What is the administration of epinephrine (adrenaline) through an endotracheal tube (ETT)?

From the Guidelines

Epinephrine can be administered through an endotracheal (ET) tube in emergency situations when intravenous access is not available, with a recommended dose of 0.1 milligrams per kilogram (0.1 milliliter per kilogram of the 1 milligram per milliliter concentration) as stated in the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1.

Key Considerations

• The dose for ET administration is higher than the standard IV dose, reflecting the less reliable absorption through this route.
• When administering epinephrine via ET tube, it is crucial to dilute the medication with normal saline and follow with positive pressure ventilations to enhance absorption and distribution.
• Establishing IV or intraosseous access should remain a priority, as the ET route is considered a temporary bridge due to its unpredictability and potential delay in absorption.

Administration Guidelines

• The medication should be diluted with 5-10 mL of normal saline to improve absorption.
• Several positive pressure ventilations should follow the administration to help disperse the medication.
• The ET route may produce lower blood levels compared to IV administration, necessitating careful monitoring and potential adjustment of dosing.

Clinical Context

• Epinephrine works through alpha and beta-adrenergic effects to increase systemic vascular resistance, improve coronary and cerebral perfusion pressure, and enhance myocardial contractility during resuscitation.
• While the ET route is an option, it should be considered a bridge until more effective vascular access can be established, given the unpredictability and potential delay in absorption.
• The guidelines from the 2020 American Heart Association 1 and the international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations 1 support the use of epinephrine via ET tube in specific circumstances, emphasizing the importance of prompt establishment of more reliable vascular access.

From the Research

Administration of Epinephrine through Endotracheal Tube

• The endotracheal route for drug administration provides a rapid means of accessing the systemic circulation when intravenous routes cannot be established in emergent situations 2.
• Epinephrine can be administered through an endotracheal tube, but the optimal dosage and diluent are unknown 3, 4.
• Studies have shown that endotracheal administration of epinephrine is unreliable and not reproducible in both normotensive and shock animals 3.
• A prospective, randomized, laboratory comparison of increasing doses of endotracheal epinephrine found that only a dose of 0.3 mg/kg successfully caused an increase in blood pressure, observed 2 min after administration, and lasting for 10 min 5.

Comparison of Administration Routes

• Epinephrine was equally effective by the intraosseous, central intravenous, and peripheral intravenous routes in terms of time to onset of action, time to peak effect, and magnitude of effect on systolic, diastolic, and mean arterial pressures in both shock and non-shock animals 3.
• The endotracheal route of administration was unreliable and not reproducible in either normotensive or shock animals 3.
• The duration of effect was significantly longer for the intraosseous route of administration 3.

Dosage Recommendations

• Endotracheal administration of epinephrine 0.02 mg/kg (twice the IV dose) is recommended when IV access is unavailable during cardiopulmonary resuscitation 5.
• A dose of 0.3 mg/kg was found to be effective in increasing blood pressure, but this is 10-fold the currently recommended dose 5.
• Clinical studies using larger doses of endotracheal epinephrine and their use as first-line therapy in cardiac arrest are warranted 5.