RESUMEN
A 41-year-old man was admitted to the Emergency Department with bilateral numbness in lower extremities and left femoral palsy. He also reported constitutional symptoms, vomiting and non-bloody diarrhoea for the last several months. He had a previous history of eosinophilic asthma with erratic follow-up. During admission, eosinophil count was 66% of white blood cells. Sural nerve biopsy revealed vasculitis with eosinophilic infiltration. Further evaluations consisted of colonoscopy and nasal endoscopy that confirmed eosinophil infiltrates on colonic ulcers and nasal polypi. The patient was started on systemic corticosteroids and cyclophosphamide. Among his personal records, he had been taking nandrolone decanoate without medical prescription, and had withdrawn a few years before the first asthma exacerbation.
RESUMEN
Many physiological systems are paradigmatic examples of complex networks, displaying behaviors best studied by means of tools derived from nonlinear dynamics and fractal geometry. Furthermore, while conventional wisdom considers health as an 'orderly' situation (and diseases are often called 'disorders'), truth is that health is characterized by a remarkable (pseudo)-randomness, and the loss of this pseudo-randomness (i.e., the 'decomplex-ification' of the system's output) is one of the earliest signs of the system's dysfunction. The potential clinical uses of this information are evident. However, the instruments used to assess complexity are still under debate, and these tools are just beginning to find their place at the bedside. We present a brief overview of the potential uses of complexity analysis in several areas of clinical medicine. We comment on the metrics most frequently used, and we review specifically their application on certain neurologic diseases, aging, diabetes, febrile diseases and the critically ill patient.
Asunto(s)
Envejecimiento/fisiología , Diabetes Mellitus/fisiopatología , Entropía , Fiebre/fisiopatología , Enfermedades del Sistema Nervioso/fisiopatología , Dinámicas no Lineales , Enfermedad Crítica , Fractales , HumanosRESUMEN
OBJECTIVE: We study the extent to which procalcitonin (Pro-CT) and/or C-reactive protein (CRP) may be helpful in the early triage of febrile patients admitted to a general internal medicine ward. METHODS: This is a prospective, observational study on 62 admitted patients in whom a temperature >38°C had been observed the day before inclusion. RESULTS: Neither Pro-CT nor CRP was able to discriminate infectious (or bacterial) diseases from the other etiologies as a group, with an area under the ROC curve of 0.63 (95% CI 0.47-0.79, p=0.15) for Pro-CT and 0.61, (95CI 0.44-0.78, p=0.23) for CRP. Sensitivity and specificity for Pro-CT varied between 0.59 and 0.67 for a cut-off point of 0.2 ng/mL and 0.03 and 1 for a cut-off point of 10.0 ng/mL. However, in subgroup analysis, Pro-CT was able to discriminate between infectious and inflammatory diseases (Welch two sample t-test t=2.39, df=44.3, p=0.021).
Asunto(s)
Proteína C-Reactiva/biosíntesis , Calcitonina/sangre , Fiebre/sangre , Precursores de Proteínas/sangre , Anciano , Biomarcadores/metabolismo , Péptido Relacionado con Gen de Calcitonina , Hospitalización , Humanos , Inflamación , Pacientes Internos , Medicina Interna/métodos , Persona de Mediana Edad , Estudios Prospectivos , Curva ROC , Sensibilidad y Especificidad , TemperaturaRESUMEN
The classic anatomo-clinic paradigm based on clinical syndromes is fraught with problems. Nevertheless, for multiple reasons, clinicians are reluctant to embrace a more pathophysiological approach, even though this is the prevalent paradigm under "which basic sciences work. In recent decades, nonlinear dynamics ("chaos theory") and fractal geometry have provided powerful new tools to analyze physiological systems. However, these tools are embedded in the pathophysiological perspective and are not easily translated to our classic syndromes. This article comments on the problems raised by the conventional anatomo-clinic paradigm and reviews three areas in which the influence of nonlinear dynamics and fractal geometry can be especially prominent: disease as a loss of complexity, the idea of homeostasis, and fractals in pathology.