Monday, March 22, 2021

Inhaled Foreign Body, Pediatric Patient with a Hemoglobinopathy Case File

Posted By: Medical Group - 3/22/2021 Post Author : Medical Group Post Date : Monday, March 22, 2021 Post Time : 3/22/2021
Inhaled Foreign Body, Pediatric Patient with a Hemoglobinopathy Case File
Lydia Conlay, MD, PhD, MBA, Julia Pollock, MD, Mary Ann Vann, MD, Sheela Pai, MD, Eugene C. Toy, MD

Case 38
A 3-year-old child is brought to the emergency department accompanied by his mother for complaints of coughing and wheezing. The child was laughing at a birthday party while eating some jellybeans, when he was noted to have a “choking” episode. He immediately began to cough, and wheezes could be clearly heard. He does not have asthma, and has never experienced wheezing before. His medical history is notable for sickle cell disease.

The patient is pink, and he is conversant in full sentences. He is afebrile, his oxygen saturation is 98%, his blood pressure 100/60 mm Hg, and his heart rate 89 bpm and regular. Breath sounds are reduced and wheezes are heard on the right lower lobe.

An expiratory chest radiograph shows clear lung fields with slight hyperinflation on the right. The child is immediately scheduled for a rigid bronchoscopy for removal of the foreign body.

➤ What is the greatest hazard facing this patient and his anesthesiologist?

➤ What factors are important to ascertain with regards to this patient’s initiating event?

➤ What considerations are warranted by his sickle cell disease?


ANSWERS TO CASE 38:
Inhaled Foreign Body, Pediatric Patient with a Hemoglobinopathy
Summary: This is a 3-year-old child with a history of sickle cell disease who had a witnessed aspiration event. He is now scheduled to undergo rigid bronchoscopy for removal of the foreign body.
Greatest hazard: Complete airway obstruction. When an aspirated foreign body is lodged in the trachea, complete airway obstruction can occur at any moment if the object shifts position. When the object is firmly lodged beyond the carina, the risk of complete airway obstruction is less. It is essential not to convert a partial proximal obstruction into a complete obstruction on induction.

Important factors: Type of object and timing of event. Determining the type of object that was aspirated allows the provider to assess the risk of acute total airway obstruction, the potential difficulty of removal, and the potential airway damage from the object. Determining the timing of the aspiration event provides insight into how firmly the object is lodged in the airway and the potential for evolving airway or pulmonary complications. Patients with sickle cell disease should be kept warm, adequately hydrated, well oxygenated and ventilated, and any infections should be promptly treated.

Considerations of sickle cell disease: Patients who have suffered an acute aspiration event should be considered to have a full stomach.


ANALYSIS

Objectives
1. Understand how to preoperatively evaluate a patient who has aspirated a tracheobronchial foreign body.
2. Become familiar with the types of induction and maintenance techniques and ventilation choices that may be used in a child who has aspirated a foreign body.
3. Understand the anesthetic considerations for a patient with sickle cell disease.


Considerations
This child’s presentation is consistent with a foreign body aspiration. Not only did he have a witnessed aspiration event, but he also presents with the common symptoms of coughing and wheezing. Had his presentation been delayed, the diagnosis of the aspiration of a foreign body could have easily been mistaken for acute chest syndrome, a complication of sickle cell disease.

It is essential not to convert a partial proximal obstruction into a complete obstruction on induction. An inhalational induction has the theoretical advantage of maintaining spontaneous ventilation to prevent dislodgement of the object during induction. On the other hand, an inhalation induction poses the risk of aspiration of gastric contents in a patient with a full stomach, such as this patient who has just suffered an acute aspiration event. While spontaneous ventilation prevents the theoretical risk of pushing the foreign body further into the airway or creating a ball-valve effect with air trapping behind the foreign body, the patient will likely experience hypoventilation especially given the increased resistance of the bronchoscope. Controlled ventilation with paralysis is one way to ensure adequate oxygenation and ventilation, so important given his sickle cell disease, and to prevent coughing and bucking during rigid bronchoscopy.

In this patient, the unilateral hyperinflation seen on chest radiograph is typical of air trapping behind the foreign body. The findings on physical examination and on the chest radiograph suggest that the foreign body is in the right main stem bronchus. As this object appears to be in the bronchus, an intravenous induction is also appropriate.

Maintenance of anesthesia with either inhalational or intravenous anesthesia is effective and appropriate. However, maintaining an adequate depth of anesthesia with inhalational agents may be challenging due to a leak of anesthetic agents around the rigid bronchoscope. As with any patient with sickle cell anemia, it is important to ensure adequate oxygenation and hydration, avoid hypoventilation, and keep the patient warm.


APPROACH TO
Foreign Body Aspiration

DEFINITIONS
TRACHEOBRONCHIAL FOREIGN BODY: Any material, either organic or inorganic, that is aspirated into the tracheobronchial tree.

SICKLE CELL DISEASE: An inherited hemoglobinopathy characterized by hemoglobin S, which is an abnormal hemoglobin with a single amino acid substitution in the β-globin chain.

ACUTE CHEST SYNDROME: A complication of sickle cell disease that is characterized by a lobar infiltrate on chest radiograph along with at least one clinical feature such as chest pain, pyrexia, cough, wheezing, or tachypnea.


CLINICAL APPROACH
Tracheobronchial Foreign Body
Inhaled foreign bodies are a leading cause of accidental death among children under the age of 3. Male children account for 60% of cases, whereas female children account for 40% of cases. The majority are in children less than 3 years of age with a peak incidence of about 2 years of age.

The types of foreign bodies are subdivided into two categories: organic and inorganic. Organic material accounts for 70% to 90% of inhaled foreign bodies. Typical examples include peanuts, beans, seeds, corn, and dried fruit. Inorganic material accounts for only 10% to 30% of inhaled foreign bodies. Typical examples include toys, beads, pins, stones, and pen caps.

The diagnosis of an inhaled foreign body is suggested by the history and physical examination. The initial presentation can be acute, such as when a parent witnesses a “choking” episode or aspiration event, or delayed, when an event is neither witnessed nor noticed. Children with a delayed presentation are usually treated for asthma or for a persistent pulmonary infection that does not improve with conventional treatment. Common symptoms of inhaled foreign bodies are cough and dyspnea. Stridor and cyanosis suggest that the foreign body is in the larynx, whereas wheezing and decreased breath sounds suggest that the foreign body has migrated into the bronchus.

Since only 5% to 30% of inhaled foreign bodies are radio-opaque, a chest radiograph is not always useful in making the diagnosis. In fact, 20% to 30% of children with an inhaled foreign body have a normal chest radiograph. Nonspecific findings of atelectasis or hyperinflation due to air trapping behind the object on expiratory film are suggestive of an inhaled foreign body. Bilateral decubitus films may be useful for small children who are unable to co-operate for inspiratory and expiratory films. Hyperinflation due to air trapping in the dependant lung is suggestive of an inhaled foreign body.

For children with delayed presentations, computer tomography scans using low-dose radiation protocols may be useful in assessing for other causes of airway obstruction. As history, examination, and imaging may not clearly confirm or exclude the diagnosis in selected cases, there should be a low threshold for requesting a diagnostic bronchoscopy. While rigid bronchoscopy remains the gold standard for both diagnosing and removing tracheobronchial foreign bodies, flexible bronchoscopy is becoming more popular, although it is potentially more difficult to remove some types of objects with a flexible bronchoscope.

When a child is scheduled for a rigid bronchoscopy under general anesthesia, the preoperative assessment should focus on the location and the type of the aspirated foreign body as well as the timing of the aspiration event. If the foreign body is located in the trachea, the child is at risk for complete airway obstruction and should be taken urgently to the operating room. Foreign bodies that are located in the trachea (10%) are less common than those located in the right bronchus (50%-60%) or the left bronchus (30%-40%).

The type of foreign body is also important to ascertain since certain objects are more difficult to remove. Organic materials may swell in the airways, and the organic oils from nuts can cause localized inflammation. Sharp objects can also pierce the tracheobronchial wall, or pose the potential for damage to the tracheobronchial tree or larynx as they are removed. The presence of such objects may lengthen bronchoscopy time and may require more invasive surgical removal.

The timing of the aspiration event, whether it is an acute or delayed presentation, is important to determine. Airway edema, granulation tissue, and infection may make retrieval more difficult with delayed presentations. Also, an object that has been recently aspirated may be less stable and more likely to move to a different location in the airway. Finally, the time of the child’s last oral intake should be determined to assess the risk of aspiration. If the child is stable and there is little chance of the object being displaced more proximally, waiting for 6 to 8 hours from the last meal to allow gastric emptying may be appropriate. For urgent cases in which the child has recently eaten, the stomach contents can be suctioned through a gastric tube after induction, before bronchoscopy.

Once the child has been assessed, an anesthetic plan is formulated. The three main aspects of the anesthetic plan for the management of inhaled foreign bodies include the choice of induction, the choice of ventilation, and the choice of maintenance. The induction of anesthesia can be performed with either an inhalational or an intravenous agent. The choice of inhalational or intravenous induction is influenced if not determined by the position of the foreign body and the risk of converting a partial proximal obstruction into a complete obstruction. An inhalational induction has the theoretical advantage of maintaining spontaneous ventilation to prevent dislodgement of an unstable proximal object during induction. An intravenous induction that maintains spontaneous ventilation also accomplishes this goal. If the foreign body is wedged distally, the choice can be based on the child’s preference and whether or not he already has intravenous access.

Both spontaneous and controlled ventilation are safe and effective during removal of inhaled foreign bodies. The advantage of spontaneous ventilation is that it prevents pushing the object further into the airway. The disadvantage of spontaneous ventilation is the risk of hypoventilation due to the increased resistance of the rigid bronchoscope. The advantage of controlled ventilation is that paralysis allows for decreased coughing and bucking and improved oxygenation. The disadvantage is that a ball-valve effect might be created with positive pressure ventilation, with air trapping behind the foreign body. A prospective study demonstrates that controlled ventilation is more effective than spontaneous ventilation and that there is not an increased incidence of dislodgement of the foreign body with controlled ventilation.

The maintenance of anesthesia can be performed with either inhalational agents or with a total intravenous anesthetic. While most studies use inhalational agents for the maintenance of anesthesia, maintaining an adequate depth of anesthesia can be challenging due to hypoventilation and leaks around the rigid bronchoscope. In contrast, an intravenous technique provides a constant level of anesthesia irrespective of ventilation. Regardless of the anesthetic technique, good communication and teamwork between the anesthesiologist and the bronchoscopist are essential to minimize complications.

One of the main intra-operative complications is dropping the foreign body back into the airway. If the foreign body returns to its previous location in the tracheobronchial tree, there is usually no untoward effect. However, if it falls into the other bronchus, there is potential for complete airway obstruction due to edema and inflammation at the original site. If the object remains in the subglottic region, there is also potential for complete airway obstruction. If this occurs, and the object cannot immediately be extracted, it is best to push the object back down into a mainstem bronchus to eliminate the proximal obstruction. Dropping the foreign body has a higher correlation with operator experience than with the mode of ventilation.

Complications can occur postoperatively from the bronchoscopy, from the anesthetic, or from the foreign body itself. Bronchoscopy complications, which occur at a rate of 3% to 20% in this setting, include tracheal laceration, desaturation with or without bradycardia, laryngeal edema, and bronchospasm. Anesthetic complications, which occur at a rate of 1% to 6%, include aspiration, airway obstruction, pneumothorax, cardiac arrest, and laryngospasm. Complications from the foreign body, which occur at a rate less than 1%, may indicate bronchotomy to the remove the object or lobectomy due to bronchiectasis or fibroatelectasis.


Sickle Cell Disease
The child’s sickle cell disease adds an additional layer of complexity to the anesthetic management. Sickle cell disease is an inherited hemoglobinopathy that occurs secondary to a point mutation on the gene encoding the β-globin chain of hemoglobin A. This point mutation causes a single amino acid
substitution of valine for glutamic acid. As a result, an abnormal variant, hemoglobin S, is produced that is both less stable and less soluble than hemoglobin A. The characteristics of hemoglobin S not only cause red cell deformation and “sickling,” but also cause changes in red cell membrane structure and function, increased red cell dehydration, increased red cell adhesion, and hemolysis. Underlying mechanisms of the clinical features of sickle cell disease include oxidative damage to the red cell membrane and vascular endothelial inflammation.

The clinical features of sickle cell disease involve vascular damage in the kidneys, spleen, bone marrow, lungs, and central nervous system. These patients can develop chronic renal failure, splenic infarction, osteomyelitis, osteonecrosis, and hemorrhagic or ischemic stroke. The inflammatory response can lead to airway hyperreactivity and chronic lung disease. Patients with sickle cell disease are also at risk to develop a pneumonia-like complication known as acute chest syndrome. Acute chest syndrome is diagnosed by a new infiltrate involving a complete lung segment on chest radiograph with at least one of the following clinical features: chest pain, pyrexia, tachypnea, cough, or dyspnea.

Patients with sickle cell disease have a higher rate of perioperative morbidity and mortality as compared to the general population. Factors that are predictive of postoperative complications include the type of surgery, increased age, frequent recent complications, number of hospitalizations, chronic lung disease, and pre-existing infection. The preoperative assessment should focus on the frequency, severity, and pattern of any recent exacerbations of the child’s sickle cell disease, and the presence of any and all organ dysfunction. Exchange transfusion to dilute hemoglobin S is typically not indicated. Transfusion to a hematocrit of 30% may improve outcome, but this practice is controversial.

Intraoperative management is similar to a child without sickle cell disease in that the patient should be kept close to pre-aspiration baselines as is feasible. As in other children, hypoxia, hypoventilation leading to atelectasis, hypothermia, and aspiration of gastric contents should be avoided. Ensuring oxygenation, avoiding acidosis from hypoventilation, ensuring adequate hydration and that the patient remains warm, and treating any infection which could result from the aspiration are all indicated in this setting. Postoperative management includes standard supportive care. Sickle cell patients are at risk for developing acute chest syndrome on postoperative days 2 to 3. If this syndrome does develop, treatment includes oxygenation, bronchodilators, incentive spirometry, chest physical therapy, and possibly antibiotics.


Comprehension Questions

38.1. A 3-year-old child undergoes rigid bronchoscopy for removal of the jellybean under general anesthesia with spontaneous ventilation. As the surgeon is using graspers to manipulate the jellybean in a distal bronchus, the child coughs several times and subsequently desaturates. Which of the following would be the initial maneuver in the anesthetic management?
A. Deepen the anesthetic and control ventilation.
B. Be certain that the bronchoscope does not move back into the trachea with coughing to prevent damage to the distal airway.
C. Ask the surgeon to remove the instruments from the bronchoscope and cap it so that adequate ventilation can be provided through the bronchoscope.
D. Perform recruitment maneuvers by providing sustained positive pressure for 10 to 30 seconds to reinflate atelectatic alveoli.

38.2. A 2-year-old child underwent an uneventful general anesthetic and the jellybean removed from his right main stem bronchus. Three days later, he develops a cough and fever. A chest radiograph demonstrates a right lower lobe infiltrate. Which is the least likely diagnosis?
A. Postoperative pneumonia
B. Pulmonary edema
C. Acute chest syndrome
D. Residual tracheobronchial foreign body

38.3. A 2-year-old child is brought to her pediatrician for follow-up of persistent wheezing. She was started on albuterol inhalers 1 month ago for asthma; however, the mother states that her symptoms have not changed. She remains afebrile, hemodynamically stable, and has adequate arterial oxygenation. Which of the following is the next appropriate step in management?
A. Admit the child to the hospital for nebulizer treatments.
B. Start the child on antibiotics for presumed pneumonia.
C. Obtain inspiratory and expiratory chest radiographs.
D. Refer the child to a pulmonologist.


ANSWERS
38.1. A. This child’s hypoxia is likely due to a combination of increased oxygen consumption in children, hypoventilation with spontaneous ventilation through the rigid bronchoscope, and atelectasis induced by coughing. Appropriate management would include deepening the anesthetic to decrease coughing induced by airway manipulation and to allow for controlled ventilation. The surgeon should move the bronchoscope back into the trachea to prevent damage to the distal airways with coughing and should remove instruments from the airway to allow better ventilation through a capped bronchoscope. If oxygenation does not improve with these maneuvers, recruitment breaths can be performed.

38.2. B. Pulmonary edema, is the least likely, as it would typically present with bilateral infiltrates and not an isolated lobar infiltrate. Pyrexia, cough, and a lobar infiltrate are consistent with a diagnosis of postoperative pneumonia or with inflammation behind a retained foreign body. Since the patient definitely had a foreign body in his trachea, depending upon the type of foreign body, the possibility of retained fragments must also be considered in the diagnosis. Due to the patient’s history of sickle cell disease, he is also at risk for developing acute chest syndrome 2 to 3 days postoperatively. Pyrexia, cough, and a lobar infiltrate are also typical of acute chest syndrome.

38.3. C. While the differential for persistent wheezing is broad, this child’s history is typical for a delayed presentation of an inhaled foreign body. She is stable and is oxygenating well, so there is no need to admit her to the hospital. She is afebrile and without evidence of infection, so antibiotics are not indicated. A chest radiograph on inspiration and expiration could show a radio-opaque foreign body, atelectasis, or hyper-inflation on expiration, and is the most appropriate next step. Referring the child to a pulmonologist without further workup at this point is premature.


Clinical Pearls
➤ The anesthesiologist should establish where the object is lodged, what was aspirated, and when the aspiration occurred.
➤ The choice of induction, ventilation, and maintenance depends on an assessment of the clinical situation.
➤ Good teamwork and communication between the anesthesiologist and the bronchoscopist are essential.
➤ A basic well-conducted anesthetic is the optimal management of sickle
cell disease.

References

Aydogan LB, Tuncer U, Soylu L, Kiroglu M, Ozsahinoglu C. Rigid bronchoscopy for the suspicion of foreign body in the airway. Int J Pediatr Otorhinolaryngol. 2006;70:823-828. 

Firth PG. Anaesthesia for peculiar cells—a century of sickle cell disease. Br J Anesth. 2005;95(3):287-299. 

Firth PG, Head CA. Sickle cell disease and anesthesia. Anesthesiol. 2004;101:766-785. Soodan A, Pawar D, Subramanium R. Anesthesia for removal of inhaled foreign bodies in children. Pediatr Anesth. 2004;14:947-952. 

Tomaske M, Gerber AC, Weiss M. Anesthesia and periinterventional morbidity of rigid bronchoscopy for tracheobronchial foreign body diagnosis and removal. Pediatr Anesth. 2006;16:123-129.

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