14 – The Newborn Airway




14 The Newborn Airway


Shivani S. Patel and Narasimhan Jagannathan


Airway management poses a challenge due to the newborn’s small size, unique anatomy, and physiology. Thus, the approach to newborn airway management differs from that for older children and adults. This chapter provides an overview of a spectrum of topics important in newborn airway management, including airway anatomy and physiology, tips for adequate ventilation and intubation, one-lung ventilation techniques, management of mediastinal masses, difficult airway management, and airway management in infants undergoing mandibular distraction and tongue–lip adhesion.



Infant Airway Anatomy and Physiology


The infant respiratory system is not simply a miniaturized version of the adult system. In addition to anatomical differences (Table 14.1), significant differences in respiratory physiology exist. The newborn’s smaller airway radius creates greater resistance to air flow that in turn increases the work of breathing and offers added pressure on the lumen of the airway. Any amount of airway narrowing caused by edema, and congenital malformations, can have serious consequences on the overall work of breathing and respiratory function [1]. Combined with the infant’s higher chest wall compliance, the narrow airway also increases the incidence of airway obstruction [2]. The reduced outward recoil of the highly compliant chest wall produces low transpulmonary pressures and causes small peripheral airways to collapse during tidal breathing, predisposing to ventilation/perfusion mismatch (V/Q) [2,3] and oxygen desaturation.




Table 14.1 Unique infant airway anatomy compared to adults, and its clinical significance































Infant airway anatomy Clinical significance in airway management
Larger occiput Supine positioning on a flat surface causes neck flexion that may lead to airway obstruction; consider use of a shoulder roll
Shorter and narrow hypopharynx, higher larynx Barrier to aligning oral, laryngeal, and tracheal axes for laryngoscopy
Relative macroglossia, shorter mandible Reduced upper airway space to displace tongue into the submandibular space
Vocal cords angled more cephalad rather than at 90 degrees Vocal cords appear more anterior, potentially more traumatic tracheal tube insertion
U-shaped, long, floppy epiglottis Use of semi-straight laryngoscope blade is preferable
Cartilaginous larynx and trachea (not yet calcified) Extra compliance increases incidence of airway obstruction with positive-pressure ventilation
Funnel-shaped airway with cricoid cartilage as the functionally narrowest point; elliptical-shaped cricoid ring with larger anterior–posterior diameter Affects the airway seal of both cuffed and uncuffed tracheal tubes


Data from: [4,5,6,7,814].


The lungs of newborns are very compliant, contributing to low functional residual capacity (FRC) and dynamic airway collapse [3]. Combined with their higher oxygen consumption, this may lead to rapid oxygen desaturation during apneic periods [4,5]. Infants also have increased carbon dioxide production when compared with adults. Therefore, infants require a higher respiratory rate to achieve a relatively higher minute ventilation needed to eliminate carbon dioxide [15].



Practical Tips to Adequately Ventilate and Intubate Young Infants



Bag-Mask Ventilation


Bag-mask ventilation (BMV) is a critical component of airway management as it provides oxygenation and ventilation prior to placement of a definitive airway [16,17]. Selection of an appropriate-sized mask is essential to obtain an adequate seal. The mask should fit over the bridge of the nose, seal on the sides of the nasolabial folds, and fit between the lower lip and chin.



BMV Technique


The facemask should be held tightly to the patient’s face with the thumb and forefinger of the anesthesia providers’ left hand while the other fingers lift the mandible toward the facemask. Care should be taken to avoid excessive pressure on the submandibular soft tissue as this may cause airway obstruction. The pharyngeal space can be opened via displacement of the mandible, chin lift, jaw thrust, and atlanto-occipital joint extension, leading to greater patency of the airway [18]. While the left hand seals the mask, the right hand is used to compress the reservoir bag on the anesthesia breathing circuit to generate positive pressure. Peak inspiratory pressure should be kept below 20 cmH2O to avoid gastric insufflation of air. If a one-handed approach is insufficient, additional help may be recruited to attempt a two-handed technique in which the initial provider either maintains the same position while the secondary provider performs a jaw thrust, or uses both hands to secure the facemask while the secondary provider squeezes the reservoir bag. Additionally, use of an oral or nasal airway may help overcome difficulties in mask ventilation.



Tracheal Intubation Technique


Endotracheal intubation via direct laryngoscopy is normally chosen unless specific indications require a different approach. When intubating an infant, placing a rolled towel under the supine patient’s neck or shoulders helps improve airway patency. A laryngoscope can then be inserted to the right of the tongue to facilitate visualization. Because the infant’s epiglottis is U-shaped, long, and floppy, and less in line with the trachea, a straight laryngoscope blade is preferable to a curved blade since it directly displaces the epiglottis out of view rather than using the vallecula’s ligamentous connection with the epiglottis [6]. If the vocal cords cannot be visualized, gentle downward pressure at the level of the thyroid or cricoid cartilage may be helpful.


The tracheal tube (TT) should be introduced from the right side of the patient’s mouth with the natural curve of the tube directed anteriorly. Insertion from the right is necessary to maintain visualization of the glottic opening. The TT should be advanced so that its distal end is midway between the vocal cords and carina. It is imperative to confirm position of the TT after securing it and anytime thereafter when there is a change in position because the infant’s short trachea allows the TT to easily advance into the right mainstem bronchus [19]. Diminished breath sounds in the left lung may indicate right endobronchial intubation.


Use of a straight blade via a retromolar approach may allow better glottic visualization in infants with large tongues or small mandibles. A straight blade is inserted into the right side of the mouth, while the head is rotated to the left. This technique allows the tongue to be completely bypassed. The tip of the laryngoscope blade is then used to lift the epiglottis when it comes into view.



One-Lung Ventilation, Video Assisted Thoracoscopy


Video assisted thoracoscopic surgery (VATS) is a less invasive approach to thoracoscopic surgery, making it advantageous to use in patients. Successful VATS requires proper one-lung ventilation (OLV), with efforts to promote a quiet surgical field, avoid contamination of the normal lung, prevent hypoxemia, and minimize respiratory insults inherent in the ventilation technique [20].



Physiology of OLV


One-lung ventilation decreases functional residual capacity and tidal volume, predisposing to higher incidence of V/Q mismatch and oxygen desaturations. Hypoxic pulmonary vasoconstriction (HPV) diverts blood away from atelectatic lung tissue, normally minimizing V/Q mismatch. However, inhalational anesthetic agents in conjunction with high or low fractions of inspired oxygen reduce the HPV response [21,22].


Patients are placed in lateral decubitus position during VATS to allow for optimal access of the affected lung. However, this positioning has an unfavorable effect on respiratory physiology due to infants’ compliant lungs, underdeveloped rib cage, and low functional residual capacity [3]. When the healthy lung is ventilated in the dependent position, it will have a decrease in compliance, potentially increasing the incidence of airway closure [23]. In adults, the lateral decubitus position increases the hydrostatic pressure gradient between the dependent and nondependent lungs, favorably increasing perfusion in the healthy lung while decreasing perfusion in the diseased lung. This results in relatively even distribution of ventilation and perfusion. In infants, however, this hydrostatic pressure gradient when in the same position results in uneven distribution of ventilation and perfusion as a result of their smaller size [24]. Therefore, infants may be at risk for hypoxia during OLV in the lateral decubitus position.



OLV Techniques


The repertoire of devices suitable for OLV of the infant airway is limited. Currently, OLV in infants can be performed with a single-lumen TT or bronchial blocker, including the Fogarty® embolectomy catheter and Arndt Endobronchial Blocker® (Cook, WEB, Critical Care, Bloomington, IN, USA), because they are available in sizes suitable for the infant airway [2527]. For neonates, these options may be more limited because of sizing availabilities in the small neonate or ex-preemie. In these patients, the surgeon may find retraction of the operative lung suitable while intermittently ventilating this lung during periods of oxygen desaturations.


A single-lumen TT can be advanced to isolate the bronchi after intubation. However, intubating the left main bronchus may be challenging. Suggested techniques to facilitate blind intubation of the left bronchus include use of a stylet to curve the distal end of the tube [28] or use of a distally curved rubber bougie which can be inserted blindly into the left main bronchus, followed by insertion of the TT over the bougie [29]. It should be noted that the right upper lobe bronchus may be obstructed when intubating the right main bronchus, causing hypoxia. Also, a single-lumen TT may not adequately seal the bronchus, risking contamination of the healthy lung and preventing collapse of the pathologic lung [25,30].


The bronchial blocker (BB) may also be used to achieve OLV in infants. An advantage of a BB versus a TT in sealing the bronchus is that the former provides a tighter seal. The Fogarty embolectomy catheter and Arndt Endobronchial Blocker have been successfully used for lung isolation in infants [31]. Proper placement of the Fogarty catheter is facilitated by bending the tip of its stylet toward the bronchus on the operative side. Positioning can be directed and confirmed with fiberoptic bronchoscopy (FOB) or fluoroscopy. Infants may require parallel insertion of the Fogarty catheter alongside the TT [32]. One such method for parallel insertion involves intubating the bronchus on the operative side with an TT, advancing a guide wire through the TT and into the bronchus, then removing the TT, and finally advancing the blocker over the guidewire into the bronchus [32]. It should be noted that since embolectomy catheters have low compliance and high pressure properties, the balloon should be inflated with incremental volumes of air until the airway is sealed. This will prevent over-distention, which can damage or rupture the airway [27,33].


More recently, the Arndt Endobronchial Blocker has been successfully used for OLV in small infants [31,34]. An advantage of the Endobronchial Blocker is that a central channel is present to allow for complete lung deflation. This feature is not present in the Fogarty catheter, so complete lung deflation may not be possible when using this device. The Arndt Endobronchial Blocker has a flexible wire loop and a three-part swivel adaptor. This adaptor allows for insertion of an FOB and balloon-tipped BB in two ports, and use of the third port as a ventilation circuit. The balloon is high-volume, low-pressure, and comes in two shapes to allow for optimal fit into the two mainstem bronchi: spherical for the right main stem bronchus and elliptical for the left main stem bronchus. Additionally, it is available in 1.0 cm length, corresponding to the length of the right main stem bronchus in the average child of two years of age. This enables it to fit entirely within the shorter right main stem bronchus, preventing obstruction of the upper lobe bronchus [35]. While coaxial insertion of the blocker and use of FOB can be accommodated in the relatively larger airway of older children, infants require a 5 French size Arndt Endobronchial Blocker and parallel insertion of the blocker due to the small diameter of their airway [27,36]. Additionally, passage of an FOB in an indwelling TT may be restricted in infants, in which case fluoroscopy may be used to guide insertion [36].



Pre- and Intraoperative Management of Mediastinal Masses


Mediastinal masses encompass a diverse group of benign and malignant tumors that may be classified based on their location in the mediastinum [37]. These tumors have respiratory and hemodynamic consequences. In general, tumors of the anterior mediastinum comprise 46 percent of mediastinal masses in infants and children [3841]. These tumors cause the most severe complications relating to compression of the airway and vasculature. It should be noted, however, that pediatric patients have an increased incidence of neurogenic tumors compared to adults [3841], and these masses complicate airway management [42]. Although mediastinal tumors are rare in neonates, case reports have described mediastinal teratomas and cystic hygromas as important causes of respiratory distress in this population [43,44]. Cystic hygromas may be localized to the mediastinum or arise in the neck and extend down into the mediastinum, causing airway obstruction [43,45].


Tumors on the extreme end of the disease spectrum pose the greatest difficulty to management in the perioperative period, leading to severe cardiorespiratory complications and even death in children [46,47]. These problems can be exacerbated by general anesthesia [48,49]. As management of mediastinal masses in pediatric patients typically involves surgical biopsy or resection under general anesthesia with tracheal intubation, an understanding of risk factors for complications under anesthesia, preoperative testing, and intraoperative techniques to manage these tumors is necessary.


Mediastinal masses may lead to several forms of intrathoracic compromise, including one or a combination of compression of the tracheobronchial tree, compression of the pulmonary artery and heart, and superior vena cava syndrome [50,51]. Pulmonary symptoms such as dyspnea at rest, postural dyspnea, and stridor are strong risk factors for intraoperative airway complications [50,52], and symptoms such as syncope, arrhythmias, head and neck edema, and cyanosis predict cardiovascular complications in pediatric patients [50,52]. The absence of such symptoms, though, does not exclude the possibility of airway or circulatory collapse under anesthesia [53,54]. Moreover, symptoms that are described may be worse in the postoperative period due to the effects to general anesthesia [47].


Careful preoperative testing can help gauge the severity of a patient’s respiratory compromise and estimate the risk of adverse events under anesthesia. Computed tomography (CT) scanning is routinely used and provides the greatest amount of information concerning size of the mass, its location, and incursion on surrounding structures. Pulmonary function testing may reveal limited expiratory flow predictive of airway collapse under anesthesia [46], while echocardiography is useful in characterizing masses that may not compress the airway or cardiovascular systems but which will cause airway obstruction and cardiovascular collapse after induction of general anesthesia [55]. Additional tests may be used to enhance anesthetic management for specific tumors. A thyroid scan may be helpful when a thyroid mass is suspected, but should be performed first if iodinated contrast is used in the CT scan. Magnetic resonance imaging (MRI) may elucidate information on a neurogenic tumor, and positron emission tomography can be used for follow-up of germ cell tumors after treatment.


Intraoperatively, the anesthesiologist may employ a variety of techniques to manage mediastinal masses. Inhalational induction with maintenance of spontaneous respiration is recommended for infants with anterior mediastinal masses [56]. As functional residual capacity may be reduced under anesthesia, continuous positive airway pressure may also be helpful [46]. Elevation of the head of the bed mitigates undesirable effects of the supine position such as reduction of thoracic volume due to cephalad displacement of the diaphragm [47], and airway patency can also be maintained by placing the patient in partial or full lateral decubitus position [46].


When performing tracheal intubation, the clinician should consider placing an armored endotracheal tube without the assistance of neuromuscular blocking agents, as their administration may increase the risk of severe airway compression [57,58]. Alternatively, a supraglottic airway may provide sufficient ventilation [59]. If tracheal or bronchial collapse occurs, rigid bronchoscopy may be a useful option [46]. In general, when a compressed or distorted airway is a concern during anesthesia, a helium–oxygen gas mixture may be used as it allows for laminar air flow and minimizes resistance to gas flow in the airways [59,60].


If patients are at high risk of intraoperative airway obstruction, presurgical treatment of the mediastinal mass with steroids, chemotherapy, and/or radiotherapy may be helpful [52]. However, this approach may lessen the accuracy of diagnoses drawn from biopsies. Therefore, many clinicians recommend that, except in extreme circumstances, tissue diagnoses should be obtained prior to treatment, even if general anesthesia is required [61]. In patients with severe airway narrowing and pulmonary artery involvement, cardiopulmonary bypass may facilitate intraoperative gas exchange.



Management of the Recognized and Unrecognized Difficult Airway


The difficult airway is typically defined by the inability to provide adequate mask ventilation and/or difficulty with tracheal intubation when using a traditional laryngoscope. The incidence of difficult airways is common in infants, particularly under the age of one year [62]. Therefore, it is prudent to have preplanned protocols in place to approach both the recognized and unrecognized difficult airway situations.



The Anticipated Difficult Airway


The anticipated difficult airway scenario commonly arises in patients with craniofacial syndromes. Thus, it is imperative to perform a thorough preoperative assessment to pinpoint the area of obstruction and help gauge the success of various strategies to achieve adequate oxygenation. A useful approach to predict areas of obstruction is to group syndromes according to the associated functional abnormality [63]. Table 14.2 lists several encountered syndromes with abnormal airways grouped as such, and suggests airway management strategies.




Table 14.2 Craniofacial syndromes grouped by functional abnormality

















































Functional abnormality Craniofacial syndrome Physical features contributing to difficult airway Possible airway management strategies
Subglottic abnormality Crouzon, Apert, Pfeiffer Syndromes [6567] Facial/maxillary hypoplasia; prematurely fused cranial sutures Oro- or nasopharyngeal airway; SGA; CPAP; consider indirect laryngoscopy in patients who have undergone previous corrective surgery or who have a rigid external distraction device
Pierre Robin sequence [68] Mandibular hypoplasia; relative macroglossia/glossoptosis; ± cleft palate Prone positioning; video laryngoscopy; lightwand, paraglossal approach with gum-elastic bougie; SGA to overcome upper airway obstruction; SGA-assisted flexible fiberoptic intubation
Treacher Collins syndrome [69,70] Mandibular, maxillary, and zygomatic hypoplasia; small mouth; temporomandibular joint abnormalities Video laryngoscopy; SGA to overcome upper airway obstruction; SGA-assisted fiberoptic intubation
Hemifacial/bilateral facial microsomia/ Goldenhar’s syndrome [7073] Mandibular, maxillary, and malar hypoplasia; facial asymmetry; cleft-like extension on affected sides(s) of the face

Goldenhar’s syndrome: cervical spine defects
SGA to overcome upper airway obstruction; SGA-assisted fiberoptic intubation, videolaryngoscopy; lightwand
Abnormality of the entire airway, including the glottis Mucopolysacchariodoses [68,7477] Mucopolysaccharide deposits causing macroglossia, thickened oropharyngeal, laryngeal, and nasal mucosae. Restricted temporomandibular joint mobility, narrow trachea Avoidance of neuromuscular blocking agents until airway is secured; SGA; SGA-assisted flexible fiberoptic intubation; elective tracheostomy; surgical airway backup
Subglottic abnormality Down syndrome [68, 7880] Subglottic stenosis, macroglossia, hypotonia, atlantoaxial instability Straight blade; video laryngoscopy; use of smaller diameter TTs than calculated; neutral neck position
Larsen syndrome [81,82] Subglottic stenosis; laryngotracheomalacia; short neck; cephalad larynx; cervical spine instability Use of smaller diameter TTs than calculated; neutral neck position
Fraser syndrome Subglottic stenosis, webbing, or atresia (may make intubation impossible) Use of smaller diameter TTs than calculated; SGA as primary means of ventilation


SGA, Supraglottic airway; CPAP, continuous positive airway pressure; TT, tracheal tube.


Source: [63,64].

Management of tracheal intubation poses a problem in infants and children as it is often impractical to perform awake intubations due to lack of cooperation [7]. Therefore, the clinician must consider whether or not intubation is safe to perform after induction of general anesthesia. Additionally, the feasibility of direct laryngoscopy is important to consider so that alternative devices can be readily available. Generally, direct laryngoscopy is difficult in these populations, particularly in patients with limited mouth opening [83]. If intubation is deemed unsafe to perform, alternative methods of achieving adequate oxygenation such as mask ventilation or use of a supraglottic airway (SGA) should be considered. It should be noted, however, that functional airway obstructions increase difficulty of mask ventilation [84] due to poor mask seal or supraglottic obstruction [83]. Supraglottic airways can often overcome these difficulties [83]. However, awake intubation may be the safest option in the case of difficult mask ventilation, severe upper airway obstruction, or risk of regurgitation and aspiration of gastric contents. It has been shown that placement of SGAs in the awake state may be useful in infants with craniofacial syndromes that exhibit upper airway obstructions [85,86].


Neuromuscular blocking drugs (NMBDs) help support tracheal intubation and also mitigate the risk of adverse events such as reflex airway activation [84]. They are not appropriate for every intubation scenario [65,87], and their use should be guided by the underlying airway pathology, expected ability to perform mask ventilation, and whether or not native muscle tone is needed to keep the airway patent (i.e., anterior mediastinal mass) [83]. Additionally, evidence is unclear on the use of NMBDs versus maintenance of spontaneous ventilation in managing the difficult pediatric airway [83]. In typical clinical practice, however, the difficult pediatric airway is managed after anesthetic induction and with maintenance of spontaneous ventilation.



Devices to Aid in Difficult Airway Management


The difficult airway can be successfully managed with the aid of a number of available devices. These devices include the flexible fiberoptic bronchoscope, indirect laryngoscopes, and SGAs.


The flexible fiberoptic bronchoscope is the “gold standard” in navigating a difficult tracheal intubation [7] and is available in an ultra-thin 2.2 mm external diameter size that is suitable for the newborn airway [87]. Video and optical layngoscopes are a more recently available option to guide tracheal intubation when direct laryngoscopy is not feasible. A wide variety of designs are available, and all combine a blade with a video camera or fiberoptic bundle to facilitate laryngeal visualization for oral and/or nasotracheal intubation. Also, if mouth opening permits, an SGA may be used as a primary [6465] or temporary means to secure the airway. These devices do not require optimal anatomic positioning to achieve adequate ventilation [88]. However, when used as a means to achieve tracheal intubation, the assistance of visualization techniques as opposed to blind intubation may prove more successful [89].


Table 14.3 highlights the strengths and limitations of using these devices to manage the difficult airway.




Table 14.3 Devices to aid in difficult airway management of the infant and neonate
























Device Strengths Limitations
Flexible fiberoptic bronchoscope [7,68,83,87, 9094] •  Allows for tracheal intubation via oral or nasal route or through an SGA

•  Useful in patients with limited mouth opening

•  Permits lower airway examination

•  Assists in positioning bronchial blockers

•  Most sizes have a suction port to remove secretions in the airway

•  Working channel allows for delivery of local anesthesia
•  Difficult to manipulate, particularly the ultra-thin bronchoscope (<3.0 mm OD)

•  Ultra-thin bronchoscope lacks a suction port

•  Image may be obscured by blood and secretions in the airway

•  Steep learning curve, regular practice needed to maintain proficiency

•  Higher cost, delicate, and costly to repair

•  Time intensive to setup and clean up
Indirect laryngoscope [68,95104]

GlideScopeTM

Stortz DCITM

Truview PCDTM

AirtraqTM

Pentax Airway Scope

(AWS)TM

Optical stylets: Bonfils

Intubation Stylet

and Shikani Optical

Stylet
•  Less head and neck movement required vs. direct laryngoscopy

•  Improved glottic views compared with direct laryngoscopy

•  Laryngeal inlet may be visualized without alignment of the oral, pharyngeal, and laryngeal axis

•  LEDs of the GlideScope and Pentax AWS prevent fogging by providing heat

•  Most devices have a quick learning curve
•  Airway visualization may be obscured due to blood and secretions

•  Difficult to manipulate TT through the glottis

•  Risk of failure with altered neck anatomy associated with a mass, radiation changes, or a surgical scar

•  Evidence for the efficacy of some devices in managing the difficult infant airway is lacking
Supraglottic airway devices [7,64, 68,89, 105, 106, 107112]

Air-QTM

Classic LMATM

Supreme LMATM

Proseal LMATM

i-gelTM
•  Useful alternative when mask ventilation is difficult

•  Functions as a conduit for tracheal intubation

•  Adequate and efficient ventilation: does not rely on optimal device positioning even in the difficult airway

•  Devices with gastric drain tubes are available to help protect against regurgitation of gastric contents

•  air-Q can accommodate cuffed TTs
•  Two-step process when used as a conduit for intubation

•  Classic LMA may produce delayed airway obstruction in neonates

•  Narrow lumen of LMA Supreme restricts TT insertion and fiberoptic intubation

•  Narrower lumen of LMA ProSeal restricts TT insertion


LMA, laryngeal mask airway; TT, tracheal tube: LED, light-emitting diode.



The Unanticipated Difficult Airway


The unanticipated difficult airway often becomes known after anesthetic induction. A preplanned structured approach facilitates successful navigation of the situation, though management should ultimately be guided by the patient’s condition and available resources.


Achieving adequate mask ventilation alone may be difficult. In this scenario, consider recruiting help and attempting a two-handed bag-mask technique. Alternatively, the SGA is a useful rescue device when mask ventilation or intubation are unsuccessful [113].


Difficult intubation may also be an issue. If direct laryngoscopy proves impractical, methods of indirect visualization are useful in increasing the frequency of successful intubation and successful first attempt intubation [113]. Additionally, an SGA may be used as a conduit for tracheal intubation [113]. However, care should be taken to avoid an excessive number of intubation attempts as even gentle instruments may cause iatrogenic injury to the fragile infant airway [83]. When these methods fail to adequately ventilate and oxygenate the patient, a surgical airway may be a necessary. Figure 14.1 is a proposed algorithm for management of the unanticipated difficult airway in the child.





Figure 14.1 A proposed algorithm for management of the unanticipated difficult airway in the child.


Source: adapted from Difficult Airway Society. Paediatric Difficult Airway Guidelines for: Difficult Mask Ventilation; Unanticipated Difficult Intubation; and Cannot Intubate and Cannot Ventilate. CPAP, continuous positive airway pressure; FOI, fiberoptic intubation; NMBD, neuromuscular blocking drug; SGA, supraglottic airway device; TT, tracheal tube.


Cannot Intubate, Cannot Ventilate


The “cannot intubate, cannot ventilate” situation can be a very stressful scenario to encounter, particularly because there are limited rescue options for infants. Both surgical tracheostomy and percutaneous cricothyroid puncture are invasive and high-risk [83]. Ideally, the assistance of an otolaryngologist should be solicited for creating a surgical airway [83]. However, if help is not close at hand, the more efficient, but risky, method for invasive tracheal access is needle cricothyrotomy [83,114]. This procedure has limited efficacy in infants [83,115]. This is due in part to their proportionately smaller cricothyroid membrane, which restricts the size of the transtracheal catheter that may be used for oxygenation [83,116]. There is also a high incidence of complications associated with this procedure, such as posterior tracheal wall puncture, and esophageal puncture [114,117].


If needle cricothyrotomy is necessary, procedure-specific equipment such as the Ventilation-Catheter (VBM, Medizintechnik GmBH, Sula and Neckar, Germany) may be used with either bag or jet ventilation [114]. In the resource-limited setting, a makeshift device composed of a large-bore intravenous catheter, a syringe, and 3.0 mm internal diameter tracheal tube will suffice with bag ventilation [114]. The Enk Oxygen Flow ModulatorTM (Cook Medical, Bloomington, IN, USA) is a lower-pressure jet ventilation system that can provide adequate oxygenation utilizing standard wall oxygen, with a lower risk of barotrauma [114]. However, current knowledge suggests that jet ventilation through transtracheal catheters is associated with serious complications and barotrauma [19,118], and further evidence is needed to elucidate whether or not these devices minimize pressure-related complications [119].



Management for Tongue–Lip Adhesion and Mandibular Distraction Osteogenesis


Mandibular distraction osteogenesis (MDO) and tongue–lip adhesion are common surgical interventions to relieve upper airway obstruction in infants and neonates with craniofacial deformities. A difficult airway should be anticipated in these patients.


Nasal intubation is preferred for both MDO and tongue–lip adhesion as it minimizes disturbance to the surgical field. While awake fiberoptic intubation is the most conservative approach to achieve ventilation in these patients, lack of patient cooperation may make it unfeasible. A more practical option involves mask induction followed by asleep fiberoptic intubation. Use of a nasopharyngeal airway during nasal fiberoptic intubation in small children with difficult airways may help overcome obstruction and allow the clinician to provide CPAP, analogous to using an SGA for fiberoptic intubation [120]. If an ultra-thin flexible fiberoptic bronchoscope is available, a TT may be advanced over the scope for successful intubation of the infant or neonate [121]. However, if this approach is unsuccessful, or only a larger diameter scope is available, a guidewire may be used to facilitate intubation [122]. The guidewire is threaded through the working channel of a larger diameter bronchoscope, the bronchoscope is withdrawn and an airway exchange catheter can be placed over the guidewire to allow for railroading of the TT over it.


Retrograde nasotracheal intubation is also an alternative to achieve adequate ventilation in neonates and infants [123,124]. The airway is first secured orally, typically via SGA-assisted tracheal intubation. After the SGA is removed, a smaller TT is placed into the nose and the end is exited out of the mouth. It is then telescoped into the larger TT and secured with a suture. Both TTs are pulled retrograde out of the nose and separated, leaving the larger TT trans-nasal.


It should be noted that glossoptosis may make intubation difficult in patients with Pierre Robin sequence. In this case, the tongue can be held with Magill forceps during intubation [122], or nasotracheal intubation may be performed in the prone position. Jaw thrust is another helpful maneuver to increase airway patency.




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Oct 11, 2020 | Posted by in ANESTHESIA | Comments Off on 14 – The Newborn Airway
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