RESUMEN
BACKGROUND: The incidence of anesthesia-induced atelectasis in children is high and closely related to episodes of hypoxemia. The Air-Test is a simple maneuver to detect lung collapse. By a step-reduction in FiO
Asunto(s)
Atelectasia Pulmonar , Humanos , Atelectasia Pulmonar/diagnóstico por imagen , Atelectasia Pulmonar/diagnóstico , Preescolar , Niño , Femenino , Masculino , Lactante , Estudios Retrospectivos , Adolescente , Estudios Prospectivos , UltrasonografíaRESUMEN
OBJECTIVE: For diagnostic tests, the most common graphical representation of the information is the receiver-operating characteristic (ROC) curve. The "agreement chart" displays the information of two observers independently classifying the same n items into the same k categories, and can be used if one considers one of the "observers" as the diagnostic test and the other as the known outcome. This study compares the two charts and their ability to visually portray the various relevant summary statistics that assess how good a diagnostic test may be, such as sensitivity, specificity, predictive values, and likelihood ratios. STUDY DESIGN AND SETTING: The geometric relationships displayed in the charts are first described. The relationship between the two graphical representations and various summary statistics is illustrated using data from three common epidemiologically relevant health issues: coronary heart disease, screening for breast cancer, and screening for tuberculosis. RESULTS: Whereas the ROC curve incorporates information on sensitivity and specificity, the agreement chart includes information on the positive and negative predictive values of the diagnostic test. CONCLUSION: The agreement chart should be considered as an alternative visual representation to the ROC for diagnostic tests.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Enfermedad Coronaria/diagnóstico , Pruebas Diagnósticas de Rutina/métodos , Curva ROC , Tuberculosis/diagnóstico , Área Bajo la Curva , Neoplasias de la Mama/epidemiología , Enfermedad Coronaria/epidemiología , Reacciones Falso Positivas , Femenino , Humanos , Tamizaje Masivo , Modelos Estadísticos , Variaciones Dependientes del Observador , Sensibilidad y Especificidad , Tuberculosis/epidemiologíaRESUMEN
OBJECTIVE: To determine the utility of biochemical parameters such as lactic acid (LA), C-reactive protein (CRP), microalbuminuria (MAU), and base deficit (BD) as early markers of complications in the immediate postoperative evolution of elective open gastrointestinal surgeries. DESIGN AND METHODS: Sixty-two patients subject to elective open gastrointestinal surgery were evaluated during a period of 22 months. RESULTS: From the initial 62 patients, 2 were excluded, 29 (48.3%) evolved without complications, and 31 (51.6%) with complications. It was observed that the most significant areas under the ROC curve corresponded to BD in the preoperative period, LA on the first day, and CRP from the second to the seventh day after surgery. MAU was not a discriminating parameter since it did not reach a significant area under the curve (AUC) at any time. CONCLUSIONS: The biochemical markers that best relate to the presence of complications are BD in the preoperative period, LA on the first day, and CRP from the second to the seventh day after surgery.