Though age is directly correlated with frailty, it is not an inevitable component. Multiple frailty assessment tools are being created on the basis of clinical judgement which are subjective and time- consuming  Further, none of them is a gold standard for identifying frailty. Most of the frailty indexes require patient cooperation and ability to walk which might not be possible in a subset of frail patients.  Hence, an objective, quick tool is required to identify frailty in perioperative settings. Sarcopenia is a functional marker for frailty that can be quantified objectively. Computed tomography is an objective but expensive and resource-intensive tool for assessing sarcopenia by measuring psoas muscle area. Further, it exposes patients to radiations.

Bedside ultrasound is a quick, bedside tool that can determine sarcopenia in perioperative settings without any harmful effects. It can be used to identify frail population preoperatively, and hence, has a potential in risk – stratification of patients. 

Previous observational studies are done in western population undergoing heterogenous surgeries to discriminate between frail and not-frail patients using ultrasound. However, the type of surgery can have a confounding impact on the postoperative outcome. Further no studies are conducted on Indian population. Hence, we propose to conduct a prospective, single center, observational study in Indian patients undergoing major abdominal surgery to determine if ultrasound guided quadriceps thickness can be used as a sensitive tool in differentiating between frail and not- frail patients, thereby predicting adverse postoperative outcomes.