Pulmonary embolism can strike anyone, including those who play computer games for long hours without taking a break. CHIA HUI JUN reports

Tennis star Serena Williams needed emergency treatment at the end of last month when she developed complications from a pulmonary embolism, a blood clot that blocks a major artery feeding the lungs.

In Singapore, Dr Lim See Lim, a senior consultant in the department of cardiothoracic surgery at the National Heart Centre Singapore, recounted a recent case where a man in his 20s nearly collapsed as he was leaving his house. He had been lying in bed for a few days with a thigh injury sustained in a traffic accident.

A CT scan showed he had a pulmonary embolism.

Pulmonary embolism is the second most common cause of sudden death worldwide after cardiac arrest, which is most commonly caused by coronary artery disease, said Associate Professor Philip Eng, a senior consultant respiratory physician at Mount Elizabeth Hospital.

When a person is immobile for long periods, blood stagnates in the deep veins in the legs. This can cause clots to form, leading to a condition called deep vein thrombosis, said Dr Lim.

After long flights

This happens most frequently after long flights, but could also follow periods of inactivity, such as being bedbound or after surgery.

'We have also seen young patients who play computer games for long hours without taking a break,' Dr Lim said.

When the person gets up to walk, the blood clot may dislodge, travel up to the heart and end up lodged in the major arteries of the lungs, resulting in an embolism.

Breathlessness, chest pain and palpitations are the most common symptoms of pulmonary embolism, Dr Lim said.

People may faint or even cough up blood, said Dr Eng.

In the case Dr Lim referred to, the patient was rushed to hospital and a breathing tube was inserted in his throat before he was treated at the National Heart Centre Singapore.

Anticoagulants such as warfarin are often given to prevent new blood clots from forming. Thrombolytics may also be given to dissolve the clots.

In the more severe cases, when massive clotting chokes up the pulmonary arteries and the patient's blood pressure is unstable, emergency surgical treatment to remove the clot is necessary.

This rarely-done procedure known as pulmonary embolectomy typically takes two to three hours and involves opening the pulmonary artery to remove the blood clots while the patient's circulation is supported with a heart-lung machine.

When we walk, our calf muscles massage the deep veins in the legs, increasing the blood flow. People who take long flights should exercise their calf muscles and flex and extend their feet frequently, Dr Lim said.

Dr Eng advised air travellers to hydrate themselves well, avoid alcohol or wearing tight-fitting clothes.

Other risk factors include smoking, pregnancy or being on birth control pills or hormone replacement therapy.

Dr Eng once treated a young patient on birth control pills who developed the condition. Another patient in his 50s, who was being treated for pneumonia, had blood clots in both his right and left lungs.

Source: The Straits Times © Singapore Press Holdings Limited. Permission required for reproduction.