The outcome assessors were not advised of subject group assignment and only had access to the study ID number associated with a given video recording. They were also unaware of other data collected as part of the trial. Collected data was input by GH, with verification by MP. The research assistants conducting the trial were conceivably aware of the purpose of Inhibitors,research,lifescience,medical the trial (though had no conflicts of interest with respect to the study outcomes). All investigators had access to the raw data. We therefore considered our trial as single-blind. The model The model in this study is best described as a low fidelity simulator rendered “physiologic” in

that it incorporated a 1.00-inch, 22-gauge IV catheter. Catheters of this size are used clinically in newborn to adolescent age patients, making this a rational choice for our purposes. Inhibitors,research,lifescience,medical Please see Additional file 1 for figures of the model and a detailed description. Intervention procedure Following written consent, participants were randomized to one of the four syringe size groups (10, 20, 30, or 60 mL). Upon receiving the participant group assignment, a research assistant Inhibitors,research,lifescience,medical measured 900 mL of 0.9% normal

saline using a graduated cylinder and then this was divided into three 300 mL aliquots (each aliquot 20 mL/kg based on a 15 kg simulated patient). Each aliquot was then drawn up into colour-coded syringes of the assigned size, with each of the three aliquots having a unique assigned colour. Syringes of the same colour were then placed in each of three kidney bowls. To ensure adequate familiarity with study procedures and the model prior to formal testing, all else Subjects underwent a standardization procedure [11]. Inhibitors,research,lifescience,medical This consisted of a brief video orienting participants to the study Inhibitors,research,lifescience,medical setting and demonstrating the ‘disconnect-reconnect’

technique. Subjects were then provided with 3 fluid-filled demonstration syringes and given a brief opportunity to practice the technique. Following this, subjects were verbally presented with a clinical vignette of a febrile 15 kg toddler in decompensated septic shock in need of immediate rapid fluid resuscitation. They were advised to administer the fluid using the provided syringes as rapidly as possible, finishing each 20 mL/kg colour set in sequence. Trials were commenced on verbal prompt by the research assistant and proceeded Brefeldin_A without interruption. All subject testing was video recorded in a manner which captured the manual performance of fluid administration for outcome ascertainment purposes, but which did not capture participant identifiers. In addition to video recording all testing, the research assistant timed with a stopwatch the initial two participant trials. Due to clear inaccuracies with use of the stopwatch timing method, we reverted to use of the trial video recordings for outcome ascertainment as per our a priori plan.