Ageing lowers the ceiling, not the floor: baseline function survives, the surplus that carries a person through pneumonia or a fluid bolus does not. Move the dials and watch reserve narrow while a perfectly normal creatinine hides a clearance of 30 mL/min. Then sort real findings into normal ageing or needs a workup, and decode the four presentations that acute illness actually uses in this population.
The patient
Age87 years
Weight48 kg
Serum creatinine1.0 mg/dL
Laboratory reference is roughly 0.6–1.2 mg/dL — and it is a product of muscle mass.
Sex
Try a patient
Cockcroft–Gault. Creatinine clearance = (140 − age) × weight in kg ÷ (72 × serum creatinine), × 0.85 for women.
Finding
0 of 0
The rule. Confusion, incontinence, falling, weight loss, chest pain, depression and anaemia are never normal ageing. Wrinkled skin, presbyopia, a higher systolic pressure and a slower gait are.
The four cardinal presentations
The traps worth memorising
30Creatinine clearance
Read the number
What this changes at the bedside
?Sort the findingPick a bin on the left.
WhyEvery finding below is real. Decide whether you would chart it as baseline or work it up — and know the number that decides it.
The habit that protects the patient“She’s just old” is not an assessment finding. Every time you are tempted to blame a new symptom on age, ask what you would work up if the patient were forty. Ninety percent of the time that is the correct plan.
?Atypical presentationPick a presentation on the left.
Function is the vital sign of geriatricsOlder adults present with a change in function rather than a change in symptoms. New confusion, a fall, new incontinence and simply not eating or not getting out of bed are all non-specific — and all four are legitimate reasons to work the patient up for acute illness.