As this is a crossover trial, the study arms denote the order in which the two interventions are performed by the subject. In Arm A, subjects will perform the "Push-Pull Technique" of manual fluid resuscitation first, followed by the "Disconnect-Reconnect Technique" second. A washout period of at least 30 minutes between each of the two interventions will be observed.

As this is a crossover trial, the study arms denote the order in which the two interventions are performed by the subject. In Arm B, subjects will perform the "Disconnect-Reconnect Technique" of manual fluid resuscitation first, followed by the "Push-Pull Technique" second. A washout period of at least 30 minutes between each of the two interventions will be observed.

Participants will administer 900 mL (60 mL/kg) of NS to a model of a 15 kg toddler in shock. The intervention is the mode of administration of the fluid. For the "Push-Pull Technique", the 7 cm catheter extension tubing will be connected to one of the three ports of a triple stopcock. A second of the 3 ports of the triple stopcock will be connected to an IV tubing set connected to a 1 L bag of NS. A 60 mL syringe will be connected to the third port of the triple stopcock. On verbal prompt, participants will "pull" fluid from the bag of NS by withdrawing the plunger of the 60 mL syringe, filling it with saline. They will then toggle the switch of the triple stopcock, so that it is "off" to the bag of NS and "open" to IV catheter extension tubing leading to the model. They will then depress the syringe plunger, administering the fluid to the model. These steps will be repeated until each participant believes that they have administered the requested volume of fluid to the model.

Start Intervention Time is defined as the time that the model begins to effectively receive normal saline as administered by the participant, determined by the time at which fluid begins to collect in the graduated cylinder. End Intervention Time is defined as the time at which the model ceases to effectively receive further normal saline as determined by the time at which fluid stops collecting in the graduated cylinder. All testing will be videorecorded, with video reviews conducted by two independent and blinded outcome assessors using strict criteria to determine total intervention time (Total intervention time = end intervention time - start intervention time). At the time of subject testing, the research assistant will also record the total amount of normal saline collected in the graduated cylinder at the end of the intervention. Total intervention rate (mL/s) = volume of normal saline collected/Total intervention time.

Total volume of normal saline (mL) effectively administered to the model by the participant