pregnancy asthma
Introduction
Introduction to pregnancy asthma The incidence of pregnancy-induced asthma is about 1% to 4%. In patients with 1/3 pregnancy-induced asthma, asthma may be aggravated. A small number of patients affect the mother and the fetus. For pregnancy-induced asthma, the state of the disease should be closely observed in the early stages of pregnancy. Avoid acute episodes, so clinicians should be familiar with and understand the interactions between asthma and pregnancy and the treatment characteristics of the disease. basic knowledge Sickness ratio: 0.0001% Susceptible population: pregnant women Mode of infection: non-infectious Complications: premature birth
Cause
Causes of pregnancy asthma
(1) Causes of the disease
1. Physiological changes during pregnancy, due to increased blood flow in the uterus and placenta, increased oxygen consumption, increased secretion of estrogen and other factors can cause tissue mucosal congestion, edema, capillary congestion, mucous gland hypertrophy, so 30% pregnancy Women with rhinitis-like symptoms, can also show nasal obstruction, nosebleed, pronunciation changes and other symptoms, with the increase of the uterus, abdominal expansion, abdominal anteroposterior diameter, lateral mobility is limited; hormone release during pregnancy can make the chest wall Changes in elasticity, changes in the effects of the transverse and chest wall caused by pregnancy cause changes in lung function.
2. Changes in lung function Pregnancy can lead to changes in the parameters of ventilation and gas measurement associated with asthma. There are differences in volume and flow, but in general, there is not much reduction in lung capacity. Differences in gas measurement and progesterone acting on the respiratory center. Level-related, hyperventilation, increased gas flow rate and constant frequency, PaCO2 can be decreased or increased, and pH remains unchanged due to increased renal bicarbonate excretion.
(two) pathogenesis
The exact mechanism of the course of pregnancy asthma is still unclear. Data analysis of 1087 pregnant asthma patients found that 36% of asthma improved, 23% worsened, and 41% did not change, suggesting that pregnancy asthma can be affected by multiple factors.
1. Factors that can worsen asthma
(1) Competitive binding of prostaglandins, aldosterone or deoxycorticosterone to the glucocorticoid receptor results in decreased lung reactivity to the cortex.
(2) Prostaglandin F2a-mediated bronchoconstriction.
(3) The concentration of the main basal protein in the placenta of the lung is increased.
(4) A viral or bacterial respiratory infection triggers asthma.
(5) Gastroesophageal reflux induced asthma.
(6) Changes in functional residual capacity and changes in ventilation/perfusion ratio.
(7) Increased stress.
2. Factors that can improve asthma
(1) Progesterone mediates bronchodilation.
(2) Estrogen or progesterone can mediate the enhancement of -adrenal bronchodilation.
(3) Lower plasma histamine levels, thereby reducing bronchoconstriction caused by it.
(4) Increase in serum free cortisol hormone.
(5) Glucocorticoid-mediated increase in beta adrenal receptor reactivity.
(6) Prostaglandin E-mediated bronchodilation.
(7) Prostaglandin I2-mediated bronchial stabilization.
(8) Increased half-life or decreased protein binding rate of endogenous or exogenous bronchodilators.
Prevention
Pregnancy asthma prevention
1. Educate pregnant women and their families about the importance of asthma management during pregnancy.
2. Dynamic monitoring of PEF during pregnancy, at least once a day (such as 6 to 7 in the morning), and record the asthma diary to assess changes in asthma.
3. Based on the clear allergens, efforts to avoid exposure to various factors that may induce (promoting) asthma.
Complication
Pregnancy asthma complications Complications
Can lead to premature birth, fetal dysplasia.
Symptom
Pregnancy Asthma Symptoms Common Symptoms Pronunciation Change Nasal Bleeding Hypertension Pre-eclampsia Toxic Vaginal Bleeding
1.30% of pregnant women have rhinitis-like symptoms
It can also show symptoms such as nasal obstruction, nosebleed, and pronunciation change. As the uterus increases, the abdomen expands, the anteroposterior diameter of the abdomen increases, and the lateral mobility is limited. The release of hormones during pregnancy can change the elasticity of the chest wall.
2. The effect of asthma on pregnancy
Repeated asthma attacks can have adverse effects on pregnancy. It can cause premature birth, fetal dysplasia, fetal growth retardation, expired birth, low body weight, etc. for pregnant women; pre-eclampsia, pregnancy-induced hypertension, pregnancy toxemia, vagina Bleeding and dystocia, etc., may even pose a threat to the lives of mothers and babies. Studies suggest that these risk factors are related to the severity of asthma attacks, but under strict observation and effective treatment, asthma patients have no risk of childbirth. Normal pregnant women are high, and if asthma is well controlled, it will not increase the risk of perinatal and childbirth, nor will it have adverse consequences for the fetus.
3. The effect of pregnancy on asthma
The effect of pregnancy on asthma, several studies reported that in pregnancy, about 1/3 of patients aggravated, 1/3 of asthma patients reduced severity, l / 3 patients did not change their condition, asthma during pregnancy, especially pregnancy asthma increased Women, sudden acute exacerbations of their condition are often prone to 24-36 weeks of gestation, and asthma usually has very few episodes during childbirth.
Examine
Examination of pregnancy asthma
Blood eosinophils are usually above 6%.
Most of the chest X-rays have no special findings.
Diagnosis
Diagnosis of pregnancy-induced asthma
diagnosis
According to the history of pregnancy, medical history and clinical symptoms can be diagnosed.
Differential diagnosis
Cardiogenic asthma
Cardiac asthma is common in left heart failure, and the symptoms at the time of onset are similar to those of asthma, but cardiogenic asthma has many other history and signs such as rheumatic heart disease and congenital heart disease.
Coughing, coughing out of pink foam, the lungs can smell a wide range of blisters and wheezing sounds, the left heart is enlarged, the heart rate is increased, and the apex can be heard.
Chest X-ray examination, visible heart enlargement, pulmonary congestion, cardiac B-ultrasound and cardiac function tests help to identify.
If it is difficult to identify a nebulizable selective 2 receptor agonist or a small dose of aminophylline to relieve symptoms after further examination, avoid epinephrine or morphine to avoid danger.
2. Tuberculosis
There is a history of contact with tuberculosis, and symptoms of chronic poisoning of tuberculosis occur.
The tuberculin test was positive for the PPD test, while the bronchial challenge test was negative or the PEF mutation rate was <15%.
The sputum smear was found to be acid-fast bacilli, and the Mycobacterium tuberculosis polymerase chain reaction (TB-PCR) was positive.
Chest X-ray, chest CT examination, and fiberoptic bronchoscopy if necessary.
3. Capillary bronchitis
Mostly caused by respiratory syncytial virus, more common in infants under 3 years old, especially under 6 months, no recurrent episodes.
Inhaled 2 receptor agonists and systemic use of hormones are not effective.
The main signs: acute onset, first symptoms of upper respiratory tract infection, gradually appearing wheezing, expiratory breathing difficulties, prolonged exhalation, expiratory breath sounds and fine wet voice.
Chest X-ray: diffuse emphysema and patchy shadows.
4. Mycoplasma pneumoniae
Performance: irritating dry cough, no obvious breathing difficulties, symptoms can last for 2 to 3 months.
The main identification points:
No repeated cough, history of asthma, respiratory symptoms of nasal congestion and other symptoms, and then coughing and prolonged.
Chest radiographs have migratory patchy or cloud-like shadows that are effective for macrolide antibiotic treatment.
The condensation set test is 1/64 positive or positive for Mycoplasma pneumoniae antibody.
