Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo

A nurse carries a portable oxygen tank in a hospital room.
Figure 18.1 The respiratory system and cardiovascular system together form the cardiopulmonary system. Nurses support patients' respiratory needs in many ways, including by providing them with oxygen, as this critical care nurse is doing for a patient with COVID-19. (credit: "Navy Medical Team Suports Louisiana Hospital" by Mass Communication Specialist 2nd Class Michael H. Lehman/Flickr, Public Domain)

Basic life support training uses the first three letters of the alphabet to quickly refer to the most crucial lifesaving actions for a patient who suffers an arrest situation: assessment of the patient’s airway, breathing, and circulation. Until a few years ago, these were referred to as they appear alphabetically—A-B-C. The 2010 American Heart Association (AHA) guidelines changed the order to reflect circulation as the first response, followed by airway and breathing, so it is now C-A-B (AHA, 2020).

In either order, the respiratory system is associated with two-thirds of the immediate and emergent lifesaving response recommended for cardiac and/or respiratory arrests, which suggests its importance. The cardiovascular system is also critical because it is the adequacy of the heart’s pumping action and vascular circulation that delivers oxygen (O2) and other nutrients. Without adequate perfusion, all body systems and components are at risk for significant compromise and ultimately cell death. Consequently, the first three letters of the alphabet are certainly appropriate as quick and recognizable identifiers of the most necessary immediate lifesaving measures to take in hopes of patient survival.

Citation/Attribution

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at https://openstax.org/books/clinical-nursing-skills/pages/1-introduction
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at https://openstax.org/books/clinical-nursing-skills/pages/1-introduction
Citation information

© Jun 12, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.