What Is Aspiration Pneumonia?

Aspiration pneumonia refers to chemical pneumonia caused by accidental inhalation of acidic substances, such as animal fats, food, stomach contents and other irritating liquids and volatile hydrocarbons. In severe cases, respiratory failure or respiratory distress syndrome can occur. .

Basic Information

English name: Aspiration Pneumonia
Visiting department: Pediatrics, Respiratory
Multiple groups: child
Common locations: Lungs

Common causes: Caused by accidental inhalation of acids and other irritating liquids and volatile hydrocarbons
Common symptoms: Laryngeal reflex spasm and wheezing cough, spasmodic cough with shortness of breath, body temperature, high fever, wet lungs and wheezing, severe hypoxemia, respiratory distress sign

Causes of aspiration pneumonia

Clinically the most common is the inhalation of gastric contents by mistake, a lung infection caused by gastric acid stimulation. Kerosene, gasoline, dry cleaning agents, furniture polishes, etc. can sometimes be inhaled by mistake and are more common in children. In normal people, due to the synergistic effect of the protective reflex of the larynx and swallowing, general food and foreign bodies do not easily enter the lower respiratory tract. Even if a small amount of liquid is accidentally sucked, it can be discharged through coughing. General anesthesia, cerebrovascular accidents, seizures, alcoholism, anesthesia, or sedation, patients with weakened or disappeared defenses can inhale the foreign body; tracheoesophageal fistula caused by various reasons, food can also enter directly through the esophagus Intratracheal; iatrogenic factors such as gastric tube irritation of the pharynx cause vomiting; tracheal intubation or tracheotomy affects laryngeal function, inhibit normal pharyngeal movements can suck vomitus into the airway. Elderly people are less responsive and are more prone to aspiration pneumonia.

Neonatal aspiration pneumonia

Inflammation of the lungs caused by the inhalation of foreign bodies (usually amniotic fluid, meconium, and milk) through the airways of the fetus or newborn during intrauterine, during labor, or after birth. It is one of the common and frequently-occurring diseases in the early neonatal period and has a high mortality rate. Neonatal aspiration pneumonia often occurs in newborns with perinatal fetal distress or asphyxia. Such children have a long delivery process during delivery, and placental or umbilical cords affect fetal blood circulation and cause intrauterine hypoxia. , Stimulate the fetal respiratory center excitement, wheezing breathing occurs, causing amniotic fluid or meconium aspiration. There are also a small number of children due to inhaled milk due to improper feeding. The caesarean newborn's mouth is not squeezed by the birth canal, and the amniotic fluid content of the respiratory tract is more than that of natural delivery. If the respiratory tract is not cleaned thoroughly, the newborn will breathe earlier and the chance of neonatal aspiration pneumonia will be increased.

2. Pediatric milk aspiration pneumonia

More common in children with swallowing disorders, esophageal deformity, esophageal insufficiency, severe cleft palate, rabbit lips and other diseases.

Clinical manifestations of aspiration pneumonia

The clinical manifestations are related to the inducing factors and the state of the body, but they are different in severity. However, if the inducing factors cannot be removed in time, thorough treatment is difficult and recurrent attacks are likely. Inhalation of vomitus can cause sudden laryngeal reflex spasm and bronchial irritation with wheezing cough. Aspiration pneumonia caused by esophageal and bronchial fistulas, with spastic cough and shortness of breath after eating every day; people with unconsciousness often have no obvious symptoms after inhalation, but after 1 to 2 hours, they may suddenly have difficulty breathing, cyanosis, and often cough. It produces serous foamy sputum, which can carry blood. High and medium fever can occur. Wet and wheezing sounds can be heard in both lungs, severe hypoxemia can occur, acute respiratory distress syndrome (ARDS) can occur, and can be accompanied by carbon dioxide retention and metabolic acidosis.

Aspiration pneumonia test

The white blood cell count can be normal or high on a routine blood test; chest X-rays can be seen 1 to 2 hours after inhalation, and the two lungs can be scattered with irregular flaky edges and blurred shadows. The distribution of intra-pulmonary lesions is related to the position at the time of absorption. Lower lung lobe, right lung is more common. If pulmonary edema occurs, the flaky, cloud-like shadows appearing in the two lungs merge into a large piece, spreading outward from the hilars of the two lungs, and the inner band of the two lungs is obvious.

Aspiration pneumonia diagnosis

For people with high risk factors for aspiration, sudden irritating cough, sputum, dyspnea or respiratory failure, or recurrent fever, should be considered aspiration pneumonia, combined with chest imaging examination, to make the diagnosis easier.

Aspiration pneumonia treatment

In an emergency, high concentration oxygen inhalation should be given immediately, and the back should be patted in time to encourage the patient to cough; conditions permit the use of fiberoptic bronchoscopy or tracheal intubation to suck out foreign bodies. Antibiotics are only used to control secondary infections, and are not recommended. For the prevention of bacterial infections, the use of drugs can not reduce the occurrence of secondary bacterial infections, and it is easy to produce drug-resistant strains.

Patients with aspiration pneumonia outside the hospital generally have anaerobic infections. Aspiration pneumonia in the hospital generally involves a variety of microorganisms, including Gram-negative bacilli, Staphylococcus aureus, and anaerobic bacteria. For anaerobic infection, clindamycin is commonly used as a drug, and metronidazole can be used in combination with clindamycin. Most broad-spectrum antibiotics are also effective against anaerobic infections. The empirical use of antibiotics in critical cases is aminoglycosides or ciprofloxacin in combination with one of the following drugs: 3rd generation cephalosporins, imipenem, penicillin resistant to pseudomonas or -lactam- -lactamase inhibitor. Patients who are allergic to penicillin can choose aztreonam and clindamycin.

Lower respiratory tract mechanical obstruction can be caused by inhalation of neutral liquids or particulate matter (such as drowning, severe unconscious patients can inhale non-acidic stomach contents or fed food, etc.). Such patients need to be intubated immediately for adequate suction.

Aspiration pneumonia prevention

The main measures to prevent aspiration pneumonia are to prevent the inhalation of food or stomach contents. For example, the stomach should be emptied before anesthesia. For patients with coma, head down and lateral position should be used. Gastric tubes should be placed as soon as possible, and tracheal intubation should be performed if necessary. Or tracheostomy. Strengthening care is more important.