Rapid Responses to:
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Rapid Responses: Rapid Responses published:
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Incidence and timing
- Eamonn J Clarke (11 June 2009)
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Alarmed
- Adrienne JJ Garner (11 June 2009)
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Bad bugs, No drugs ….. the drying pipeline of antibiotics
- Rashmi Sharma, Achyut Guleri, Blackpool Victoria Hospital (11 June 2009)
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Prosthetic Joint Infection - a team approach
- Elizabeth Darley, Gordon Bannister, Ashley Blom, Alasdair MacGowan, Kim Jacobson, James Murray. (27 June 2009)
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Nuclear medicine imaging in the infected prosthetic joint: misquoted and misunderstood.
- Patrick A. Fielding, Suresh Dalavaye and Liam McKnight (14 July 2009)
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Managing Prosthetic Joint Infection without long courses of systemic antibiotics
- Rob Townsend, David Harvey, Robert Kerry, Ian Stockley (21 July 2009)
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Eamonn J Clarke, GP PE14 9BT
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Some of the figures quoted may cause confusion. They certainly confused me.
In the fifth paragraph the authors state: "The proportion of prosthetic joints that become infected within three months of arthroplasty varies widely—from 29% to 69% in cohorts from the United Kingdom." This may seem at odds with the incidence of prosthetic joint infections quoted in the opening paragraph of "between 0.6% and 2% per joint per year." However reading the references reveals that of those prosthetic joints that become infected, between 29-69% of these infections occurs in the first three months after surgery. The fifth paragraph discusses when infections are likely to occur. I hope that is helpful. A humble GP. Competing interests: None declared |
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Adrienne JJ Garner, Locum GP HP4 2PN
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I have re-read the following sentence many times. You say: "The proportion of prosthetic joints that become infected within three months of arthroplasty varies widely - from 29% to 69% in cohorts from the United Kingdom" If this were true I doubt many people would opt for arthroplasty. I suspect what you mean is that: of the joints that become infected 29-69% do so in the first three months. Fortunately in the opening paragraph you do say that "subsequent prosthetic joint infection is uncommon". Am I right in my assumption or am I missing something? Otherwise I found the article very informative, thank you. Dr Adrienne Garner Competing interests: None declared |
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Rashmi Sharma, consultant microbiologist Royal Blackburn Hospital, Blackburn BB2 3HH, Achyut Guleri, Blackpool Victoria Hospital
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We must congratulate the authors for a much needed clear and comprehensive discussion of a rather complex subject, but would like to draw attention of the global readership of this journal to a few relevant points for consideration by district general hospital clinicians contemplating implementation of these recommendations: 1. The antibiotic resistance patterns vary between orthopaedic units
in specialist referral centres [such as Nuffield] and district general
hospitals.
The value of choosing empirical antibiotics based on local epidemiology cannot be emphasised enough. There is a real danger that the orthopaedic consultants may be tempted to ignore their local epidemiology i.e. antibiotic sensitivity/resistance profile of their resident flora and advice from their microbiology department, and use carbapenems empirically as well as for treatment of anaerobic infection where the use of narrow spectrum agents such as clindamycin or metronidazole may be more appropriate initially as intravenous treatment rather than only as oral option later1,2. Anaerobic infections’ are in fact unusual in primary prosthetic joint replacement, although metronidazole resistant proprioniibcaterium acnes are commoner in revision joints. Administration of carbapenems for the treatment of enterobacteriaceae where the isolate can be targeted by co-amoxyclav, piperacillin- tazobactam, fluoroquinolone or a 3rd generation cephalosporin cannot be justified. Emergence of carbapenem resistance in Pseudomonas, Acinetobacter and Klebsiella in the UK is a cause for concern3-5. Using carbapenems as first line antibiotics may compromise their use in situations that warrant their use. We are aware of little data justifying the use of carbapenems in the management of prosthetic joint infections, although they have a place where the bacterial resistance precludes the use of any other antibiotic. The use of oral doxycycline with rifampicin, when the decision to retain the implant has been made, raises more questions as doxycycline achieves poor concentration in bone6. The universal concern of "drying antibiotic pipeline and rising antibacterial resistance" as expressed by the IDSA president Dr. Dalovisio in the white paper titled ‘Bad bugs, No Drugs’ bring home the truth that we have very limited agents that are still effective against multi -drug resistant Gram negative bacteria, carbapenems being the mainstay7. If we were to lose these antibiotics following overuse, what options would we be left with when these multidrug resistant bacteria are identified as causing prosthetic joint infections? References 1. http://www.uptodate.com. Management of prosthetic joint infections 2.Zimmerli W, Trampuz A, Ochsner P E. Prosthetic joint infections. N Engl J Med 2004;351:1645-54. 3. Livermore D and Warner M. Clover leaves for carbapenemases. ARMRL newsletter (HPA) Summer 2008, Issue 21 4. Woodford N, Salso S, Tysall L, Coelho J, et al. Emergence of Pseudomonas spp. with VIM-type carbapenemases in the United Kingdom. Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. C2-2019 5. Guleri A, Trautt E, Lunt B and Palmer R. Rising carbapenem resistance in Pseudomonas and multidrug resistance in Enterobactericeae at a large district hospital in northwest England – How relevant is antimicrobial disc susceptibility testing?. Presented at the 19th European conference of clinical microbiology and infectious diseases, Helsinki, 15th-19th May, 2009 [unpublished] 6. Meyers B, Salvatore M. Tetracyclines and chloramphenicol. In: Mandell G, Bennett J and Dolin R. Principles and Practice of Infectious Diseases. Sixth Edition. Volume 1. London. Churchill Livingstone.356-366. 7.United States of America. Infectious Diseases Society of America. Bad Bugs No Drugs (2004) Competing interests: None declared |
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Elizabeth Darley, Medical Microbiologist Southmead Hospital, North Bristol NHS Trust, Bristol. BS10 5NB, Gordon Bannister, Ashley Blom, Alasdair MacGowan, Kim Jacobson, James Murray.
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Dear Sir We read with interest the recent review article by Matthews et al ‘Diagnosis and Management of prosthetic joint infection’ (1). We have particular interest in the orthopaedic and antimicrobial treatment of patients with prosthetic joint infections and agree that this is an area with little evidence base with regard to route and duration of antibiotic administration. Clinicians must decide on a treatment course for their patients that will optimise outcome both in the short term and throughout the lifespan of the prosthesis or limb, without subjecting patients to the associated adverse effects of unnecessarily long course of antibiotics, or requirements for protracted intravenous access. We would emphasise that liaison between orthopaedic surgeon and an infection specialist, usually a medical microbiologist, is not only advisable but essential for these patients, as is the expertise of the surgeon. We have recently reported the outcome data, of all patients treated in the Avon Orthopaedic centre over 2 years for infected prosthetic hip joint, managed with one or two stage revision (2). Almost all of these patients were operated by one of three surgeons who have expertise in performing the appropriate radical excision of infected tissue. Nineteen patients treated with 2-stage revision for infection had no symptoms of relapse at 2-3 years follow up. In all cases the organisms treated were susceptible to oral antibiotic combinations, most often ciprofloxacin and rifampicin or alternatively, rifampicin with clindamycin or with minocycline depending on antibiograms for Gram-positive organisms and ciprofloxacin monotherapy for Gram- negative organisms. Seventeen patients were able to absorb and switch from iv to oral antibiotics early in treatment and none required any home intravenous antibiotic therapy. Numbers of patients managed with one stage revision were much smaller (n=6), but no cases of relapse were found in this group either. We accept this is a relatively small number of patients, however it has endorsed for us the efficacy of our treatment approach of aiming for approximately 2 initial weeks iv therapy before switching to longer duration of oral antibiotics. Three years ago we introduced a combined clinic for all patients with prosthetic bone and joint infection; referred patients are reviewed in these monthly clinics by 2 orthopaedic consultants with considerable experience in infected revision surgery and a consultant medical microbiologist with interest in chemotherapy of orthopaedic infection. Our initial outcome data supports this approach and we have found early switch to oral antibiotics both as effective as reported outcomes for regimens with longer duration of iv antibiotics and more cost effective in drug costs and lack of need to resource a home iv therapy team. With the current and extrapolated growth in joint arthroplasty, prosthetic joint infection will continue to rise. In agreement with authors, there is certainly a need for further research, both with respect to the duration of intravenous antibiotics and minimum overall duration of antibiotic therapy. We believe the combined clinical team approach to this problem is vital for both patient care and future research into this challenging field. 1.Matthew P, Berendt A, McNally A, Byren I. Diagnosis and management of prosthetic joint infection BMJ 2009; 338:1378-1383 2. Early intravenous to oral antibiotic switch therapy is effective in the treatment of infected total hip replacement. Darley E, Bannister G, Blom A, MacGowan A, Jacobson S , Alfouzan, W. 19th European Congress of Clinical Microbiology and Infectious Diseases.16 - 19 May 2009. Helsinki Competing interests: None declared |
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Patrick A. Fielding, Consultant Radiologist Morriston Hospital,ABM trust, Swansea SA6 6NL, Suresh Dalavaye and Liam McKnight
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Dear Sir, We read with interest the recent article by Matthews et. al. on June 6, 2009. In particular we were interested in the authors opinions as regards imaging in the potentially failed joint prosthesis.1 In our centre, we routinely use radionuclide investigations in this clinical situation. Indeed combined leucocyte/colloid scintigraphy is used in many centres throughout the UK and internationally. We therefore find the very brief mention of nuclear medicine techniques and the conclusion that none were of value a little surprising. The authors cite a paper regarding the conservative management of the infected joint prosthesis.2 Although positive leucocyte scintigraphy was used as an acceptance criteria for this study, the study was not focused on evaluating the accuracy of leucocyte scintigraphy but rather the outcomes of pursuing a conservative management in the infected prosthetic joint. Indeed this paper makes no attempt to evaluate the sensitivity or specificity of labelled leucocyte imaging in periprosthetic infection. We find this a surprising choice of paper to cite amongst the many articles which do address the diagnostic performance of leucocyte scintigraphy in this situation. The authors go on to cite a review article 3 in which imaging studies in peri prosthetic infections are discussed. In this previous review article the authors state “although bone scintigraphy with technetium 99m labelled methylene diphosphonate has a very high sensitivity, it lacks specificity for infection.” this review is therefore making a comment on isotope bone scanning with MDP rather than imaging with radiolabelled leucocytes which was the imaging test used in the previously cited paper. The previous review3 makes no suggestion that leucocyte scintigraphy has limited specificity as the authors suggest. Unfortunately it appears that Dr Matthews and her colleagues are confused as regards the difference between bone scintigraphy with MDP and radiolabelled leucocyte scintigraphy and perhaps it is appropriate to clarify this potential misunderstanding. An excellent review on this subject has been recently published.4 Skeletal scintigraphy with MDP is widely available and easily performed. The delayed phase images give information about bone turnover. This is sensitive for detecting a failing joint prosthesis but non-specific as to its cause. Most patients with a painful joint prosthesis will have a positive isotope bone scan and therefore we agree that the diagnostic value of this in cases of possible infection is very limited. The nuclear medicine investigation of choice in suspected periprosthetic infection is combined leucocyte/marrow imaging.4 Labelled leucocytes are taken up into sites of bony infection, but also into reticuloendothelial cells which may redistribute physiologically around an implanted prostheses. Technetium labelled colloid is taken up into cells of reticuloendothelial origin but not into infected bone. ”Subtracting” the colloid appearances from the leucocyte appearances leaves only areas in which there is active bony infection. The literature has fairly consistently shown a high sensitivity, specificity and accuracy of this technique for the diagnosis of prosthetic infection. A recent study, examining 150 failed prostheses in which there were histopathologically and microbiologically confirmed outcomes yielded sensitivity, specificity and accuracy of 96%, 87% and 91% respectively5. The clinical scenario of the potentially infected joint prosthesis is indeed a problematic one and diagnosis is both vitally important and also fraught with difficulty. Combined leucocyte/colloid scintigraphy is however sensitive, specific and accurate in this situation. Certainly in our centre this retains an important part in the multi-modality and multidisciplinary assessment of periprosthetic joint infection. References 1. Matthews PC, Berendt AR, McNally MA, Byren I Diagnosis and management of prosthetic joint infection. BMJ. 2009 338 1378-1383 2. Pavoni, GL, Giannella, M, Falcoone, M et al Conservative medical therapy of prosthetic joint infections: retrospective analysis of an 8 year experience Clin Microbiol Infect 2004;10:831-7 3. Zimmerli, W, Trampuz A, Ochner PE. Prosthetic–joint infections N Engl J Med 2004;351:1645-54 4. Love C, Marwin SE, Palestro CJ. Nuclear medicine and the infected joint replacement Semin Nucl Med 2009 39: 66-78 5. Love C, Tronco GG, Yu AK et al Diagnosing lower extremity prosthetic joint infection: bone, gallium and labelled leucocyte imaging. Presented at the 2008 SNM meeting, New Orleans LA, June 14- 18, 2008. Competing interests: None declared |
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Rob Townsend, Consultant Medical Microbiologist Northern General Hospital S5 7AU, David Harvey, Robert Kerry, Ian Stockley
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Dear Sir, In reply to the recent BMJ article on the diagnosis and management of prosthetic joint infection by Matthews et al. (BMJ 2009;338:b1773) we would like to highlight an equally successful method for the management of these infections which does not require systemic antibiotics or prolonged hospital admission (or IV antibiotics via outpatient IV services). Our approach in Sheffield is to target antibiotic therapy to a known organism isolated from either a diagnostic aspirate or joint washout (in the case of early PJI). At the first stage revision following thorough debridement of all infected material and after obtaining the 5 microbiology tissue samples we then use antibiotic loaded cement beads containing an appropriate antibiotic based upon previously obtained aspirate results (1,2). Beyond the surgical prophylaxis systemic antibiotics are generally not required as high levels of eluted antibiotic from the cement beads provide effective local antimicrobial activity with minimal/no systemic absorption. In common with other methods the second stage is the same, re -implantation in to a now sterile site with more microbiology samples prior to the prophylactic antibiotics. The long-term outcome data using this approach is comparable to the approach described in the article (3). The authors state that the management of PJI using antibiotic loaded spacers is expensive, time consuming and results in tissue damage, however we believe that infected prosthetic material requires surgical debridement along with dead tissue/bone and that thorough surgery does indeed take time. In terms of cost we believe that a patient being successfully treated at home with antibiotic loaded cement in situ is more cost effective than a patient receiving IV antibiotics in an inpatient bed or an outpatient IV service. We feel the potential benefits offered by this approach are: • Reduced C. difficile infection (less systemic antibiotic exposure). • Reduced line associated bacteraemias including MRSA (as no lines required). • Reduced side-effects from long duration antibiotics (eg neutropenia, nephrotoxicity etc). • Reduced inpatient stay leading to reduced costs and improved patient satisfaction. The management of the infected prosthetic joint is essentially surgical but with good supportive microbiology and we believe that in our unit at least this approach is successful and in many ways preferable to long courses of antibiotics and especially the broad spectrum IV agents. References 1. Williams JL, Norman P, Stockley I. The value of hip aspiration versus tissue biopsy in diagnosing infection before exchange hip arthroplasty surgery. J Arthroplasty 2004;19:582-6. 2. Ali F, Wilkinson JM, Cooper JR et al. Accuracy of joint aspiration for the preoperative diagnosis of infection in total hip arthroplasty. J Arthroplasty 2006;21:221-6. 3. Stockley I, Mockford BJ, Hoad-Reddick A, Norman P. The use of two- stage exchange arthroplasty with depot antibiotics in the absence of long- term antibiotic therapy in infected total hip replacement. J Bone Joint Surg Br. 2008 Feb;90(2):145-8 Competing interests: None declared |
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