Do not give if pt's systolic is close to 100. If b/p falls below but pt in trendelenberg; pt has head injury; pt is infant or child; pt has taken max dosage; pt has taken ED meds
Why 100 systolic? Are there times when it is below that it would be ok to? Who picked that number?
The legendary Trendelenberg, might not have the effet you want. (or any at all)
Max dosage 3? I hope your transport time is less than 9-15 minutes.