The induction of general anesthesia in patients undergoing cardiac surgery is often times different than non-cardiac surgery. At many institutions, these inductions tend to center heavily around high dose opioids due to the hemodynamic stability conferred by narcotics. When talking about fentanyl, this translates to anywhere from 50 – 100 mcg/kg. Yes, that can be upwards of 4,000 MICROGRAMS OF FENTANYL (as pictured!) Although fentanyl is typically regarded as a “short acting” agent, in these doses, significant uptake by fatty tissues with subsequent redistribution makes this a much longer acting narcotic.
In the era of enhanced recovery protocols and balanced anesthetics, this isn’t my preferred induction style; however, I’ve done it several times and am always impressed by the process. The most important consideration is the onset of chest wall rigidity – likely a central nervous system mediated spasm of the chest wall – which significantly limits our ability to ventilate. For these inductions, I usually give enough narcotic till the patient is unconscious, then push a neuromuscular blocking agent, and then complete the induction by securing the airway and minimizing the amount of volatile anesthetic I use.
Drop me a comment below with questions! 🙂