Session 2: Ageing, Dementia and Nutrition in the Elderly Flashcards
Effects on the respiratory system in the elderly.
Lung and chest wall compliance decrease with advancing age leading to reduction in, TLC, FVC, FEV1 and VC.
Why is lung and chest wall compliance reduced in advancing ages?
Reduction in elastic support of the airways.
This leads to increased collapsibility of alveoli and terminal conducting airways.
Common post-operative complications in the elderly.
Atelectasis
PE
Pneumonia
When are post-operative complications increasingly common in elderly patients?
When they are also smokers, if they have chronic chest disease etc…
What might cause partial or complete obstruction of the airways in elderly?
Sleep or sedative states
Due to loss of elastic tissue around the oropharynx cwhich can lead to collapse of upper airway.
Pharmacokinetics in elderly.
An increased sensitivity to CNS depressant drugs due to reduced hepatic and renal function leading to slower metabolism and elimination of drugs.
Skin changes in elderly.
Thin and fragile skin with fragile subcutaneous blood vessels.
This leads to easy bruising.
It might also be hard to achieve and secure venous access.
Effects on bloods vessels in ageing people.
Large and medium sized vessels become less elastic and hence less compliant.
What effect do the changes in blood vessels have?
Raised systemic vascular resistance and hypertension.
Can lead to left ventricular strain and left ventricular hypertrophy.
Effects of ageing on the heart itself.
Cardiac conducting cells decrease in number making heart block, ectopic beats, arrhythmias and atrial fibrillation more common.
How does cardiac output change in ageing and why?
Roughly 3% per decade due to reduced stroke volume and ventricular contractility.
What does the reduction in cardiac output mean for IV anaesthesia?
Means it is achieved more slowly and with reduced doses of anaesthetic agent. The onset is delayed.
This is because there is an increase in the arm-brain circulation time.
Other pharmacological effects of ageing.
Reduced total body water and increased adipose tissue also leads to an altered volume of distribution of some drugs.
There is also a reduction in plasma proteins leading to decreased protein binding and increased free drug availability.
Effects on renal system of ageing.
GFR thought to decrease by 1% per year over the age of 20 years.
This is due to the progressive loss of renal cortical glomeruli.
It can also be secondary to reduced CO or atheromatous vascular disease.
Common causes of renal pathology in elderly.
Diabetes mellitus
NSAIDs
ACE inhibitors
Prostatism in males leading to obstructive nephropathy and dehydration.
