Endotracheal and intranasal epinephrine in severely asphyxic bradycardic newborn lambs

The Best Route for Neonatal Resuscitation: A Study on Epinephrine Administration

When it comes to neonatal resuscitation, speed and efficiency are critical. Intravenous (IV) epinephrine is the preferred method for delivering life-saving treatment, but in real-world scenarios, it isn’t always readily available. Sometimes, a lack of equipment or trained personnel can delay IV access, making it essential to consider alternative routes. A recent study sheds light on this issue by comparing intravenous, endotracheal (ET), and intranasal (IN) epinephrine in severely asphyxiated newborn lambs.

Objective of the Study

The study aimed to assess the effectiveness of different routes of epinephrine administration by comparing the time to return of spontaneous circulation (ROSC) and post-ROSC haemodynamics. Specifically, researchers investigated the outcomes for intravenous, endotracheal, and intranasal epinephrine in lambs that experienced severe asphyxia and bradycardia.

How the Study Was Conducted

In this experiment, near-term lambs were subjected to severe asphyxia by clamping the umbilical cord, resulting in a heart rate below 60 beats per minute and a blood pressure around 10 mm Hg. Resuscitation efforts began with ventilation and chest compressions. The lambs were then randomly assigned to receive epinephrine via one of three routes: intravenous (0.02 mg/kg), endotracheal (0.1 mg/kg), or intranasal (0.1 mg/kg). If ROSC was not achieved after three doses of the assigned treatment, rescue intravenous epinephrine was administered. After achieving ROSC, the lambs were ventilated for 60 minutes to monitor their recovery.

Key Findings

The results were quite telling:

• Intravenous Epinephrine: Achieved ROSC in 100% of the lambs, with an average time to ROSC of 173 seconds. This group also exhibited the highest blood pressure and cerebral oxygen delivery immediately post-ROSC.

• Endotracheal Epinephrine: Achieved ROSC in 57% of the lambs, with an average time to ROSC of 360 seconds. This group maintained the highest blood pressure over the 60-minute observation period.

• Intranasal Epinephrine: Achieved ROSC in 71% of the lambs, with an average time to ROSC of 401 seconds. Although effective, this route was slower compared to intravenous administration.

Statistical analysis indicated that intravenous epinephrine was significantly faster in achieving ROSC compared to intranasal epinephrine. Additionally, while endotracheal epinephrine maintained better blood pressure over time, intravenous epinephrine provided superior immediate outcomes.

Conclusion

The study reinforces the current neonatal resuscitation guidelines by demonstrating that intravenous epinephrine is the most effective route for achieving a swift return of spontaneous circulation and optimal haemodynamics. However, it also highlights the need for alternative options like endotracheal and intranasal epinephrine when intravenous access is delayed or unavailable. Ensuring that medical teams are prepared with these alternative methods can significantly impact the outcomes in critical neonatal resuscitation scenarios.

Future studies in human neonates will be necessary to validate these findings in clinical settings, but this lamb model offers valuable insights into the limitations of alternative epinephrine delivery routes. These results emphasize that while non-IV routes can be lifesaving when IV access is not possible, IV epinephrine should remain the gold standard in neonatal resuscitation efforts.

Understanding these findings helps in planning better resuscitation strategies and ensuring that, even in challenging circumstances, every possible measure is taken to support the survival and recovery of newborns in distress.

The article is available here: https://fn.bmj.com/content/early/2024/09/04/archdischild-2024-327348.long