Uso profiláctico de antimicrobianos fuera de la práctica quirúrgica y de procedimientos invasivos: bases conceptuales y operativas / Prophylactic use of antimicrobials outside surgical and invasive-procedure settings: conceptual and operational basis

El uso preventivo de antimicrobianos es de larga data y no se restringe a antibacterianos. Lo más consensuado y estructurado es la profilaxis antimicrobiana perioperatoria y ante procedimientos invasivos. Fuera de este contexto hay gran cantidad de situaciones, menos caracterizadas, con riesgo de infecciones en que se usan ampliamente, muchas veces con menor sistematización. Esta presentación presenta las bases conceptuales y operativas de este segundo tipo de profilaxis. Conceptualmente la profilaxis primaria pretende evitar la infección por agente único conocido o variados, por exposición ambiental o susceptibilidad específica de ese hospedero y es implementable antes o después de la exposición. Producida esta infección la meta de la profilaxis secundaria intenta evitar la enfermedad y puede tomar dos modalidades, en infecciones sin evidencias de enfermedad clínica o daños, la profilaxis corresponde a "tratamiento de infección latente" y, si aún en ausencia de manifestaciones clínicas, hay elementos de laboratorio precoces premonitorios de progresión, la profilaxis se denomina "tratamiento anticipatorio". Se presentan operacionalmente y resumidas las situaciones en contexto médico no invasivo con uso potencial preventivo de antimicrobianos en base a agentes posibles, situaciones ambientales de riesgo, vulnerabilidad del hospedero, medicamentos a usar, su duración y efectividad con enfoque mayoritario en medicina de adultos.

Antimicrobial use with preventive purpose probably began shortly after its therapeutic use, especially antibiotics. More consensus and sistematization exist with perioperative and invasive procedures prophylaxis. However, beyond that context, there is great number of non invasive medical situations with high risk of secondary infections either by acquisition of pathogens or activation of latent ones, in which antimicrobials are routinely used with preventive purpose, albeit with less sistematization and consensus. This presentation aims to lay down the conceptual and operational basis for antimicrobial prophylaxis in these settings, whose objective is preventing an infection (primary prophylaxis) by a known or a variety of pathogens, either by person to person transmission, enviromental exposure or particular susceptibility of the host, and can be implemented before or after exposure. If already infected, the antimicrobial prophylaxis goal is to avoid progression to disease (secondary prevention) and may take two conceptual approaches; first, without clinical disease but significant risk of progression, the modality can be called "treatment of latent infection". In the second, also clinically asymptomatic, but with premonitory laboratoy signs of impending progression present, early use of antimicrobial is called "preemptive treatment". This presentation will describe the most frequent medical situations where preventive use of antimicrobials is employed, together with the medications most consensually used, according to the host, the agent(s) and medical situation, with emphasis in adults.

Botulinum toxin type-A effect as a preemptive treatment in a model of acute trigeminal pain: a pre-clinical double-blind and placebo-controlled study / Toxina botulínica do tipo-A no tratamento preemptivo da dor trigeminal aguda: estudo pré-clínico duplo cego placebo controlado

The purpose of this study was to investigate if botulinum neurotoxin type-A (BoNT/A) had a preemptive antinociceptive effect in a formalin-induced orofacial pain model (FT). To test this hypothesis, male Rattus norvegicus were injected with isotonic saline solution 0.9 percent or BoNT/A administered as a 40 μl bolus, lateral to their nose, at 24 hours, 8, 15, 22, 29 or 36 days pre-FT. The procedures were repeated 42 days later. Influence on motor activity was assessed through the open-field test. Pain scores corresponded to the time spent rubbing and flicking the injected area. Animals pre-treated with BoNT/A at the first protocol (8 days subgroup) showed reduced inflammatory scores (p=0.011). For the other groups no significant results were observed at any phase. Motor activity was similar in both groups. BoNT/A showed to be effective preventing inflammatory pain up to eight days after the first treatment, an effect not reproduced on the second dose administration.

O objetivo deste estudo foi investigar o efeito preemptivo da neurotoxina botulínica do tipo/A (NTBo/A) através de um modelo de dor orofacial induzida pelo teste da formalina (TF). Rattus norvegicus machos foram injetados no lábio superior com solução salina isotônica 0,9 por cento (SSI) ou NTBo/A (subgrupos 24 horas, 8, 15, 22, 29 ou 36 dias) antes do TF, em dois tratamentos farmacológicos e respectivas avaliações intercalados por 42 dias. Os escores da dor corresponderam ao tempo de fricção da região injetada. Após o primeiro pré-tratamento com NTBo/A no subgrupo 8 dias os escores da fase inflamatória foram menores do que no grupo SSI (p=0,011). Todas as outras comparações não foram significativas. Nos testes de atividade motora não ocorreram diferenças entre SSI e NTBo/A. A NTBo/A pode ser considerada como tratamento preemptivo das dores orofaciais quando utilizada até oito dias antes do estímulo álgico, não havendo consistência terapêutica após um segundo tratamento.

The clinical evaluation of preemptive treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation / 中华内科杂志

Objective To retrospectively analyze the effect of preemptive treatment on cytomegaloviras (CMV) infection in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods The data of one hundred and three patients who underwent alIo-HSCT with preemptive treatment to prevent CMV associated diseases were retrospectively analyzed. Fluorescence quantitative PCR was used to detect CMV-DNA. The incidences of CMV viremia and CMV associated diseases were analyzed. Results CMV viremia was confirmed 63 times in 51 of the 103 patients. The incidence of CMV viremia was 49. 5% and the median time of onset was 40 days after transplantation. All the patients with CMV viremia received preemptive antiviral therapy and 19 of them developed CMV associated diseases, including 14 hemorrhagic cystitis, 3 CMV associated pneumonia and 2 CMV associated enteritis. The total incidence of CMV associated diseases was 18. 4%. After treatment with ganciclovir and/or foscarnet, 60 of the 63 times of CMV viremia disappeared. One patient was not included in the analysis because he died of intracranial hemorrhage and GVHD only 3 days after the treatment. The total response rate was 96. 8% (60/62). The remaining two cases who did not respond to treatment died of CMV associated pneumonia in combination with acute GVHD. The direct mortality rate of CMV infection was 1.9% (2/103). Conclusion The incidences of CMV viremia and CMV associated diseases do not increase in patients receiving preemptive therapy as compared with those receiving prophylaxis therapy. Preemptive treatment can not only prevent the progression of CMV viremia to CMV associated diseases in majority of the cases but also control CMV associated diseases effectively.