Pharmacokinetics and pharmacodynamics of endotracheal versus supraglottic airway epinephrine in a healthy neonatal piglet model

Background

Epinephrine remains the only vasopressor recommended for neonatal resuscitation. During cardiopulmonary resuscitation (CPR), it can be administered intravenously, intraosseously, or through an endotracheal tube (ETT). However, the supraglottic airway (SGA) has emerged as a potential alternative for epinephrine delivery. This study aimed to compare the pharmacokinetics and pharmacodynamics of epinephrine administration via ETT, the top of the SGA, and the bottom of the SGA.

Study Design and Methods

A controlled experiment was conducted using newborn piglets (n = 5 per group). The piglets were anesthetized, randomized to receive epinephrine via either ETT or SGA, and surgically instrumented for continuous hemodynamic monitoring. Those assigned to the SGA group underwent further randomization to receive epinephrine at either the top or bottom of the SGA.

Physiological parameters, including heart rate (HR), arterial blood pressure, carotid blood flow, and cardiac function (e.g., stroke volume and ejection fraction), were continuously recorded. Blood samples were collected before drug administration and throughout the observation period for pharmacokinetic and pharmacodynamic analysis.

Results

• Hemodynamic Response: Significant changes in HR, carotid blood flow, and cardiac function were observed only following ETT administration of epinephrine.

• Pharmacokinetics: No significant differences in pharmacokinetic parameters were detected between the ETT, SGA top, or SGA bottom routes.

Conclusion

While pharmacokinetic profiles were similar across all administration routes, epinephrine delivered via ETT resulted in significant hemodynamic changes, whereas administration through the SGA did not produce comparable effects.

Clinical Implications

• The findings highlight a potential limitation of SGA for epinephrine administration during neonatal resuscitation.

• Current resuscitation guidelines may need to reconsider the use of SGA as an effective route for epinephrine delivery.

• Future research should explore alternative dosing strategies or modifications to enhance the efficacy of SGA epinephrine administration.

• Further studies are warranted to assess the effectiveness of SGA-administered epinephrine during neonatal CPR in critical conditions.

This study raises important questions about optimizing epinephrine delivery routes and their impact on neonatal resuscitation outcomes. As research continues to evolve, these findings may influence clinical practice and resuscitation guidelines in neonatal care.