Frailty and Sarcopenia Outcomes in Emergency General Surgery

Overview

1. A retrospective scoping cohort review of adult patients undergoing emergency laparotomy/laparoscopy for acute gastrointestinal (GI) pathology who have had a CT scan of the abdomen(+/- pelvis). CT measured sarcopenia would be compared with clinical outcomes, 30-day and 1-year mortality. 2. A prospective observational cohort study and bio-banking exercise of routinely collected clinical data, in a cohort of patient undergoing emergency laparotomy/laparoscopy or conservative treatment for an otherwise operable pathology. An interrogation of CT measured sarcopenia and a validated clinical frailty score would be analysed against clinical outcomes, 30-day and 1-year mortality. The investigators aim to research the association and predictive advantage of combining subjectively measured frailty, objectively measured CT sarcopenia and other risk predicting tools used in every day surgical practice and surgical outcomes (mortality and morbidity) in a cohort of acute surgical patients undergoing surgery or conservative treatment.

Frailty has a significant impact on surgical outcomes. It is an independent risk factor for adverse outcomes following surgery including complications, length of stay, inability to return home and mortality. Frailty is a physiological decline across multiple body systems accumulating in loss of reserves and increased vulnerability to stressors. Sarcopenia, loss of muscle mass or progressive reduction in muscle mass, is one of the central physiological manifestations of frailty resulting in weight loss, weakness and exhaustion. Frailty has both a strong correlation with age as well as significant overlap with disability and co-morbidity. Further factors strongly influencing outcome, 30 day and mortality have been described including polypharmacy, Charlson co-morbidity index, age, not independently mobile, emergency admission and falls. It has been recognised that poor outcomes are multimodal relating to the interplay of co-morbidities, physical functioning and nutrition. Assessing frailty can be completed using simple questionnaire tools, as well as more complex assessment of co-morbidity, functional status, and disability. There is good evidence the simple tools can be as accurate as formal geriatric assessments. As sarcopenia relates directly to many manifestations of frailty it can be used as a surrogate marker. One of the favoured ways for diagnosing sarcopenia is using CT morphometric biological markers. This uses an axial image at the level of the 3rd lumbar vertebra (L3) to assess the total or cross-sectional volume of the psoas muscle, giving rise to indices measuring muscle mass, visceral adipose tissue and subcutaneous adipose tissue. Major abdominal emergency surgery is a high-risk procedure with ongoing audit and outcome monitoring. Currently data collection for UK National Emergency Laparotomy Audit (NELA) is in its fourth year with annual reports into the management and outcomes of emergency laparotomies. Observation and audit of these outcomes remain central to improving service and healthcare both regionally and nationally. Furthermore, this group of patients is not well represented in research and is one of the most understudied surgical cohorts that exist. This is especially the case for patients presenting with an acute surgical diagnosis and are deemed unable to withstand the stress of surgery, and hence pursue a conservative or radiological treatment option. With our ageing, co-morbid population this is becoming increasing common. The diagnosis of frailty and sarcopenia are a significant measurable and modifiable risk factor that impacts on perioperative surgical care, healthcare provider and patient decision-making and most importantly long and short term outcomes. This urgently requires further audit and study. Work package one (WP1): Retrospective scoping cohort study in acute general surgery Patient identification The number of patients recruited from each participating hospital will be proportionate to the total number of cases, in accordance with relative annual case volumes (as reported by NELA - in the case of less than 100% case capture, the theoretical 100% case number will be used). This will provide a representative sample of the recruiting region's population. The most recent laparotomy cases with 1-year follow-up mortality data available will be included at the time of study activation. Data collection over a predicted six week period will be undertaken or until the sample size is reached. Retrospective collection of routinely recorded clinical data will be performed (See appendix data collection tool). This includes, but is not restricted to \[a\] routine clinical variables: patient characteristics, demographic, pathological and physiological variables will be captured in line with NELA data, alongside confounding factors associated with frailty and sarcopenia. Protocol for measuring muscle radiation attenuation Inclusion: Retrievable CT abdomen/pelvis on an electronic NHS PACS system. CT can be non-contrast or with contrast, supine or prone but must be of sufficient quality for the sarcopenia CT analyses software to handle (Slico-matic™, TomoVision, Magog, Canada ). Exclusion: CT-scans with large radiation artefacts or with missing parts of muscle tissue on the ventral, dorsal, or both lateral edges of the scan preventing sarcopenia assessment. Patients meeting inclusion criteria will have their CT extracted and reviewed by a trained independent party. This may through an allocated representative at the base hospital or the CT can be extracted and sent in a fully anonymised format to the central unit for sarcopenia assessment. CT scans obtained via a PACS system can up transferred through secure inter-hospital PACS transfer. Those with non-compatible systems can either be uploaded via CD or analysed at the data collection site. The outcome of the assessment for sarcopenia will define whether a patient is considered to have sarcopenia. Participants can be identified primarily from the NELA database with confirmation of GI pathology on the radiological report. This can be cross reference against admission logs, acute surgery admission databases, theatre logs for emergency surgery and NELA databases to maximise case capture. Once patients are confirmed to meet the inclusion criteria their data can be gathered into a data collection tool. The CT scan will be extracted and sent for analysis. All patients meeting inclusion criteria will be identified by the lead researcher in each centre. Frailty scores are already part of standard acute admission clerking proformas in many of the hospitals across the region; as such the researcher's role will be ensure appropriate and complete data capture from existing clinical information sources, but no additional intervention or questioning of patients beyond current standard of care will be required. Patients will be collected across a set time scale as listed above. Baseline demographics and disease factors will be collected as per collection proforma attached as supplementary material. The Reported Edmonton Frail Scale (REFS) is collected at time of admission as part of routine clinical assessment for surgical admissions. This is a validated, self-reported patient questionnaire that can categorise the degree of frailty. This information is routinely collected in many acute unit or care of the elderly departments. The REFS will enable a consistent method of collecting this data utilising a rapid and well validated tool. For patients presenting in extremis or unable to complete the score due to an acute state or requirement for prompt treatment, this will be gathered at the next appropriate pre-operative opportunity. Patients unable to complete a REFS given the best opportunity will be excluded, however reasons for exclusion will be recorded.