The goal of this prospective clinical study is to evaluate the effect of different High Flow Nasal Cannula (HFNC) flow rates on diaphragm, rectoabdominal, and oblique thickening fraction, and to determine whether this effect depends on the action of HFNC flow rates on Functional Residual Capacity (FRC) in Infants under 2 years of age with a diagnosis of bronchiolitis and indication for use of HFNC. The main question\[s\] it aims to answer are: * If the thickening fraction of the abdominal muscle and diaphragm will change at the different flow rates evaluated * If the end-expiration lung impedance (EELZ) will change at the different flow rates evaluated The belt will be installed around the chest before the start of the change in flow rates and monitoring with Electrical Impedance Tomography (EIT) will be initiated. Patients will be positioned in dorsal decubitus elevated 10 to 20 degrees and monitoring will be performed continuously during all flow rate variations and also during the ultrasound performance. Four different randomized flow rates will be used for evaluation: 2.0 liter.Kg-1.min-1, 1.5 liter.Kg-1.min-1, 1.0 liter.Kg-1.min-1, 0.5 liter.Kg-1.min-1. At the end of the randomized order evaluation the infant will remain in the flow of 0.5 liter.Kg-1.min-1 for 5 minutes and then return to the flow of 2.0 liter.Kg-1.min-1. The EIT parameters, ultrasound assessment, and clinical variables will be collected at the end of the 5-minute stay in each lane. The randomization of the order of application of the phases will be carried out in blocks, so that the homogeneity of the sequences is maintained even if the collection is interrupted before reaching the total number of individuals. The blocks will be of size two and four and the test and production lists will be generated with the help of the R packages.