Zofran is kinda bullshit.
It was originally only used for nausea secondary to chemotherapy, and for that, it is great. At some point people higher up the chain from us mere mortals decided that it was relatively benign, and could therefore be given for ALL the nauseas.
It’d be like expecting narcan to reverse a benzodiazepine overdose. Similar presentation, very different cause.
This being /r/EMS, I want to head off at the pass the “ACKTSHUALLY...” crowd. Zofran is relatively benign. Full stop.
The qt prolongation only really becomes a consideration when either A. You’re giving significantly more than any reasonable prehospital protocol would allow(if my memory serves it starts being an issue around 40mg) or B. The pt is taking another qt prolonging medication e.g. methadone.