2020.1 SAQ 15 Ageing and the respiratory system

I recently visited Kangaroo Island which was ravaged by bushfires earlier this year. One thing that has flourished amidst the devastation is the grass tree. They are very slow growing, so these beautiful specimens are old but doing all they can to ensure the species survives.

Discuss the effects of ageing on the respiratory system.

Increasingly, we are having to anaesthetise older and extremely old patients. It is important to know how their physiology differs from younger patients in order to deliver the best possible care.

BT_PO 1.37 Discuss the effect of ageing on ventilation

There is another post on this topic here and as I mentioned in that post, I think that Nunn’s Applied Respiratory Physiology is the best for this subject (unfortunately the references are dotted throughout the book)

PaCO2 levels rise as a part of normal ageing due to a reduced capacity for diffusion T/F

PaO2 levels fall gradually as part of the normal ageing process T/F

The ventilatory response to hyercapnoea is blunted with ageing T/F

Compliance of the chest wall decreases with ageing due to decreased mobility of the costochondral joints T/F

FRC decreases as part of the normal process of ageing T/F

Static compliance of the lungs falls with advancing age T/F

2019.1 SAQ 2 – cardiovascular effects of ageing

Describe the cardiovascular changes that occur with ageing .

If your practice is anything like mine, you will be looking after a lot of older patients. Changes in the cardiovascular system are important to us as they impact how the elderly respond to anaesthesia.

There has been a previous post of this topic here for those of you wanting a bit more practice

There is a new chapter in the second edition of Hemmings and Egan Pharmacology and Physiology for Anaesthesia which covers the physiological changes associated with ageing. There is also a chapter devoted to ageing in Power and Kam’s book.

BT_PO 1.49 Describe the cardiovascular changes that occur with ageing

Decreased compliance of the vessels results in an increased pulse pressure T/F

Older people have a reduced response to sympathetic stimulation because circulating levels of catecholamines are lower T/F

Fibrosis of the conducting system increases the risk of arrhythmias T/F

Blood volume, on a mL/kg basis, increases with advancing age T/F

Fibrosis of the heart impairs both filling and ejection of blood from the heart T/F

BT_RT 1.30 Outline how the clinical signs of shock may be altered by age

I love this time of year ….

This quite a good LO for making you think about the differences in the cardiovascular system and associated reflexes throughout the age spectrum. If you know what happens to the CVS as we age, then you should be able to predict what may happen in times of stress.

Many of you will be familiar with the ATLS grading of haemorrhage and the associated signs. These are not great for predicting blood loss the elderly, can you think why…

All of these statements should be within your capabilities.

Miller’s Anaesthesia has a chapter on Geriatric Anaesthesia which discusses the physiological changes in the elderly.

BT_RT 1.30 Outline how the clinical signs of shock may be altered by age

Tachycardia is likely to be less pronounced in a patient of 80 compared to one of 40 with the same degree of blood loss T/F

The baroreceptor reflex becomes progressively less effective with increasing age T/F

High resting sympathetic tone in the elderly, has more of an effect on α-adrenoreptor responsiveness compared with β -adrenoceptor responsiveness T/F

Elderly patients with septic shock are more likely to present with hypothermia than younger individuals T/F

Hypotension is a sign of severe shock in children T/F (the added complication of this one is knowing what is the normal blood pressure for your paediatric patient)