What Drugs Are Used In General Anesthesia?

After consenting my patients for general anesthesia, I’m occasionally asked what drugs will be used during surgery. Without going into too much detail, I refer to our agents by general classes: volatiles, narcotics, muscle relaxants, hypnotics, and reversals. The more medically-inclined patients will often ask for specific names too. Here are the agents I typically use for a straightforward general anesthetic. Keep in mind that anesthetics are tailored for each patient.

drugs-anesthesia
Anesthesia goodness!

Once a patient gets to the operating room, the surgery team calls a “timeout” where they discuss the planned procedure, antibiotic prophylaxis, positioning, equipment, and verify that the patient and site of surgery are indeed correct. At this point, the anesthesia team begins the anesthetic (termed “induction”).

Induction

I’ll begin intravenous induction with fentanyl (a potent narcotic offering profound but short-lived pain relief) followed by lidocaine (a local anesthetic to attenuate the response to laryngoscopy). After a few seconds, I’ll start administering the mainstay of modern IV anesthesia – propofol. While this “milk of amnesia” has earned a horrible stigma following Michael Jackson’s (unsupervised) use and ultimate demise, it’s really a fantastic agent which we routinely use to induce and often times maintain a state of unconsciousness. After assisting ventilation using a bag-mask technique, I’ll give rocuronium or succinylcholine, muscle relaxants used to optimize conditions for intubating the trachea.

Maintenance

I’ll use sevoflurane (an “anesthesia gas”) to maintain a state of amnesia during the surgery. Most of our volatile agents also offer some degree immobility but no appreciable analgesia. Consequently, a combination of fentanyl, hydromorphone, morphine, Tylenol, and Toradol are used to provide multimodal pain relief. To maintain a patient’s blood pressure, I might use fluids (normal saline, Lactated Ringer’s, Plasmalyte, human albumin, blood products) or vasopressors (phenylephrine, ephedrine, norepinephrine, epinephrine) depending on the circumstances. To help reduce blood pressure, I can deepen the anesthetic (more gas or propofol), provide more pain medications, or use other medications like labetalol, metoprolol, hydralazine or nicardipine.

Emergence

To reverse the effects of neuromuscular blockade, glycopyrrolate (an antimuscarinic) and neostigmine (an acetylcholinesterase inhibitor) are used. Once spontaneously breathing, I’ll give the patient Zofran (anti-emetic), titrate in a little more long acting narcotic, and extubate.

Hopefully this simplified overview illustrates the general sequence of agents we administer. Feel free to drop a comment if you need more clarification! 🙂

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2 Comments
  1. Adnane Lahlou says

    The use of lidocaine is quite interesting, fond a bit of it myself, what dose do you usually use?

    1. Rishi says

      I’ll mix the lidocaine (1 mg/kg) with the propofol prior to induction. If I’m giving an IV premedication (like midazolam), I’ll mix the lidocaine with it to sort of “prime” the vein for the induction process.

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