Is it time to say good bye to blow-by?

While it has been clearly demonstrated that spontaneously breathing children of all ages with bronchospasm respond well to nebulized bronchodilators, only a small proportion of aerosolized drug reaches the lungs. 1–9 In addition, the combination of a small airway diameter, a rapid breathing pattern, and poor tolerance to the treatment has made delivery of nebulized medications to the airway of pediatric patients very challenging. The face mask is one of the most frequently prescribed aerosol devices for the administration of bronchodilators to children, in a variety of clinical settings. Their advantage is the little to no cooperation required from the child. Nevertheless, the presence of a tight seal on the patient's face has been considered a critical element to improve aerosol delivery. Amirav et al have found that the absence of this seal between the mask and the patient's face results in a decrease in the amount of medication available for inhalation. 10 Children, especially those who are combative and crying, often resist or reject the presence of an aerosol mask on their faces; thus, the efficacy of aerosol therapy administered to agitated children may be negligible. 11 In order to avoid the poor tolerance children have to the tightly applied aerosol mask, clinicians often place the mask away from the child's face, a technique also known as " blow by. " However, experimental data have revealed that the greater the distance between the aerosol mask and the patient's face, the lower the amount of inhaled drug mass. 2,12 After conducting an evaluation of 3 different mask designs at 3 different distances from a mannequin face, we reported that mask design affected nebulized al-buterol delivery and that inhaled drug mass was significantly reduced as the aerosol mask was moved away from the face. 12 We had also previously reported that nebulized albu-terol delivery, measured as inhaled drug mass, was significantly reduced as the aerosol mask or T-piece 13 was moved away from the face 12 in a pediatric lung model of spontaneous breathing. An accompanying editorial titled " Bye-Bye, Blow-By " called for a recommendation to discourage clinicians from using the blow-by technique, based on available data. 14 To address some of the challenges encountered during the administration of nebulized medications to spontaneously breathing children, research has focused on several areas. These include the evaluation of newer interfaces and different types of aerosol systems, and the impact of administering the …