Chemistry and creativity: UNDERSTANDING ANESTHESIA EQUIPMENT
Author:
There have been many exciting changes in anesthesia equipment since the fourth edition was published. Once again we have updated equipment covered in previous editions. New chapters on latex allergy, suction equipment, double-lumen tubes, emergency airway devices, operating room fires, temperature control and the MRI environment have been added. Some of these were covered to some extent as parts of other hapters in previous editions but we felt they needed to be expanded into separate chapters because of the arge amount of information available. During the years since the last edition, anesthesia machines have undergone major changes. The anesthesia ventilator,which in the past was a separate entity, has been integrated with the machine and the breathing system.
At the same time anesthesia ventilators have gained more features and now more closely resemble critical
care ventilators. These chapters have been expanded. One device that has had a great impact on anesthesia
practice is the supraglottic airway. Anumber of new devices from different manufacturers have become available and the indications for these devices have continued to grow. This chapter has been greatly expanded. Pressure- and flow-volume loops were discussed in the fourth edition. Many of the newer anesthesia machines and physiological monitors include them. We have expanded this section in the hope that this will make it easier to interpret them and appreciate their usefulness. A problem that has drawn considerable attention since the last edition is the association ofdesiccated carbon dioxide absorbent and carbon monoxide formation. The mechanism of the desiccation has not yet been well elucidated.We have looked at gas flows and how it would be possible for absorbent to become desiccated either
from a continuous fresh gas flow or during an anesthetic in the chapter on circle systems. Hopefully this area will continue to be investigated. We have followed our previous policy of not including equipment that is not currently manufactured or in use. Since the last edition, the Committee on Equipment and Facilities of the American Society of Anesthesiologists has published guidelines for anesthesia machine obsolescence.These are given in Chapter 5.We have excluded most equipment that would be considered obsolete by
these criteria. For devices that have a short use span, we have tried to include only those that were available
at the time this text was written. We apologize that there are subjects that could rightfully have been included in this text but were not. The entire book was written by the two authors and it was not possible to include everything. Hopefully others will step up to the plate and produce texts covering subjects we did not include.
We sincerely hope that this text will be useful to experienced anesthesia providers as well as anesthesia residents and student nurse anesthetists. Hopefully they will experience some of the rewards that come from understanding and using both new and familiar equipment that we have enjoyed during the thirty seven years of writing this book. Unfortunately this will be the last edition that we will personally write.We would like to challenge and encourage, others to take up where we have left off.We would be happy to help future authors in any way we can. While it entails a tremendous amount of work, the rewards are priceless.
Susan E. Dorsch, MD
SECTION I: GAS SUPPLY AND DISTRIBUTION SYSTEMS
SECTION II: ANESTHESIA MACHINES AND BREATHING SYSTEMS
CHAPTER 8 Mapleson Breathing Systems 209
SECTION III: AIRWAY EQUIPMENT
SECTION IV: MONITORING DEVICES
SECTION V: EQUIPMENT RELATED TO ENVIRONMENTAL SITUATIONS
SECTION VI: EQUIPMENT CARE
