General Anesthesia

BACK TO CURRICULUM

1. Introduction

Learn the basics of general anesthesia, the physiology of unconsciousness and an overview of the pharmacology.

4. Airway and Ventilation

Master the fundamentals of airway management and effective ventilation.

2. Phases of General Anesthesia

Understand the key phases of general anesthesia.

5. Monitoring & Depth Assessment

Ensure patient safety by assessing monitoring tools that track depth of anesthesia.

3. The 5 A's of Anesthesia

Learn the five core goals of anesthesia: analgesia, amnesia, anesthesia, akinesia, and autonomic control.

6. Complications & Rescue Algorithms

Be prepared to recognize complications and apply rescue algorithms effectively.

1. Introduction

What is General Anesthesia?

Video 1

This video explains the key differences between general anesthesia and sedation, breaking down the depths of anesthesia and their impact on patient care, surgical conditions, and anesthetic planning.

Physiology of Unconsciousness

Video 2

This video explores how general anesthesia works beyond pain control, affecting memory, muscle tone, and brain connectivity. Learn how drugs like propofol alter neural function and why recovery from unconsciousness is a complex, gradual process.

Pharmacology Overview

Video 3

This pharmacology lecture covers the mechanisms, stages, and effects of general and local anesthetics. Learn how key agents like propofol, ketamine, and bupivacaine work at the receptor level, and how they produce unconsciousness, analgesia, or nerve blockade.

Brief Anesthesia

This article provides a broad overview of general anesthesia, including its uses, mechanisms, drug types, risks, and recovery process, ideal for patients and early learners alike.

General Anesthesia Techniques

The Royal College of Anesthesia Novice Guide outlines fundamental anesthetic techniques, offering practical advice on induction, maintenance, airway management, and patient monitoring. Perfect for beginners in anesthesia training.

2. Phases of General Anesthesia

Video 1

Pre-Induction

Learn the "6 Ps" of anesthesia planning: Patient, Procedure, Pathology, Preparation, Place, and Personnel.

And the "4 Ms" of preparation: Machine check, MABELS, Monitoring, and Medications.

Video 2

Induction

This video provides a clear, step-by-step walkthrough of general anesthesia induction, covering preoxygenation, drug administration, airway management, and safety checks for smooth and effective initiation.

Video 3

Maintenance

Explore the maintenance phases of general anesthesia with a focus on autonomic responses, physiologic changes, and how anesthetic depth affects patient stability during surgery.

Video 4

Emergence

Watch a real-time example of emergence from anesthesia and awake extubation, with step-by-step guidance and clinical pearls on timing, safety checks, and airway management.

Exam-Focused Guide

Geeky Medics offers a clear, structured guide to the induction and maintenance of general anesthesia, covering key steps, drug choices, monitoring, and clinical tips for learners and trainees.

Resident and Clinician Guide

AnesKey provides a comprehensive overview of induction, maintenance, & recovery from general anesthesia, detailing pharmacologic strategies, physiologic monitoring, and key considerations across all stages.

3. The 5 A's of Anesthesia

Amnesia

• Give a small benzodiazepine or maintain ≥0.5 MAC volatile to block memory.
• Prevents postoperative psychological distress from intra-op recall.
• Verify depth with BIS < 60 or end-tidal MAC display.
• Re-dose hypnotic if case unexpectedly prolongs.

1. Practice Advisory for Intraoperative Awareness and Brain Function Monitoring: A Report by the American Society of Anesthesiologists Task Force on Intraoperative Awareness. Anesthesiology 2006;104:847–64. https://doi.org/10.1097/00000542-200604000-00031.

2. Chung HS. Awareness and recall during general anesthesia. Korean J Anesthesiol 2014;66:339–45. https://doi.org/10.4097/kjae.2014.66.5.339.

Anesthesia

• Induce with propofol/etomidate/ketamine or sevoflurane mask; maintain with volatile or TIVA.
• Ensures unconsciousness so patient doesn’t perceive surgery.
• Adjust infusion or vaporizer to keep patient unresponsive but hemodynamically stable.
• Confirm return of protective reflexes before extubation.

1. Hosseinzadeh H, Eidy M, EJ Golzari S, Vasebi M. Hemodynamic Stability during Induction of Anesthesia in ElderlyPatients: Propofol + Ketamine versus Propofol + Etomidate. J Cardiovasc Thorac Res 2013;5:51–4. https://doi.org/10.5681/jcvtr.2013.011.

2. Lu Z, Zheng H, Chen Z, Xu S, Chen S, Mi W, et al. Effect of Etomidate vs Propofol for Total Intravenous Anesthesia on Major Postoperative Complications in Older Patients: A Randomized Clinical Trial. JAMA Surg 2022;157:888. https://doi.org/10.1001/jamasurg.2022.3338.

Analgesia

• Load with fentanyl/remifentanil ± adjuncts; top up before incision and closure.
• Blunts sympathetic surges, reduces peri-op opioid needs later.
• Combine with regional block when possible for opioid-sparing effect.
• Multimodal plan: NSAID or acetaminophen given early.

1. Kim SH, Stoicea N, Soghomonyan S, Bergese SD. Intraoperative use of remifentanil and opioid induced hyperalgesia/acute opioid tolerance: systematic review. Front Pharmacol 2014;5:108. https://doi.org/10.3389/fphar.2014.00108.

2. O’Neill A, Lirk P. Multimodal Analgesia. Anesthesiol Clin 2022;40:455–68. https://doi.org/10.1016/j.anclin.2022.04.002.

Akinesia

• Use succinylcholine for rapid airway control or rocuronium/vecuronium for maintenance.
• Provides still field and prevents reflex movement that could harm surgeon or patient.
• Titrate with nerve stimulator, aiming 0–1 twitch during surgery.
• Reverse with sugammadex or neostigmine/glycopyrrolate before wake-up.

1. Muñoz-Martínez T, Garrido-Santos I, Arévalo-Cerón R, Rojas-Viguera L, Cantera-Fernández T, Pérez-González R, et al. [Contraindications to succinylcholine in the intensive care unit. A prevalence study]. Med Intensiva 2015;39:90–6. https://doi.org/10.1016/j.medin.2014.07.002.

2. Bucheery BA, Isa HM, Rafiq O, Almansoori NA, Razaq ZAA, Gawe ZA, et al. Residual Neuromuscular Blockade and Postoperative Pulmonary Complications in the Post-anesthesia Care Unit: A Prospective Observational Study. Cureus n.d.;15:e51013. https://doi.org/10.7759/cureus.51013.

Neurological Examination

• Balance volatiles, opioids, β-blockers, vasopressors to keep MAP within ±20 % of baseline.
• Maintains organ perfusion and minimizes surgical bleeding.
• Active warming and fluids to prevent stress-induced hypothermia or hypotension.
• Anticipate sympathetic surges at laryngoscopy, incision, and emergence.

1. Meng L, Yu W, Wang T, Zhang L, Heerdt PM, Gelb AW. Blood Pressure Targets in Perioperative Care: Provisional Considerations Based on a Comprehensive Literature Review. Hypertension 2018;72:806–17. https://doi.org/10.1161/HYPERTENSIONAHA.118.11688.

2. THE AMERICAN SOCIETY OF ANESTHESIOLOGISTS. Maintaining blood pressure levels measured before entering O.R. may improve outcomes. Maintaining Blood Pressure Levels Measured before Entering OR May Improve Outcomes 2015. https://www.asahq.org/about-asa/newsroom/news-releases/2015/10/maintaining-blood-pressure-levels (accessed June 15, 2025).

5 A's of Anesthesia Explained

4. Airway & Ventilation

Video 1

A Comprehensive Overview

Learn about the key devices used to establish and maintain an airway in patients with compromised breathing. This video covers tools ranging from basic adjuncts to advanced airway devices used in critical care.

Video 2

The First Two Steps

Master the foundational steps of airway management, from opening and clearing the airway to using adjuncts and performing effective bag-mask ventilation. This video guides you through each technique to ensure safe and effective patient care in emergencies.

Video 3

Airway Devices

Start here for an introduction to airway management devices and what they’re used for. This video kicks off a series that explores each device in detail.

Detailed Concepts

This AMBOSS overview is a detailed, high-yield resource for medical trainees covering airway management concepts, algorithms, & device selection. Ideal for clinical reference & exam preparation.

Visual Summary

Osmosis provides a simplified, visual summary of airway management designed for foundational learning. Great for students building early understanding of core concepts.

5. Monitoring & Depth Assessmment

Monitoring Equipment

Video 1

This video explains and demonstrates the essential monitors anesthesiologists use during surgery, covering standard vital signs like ECG, pulse oximetry, capnography, and blood pressure to ensure patient safety.

Bispectral Index Monitoring

Video 2

This in-service video provides an overview of BIS (Bispectral Index) monitoring, explaining how it assesses depth of anesthesia, guides drug titration, and helps prevent intraoperative awareness.

Anesthestic Equipment

Geeky Medics provides a clear overview of essential anesthetic equipment, covering machines, circuits, vaporizers, and safety features. Ideal for students and early trainees.

ASA Standards for Monitoring

The ASA’s official Standards for Basic Anesthetic Monitoring outline the minimum monitoring requirements for all patients receiving anesthesia, ensuring safety through continuous assessment of oxygenation, ventilation, circulation, and temperature.

6. Complications & Rescue Algorithms

Common Risks

Video 1

In this episode of Behind the Drapes, Frankie Lima breaks down the potential risks of anesthesia, including awareness, eye injuries, vocal cord damage, and neurologic complications, to help patients make informed decisions before surgery.

Awareness

Video 2

This video explores the rare but serious phenomenon of anesthesia awareness, why it happens, who’s at risk, and how to reduce the chance of waking up during surgery using natural, non-pharmacologic strategies.

Malignant Hyperthermia

Video 3

This video offers a concise overview of malignant hyperthermia, covering its causes, symptoms, diagnosis, and treatment. A high-yield resource for recognizing and managing this rare but life-threatening anesthetic emergency.

Overview of Complications

Geeky Medics provides a clear and structured overview of anesthesia complications, ranging from common side effects to rare but serious risks like anaphylaxis, aspiration, and nerve injury, ideal for learners and clinical prep.

Emergency Algorithms

This resource compiles essential anesthesia algorithms for crisis management, covering scenarios like malignant hyperthermia, local anesthetic toxicity, and failed intubation. A must-have reference for quick decision-making in high-stakes situations.