Manage airway risk, assess perfusion, and use the adult or pediatric antiemetic pathway.
OCEMS source summary · Updated 2026-09-16
Key cautions & base contact
Adult ondansetron orders exclude known or suspected pregnancy.
Use the pediatric age restriction and fluid maximums explicitly; do not scale the adult ODT regimen by weight.
Assess before treating symptoms
Evaluate airway protection, vomiting, perfusion, and signs of dehydration. Keep suction available and maintain the airway.
An altered level of consciousness or severe poor perfusion should prompt the applicable broader condition order rather than an antiemetic-only approach.
Adult / adolescent
For dehydration or poor perfusion with clear lungs/no CHF, give 250 mL saline boluses up to 1 L as needed for perfusion.
For continued nausea/vomiting when pregnancy is not known or suspected: ondansetron 8 mg ODT, or 4 mg IV. The IV dose may repeat once after about 3 minutes for continued/recurrent symptoms.
Transport to an appropriate ERC, with ALS escort when medication or fluids were needed.
Pediatric — SO-P-090
For dehydration/poor perfusion, give 20 mL/kg saline IV/IO, maximum 250 mL per bolus, and contact base (pediatric-capable preferred). May repeat twice for 3 total boluses.
Age 4 and older: one 4 mg ondansetron ODT as tolerated. The source does not give an ODT regimen below age 4 or routine pediatric IV ondansetron.
If altered/unresponsive, check glucose and follow the source’s hypoglycemia treatment, including the limited IO dextrose exception.
Reassess & handoff
Reassess airway protection, vomiting frequency, mental status, vital signs, and response to fluid or medication. Document dose times and total fluid.
Pediatric vomiting can accompany diabetic ketoacidosis with marked hyperglycemia; assess the underlying cause and perfusion, not just symptom relief.