Medications for Stroke Patients in Emergency Medical Services (EMS)
The primary medication administered to eligible stroke patients in the EMS setting is supplemental oxygen for hypoxemic patients (oxygen saturation <94%), while definitive reperfusion therapies like intravenous tissue plasminogen activator (tPA) are typically administered after hospital arrival. 1, 2
Initial EMS Management
- Supplemental oxygen should be administered to hypoxemic stroke patients (oxygen saturation <94%) or those with unknown oxygen saturation 1, 2
- EMS providers should establish IV access to prepare for potential hospital interventions 3
- Blood glucose should be checked in the field if possible, as hypoglycemia can mimic stroke symptoms 2
- For patients with persistent chest pain, intravenous morphine may be considered, though caution is advised in unstable angina/NSTEMI due to association with increased mortality 1
Blood Pressure Management in EMS
- Unless the patient is hypotensive (systolic blood pressure <90 mm Hg), prehospital intervention for blood pressure is not recommended 1, 2
- Blood pressure management is typically reserved for the hospital setting, particularly before thrombolytic therapy 4
Hospital-Based Acute Stroke Medications
While not typically administered in the EMS setting, it's important to understand the medications that will be given upon hospital arrival:
Thrombolytic Therapy
- Intravenous alteplase (tPA) is the standard of care for eligible acute ischemic stroke patients within 4.5 hours of symptom onset 5, 6
- The recommended dose is 0.9 mg/kg (maximum 90 mg) with 10% given as bolus over 1 minute and 90% as infusion over 60 minutes 6, 7
- Blood pressure must be <185/110 mmHg before tPA administration and maintained <180/105 mmHg for 24 hours after treatment 4
Antithrombotic Therapy
- For patients not receiving thrombolysis, early aspirin therapy is recommended 5, 8
- Aspirin is typically administered at a dose of 81-325 mg 9, 8
Critical Considerations for EMS
- Time is critical - EMS providers should rapidly identify stroke symptoms, establish time of symptom onset, and provide pre-arrival notification to the receiving hospital 2, 10
- EMS should transport patients to the most appropriate stroke center when possible 10, 6
- Stroke assessment scales should be used in the field to identify potential stroke patients 2
- Documentation of the last known normal time is essential for determining eligibility for time-sensitive interventions 2
Common Pitfalls to Avoid
- Delaying transport to administer medications in the field - rapid transport to a stroke center is the priority 10
- Failing to notify the receiving hospital of a potential stroke patient, which can delay in-hospital treatment 2
- Administering antihypertensive medications in the field without specific indications 1, 2
- Missing the documentation of exact time of symptom onset or last known normal time 2
Remember that the primary role of EMS in stroke care is rapid identification, supportive care, and expedited transport to an appropriate facility where definitive treatments can be administered.