Final answer:
The next step in the treatment of refractory ventricular fibrillation after the described interventions would be to administer another 1 mg dose of epinephrine according to ACLS guidelines.
Step-by-step explanation:
In the situation where a patient is in refractory ventricular fibrillation and has already received high-quality CPR, a dose of epinephrine after the second shock, and an antiarrhythmic drug after the third shock, the next medication to consider would typically be an additional dose of epinephrine, unless otherwise contraindicated or if alternative therapy is recommended by current advanced cardiac life support (ACLS) guidelines.
As the team leader, your decisions should be based on the ACLS protocol, which often requires the administration of epinephrine every 3-5 minutes during cardiac arrest. Therefore, if sufficient time has elapsed since the first dose, the next step would generally be to administer another dose of epinephrine 1 mg intravenously or intraosseously. This is because epinephrine can increase coronary and cerebral blood flow during the CPR compressions, improving the chance of return of spontaneous circulation (ROSC).
Sodium bicarbonate is not routinely used in cardiac arrest without specific indications such as hyperkalemia or pre-existing bicarbonate-responsive acidosis. The mention of continuing with antiarrhythmic drugs or high epinephrine doses might be considered based on individual patient factors, but these are not standard initial options after the given treatments. It is important to consult the most recent ACLS guidelines for the precise treatment algorithm.