Post-Operative Creatinine Changes In Patients With Pre-Existing Renal Impairment After Low-Flow Isoflurane Or Sevoflurane: A Randomised Clinical Trial

Study Protocol Post-Operative Creatinine Changes In Patients With Pre-Existing Renal Impairment After Low-Flow Isoflurane Or Sevoflurane: A Randomised Clinical Trial

Introduction

Sevoflurane is a volatile anaesthetic agent available for clinical use in most countries including Australia, the United States, the United Kingdom, and Canada. Since the first clinical use of sevoflurane in Japan during the 1980s, millions of anaesthetics have been given with sevoflurane. Sevoflurane has a number of advantages over other agents for general anaesthesia, particularly isoflurane. The benefits to patients and the environment include:

• A lower blood and tissue solubility allows patients to wake up faster after anaesthesia 1, 2.
• The lower blood solubility allows faster titration during surgery.
• Heart rate is more stable during increases in inspired concentration.
• Airway resistance is lower than with other volatile agents.
• A pleasant smell allows gas induction
• There is less nausea and vomiting than with isoflurane
• It is a fluorocarbon rather than a chlorofluorocarbon and does not worsen the atmospheric ozone hole.

The most important concern about sevoflurane is its effect on renal function due to breakdown products. When sevoflurane is exposed to the carbon dioxide absorbents soda lime and baralyme a vinyl breakdown product called Compound-A is formed. High dose exposure to Compound-A alters kidney histology in rats. Some, but not all, studies have found that Compound-A produces increases urinary secretion of renal tubule enzymes in humans. The clinical importance of enzyme secretion is unclear.