Public Defence: Torkjell Nøstdal Torkjell Nøstdal at Institute of Clinical Medicine will be defending the thesis “Postoperative Fatigue; Assessment and Clinical Implications” for the degree of PhD (Philosophiae Doctor).

Image may contain: Top, Face, Facial expression, Forehead, Head.

Photo: Private

Trial Lecture – time and place

See Trial Lecture.

Adjudication committee

  • First opponent: Professor Henrik Kehlet, University of Copenhagen
  • Second opponent: Professor Line Merete Oldervoll, NTNU
  • Third member and chair of the evaluation committee: Professor Egil Johnson, University of Oslo

Chair of the Defence

Professor II Vegard Dahl, University of Oslo

Principal Supervisor

Professor II Johan Ræder, University of Oslo


Fatigue is common in the general population (10-20%), but is markedly higher within a wide range of diseases and conditions. Treatment of a disease may also induce or augment fatigue. Despite the high prevalence of fatigue, we know little of its cause. Possibly, fatigue may be a normal, biologically sound response; signalling a need to rest.

After day-surgery, fatigue may be a major problem and an important determinant of time to complete recovery. Postoperative fatigue (POF) may impede recovery with an influence similar to that of postoperative pain.

Pharmacological agents are also thought to cause fatigue. Propofol and desflurane are among the most widely used agents in modern anaesthesia. A previous study described significantly more POF during the first postoperative week in patients receiving a propofol-based anaesthesia compared to patients receiving a desflurane-based anaesthesia.

The primary aim of this project was to study whether choice of anaesthesia would result in differences in fatigue. We performed a randomised study in 123 patients undergoing laparoscopic cholecystectomy, comparing POF after anaesthesia with propofol or desflurane. We found no difference in postoperative fatigue between the two anaesthetic regimens. Choice of anaesthetic regimen may be made without consideration of a potential impact on fatigue.

The project also included a validation of three commonly used questionnaires considered suitable for assessment of POF. The POF scales all proved to be valid for research on POF and surgical recovery. We could also present a 10-item, abridged version of the most extensive, 31-item scale.

The clinical impact of fatigue is not fully established. Thus, the identification of a cut-off point for clinically significant fatigue became an integrated part of the project. We identified the cut-off point for clinically significant fatigue near the centre of the three questionnaires’ respective score range.

Additional information

Contact the research support staff.

Published Jan. 20, 2020 1:03 PM - Last modified Feb. 26, 2020 9:37 PM