Fentanyl (Sublimaze) is the most common synthetic narcotic I administer in the OR and the ICU. It is ~100x more potent than morphine and associated with many of the same side effects as other mu-opioid agonists – nausea, vomiting, constipation, respiratory depression, hallucinations, and sedation. Fentanyl can be delivered through several routes: intravenous, intrathecal (off-label), transdermal (fentanyl patch), intranasal, sublingual, and as a lozenge (“fentanyl lollipops”). Many of these routes are possible due to the medication’s highly lipophilic nature.

For ~50 years, fentanyl has come under fire for its dangers in recreational use. Often times, patients are shocked when they receive fentanyl intraoperatively, in the PACU, or in the ICU given its societal stigma; however, from a clinical/therapeutic standpoint, this medication offers several advantages – clean metabolite profile, inexpensive, relatively short bolus half-life (keep in mind that the context-sensitive half-life increases drastically after ~2-3 hours of infusion), lack of histamine release, etc.

Depending on the surgery, I’ll routinely give anywhere from 100 mcg to over 1000 mcg of fentanyl for analgesia and as an general anesthetic adjunct. I use it in tandem with agents like propofol and ketamine for bedside procedures in the ICU (bronchoscopy, chest tube placement, vac changes) and, despite how much I hate running narcotic DRIPS, as a form of sedation for mechanical ventilation. I also consider a predictable form of “rescue analgesia” for patients with intractable pain.

Drop me comments with questions below! 🙂

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  1. Hey Rishi,
    Quick question for you. Intubation of patients in heart failure or with a cardiomyopathy in an intensive care setting. What are your thoughts and experience with using moderate-dose fentanyl (10-15 mcg/kg) as a sole agent for sedation/analgesia along with a paralytic for intubation.

    Since these patients will likely be intubated for a few days, the prolonged respiratory depression is less of a worry. And taking a lesson from the cardiac anesthesia yesteryear there are very few induction techniques that are as stable as a opioid-only technique especially in patients with decreased myocardial function and/or severe CAD that has yet to be corrected via CABG or PCI.

    Etomidate is the defacto drug for cardiac patients in my ICU, however like you I have concerns regarding adrenal suppression in the ICU population. And unfortunately in my ICU push dose Ketamine is not readily available. I’ve done opioid-only inductions in the OR for LVAD patients, but I was curious about the applicability in the ICU setting.

    Thanks in Advance,


    • Great question! I think this really hinges on logistics too. Getting a “moderate-dose” of fentanyl is sometimes difficult in a pinch, but in general, I’ll give a very low dose of propofol just for the true hypnotic effect and chase it with succinylcholine + narcotic. I’ve seen rigid chest several times from high dose narcotic inductions, and it can be challenging (especially since the positive pressure you apply can affect the hemodynamics in these patients). I also routinely give pressors/inotropes during induction (epinephrine, norepi, phenylephrine, calcium) to mitigate the effects of induction. Once the airway is secured, I’ll use more narcotic than volatile agent (in the OR) to keep the patient stable while I’m placing lines. In the ICU, I’ll usually stick with narcotic pushes/infusions and dexmedetomidine for sedation.

      As you can imagine, it all just depends on how much the patient has compensated for his/her comorbidities.


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