An 82-year-old can be robust, do sport, tolerate ten medications without any problem. A 72-year-old can be frail, take a long time to recover after an infection, fall during the night. Both have the same chronological age stated in their medical records. But their biological resilience is completely different.
This explains why the conventional ASA score (American Society of Anesthesiologists Score) often underestimates the risks in older people. It assesses underlying diseases — not reserve. More modern risk scores (NSQIP, POSSUM, dedicated geriatric frailty scores) have considerably better prognostic value in the age group over 70.
→ What frailty means and how it is measured, we explain in the article Frailty syndrome.
Four complications dominate the picture after operations in old age. Each is relevant, each is at least partly avoidable.
1. Postoperative delirium (POD)
Postoperative delirium is the most common neuropsychiatric complication in older surgical patients. The frequency varies greatly:
- After elective procedures: 10 to 20 percent
- After hip fracture operations: 30 to 50 percent
- In intensive care units after cardiac surgical procedures: 50 to 80 percent
Delirium is not a harmless transitional phenomenon. It prolongs the hospital stay by an average of five to ten days, increases mortality and doubles the risk of developing dementia in old age in the following years.
→ In detail on this: Delirium in older people — recognizing and treating it. And on prevention: Delirium prevention.
2. Postoperative cognitive dysfunction (POCD)
In contrast to delirium, POCD is a gradual, longer-lasting deterioration in cognitive performance that can persist for weeks to months after the procedure. The frequency after major operations is 20 to 30 percent, still about 10 percent after three months. The precise mechanisms are the subject of intensive research — inflammation, blood pressure fluctuations, postoperative delirium and anesthetics all play a role. With pre-existing mild cognitive impairment (MCI), the risk is increased.
3. Functional decline
The underestimated but prognostically decisive factor. About 30 to 60 percent of older patients leave hospital with a poorer functional status than they had on admission. One third does not fully return to the baseline level. This is the path from independent living to the nursing home — often triggered by an operation that went surgically perfectly. Early geriatric early rehabilitation can specifically counteract this decline. Accompanying immobility in old age should also be addressed early.
4. Complications and increased mortality
Pneumonia in old age, thrombosis, wound healing disorders, kidney failure — the classic surgical complications occur more frequently and with more severe courses in older patients. The 30-day mortality after major procedures rises significantly with age, but depends far more strongly on frailty status than on the chronological age.
The Comprehensive Geriatric Assessment (CGA) before an operation is the structured process by which the individual resilience is assessed and targeted optimization is planned. It usually takes 60 to 90 minutes and covers seven dimensions:
- Functional status: Barthel index, Timed-Up-and-Go, grip strength measurement.
- Frailty assessment: Clinical Frailty Scale or Fried phenotype. In addition, a frailty screening is recommended.
- Cognition: MMSE or MoCA to assess dementia risk and susceptibility to POD.
- Mood: Geriatric Depression Scale (GDS) — depression in old age is an independent risk factor for postoperative complications.
- Nutritional status: Mini Nutritional Assessment (MNA). Malnutrition in old age before an operation considerably increases the risk of infection and wound healing.
- Medication review: According to PRISCUS and FORTA — with particular attention to substances with a bleeding risk, delirium potential or problematic interactions with anesthetics. The key term being deprescribing.
- Social environment: Who supports the patient after discharge? What aftercare can be organized?
→ How a complete geriatric assessment works in detail: Geriatric assessment.
Prehabilitation is perhaps one of the most important advances in perioperative medicine in recent years. The basic idea: the weeks before a planned procedure are not a waiting room, but the best therapeutic window. What is built up in this time pays off many times over postoperatively.
The core components
- Progressive strength and endurance training: Two to four weeks of targeted training can substantially shorten the postoperative recovery time — particularly important with pre-existing sarcopenia.
- Optimization of nutrition: Protein intake of 1.2 to 1.5 g per kg of body weight. In cases of malnutrition in old age, oral nutritional supplements and nutritional therapy support.
- Medication optimization: Discontinuing or switching potentially unsuitable preparations — valuable time especially before elective operations. More on deprescribing.
- Smoking cessation: Even four weeks smoke-free before an operation significantly reduces wound healing disorders.
- Optimization of underlying diseases: Diabetes in old age, heart failure in old age, COPD — every stabilization before the operation lowers the risk of complications.
- Psychological preparation: Informed consent is more important than the signature on a form. Anyone who understands what is happening experiences less anxiety and less delirium.
Randomised studies on prehabilitation before colorectal surgery, hip endoprosthetics and cardiac surgical procedures show consistent results: shorter length of stay, fewer complications, faster return to independence. The investment of four to six weeks of prehabilitation before a plannable procedure is one of the rare clearly evidence-based recommendations in perioperative medicine.
The modern preoperative discussion is never a monologue. It is an interdisciplinary discussion in which three specialist perspectives come together:
- The surgeon: assesses the procedure — technical feasibility, type and scope, urgency, expected benefit.
- The anesthesiologist: assesses the immediate anesthetic and intraoperative risks.
- The geriatrician: assesses the overall resilience, the expected recovery and the preoperative scope for optimization. The basis is the geriatric specialty.
In orthopedic and general surgical departments that work in a structured way with geriatric medicine, measurable differences are evident: lower delirium rates, shorter lengths of stay, a higher rate of return to independent living. This applies in particular to hip endoprosthetics and proximal femoral fractures — a core area of geriatric traumatology.
→ Specifically on the hip prosthesis in older patients: Total hip replacement from age 80 and geriatric co-care.
→ On knee endoprosthetics in old age: Knee prosthesis — what older patients should know.
→ On orthopedic joint replacement as a whole: Joint replacement in old age.
The honest answer to an uncomfortable question: not every technically feasible operation is clinically advisable. In cases of pronounced frailty, advanced dementia in old age or a very limited life expectancy, the harm of an operation can outweigh the benefit — even if the diagnosis would justify it.
Geriatrics has a specific role here: it helps to clarify treatment goals before technical questions are decided. “What is important to you when you imagine the rest of your life?” is not a philosophical question. It is the clinical anchor point of every honest decision-making process. An advance directive drawn up in good time can provide important guidance here. In addition, early involvement of palliative medicine in old age is recommended.
???? For every planned major operation in an older relative: actively ask for a preoperative geriatric assessment. This is not a luxury, it is the standard of modern geriatric medicine — even if it is not yet offered systematically in many hospitals.
At what age does an operation become too risky?
It is not the chronological age that decides, but the frailty status and the individual resilience. A robust 85-year-old can come through a hip operation well, while a frail 72-year-old has a significantly higher risk of complications. The Clinical Frailty Scale and the preoperative geriatric assessment give better answers than the age alone.
What is the difference between delirium and dementia after an operation?
A delirium is an acutely setting-in state of confusion — usually in the first days after the operation, fluctuating in its course, in most cases reversible. Dementia in old age develops over months to years and is not reversible. A postoperative delirium can, however, increase the risk of later developing dementia — this is one of the reasons why delirium prevention is not a minor matter.
How long before an operation should prehabilitation begin?
Ideally four to six weeks before the planned procedure. Even two weeks of structured preparation still show relevant effects in studies. Prehabilitation includes training, nutritional optimization, medication review, smoking cessation and, where applicable, treatment of underlying diseases not yet optimized, such as osteoporosis in old age or polypharmacy.
Can I, as a relative, request a geriatric assessment?
Yes. Actively approach the surgeon or anesthesiologist and ask for a geriatric co-evaluation before a planned major operation. In many clinics this is already part of the standard process for patients over 75 — in others it has to be explicitly requested. You have the right to this assessment.
Which medications should be discontinued before an operation?
The treatment team decides this individually — benzodiazepines, certain antidepressants and anticholinergic substances should be reduced beforehand where possible. Anticoagulants are paused according to specific protocols. Diabetes and blood pressure medication is often adjusted on the day of surgery. Never discontinue medications on your own — this can be more dangerous than continuing them. More on this: Deprescribing.
