Zimbabwean Academic Examines Aspects of “Surgery in the Elderly”

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“Surgery in the Elderly – Changes, Risks and Complications” was the title of a presentation by the University of Zimbabwe’s Dr Linda Kumirayi at the Nelson R Mandela School of Medicine in Durban.

Kumirayi presented on Day 2 of the Surgical Registrar Conference hosted by the South African Society of Surgeons in Training (SASSIT) and UKZN’s Department of Surgery.

Kumirayi explained that there was a difference between chronological age and physiological age which resulted in heterogeneity within the elderly population. Elderly patients therefore needed to be regarded as individuals.

She said elderly people could be further categorised - based on their chronological age - as ‘young old’ from 65 – 74 years, ‘old old’ from 75 – 84 years and ‘oldest old’ for those more than 85 years old.

With an aging population and a significant baby boomer generation in the United States, interest had grown in the field of gerontology. Life expectancy in the US was now around 78 years while in Africa, it was 58 years.

Kumirayi said with aging came the risk of diseases such as malignancies, infections, coronary and valvular heart diseases as well as degenerative joint diseases. There were many myths about old age - for example, saying old people did not tolerate surgery at all or that illnesses were a sign of aging so should be accepted.

‘All systems are affected in the aging process – both the physiological and anatomical. Importantly there is a decrease in physiological reserve.’

Kumirayi said within the cardiovascular system, the heart was less compliant in an elderly patient due to the changes in the myocardium and in the conduction system.

The respiratory system function was considerably weakened due to the loss of chest wall compliance, flattening of the diaphragm and lung parenchymal changes due to a loss of elastic tissue. ‘There is loss of neuronal tissue with aging as well as reduced cerebral blood flow. The Blood Brain Barrier is less efficient such that the aged brain has increased sensitivity to centrally acting drugs. Overall there is poor reflex control in terms of baroreception and thermoregulation,’ said Kumirayi.

‘With aging there is weakening of the immune system. In the presence of severe infection, an elderly patient may have an atypical presentation such as a normal white cell count, normal temperature and absence of pain. Elderly patients therefore tend to present late and with complications. Also there is an accumulation of auto anti-bodies and reduction in the naïve T cell population.

‘Due to poor peripheral blood supply and loss of collagen and elastic tissue, the skin in old people is weakened and they become prone to decubitus ulcers. HIV infection prevalence in the elderly population is comparable to the general population but the increase in occurrence of other co-morbidities make the elderly patient more prone to the complications of the disease.

‘Poly pharmacy is common in elderly patients as most are on medication for some other chronic illnesses such as arthritis hypertension and diabetes. It is vital for a doctor therefore to review the patient’s medication before commencing any treatment.

‘Occupation, lifestyle, co-morbidities, medications, hearing, visual impairment and previous medical surgical history all contribute to an elderly person’s risk assessment. Frailty, scored by the presence of weight loss, weak grip strength, self-reported exhaustion, slow walking speed and low energy expenditure has a bearing on prognosis with scores of four to five being associated with increased morbidity and mortality,’ she said.

‘Use of ß-Blockers, statins, and stopping of smoking can reduce an old person’s risk of post-operative complications.’

Kumirayi also mentioned the following in her presentation:

* Delirium in the elderly – it is vital to identify and manage the cause. Optimisation of oxygenation, metabolism as well as fluid balance plus adequate pain control help in preventing occurrence as well as early resolution of the condition.

*Cardiovascular complications such as hypotension can occur, it is therefore important to maintain a good preload by adequate hydration.

* Myocardial infarctions as well as venous thrombo-embolism are among important complications to look out for.

* Respiratory complications such as ventilator dependency, aspiration and pneumonia can occur. A loss of co-ordinated swallowing reflex and increase in time for gastric emptying increases the risk of aspiration.

* Renal complications such as uraemia and electrolyte derangements can occur when there is hypotension or use of nephrotoxic drugs.

* Metabolic complications including hypothermia and hypoglycaemia can be prevented by taking the necessary precautions and monitoring temperature plus glucose levels respectively. Prevention strategies include the use of minimally invasive surgical options, setting of realistic goals of therapy, having a multi-disciplinary approach as well as patient and family involvement.

Kumirayi concluded that elderly patients had acceptable survival rates after surgery, but tolerated complications poorly. Good results were linked to a smooth, uneventful postoperative recovery.

-           Words and photograph: Zakia Jeewa