Introduccion: la mascara laringea es un sistema para el manejo de la via aerea, que puede colocarse con escasa manipulacion del cuello y sin necesidad de introducir dedos en la cavidad oral. OBJETIVO: comparar la incidencia de laringoespasmo, saturacion de oxigeno <90% y tos, en anestesia con mascara laringea en ninos, teniendo en cuenta tres diferentes formas de lubricacion. METODOLOGIA: se realizo ensayo clinico, se aleatorizaron los pacientes en tres grupos, de acuerdo el metodo de lubricacion de la mascara laringea previo a su insercion. En el grupo A, se aplico lidocaina gel al 2% en la parte anterior de la mascara. En el grupo B, lidocaina gel al 2% en la parte posterior. En el grupo C se lubricaron ambas caras con solucion salina. Los datos fueron analizados con Epi-Info (TM) 3.5.3. Se utilizaron las pruebas ANOVA y Chi–cuadrado. La significancia estadistica fue determinada por p< 0.05. RESULTADOS: se incluyeron 102 ninos, que fueron distribuidos equitativamente en los tres grupos de lubricacion. La presencia de eventos fue: respiratorios totales 20.6%, Tos 18.6%, SO2 < 90%7.8% y laringoespasmo 5.9%. La distribucion de caracteristicas clinicas, factores de riesgo y medicamentos no tuvo diferencias estadisticamente significativas en los tres grupos del estudio. Se encontraron diferencias significativas en los siguientes aspectos: el grupo de lubricacion con solucion salina tuvo menor incidencia de tos en comparacion con los otros grupos, menor presencia de perdida de la saturacion en el grupo de solucion salina cuando se comparo con la agrupacion de los dos grupos lubricados con lidocaina y disminucion del numero de eventos respiratorios totales en el grupo de solucion salina. En los pacientes en quienes se retiro la mascara laringea en un plano anestesico profundo, tuvieron menor presencia de tos, los que tenian mascara lubricada con solucion salina frente a los que la tenian con lidocaina en la cara anterior. No se encontraron diferencias significativas en ocurrencia de laringoespasmo al comparar los tres grupos. Ninguno de los pacientes presento bradicardia, paro cardiaco ni edema pulmonar. CONCLUSIONES: se demostro menor incidencia de eventos respiratorios, tos y perdida de la saturacion de oxigeno en el grupo con mascaras laringeas lubricada con solucion salina en ambas caras. Rev.cienc.biomed. 2013;4(1)75-85 PALABRAS CLAVES Lidocaina; Mascaras laringeas; Tos; Anestesia; Nino. SUMMARY Introduction: Laryngeal mask is a system for the airway management that can be placed with limited handing of the neck and without the need to introduce fingers in the mouth. Objective: Compare the incidence of laryngospasm, oxygen saturation < 90% and cough in anesthesia with laryngeal mask in children, keeping in mind three different ways of lubrication. Methods: Clinical trial was carried out. Patients were randomized to three groups according to the method of lubrication of the laryngeal mask prior to the insertion. In the A group, in the previous part of the mask was applied lidocaine 2% gel and in the B group lidocaine 2% gel was applied in the preceding part. In the C group both sides were lubricated with saline solution. Data analysis was performed using Epi-Info (TM) 3.5.3 program. Chi-square and Analysis of Variance (ANOVA) were used. The statistical significance was determined by p < 0.05. Results: 102 children were included; they were distributed equitably in the three groups of lubrication. The presence of events was: total respiratory events 20.6%, cough 18.6%, SO2 < 90% 7.8% and laryngospasm 5.9%. The distribution of clinical characteristics, risk factors and medication did not have statistically significant differences in the three groups of study. There were statistically significant differences in the following aspects: The group of lubrication with saline solution had lower incidence of cough than the other groups and had lower presence of oxygen desaturation and reduction of the number of total respiratory events when it was compared with both groups lubricated with lidocaine. Those patients in which the laryngeal mask was moved away with deep anesthesia had lower presence of cough than those with mask lubricated with saline solution in front of those with lidocaine in the previous part of the mask. There were not found significant differences in the occurrence of laryngospasm when the three groups where compared. None of the patients had bradycardia, heart arrest or pulmonary edema. Conclusions: There was demonstrated lower incidence of respiratory events, cough and loss of oxygen saturation in the group with laryngeal masks lubricated with saline solution in both sides . Rev.cienc.biomed. 2013;4(1)75-85 KEYWORDS Lidocaine; Laryngeal Masks; Cough; Anesthesia; Child.