Ondansetron oral dissolving tablets are superior to normal saline alone for prehospital nausea

Antiemetics have been shown to be effective in multiple hospital settings, but few studies have been done in the prehospital environment.

Our hypotheses were 1) that the amount of normal saline administered during an emergency medical services (EMS) transport was not related to a change in nausea and vomiting and 2) that the addition of the ondansetron orally disintegrating tablet (ODT) would decrease the degree of nausea.

This was a pre-post study of two cohorts of consecutive patients with nausea in the prehospital setting. During phase 1 of the study, our local EMS agency adopted a protocol form to complete whenever a patient with nausea and/or vomiting was assessed and transported to one of the area hospitals. Patients were asked to rate their nausea on a visual analog scale (VAS) and a Likert scale, and saline administration and active vomiting were documented. During phase 2, our EMS system adopted the use of ondansetron ODT for nausea and continued to complete the same forms. The nausea forms completed by EMS during phase 1 (saline only) and phase 2 (ondansetron ODT) were evaluated and compared. For both phases, the primary outcome measures were the change in VAS nausea rating (0 = no nausea, 100 = most nausea imaginable) from beginning to end of the transport and the results on the Likert scale completed at the end of the transport. Relationships were considered significant if p < 0.01.

Data were collected from 274 transports in phase 1 and 372 transports in phase 2. The average patient age was 50 ± 12 years. In phase 1 of the study, 178 of 274 patients (65%) received normal saline (mean volume ± standard deviation = 265 ± 192 mL). There was no significant correlation between the VAS change and the amount of fluid administration in either phase of the study. Conversely, during phase 2, patients receiving ondansetron ODT showed significant improvement in both measures of nausea. The difference in nausea improvement between phase 1 and phase 2 was significant (difference in VAS change: 24.6; 95% confidence interval 20.9, 28.3).

There was no improvement in patient nausea related to quantity of saline alone during an EMS transport. The addition of ondansetron ODT resulted in a significant improvement in degree of nausea.