Outcome of debridement and retention in prosthetic joint infections by methicillin-resistant staphylococci, with special reference to rifampin and fusidic acid combination therapy.

The management of prosthetic joint infections remains a clinical challenge, particularly infections due to methicillin-resistant staphylococci. Previously, this infection was considered a contraindication to debridement and retention strategies. This retrospective cohort study examined the treatment and outcomes of patients with arthroplasty infection by methicillin-resistant staphylococci managed by debridement and retention in conjunction with rifampin-fusidic acid combination therapy. Over an 11-year period, there were 43 patients with infection by methicillin-resistant staphylococci managed with debridement and retention. This consisted of close-interval repeated arthrotomies with pulsatile lavage. Rifampin was combined with fusidic acid for the majority of patients (88%). Patients were monitored for a median of 33.5 months (interquartile range, 20 to 54 months). Overall, 9 patients experienced treatment failure, with 12- and 24-month estimates of infection-free survival of 86% (95% confidence interval [CI], 71 to 93%) and 77% (95% CI, 60 to 87%), respectively. The following factors were associated with treatment failure: methicillin-resistant Staphylococcus aureus (MRSA) arthroplasty infection, a single surgical debridement or ≥4 debridements, and the receipt of less than 90 days of antibiotic therapy. Patients with infection by methicillin-resistant coagulase-negative staphylococci (MR-CNS) were less likely to fail treatment. The overall treatment success rate reported in this study is comparable to those of other treatment modalities for prosthetic joint infections by methicillin-resistant staphylococci. Therefore, the debridement and retention of the prosthesis and rifampin-based antibiotic therapy are a valid treatment option for carefully selected patients.

Risk factors for prosthetic hip and knee infections according to arthroplasty site.

Prosthetic joint infection is a devastating complication of arthroplasty. Previous epidemiological studies have assessed factors associated with arthroplasty infections but have not assessed the impact of comorbidity on infection at different arthroplasty locations. We used a case-control design to investigate risk factors for prosthetic joint infection with reference to the anatomical site. During an eight-year period at a single hospital, 63 patients developed a prosthetic joint infection (36 hips, 27 knees). Cases of prosthetic hip or knee joint infection were matched 1:2 to controls. The results suggest that factors associated with arthroplasty infections differ with anatomical location. Following knee arthroplasty, wound discharge was associated with an increased risk of prosthetic joint infection whereas the presence of a drain tube reduced the risk. By contrast, increased body mass index, increased drain tube loss and superficial incisional surgical site infections (SSIs) were associated with prosthetic hip infection. When analysed as a combined cohort, systemic steroid use, increased SSI drain tube losses, wound discharge, and superficial incisional SSIs were predictors of infection.

Gram-negative prosthetic joint infection treated with debridement, prosthesis retention and antibiotic regimens including a fluoroquinolone.

Information is required about treatment outcomes of Gram-negative prosthetic joint infections treated with prosthesis retention and surgical debridement, especially where biofilm-active antibiotics such as fluoroquinolones are used. The outcome of 17 consecutive patients with an early Gram-negative prosthetic joint infection who had been treated with prosthesis retention and surgical debridement was analysed. Enterobacteriaceae were isolated in 16 patients and infections were mixed with other organisms in 13 (76%) patients. The median joint age was 17 days and the median duration of symptoms before debridement was 7 days. All patients initially received intravenous ß-lactam antibiotic therapy and 14 patients were then treated with oral ciprofloxacin. Treatment failure occurred in two patients over a median period of follow-up of 28 months. In only one patient was a relapsed Gram-negative infection responsible for the failure and this patient had not been treated with ciprofloxacin. The 2-year survival rate free of treatment failure was 94% (95% CI, 63-99%). Prosthesis retention with surgical debridement, in combination with antibiotic regimens including ciprofloxacin, was effective and should be considered for patients with early Gram-negative prosthetic joint infection.

Erysipelas-like inflammation following breast surgery.

Impaired lymph drainage is an inevitable consequence of any form of surgery that disrupts lymphatics, resulting in a degree of lymphoedema that may vary from subtle to dramatic and although classically involving an entire limb, may be more localised, confined to only a small area such as a skin flap. Infection is a well-recognised complication of lymphoedema. However, not all inflammatory episodes occurring in the setting of lymphatic dysfunction can be clearly attributed to infection as this article demonstrates. Five patients presented over a 5-year period with distinctive erysipelas-like inflammation affecting the breast which occurred several weeks following reduction mammaplasty in four patients and breast reconstruction in one patient. No clinical response was obtained with standard antibiotics. This inflammatory problem may represent a previously unreported complication of breast surgery with an incidence of 4% following reduction mammaplasty. Recent research supports the notion that this type of episode is most likely to be due to a non-infective inflammatory process related to lymphatic dysfunction induced by surgery.

Treatment of staphylococcal prosthetic joint infections with debridement, prosthesis retention and oral rifampicin and fusidic acid.

There is growing evidence of the efficacy of treating early staphylococcal infections of prosthetic joints with surgical debridement and prosthesis retention, combined with oral antibiotic regimens that include rifampicin in combination with a fluoroquinolone. With rising rates of fluoroquinolone-resistant staphylococci, evidence concerning the efficacy of alternative combinations of antibiotics is required. Twenty patients with staphylococcal prosthetic joint infections who had been treated with surgical debridement and prosthesis retention, and a combination of rifampicin and fusidic acid were analysed. The mean duration of symptoms before initial debridement was 16 (range 2-75) days. The median time of follow-up was 32 (range 6-76) months. Treatment failure occurred in two patients. The cumulative risk of treatment failure after 1 year was 11.76% (95% CI 3.08-39.40%). Two patients had their treatment changed because of nausea. Ten of 11 patients with infections involving methicillin-resistant Staphylococcus aureus had successful outcomes. Debridement without prosthesis removal, in combination with rifampicin and fusidic acid treatment, was effective and should be considered for patients with early staphylococcal prosthetic joint infections, including those with infections involving fluoroquinolone-resistant organisms.

Disseminated tuberculosis: still a diagnostic challenge.

Disseminated tuberculosis is notoriously difficult to diagnose and, with the decrease in tuberculosis incidence in Australia, familiarity with its manifestations has dwindled. We describe four bacteriologically proven cases which illustrate the range of presentations and diagnostic difficulties. Surprisingly, immunosuppressive therapy need not cause rapid deterioration. Disseminated tuberculosis should be considered in any patient with multisystem illness who is at risk of tuberculosis, particularly if born overseas. In the absence of confirmatory results, a prompt therapeutic trial may be life-saving.

The effect of field of view size on steady-state pupil diameter.

Studies of the relationship between luminance and pupil diameter have produced widely differing results. This research note explores the possibility that this is due, in part, to differences in the size of the adapting fields used by various workers. We present measurements of pupil diameter as a function of luminance for a variety of field subtenses. The results indicate a consistent trend for smaller subtenses to produce less pupil constriction. For field diameters of up to 25 degrees, replotting the data in terms of corneal flux density (i.e. the product of luminance and subtended area) causes an approximate convergence onto a single function described by D = 7.75-5.75 [(F/846)0.41/((F/846)0.41 / 2)] where D is the pupil diameter (mm) and F is the corneal flux density (cdm-2 deg2). This equation should be of some practical use in estimation of natural pupil diameter.

A case of Vibrio vulnificus septicaemia acquired in Victoria.

The clinical features and laboratory findings of a case of Vibrio vulnificus septicaemia are reported. The illness occurred in a previously well 68-year-old man who was accidentally spiked in the buttock by the dorsal spine of a flathead caught in Tamboon Inlet, near Mallacoota, Victoria. The clinical picture of an acute septicaemic illness with shock, associated with metastatic cellulitic lesions on the lower limbs progressing to bulla formation, skin necrosis, necrotising fasciitis and myositis, is characteristic of V. vulnificus septicaemia. It would appear that tetracyclines are the drugs of choice. Surgical debridement may be necessary. Clinical recognition of this rare but characteristic illness will facilitate early effective chemotherapy. To our knowledge this is the southern-most case reported in Australia.

Atypical pneumonia: recognition and treatment.

While the term "atypical pneumonia" has been in use for many years, it cannot in fact be defined. However, there is a persuasive reason to retain the clinical use of the term, and that is to provide a guide for the clinician in the choice of empirical antibiotic therapy for patients with acute pneumonia. Atypical pneumonia, then, is a descriptive term for a common clinical syndrome. Provided certain clinicoepidemiological groups are excluded, the most common infectious causes of this syndrome are Mycoplasma pneumoniae, Chlamydia psittaci, Coxiella burneti, and Legionella species, but it should be stressed that the syndrome may occasionally be produced by other infectious and non-infectious diseases. Conversely, the atypical pneumonia syndrome occupies only one part of the clinical spectrum of disease that is caused by these organisms. This becomes important when one is selecting antibiotic therapy for patients with other respiratory syndromes, especially those with life-threatening disease. The antimicrobial therapy of the three common causes of atypical pneumonia is discussed in detail.

Respiratory syncytial virus pneumonitis in adults.

Two cases of respiratory syncytial virus pneumonitis in adults area described. In both patients, the clinical picture of the adult respiratory distress syndrome, with marked tachypnoea. hypoxaemia and bilateral diffuse pulmonary infiltrates, was present. One patient had systemic lupus erythematosus, while the other had chronic obstructive lung disease and was a heavy drinker of alcohol. Both patients survived and recovered after a prolonged stay in hospital.