Abstract:
Major surgery is followed by a long period of convalescence. However this recovery period
is not well defined and tools for its measurement and assessment are lacking. This thesis
describes the concept of Post Operative Fatigue as a clinically relevant outcome measure for
assessment of convalescence. It will analyse the existing literature and describe a clinically
relevant measurement tool for assessment of POF and will provide a clinically appropriate
definition for this topic. It will demonstrate that POF is as a result of interaction between
psychological and biological variables which are as a direct result of the perioperative care
and operation itself. It will also be hypothesised that inflammatory mediators may also play
an important role in the development of POF. These mediators stimulate the vagus nerve,
which through its central connection leads to behavioural changes in subjects. Chapter 2 will
analyse evidence available which may address the numerous factors which contribute to the
development of POF. This leads to the introduction of Enhanced Recovery After Surgery
(ERAS) care pathways. Chapter 3 will review a prospective study which demonstrates that
ERAS is an effective measure to improve outcomes following major colonic surgery.
Chapter 4 will utilize a recently validated multi-dimensional measurement tool called the
Identity-Consequence Fatigue Scale to measure POF in a group of patients undergoing
surgery within a conventional care plan compared to a group within a structured ERAS
program. It will be shown that ERAS can lead to detectable changes in POF in patients
undergoing major colonic surgery. Lastly, it will be demonstrated through a randomised
controlled trial that preoperative dexamethasone suppresses the post operative inflammatory
response following surgery. It will be subsequently demonstrated that there is a direct
correlation between post operative peritoneal IL-6 and POF and reduction in peritoneal IL-6
levels leads to a detectable reduction in POF.
Conclusion: POF should be considered an important outcome measure. POF has a
multifactorial aetiology and hence it can be modified by multimodal interventions.
Inflammatory mediators also play a role in the development of POF and their influence can
be modified by preoperative steroids.