1. Bob’s Bet COPYRIGHT © 2014, ALL RIGHTS RESERVED From the Publishers of

2. Copyright © 2014 Terms of Use The Consult Guys ® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the Consult Guys ® slide sets constitutes copyright infringement.

3. Copyright © 2014 Dear Consult Guys; We were hanging out in the preadmission testing center the other day when a woman was being given instructions prior to colonoscopy to be done next week under general anesthesia. Her procedure was to be done in the afternoon and she was told not to have anything to eat or drink from midnight the night before. I thought that our policy was incorrect and that she could undergo general anesthesia 4-6 hours after clear liquids. One of the other guys said that general anesthesia is safe when done after only a 2 hour fast following clear liquids. Is our policy incorrect based on the evidence? Dear Consult Guys; We were hanging out in the preadmission testing center the other day when a woman was being given instructions prior to colonoscopy to be done next week under general anesthesia. Her procedure was to be done in the afternoon and she was told not to have anything to eat or drink from midnight the night before. I thought that our policy was incorrect and that she could undergo general anesthesia 4-6 hours after clear liquids. One of the other guys said that general anesthesia is safe when done after only a 2 hour fast following clear liquids. Is our policy incorrect based on the evidence?

4. Copyright © 2014 Fast from midnight (“NPO after midnight”) Six hour fast Four hour fast Two hour fast NPO (non-nil per os)

5. Copyright © 2014 Hint for Audience “While it is desirable that there be no solid matter in the stomach when chloroform is administered, it will be found very salutary to give a cup of tea or beef-tea about two hours previously.” Lord Joseph Lister, 1882

6. Copyright © 2014  1946: Mendelson. High incidence of pulmonary aspiration among OB patients receiving general anesthesia  Animal data: lung injury related to volume of aspirate and decreased pH  Recent data: Pulmonary aspiration rare.  Fasting can lead to dehydration, hypovolemia, hypoglycemia Key Points

7. Copyright © 2014

8. Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration (Am Soc of Anesthesiologists, 1999) Pulmonary aspiration is rare Little relation between fasting duration and gastric volume or pH Prolonged fasting may have adverse effects Liquids and solids are eliminated differently from the stomach

9. Copyright © 2014 Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration (Am Soc of Anesthesiologists, 2010) Minimum preoperative fasting for healthy people  Clear liquids – two hours  Water, fruit juice without pulp, clear tea, black coffee  Light meal (toast + liquid) – six hours  Regular meal (fried or fatty food) – eight hours

10. Copyright © 2014 Consult Guys Replies Clear liquids safe up to two hours before general anesthesia

11. COPYRIGHT © 2014, ALL RIGHTS RESERVED Produced by and