General anesthesia pharmacology - Medications for induction, maintenance, & emergence

Summary

In this educational video, Max Feinstein, an anesthesia resident at Mount Sinai Hospital, New York, explains the process of general anesthesia. He outlines the key components such as analgesia, amnesia, areflexia, and unconsciousness, and discusses various medications used, including midazolam, fentanyl, lidocaine, propofol, and neuromuscular blockers. He also covers the importance of individualizing the anesthetic plan and touches on the emergence phase, including the use of anti-emetics and reversal agents like sugammadex and neostigmine. The video is an informative guide for anyone interested in understanding the complexities of anesthesia.

Takeaways

• 😷 Max Feinstein is an anesthesia resident at Mount Sinai Hospital in New York City, providing insight into general anesthesia medications.
• 💊 General anesthesia involves a combination of medications to ensure pain control (analgesia), memory loss (amnesia), immobility (areflexia), and unconsciousness.
• 👨‍⚕️ Anesthesia is personalized based on surgery type, patient needs, and various health factors including age, weight, and co-morbidities.
• 🔑 The anesthesia plan is divided into three phases: induction, maintenance, and emergence, each requiring different medications and considerations.
• 🛏️ Induction begins with midazolam for anxiety and memory loss, followed by fentanyl for pain control and to reduce sympathetic response.
• 💉 Lidocaine is used to lessen injection pain and reduce the amount of anesthesia needed, also aiding in post-operative recovery.
• 💊 Propofol is a common induction and maintenance anesthetic, requiring attention to its vasodilatory effects on blood pressure.
• 💪 Intubation may require the use of paralytics like succinylcholine or rocuronium to relax the patient for optimal surgical conditions.
• 🌫️ Sevoflurane and isoflurane are examples of volatile anesthetics used for maintenance, chosen based on surgery duration and patient needs.
• 🔄 Emergence involves reversing paralysis with medications like sugammadex or neostigmine, with considerations for side effects and safety.
• 🤮 Anti-emetics like ondansetron are used to prevent post-operative nausea and vomiting, timed to take effect as the patient wakes up.

Q & A

What is the definition of general anesthesia according to the video?

General anesthesia is defined as enough anesthesia that a patient does not move at all when there is a painful stimulus, specifically during surgery.

What are the four components of an anesthetic plan mentioned in the video?

The four components of an anesthetic plan are analgesia (pain control), amnesia (no memory of the event), areflexia (no movement), and unconsciousness.

Why is midazolam administered during anesthesia induction?

Midazolam is administered for its anxiolytic effects, to put the patient at ease, and for its amnestic properties, causing memory fuzziness or loss post-administration.

What is the role of fentanyl in anesthesia?

Fentanyl, an opioid, is used to decrease the sympathetic drive during direct laryngoscopy, reduce the sympathetic response to surgical stimuli, and minimize the amount of other anesthetics needed for general anesthesia.

Why is lidocaine included in the anesthesia plan?

Lidocaine is included to reduce pain from propofol injection, decrease the amount of anesthetics needed, reduce post-operative pain, and reduce post-operative ileus.

What are the common side effects of propofol?

Propofol is a vasodilator, which can cause a drop in blood pressure, requiring the use of vasopressors like phenylephrine and ephedrine to counteract this effect.

Why is succinylcholine used for intubation?

Succinylcholine is a depolarizing neuromuscular blocker used to relax the patient for intubation, with effects lasting about five minutes.

What is the purpose of dexamethasone in the anesthesia plan?

Dexamethasone is a steroid used as an anti-emetic to prevent nausea and vomiting after surgery.

How does sevoflurane differ from isoflurane in terms of usage?

Sevoflurane is typically used for shorter cases, while isoflurane, with its cardiac benefits, is preferred for longer cases, although it takes longer to wear off.

What is the primary use of sugammadex in anesthesia?

Sugammadex is used to reverse the effects of aminosteroid paralytics, specifically rocuronium, and is the newest medication for this purpose in anesthesia.

What are the considerations when choosing between neostigmine and glycopyrrolate versus sugammadex for reversing paralysis?

The choice depends on the patient's condition, the side effect profile, the onset of action, and the depth of paralysis. Sugammadex has a unique side effect profile, including the potential to render hormonal birth control ineffective.

Why is ondansetron included in the emergence plan?

Ondansetron is an anti-emetic with a peak effect time of about half an hour, used to prevent discomfort from nausea and vomiting as the patient wakes up from anesthesia.

What is a potential side effect of ondansetron that should be considered before administration?

Ondansetron can be a QT prolonging medication, so it may not be safe for patients with a prolonged QTc interval.