Introduction
Population ageing is one of the most significant healthcare challenges of the twenty-first century. According to the World Health Organization, the number of people aged 60 years and above is expected to double by 2050. Consequently, hospitals are caring for increasing numbers of older adults with complex medical and social needs.
Older patients rarely present with isolated diseases. Instead, they often exhibit overlapping syndromes such as frailty, delirium, falls, immobility, cognitive impairment, and polypharmacy. These factors complicate diagnosis, prolong hospital stay, and increase the risk of adverse outcomes.
Acute Internal Medicine (AIM) has emerged as a specialty focused on the rapid assessment, stabilization, and management of patients with acute medical illnesses. While traditionally centred on acute disease management, AIM increasingly overlaps with geriatric medicine due to the demographic realities of modern healthcare.
The Changing Face of Acute Medical Admissions
Across many healthcare systems, older adults account for the majority of acute medical admissions. Studies consistently demonstrate that patients aged over 75 years occupy a disproportionate number of hospital beds and consume substantial healthcare resources.
Unlike younger adults, older patients frequently present with non-specific symptoms such as:
· Falls
· Confusion
· Functional decline
· Reduced mobility
· Generalized weakness
· Failure to cope at home
These presentations often represent underlying acute illness such as infection, heart failure, myocardial infarction, or metabolic disturbances.
Consequently, acute physicians must look beyond organ-specific diagnoses and adopt a holistic approach to patient assessment.
Frailty: The New Vital Sign
Frailty has become one of the most important concepts in modern acute care.
Frailty is a state of reduced physiological reserve resulting in increased vulnerability to stressors. Even minor illnesses can precipitate significant deterioration in function, cognition, and independence.
Recognition of frailty in the Acute Medical Unit (AMU) allows clinicians to:
· Predict clinical outcomes
· Identify patients at risk of deterioration
· Guide treatment intensity
· Facilitate discharge planning
· Trigger early geriatric assessment
Tools commonly used include:
· Clinical Frailty Scale (CFS)
· Frailty Index
· Edmonton Frail Scale
Many experts now advocate considering frailty assessment as important as traditional vital signs during acute admissions.
Acute Internal Medicine and Comprehensive Geriatric Assessment
Comprehensive Geriatric Assessment (CGA) remains the gold standard for evaluating older adults with complex needs.
CGA evaluates multiple domains:
Medical
· Multimorbidity
· Polypharmacy
· Nutritional status
· Sensory impairment
Functional
· Activities of Daily Living(ADL)
· Instrumental Activities of Daily Living (IADL)
· Mobility assessment
Cognitive
· Delirium
· Dementia
· Depression
Social
· Caregiver support
· Living arrangements
· Community resources
Acute physicians increasingly incorporate elements of CGA into routine practice, especially in Acute Medical Units. Early identification of geriatric syndromes allows interventions to begin during the first hours of admission rather than waiting for specialist review.
Delirium: A Medical Emergency
Delirium affects up to one-third of hospitalized older adults and is associated with increased mortality, prolonged hospitalization, institutionalization, and cognitive decline.
Acute physicians are often the first clinicians to encounter delirium. Recognition requires a high index of suspicion because hypoactive delirium is frequently missed.
Key responsibilities include:
· Early screening using tools such as 4AT
· Identification of precipitating factors
· Medication review
· Management of pain, dehydration, and infection
· Prevention of hospital-acquired complications
Delirium should be regarded as a medical emergency requiring the same urgency as acute stroke or sepsis.
Polypharmacyand Medication Optimisation
Polypharmacy remains one of the most common challenges in acute geriatric care.
Many older adults admitted to hospital take more than five medications, with some receiving more than ten.
Acute physicians play an important role in:
· Medication reconciliation
· Identification of potentially inappropriate medications
· Recognition of drug-drug interactions
· Deprescribing unnecessary therapies
Tools such as the Beers Criteria and STOPP/START criteria can facilitate safer prescribing practices.
Early Supported Discharge and Hospital Avoidance
Prolonged hospitalization in older adults is associated with:
· Deconditioning
· Functional decline
· Delirium
· Hospital-acquired infections
Acute Internal Medicine services increasingly emphasize early discharge planning from the point of admission.
Collaboration with:
· Geriatricians
· Physiotherapists
· Occupational therapists
· Social workers
· Community nursing teams
can reduce unnecessary hospital stay while maintaining patient safety.
The concept of “home first” has gained prominence, recognizing that recovery is often optimized within familiar environments.
Advance Care Planning and Goals of Care
Many older adults admitted with acute illness are approaching the final stages of life.
Acute physicians frequently encounter situations requiring decisions regarding:
· Intensive care admission
· Cardiopulmonary resuscitation
· Dialysis
· Artificial nutrition
· Escalation of treatment
Therefore, advance care planning should become a routine component of acute medical care.
Effective conversations should focus on:
· Patient values
· Quality of life
· Treatment preferences
· Realistic outcomes
Such discussions ensure that care remains aligned with patient goals while avoiding burdensome interventions.
TheFuture: Integrated Acute Frailty Services
Several healthcare systems have introduced Acute Frailty Units and Same-Day Emergency Care pathways specifically designed for older adults.
These services aim to:
· Deliver rapid frailty assessment
· Prevent unnecessary admission
· Reduce hospital-associated complications
· Improve patient experience
· Enhance healthcare efficiency
Acute physicians are ideally positioned to lead these services due to their expertise in rapid diagnosis, risk stratification, and multidisciplinary coordination.
The future of AIM is likely to involve increasingly close collaboration with geriatric medicine, creating integrated models that combine acute medical expertise with principles of comprehensive geriatric care.
Conclusion
The role of Acute Internal Medicine extends far beyond the treatment of acute disease. As populations age, acute physicians increasingly manage frailty, delirium, multimorbidity, polypharmacy, and end-of-life decision-making. Incorporating geriatric principles into acute medical practice is essential for delivering high-quality, patient-centred care.
Rather than viewing acute medicine and geriatrics as separate disciplines, healthcare systems should embrace a collaborative model in which acute physicians and geriatricians work together to address the complex needs of older adults. Such integration represents one of the most important developments in modern hospital medicine and will be fundamental to meeting the healthcare challenges of an ageing world.
References
- Rockwood K, Song X, MacKnight C, et al. A global clinical measure of fitness and frailty in elderly people. CMAJ. 2005;173(5):489-495.
- Ellis G, Whitehead MA, Robinson D, O’Neill D, Langhorne P. Comprehensive geriatric assessment for older adults admitted to hospital. Cochrane Database Syst Rev. 2017.
- National Institute for Health and Care Excellence (NICE). Multimorbidity: Clinical Assessment and Management. NICE Guideline NG56.
- British Geriatrics Society. Fit for Frailty Part 1 and Part 2. London: BGS.
- Royal College of Physicians. Acute Care Toolkit: Acute Frailty. London: RCP.
- World Health Organization. Integrated Care for Older People (ICOPE): Guidance for Person-Centred Assessment and pathways in Primary Care.