What is Foreign Body Aspiration?
Children swallowing or inhaling foreign objects is a major reason behind children’s deaths due to the structure and development of their bodies. Foreign object inhalation, commonly known as choking, happens when an object enters the breathing or digestive tract and blocks the airflow. This blockage could lead to breathing problems and insufficient oxygen supply to the body, leading to severe harm or even death.
The items that children commonly choke on include food, coins, toys, and balloons. When unable to breathe, the primary cause of death is typically due to the brain not receiving enough oxygen (hypoxic-ischemic brain injury). More rarely, it might be due to bleeding in the lungs (pulmonary hemorrhage).
What Causes Foreign Body Aspiration?
Objects that children often swallow by accident usually include food, coins, toys, and balloons. This can happen more frequently in children due to their habit of exploring the world around them by putting things in their mouths.
Risk Factors and Frequency for Foreign Body Aspiration
In 2016, the rate of fatal choking in American children under 5 years old was 0.43 per 100,000 according to the National Safety Council. However, a study found that non-fatal choking rates in children below 14 were a lot higher, at 20.4 per 100,000. More than half (55.2%) of these non-fatal cases in children younger than 4 years involved candy, while hot dogs and nuts often resulted in hospitalization. Boys made up slightly over half (55.4%) of the cases, but there wasn’t a notable difference between boys and girls. The data shows that the frequency of aspirated coins (coins being inhaled into the lungs) has dropped, but jewelry being aspirated is becoming more common in the US. Despite these trends, the overall rate of cases from foreign body aspiration that ended up in the emergency department has not changed much from 2001 to 2014.
- Studies beyond the U.S have found that around 60% of patients who have inhaled foreign objects are male.
- Nuts are responsible for about 40% of these cases in high-income and low-middle income countries.
- Regarding inorganic foreign objects, magnets were found to be the cause in 34% of the cases based on studies from high-income countries.
- In these magnet-related cases, diagnosis was delayed by more than 24 hours in about 60% of them.
Signs and Symptoms of Foreign Body Aspiration
People who have aspirated something might not show any obvious symptoms. In many instances, this only gets discovered during a medical examination or when discussing medical history. However, common symptoms that may occur suddenly include coughing, choking, and difficulty breathing. One study found these symptoms were 91.1% sensitive and 45.2% specific in indicating such an event. Wheezing, which is a symptom doctors can detect by listening to the respiratory sounds of a patient, was found in 60% of cases in the same study, and uneven breathing sounds were found in 32% of patients. A change in the regular physical examination can correctly identify someone with a foreign object in their respiratory tract about 80.4% of the time and correctly excludes those who do not have foreign body aspiration about 59.5% of the time.
Testing for Foreign Body Aspiration
Doctors often use chest X-rays as an initial method to check for foreign body aspiration, which is when an object is breathed into the airways. Typical chest X-ray findings that suggest aspirated foreign bodies include collapsed lung (atelectasis), punctured lung (pneumothorax), and air trapping. However, many cases have normal chest X-rays, with one study indicating normal results in 35% of cases. This study also found that the most common abnormality, present in 53% of cases, was air trapping. Regarding its accuracy, chest X-rays have shown a sensitivity (correctly identifying those with the condition) of around 67.9% and a specificity (correctly identifying those without the condition) of about 71.4%. Importantly, a single X-ray or piece of information usually can’t definitely confirm an aspiration; it is often necessary to use a bronchoscope, a device to view inside the airways, for direct identification.
One proposed plan for diagnosing foreign body aspiration using different imaging techniques involves starting with frontal and side X-rays of the chest, along with neck X-rays if required by physical exam. If these X-rays show abnormalities, the next step is bronchoscopy. However, if the X-rays don’t provide enough information in a patient showing symptoms and with a history suggesting foreign body aspiration, a chest CT scan is recommended. If CT is not an option, and the child is older than 5 years, doctors can use X-rays that take images as the patient breathes in and out. For children under 5, X-rays taken with the patient lying on their side are preferred. Fluoroscopy and MRI can be considered additional tools. This approach was developed at a certain medical center and isn’t universally accepted.
To reduce the need for CT scans, one study proposed a new method to increase the ability of X-rays to detect foreign bodies, especially those that don’t block X-rays (“radiolucent”). The method involves comparing the X-ray density of the affected lung to the opposite lung, with a higher ratio in patients who have aspirated a foreign body versus healthy individuals. They suggest that a ratio over 1.10 should lead to further investigation with a bronchoscopy, while a lower ratio should result in further tests with a CT scan. Since this method hasn’t been widely studied, more research is needed to confirm its effectiveness.
Treatment Options for Foreign Body Aspiration
The definitive way to diagnose and treat a foreign body, typically something inhaled into the airway, often involves a procedure called a bronchoscopy, where doctors use a special instrument to view the airways and remove the object causing the problem. However, there’s no one-size-fits-all approach to this.
One type of bronchoscopy, called rigid bronchoscopy, has several advantages over the other version called flexible bronchoscopy. Rigid bronchoscopy allows doctors to provide ventilation (supply air or oxygen) through the instrument, offers a clearer view with a solid telescope, and can accommodate retraction tools of various sizes. Additionally, because the rigid scope is wider, it’s easier to manipulate and remove the object without obstructing the vocal cords area (glottis). However, there are times when a flexible bronchoscopy might be the better choice, such as when the doctor suspects recurring pneumonia without a clear history of something being inhaled.
According to one study, the chance of finding a foreign body in the airway increased to 91% when three or more distinct signs and symptoms were present. Symptoms that significantly correlated with a foreign body being present included a history of sudden choking, turning blue (cyanosis), shortness of breath (apnea), and decreased lung sounds. Radiological images showing lung collapse (atelectasis), movement of the heart and other organs towards the space left by the collapsed lung (mediastinal shift), or signs of trapped air in the lungs also hinted at a foreign body present.
When these signs and symptoms were absent, it was very likely that the flexible bronchoscopy would not reveal a foreign body. In such cases, it’s safe to have these patients come back for a follow-up rather than undergoing an immediate bronchoscopy.
What else can Foreign Body Aspiration be?
Sometimes, objects that have been swallowed or inhaled and get stuck in the upper part of the windpipe, or trachea, can be misdiagnosed as viral croup. This is because an object blocking the airway can cause stridor, a high-pitched, wheezing sound caused by disrupted airflow. It’s not uncommon for this sound to be mistaken for the symptoms of croup, which also includes stridor.
Young children who have swallowed an object that gets stuck in their food pipe, or esophagus, may also experience stridor. This could happen because the object puts pressure on the nearby windpipe.
If the swallowed or inhaled object remains in the body for a long time, it could become a hotbed for recurrent lung infections. Conditions like asthma or viral infections affecting the upper respiratory tract can make it more difficult for doctors to correctly diagnose the situation.
In one research study, they found that 34% of patients who had a procedure to look into their lungs (a flexible bronchoscopy) but were found to not have a foreign object, still showed abnormal results on their chest X-rays. Among these patients, it was common to see thickening of the bronchial tubes. Almost half of these patients (42.5%) also showed signs of a simultaneous respiratory infection.
What to expect with Foreign Body Aspiration
A detailed study found that the death rate among children who accidentally swallowed or inhaled a foreign object was 2.5%. They also found that the location of the swallowed object in the child’s body was linked with the child’s age. In other words, the older the child, the further the object tends to travel into the body.
It was also seen that children with neurological disabilities, conditions that affect the brain and nerves, were more likely to swallow or inhale foreign objects. This condition increased the likelihood of death and the need for mechanical ventilation, a machine that helps with breathing. In fact, if the foreign object got lodged further down in the respiratory system, it could lead to more complications and a higher chance of death than if it was stuck higher up in the system. The researchers believe that this is due to the object causing a buildup of mucus which, upon later coming loose, can block the opposite lungs and cause a low oxygen level in the body.
Despite this, cases where foreign objects were lodged in the trachea, the windpipe that leads air to our lungs, were seen to have the highest requirement for using a mechanical ventilator.
Possible Complications When Diagnosed with Foreign Body Aspiration
If a foreign object is breathed into the airway and not detected promptly, it can lead to various complications. These include recurrent pneumonia, bronchiectasis where your airways become damaged and widen, lung abscesses, and atelectasis, which is a collapse or closure of lung tissue. Another known complication is bronchial stenosis, a condition where the airway becomes narrower.
In wealthy countries, the most common problem reported is tracheal lacerations, which are cuts in the trachea. However, in less affluent countries, pneumonia is the more prevalent complication. One study found that the longer a foreign object is present in the airways, the higher the risk of serious complications. It was discovered that obstructive emphysema, a type of lung disease, was the most common problem for foreign objects found more than three days after the incident.
It’s important to note that even if your x-ray looks normal and you don’t show physical symptoms, a foreign body could still be in your airway. Moreover, patients taking medicines that expand the airways and reduce inflammation may not show typical respiratory signs.
Common Complications:
- Recurrent pneumonia
- Bronchiectasis
- Lung abscesses
- Atelectasis
- Bronchial stenosis
- Tracheal lacerations (common in wealthy countries)
- Pneumonia (common in less affluent countries)
- Obstructive emphysema (common if a foreign body is detected after three days)