Fink effect
Effect of anesthesia
title: "Fink effect" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["anesthesia", "diffusion"] description: "Effect of anesthesia" topic_path: "general/anesthesia" source: "https://en.wikipedia.org/wiki/Fink_effect" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Effect of anesthesia ::
The Fink effect, also known as "diffusion anoxia", "diffusion hypoxia", | title = Understanding Anaesthesiology | author = S. Ahanatha Pillai | publisher = Jaypee Brothers Publishers | year = 2007 | isbn = 978-81-8448-169-3 | page = 101 | url = https://books.google.com/books?id=rCvEJibQstcC&q=Fink-effect%20%20hypoxia&pg=PA101 or the "second gas effect", | title = Anaesthesia and Intensive Care A–Z: An Encyclopedia of Principles and Practice | author1 = Steven M. Yentis | author2 = Nicholas P. Hirsch | author3 = Gary B. Smith | publisher = Elsevier Health Sciences | year = 2009 | isbn = 978-0-443-06785-3 | url = https://books.google.com/books?id=kxxDYTV7DqUC&q=%22third%20gas%20effect%22%20fink&pg=PT534 is a factor that influences the pO2 (partial pressure of oxygen) within the pulmonary alveoli. When water-soluble gases such as anesthetic agent N2O (nitrous oxide) are breathed in large quantities they can be dissolved in body fluids rapidly. This leads to a temporary increase in both the concentrations and partial pressures of oxygen and carbon dioxide in the alveoli.
The effect is named after Bernard Raymond Fink (1914–2000), whose 1955 paper first explained it. | title = Notable Names in Anaesthesia | author = J. Roger Maltby | publisher = Royal Society of Medicine Press | year = 2002 | isbn = 978-1-85315-512-3 | page = 63 | url = https://books.google.com/books?id=Yc4_uLDkzgAC&q=Fink-effect%20%20nitrous&pg=PA63 | author = Bernard R. Fink | author-link = Bernard Raymond Fink | title = Diffusion Anoxia | journal = Anesthesiology | year = 1955 | volume = 16 | issue = 4 | pages = 511–519 | doi = 10.1097/00000542-195507000-00007 | pmid = 13238868 | doi-access = free When a patient is recovering from N2O anaesthesia, large quantities of this gas cross from the blood into the alveoli (down its concentration gradient) and so for a short period of time, the O2 and CO2 in the alveoli are diluted by this gas. A sufficiently large decrease in the partial pressure of oxygen leads to hypoxia, especially if the patient hypoventilates (which allows more time for evolving nitrous to dilute alveolar oxygen each breath). | author = S. EINARSSON | title = Nitrous Oxide Elimination and Diffusion Hypoxia During Normo- and Hypoventilation | journal = British Journal of Anaesthesia | year = 1993 | volume = 71 | issue = 2 | pages = 189–93 | doi = 10.1093/bja/71.2.189 | pmid = 8123390 | doi-access = free Nonetheless, this effect only lasts a couple of minutes and hypoxia can be avoided by increasing the fractional inspired oxygen concentration when recovering from N2O administration. | title = Nunn's Applied Respiratory Physiology | author1 = Andrew B. Lumb | author2 = John F. Nunn | edition = 6th | publisher = Elsevier/Butterworth Heinemann | year = 2005 | isbn = 978-0-7506-8791-1 | page = 169 | url = https://books.google.com/books?id=29hqAAAAMAAJ&q=Fink-effect++intitle:Respiratory+intitle:Physiology+inauthor:Nunn It is for this reason that Entonox, a 50:50 gaseous mixture of nitrous oxide and oxygen, is suitable for use by para-medical staff such as ambulance officers: it provides sufficient nitrous oxide for pain relief with sufficient oxygen to avoid hypoxia. | title = Entonox | url = http://www.frca.co.uk/article.aspx?articleid=100364 | website = AnaesthesiaUK (www.frca.co.uk) | access-date = 27 February 2017 | date = 26 January 2009 | url-status = live | archive-url = https://web.archive.org/web/20071031101605/http://www.frca.co.uk/article.aspx?articleid=100364 | archive-date = 31 October 2007 | publisher = Joint Royal Colleges Ambulance Liaison Committee | title = UK Ambulance Service Clinical Practice Guidelines (2006) | date = October 2006 | access-date = 27 February 2018 | url = http://www2.warwick.ac.uk/fac/med/research/hsri/emergencycare/prehospitalcare/jrcalcstakeholderwebsite/guidelines/clinical_guidelines_2006.pdf | author1 = Joanne D. Fisher | author2 = Simon N. Brown | author3 = Matthew W. Cooke | isbn = 1-84690-060-3 | url-status = live | archive-url = https://web.archive.org/web/20110605073519/http://www2.warwick.ac.uk/fac/med/research/hsri/emergencycare/prehospitalcare/jrcalcstakeholderwebsite/guidelines/clinical_guidelines_2006.pdf | archive-date = 5 June 2011
References
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