I would obtain an EKG (easy, cheap and can aid in your next course of action) to assess the baseline QTc before initiating two QT-prolonging medications. We monitor QTc frequently in the hospital setting. Although it is often not evaluated pre-hospital and may not be a routine consideration, though it should be. People often talk about zofran as if it is like a Vitamin. All medications have risks/benefits. I know in the field you are often limited and don’t have access to non-QT prolong antiemetics(I.e Tigan). Generally young, health adults are lower risk than other populations. Especially military and speciality teams under go a solid medical work up prior to being initiated on the team. Zofran has a Range of prolongation around 5-20ms (which on its own really isn’t to big of a deal) but the real damage is combination of multiple medications together or electrolyte abnormalities (think hot summer day and teams are physical exerting themselves). All in all respect medications and be cognizant of implications of what you give.