Friday, March 22

Pneumonia can be deadly for those with weak immunity

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A COMMON condition, pneumonia can turn deadly for the elderly and those with weakened immune systems.

It is a common medical condition that can clear up on its own or with a course of antibiotics. But pneumonia can easily turn deadly among the elderly and those with weakened immune systems.

Not surprisingly, pneumonia ranks second to cancer as the most common cause of death in Singapore. According to Ministry of Health statistics, pneumonia accounted for 19 per cent of deaths in 2014, up from 18.5 per cent in 2013 and 16.8 per cent in 2012.

“In severe cases, pneumonia can cause the lungs to fail and the patient will need to be admitted to the ICU (intensive care unit) for artificial life support,” said Dr Jessica Tan, Associate Consultant, Department of Respiratory and Critical Care Medicine, Singapore General Hospital (SGH).

“Despite antibiotics and ICU support, some patients still die. As with all cases of bad infection, it can lead to other problems like multi-organ failure, kidney failure and sepsis. That’s why we treat it very seriously, particularly when it affects the elderly.”

The disease is most commonly caused by the streptococcus pneumonia bacteria and viruses like those that cause influenza. “In influenza, the upper airways are affected first. If the patient has a weakened immune system, the virus can invade and move down into the lung tissue,” said Dr Tan.

Pneumonia starts simply enough as a throat infection, common flu or cold. Patients experience symptoms such as fever, chills, shivering, cough and throat infection. But because pneumonia affects the lower airways and lungs, patients are also likely to suffer from breathlessness and chest pain. A doctor listening to the chest with a stethoscope might hear rattling sounds not normally present.

“When pneumonia is suspected, a chest x-ray will be ordered to confirm the diagnosis,” said Dr Tan.

When a person has pneumonia, his x-ray image will show a patch in his lung. This means that the lung is inflamed and filled with pus and mucus which prevents the person from breathing properly. “In serious cases, a lot of the functioning lung will be clogged by inflammatory cells and infected secretions. The patient will have low blood oxygen levels and difficulty breathing, and will end up requiring ICU admission and ventilator support,” said Dr Tan, noting that a ventilator supports the patient in breathing and getting enough oxygen while antibiotics go to work to fight the infection.

In mild cases of pneumonia, antibiotics usually clear up the infection within a week or so. In severe cases, patients may require more than one type of antibiotic, delivered intravenously. About

a fifth – 15-20 per cent – of pneumonia patients will need hospital treatment, and an estimated 40 per cent of the very serious cases will succumb to the disease, she added.

Most of the patients (60-70 per cent) who are admitted to SGH for pneumonia are above the age of 65, said Dr Tan. “Our immune system weakens with age, which makes the elderly less able to deal with infections. At the same time, they often have other medical conditions such as diabetes and heart disease which can complicate treatment,” she said.

Older people are just one of several groups at higher risk of developing pneumonia. People with chronic lung diseases, smokers with COPD (chronic obstructive pulmonary disease), those with organ failure or weakened immune systems, or who are on chemotherapy (for cancer treatment) and immunosuppresants (following transplants) are also at risk.

For these groups, one of the best ways to avoid contracting pneumonia is to get vaccinated. A yearly flu shot helps one avoid catching the flu easily while the pneumococcal vaccine can help prevent serious infections caused by the streptococcus bacteria. For people above 65, a single dose of the vaccine is enough.

The two vaccinations do not prevent all types of pneumonia as there are many different strands of bacteria and viruses. “But it prevents the serious infection caused by some strains. It is often recommended that at-risk groups go for vaccinations,” Dr Tan said.

Following good lifestyle habits such as having enough rest, water and exercise, and a balanced diet, will strengthen a person’s immunity so that when he comes down with pneumonia, he can fight the infection more easily.

• This story was first published in Singapore Health, May-Jun 2016 issue.