Definition Aging is the progressive intrinsic universally

prevalent physiological process producing measurable changes in the structure and function of tissues and organs.

The issueThe ratio of emergency to elective surgery

increases with age. Emergencies are 60-85% Lit

Mortality (30 days)is 5-10% in elective surgery and 20-40%in emergency surgery

In the aged these figures rise dramatically to 20-25% elective and 60-80% emergency surgery.

Cardiovascular systemHeart muscle :is gradually replaced with

fibrosis and senile amyloidValvular calcification(Aortic) and mucoid

(Mitral)Overall there is a fall in COP of 1%/year

from the mid-fifties.thus in the 74-84 group the fall will be 80%.So there is little reserve to meet stresses.

Conduction defects are common.There is an increased risk of sick

sinus,BBB,AF.

Respiratory systemIncreased fibrous tissue,decreased elastin,alveolar septal breakdownChest wall calcification All the above will lead to:Decreased complianceLoss of elastic recoilIncreased ventilation/perfusion mismatch

Respiratory systemThere is an increase in FAC at the

expense of expiratory reserve volume(ERV). Vital capacity(VC) is therefore reduced

Small airways close even during tidal breathing.

Elderly show a marked reduction in ventilatory response to hypoxia and hypercapnia.

THERE IS AN INCREASED RISK OF APNOIC ATTACKS DURING SLEEP

HEPATIC FUNCTIONReduction in hepatic mass is 40% by the age of

80 years. Function is mainly preserved but some specific microsomal mixed oxidase systems are notably affected

Renal functionGFR normally 120ml/min falls by 8 ml every

decade after the age of 20 .Thus an 80 years old may have a GFR that is

reduced by 45% ie 65ml/min .This is a 50%reduction of the functioning

nephronsThere is an impaired responsiveness to ADH and

decreased ability to concentrate urine30% of patients over 75 years of age undergo

surgery with coexisting renal impairementARF is responsible for 20% of perioperative

deaths in elderly.

Metabolism There is a decreased ability to handle glucose

load

Type II NIDD is common 4%

Hypothyroidism 3%

Intra-operative and post-operative core temperature are lower in elderly.

Body compositionBy 65 years there is a decrease of 25%

and 28% in total body water for males and females respectively.

There is a relative increase in lipid fraction and loss of skeletal mass.

Osteoporosis in 30% of womenOsteomalacia in 5% of aged population3% of elderly have paget’s disease this

may rise to 11% by 90 years85% of elderly have radiological OA.Anaemia all types is present in 12%

Pharmacokinetics Regular medication is consumed by 75% of

patients.30% take 4 or more drugs/day.Noncompliance is estimated at 60% and adverse

drug reaction increaese from 20% in middle age to 30% in the aged .

Drug absorption is little affected by ageBut because of the relative increase in the lipid

fraction of the body compositon the volume of distribution of fat soluble drugs like diazepam ,lignocaine is increased,where as the distribution of polar drugs digoxin is reduced

Pharmacokinetics DrugDiureicsAnalgesicsTranquilizersAntidepressantsHypnoticsdigitalis

Population35%30%25%25%20%20%

Pharmacokinetics

Surgery in the elderly

Pharmacokinetics Because of reduced GFR several drugs

accumulate if given in young adult dose.

The half-life of benzodiazepines may extend 5 folds.

Diuretics can produce hypotension,hypovolaemia,decrease K,and potentiate the digitalis toxicity

Oral hypoglycaemics should be stopped 48 hours before surgery

Pharmacokinetics Oral hypoglycaemics should be stopped 48 hours

before surgery

Drugs with anti cholinergic activity like tricyclic antidepressants ,phenothiazines are more likely to precipitate urine retention and constipation.

End receptor sensitivity may be increased with hypnotics and may cause postoperative confusion

Per operative risk and outcome

In the over 65 years old the overall mortality is for major surgery defined as death within 30 days is 10%

The risk of per operative mortality increases with age

Morbidity is related to age-related chronic medical problems

Isolated diseases is unlikely in the over 75 years

Premorbid state of heathRespiratory system in 30%Cardiovascular system: MI in over 65 years 1-

3%.50% of it is silent.Re infarction is 35%Heart failure 5-10 %Deep vein thrombosis and pulmonary embolism

increases with ageStroke in over 65 years is 1%

We can improve itThe problem will continue to rise as the projected

increase over the coming 10 years is more than 40% increase .

Aortic aneurysm repair, incarcerated hernia and biliary calculus disease are three areas where marked differences in outcome can be anticipated (elective versus emergency surgery)

What to do?The world demographic changes have produced a

vast majority of geriatric population .

A rigorous search for preoperative heart failure, renal failure and hydration imbalance must be conducted

Close monitoring of all postoperative aged patients is essential