The clinical impact of hydro-responsive dressings in dynamic wound healing: Part II

OBJECTIVE

Over the course of a wound's healing trajectory, whether the wound is acute or hard-to-heal, management is likely to involve the use of several different dressing types. Minimising the complexity of treatment (in terms of dressing usage) would aid clinicians in providing effective wound care but excellent clinical outcomes must remain the primary goal.

METHOD

This study was an open-labelled, non-comparative study assessing the clinical effectiveness of a coordinated wound dressing treatment regimen. After an initial phase of using a hydro-responsive wound dressing (HydroClean, HRWD-1, PAUL HARTMANN AG, Germany) to cleanse and debride hard-to-heal wounds, the wounds were subsequently treated with either HydroTac (HRWD-2, PAUL HARTMANN AG, Germany) (to maintain healing progression and re-epithelialisation) or RespoSorb (a superabsorbent dressing, PAUL HARTMANN AG, Germany) (to manage moderate-to-high levels of exudate). The Pressure Ulcer Scale for Healing (PUSH) assessment tool was used to measure the wound status over the course of the treatment period and to assess several wound status parameters (for example, wound area, exudate levels and wound characteristics such as level of re-epithelialisation).

RESULTS

The results from this study demonstrated that wounds treated with HRWD-2 showed a positive healing response when using the PUSH score assessment tool with a significant mean reduction (p<0.0001) in the PUSH score of wounds treated with HRWD-2, with >75% of wounds being closed by the end of the study. This result underlines the effectiveness of HRWD-2 in supporting healing progression.

CONCLUSION

The results from this study support the coordinated use of HRWDs for the effective management and treatment of a variety of hard-to-heal wounds.

Coxiella burnetti prosthetic joint infection in an immunocompromised woman: iterative surgeries, prolonged ofloxacin-rifampin treatment and complex reconstruction were needed for the cure

Background

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii, a strictly intracellular pathogen that can cause acute and chronic infection. Chronic Q fever can occur in immunocompetent as well as in immuno-compromised hosts, as a persistent localized infection. The main localizations are endocardial, vascular and, less frequently, osteoarticular. The most frequent osteoarticular form is spondyliscitis. Recommended treatment is combined doxycycline and hydroxychloroquine for 18 months, with cotrimoxazole as another option. Coxiella burnetti infection has been implicated in rare cases of prosthetic joint infection (PJI), and the medical and surgical management and outcome in such cases have been little reported.

Case presentation

We report an unusual case of chronic Q fever involving a hip arthroplasty in an immunocompromised woman treated with tumor necrosis factor (TNF)-α blockers for rheumatoid arthritis. Numerous surgical procedures (explantation, “second look”, femoral resection and revision by megaprosthesis), modification of the immunosuppressant therapy and switch from doxycycline-hydroxychloroquine to prolonged ofloxacin-rifampin combination therapy were needed to achieve reconstruction and treat the PJI, with a follow-up of 7 years.

Conclusions

Coxiella burnetti PJI is a complex infection that requires dedicated management in an experienced reference center. Combined use of ofloxacin-rifampin can be effective.

Evaluation of intraosteoblastic activity of dalbavancin against Staphylococcus aureus in an ex vivo model of bone cell infection

OBJECTIVES

Long-acting lipoglycopeptides are promising therapeutic options in Staphylococcus aureus bone and joint infections (BJIs). This study evaluated the ability of dalbavancin to eradicate the intraosteoblastic reservoir of S. aureus, associated with BJI chronicity.

METHODS

Osteoblastic cells were infected with a standardized inoculum of the S. aureus reference strain HG001 and incubated for 24 h with dalbavancin, vancomycin or rifampicin using the MIC, 10×MIC, 100×MIC and/or the intraosseous concentrations reached using standard therapeutic doses (i.e. vancomycin, 10 mg/L; rifampicin, 2 mg/L; and dalbavancin, 6 mg/L). The remaining intracellular bacteria were quantified by plating cell lysates.

RESULTS

MICs of dalbavancin, vancomycin and rifampicin were 0.125, 1 and 0.004 mg/L, respectively. Dalbavancin significantly reduced the intracellular inoculum of S. aureus starting at a concentration equal to the MIC, with a significant dose effect, ranging from a reduction of 31.4% (95% CI = 17.6%-45.2%) at MIC to 51.6% (95% CI = 39.8%-63.4%) at 100×MIC compared with untreated cells. Of note, dalbavancin was the only molecule to significantly reduce the intraosteoblastic inoculum at low concentration (MIC). At intraosseous concentrations, dalbavancin reduced the intracellular inoculum by 49.6% (95% CI = 45.1%-54.1%) compared with untreated cells (P < 0.001), with no significant difference compared with vancomycin (38.1%; 95% CI = 19.2%-57.0%; P = 0.646), and was less efficient than rifampicin (69.0%; 95% CI = 63.2-74.8; P < 0.001).

CONCLUSIONS

Dalbavancin was able to decrease the intraosteoblastic S. aureus inoculum by 50% at intraosseous concentrations reached during standard human therapeutic dosing, with no difference compared with vancomycin, and remained less efficient than rifampicin. However, it was the only molecule significantly active at low concentration.

The clinical impact of hydroresponsive dressings in dynamic wound healing: Part I

OBJECTIVE

Management of any wound, either acute or hard-to-heal, might involve the use of multiple and different wound dressings in its treatment. This approach is necessary to overcome the myriad of clinical challenges the wound presents, as well as any underlying comorbidities that might affect the clinical outcomes. This article describes the clinical effectiveness of a coordinated wound dressing treatment regimen.

METHOD

This was an open-labelled non-comparative study involving patients with a variety of hard-to-heal and acute wounds of differing levels of severity, but all of which required removal of devitalised tissue to enable wound healing to progress. The first phase used the hydroresponsive wound dressing HydroClean (PAUL HARTMANN AG, Germany). The PUSH score was used as the primary measurement parameter.

RESULTS

A total of 86 patients (38 male/48 female), with a mean age of 67.7±21.7 years, took part in the study. The results showed that the hydroresponsive dressing was effective in managing wound exudate production and promoting wound cleansing and debridement, supporting good wound bed preparation. Wound closure was observed in 16/86 (18.6%) wounds at the end of the study (20 weeks). This enabled clinicians to switch to alternative wound dressings to promote subsequent clinical healing outcomes.

CONCLUSION

In this study, the hydroresponsive wound dressing was highly effective in preparing a clean wound bed such that the next stage of wound healing could be supported.

Bone and Joint Infection Involving Corynebacterium spp.: From Clinical Features to Pathophysiological Pathways

Introduction: Corynebacteria represent often-neglected etiological agents of post-traumatic and/or post-operative bone and joint infection (BJI). We describe here clinical characteristics and bacteriological determinants of this condition. Methods: A retrospective cohort study described characteristics, outcome and determinants of treatment failure of all patients with proven Corynebacterium spp. BJI (i.e., ≥2 culture-positive gold-standard samples). Available strains were further characterized regarding their antibiotic susceptibilies, abilities to form early (BioFilm Ring Test®) and mature (crystal violet staining method) biofilms and to invade osteoblasts (gentamicin protection assay). Results: The 51 included BJI were mostly chronic (88.2%), orthopedic device-related (74.5%) and polymicrobial (78.4%). After a follow-up of 60.7 weeks (IQR, 30.1-115.1), 20 (39.2%) treatment failures were observed, including 4 Corynebacterium-documented relapses, mostly associated with non-optimal surgical management (OR 7.291; p = 0.039). Internalization rate within MG63 human osteoblasts was higher for strains isolated from delayed (>3 months) BJI (p < 0.001). Infection of murine osteoblasts deleted for the β1-integrin resulted in a drastic reduction in the internalization rate. No difference was observed regarding biofilm formation. Conclusions: Surgical management plays a crucial role in outcome of BJI involving corynebacteria, as often chronic and device-associated infections. Sanctuarisation within osteoblasts, implicating the β1 cellular integrin, may represent a pivotal virulence factor associated with BJI chronicity.

18F-fluorodeoxyglucose positron emission tomography is useful for the diagnosis of intraocular sarcoidosis in patients with a normal CT scan

AIM

To assess the usefulness of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET/CT) and the predictive factors for the diagnosis of sarcoidosis in patients with uveitis who have normal thoracic tomography.

METHODS

We retrospectively reviewed 67 consecutive patients with uveitis of unknown aetiology or a suspected sarcoidosis. All patients with normal thoracic tomography underwent an ¹⁸F-FDG PET/CT, which was blindly reinterpreted. We then assessed the proportion of positive ¹⁸F-FDG PET/CT and the impact on the final aetiology, using Abad's criteria for the diagnosis of intraocular sarcoidosis.

RESULTS

19 of the 67 patients (28.4%) had mediastinal hypermetabolic foci on their ¹⁸F-FDG PET/CT consistent with sarcoidosis. It identified a biopsy site in two cases, which were consistent with sarcoidosis. At the end of the study, six patients (10%) had a proven sarcoidosis, six patients (9%) were considered as having a presumed sarcoidosis and 18 patients (26.9%) as having indeterminate sarcoidosis. ¹⁸F-FDG PET/CT enabled the diagnosis of presumed sarcoidosis in these six patients. An older age at diagnosis (p=0.004) and the presence of synechiae (p=0.02) were significantly related to an abnormal ¹⁸F-FDG PET/CT, with a trend for an elevated ACE (p=0.0993). We established a nomogram to estimate the probability of having positive findings on the ¹⁸F-FDG PET/CT according to different predictive factors.

CONCLUSION

¹⁸F-FDG PET/CT enabled the diagnosis of intraocular sarcoidosis even in patients with a normal CT scan. Older age at diagnosis, presence of synechiae and elevated ACE are associated with positive findings on ¹⁸F-FDG PET/CT consistent with sarcoidosis.

Corynebacterium Bone and Joint Infection (BJI): A Retrospective Cohort Study in a Reference Center for BJI Management

Background

Corynebacterium is a rare etiologic agent of BJI. We aimed to describe this rare clinical condition and to assess treatment failure determinants.

Methods

All adult patients with proven Corynebacterium BJI (i.e., consistent clinical/radiological signs, AND ≥2 reliable positive bacteriological samples, AND treated as such) were included in a retrospective cohort study. After cohort description, determinants of treatment failure (i.e., infection persistence, relapse, requirement of additional surgical procedure, and BJI-related death) were determined using stepwise logistic regression and Kaplan-–Meier curve analysis.

Results

The 51 included BJI were more frequently chronic (88.2%), orthopaedic device related (ODI, 74.5%) and polymicrobial (78.4%). Surgery was performed in 92.2% of cases, and considered as appropriate in 76.5% of them. The main first-line antimicrobials were glycopeptides (68.6%), β-lactams (50%), and/or clindamycin (10.0%). Three (5.9%) patients received daptomycin as part of first-line regimen, and 8 (15.7%) at any point of treatment. After a follow-up of 60.7 (IQR 30.1–115.1) weeks, 20 (39.2%) treatment failures were observed, including 4 (20%) Corynebacterium-documented relapse. Independent risk factors were initial biological inflammatory syndrome (OR 16.1; P = 0,030) and inappropriate surgical management (OR 7.481; P = 0.036). Interestingly, all patients receiving daptomycin as part of first-line regimen failed (P < 0.001), including one patient with a Corynebacterium-documented relapse with a daptomycin increased MIC. Among patients with ODI, survival curve analysis disclosed a worst prognosis in case of prosthetic joint infection (P = 0.030), unappropriate surgical management (P = 0.029) and daptomycin use as first-line regimen (P < 0.001).

Conclusion

Corynebacterium BJI is a poorly known condition, frequently chronic, and polymicrobial. An important rate of failure was observed, associated with inappropriate surgical management and daptomycin use as part of first-line regimen. As described for other clinical conditions such as infective endocarditis, daptomycin should be avoid or used in combination therapy to prevent resistance selection and treatment failure.

Disclosures

T. Ferry, HERAEUS: Consultant, Speaker honorarium. S. Lustig, Heraeus: Consultant, Consulting fee