Circulation 36,825 • Volume 18, No. 4 • Winter 2003   Issue PDF

Virtual Anesthesia Machine Has Worldwide Impact

Sem Lampotang, PhD

The Virtual Anesthesia Machine (VAM)1 at is a free, interactive, model-driven web simulation of a generic, traditional anesthesia machine. Instead of complex, dimensional drawings of an anesthesia machine, VAM presents a simplified, transparent mental model designed to help viewers appreciate and retain basic concepts and acquire insight. Gas “molecules” are made visible and are color-coded (4 user-selectable gas color codes: ISO, Georgian, Japanese, US). Users can adjust 30 controls and observe in real time the essential effects of their interventions on gas pressures, flows, compositions and volumes. Machine faults can be simulated. Online help to use the simulation is available as an animated tutorial. The simulation can be used off-line and features user-selectable legends in 19 languages (Albanian, Arabic, Chinese, Czech, Dutch, English, Farsi, French, Georgian, German, Greek, Hebrew, Italian, Japanese, Korean, Portuguese, Russian, Spanish, and Turkish).

The VAM simulation has more than 12,000 registered users, is used in more than 350 programs worldwide, and has received favorable peer reviews.2,3 The website received 1.4 million hits in the last 12 months ending in September 2003. The VAM simulation deliberately emphasizes graphics with minimal text. Many of the learning objectives are imbedded within the VAM simulation and are not obvious to those who are reticent to explore on their own. Therefore, a subset of users whose learning style requires more “hand-holding” may obtain only minimal benefit from using the VAM simulation on their own.

To enable a greater number of users and programs to benefit from the VAM simulation to its full potential, the Anesthesia Patient Safety Foundation funded the development of the first chapter in a proposed 8-chapter anesthesia machine workbook. The first chapter was designed to encourage users to more fully explore the VAM simulation and to cover normal function of traditional anesthesia machines by making use of existing simulations within the VAM.

The workbook was divided into 3 main sections designed for instructional use or self-paced learning. Part 1 is a discussion of basic concepts in anesthesia machine function and design. The reader is guided through a process of progressively building an anesthesia machine starting with the most rudimentary design and culminating in the traditional circle system. Part 2 explains how to use the VAM simulation, its outputs (36), and user-adjustable inputs (30). Part 3 contains safety-related, structured exercises, including post-test questions, on the high pressure, low pressure, breathing circuit, manual ventilation, mechanical ventilation, and scavenging systems. Each exercise is presented, whenever possible, as a clinical scenario.

The workbook was drafted in Microsoft Word and converted to a read-only PDF format for free viewing and printing over the web. The original English version was posted to the Web on November 14, 2002, as a 688 KB PDF document. In September 2003, the workbook was switched to a FlashPaper (Macromedia, San Francisco, CA) format (705 KB) to preserve image quality when viewing the document electronically in different window sizes. Flash player (a free download from Macromedia; is required to view and print the workbook. The FlashPaper document can be printed (color printer recommended) and used as a workbook. Alternatively, it may be viewed simultaneously with the VAM simulation by toggling back and forth between separate web browser windows containing the two applications.

Snapshot of a sample simulation from the Virtual Anesthesia Machine website.

Chapter 1 of the APSF workbook was accessed 1,700 times/month on average and has received favorable peer review: “The manual fills a void that has existed in the field of anesthesia.”4 This review concludes by recommending the manual to all anesthesia providers.4

In less than 12 months since it has been publicly available, chapter 1 of the APSF workbook has been translated and posted to the VAM website in German (April 2003), Korean (May 2003), Chinese (September 2003), and Italian (September 2003). The APSF workbook has also been incorporated as part of the curriculum in many institutions worldwide including the University of Pennsylvania, West Virginia University, University of Kentucky, Cleveland Clinic Foundation, University of Louisville, Evanston Northwestern School of Anesthesia, University of Tennessee Health Science Center, Seoul National University, and the University of Florida.

Translations to Spanish, French, Arabic, Farsi, Japanese, and Georgian are currently underway. The translations are peer-reviewed by native-speaking anesthesiologists who are knowledgeable about anesthesia machines. Rapid translation of the APSF workbook in different languages is indicative of the perceived value of the APSF workbook and has helped to disseminate APSF’s message on patient safety overseas. For further information on the APSF workbook or to volunteer for translation of the workbook into other languages, please contact Sem Lampotang, APSF Committee on Education and Training at [email protected].

Sem Lamptotang, PhD, is Project Coordinator, Virtual Anesthesia Machine: An Interactive Model-Driven Simulation, University of Florida.


  1. Lampotang S, Dobbins W, Good ML, et al. Interactive, web-based, educational simulation of an anesthesia machine (abstract). J Clin Monit Comput 2000;16:56-7.
  2. Olympio MA. The Virtual Anesthesia Machine (review). Anesthesiology 2002;96:1281.
  3. Doyle DJ. The Virtual Anesthesia Machine” (version 8.32) (review). Can J Anaesth 2003;50:206-7.
  4. Gaiser RR. The Anesthesia Patient Safety Foundation Anesthesia Machine Workbook (review). Anesth Analg 2003;97:929.