Terapia fotodinâmica antimicrobiana na cavidade oral de pacientes internados em centro de terapia intensiva

Abstract

Photodynamic Therapy is the interaction of a photosensitizer with a light source of a specific wavelength. With photochemical interaction, cellular destruction of microorganisms occurs by oxidative stress. Intensive care patients have a high chance of developing changes that are often related to pathogens present in the oral microbiota. The objective of this research is to evaluate the effect of photodynamic therapy on oral microorganisms in patients admitted to an intensive care unit. Three fluid collections were carried out orally in the research: the first performed in the first 24 hours of hospitalization of the patient. Two samples, before and after intervention, were 48 hours after the first collection. In the participants allocated to the experimental group, Photodynamic Therapy was applied in a single session in the oral cavity in the region of the retromolar triangle. In the participants allocated to the control group, methylene blue was applied to the retromolar triangle without laser irradiation. Those samples at the hospital were sent to the microbiology laboratory for counting Colony Forming Units (CFU) and identification of microorganisms. This research was approved by the Research Ethics Committee of the Federal University of Amapá - UNIFAP under No. 2,349,365 and registered in the Brazilian Registry of Clinical Trials - ReBEC: 6VZH6P. There was a numerical increase in microorganisms in the oral microbiota of patients after 48 hours of hospitalization. There was a statistically significant difference between the CFU numbers of those collected before and after PDT, forcing this intervention to reduce the oral microorganisms of patients admitted to the ICU by an average of approximately 78.6%. Methylene blue in the concentration used without the irradiation of light does not present antimicrobial activity. The following oral fluid brands were named: Pseudomonas aeruginosa, Proteus spp, Klebsiella spp, Escherichia coli, Coagulase negative Staphylococcus, Staphylococcus aureus, Streptococcus spp and Candida albicans. Photodynamic therapy is able to reduce the oral microorganisms of patients hospitalized in ICUs, therefore, it being possible to use this therapy as an alternative means or to oral decontamination, and reduce the possibility of infection development.