RESUMO
Atmospheric pressure plasma jets are gaining a lot of attention due to their widespread applications in the field of bio-decontamination, polymer modification, material processing, deposition of thin film, and nanoparticle fabrication. Herein, we are reporting the disinfection of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria using plasma jet. In this regard, Ar-O2, Ar-N2, and Ar-O2-N2 mixture plasma is generated and characterized using optical and electrical characterization. Variation in plasma parameters like electron temperature, electron density, and reactive species production is monitored with discharge parameters such as applied voltage and feed gas concentration. Results show that the peak average power consumed in Ar-O2, Ar-N2, and Ar-O2-N2 mixture plasma is found to be 4.45, 2.93, and 4.35 W respectively, at 8 kV. Moreover, it is noted that by increasing applied voltage, the electron temperature, electron density, and reactive species production also increases. It is worth noting that electron temperature increases with increase in oxygen concentration in the mixture (, while it decreases with increase in nitrogen concentration in the mixture (Ar-N2). Similarly, a decreasing trend in electron temperature is noted for Ar-O2-N2 mixture plasma. On the other hand, a decreasing trend in electron density is noted for all the mixtures. Reduction in viable colonies of Pseudomonas aeruginosa, Staphylococcus Aureus, and Escherichia coli were confirmed by the serial dilution method. The inactivation efficiency of pulsed DC plasma generated, in the Ar-N2 mixture at 8 kV and 6 KHz, was evaluated against P. aeruginosa, S. aureus and E. coli bacteria by measuring the number of surviving cells versus plasma treatment time. Results showed that after 240 s of plasma treatment, the number of survival colonies of the mentioned bacteria was reduced to less than 30 CFU/mL.
RESUMO
OBJECTIVE: To evaluate the effect of vacuum-assisted closure (VAC) therapy on wound management by measuring the graft take, wound healing time, need for any re-grafting and duration of hospitalization. STUDY DESIGN: Single blinded randomized controlled trial. PLACE AND DURATION OF STUDY: This study was carried out in the Department of Plastic and Reconstructive Surgery, Pakistan Institute of Medical Sciences (PIMS), Islamabad, from October 2007 to December 2009. METHODOLOGY: A total of 100 adult patients of either gender with acute traumatic wounds were included. Patients who needed flap coverage as the primary intervention, and those with Diabetes, malignancy, bleeding diathesis were excluded. Half of the patients were randomly assigned to the intervention group and the rest to the control group with lottery method. All wounds were initially subjected to thorough excision. Wound bed preparation for STSG (split thickness skin graft) was achieved using 10 days pre-treatment with VAC dressings in the intervention group while employing normal saline gauzes in the control group. All patients were subsequently treated with STSG. The primary outcome measure was graft take while the secondary outcome measures included wound healing time, need for any re-grafting and duration of hospital stay. Results were compared in both groups using chi-square test. RESULTS: Marked differences were found in favour of the VAC therapy group with respect to the various wound management outcome measures studied. i.e. graft take (greater than 95% graft take in 90% of VAC therapy group vs. 18% of controls), wound healing time (2 weeks postgrafting in 90% of VAC therapy group vs. 18% of controls), need for regrafting (none among VAC therapy group vs. 8% of controls) and duration of hospital stay (less than 3 weeks in 90% of VAC therapy group vs. 18% of controls). CONCLUSION: VAC therapy should be employed in the pre-treatment of wounds planned to be reconstructed with STSG, since it has marked advantages in the wound bed preparation compared with the traditional normal saline gauze dressings.
