Many people died suddenly from pulmonary embolism while riding long-distance buses! How to diagnose and prevent it?

As the Spring Festival holiday comes to an end, workers are starting to return to work. How long does it take for you to return? Many people have to travel a long time by car because of the long distance. But do you know? Long-term car travel without exercise is not only tiring but also has health risks.

According to Guangzhou Daily, on the way back to work after the recent Spring Festival holiday, several patients suffered from acute pulmonary embolism due to long-term car sitting, and three people unfortunately died.

Many returning migrant workers suffered from acute pulmonary embolism

On the morning of February 17, 2024, the eighth day of the first lunar month, 47-year-old Ms. Ao rushed from her hometown of Zunyi, Guizhou to Houjie Town, Dongguan City after taking a long-distance bus for more than 20 hours. Not long after getting off the bus, she suddenly fainted and became unconscious. She did not respond to calls, and her fellow villagers quickly called 120. When the emergency personnel from Houjie Hospital arrived at the scene, she had no breathing and heartbeat.

The medical staff immediately performed cardiopulmonary resuscitation and immediately transferred her back to the emergency department of the hospital, where they gave her a series of rescue measures, including continuous external chest compressions, endotracheal intubation and ventilator-assisted ventilation. After 26 minutes, her heartbeat resumed, but her blood oxygen was low, her heartbeat was unstable, and her heartbeat continued to stop repeatedly. The hospital tried its best to treat her and performed interventional treatment for her with the assistance of a cardiopulmonary resuscitation device and a ventilator. After the operation, she was sent to the Department of Emergency and Critical Care Medicine for further treatment. The patient's heartbeat and blood oxygen gradually stabilized, but she remained in a deep coma, with dilated and fixed pupils. Hypoxic-ischemic encephalopathy was considered and was difficult to reverse. On February 21, Ms. Ao was confirmed dead.

Li Jinting, director of the Department of Emergency and Critical Care Medicine at Houjie Hospital, said that the patient's lower limb venous ultrasound showed lower limb venous thrombosis, and the electrocardiogram showed complete right bundle branch block. Combined with the medical history, the diagnosis was acute pulmonary embolism caused by long-term car riding, also known as "economy class syndrome."

In contrast, Ms. Liu, a 56-year-old female worker, is luckier. At about 8 a.m. on February 19, Ms. Liu returned to Gaobu Town, Dongguan City from Yongzhou, Hunan Province, after a 12-hour car ride. She fainted as soon as she got off the car. After the emergency personnel of Gaobu Hospital arrived at the scene, they quickly transferred her to Dongguan People's Hospital. The medical staff went all out to treat her. Pulmonary artery CTA indicated that there were multiple thrombotic occlusions in the main trunk and branches of her pulmonary artery. She was immediately given heparin anticoagulation and transferred to the interventional room to open the blood vessels. After local thrombolysis, the patient's blood pressure and oxygenation improved significantly. After returning to the emergency ICU, she continued to receive anticoagulation, respiratory support, and stable circulation treatment. At present, Ms. Liu has been successfully extubated from the ventilator, regained consciousness, and recovered well. She will be transferred out of the emergency ICU to the general ward for continued observation and treatment soon.

Prolonged sitting is a risk factor for acute pulmonary embolism

Any factors that can cause venous blood stasis, vascular endothelial damage and hypercoagulable state are risk factors for venous thromboembolism, including hereditary and acquired risk factors. Acquired risk factors refer to a variety of pathological and physiological abnormalities that are acquired after birth and are prone to venous thromboembolism, most of which are temporary or reversible, such as surgery, trauma, acute medical diseases (such as heart failure, respiratory failure, infection, etc.), and certain chronic diseases (such as antiphospholipid syndrome, nephrotic syndrome, inflammatory bowel disease, myeloproliferative diseases, etc.). In addition, paralysis, long-distance air or car travel, and home-based elderly care can lead to venous blood stasis and are prone to venous thromboembolism. The mortality and disability rates of pulmonary thromboembolism are very high. Recent international registration studies have shown that its 7-day all-cause mortality rate is 1.9%~2.9%, and its 30-day all-cause mortality rate is 4.9%~6.6%.

Strategies for the diagnosis of acute pulmonary embolism

The clinical manifestations of acute pulmonary thromboembolism lack specificity and are easily missed or misdiagnosed. The severity varies greatly, ranging from no symptoms in mild cases to hemodynamic instability or even sudden death in severe cases. Suspected patients should be examined based on the results of the clinical probability assessment, and once pulmonary embolism is confirmed, other potential risk factors should be further explored. The clinical manifestations of acute pulmonary thromboembolism are shown in Table 1. Table 1 Clinical manifestations of acute pulmonary thromboembolism

For cases with risk factors, especially those with multiple risk factors, a strong diagnostic awareness is required, and the following points should be paid attention to.

(1) Clinical symptoms and signs, especially unexplained dyspnea, chest pain, hemoptysis, syncope or shock in highly suspected cases, or accompanied by unilateral or bilateral asymmetric lower limb swelling and pain, are of great significance for diagnosis.

(2) Combined with basic examinations such as electrocardiogram, chest X-ray, and arterial blood gas analysis, PTE can be preliminarily suspected or other diseases can be excluded.

(3) It is advisable to perform routine D-dimer testing as soon as possible to make an exclusionary diagnosis.

(4) Ultrasound examination can obtain results quickly and can be performed at the bedside. Although it is generally not used as a diagnostic method, it is of great value in suggesting the diagnosis of pulmonary embolism and excluding other diseases. It should be listed as a priority examination item when pulmonary embolism is suspected. If evidence of deep vein thrombosis in the lower extremities is found at the same time, the possibility of diagnosis is further increased.

For patients suspected of acute pulmonary embolism, different diagnostic strategies are recommended depending on whether they have concurrent hemodynamic disorders (Figures 1 and 2).

Note: CTPA stands for CT pulmonary angiography Figure 1 Diagnostic process of high-risk pulmonary thromboembolism

Note: CTPA is CT pulmonary angiography; V/Q is pulmonary ventilation/perfusion; a is iodine allergy, renal insufficiency, and pregnant women. Figure 2 Diagnostic process of non-high-risk pulmonary thromboembolism

Acute pulmonary embolism is dangerous, prevention is very important

Acute pulmonary embolism has an acute onset and a rapid progression. It is one of the important causes of unexpected death. Prevention is extremely important, especially for high-risk groups. High-risk groups include: patients with fever, who are prone to hypercoagulable state. In addition, long-distance travel increases the risk of thrombosis. Fever symptoms may also aggravate dehydration, further increasing the risk of venous thromboembolism; patients with chronic diseases, such as tumors, heart failure, nephrotic syndrome, etc.; also pregnant women, long-term oral contraceptive users, the elderly, obese people, etc.

When traveling long distances, it is recommended to do the following things.

(1) Drink plenty of water. Especially when you are often in an air-conditioned environment, the most important thing is to replenish water. It is best to drink 200 ml of water every hour to reduce blood viscosity, but avoid drinking alcohol or large amounts of coffee.

(2) Move more. Try to avoid sitting in the same position for a long time. You can move your feet or legs regularly. It is recommended to do 3 to 5 minutes of foot exercises every hour, including toe, toe and knee exercises, to promote blood circulation. In places with limited space such as airplanes, trains, and cars, you can walk around and do leg stretching exercises when conditions permit.

(3) Wear loose clothes. Avoid wearing socks and pants that are too tight, which is beneficial to the return of venous blood in the lower limbs. You can also wear low-knee elastic socks to prevent venous blood stasis and allow blood to return to the heart better.

In addition, routine physical examinations can be done on weekdays, and simple blood tests and imaging examinations can be used to detect or prevent thrombosis in a timely manner. Through medical evaluation, people with risk factors for clotting can take preventive measures when traveling long distances, such as wearing medical elastic stockings, increasing walking, etc., and taking preventive medications as prescribed by doctors when necessary.

References

[1] Chinese Society of Cardiology, Chinese Medical Association Cardiovascular Disease Branch, Chinese Medical Association Cardiovascular Physicians Branch Pulmonary Vascular Disease Group, Chinese Pulmonary Embolism Treatment Team Alliance. Chinese expert consensus on multidisciplinary team treatment of acute pulmonary embolism [J]. Chinese Journal of Cardiology, 2022, 50(1): 25-35.

[2] Pulmonary Embolism and Pulmonary Vascular Disease Group of the Chinese Society of Respiratory Medicine, Pulmonary Embolism and Pulmonary Vascular Disease Working Committee of the Chinese Medical Association Respiratory Physicians Branch, National Pulmonary Embolism and Pulmonary Vascular Disease Prevention and Control Collaboration Group. Guidelines for the diagnosis, treatment and prevention of pulmonary thromboembolism [J]. Chinese Medical Journal, 2018, 98(14): 1060-1087.