Reactive oxygen species measure for rapid detection of infection in fluids

Analyzing material changes consistent with degradation of explanted polymeric hernia mesh related to clinical characteristics

BACKGROUND

Proposed mechanisms that potentially contribute to polypropylene mesh degradation after in vivo exposure include oxidizing species and mechanical strains induced by normal healing, tissue integration, muscle contraction, and the immediate and chronic inflammatory responses.

METHODS

This study explores these potential degradation mechanisms using 63 mesh implants retrieved from patients after a median implantation time of 24 months following hernia repair surgery (mesh explants) and analysis of multivariate associations between the material changes and clinical characteristics. Specifically, polypropylene mesh degradation was characterized in terms of material changes in surface oxidation, crystallinity and mechanical properties, and clinical characteristics included mesh placement location, medical history and mesh selection.

RESULTS

Compared to pristine control samples, subsets of mesh explants had evidence of surface oxidation, altered crystallinity, or changed mechanical properties. Using multivariate statistical approach to control for clinical characteristics, infection was a significant factor affecting changes in mesh stiffness and mesh class was a significant factor affecting polypropylene crystallinity changes.

CONCLUSIONS

Highly variable in vivo conditions expose mesh to mechanisms that alter clinical outcomes and potentially contribute to mesh degradation. These PP mesh explants after 0.5 to 13 years in vivo had measurable changes in surface chemistry, crystallinity and mechanical properties, with significant trends associated with factors of mesh placement, mesh class, and infection.

Pulmonary infections in critical/intensive care - rapid diagnosis and optimizing antimicrobial usage

PURPOSE OF REVIEW

Diagnosis of pulmonary infection, including hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) in the critically ill patient remains a common and therapeutically challenging diagnosis with significant attributable morbidity, mortality, and cost. Current clinical approaches to surveillance, early detection and, conventional culture-based microbiology are inadequate for optimal targeted antibiotic treatment and stewardship. Efforts to enhance diagnosis of HAP and VAP and the impact of these novel approaches on rational antimicrobial selection and stewardship are the focus of recent studies reviewed here.

RECENT FINDINGS

Recent consensus guidelines for diagnosis and management of HAP and VAP are relatively silent on the potential role of novel rapid microbiological techniques and reply heavily on conventional culture strategies of noninvasively obtained (including endotracheal aspirate samples). Novel rapid microbiological diagnostics, including nucleic acid amplification, mass spectrometry, and fluorescence microscopy-based technologies are promising approaches for the future. Exhaled breath biomarkers, including measurement of VOC represent a future approach.

SUMMARY

Further validation of novel diagnostic technology platforms will be required to evaluate their utility for enhancing diagnosis and guiding treatment of pulmonary infections in the critically ill. However, the integration of novel diagnostics for rapid microbial identification, resistance phenotyping, and antibiotic sensitivity testing into usual care practice could significantly transform the care of patients and potentially inform improved targeted antimicrobial selection, de-escalation, and stewardship.