24.1 Comprehensive Geriatric Assessment, Frailty, Delirium & Falls

Geriatric medicine forms a central pillar of acute internal medical practice in the NHS. In MRCP(UK) Part 1, candidates are tested extensively on the core domains of Comprehensive Geriatric Assessment (CGA), the clinical quantification of frailty, the acute diagnosis and protocolized management of delirium, multifactorial falls risk assessment, the pharmacology of safe prescribing in polypharmacy, and pressure injury classification.

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1. Comprehensive Geriatric Assessment (CGA) & Frailty

Comprehensive Geriatric Assessment (CGA)

CGA is defined as a multidimensional, interdisciplinary diagnostic and therapeutic process designed to determine an older person's medical, psychological, functional, and environmental capabilities and limitations, formulating a coordinated, personalized care and follow-up plan.

• Evidence Base: Landmark Cochrane reviews demonstrate that hospitalised older adults undergoing formal CGA have a significantly higher likelihood of surviving and being discharged alive to their own homes (reduced institutionalisation), with reduced 30-day readmissions and improved functional independence compared to standard general medical care.
• The Five Core CGA Domains:
  1. Medical Assessment: Multimorbidity, disease severity, nutritional screening (Malnutrition Universal Screening Tool [MUST]), chronic pain, sensory impairment (vision, hearing), and structured medication review (deprescribing).
  2. Psychological & Cognitive Assessment: Cognitive screening (4AT, Mini-Mental State Examination [MMSE], Montreal Cognitive Assessment [MoCA]), delirium assessment, and mood screening (Geriatric Depression Scale [GDS-15]).
  3. Functional Capacity:
     • Basic Activities of Daily Living (BADLs / Barthel Index): Fundamental self-care tasks (feeding, bathing, grooming, dressing, toileting, continence, bed/chair transfers, and level walking).
     • Instrumental Activities of Daily Living (iADLs / Lawton-Brody Scale): Complex cognitive-motor activities necessary for independent community living (managing finances, shopping, food preparation, housekeeping, laundry, telephone usage, managing medications, and utilizing public transport). Impairment in iADLs characteristically predates loss of BADLs.
  4. Social Assessment: Informal caregiver network, caregiver strain/burnout, formal statutory social care packages, eligibility for NHS Continuing Healthcare (CHC), and durable advance care planning.
  5. Environmental Assessment: Home safety evaluation, trip hazards, access steps, lighting, grab rails, walking aids, stairlifts, telecare pendants, and ambient heating.

Clinical Frailty Scale (Rockwood CFS)

Frailty is a distinct biological syndrome characterized by a cumulative decline in physiological reserve across multiple organ systems, resulting in heightened vulnerability to disproportionate decompensation following minor physiological stressors (e.g. minor UTI, constipation, medication change).

Rockwood Clinical Frailty Scale (CFS 1–9)
  │
  ├── CFS 1 (Very Fit): Robust, active, energetic; exercises regularly
  ├── CFS 2 (Fit): No active disease; less fit than Category 1; exercises seasonally
  ├── CFS 3 (Managing Well): Medical problems controlled; not regularly active beyond walking
  ├── CFS 4 (Living with Very Mild Frailty): Not dependent; symptoms limit activities; "slowed down"
  ├── CFS 5 (Living with Mild Frailty): Evident slowing; needs help in high-order iADLs (finances, transport, meds)
  ├── CFS 6 (Living with Moderate Frailty): Needs help with all outside activities and some BADLs (bathing, dressing)
  ├── CFS 7 (Living with Severe Frailty): Completely dependent for personal care (BADLs); clinically stable
  ├── CFS 8 (Living with Very Severe Frailty): Completely dependent; approaching end-of-life from minor illness
  └── CFS 9 (Terminally Ill): Life expectancy <6 months; not otherwise living with severe frailty

• Clinical Significance:
  • A CFS score ≥5 defines established clinical frailty.
  • CFS is evaluated based on the patient's baseline functional state 2 weeks prior to acute hospital admission (avoid scoring frailty during an acute delirium or decompensated illness).
  • CFS independently predicts in-hospital mortality, institutionalisation, prolonged hospital length of stay, delirium risk, and poor post-operative outcomes.

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2. Delirium (Acute Confusional State)

Delirium is an acute, neuropsychiatric syndrome characterized by concurrent disturbances of consciousness, attention, perception, and circadian rhythms, affecting 20–30% of acute medical inpatients.

Pathophysiology & Clinical Subtypes

• Pathophysiology: Neuroinflammation driven by peripheral pro-inflammatory cytokines (IL-1, IL-6, TNF-α) disrupting the blood-brain barrier, central cholinergic deficiency, and relative dopaminergic and glutamatergic excess.
• Clinical Characteristics: Acute onset (hours to days), fluctuating course throughout the day (often worsening in the evening: 'sundowning'), marked inattention (inability to focus, sustain, or shift attention), disorganized thinking, and perceptual hallucinations.

Diagnostic Screening: The 4AT Rapid Tool

The 4AT is the validated, NICE-recommended bedside screening instrument for acute delirium (sensitivity 88%, specificity 88%):

1. Alertness: Normal (0), Mild sleepiness <10 s after waking (0), Clearly abnormal (4).
2. AMT4 (Age, Date of Birth, Place, Current Year): No errors (0), 1 error (1), 2+ errors or untestable (2).
3. Attention (Months of the year backwards): ≥7 months correct (0), Starts but <7 correct / refuses (1), Untestable (2).
4. Acute Change or Fluctuating Course: Evidence of acute alteration in mental status over past 2 weeks (4).

• Scoring Interpretation: ≥4 = Probable Delirium; 1–3 = Possible cognitive impairment; 0 = Delirium unlikely.

Precipitants: The "PINCH ME" Mnemonic

Delirium is rarely caused by a single insult; it typically represents the collision of underlying vulnerability (dementia, advanced age, sensory loss) and acute precipitants:

• P — Pain: Unrecognized surgical abdomen, occult fractures (e.g. pubic rami, femoral neck), severe arthritis, urinary retention.
• I — Infection / Sepsis: Lower respiratory tract infection, urinary tract infection, cellulitis, intra-abdominal sepsis, line infections.
• N — Nutrition: Malnutrition, severe dehydration, vitamin deficiencies (B12, folate, thiamine).
• C — Constipation: Severe faecal impaction causing discomfort and autonomic distress.
• H — Hydration / Acute Urinary Retention: Bladder distension, catheter blockage, severe hypovolaemia, prerenal acute kidney injury.
• M — Medication Changes: High-risk drug initiation, dose escalation, or abrupt drug withdrawal (anticholinergics, sedatives, benzodiazepines, opiates, corticosteroids, antiparkinsonian drugs).
• E — Electrolytes & Metabolic Derangements: Hyponatraemia, hypernatraemia, hypercalcaemia, hypoglycaemia, uremia, hepatic encephalopathy, hypoxaemia, hypercapnia, myocardial ischaemia.

Management Principles

• Non-Pharmacological Measures (FIRST-LINE & MAINSTAY): Reorientation cues (visible wall clocks, calendars), consistent nursing staff, maintaining sleep-wake cycles (quiet nights, natural daytime lighting), ensuring sensory aids (glasses, working hearing aids) are immediately restored, early mobilization, removing unnecessary catheters and cannulas, and encouragement of family presence.
• Pharmacological Intervention (LAST RESORT ONLY):
  • Reserved strictly for patients exhibiting severe intractable distress, terrifying hallucinations, or imminent physical danger to themselves or clinical staff that fails non-pharmacological calming.
  • Haloperidol (0.5 mg orally or IM, max 1–2 mg in 24 hours). Administer lowest effective dose for shortest possible duration.
  • CRITICAL CONTRAINDICATION: Haloperidol and all dopamine D2 receptor antagonists are ABSOLUTELY CONTRAINDICATED in patients with Parkinson's Disease or Dementia with Lewy Bodies (DLB). They can precipitate irreversible, catastrophic motor rigidity, acute parkinsonian crisis, or fatal Neuroleptic Malignant Syndrome. In DLB or Parkinson's disease, if sedation is vital, low-dose oral lorazepam (0.5 mg) or quetiapine (12.5–25 mg) is used.

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3. Falls in the Older Person & Orthostatic Hypotension

Falls are the leading cause of accidental injury and trauma-related death in patients over 65. In the UK, one-third of community-dwelling individuals over 65 experience a fall annually.

Multifactorial Falls Risk Assessment (NICE CG161)

Every older inpatient presenting with a fall must undergo a structured multifactorial assessment:

• Gait and Balance Evaluation: The Timed Up and Go (TUG) Test: The patient rises from a standard armchair, walks 3 metres, turns, walks back, and sits down. A time >12–15 seconds indicates impaired mobility and significantly increased fall risk.
• Polypharmacy & Medication Rationalisation: Identifying fall-risk increasing drugs (FRIDs: sedatives, hypnotics, antipsychotics, antidepressants, antihypertensives, anticholinergics).
• Sensory & Visual Testing: Refraction errors, cataracts, glaucoma, peripheral diabetic sensory neuropathy.
• Environmental Hazards: Clutter, loose rugs, inappropriate footwear, inadequate lighting.
• Cardiovascular Syncope vs Mechanical Fall: Detailed collateral history, 12-lead ECG, telemetry, echocardiography, carotid sinus massage (if carotid sinus hypersensitivity suspected).

Orthostatic (Postural) Hypotension

• Diagnostic Definition: A sustained drop in Systolic Blood Pressure (SBP) ≥20 mmHg and/or Diastolic Blood Pressure (DBP) ≥10 mmHg within 3 minutes of standing from a supine/sitting position (or an SBP drop ≥30 mmHg in patients with baseline supine systolic hypertension ≥160 mmHg).
• Pathophysiology: Age-related baroreceptor desensitization, blunted sympathetic outflow, decreased vascular compliance, venous pooling, autonomic neuropathy, and volume contraction.
• Management Strategy:
  • Step 1: Non-Pharmacological / Conservative (First-line):
    • Deprescribing culprit medications: alpha-blockers (e.g. tamsulosin, doxazosin), calcium channel blockers, nitrates, diuretics, ACE inhibitors.
    • Gradual positional changes ("sit on the edge of the bed before standing").
    • Physical counter-manoeuvres: leg-crossing, thigh contraction, squatting, buttock clenching during standing.
    • Elevation of the head of the bed by 10–15° (reduces renal arterial pressure overnight, suppressing nocturnal pressure natriuresis and maintaining intravascular volume).
    • Oral hydration (2.0–2.5 L/day) and liberalized dietary sodium.
    • Waist-high graded compression hosiery or abdominal binders.
  • Step 2: Pharmacological Therapy:
    • Fludrocortisone: Synthetic mineralocorticoid (50–200 mcg orally once daily). Promotes renal distal tubular sodium retention, expanding intravascular blood volume. Monitoring: Hypokalaemia, supine hypertension, peripheral oedema, and worsening heart failure.
    • Midodrine: Selective peripheral α1-adrenergic receptor agonist (2.5–10 mg orally three times daily). Induces peripheral arteriolar and venous vasoconstriction, boosting venous return. Caution: Administer during daytime hours; avoid dosing within 4 hours of bedtime to prevent severe supine hypertension.