Nausea is a common symptom among patients presenting to the emergency department and can negatively affect patient comfort and clinical outcomes. The timing of antiemetic administration may play a critical role in symptom control; however, evidence regarding the optimal timing remains limited. This multicenter interventional study aims to evaluate the effect of early versus delayed antiemetic administration on nausea severity and patient comfort in adult emergency department patients. Participants will be assigned to receive antiemetic treatment either within the first 30 minutes after triage or after 30 minutes. Nausea severity will be assessed using a numeric rating scale, and patient comfort will be evaluated at predefined time points. The findings of this study are expected to contribute to improving symptom management and optimizing clinical practices in emergency care settings.

Nausea is a frequently encountered symptom in emergency department (ED) patients and is associated with decreased patient comfort, prolonged ED stay, and reduced satisfaction with care. Timely management of nausea is essential for improving patient outcomes; however, there is limited evidence regarding the impact of antiemetic administration timing on symptom relief and patient comfort. This study is designed as a prospective, multicenter interventional study to evaluate the effect of antiemetic timing on nausea severity and patient comfort in adult ED patients.

Eligible participants will include adult patients presenting to the ED with nausea. Participants will be allocated into two groups based on the timing of antiemetic administration: early administration (within 30 minutes after triage) and delayed administration (after 30 minutes). Antiemetic agents will be administered according to standard clinical practice.

The primary outcome of the study is nausea severity, which will be measured using a validated numeric rating scale. Secondary outcomes include patient comfort levels and changes in nausea over time. Measurements will be obtained at baseline and at predefined time intervals following antiemetic administration.

This study aims to provide evidence on whether early administration of antiemetic therapy leads to improved symptom control and patient comfort compared to delayed administration. The results may inform clinical decision-making and contribute to the development of evidence-based protocols for nausea management in emergency settings.

Inclusion Criteria:

• Age ≥18 years
• Presentation to the emergency department with nausea (with or without vomiting)
• Receiving antiemetic treatment
• Ability to communicate
• Ability to provide informed consent
• Ability to undergo nausea assessment using a Numeric Rating Scale (NRS) at initial evaluation

Exclusion Criteria:

• Altered level of consciousness (unconscious or confused)
• Intubated patients
• Severe psychiatric conditions (e.g., psychosis or delirium)
• Patients in critical condition requiring immediate resuscitation
• Hemodynamic instability
• Inability to communicate (including language barrier or severe hearing/speech impairment preventing scale application)
• Refusal to participate

Individual participant data will not be shared due to privacy and ethical considerations. De-identified data may be available from the corresponding author upon reasonable request.

Outcome assessors were blinded to group allocation to reduce assessment bias. Participants and care providers were aware of the intervention due to the nature of the study, as antiemetic timing could not be concealed.