FRAILTY SCORE INDEX IN ANAESTHESIA

Long Answer - MD Anaesthesia Examination

INTRODUCTION AND DEFINITION

Sources: Miller's Anesthesia 10e, Barash's Clinical Anesthesia 9e, Current Surgical Therapy 14e

PATHOPHYSIOLOGY AND MODELS

1. The Frailty Phenotype (Fried Model)

• 0 criteria: Robust / Non-frail
• 1-2 criteria: Pre-frail
• ≥3 criteria: Frail

2. The Deficit Accumulation Model (Rockwood Model)

Frailty Index = Number of positive deficits / Total deficits assessed

VALIDATED FRAILTY ASSESSMENT INSTRUMENTS

A. Clinical Frailty Scale (CFS)

• Takes <2 minutes to administer
• No special equipment or extra space required
• Web-based training modules available for standardised application
• In direct comparison with the modified Fried Index, clinicians found it easier to use, more feasible in clinical settings, and quicker (<1 min vs 5 min)
• Predicts postoperative mortality and non-home discharge
• In systematic review and meta-analysis, the CFS had the strongest accuracy and feasibility among available scales

B. Fried Phenotype (Modified Frailty Phenotype)

C. Edmonton Frail Scale (EFS)

1. Clock drawing test (cognition)
2. Timed Up-And-Go (TUG) test (functional performance)
3. General health status (two questions)
4. Functional independence (ADLs)
5. Social support
6. Medication use (polypharmacy; ≥5 medications)
7. Nutrition (weight loss)
8. Mood (depression screening)
9. Continence
10. Functional performance (TUG)
11. Nine standardized questions

• 0-5: Not frail
• 6-7: Vulnerable
• 8-9: Mild frailty
• 10-11: Moderate frailty
• 12-17: Severe frailty

D. FRAIL Scale

• 0: Robust
• 1-2: Pre-frail
• 3-5: Frail

E. Modified Frailty Index (mFI / mFI-5)

• Major postoperative complications (OR 1.58)
• Prolonged length of stay (OR 1.89)
• Discharge to higher level of care (OR 2.29)
• 30-day mortality (OR 2.05 per 0.1 increase in frailty score)

F. Robinson's Surgical Frailty Definitions

• Mini-Cog score ≤3
• Serum albumin ≤30 g/L
• One or more falls in the prior 6 months
• Haematocrit <35%

• Timed Up-And-Go (TUG) ≥15 seconds
• Activity of daily living (ADL) dependence
• Charlson Comorbidity Index score ≥3

G. Risk Analysis Index (RAI)

COMPARISON TABLE OF FRAILTY TOOLS (Barash 9e, Table 34-1)

PERIOPERATIVE SIGNIFICANCE OF FRAILTY

Association with Adverse Outcomes

• Surgical complications: Frailty is independently associated with higher postoperative complication rates across general surgery, orthopaedic surgery, cardiac surgery, and spine surgery.
• Postoperative delirium: Frailty (especially assessed by Fried Phenotype) is the strongest predictor; incidence of delirium 5-50% in older surgical patients.
• Prolonged hospital stay: Frail patients have significantly longer length of stay.
• Non-home discharge: CFS ≥4 independently predicts discharge to skilled nursing/assisted-living facilities.
• Mortality: 7.7% one-year mortality in frail patients undergoing elective orthopaedic surgery. Degree of frailty independently and dose-dependently predicts readmission or death.
• Frailty augments other risk scores: Adds prognostic value beyond ASA score, RCRI, and Eagle's Cardiac Risk Index.

Current Practice Gaps

1. Focus on cardiorespiratory evaluation
2. Need for more training
3. Absence of formal guidelines for evidence-based frailty assessment
4. Time constraints in busy clinical settings

FRAILTY IN ANAESTHETIC PRACTICE

Preoperative Assessment

• Frailty screening should be incorporated into the preoperative assessment of all patients aged ≥65 years, and younger patients with clinical suspicion of reduced physiologic reserve.
• The CFS is recommended as the most feasible clinical approach: it takes <1 minute, requires no equipment, and has comparable accuracy to longer tools.
• Comprehensive Geriatric Assessment (CGA) - the gold standard - examines: burden of comorbidity, polypharmacy, physical function, psychological status, nutrition, delirium risk, and social support.
• CGA is more powerful than ASA score alone for predicting perioperative risk in older patients (mean age 78 years).

Anaesthetic Implications of Frailty

1. Pharmacokinetics/Pharmacodynamics: Frail patients have reduced muscle mass (sarcopenia), altered body composition, decreased hepatic and renal blood flow - leading to unpredictable drug distribution and prolonged drug effect.
2. Airway management: Reduced physiologic reserve limits apnoea tolerance; careful preoxygenation is essential.
3. Haemodynamic instability: Reduced cardiovascular reserve increases sensitivity to anaesthetic agents and volume changes.
4. Postoperative delirium prevention: Frail patients at high risk; prefer shorter-acting agents, minimise benzodiazepines, use multimodal analgesia.
5. Hypothermia: Reduced muscle mass and subcutaneous fat increase risk.
6. Pain management: Altered pharmacodynamics; opioids require dose reduction.
7. Regional vs general anaesthesia: No definitive evidence that one technique is superior in frail patients, but regional techniques may reduce physiologic stress.
8. Informed consent and goals of care: Frailty identified preoperatively allows for informed shared decision-making and realistic outcome counselling.

Prehabilitation

1. Nutritional assessment and optimisation (increase protein intake)
2. Physical exercise and optimisation of functional status
3. Lifestyle modification (smoking cessation, alcohol reduction)
4. Psychological preparation and stress management

OBJECTIVE/RADIOGRAPHIC MARKERS OF FRAILTY

• Psoas muscle area on CT (marker of sarcopenia)
• Preoperative ultrasound measurement of quadriceps depth - a simple, non-invasive bedside tool for identifying high-risk elderly patients
• These opportunistic imaging-based assessments could help operationalise frailty screening using imaging already obtained for surgical planning.

SUMMARY

CLINICAL FRAILTY SCALE (CFS)

Cited exclusively from Anaesthesia Textbooks

DEFINITION AND CONCEPTUAL BASIS

"Frailty, which is defined as a state of increased vulnerability to physiologic stressors, is associated with adverse health outcomes after medical and surgical interventions and limited life expectancy."

- Miller's Anesthesia, 10e, p. 3857

1. The Frailty Phenotype (Fried et al.) - based on five physical traits
2. The Deficit Accumulation Model (Rockwood et al.) - based on 92 signs, symptoms, functional impairments, and laboratory abnormalities proportionally weighted into a Frailty Index

"The accumulating deficit model was used to develop the nine-level Clinical Frailty Scale (CFS), where frailty is defined by a CFS score ≥4."

- Miller's Anesthesia, 10e, p. 3858

THE CLINICAL FRAILTY SCALE (CFS)

Box 68.1 - Clinical Frailty Scale

Frailty is defined by CFS score ≥ 4

CFS vs. OTHER FRAILTY TOOLS - ANAESTHESIA TEXTBOOK DATA

From Barash's Clinical Anesthesia, 9e (Table 34-1, p. 2717):

KEY STATEMENTS FROM ANAESTHESIA TEXTBOOKS

Miller's Anesthesia, 10e (Preoperative Evaluation Chapter, pp. 3858-3859):

"More recent evidence has pointed to the nine-level CFS as being the most feasible clinical approach to accurately assess frailty during preoperative evaluation. In direct comparison of the CFS against the modified Fried Index, clinicians found the CFS to be easier to use, more feasibly applied in the clinical environment and quicker to complete (<1 minute versus 5 minutes). Web-based training modules have now been developed to support clinicians in applying the CFS in a standardized and reliable manner."

Miller's Anesthesia, 10e (Ambulatory Anaesthesia Chapter, p. 9955):

"Despite chronologic age not being associated with postoperative adverse outcomes, frailty is, with increasing scores on a frailty index associated with a stepwise increase in risk of adverse events after ambulatory surgery. There are several validated scales to assess frailty. One example is the Clinical Frailty Scale detailed in Box 68.1."

"Frailty assessment can be included in patient selection criteria for ambulatory surgery and, importantly, non-frail elderly patients should not be denied ambulatory surgery based on age."

Barash's Clinical Anesthesia, 9e (p. 2716):

"The Clinical Frailty Scale is highly feasible in clinical settings (taking less than a minute or so) and can be useful for postoperative mortality and nonhome discharge risk stratification. The Edmonton Frail Scale is a better predictor of postoperative complications. The Fried Phenotype is strongly associated with postoperative delirium."

Miller's Anesthesia, 10e (Orthopaedic Anaesthesia Chapter, p. 9153):

"A recent systematic review and meta-analysis demonstrated that amongst the available scales, the Clinical Frailty Scale had the strongest accuracy and feasibility."

BARRIERS TO ROUTINE FRAILTY ASSESSMENT

"A survey of 251 surgical oncologists reported that although most surgeons expressed interest in preoperative optimization for older patients, only 6% currently perform geriatric assessments in their older patients. In a recent qualitative study, anesthesiologists and surgeons identified key impediments to more routine frailty assessment as being the need to focus on other clinical domains (i.e., cardiorespiratory health, indication for surgery), as well as need for more training and guidelines on evidence-based efficient frailty assessment."

SUMMARY OF CFS IN ANAESTHETIC PRACTICE

• Miller's Anesthesia, 2-Volume Set, 10e - Box 68.1 (p. 9958); Preoperative Evaluation chapter (pp. 3857-3859); Orthopaedic chapter (pp. 9153-9154); Ambulatory chapter (p. 9955)
• Barash, Cullen, and Stoelting's Clinical Anesthesia, 9e - Chapter 34, pp. 2715-2718, Table 34-1 (p. 2717)