Respiratory Effects of Perioperative Oxygen During General Anaesthesia

Perioperative Oxygen Fraction - Effects on the PaO2/FiO2-Index During Laparotomy

Aim: To investigate the effect of high intra- and postoperative oxygen concentration (80%, as opposed to normally 30%) on pulmonary gas exchange and other pulmonary complications after abdominal surgery.

Background: Previous studies have shown possible beneficial effects of high perioperative oxygen concentration on surgical wound infection and healing, but all pulmonary effects are not clarified. Change in perioperative PaO2/FiO2 and shunt-fraction, measured by a gas rebreathing technique, can describe pulmonary oxygenation. This could add knowledge to the pulmonary effects of high vs. normal oxygen concentration.

Primary hypothesis of study: Perioperative use of a 80% oxygen concentration reduces the PaO2/FiO2-index compared to 30% oxygen.

Inclusion Criteria:

• Age 18 years or older
• Laparatomy, elective

Exclusion Criteria:

• Inability to give informed consent
• Chemotherapy within 3 months
• Other surgery within 30 days(except surgery in local anaesthesia)
• Inability to keep oxygen saturation above 90% without supplemental oxygen (measured preoperatively by pulse oximetry)