What Is Airway Management for Pediatric Anesthesia?
Children have very different anatomical structures of the body than adults. Securing their airway is a very essential and a bit complicated task for anesthesiologists, as it requires specific tools and techniques. Also, the anesthesiologist indeed has advanced knowledge about the anatomy and physiology of the children’s bodies. Due to immature immunity, children are more susceptible to various pathological conditions and syndromes. Each one of which can be possibly associated with airway obstruction in young ones. To manage the proper air pathway, the anesthesiologist needs to customize the technique and medicine according to the anatomy and age of the children. Many of the pediatric medical tools are inspired by the tools designed for adults. However, for better adaptation, the design and size are altered accordingly.
What Is the Anatomy of the Airway?
Children have very different anatomy compared to adults, related to size, physiology, and pathology. All of these can affect the management plan of the airway in children. As many of the anatomical structures are in the developing stage, it is very difficult to manage the airway in newborns under the age of one year. As the head-to-body ratio is larger in the child due to prominent occiput, it is very difficult for an anesthesiologist to position a child. Moreover, the position of a child is important for successful airway management. While in a lying-down position when the body is flat to the surface, the possibility of airway obstruction is higher. Due to this, the anesthesiologist uses a folded towel as a shoulder roll to get the natural position of the neck and the body.
Furthermore, the anatomy of the children shows a larger occiput with a shorter neck. The structure and the size of the tongue are also larger compared to the mandibular ratio in young children. There is a presence of tonsils and adenoids in them. All of these conclusions lead to less airway space for mask ventilation, obstruction, and difficulty in surgical procedures such as laryngoscopy. In addition to these, the medications and sedatives can decrease the muscle tone of the upper airway muscle causing difficulties and obstruction.
Also, the larynx in children is located a bit higher in children, and along with the position of the mandible the other structures such as the cricoid ring and vocal cords are not in the right place. However, the location does not affect the procedure such as laryngoscopy but it can surely make the insertion of an endotracheal tube more painful and complicated.
On the other hand, the physiology of the children is very different related to oxygen consumption and carbon dioxide production. As the amount of air that moves in and out of the lungs (tidal volume) is the same as in adults. The respiratory rate in children is higher and it requires more ventilation to balance the oxygen and carbon dioxide levels in the body.
How to Assess the Airway in Children?
There are the following ways to access the airway in children, such as:
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The very first step of any successful assessment is the medical and family history. It reveals many details about any pre and postnatal complications, or any prior complications related to the situation.
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Also, it states the details about any prior trauma or injuries to the internal structures and if the patient had undergone any medical treatment or not. Also, parents or caregivers should give all the information about whether the child is or was having any respiratory infection, disability of speech and breathing or feeding.
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During the physical examination, the questions about the sleeping cycle and pattern and the history of snoring and irregular breathing during the nighttime reveals the possibility of sleep apnea.
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Moreover, the physical features such as abnormal head extension, mandibular size, and thickness of the tongue can suggest that the child might face difficulties during intubation.
What Are the Approaches to Assess the Airway in Children?
There are fundamentally three approaches that have been reintroduced for airway management, such as:
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Apneic Oxygenation: It is a very basic and important maneuver in the management of the airway. Usually, the head tilt and chin lift are the techniques used to relieve the airway obstruction during mask ventilation. Apneic oxygenation is a very old technique, where the nasal cannula is used along with a ventilation mask during induction of anesthesia. Pediatric patients are at a higher risk of atrial desaturation due to children’s lower oxygen reserving capacity and higher oxygen consumption in front of a tissue. Apneic oxygenation reduces the possibility of it. However, this technique is restricted to severely ill patients, patients with compromised lungs, and patients at the risk of aspiration.
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Extracorporeal Oxygenation: It is the technique used when the child has lost the airway completely ensuring mass resection or tracheal surgery. The oxygenation membrane and a pump maintain the complete body circulation while the heart is in the state of manual complete shutdown. Extracorporeal membrane oxygenation (ECMO) provides complete cardiac and pulmonary support in children.
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Fatal Exit (Ex Uteri Intrapartum Treatment): During this technique, the attachment of the fetus and the placenta is maintained during the cesarean delivery. Furthermore, with the attachment, the fetal airway is approached with an advanced surgical technique such as flexible fiberoptic bronchoscopy or tracheostomy. Due to ease of implementation and early diagnosis of prenatal abnormalities in children, this technique is growing day by day. Although with good results this technique shows possible complications such as placental detachment and interruption of blood flow to the fetus.
Additionally, there are three main types of devices used for the management of the airway in children, such as:
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Fatal Exit (Ex Uteri Intrapartum Treatment): The basic devices include the facial mask with or without nasal or oral cannula is the very first choice for any anesthesiologist to maintain ventilation or oxygenation in children. Secondary to that, endotracheal intubation is the next choice according to the complication and age of the children.
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Intubation Devices: There are mainly three types of devices used under this category, such as:
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Laryngoscopes: They are a myriad of intubation devices made especially for pediatric patients. Such as, laryngoscopes are available to children with the same traditional design, only with customized blade sizes. Additionally, with the advanced design, the video laryngoscope is also available in the market. With the efficient design, the video laryngoscope provides better results with minimal intubation time.
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Supraglottic Devices: From the first-generation laryngeal mask to the second-generation laryngeal mask, this supraglottic device has advanced in terms of providing easy placement, ventilation, and oxygenation with less dislodgement rate. Some of the advanced features include bite protection and easy passage for endotracheal intubation.
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Fiberoptic Bronchoscope: There are two types of fiberoptic bronchoscopes; flexible and rigid. The flexible fiberoptic bronchoscope is mainly used for diagnostic purposes, to check the airways of the lungs in some conditions. On the other hand, the rigid fiberoptic bronchoscope is used to remove obstructed foreign bodies in the airway.
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Front-Of-Neck Surgical Access (FONA): As the procedure shows a high rate of failure and possible complications associated with it, it is an unsure procedure that is mostly not recommended in very young children. In a situation where there are no available options, this can be the last choice. Usually, the procedure is done with the cricothyroid approach for children above 8 years. However, due to uncertainty and less space, the tracheal ring approach is taken for children younger than 8 years.
Conclusion:
Managing the proper airway in pediatric patients is a very difficult and important skill for the anesthesiologist. As the anatomy and physiology of children differ from adults, the techniques and tools used for them have very unique complications. However, if the anesthesiologist is aware of the anatomy and physiology of children and is specialized in the techniques and training in maintaining the airway in children, it is relatively easy for them to manipulate and execute safe pediatric airway management.
