Conditions: Anaesthesia
Keywords: Xenon in Anaesthesia
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 102
Healthy volunteers: no

Brief summary:
The purpose of this study is to evaluate the quantity of propofol administered with Xenon in two inspiratory concentrations, to maintain comparable depth of anaesthesia during the maintenance period of general anaesthesia.

Detailed description:
The inert or "noble" gas Xenon has anaesthetic properties that have been recognized 50 years ago. Several preclinical studies and investigations using xenon as an inhalational anaesthetic in humans were performed and reported that this gas has many properties of the ideal anaesthetic agent. Moreover, it is known that when xenon is combined with volatile anaesthetics or opioids, the required doses of those substances are reduced, resulting in a lower incidence of side effects. Patients could benefit from the administration of xenon if this inspired concentration would result in reduced doses of co-administered drugs.

This trial should allow evaluating the propofol consumption required in combination with xenon administered in inspiratory concentrations of 50% and 70% to maintain comparable depth of general anaesthesia as total i.v. anaesthesia, in ASA III patients presenting increased risk of perioperative cardiac complications and undergoing laparotomy or orthopaedic surgery.

Arms:
arm 1: Xenon 50% (45%-55%) in Oxygen (45%-55%), arm 2: Xenon 70% (65%-75%) in Oxygen (25%-35%) arm 3: Medical Air in Oxygen (45%-55%)

Interventions: intervention 1: Xenon intervention 2: Xenon intervention 3: Medical Air in Oxygen
Intervention descriptions: intervention 1: Maintenance of anaesthesia obtained with Xenon 50% and propofol infusion adjusted to depth of anaesthesia. intervention 2: Maintenance of anaesthesia obtained with Xenon 70% and propofol infusion adjusted to depth of anaesthesia. intervention 3: Maintenance of anaesthesia obtained with propofol infusion adjusted to depth of anaesthesia.

Protocol document: