Prevent pulmonary embolism after childbirth

This is the 3542nd article of Da Yi Xiao Hu

A healthy baby was born three days ago, and the whole family was so happy. Xiao Zhang got up early in the morning and dressed herself up. She felt weak in the past few days after giving birth and did not get out of bed to move around much. Today she was going to be discharged from the hospital, so she combed her hair and dressed up.

Xiao Zhang had just finished using the bathroom and was combing her hair in front of the mirror when she suddenly felt chest tightness and pain and fell to the ground involuntarily. A fellow patient nearby heard the noise and hurried over. He saw Xiao Zhang being helped to the bed while calling for the nurse. The doctors and nurses rushed into the ward immediately, giving Xiao Zhang oxygen while measuring his blood pressure. The monitor was also brought in quickly, and after connecting the finger pulse oxygen, the oxygen saturation was less than 90%. The doctor on duty realized the severity of the condition and immediately called the ICU doctor for consultation.

Doctor Sheng from the ICU came in a hurry, bringing a portable ultrasound with him. We have mentioned before that ultrasound is a powerful weapon in the hands of ICU doctors. If it were not too large, they would want to carry it in their pockets every day like a stethoscope. While comforting the parturient, Doctor Sheng took out a stethoscope to auscultate the lungs. The breathing sounds were fine, and there was no problem. The blood pressure was normal except for a faster heartbeat on the monitor. It was time to send ultrasound. Doctor Sheng took out the ultrasound probe and immediately performed an ultrasound examination on Xiao Zhang at the bedside. The left heart was normal and the pulsation was strong; the right heart was enlarged, and the two ventricles were almost the same width. Seeing this, Doctor Sheng had an idea in mind, and changed to a high-frequency ultrasound probe to check the blood vessels of the parturient's lower limbs, and found a long blood clot in the femoral vein of the right lower limb. The mystery was solved. The culprit that caused Xiao Zhang's sudden chest tightness was acute pulmonary embolism!

Xiao Zhang felt very confused. He was in good health. How could he have pulmonary embolism? There are many kinds of emboli that can block the pulmonary artery, such as fat, cancer embolism, air, amniotic fluid, etc., but the most common one is pulmonary thromboembolism. It is a blood clot originating from the veins of the lower limbs or pelvis. After entering the pulmonary artery through the right atrium and right ventricle along the blood flow, it blocks the larger pulmonary artery branches, hinders pulmonary blood flow, and then affects the patient's respiratory and circulatory function. Acute pulmonary embolism is the third most common cause of death from cardiovascular disease in the world, second only to coronary heart disease and stroke. Acute pulmonary embolism is an important cause of maternal death, with an incidence rate of up to 1/6400 during pregnancy, and 15 times higher after delivery than before delivery.

During pregnancy, the enlarged uterus compresses the abdominal veins, causing obstruction of blood return and varicose veins in the lower limbs and pelvis. During pregnancy, due to the effect of progesterone, the blood is in a hypercoagulable state, making it easy for venous thrombosis to form in the lower limbs and pelvis. In addition, bed rest after delivery increases the risk of deep vein thrombosis and acute pulmonary embolism.

"Do you want to draw blood to check the D-dimer?" asked the intern Xiao Liu. There are many factors that cause the D-dimer level to rise in hospitalized patients. For example, pregnancy itself can be accompanied by an increase in this indicator. D-dimer cannot diagnose pulmonary embolism. The gold standard for diagnosing acute pulmonary embolism is enhanced CT pulmonary angiography. In addition, ultrasound can also help diagnose pulmonary embolism. The patient's lung breath sounds were normal, and no abnormalities were found in the lung ultrasound. Proximal deep vein thrombosis was found in the lower limbs. Combined with the patient's symptoms and echocardiography, the accuracy of acute pulmonary embolism can reach more than 90%. Doctor Sheng said confidently.

"How should my pulmonary embolism be treated? I don't need surgery, right?" Xiao Zhang now felt that his chest tightness was better, and he lifted the oxygen mask to ask the doctor worriedly. Acute pulmonary embolism is divided into three levels: high risk, medium risk, and low risk. High risk refers to pulmonary embolism combined with hypotension and shock. Such patients often need to actively take thrombolytic therapy, which is to inject thrombolytic drugs intravenously to dissolve the blood clots in the pulmonary arteries. For pregnant women, due to the possibility of bleeding complications, it is only recommended for life-threatening pulmonary embolism. Xiao Zhang's blood pressure is good, but his right heart function is abnormal and his breathing is affected. He is a medium-risk patient and only needs anticoagulant therapy. Of course, there is no need to consider interventional and other surgical treatment options.

In Xiao Zhang's case, it is only necessary to give low molecular weight heparin subcutaneously twice a day, and then transition to oral warfarin. Warfarin is a vitamin K antagonist with an anticoagulant effect. Because it can cross the placenta and has risks such as teratogenicity, it cannot be used by pregnant women. However, it does not enter breast milk, so it can be used for breastfeeding mothers. Note that neither pregnant women nor mothers who need to breastfeed can use new oral anticoagulants such as rivaroxaban, dabigatran, etc.

Although most cases of acute pulmonary embolism can be relieved in about a week, it is not the end of the story. Mothers still need to take warfarin for at least 3 months to prevent recurrence of pulmonary embolism. Here we also remind pregnant women to pay attention to moving their lower limbs more, especially after giving birth, and walk more instead of staying in bed for the whole month.

Author: Songjiang Hospital Affiliated to Shanghai Jiaotong University School of Medicine

Emergency Critical Care Department

Li Xiangying Wang Xuemin

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