Article Text

Download PDFPDF
Mammals (other)
Severe intraoperative hypoxaemia in a horse due to failure of an oxygen concentrator and auxiliary oxygen supply
  1. Josephine Kropf1 and
  2. J. M. Lynne Hughes2
  1. 1 Department of Anaesthesia, University of Glasgow School of Veterinary Medicine, Glasgow, UK
  2. 2 Department of Anaesthesia, University College Dublin College of Agriculture Food Science and Veterinary Medicine, Dublin, Ireland
  1. Correspondence to Josephine Kropf; josephine.kropf{at}


A horse with acute colic underwent exploratory laparotomy. Following anaesthetic induction, the inspired fraction of oxygen (FiO2) was found to be 0.23 and severe hypoxaemia (PaO2: 4.12 kPa [30.9 mmHg]) was detected. The terminal oxygen outlet was delivering mostly pressurised room air due to a mechanical fault within the oxygen concentrator, with subsequent failure of the auxiliary oxygen manifold. The oxygen supply in the operating room was switched to a cylinder (FiO2: 0.95) but PaO2 increased to only 12.3 kPa [92.3 mmHg], indicating probable ventilation/perfusion mismatch. Anaesthetic recovery was uneventful, but signs of abdominal pain returned four days later. A second laparotomy revealed perforation of the jejunum and generalised peritonitis, and the horse was euthanased. Failure of both an oxygen concentrator and the backup supply is rare but potentially disastrous. A thorough preanaesthetic equipment check, including the FiO2, and detailed knowledge of all equipment components are essential for the anaesthetist.

  • anaesthesia
  • horses
  • clinical
View Full Text

Statistics from


  • Contributors JK: case collection and preparation of manuscript. LH: preparation of manuscript and critical revision.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional data are available.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.