[Clinician and researcher at the time. Is it possible?] / Clínico e investigador a la vez, ¿se puede?

Research in clinical practice arises as a constant need for improvement to provide better care to patients, train better human resources and make a daily reflection on the amount of scientific information we receive every day. We want to reflect on how the Centro de Adiestramiento en Investigación Clínica (CAIC) from our healthcare activity changed our practice.

La investigación en la práctica clínica surge como una necesidad constante de mejora, a fin de dar una atención de mayor calidad a los pacientes, formar recursos humanos más preparados y hacer una reflexión diaria ante la cantidad de información científica que recibimos todos los días. Queremos hacer una reflexión de como el Centro de Adiestramiento en Investigación Clínica (CAIC) desde nuestra actividad asistencial cambió nuestra práctica.

Prognostic impact of the preoperatory neutrophil/lymphocyte index on early surgical complications of patients with colorectal cancer.

Colorectal cancer (CRC) is found among those with greatest frequency and exponential increase worldwide, with high mortality rates, which are observed as increasing due to the postsurgical complications that come to present. Systemic inflammation participates in the development and progression of cancer; therefore, inflammatory and/or immunological response markers such as the neutrophil/lymphocyte index (NLI) can aid us in predicting the poor results of our interventions. The purpose of our study was to determine the impact of an NLI of ≥2.6 as a predictor of early postsurgical complications. By means of a prospective cohort, we analyzed 158 patients with CRC who were submitted to elective surgery with a later 30-day follow-up. We found that the preoperatory NLI of ≥2.6 obtained an odds ratio (OR) = 2.24 (95% confidence interval [CI], 1.15-4.36) as a prognostic factor of early postsurgical complications according to the Clavien-Dindo classification scale, which represents a low prognostic impact due to its predictive yield with low accuracy, which is the opposite of what other reports have previously published. The use of chemotherapy before the surgical procedure was also determined to be a risk factor for post-surgical complications.

[List of Ethical Principles for Medical Research Involving Human Subjects]. / Lista para Aspectos Éticos de Investigaciones en Humanos.

The ethical principles of a research proposal are not contained only in a paragraph or in the informed consent form; actually, they are an essential part of the whole protocol from the beginning to the end. In a complementary manner to the regulatory and educative documents, our objective in this article is to propose a checklist of questions so researches can ensure they have included the necessary information and precautions to meet the ethical considerations that are required for every research with human beings, which shall be called List of Ethical Principles for Medical Research Involving Human Subjects. We propose questions that researchers must ask themselves when they compose the background, justification, objectives, research question, hypothesis, selection criteria, sample size calculation, sampling, research design, statistical analysis plan, ethical aspects, publication plan, and references.

Los aspectos éticos de una propuesta de investigación no están contenidos solamente en un apartado y en el formulario de consentimiento informado, en realidad forman parte esencial de todo el protocolo desde el inicio hasta el final. De manera complementaria a los documentos regulatorios y educativos, el objetivo en este artículo es proponer una lista de cotejo de preguntas para que el investigador pueda asegurarse de haber incluido la información y elementos necesarios para cumplir con los aspectos éticos que toda investigación con seres humanos demanda, a la cual llamaremos LAEIH (Lista para Aspectos Éticos de Investigaciones en Humanos). Proponemos preguntas que deben hacerse los investigadores al redactar los antecedentes, la justificación, objetivos, pregunta de investigación, hipótesis, criterios se selección, cálculo de tamaño de muestra, muestreo, diseño de investigación, plan de análisis estadístico, aspectos éticos, plan de publicación y referencias.

[Clinical research XX. From clinical judgment to multiple logistic regression model]. / Investigación clínica XX. Del juicio clínico a la regresión logística múltiple.

The complexity of the causality phenomenon in clinical practice implies that the result of a maneuver is not solely caused by the maneuver, but by the interaction among the maneuver and other baseline factors or variables occurring during the maneuver. This requires methodological designs that allow the evaluation of these variables. When the outcome is a binary variable, we use the multiple logistic regression model (MLRM). This multivariate model is useful when we want to predict or explain, adjusting due to the effect of several risk factors, the effect of a maneuver or exposition over the outcome. In order to perform an MLRM, the outcome or dependent variable must be a binary variable and both categories must mutually exclude each other (i.e. live/death, healthy/ill); on the other hand, independent variables or risk factors may be either qualitative or quantitative. The effect measure obtained from this model is the odds ratio (OR) with 95 % confidence intervals (CI), from which we can estimate the proportion of the outcome's variability explained through the risk factors. For these reasons, the MLRM is used in clinical research, since one of the main objectives in clinical practice comprises the ability to predict or explain an event where different risk or prognostic factors are taken into account.

La complejidad del fenómeno de causalidad en la práctica clínica implica que el resultado de una maniobra no se deba únicamente a esta, sino a la interacción con otros factores del estado basal o variables que ocurran durante la maniobra. Esto requiere diseños metodológicos que permitan evaluar estas variables. Cuando el resultado es dicotómico, se usa la regresión logística múltiple (RLM). La RLM es un modelo multivariado útil cuando se requiere predecir o explicar, al ajustar por el efecto de distintos factores de riesgo, el efecto de una maniobra o exposición sobre el desenlace. Para realizar la RLM se requiere que el desenlace (o la variable dependiente) sea dicotómico y mutuamente excluyente (por ejemplo, vivo/muerto, enfermo/sano); las variables independientes o factores de riesgo pueden ser cuantitativas o cualitativas. La asociación que se obtiene es la razón de probabilidades, también llamada razón de momios (RM), con intervalos de confianza (IC) del 95 % y con estas medidas se estima el porcentaje de la variabilidad del desenlace que se explica a partir de los factores de riesgo. Por estas razones, este modelo es el más usado en la investigación clínica, ya que uno de los principales objetivos de la práctica clínica es poder predecir o explicar un evento en el que se tomen en cuenta diferentes factores de riesgo.

Risk factors for subclavian vein thrombosis in cancer patients with total parenteral nutrition.

BACKGROUND: There are few reports on total parenteral nutrition (TPN) and its possible prothrombotic effect. The purpose of this study was to identify risk factors for subclavian vein thrombosis (SVT) in patients receiving TPN. METHOD: Cancer patients with indwelling subclavian catheters and TPN were followed in a cohort study. Doppler ultrasound examination was performed 8 and 30 days after catheter placement. RESULTS: One hundred twenty-one patients were included, with a mean of 61 (± 11.8) years of age. We detected 36 SVT events at day 8 (29.8%) and 47 (38.8%) at day 30 after central catheter placement. Mean length of subclavian catheterization was 17.2 (± 8.2) days. Fifty-three point three percent of patients receiving ≥ 3,050 mOsm TPN in 24 hours developed SVT (relative risk (RR) = 2.01, 95% CI, 1.14 - 3.57; P = 0.016) at day 8 and 60% (RR = 1.67, 95% CI, 1.30 - 2.71; P = 0.038) at day 30 post-catheter placement. Protein administration of > 97.5 g/day was shown to be a risk factor for early thrombosis with a mean of 16.88 days for the development of SVT (95% CI, 10 - 23.7) versus 27.8 days (95% CI, 25.8 - 29.9) in the group with nutritional protein content < 97.5 g/day (P = 0.000). CONCLUSION: High-osmolarity and high-protein nutrition formulas were shown to be risk factors for SVT in cancer patients receiving TPN.