Rediscovering an old friend: the case of Ixodes dampfi in a protected natural reserve in central Mexico.

The tick Ixodes dampfi Cooley 1943, a member of the Pholeoixodes subgenus, was first described from gophers (Geomys sp.) collected in the state of Mexico. However, information on the origin and parasite-host association of I. dampfi is lacking. Here, new records of the occurrence of this tick species were provided nearly 80 years since its original description, in addition to new localities, genetic data, and host-parasite records. A total of four hosts (one Bassariscus astutus, two Didelphis virginiana, and one Peromyscus gratus) from three orders (Carnivora, Didelphimorphia, and Rodentia) were parasitised by seven I. dampfi females. Sequences of the 16S rDNA gene from the ticks exhibited a similarity ranging from 97 (389/403 bp) to 100% (403/403 bp), with the unique sequence of I. dampfi available on GenBank (AF549837). Additionally, Rickettsia-specific 16S rDNA, htrA, and ompA gene assays generated sequences in four of the seven I. dampfi specimens (57.14%). Partial sequences revealed 99-100% genetic identities with Candidatus Rickettsia angustus (GenBank accession HF935069, HF935072, HF935078) and Candidatus Rickettsia kingi (GenBank accession HF935068, HF935071, HF935077) from Canada. Our results represent the first record of this elusive ectoparasite in a natural protected area, which is a triumph for conservation, as accelerated defaunation processes pose the risk of coextinction for many groups of vertebrates and their ectoparasites.

Selection of an actinobacteria mixed culture for chlordane remediation. Pesticide effects on microbial morphology and bioemulsifier production.

Chlordane bioremediation using actinobacteria mixed culture is an attractive clean-up technique. Their ability to produce bioemulsifiers could increase the bioavailability of this pesticide. In order to select a defined actinobacteria mixed culture for chlordane remediation, compatibility assays were performed among six Streptomyces strains. The strains did not show growth inhibition, and they were assayed for chlordane removal, either as pure or as mixed cultures. In pure cultures, all of the strains showed specific dechlorination activity (1.42-24.20 EU mg(-1)) and chlordane removal abilities (91.3-95.5%). The specific dechlorination activity was mainly improved with cultures of three or four microorganisms. The mixed culture consisting of Streptomyces sp. A2-A5-A13 was selected. Their ability to produce bioemulsifiers in the presence of glucose or chlordane was tested, but no significant differences were observed (p > 0.05). However, the stability of the emulsions formed was linked to the carbon source used. Only in chlordane presence the emulsions retained 100% of their initial height. Finally, the selected consortium showed a high degree of sporulation in the pesticide presence. This is the first study on the effects that chlordane exerts on microbe morphology and emulsifier production for a defined mixed culture of Streptomyces with ability to remediate the pesticide.

Applied of actinobacteria consortia-based bioremediation to restore co-contaminated systems.

Global industrialization and natural resources extraction have left cocktails of environmental pollutants. Thus, this work focuses on developing a defined actinobacteria consortium able to restore systems co-contaminated with pollutants occurring in Argentinian environments. In this context, five actinobacteria were tested in solid medium to evaluate antagonistic interactions and tolerance against lindane (LIN), Reactive Black B-V (RBV), phenanthrene (Ph) and Cr(VI). The strains showed absence of antagonism, and most of them tolerated the presence of individual pollutants and their mixtures, except Micromonospora sp. A10. Thus, a quadruple consortium constituted by Streptomyces sp. A5, M7, MC1, and Amycolatopsis tucumanensis DSM 45259T, was tested in liquid systems with individual contaminants. The best microbial growth was observed in the presence of RBV and the lowest on Cr(VI). Removals detected were 83.3%, 65.0% and 52.4% for Ph, RBV and LIN, respectively, with absence of Cr(VI) dissipation. Consequently, the consortium performance was tested against the organic mixture, and a microbial growth similar to the biotic control and a LIN removal increase (61.2%) were observed. Moreover, the four actinobacteria of the consortium survived the mixture bioremediation process. These results demonstrate the potential of the defined actinobacteria consortium as a tool to restore environments co-contaminated with organic pollutants.

The role of synthetic biology in the design of microbial cell factories for biofuel production.

Insecurity in the supply of fossil fuels, volatile fuel prices, and major concerns regarding climate change have sparked renewed interest in the production of fuels from renewable resources. Because of this, the use of biodiesel has grown dramatically during the last few years and is expected to increase even further in the future. Biodiesel production through the use of microbial systems has marked a turning point in the field of biofuels since it is emerging as an attractive alternative to conventional technology. Recent progress in synthetic biology has accelerated the ability to analyze, construct, and/or redesign microbial metabolic pathways with unprecedented precision, in order to permit biofuel production that is amenable to industrial applications. The review presented here focuses specifically on the role of synthetic biology in the design of microbial cell factories for efficient production of biodiesel.

Mycelium-bound lipase production from Aspergillus niger MYA 135, and its potential applications for the transesterification of ethanol.

The potential biotechnological applications of both constitutive and inducible lipase sources from Aspergillus niger MYA 135 were evaluated. To this end, the effect of environmental conditions on mycelium-bound lipase production from this strain was studied, when cultured either in the absence or presence of 2% olive oil. It was previously reported that mycelium-bound lipase from Aspergillus niger MYA 135 possess high stability in reaction mixtures containing ethanol; which could be especially important for their use in biodiesel synthesis. In this connection, the performance of the lipase sources produced in the transesterification of ethanol using p-nitrophenyl palmitate as acyl donor was also explored. Under our assay conditions, hydrolytic and synthetic activity of the mycelia produced in the absence or presence of olive oil were not highly correlated. While the hydrolytic activity was strongly increased by the addition of lipid to the culture medium, the best performance in the transesterification reactions of ethanol were associated with mycelia produced in absence of olive oil. Interestingly, the supplementation of the culture medium with Fe(+3) increased the transesterification activity by 71%, as compared to the activity previously reported for this strain. Therefore, the constitutive lipase sources from Aspergillus niger MYA 135 are considered to be promising for industrial biodiesel-fuel production.

Urban foci of murine typhus involving cat fleas (Ctenocephalides felis felis) collected from opossums in Mexico City.

Murine typhus, a neglected rickettsiosis caused by Rickettsia typhi, is a common disease in several Latin-American countries. The sylvatic life cycle of R. typhi encompasses the presence of several wild mammals, particularly opossums of the genus Didelphis and their associated fleas. Due to the colonization of wild environments by human populations, the increase in contact with opossum fleas has generated the presence of urban outbreaks of typhus. For this reason, the aim of our study was to identify the presence and diversity of Rickettsia sp. in fleas collected from opossums of an urban reserve in Mexico City. Opossums were captured from February to September 2017. For the detection of Rickettsia DNA, fragments of 800 bp of the citrate synthase (gltA) and the outer membrane protein B (ompB) were amplified. A total of 141 fleas (111 ♀, 30 ♂) of a single species (Ctenocephalides felis felis) were recovered from 31 Didelphis virginiana. Rickettsia DNA was detected in 17.7% (25/141) of the analysed fleas, recovered from seven infested opossums. The Maximum likelihood of sequences exhibited an identity of 99%-100% with sequences of R. typhi from southern United States. This work represents the first record of R. typhi in fleas from opossums in Mexico.

Effect of environmental conditions on extracellular lipases production and fungal morphology from Aspergillus niger MYA 135.

Under the current assay conditions, lipase production in mineral medium was only detected in the presence of vegetable oils, reaching the highest specific activity with olive oil. In this way, effect of different environmental conditions on fungal morphology and olive oil-induced extracellular lipases production from Aspergillus niger MYA 135 was studied. It was observed that addition of 1.0 g l(-1) FeCl(3)to the medium encouraged filamentous growth and increased the specific activity 6.6 fold after 4 days of incubation compared to the control. However, major novelty of this study was the satisfactory production of an acidic lipase at initial pH 3 of the culture medium (1.74 +/- 0.06 mU microg(-1)), since its potencial applications in food and pharmaceutical industry are highly promising.

The potential application of an autochthonous fungus from the northwest of Argentina for treatment of sugarcane vinasse.

Vinasse is a waste material from distillery industries, which causes major environmental problems around the world. Argentina alone produces about 4 billion liters of vinasse annually; consequently, diverse biological eco-friendly treatments are evaluated for their ability to reduce the detrimental effects. The present study reports on the degradation of a 50% (v/v) local vinasse sample by an autochthonous fungus identified as Aspergillus sp. V1. The Bioprocess was conducted for 15 d at 30 °C after inoculation of spores at an end concentration of 1 × 106 CFU/mL. Effluent neutralization was detected after 6 d of treatment, with maximum COD and BOD removal after 12 d (49% and 59%, respectively). Effects of vinasse before and after treatment were predicted using Caco-2 cells and Triticum aestivum L. (wheat) seeds as toxicological indicators. Only 13% viability was observed for Caco-2 cells exposed to untreated vinasse, but this percentage increased more than 3-fold for cells exposed to the treated effluent. While vinasse without treatment completely inhibited germination of seeds, exposure to treated effluent demonstrated a germination percentage of 60%. The present study highlights the use of a dual-purpose biotechnological process that aimed at reducing the detrimental effects of vinasse, enhancing its quality for agricultural practices.

Production of a microbial emulsifier with biotechnological potential for environmental applications.

The present work reports the production of bioemulsifiers (BEs) by an environmental bacterium closely related to Bacillus spp., using agro-industrial wastes and by-products as low-cost carbon sources. Maximum emulsifying activity was detected using crude glycerol (CG) (E24 = 59%), producing 2.8 g/L of BE at 24 h of incubation. The microbial product presented significantly higher biodegradability in comparison to three commercial emulsifying agents (sodium dodecyl sulfate, SDS; Tween 80; and Arabic gum, AG). Interestingly, BE proved to be innocuous for Caco-2 cells and wheat seedlings, used as toxicological indicators. The BE and AG showed (in most of the cases) higher stability to changes in temperature (37 °C-100 °C), pH (3-10), and salt concentration (5% and 10%, w/v) in comparison to the SDS and Tween 80. Finally, the microbial product displayed a large affinity to a wide range of hydrophobic substrates showing emulsifying activities similar to or even better than SDS, Tween 80 and AG. The results presented in this study demonstrate the potential of a bioproduct obtained from CG to be used for environmental purposes.

[Quality of life in patients with continuous ambulatory peritoneal dialysis]. / Calidad de vida en pacientes con diálisis peritoneal continua ambulatoria.

OBJECTIVE: To evaluate different aspects of the quality of life of patients with continuous ambulatory peritoneal dialysis, using the survey SF-36 (Medical Outcomes Study 36-Short Form Health Survey). METHODOLOGY: A cross-sectional study was carried out with patients older than 18 years having chronic renal failure and being registered in the continuous ambulatory peritoneal dialysis program in the last three months. A sample size of 48 patients was estimated. The version 1.1 of the SF-36 survey previously adapted for Mexican people was used to evaluate quality of life. RESULTS: Forty-eight patients were included, among which 52% were males, the mean of age was 45 years old. All eight domains of health were analyzed. The role limitations due to physical health showed the lower score (mean = 19.79; men: 13, women: 27.1) while mental health showed the higher (mean = 61.66; men: 59.68 women: 63.83).

Integral use of sugarcane vinasse for biomass production of actinobacteria: Potential application in soil remediation.

The use of living actinobacteria biomass to clean up contaminated soils is an attractive biotechnology approach. However, biomass generation from cheap feedstock is the first step to ensure process sustainability. The present work reports the ability of four actinobacteria, Streptomyces sp. M7, MC1, A5, and Amycolatopsis tucumanensis, to generate biomass from sugarcane vinasse. Optimal vinasse concentration to obtain the required biomass (more than 0.4 g L-1) was 20% for all strains, either grown individually or as mixed cultures. However, the biomass fraction recovered from first vinasse was discarded as it retained trace metals present in the effluent. Fractions recovered from three consecutive cycles of vinasse re-use obtained by mixing equal amounts of biomass from single cultures or produced as a mixed culture were evaluated to clean up contaminated soil with lindane and chromium. In all cases, the decrease in pesticide was about 50% after 14 d of incubation. However, chromium removal was statistically different depending on the preparation methodology of the inoculum. While the combined actinobacteria biomass recovered from their respective single cultures removed about 85% of the chromium, the mixed culture biomass removed more than 95%. At the end of the reused vinasse cycle, the mixed culture removed more than 70% of the biological oxygen demand suggesting a proportional reduction in the effluent toxicity. These results represent the first integral approach to address a problematic of multiple contaminations, concerning pesticides, heavy metals and a regionally important effluent like vinasse.

Actinobacteria: Current research and perspectives for bioremediation of pesticides and heavy metals.

Actinobacteria exhibit cosmopolitan distribution since their members are widely distributed in aquatic and terrestrial ecosystems. In the environment they play relevant ecological roles including recycling of substances, degradation of complex polymers, and production of bioactive molecules. Biotechnological potential of actinobacteria in the environment was demonstrated by their ability to remove organic and inorganic pollutants. This ability is the reason why actinobacteria have received special attention as candidates for bioremediation, which has gained importance because of the widespread release of contaminants into the environment. Among organic contaminants, pesticides are widely used for pest control, although the negative impact of these chemicals in the environmental balance is increasingly becoming apparent. Similarly, the extensive application of heavy metals in industrial processes lead to highly contaminated areas worldwide. Several studies focused in the use of actinobacteria for cleaning up the environment were performed in the last 15 years. Strategies such as bioaugmentation, biostimulation, cell immobilization, production of biosurfactants, design of defined mixed cultures and the use of plant-microbe systems were developed to enhance the capabilities of actinobacteria in bioremediation. In this review, we compiled and discussed works focused in the study of different bioremediation strategies using actinobacteria and how they contributed to the improvement of the already existing strategies. In addition, we discuss the importance of omic studies to elucidate mechanisms and regulations that bacteria use to cope with pollutant toxicity, since they are still little known in actinobacteria. A brief account of sources and harmful effects of pesticides and heavy metals is also given.

Potential application of a bioemulsifier-producing actinobacterium for treatment of vinasse.

Vinasse is a complex effluent created during production of ethyl alcohol, which can present serious pollution hazard in areas where it is discharged. A variety of technologies, many based upon recovery of the effluent via microbial pathways, are continually being evaluated in order to mitigate the pollution potential of vinasse. The present work reports on initial advances related to the effectiveness of the actinobacterium Streptomyces sp. MC1 for vinasse treatment. Alternative use of raw vinasse as a substrate for producing metabolites of biotechnological interest such as bioemulsifiers, was also evaluated. The strain was able to grow at very high vinasse concentrations (until 50% v/v) and remove over 50% of the biodegradable organic matter in a time period as short as 4 d. Potentially toxic metals such as Mn, Fe, Zn, As, and Pb were also effectively removed during bacterial growth. Decrease in the pollution potential of treated vinasse compared to raw effluent, was reflected in a significant increase in the vigour index of Lactuca sativa (letucce) used as bioremediation indicator. Finally, significant bioemulsifier production was detected when this strain was incubated in a vinasse-based culture medium. These results represent the first advances on the recovery and re-valuation of an actual effluent, by using an actinobacterium from our collection of cultures.

Tailoring fungal morphology of Aspergillus niger MYA 135 by altering the hyphal morphology and the conidia adhesion capacity: biotechnological applications.

Current problems of filamentous fungi fermentations and their further successful developments as microbial cell factories are dependent on control fungal morphology. In this connection, this work explored new experimental procedures in order to quantitatively check the potential of some culture conditions to induce a determined fungal morphology by altering both hyphal morphology and conidia adhesion capacity. The capacity of environmental conditions to modify hyphal morphology was evaluated by examining the influence of some culture conditions on the cell wall lytic potential of Aspergillus niger MYA 135. The relative value of the cell wall lytic potential was determined by measuring a cell wall lytic enzyme activity such as the mycelium-bound ß-N-acetyl-D-glucosaminidase (Mb-NAGase). On the other hand, the quantitative value of conidia adhesion was considered as an index of its aggregation capacity. Concerning microscopic morphology, a highly negative correlation between the hyphal growth unit length (lHGU) and the specific Mb-NAGase activity was found (r = -0.915, P < 0.001). In fact, the environment was able to induce highly branched mycelia only under those culture conditions compatible with specific Mb-NAGase values equal to or higher than 190 U gdry.wt-1. Concerning macroscopic morphology, a low conidia adhesion capacity was followed by a dispersed mycelial growth. In fact, this study showed that conidia adhesion units per ml equal to or higher than 0.50 were necessary to afford pellets formation. In addition, it was also observed that once the pellet was formed the lHGU had an important influence on its final diameter. Finally, the biotechnological significance of such results was discussed as well.

Production and partial characterization of bioemulsifier from a chromium-resistant actinobacteria.

Surface-active compounds such as synthetic emulsifiers have been used for several decades, both for the degradation of hydrocarbons and increasing desorption of soil-bound metals. However, due to their high toxicity, low degradability, and production costs unaffordable for use in larger ecosystems, synthetic emulsifiers have been gradually replaced by those derived from natural sources such as plants or microbes. In previous studies, the bacterium Streptomyces sp. MC1 has shown the ability to reduce and/or accumulate Cr(VI), a highly promising advance in the development of methods for environmental clean-up of sites contaminated with chromium. Here, new studies on the production of emulsifier from this strain are presented. The cultivation factors that have a significant influence on emulsifier biosynthesis, as well as the interactions among them, were studied by factorial design. Based upon optimization studies, maximum bioemulsifier production was detected in the culture medium having an initial pH of 8 with phosphate 2.0 g L(-1) and Ca(+2) 1.0 g L(-1) added, with an emulsification index about 3.5 times greater compared to the basal value. Interestingly, in the presence of 5.0 g L(-1) Cr(VI), Streptomyces sp. MC1 retained about 65% of its emulsifier production ability. Partially purified emulsifier presented high thermo-stability and partial water solubility. These findings could have promising future prospects for the remediation of organic- and metal-contaminated sites.

Production of bioemulsifiers by Amycolatopsis tucumanensis DSM 45259 and their potential application in remediation technologies for soils contaminated with hexavalent chromium.

In recent years, increasing interest has been shown in the use of bioemulsifiers as washing agents that can enhance desorption of soil-bound metals. However, high production costs derived from the use of expensive substrates for formulation of the fermentation media represent the main challenge for full, large-scale implementation of bioemulsifiers. This work reports on a first study of bioemulsifier production by the actinobacterium Amycolatopsis tucumanensis DSM 45259 using different carbon and nitrogen sources. Preliminary results on the potential use of these compounds as washing agents for soils contaminated with Cu(II) and Cr(VI) are also presented. The best specific production was detected using glycerol and urea as carbon and nitrogen substrates, respectively. However, with all of the substrates used during the batch assay, the bioemulsifiers showed high levels of stability at extreme conditions of pH, temperature, and salt concentration. Under the current assay conditions, the bioemulsifiers were not effective in removing Cu(II) from soil. However, they were able to mediate Cr(VI) recovery, with the removal percentage doubled compared to that seen when using deionized water. These findings appear promising for the development of remediation technologies for hexavalent chromium compounds based upon direct use of these microbial emulsifiers.

[Acute asthma and its costs of care at an emergency service]. / Agudizaciones del asma y sus costos de atención en el servicio de urgencias.

BACKGROUND: The request in the urgency service for attention in acute asthma is determined by multiple factors as the medical handling, the constancy and the pursuance of the patient in the adequate follow up of the treatment, the climate, the food hygienic habits and the allergies. OBJECTIVE: To determine in one year period, the frequency, recurrence of medical attention for acute asthma and the cost in the hospital urgency service of second level in medical attention. MATERIAL AND METHODS: We made an analysis of a secondary study done in 1999 in pediatric patients younger than 16 years with diagnosis of acute asthma. RESULTS: From 6,912 consultations given in the pediatric emergency area, 2,586 were from acute asthma, the half was 5.2 years old patients, the minimal average time a patient had to stay in the hospital per month was of 7.36 hours in January and the maximum average time was of 22.10 hours in the month of September. Regarding the frequency of attendance in the service for a new event, the following distribution was found: from two to three 25.72%, from 4 to 6 10.1% and from 7 to 15 0.96%. The cost of the attention had a total cost of 5'787,494.82 pesos. CONCLUSIONS: The frequency of acute asthma was 41.58% and this figure was considered high in comparison to similar studies. The clinic evolution and the treatment response are related to the age, and, in the study results, the patients younger than 3 years had a longer stay in the hospital, also, there was an increase of patients in the rainy months. The frequency of patients who assisted between 2 or 3 times and the cost was 387,123.00 pesos. That frequency may be due to patients did not receive a long-term treatment provision, or because of ignorance in the initial rescue treatment, ignorance in the factors that raise the sickness, as well as patients not taking their treatment the way it was asked by the doctors. These factors increase the cost, which is feasible to be modifyied, if the patients and their families get acknowledge on the importance of respecting the instructions on the proper way of treating the acute asthma, and all the triggering factors of it.

Identificación de mecanismos de transmisión del virus papiloma humano en mujeres infectadas / Identification of transmission mechanisms for human papilloma virus (HPV) in infected women

Introducción: El virus del papiloma humano, es uno de los más frecuentes de trasmisión sexual y conocer los mecanismos de transmisión tiene vital importancia para el control de la incidencia de esta enfermedad. Objetivo: Evaluar el nivel de conocimientos de las pacientes con virus del papiloma humano, sobre los mecanismos de transmisión. Metodología: Se incluyeron 109 pacientes subsecuentes y de primera vez que acudieron a la clínica de displasias por diagnóstico de VPH. Para evaluar el nivel de conocimiento, se consideraron tres indicadores: Bueno (>20 aciertos), Regular (16-20 aciertos) y Malo (≤15 aciertos). El cuestionario fue validado por rondas de expertos. Resultados: Del total de pacientes 31.2% tuvo conocimiento bueno, 42.2% regulary 26.6% malo. De 109 pacientes47.7% son de estrato socioeconómico medio bajo, 49.5% con estudios de primaria, casadas 67%, con una pareja sexual 54.1%, con vida sexual activa 44% y 77.1 % no habían recibido pláticas informativas en relación al virus del papiloma humano. Conclusiones: Es evidente la necesidad de implementar nuevas y diversas estrategias dirigidas a la población afectada encaminadas al aprendizaje de los mecanismos de transmisión para incrementar su nivel de conocimiento y coadyuvar en el control de la propagación del virus.

Introduction: HPV is one of the most often sexual transmitted diseases, and knowing the transmission mechanisms is vital to control the incidence of this infection. Objective: To evaluate the level of knowledge regarding transmission mechanisms in patients with HPV infection. Methodology: 109 first timers and subsequent patients who showed up to the Displasias Clinic for diagnosis of HPV were included in the study. To evaluate the level of knowledge, three indicators were considered; good (>20 items answered correctly), regular (16-20 items answered correctly), and bad (= or < 15 items answered correctly). The questionnaire was validated by review of experts. Results: From the total, 31.2% patients had good, 42.2% regular, and 26.6% bad knowledge. 47.7% out of 109 patients are half low socioeconomic status; 49.5% with elementary school of education; 67% got married; 54.1% with a single sexual partner; 44% sexual actives; and 77.1% had not received any sort of information talks regarding HPV. Conclusions: It is evident the necessity of implementing new and diverse strategies lead to affected population through learning the transmission mechanisms to increase their level of knowledge and collaborate in the control of virus spreading.

Infusión epidural de fentanyl/bupivacaína por medio de infusor elastomérico para control de dolor postoperatorio / Epidural infusion of Fentanyl/bupivacaine using elastomeric infusor for postoperative analgesia

El empleo de mezclas de opioides y anestésicos locales a bajas concentraciones para ser administrados en infusión epidural proporciona analgesia efectiva con mínimos efectos colaterales. 40 pacientes ginecobstétricas en su postoperatoria inmediato fueron divididas en dos grupos: El grupo 1 (22 pacientes) recibió analgesia postoperatoria con infusión epidural mediante dispositivos elastomérico de 2 ml/hora de una mezcla de bupivacaína al 0.125 por ciento y fentanyl 6.25 µg/ml por un lapso de 24 horas. El grupo 2 (18 pacientes) recibió analgesia convencional con analgésicos del tipo AINE. En ambos grupos se indicó meperidina I.M. (PRN) 50 a 75 mg como analgesia de rescate. Se realizó la evaluación del dolor mediante escala visual análoga (EVA) a las 1.5, 8 y 24 horas. Se registraron efectos secundarios, inicio de ambulación y satisfacción con el método analgésico. Se efectuó análisis estadístico mediante la prueba de U de Mann-Whitney para evaluar mediciones de dolor por EVA. Las pacientes del grupo 1 mostraron puntajes de EVA significativamente favorables al compararse con las del grupo 2, con una menor incidencia de efectos colaterales indeseables, mayor satisfacción con el método analgésico empleado y mínima utilización de rescate

Modificaciones de la presión intraocular con la administración de clonidina vía oral y su asociación con bloqueo peribulbar en el paciente geriátrico / Intraocular pressure modifications with the administration of oral clonidine and its asociation with peribulbar block in geriatric patient

Los ancianos con frecuencia son sometidos a cirugía oftálmica ambulatorias que, debido a la complejidad técnica, requieren de un paciente cooperador, así como adecuado control hemodinámico y de la presión intraocular. Una técnica que ha demostrado utilidad es la asociación de anestesia local con sedación. La clonidina es un agonista alfa 2 recomendado por sus efectos ansiolíticos, sedantes, antieméticos, hipotensor y de disminución en la presión intraocular. El objetivo del estudio fue evaluar el efecto de la clonidina sobre la presión intraocular y su asociación con el bloqueo peribulbar en pacientes mayores de 65 años. Material y métodos: Se estudiaron 20 pacientes mayores de 65 años programados para cirugía de extracción de catarata con colocación de lente intraocular; a los que se administró medicación preanestésica con clonidina 1.5 µg/kg 90 minutos antes de la cirugía. Se utilizó monitorización no invasiva, de acuerdo a estándares ASA: Se colocó bloqueo peribulbar y se administró 1 mg de midazolam más 50 µg de fentanil por vía intravenosa. Se midió la presión con tonómetro eléctrico basal, con clonidina y clonidina más bloqueo peribulbar. Los valores de signos vitales y presión intraocular se analizaron con la prueba análisis de varianza de mediciones repetidas (P= 0.05). Resultados: La edad promedio fue de 74.7 (ñ 7.9) años, la presión arterial media disminuyó significativamente, lo mismo que la presión intraocular; en la frecuencia cardiaca no hubo diferencia estadísticamente significativa. Discusión: La clonidina a dosis de 1.5 µg/kg disminuye la presión intraocular de manera significativa, probablemente debido a la disminución de la presión arterial media; sin embargo, la presión intraocular dimminuyó aún más al asociarse con bloqueo peribulbar. No existieron efectos secundarios importantes con el uso de esta dosis de clonidina en pacientes ancianos