Cardiac arrest

Introduction

• The success rate of CPR is disappointingly low.
• One retrospective investigation of intensive care patients at Colorado State University found that only 4.1% of the dogs and 9.6% of the cats which suffered cardiopulmonary arrest survived to discharge.
• In contrast, animals which suffer respiratory arrest alone are much more likely to be successfully resuscitated .
• Anesthetized patients suffering CPA may have improved outcome as they are intubated , breathing 100% oxygen, and have a peripheral catheter in place. The incidence of anesthesia-induced cardiopulmonary arrest has been reported to be as high as 35/10,000. Anesthesia-related CPA may be due to equipment failure, respiratory or cardiovascular problems, or human error.
• Anesthetic overdose (absolute or relative), is also an important cause of CPA associated with anesthesia.
• Four factors are generally believed to be related to poor outcome of CPA:
  • Long arrest time prior to initiation of CPR.
  • Prolonged ventricular fibrillation .
  • Inadequate coronary or cerebral perfusion during CPR.
  • Pre-existing disease.
• Successful outcomes depend upon:
  • Prompt recognition of developing problems.
  • Rapid diagnosis of the underlying cause.
  • Taking appropriate measures to correct the problem quickly.
  • Monitoring of patient during anesthesia to avert accidents during and after anesthesia.
• Main requirements during anesthesia:
  • Adequate delivery of oxygen to tissues (3-5 ml/kg/min).
  • Removal of waste products from tissues.
  • Failure to achieve the above can result in serious complications particularly tissue hypoxia and cell death.
  • Main requirement of the circulation is to deliver an adequate supply of well oxygenated blood to the tissues. Adequate perfusion of tissue is as important as oxygenation of the blood.
  • Mean blood pressure should be maintained above 70 mmHg.

Sources

Publications

Refereed papers

• Recent references from PubMed.

Other sources of information

• Hall L W & Taylor P M (1994) Eds Anesthesia of the Cat. London: Bailliere Tindall. pp 249-266, 270-273, 274-309. ISBN 0 7020 1665 9
• Bedford P G C (1991) Small Animal Anesthesia, The Increased Risk Patient. London: Bailliere Tindall. p 92- 132. ISBN 0 7020 1501 6.
• Richards D L S (1989) Anesthetic accidents and emergencies. In Manual of Anesthesia for Small Animal Practice. Ed: A D R Hilbery. Cheltenham: British Small Animal Veterinary Association. pp 95-99. ISBN 0 905214 09 9.
• Hall L W (1982) Relaxant drugs in small animal anesthesia. In Proceedings of the Association of Veterinary Anesthetists of Great Britain and Ireland Supplement to 10 , pp 144-155.