Some post-operative patients and their families have some questions about post-operative pleural effusion, so we take time to talk about the situation of post-operative pleural effusion in precardiac disease. In fact, the incidence of postoperative pleural effusion in precardiac disease is relatively low and special, to be clear about the problem, we must first figure out what is pleural effusion.
In normal people, there is 3-15 ml of fluid in the pleural cavity, which plays a lubricating role during respiratory movements, but the amount of fluid in the pleural cavity is not fixed. Even in normal people, 500 to 1000 ml of fluid is formed and absorbed every 24 hours. The fluid in the pleural cavity is reabsorbed from the venous end of the capillaries, while the rest of the fluid is recycled to the blood by the lymphatic system, so that filtration and absorption are in a dynamic balance. If this dynamic balance is disrupted by systemic or local lesions, resulting in rapid formation or slow absorption of fluid in the pleural cavity, clinically a pleural effusion (Pleural effusion) will result. One may wonder, what is the pleural cavity? There is a potential cavity between the dirty layer of the pleura and the wall layer, and this cavity is called the pleural cavity. Li Pingyuan, Department of Pediatric Cardiac Surgery, Fu Wai Hospital, Beijing, China
Diagram of pleural cavity
So the question is, under what circumstances will pleural fluid increase? In other words, what are the causes of pleural effusion?
Generally, the pleural effusion you hear the most is likely to be like this: hearing that someone has tuberculosis and after a while says that there is pleural effusion, or someone has lung cancer and after a while says that there is pleural effusion, and so on similar cases, so there are many causes of pleural effusion, which are roughly summarized as follows.
I. Increased hydrostatic pressure in the pleural capillaries
Such as congestive heart failure, constrictive pericarditis, increased blood volume, and obstruction of the superior vena cava or the odd vein, which can produce pleural leakage.
Second, increased permeability of pleural capillaries
Such as pleural inflammation (tuberculosis, pneumonia), connective tissue disease (systemic lupus erythematosus, rheumatoid arthritis), pleural tumor (mesothelioma), pulmonary infarction, subphrenic inflammation (subphrenic abscess, liver abscess, acute pancreatitis), etc. will produce pleural exudate.
Third, decreased colloid osmotic pressure in the pleural capillaries
such as hypoproteinemia, liver cirrhosis, nephrotic syndrome, acute glomerulonephritis, mucinous edema, etc., produce pleural leakage.
IV. Mural pleural lymphatic drainage disorder cancer
Lymphatic duct obstruction, abnormal developmental lymphatic drainage, etc., producing thoracic exudate.
V. Intrathoracic hemorrhage due to injury
Aortic aneurysm rupture, esophageal rupture, thoracic duct rupture, etc. will produce hemothorax, pus thorax, celiac thorax.
Ladies and gentlemen, have you been confused by the names of leaking fluid and exudate? Here comes the question, people will ask: Dr. Li, you introduced in such detail, yet we still can’t figure it out. Yes, we started with a big article, just to throw a brick to give you a basic knowledge, so now back to the topic, let’s talk about the matter of postoperative pleural effusion in precordial disease.
Some children with precordial disease have more or less chronic cardiac insufficiency or chronic heart failure before surgery, such as progressive exertional dyspnea, telescopic breathing, nocturnal paroxysmal dyspnea, peripheral edema, jugular venous anger, bilateral pulmonary rales, etc. When the child is operated, some children with poor recovery of cardiac function will develop pleural effusion, often bilateral, as a leaky fluid. It is usually seen in children with left heart failure in the early stage and right heart failure in the later stage. The purpose is to increase the contractility of the heart muscle, protect the heart muscle and correct the heart failure, and at the same time, oral diuretics and potassium supplements are used to increase the fluid outflow and prevent the occurrence of pleural effusion.
Figure shows pleural effusion
So, what kind of congenital disease is prone to pleural effusion?
Complex cyanotic congenital heart disease is prone to pleural effusion after surgery. For example, tricuspid atresia, or multiple complex congenital heart diseases with only one functioning ventricle, often result in pleural effusion after surgery, and was named the “Fontan procedure” after Fontan et al. first reported the successful treatment of tricuspid atresia with the Fontan procedure in 1971. The Fontan procedure is a palliative procedure based on the bidirectional Glenn procedure, in which venous blood from the body circulation is diverted directly into the pulmonary artery without passing through the right ventricle, thereby separating the body and pulmonary circulations and reducing the load on the left ventricle. Currently, extracardiac total vena cava-pulmonary artery anastomosis is the best option.
1.Bidirectional Green’s surgery: For children with young age and unsatisfactory pulmonary vascular development, the bidirectional Green’s surgery (superior vena cava-pulmonary artery connection) is performed first to improve hypoxia, promote pulmonary vascular development, and reduce ventricular load, and then complete the second-stage total vena cava-pulmonary artery connection for children who meet the conditions.
2.Total vena cava pulmonary artery connection: connect all the upper and lower vena cava with pulmonary artery, and for children with deviations in pulmonary vascular development, open window surgery can be performed at the same time.
After reading this, I think all the patients are still confused because sometimes even the cardiac surgeons who have been working for more than 10 years are confused about these procedures for complex congenital heart disease, let alone the patients. It doesn’t matter, all you need to know is that patients with total vena cava anastomosis are most likely to have pleural effusions after surgery.
The incidence of pleural effusion after Fontan surgery is 15-45%. prolonged pleural exudation causes massive loss of lymphocytes and plasma proteins, leading to decreased cellular and humoral immunity, increasing the chance of postoperative infection and prolonging hospitalization. the causes of intractable pleural effusion after Fontan surgery are not well understood, and according to studies in the literature, there are several causes.
1, older age at surgery: with age, the volume load of the heart increases, myocardial contractility and cardiac compliance decreases, and the atrial pressure rises leading to obstruction of pulmonary venous return; with the volume load of the heart increases, the heart enlarges, and the atrioventricular valve annulus deformation causes incomplete closure of the atrioventricular valve, leading to a rise in atrial pressure leading to obstruction of pulmonary venous return; with age, hypoxia increases, and the collateral vessels between the main pulmonary arteries increase This leads to an increase in pulmonary artery blood flow and ventricular volume load, resulting in an increase in pulmonary artery pressure.
2.Low Nakata pulmonary artery index: Nakata pulmonary artery index less than 250 mm2/m2 indicates poor pulmonary vascular development, which is a high risk factor for Fontan surgery. low Nakata value often indicates elevated pulmonary venous pressure and obstruction of systemic lymphatic return after Fontan surgery, so the incidence of pleural fluid, ascites and pericardial effusion is high.
3, prolonged extracorporeal circulation and aortic block: extracorporeal circulation > 120 min and aortic block > 60 min indicate that the likelihood of pleural effusion after Fontan surgery is greatly increased, which has been confirmed by many expert studies, because prolonged extracorporeal circulation can damage the integrity of capillaries and lead to “capillary leak syndrome”. This damage is exacerbated by the increase in venous pressure after the Fontan procedure, which leads to the development of intractable pleural effusions. The prolonged aortic blockade causes massive necrosis of cardiomyocytes, which severely impairs myocardial contractility and ventricular compliance, resulting in a significant increase in venous pressure and an increased likelihood of pleural effusion.
At the initial stage of pleural effusion, the effect on the human body is not obvious, and many patients have no conscious symptoms, but if they really feel discomfort, then the disease has already developed to a certain extent. The common symptoms are generally the following.
1, cough: patients will be accompanied by chest pain when coughing hard, and serious patients will feel chest tingling when breathing deeply.
2. Difficulty in breathing: A small amount of pleural effusion does not cause breathing problems and may cause chest tightness. However, when the fluid accumulation reaches a certain amount, there may be obvious difficulty in breathing, at which time the above-mentioned chest pain may be relieved to some extent.
3.Symptoms of the whole body: Different types of pleural effusion will have different symptoms of the whole body. Here we will only talk about pleural effusion after preoperative surgery: it is manifested as dyspnea, shortness of breath, swelling of the face, fast breathing, purple lips, children crying and irritability and other abnormalities.
4.Examination abnormalities: pleural friction sounds can be heard in a small amount of effusion, typical signs of effusion with fullness of the affected side of the thorax, reduced respiratory motion, turbid percussion, diminished or absent fibrillation and breath sounds, bronchial breath sounds can sometimes be heard at the upper edge of the percussion turbid boundary in a medium amount of effusion, and the trachea is displaced to the healthy side in a large amount of effusion.
The picture shows the radiographic manifestation of pleural effusion.
If a small amount of pleural effusion cannot be released, it can be treated conservatively: strictly control the amount of water intake, strengthen diuresis, and make sure not to overfeed the child and drink too much water.
The amount of effusion less than 200 ml can be asymptomatic , moderate or large amount of effusion when the child (person) can appear respiratory distress, can be used erythromycin pleural injection of pleural fixation, relative to other methods, pleural fixation has the advantages of small trauma, safe, simple, repeatable operation, etc., relative to other drugs such as talc, tetracycline, erythromycin is inexpensive, small side effects, wide range of sources, more suitable for children. Since pleural fixation is performed to close the chest cavity through a sterile inflammatory response, analgesia is the key to successful operation when performing pleural fixation. When pleural effusion is large, erythromycin is diluted and single pleural fixation may not be ideal, multiple pleural injections (usually at intervals of about 3 days) and gradually increasing the dose of erythromycin can eventually cure pleural effusion in most patients.
Figure shows the drainage of pleural effusion in children after atrial tamponade
Other types of pleural effusion, such as
1. postoperative pleural rupture, resulting in the inflow of fluid from the pericardium into the thoracic cavity and the formation of pleural effusion, which can be resolved by a one-time effusion puncture.
2. Patients with unclosed arterial duct ligation may injure the thoracic duct during surgery and form celiac disease. After surgery, it is necessary to abstain from food containing high fatty substances, drainage, and if necessary, reoperation.
3. Rupture of lung tissue, infection, exudation, etc.
According to the above description, there are three kinds of postoperative pleural effusion after congenital heart disease:
First, pleural effusion caused by heart failure, which can be cured by cardioplegia, diuresis, potassium supplementation and fluid puncture and drainage.
Second, congenital complex cyanotic heart disease, pleural effusion after total vena cava surgery, usually celiac fluid, can be treated by a combination of measures such as drainage, diuresis, diet control, reduction of fatty food intake, and intra-thoracic injection of certain thoracic adhesives. Of the three conditions, this type of pleural effusion is the most difficult, prolonged and costly to treat. If you have patients and family members with this disease, you must be fully prepared. If the pleural effusion or abdominal effusion does not heal, it means that the disease is at an advanced stage and that there is really nothing that can be done. The good news is that the incidence of this is relatively low. The bad news is that once the pleural effusion is bad for a long time, it means that the prognosis is not good.
Third, other causes of pleural effusion, through effusion puncture, drainage, fasting, if necessary, according to the condition of the second surgical treatment.
Well, all patients, to summarize, the incidence of pleural effusion after congenital heart disease surgery is relatively low. Even if it happens, the corresponding treatment means are perfect and there are many measures, most of them can be recovered and cured. Well, see you next time if you have any questions!
This article is authorized by Dr. Li Pingyuan.