RESUMEN
BACKGROUND: Glomus tumours (GTs) are benign cutaneous neoplasms derived from the neuromyoarterial apparatus with a strong predilection for acral sites, especially the subungual space. Current data regarding dermoscopy of these lesions are very limited. OBJECTIVES: To analyse the dermoscopic structures and patterns seen in a large series of subungual (SUGTs) and extraungual glomus tumours (EUGTs) and to determine their diagnostic significance. METHODS: Clinical and dermoscopic images of 86 histopathologically proven cases of GTs (47 SUGTs and 39 EUGTs) collected from 9 hospitals in Spain, France, Italy, and Brazil were evaluated for the presence of dermoscopic structures and patterns. Similarly, 189 and 185 dermoscopic images of other ungual tumours and other extraungual non-pigmented tumours, respectively, were evaluated for the same structures and patterns. Finally, we evaluate diagnostic testing accuracy calculating sensitivity (S), specificity (Sp), and positive and negative predictive values of the different patterns for the diagnosis of GT. RESULTS: Regarding SUGTs, four patterns were built from the combination of different structures. The pattern composed of a structureless purplish/red subungual spot with or without vessels reached the highest S (S1, 78.8%). The combination of a structureless purplish/red subungual spot and longitudinal erythronychia (LE) (S2) is highly specific (96.3%). Patterns S3 (proximal purplish/red subungual spot, LE, and distal notch) and S4 (bed subungual spot and onycholysis) are the most specific and exclusive of matrix and bed tumours, respectively. The most consistent pattern in EUGTs is composed of a structureless purplish-white to reddish-white homogeneous area and linear unfocused vessels (E) (S: 61.5%, Sp: 95.7%). EUGTs did not show lacunae, unlike other vascular tumours. CONCLUSIONS: Dermoscopy is helpful in improving the diagnostic accuracy of GTs, not only in SUGTs but also when these lesions arise out of the ungual apparatus.
Asunto(s)
Tumor Glómico , Onicólisis , Neoplasias Cutáneas , Estudios Transversales , Dermoscopía/métodos , Tumor Glómico/diagnóstico por imagen , Humanos , Neoplasias Cutáneas/diagnóstico por imagen , Neoplasias Cutáneas/patologíaRESUMEN
Antimony is a toxic element whose concentration in soil and water has been rising due to anthropogenic activities. This study focuses on its accumulation in leaves of Dittrichia viscosa growing in soils of an abandoned Sb mine, and the effect on oxidant/antioxidant systems and photosynthetic efficiency. The results showed leaves to have a high Sb accumulation capacity. The amount of total chlorophyll decreased depending on Sb concentration and of carotenoids increased slightly, with a consequent increase in carotenoid/chlorophyll ratio. Photosynthetic efficiency was unaffected. The amount of O 2 .- rose, although there was no increase in cell membrane damage, with lipid peroxidation levels being similar to normal. This response may be due to considerable increases that were observed in total phenolics, PPO activity, and enzymatic antioxidant system. SOD, POX, and DHAR activities increased in response to increased Sb amounts in leaves. The ascorbate/glutathione cycle was also affected, with strong increases observed in all of its components, and consequent increases in total contents of the ascorbate and glutathione pools. However, the ratio between reduced and oxidized forms declined, reflecting an imbalance between the two, especially that between GSH and GSSG. Efficient detoxification of Sb may take place either through increases in phenolics, carotenoids, and components of the glutathione-ascorbate cycle or through the enzymatic antioxidant system. Since Dittrichia viscosa accumulates large amounts of Sb without suffering oxidative damage, it could be used for phytoremediation.
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Antimonio/toxicidad , Antioxidantes/metabolismo , Asteraceae/fisiología , Hojas de la Planta/metabolismo , Contaminantes del Suelo/toxicidad , Antimonio/análisis , Ácido Ascórbico/metabolismo , Asteraceae/efectos de los fármacos , Biodegradación Ambiental , Clorofila/metabolismo , Glutatión/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Minería , Estrés Oxidativo/efectos de los fármacos , Fenoles/metabolismo , Fotosíntesis/efectos de los fármacos , Pigmentos Biológicos/metabolismo , Hojas de la Planta/química , Hojas de la Planta/efectos de los fármacos , Suelo/química , Contaminantes del Suelo/análisis , EspañaRESUMEN
BACKGROUND: A variety of cutaneous smooth muscle neoplasms may arise in the skin and are frequently unrecognized by clinicians. There is sparse data relating to the dermoscopy of piloleiomyomas (PL), and nothing has been published about the dermoscopy of angioleiomyomas (AL) and leiomyosarcomas (LS). OBJECTIVES: To evaluate the morphological findings of a large series of cutaneous PL, AL and LS under dermoscopic observation, comparing these findings among them. METHODS: Digital dermoscopic images of 136 histopathologically confirmed cases of cutaneous smooth muscle neoplasms (114 PL, 13 AL and 9 LS) collected from 10 Hospitals in Spain, Austria and Italy were evaluated for the presence of dermoscopic structures and patterns. RESULTS: The pattern composed of a symmetric, total delicate pigment network with the variable presence of multiple hypopigmented areas in a painful lesion is the most common dermoscopic pattern associated with PL. This pattern was found in 69.3% of PL and in no cases of AL and LS. The most common and characteristic pattern associated with AL was the one composed of symmetric pink-reddish tumour with vessels, white structures and the absence of ulceration, which was found in 46.2% of AL, but also in 3.5% of PL, and in 22.2% of LS. Finally, the most common pattern associated with LS was the one composed of an asymmetric, multilobulated tumour with linear-irregular or polymorphic-atypical vessels and white structures, which was found in 44.4% of cases, but also in 0.9% of PL and in 15.4% of AL. CONCLUSION: Dermoscopy is helpful in improving the diagnostic accuracy of PL. The dermoscopic patterns associated with AL and LS were more variable and less specific.
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Angiomioma/diagnóstico por imagen , Dermoscopía , Leiomiosarcoma/diagnóstico por imagen , Neoplasias Cutáneas/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo LisoRESUMEN
The strongyloidiasis is an infection whose responsible agents are Strongyloides stercoralis and S. fuelleborni. These nematodes have an intestinal location; the main risk factor is to be barefoot in places contaminated with filariform larvae. The study presents a male 23-year-old resident of San Juan de Lurigancho, with 14 months of illness with signs of bloating, nausea, vomiting and wasafebrile,also indicates that 28 days before he had epigastric pain irradiated to the back. On physical examination a distended abdomen was found, soft painful tympanic tenderness, the abdominal ultrasonography showed dilated bowel loops, bloat, with abundant presence of free fluid in the abdominal cavity (ascites) and parasitological examinations observed, rabditoides larvae L1 and L2 and filariform L3 of Strongyloides stercoralis. He received Ivermectin, obtaining the patient's recovery.
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Líquido Ascítico/parasitología , Strongyloides stercoralis/aislamiento & purificación , Estrongiloidiasis/parasitología , Animales , Humanos , Masculino , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
Melanoma in individuals with oculocutaneous albinism has been reported in the literature to be rare compared with the more common occurrence of squamous cell carcinoma and basal cell carcinoma. We present a singular case of amelanotic naevoid melanoma arising from a small congenital naevus in a 16-month old albino boy, the youngest reported to date.
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Albinismo Oculocutáneo/complicaciones , Melanoma Amelanótico/complicaciones , Nevo/complicaciones , Piel/patología , Albinismo Oculocutáneo/diagnóstico , Procedimientos Quirúrgicos Dermatologicos/métodos , Humanos , Lactante , Masculino , Melanoma Amelanótico/diagnóstico , Melanoma Amelanótico/cirugía , Nevo/congénito , Nevo/cirugíaRESUMEN
The late development of symmetrical, ascending telangiectasias over an extensive area of the skin with no associated systemic manifestations is a common presentation of generalized essential telangiectasia (GET). It was recently suggested that cutaneous collagenous vasculopathy (CCV) is clinically identical to GET but that the 2 conditions can be distinguished by their distinctive histopathologic findings. We present 2 patients, both women, with multiple telangiectasias and describe the histopathologic findings that led to the diagnoses of GET and CCV. Dermoscopic findings in both cases were similar, except that the older telangiectasias in the patient with CCV were violaceous and distributed in a tortuous, serpentine pattern. During follow-up 12 years for the woman with GET and 42 years for the woman with CCV we saw that in GET the lesions remained stable in appearance whereas in CCV there was progressive darkening and morphological changes eventually resulting in superficial varicose veins.
Asunto(s)
Enfermedades Cutáneas Vasculares/patología , Telangiectasia/patología , Anciano de 80 o más Años , Colágeno , Femenino , Humanos , Persona de Mediana EdadRESUMEN
BACKGROUND AND OBJECTIVES: Jellyfish are free-living members of the phylum Cnidaria who share a specialized stinging cell, the cnidocyte. Pelagia noctiluca is the most frequent and toxic jellyfish species found in the Balearic beaches and cnidocytes are arranged in pigmented clusters called "warts". Dermoscopy continues to expand its use much beyond the pigmentary lesions and to date, there is no data regarding dermoscopic findings in jellyfish stings. The aim of the present work was to study the dermoscopic findings of jellyfish stings in the island of Mallorca. PATIENTS AND METHODS: We retrospectively reviewed the clinical and dermoscopic images of 25 episodes of jellyfish stings caused by P. noctiluca that occurred between 2009 and 2015. RESULTS: Overall, the following dermoscopic features were found: brown dots (84%), pinkish hue (56%), pinpoint brown crusts (44%), scale-crust (40%), brown "Chinese characters pattern" (32%), "serpentine" ulceration (28%), linear purpura (20%), and whitish-yellow crusts (15%). Vessels were mainly dotted (36%) or reticular (16%). Scale-crust, serpentine ulceration and pinkish hue were significantly more frequent in lesions older than 2 days. CONCLUSIONS AND LIMITATIONS: Our study identifies 4 dermoscopic features that may represent the contact with P. noctiluca cnidocytes: brown dots, brown "Chinese characters pattern", pinpoint brown crusts and whitish-yellow crusts. A peculiar finding of "serpentine ulceration" with brown dots would be very suggestive of P. noctiluca sting. We believe dermoscopy is a valuable tool in the diagnosis of jellyfish stings when a clear history of contact is lacking. Further studies are needed to validate our findings in other jellyfish species.
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Mordeduras y Picaduras/patología , Dermoscopía , Escifozoos , Adolescente , Adulto , Anciano , Animales , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE: To perform a cost-effectiveness and cost-utility analysis of ingenol mebutate in the treatment of actinic keratosis in Spain. METHODS: We used an adapted Markov model to simulate outcomes in a cohort of patients (mean age, 73 years) with actinic keratosis over a 5-year period. The comparators were diclofenac 3% and imiquimod 5%. The analysis was performed from the perspective of the Spanish National Health System based on direct costs (2015 retail price plus value added tax less the mandatory discount). A panel of experts estimated resources, taking unit costs from national databases. An annual discount rate of 3% was applied. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: The effectiveness of ingenol mebutate-with 0.192 and 0.129 more clearances gained in treatments for face and scalp lesions and trunk and extremity lesions, respectively-was superior to diclofenac's. The total costs of treatment with ingenol mebutate were lower at 551.50 (face and scalp) and 622.27 (trunk and extremities) than the respective costs with diclofenac ( 849.11 and 844.93). The incremental cost-effectiveness and cost-utility ratios showed that ingenol mebutate was a dominant strategy vs diclofenac. Ingenol mebutate also proved to be more effective than imiquimod, based on 0.535 and 0.503 additional clearances, and total costs of 551.50 and 527.89 for the two drugs, respectively. The resulting incremental cost-effectiveness ratio was 728.64 per clearance gained with ingenol mebutate vs imiquimod. CONCLUSIONS: Ingenol mebutate was a dominant treatment option vs diclofenac and was efficient vs imiquimod (i.e., more effective at a higher cost, achieving an incremental cost-utility ratio of<30000/quality-adjusted life-years).
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Aminoquinolinas/administración & dosificación , Aminoquinolinas/economía , Análisis Costo-Beneficio , Diclofenaco/administración & dosificación , Diclofenaco/economía , Diterpenos/economía , Diterpenos/uso terapéutico , Queratosis Actínica/tratamiento farmacológico , Queratosis Actínica/economía , Anciano , Humanos , Imiquimod , EspañaRESUMEN
BACKGROUND: Naevus sebaceous is a congenital hamartoma commonly associated with the development of secondary neoplasms. There are sparse data relating to the dermoscopy of tumours arising in naevus sebaceous. OBJECTIVES: To evaluate the dermoscopic features of a large series of neoplasms arising in naevus sebaceous. METHODS: Digital dermoscopic images of 58 histopathologically confirmed cases of secondary neoplasms arising in naevus sebaceous collected from 11 hospitals in Spain, France, Italy and Austria were evaluated for the presence of dermoscopic structures and patterns. RESULTS: The most frequent tumours collected were: trichoblastoma (39.6%), basal cell carcinoma (20.7%) and syringocystadenoma papilliferum (15.6%). The most remarkable findings were: (i) the pattern composed of asymmetrical large blue-grey ovoid nests was more common in basal cell carcinomas than in trichoblastoma (58.3% vs. 4.3%; P < 0.001) and the pattern composed of a symmetrical total large blue-grey ovoid nest (a blue-grey homogeneous area which occupies the whole lesion) was more common in trichoblastoma (82.6% vs. 16.6%; P < 0.001); (ii) the most frequent pattern associated with syringocystadenoma papilliferum was a symmetric, erythematous lesion with exophytic papillary structures, ulceration and vessels (55.5%); (iii) the most common pattern associated with apocrine hidrocystomas was a total symmetric homogeneous area and arborizing telangiectasias (60%). CONCLUSIONS: Benign adnexal tumours associated with naevus sebaceous are dermoscopic mimickers of basal cell carcinomas. A pigmented nodule arising in a naevus sebaceous with a total blue large ovoid nest on dermoscopy could be a trichoblastoma, basal cell carcinoma, hidrocystoma or hidradenoma. Dermoscopy can be a useful diagnostic tool which generates a more accurate preoperative diagnosis.
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Acrospiroma/patología , Carcinoma Basocelular/patología , Cistoadenoma/patología , Hidrocistoma/patología , Nevo Sebáceo de Jadassohn/patología , Neoplasias de las Glándulas Sebáceas/patología , Neoplasias de las Glándulas Sudoríparas/patología , Adolescente , Adulto , Anciano , Transformación Celular Neoplásica/patología , Niño , Dermoscopía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Most studies on dermoscopy of acral lesions were conducted in Asian populations. In this study, we analyzed these features in a predominantly Caucasian population. OBJECTIVE: Estimate the prevalence of dermoscopic features in acral lesions, and assess their level of agreement between observers. METHODS: In this retrospective multicenter study, 167 acral lesions (66 melanomas) were evaluated for 13 dermoscopic patterns by 26 physicians, via a secured Internet platform. RESULTS: Parallel furrow pattern, bizarre pattern, and diffuse pigmentation with variable shades of brown had the highest prevalence. The agreement for lesion patterns between physicians was variable. Agreement was dependent on the level of diagnostic difficulty. CONCLUSION: Lesions with a diameter >1 cm were more likely to be melanoma. We found as well that a benign pattern can be seen in parts of melanomas. For this reason one should evaluate an acral lesion for the presence of malignant patterns first.
Asunto(s)
Dermoscopía , Melanoma/patología , Variaciones Dependientes del Observador , Neoplasias Cutáneas/patología , Actitud del Personal de Salud , Biopsia , Humanos , Internet , Estudios Retrospectivos , Sociedades Médicas , Población BlancaRESUMEN
Wastes derived from the exploitation of stibnite ore deposits were studied to determine their mineralogical, chemical, and environmental characteristics and establish the Sb distribution and the current and long-term risks of Sb mobilization. Representative samples of mine waste rocks, mine tailings, and smelting waste were studied by X-ray powder diffraction, polarized light microscopy, electron microprobe analysis, and digestion, leaching, and extraction procedures. The main Sb-bearing minerals and phases identified in the smelting waste were natrojarosite, iron (oxyhydr)oxides, mixtures of iron and antimony (oxyhydr)oxides, and tripuhyite; those in the mine tailings and mine waste rocks were iron (oxyhydr)oxides and/or mixtures of iron and antimony (oxyhydr)oxides. Iron (oxyhydr)oxides and natrojarosite had high Sb contents, with maximum values of 16.51 and 9.63 wt% Sb2O5, respectively. All three types of waste were characterized as toxic; the mine waste rocks and mine tailings would require pretreatment to decrease their leachable Sb content before they would be acceptable at hazardous waste landfills. Relatively little of the Sb was in desorbable forms, which accounted for <0.01 and <0.8% of the total Sb content in the smelting waste and mine waste rocks/mine tailings, respectively. Under reducing conditions, further Sb mobilization from mine waste rocks and mine tailings could occur (up to 4.6 and 3.3% of the total content, respectively), considerably increasing the risk that Sb will be introduced into the surroundings. Although the smelting waste had the highest total Sb content, it showed the lowest risk of Sb release under different environmental conditions. The significant Fe levels in the smelting waste facilitated the formation of various Fe compounds that greatly decreased the Sb mobilization from these wastes.
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Antimonio , Minerales , Antimonio/análisis , Residuos Peligrosos , Hierro , ÓxidosAsunto(s)
Dermatofibrosarcoma/cirugía , Cirugía de Mohs , Neoplasias Cutáneas/cirugía , Niño , Humanos , MasculinoAsunto(s)
Úlcera del Pie/microbiología , Radiodermatitis/complicaciones , Vibriosis/etiología , Vibrio alginolyticus/aislamiento & purificación , Anciano , Enfermedades del Pie/etiología , Úlcera del Pie/etiología , Humanos , Masculino , Huesos Metatarsianos/diagnóstico por imagen , Huesos Metatarsianos/microbiología , Osteomielitis/diagnóstico por imagen , Osteomielitis/etiología , Agua de Mar/microbiología , España , Vibriosis/diagnóstico por imagen , Microbiología del AguaRESUMEN
The consensus statement on the management of primary cutaneous melanoma that we present here was based on selection, discussion, review, and comparison of recent literature (including national and international guidelines). The protocols for the diagnosis, treatment, and follow-up used in the hospital centers throughout Catalonia and the Balearic Isles belonging to the Network of Catalan and Balearic Melanoma Centers were also considered. The main objective of this statement was to present the overall management of melanoma patients typically used in our region at the present time. As such, the statement was not designed to be an obligatory protocol for health professionals caring for this group of patients, and neither can it nor should it be used for this purpose. Professionals reading the statement should not therefore consider it binding on their practice, and in no case can this text be used to guarantee or seek responsibility for a given medical opinion. The group of dermatologists who have signed this statement was created 3 years ago with the aim of making our authorities aware of the importance of this complex tumor, which, in comparison with other types of cancer, we believe does not receive sufficient attention in Spain. In addition, the regular meetings of the group have produced interesting proposals for collaboration in various epidemiological, clinical, and basic applied research projects on the subject of malignant melanoma in our society.
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Melanoma , Neoplasias Cutáneas , Adulto , Antineoplásicos/uso terapéutico , Biopsia , Vacunas contra el Cáncer/uso terapéutico , Quimioterapia Adyuvante , Terapia Combinada , Femenino , Humanos , Factores Inmunológicos/uso terapéutico , Inmunoterapia , Metástasis Linfática , Masculino , Melanoma/diagnóstico , Melanoma/patología , Melanoma/secundario , Melanoma/terapia , Persona de Mediana Edad , Estadificación de Neoplasias , Cuidados Paliativos , Manejo de Atención al Paciente , Examen Físico , Radioterapia Adyuvante , Sistema de Registros , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/terapiaRESUMEN
Imiquimod is an immunomodifier recently approved for the treatment of superficial basal cell carcinomas (sBCC). Although local adverse events (AEs) are the most commonly reported, systemic AEs have also been described. We present the case of a 60-year-old woman who, after the application of two sachets of imiquimod cream per day for 5 days/week to two large sBCCs, developed pemphigus-like lesions both at and distant from the application site. Histological examination of a skin biopsy found intraepidermal acantholytic blistering but results of direct immunofluorescence examination were negative. The lesions resolved after cessation of imiquimod. Two previous cases of imiquimod-induced pemphigus have been reported, but this is the first case with lesions distant from the site of application. We suggest that systemic absorption of the drug or greatly increased synthesis of cytokines could explain this reaction and recommend the use of low doses of imiquimod in the treatment of large or multiple sBCCs.
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Aminoquinolinas/efectos adversos , Antineoplásicos/efectos adversos , Erupciones por Medicamentos/etiología , Pénfigo/etiología , Carcinoma Basocelular/tratamiento farmacológico , Erupciones por Medicamentos/patología , Femenino , Humanos , Imiquimod , Persona de Mediana Edad , Pénfigo/patología , Neoplasias Cutáneas/tratamiento farmacológicoRESUMEN
This review is devoted to analytical methods published in the scientific literature in the last 10 years for the determination of emerging contaminants in aquatic media. The article is mainly focused on sample preparation and on instrumental techniques most used for the detection and quantification of the analytes of interest. The sample preparation techniques include classical liquid-liquid extraction and solid-phase extraction, but also recent microextraction techniques such as solid-phase microextraction, stir-bar sorptive extraction, dispersive liquid-liquid microextraction, ultrasound-assisted emulsification microextraction, or microextraction by packed sorbent. Most studies focus on minimizing the number of analysis steps and on the use of the lowest amount of solvents in the sample treatment step. Liquid chromatography and gas chromatography mainly coupled to tandem mass spectrometry are usually the employed analytical techniques. A large number of multiresidue methods are being developed for the determination of several families of these compounds with only one extraction step to minimize sample handling and treatment.
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Cromatografía/métodos , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Agua/químicaRESUMEN
OBJECTIVE: To determine the reliability of the interpretation of electrocardiograms (ECG) by general practitioners and those in training by making a comparison with the interpretation made by the cardiologist. MATERIAL AND METHODS: An observational study was conducted that included general practitioners working in the Toledo Health Area, physicians during their training in Family and Community Medicine, and cardiologists in their first 3 years of specialist training (R1-R3). A questionnaire was used that included 13 ECGs with no clinical details of the patient. The 13 ECGs were selected and their diagnoses made by consensus by 2 cardiologists from the Toledo Hospital Complex. RESULTS: The highest percentage of correct answers (82.3%) was obtained for ECG 5 (atrial fibrillation), and the lowest (26.5%) for ECG 11 (junctional rhythm). The highest diagnostic skill was achieved by the resident cardiologists, general practitioners, medical tutors, and doctors who had worked in hospital emergency departments. The highest odds ratio for a higher diagnostic skill was to work in an emergency department and be a practising general practitioner, both with almost significant results (P<.10). CONCLUSIONS: Family physicians and those in training have a medium level of reliability in the interpretation of an ECG compared to the cardiologist.
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Competencia Clínica , Electrocardiografía/métodos , Médicos Generales/normas , Estudiantes de Medicina , Adulto , Enfermedades Cardiovasculares/diagnóstico , Femenino , Humanos , Internado y Residencia , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , España , Adulto JovenRESUMEN
Time-to-positivity is useful in the diagnosis of catheter-related bacteraemia and as a predictor of an endovascular source in patients with Staphylococcus aureus bacteraemia. However, this parameter has been evaluated for only a limited number of microorganisms. In the present study, time-to-positivity was recorded for 1872 episodes of significant monomicrobial bacteraemia diagnosed at a teaching hospital during a 2-year period, and the associated microbial and clinical variables were investigated. According to multivariate analysis, Streptococcus pneumoniae, beta-haemolytic streptococci, Escherichia coli, Klebsiella, Enterobacter, Citrobacter and Aeromonas were characterised by fast growth, with an endovascular source, shock, liver cirrhosis and neutropenia also predicting a short time-to-positivity. For patients not receiving appropriate antibiotics, detection of Gram-positive cocci in clusters within 14 h was predictive of Staph. aureus; a time-to-positivity of >21 h ruled out the possibility that a Gram-positive organism in chains was a beta-haemolytic streptococcus or Strep. pneumoniae, and a time-to-positivity of < or =12 h meant that it was very unlikely that a Gram-negative bacillus was a non-fermenter. A time-to-positivity of < or =8 h was predictive of a non-urinary tract source in patients with E. coli bacteraemia, and detection of growth within 13 h predicted an endovascular source in those with Staph. aureus bacteraemia. In conclusion, time-to-positivity depended on the microorganism, original source and clinical variables involved. Although this measurement may provide some early clues concerning the microorganisms involved and the source of bacteraemia, its clinical impact remains to be defined.