Perioperative Nutritional Support for Older Colorectal Surgical Patients

Background
Older adults undergoing colorectal surgery experience high levels of mortality. Malnutrition, low muscle quality, or sarcopenia, and reduced physiological reserve are common but are inconsistently identified and managed across the perioperative pathway. Although screening tools are recommended, uncertainty remains regarding which patients are at risk of adverse outcomes and which nutritional interventions are effective in clinical care.
Aims
This thesis investigated how malnutrition and sarcopenia are identified and managed in older adults undergoing elective or emergency colorectal surgery to evaluate practical strategies to improve nutritional support.
Methods
A mixed-methods programme was undertaken within a pragmatic epistemological stance. Quantitative studies included a retrospective observational study examining CT-defined psoas muscle density, its relationship with MUST scores, and 60-day mortality in older emergency colorectal surgical patients. A clinical audit assessed compliance to screening and intervention guidelines. Qualitative data were generated through a service evaluation survey exploring barriers to prescribing oral nutritional supplements. A rapid literature review synthesised current evidence to guide supplement prescribing in practice. A feasibility study evaluated the acceptability and adherence to a novel essential amino acid supplement in elective colorectal cancer patients and emergency laparotomy patients.
Results
Low CT-defined muscle quality and higher MUST scores independently identified increased mortality risk, providing a holistic view of physiological vulnerability. Despite high compliance with malnutrition risk screening, substantial gaps existed between risk identification and support. Clinicians reported varying confidence and inconsistent prescribing practice, influenced by a lack of training. Evidence synthesis supports protein-rich supplementation to achieve recommended daily intakes for older adults. The feasibility study demonstrated that amino acid supplementation was acceptable for elective patients and did not suppress appetite.
Conclusion
This thesis demonstrates that integrating muscle quality assessment with nutritional screening may enhance risk stratification in older colorectal surgical patients. Addressing implementation barriers and adopting patient centred strategies may improve perioperative care.