Frailty for Perioperative Clinicians: A Narrative Review

Daniel I. McIsaac, MD, MPH, FRCPC; David B. MacDonald, MD, FRCPC; Sylvie D. Aucoin, MD, MSc, FRCPC


Anesth Analg. 2020;130(6):1450-1460. 

In This Article

Improving Outcomes for Older Surgical Patients With Frailty

Preoperative frailty assessment provides an opportunity to identify a relatively homogenous and high-risk stratum of the older surgical population; early evidence suggests that the act of assessment and communication of frailty status to the perioperative team could improve outcomes on its own.[53] However, we suggest that frailty assessment most likely represents a first step linking risk stratification to perioperative optimization for high risk older surgical patients, a statement that reflects the underlying multidimensional nature of frailty. In fact, evidence from nonsurgical older populations suggests that prognostic accuracy can be improved by differentiating the major underlying contributors to frailty.[74] Therefore, once frailty has been identified, contributors to frailty (ie, physical performance, nutrition, cognition, and mental health) can be highlighted using simple, validated screening tests (Figure 2). This should allow preoperative clinicians to link assessment to rational, evidence-based optimization strategies and support future research into optimization of older people with frailty before surgery.

Figure 2.

Proposed preoperative screening pathway for routine identification of frailty and underlying causal contributors to guide frailty-focused optimization before surgery (CNST, DASI, PHQ-2, TUGT). (Terms of Use: This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. It is attributed to Daniel McIsaac.) CNST indicates Canadian Nutrition Screening Tool; DASI, Duke Activity Status Index; PHQ-2, two question personal health questionnaire; TUGT, Timed Up and Go Test.

Physical Performance

Surgical stress and postoperative immobility can substantially worsen physical performance in older people with frailty. Older people often experience immobilization after surgery, and when confined to bed rest, even healthy older adults lose 1.5 pounds of muscle mass per week.[75] This combination of preexisting physical vulnerability, surgical stress, and immobility can result in significant disability due to loss of lower limb function.[26] Therefore, identification of physical vulnerability before surgery could help to select individuals who might benefit from interventions to improve physical function, such as exercise prehabilitation.

While many screeners and questionnaires exist to quantify physical performance before surgery, the Duke Activity Status Index (DASI)[76] stands out as feasible and accurate tool. In an international multicenter study, the DASI was found to out-perform cardiopulmonary exercise testing when predicting adverse postoperative events[77] and outperformed the more time-intensive 6-minute walk test when predicting the occurrence of new disability.[78] Therefore, clinicians could consider the DASI as a screener for physical vulnerability among patients with frailty. One issue with the DASI, however, is that it has not been adequately tested in older people with frailty. Therefore, other standard measures of physical performance in older people, such as the timed up and go test, also deserve serious consideration.[79]

Once identified, such individuals may benefit from exercise prehabilitation, which has been shown to decrease complication rates[80,81] and possibly improve functional outcomes.[82,83] While generalizable multicenter randomized trials are still required, preliminary data suggest that people with frailty characteristics may benefit most from exercise before surgery,[84] and systematic reviews suggest that multimodal (ie, aerobic and strength training) exercise, performed at least 3 times per week,[85] for at least 2 weeks before surgery,[86] appears to be the most promising design.


Malnutrition is prevalent in people with frailty (10%–20%)[87,88] as well as in older surgical patients (15%–60%, with higher rates seen in people with gastrointestinal and cancer diagnoses).[89,90] Malnutrition can leave older people vulnerable to physical and physiologic stressors, especially in the setting of surgery. Complications, prolonged length of stay, impaired functional recovery, and delirium are associated with malnutrition.[89,91,92] Therefore, addressing macro- and micronutrient deficits represents a promising means of optimizing the older person with frailty before surgery.

Similar to screening for physical performance, many tools are available to screen for malnutrition. These include calculation of body mass index, history of unintentional weight loss, or more specific nutritional screeners, such as the Canadian Nutrition Screening Tool (CNST)[93] or Mini Nutritional Assessment.[94] The CNST is a simple 2 question screener with good sensitivity (92%), specificity (75%), and interrater agreement (kappa = 0.88).[93]

While large studies of nutritional supplementation before surgery have not been performed in older people with frailty, protein supplementation has been a key component of several successful multimodal prehabilitation programs.[80–82,95] For people performing exercise prehabilitation, meeting protein requirements is especially important as these individuals will be attempting to address preexisting deficits while increasing demand through newly increased activity levels. Current perioperative guidelines recommend 1.5 g/kg/d (based on ideal body weight),[90] and it may be advisable to address malnutrition before commencing exercise therapy. Identification of iron deficiency anemia and treatment has also been included in prehabilitation programs and could be considered as well.[81]

Cognitive Dysfunction

Even among older people with frailty, clinically apparent dementia is uncommon.[96] However, mild neurocognitive dysfunction is prevalent and could contribute to the development of postoperative delirium and other adverse outcomes. The Mini-Cog test is currently recommended by best practice guidelines from the American College of Surgeons and American Geriatrics Society and can be considered as a cognitive screener before surgery.[48]

Once identified, the best available evidence suggests that environmental optimization and avoidance of delirium triggers can be used to reduce delirium after surgery.[97] The Hospital Elder Life Program[98] represents a bundled approach to delirium prevention (orientation, nutrition, mobilization) that is associated with lower delirium rates in surgical patients.[99] The role of cognitive prehabilitation, while promising, requires further study.[100,101]

Mental Health

Anxiety and depression are common in older surgical patients and can relate to underlying psychosocial stressors, the impact of the surgical diagnosis, or other organic causes of depression. Given the high absolute risk of nonhome discharge among older people with frailty, identifying underlying mental health issues and psychosocial stressors could help to pinpoint individuals who will have more complex discharge needs, reduced support for going home, or both. The 2 question Personal Health Questionnaire (PHQ-2) is 86% sensitive and 78% specific for identifying individuals with major depression and could be considered by preoperative clinicians as a screening tool for depression.[56] Unfortunately, to date, little interventional data are available to suggest specific strategies to intervene in this regard. However, well-designed multidisciplinary geriatric care pathways that include preadmission discharge planning show promise for decreasing adverse events and resource use among high-risk older patients.[102,103]