-38.
25. Ehrenkvanz N, Alfonso B, Nerenberg D. Irrigation-aspiration for culturing draining decubitus ulcers: correlation of bacteriologic findings with a clinical inflammatory scoring index. J Clin Microbiol. 1990;28(11):2389-2393.
26. Perry C, Pearson R, Miller G. Accuracy of cultures of material from swabbing of the superficial aspect of the wound and needle biopsy in the preoperative assessment of osteomyelitis. J Bone Joint Surg. 1991;73A:745-749.
27. Gilchrist B. Taking a wound swab. Nurs Times. 2000;96(supp 4):2.
28. Cooper R, Lawrence J. The isolation and identification of bacteria from wounds. J Wound Care. 1996;5(7):335-40.
29. Sapico F, Witte J, Canawati H, Montgomerie J, Bessman A. The infected foot of the diabetic patient: quantitative microbiology and analysis of clinical features. Rev Infect Dis. 1984;6(supp 1):S171-S176.
Post new comment