This chapter is designed to cover management of the pediatric airway under four subheadings:
- Differences between pediatric and adult airway
- Armamentarium of pediatric airway devices and associated equipment
- Special airway techniques in children
- Management of the difficult airway.
Normal Pediatric Airway
The area of greatest anatomic difference between an infant and an adult is in the airway (Fig. 1.1).
Knowledge of these anatomical differences is essential for every practitioner to understand pediatric airway management (Table 1.1).
The salient physiological differences are mentioned in Table 1.2.
Pediatric Airway Devices and Associated Equipment
There are many airway devices available to manage the pediatric airway. However, choosing the right airway device is a critical decision which depends on the experience and familiarity with the device.
These devices can be grouped into three main categories:
- Face masks and airways
- Tracheal tube and its alternatives
- Conventional rigid laryngoscope and its alternatives.
The face mask is an essential adjunct for airway management in almost all situations. It is frequently used prior to laryngeal mask airway (LMA) or endotracheal tube (ETT) insertion and also for non-invasive positive pressure ventilation for treatment of respiratory failure. These masks are made up of non-conductive black rubber (neoprene), clear plastic or elastomeric material. Scented disposable PVC cushion face masks are commonly used in contemporary pediatric practice (Fig. 1.3), but the anatomical black rubber face mask (Connell mask) is preferred in larger patients. Circular pediatric masks are available in silicone or black rubber versions (Fig. 1.4).
The face mask has a body, a seal and a connector. A transparent body is more acceptable to the patient and also allows observation of vomitus, secretions, blood, lip color and exhaled moisture.
The seal is either an air-filled cushion or a flap which conforms to the contour of the face. The connector part consists of a thickened fitting of ID 22 mm. A ring with hooks around the connector allows fixation with a harness or strap. The Rendell-Baker-Soucek (RBS) mask is specially designed for neonates and has a triangular body with minimal dead space (one quarter of the anatomical face mask) (Fig. 1.5). It can also be used to achieve controlled or assisted ventilation over a tracheostomy stoma with its nasal end pointing caudally.
The endoscopic mask has a port for insertion of a fiberscope through nose or mouth while allowing simultaneous mask ventilation. The available sizes are usually for children more than four years of age (Fig. 1.6).
Selection of a face mask of appropriate size and shape ensures a proper mask-fit for optimal ventilation with the least increase in dead space (Table 1.3). The commonly used methods of holding a mask to maintain a patent airway with a tight seal are (Figs 1.7A to C):
(i) One-hand method, (ii) Two-hand method, (iii) Claw-hand method.
- One-hand method (E-C clamp technique): The thumb and index finger of the left hand are placed on the mask body to form a ‘C’ to hold the mask on the patients’ face while the remaining three fingers are placed on the inferior surface of the mandible to form an ‘E’ to lift the jaw into the mask. Care should be taken to avoid pressure on the eyes and compression of the submental soft tissues, since in young children the tongue can be pushed up to cause airway obstruction.
- Two-hand method: This method is used when the one-hand method is ineffective. A second person is required if manual assisted or controlled respiration is needed.
- Claw-hand method: This method is useful in short duration ophthalmic procedures where the anesthesiologist stands on the side facing the child. The face mask is applied in such a manner that the ring finger and middle finger go under the angle of the jaw on the opposite side and the thumb and index finger encircle the body of the mask to achieve a good seal.
Figs 1.7A to C: Mask holding methods: (A) One-hand method; (B) Two-hand method; (C) Claw-hand method
The palmar surface of the anesthesiologist's hand faces upwards unlike in the previous methods where it faces downwards.
- Lower incidence of sore-throat
- Requires less anesthetic depth
- Cost-efficient method to manage the airway for short cases.
- User fatigue
- Higher fresh gas flow required
- Not useful in remote anesthesia (i.e. MRI/CT scan)
- More episodes of oxygen desaturation
- PaCO2-EtCO2 gradient higher particularly with small tidal volume because of large dead space ventilation
- May require more frequent intraoperative airway manipulations
- Work of breathing increases during spontaneous breathing.
- Gastric inflation during controlled ventilation
- Skin allergy to the material or residue from chemical or gas sterilization
- Eye injury due to ill-fitting mask and undue pressure applied
- Nerve injury due to pressure from mask or strap, stretching from extreme forward jaw displacement or unstable cervical spine.
Airways lift the tongue and epiglottis away from the posterior pharyngeal wall thus preventing obstruction of the space above the larynx. Airways always require a face mask as a ventilatory device and decrease work of breathing during spontaneous respiration. The airway may be inserted via the oral or nasal route. The nasopharyngeal airway is used in a pediatric patient with gag reflex while an oropharyngeal airway is for patients without gag reflex. Sizing of the airway is in the same way as for an adult. Measurement landmarks are from the corner of the mouth or nose to the tip of the ear lobule.
- Airway obstruction by the tongue or epiglottis due to incorrect size or improper insertion
- Trauma to nose, lip, tongue, teeth and pharynx
- Tissue edema, ulceration and necrosis of nose or tongue when airway is in situ for an extended period
- Coughing and laryngospasm if airway is introduced during inadequate depth of anesthesia.
These are made of PVC or elastomeric material. Each airway has a flange at the buccal end to prevent over-insertion. The bite portion is straight, fits between the teeth or gums and is reinforced to prevent occlusion by biting. The curved portion extends backwards to correspond to the shape of the tongue and palate. Oral airway insertion does not cause movement of cervical spine. The oral airway does not need to be inverted when inserted into the mouth of an infant or small child. It should never be inserted in case of epiglottitis as total airway obstruction may be precipitated. The most popular oral airway is the Guedel airway which has its bite-portion color-coded according to size (Fig. 1.8) (Table 1.4). The dual channel design of Berman oral airway allows access of a suction catheter and a color coded version is also available for easy identification (Fig. 1.10).
- Maintains an open airway
- Facilitates oropharyngeal suctioning
- Protects tongue or orotracheal tube from being bitten
- Provides a pathway for inserting device into pharynx or esophagus.
Nasopharyngeal airways are made of rubber or plastic and are available in various sizes (Figs 1.11A and B). The anatomic constraints of the nasal passages limit the scope for various designs of nasal airways. Most consist of a flange and a curved cylindrical tube. The flange, sometimes aided with a safety-pin, prevents it from slipping deep into the nose.
The tube is curved to follow the anatomic shape of the nasal floor and nasopharynx. Most nasal airways are uncuffed and use one nostril, but some are cuffed. A binasal airway consists of two nasal airways joined together by an adapter for attachment to a breathing system or CPAP machine (Fig. 1.12).
Nasal airway should be lubricated thoroughly along its entire length. A vasoconstrictor may be applied to the nostril before insertion of airway to reduce trauma. Insert the airway gently without resistance, in a perpendicular direction with the curve oriented towards the mouth. Too deep an insertion may stimulate the laryngeal reflex and too short an insertion may not relieve airway obstruction. Ideally, when fully inserted, the pharyngeal end should be below the base of the tongue, but above the epiglottis (Table 1.5). The ideal size is 0.5-1 mm smaller than the appropriate orotracheal tube. Nasopharyngeal airway is available in sizes 2 to 8.5 mm which indicate the internal diameter in millimeters (Fig. 1.13).
- Situations where access to the mouth is limited
Table 1.5 Size of nasal airways with adjustable flange (Fig. 1.14)Size/ID (mm)OD (mm)Length (mm)24952.54.735.33.564.56.712557.31705.5868.7
- Useful back-up when orally inserted airway fails
- Awake, semi-comatose or lightly anesthetized patients—better tolerated and less easy to dislodge
- Cuffed nasal airway for ventilation
- Guidance of fiberoptic instruments, suction catheters, and nasogastric tube into the laryngopharynx.
- Nasal pathology
- Fracture base of the skull
- Bleeding disorders
- Large adenoids or tonsils.
Airway devices can be further divided into:
- Supraglottic devices
- Infraglottic devices.
These cuffed devices are inserted blindly via the oral route, to secure airway in case of elective or emergency situations. The tip of the device sits in the hypopharynx and its cuff or base forms a seal incorporating the supraglottic area. These devices can be used for spontaneous as well as positive pressure ventilation, but do not provide adequate protection against aspiration. They can be further grouped as:
- Laryngeal mask airway (LMA)
- Non-LMA supraglottic devices
- Cuffed oropharyngeal airway
- Laryngeal tube and laryngeal tube suction device
- Cobra perilaryngeal airway
Laryngeal Mask Airway
The LMA is the most frequently used and tested supraglottic airway device. It consists of a curved shaft and an elliptical spoon shaped cup surrounded by an inflatable cuff with an inflation tube along with a self-sealing pilot balloon (Fig. 1.15) (Table 1.6).
The LMA family now includes a variety of LMAs and the advanced use of special purpose LMAs requires an impeccable technique and good communication with the operating surgeon (Table 1.7).
Too large a size is difficult to place whereas too small a size predisposes to gas leak during positive pressure ventilation.
One size smaller and one size larger than the chosen size should always be immediately available. The inflating syringe should be dry and contain only air. Method of insertion can be the classic insertion with deflated cuff or partially deflated with the lateral insertion technique or with mask opening facing the palate till base of tongue is bypassed and then rotated 180° into the final position. Since there is no statistical difference between the different methods of LMA insertion, it is better to change to another when one method is not working.
- Easy insertion
- Reliable performance
- Less invasive than intubation
- Decreased incidence of trauma, sore throat
- Facilitates smooth emergence
- Cost-effective as requires lesser anesthetic depth.
- Epiglottic downfolding
- Inadequate protection against aspiration.
- Provides airway under anesthesia during elective operative procedures, for spontaneous or controlled ventilation
- In procedures outside the operating room such as GI endoscopy, flexible bronchoscopy, interventional radiology, radiation therapy
- As a conduit for ETT in the management of the difficult airway
- Provides airway during resuscitation (ASA guidelines)
- Conduit for drug administration (i.e. surfactant to neonate with respiratory distress syndrome)
- Useful alternative for airway control in children with an upper respiratory infection.
Cuffed Oropharyngeal Airway (COPA)
This supraglottic device is a modified Guedel oral airway with a cuff at its distal end, which creates a seal between the patient's upper airway and the anesthesia delivery system (Fig. 1.29). When the cuff is inflated, it displaces the base of the tongue anteriorly and passively elevates the epiglottis away from the posterior pharyngeal wall. The proximal end has a standard 15 mm connector for connecting the device to the anesthesia circuit, an integrated bite-block (tooth-lip guard) and two posts for attaching the elastic fixation strap.
Figs 1.18A to E: (A) LMA ProSeal (sizes 1, 1.5, 2, 2.5); (B) PLMA with cuff deflator; (C) PLMA with deflated cuff; (D) PLMA with introducer; (E) PLMA in situ with cuff pressure measurement
The number of sizes available refers to the distance in centimeters between the tooth-lip guard and the distal tip. The bite block is color coded for size. The smallest size available is suitable for bigger children only (Table 1.8).
Cuffed oropharyngeal airway (COPA) size can be determined by measuring the distal tip of the device at the angle of the jaw with the COPA perpendicular to the patient's head (as for oral airway). Selecting the right size is the most important step in using the COPA. The technique of insertion is the same as that for an oral airway. After insertion the COPA should be strapped with colored bite block between the teeth in the midline. Then the jaw thrust/chin lift is done and cuff is inflated with the appropriate volume of air.
Indication: Obese pediatric patients with small mouth undergoing general anesthesia with spontaneous ventilation for minor surgery or any painful procedure.
- Easy insertion even in inexperienced hands
- Less anesthetic depth required when compared to LMA
- Allows hands free anesthesia.
- Frequent airway manipulations may be necessary intraoperatively
- Not suitable for controlled ventilation as the airway seal pressure is low.
Laryngeal Tube (LT)
This newly developed supraglottic device consists of a relatively wide and curved single lumen tube with two anterior facing, oval-shaped ventilation outlets in between its two low pressure high volume cuffs'a large proximal oropharyngeal cuff near the middle of the tube and a small distal esophageal cuff near the blind distal tip.
It is available in both reusable (silicone) and disposable (PVC) versions. It is available in six sizes with color coded connector according to size. One inflation tube inflates both light blue cuffs simultaneously. The approximate inflation volume is indicated on syringe with color coding (Table 1.9).
In neutral or sniffing position, the fully deflated device is inserted in midline and slid along the palate into the hypopharynx until resistance is felt. The three black marks on the shaft should align with the upper incisors (thicker middle line for orientation, thinner lines for eventual repositioning). The cuffs are inflated to a pressure of 60 cm H2O. The inflated proximal cuff stabilizes the tube and blocks oropharynx and nasopharynx.
- Easy insertion
- Useful for both spontaneous and controlled ventilation
- Ventilatory holes act as a guide for airway exchange catheter placement or fiberscope and also allow suction.
- Risk of gastric inflation is low as distal cuff blocks esophageal inlet, so protects against aspiration
- Higher ventilation pressure can be used when required
- Especially useful for resuscitation in the difficult airway scenario
- Low laryngopharyngeal morbidity.
- PLMA proves superior to LT
- In manual in-line neck stabilization, ILMA proves superior to LT.
Laryngeal Tube Suction (LTS) Device
This device is identical to LT in terms of its size and method of insertion. It is available in both reusable and disposable version. It has an additional (esophageal) lumen posterior to the respiratory lumen that ends just distal to the esophageal cuff for suction and gastric tube placement. LTS has been recommended as the first line device to secure the airway in a difficult airway. However, as with all supraglottic devices, familiarity and clinical experience with the device and its insertion technique is essential for safe and successful use, especially in an emergency.
Cobra Perilaryngeal Airway (Cobra PLA)
This disposable supraglottic device is a single lumen breathing tube with a wide, tapered distal end (cobra head design). It has a low pressure, high volume, oval cuff attached just proximal to the wide part.
It is termed perilaryngeal because when positioned in hypopharynx, the distal end abuts the aryepiglottic folds and directly sits on the laryngeal inlet. The distal ventilatory end has a unique design such that the series of slots prevent the ventilatory hole from being obstructed by the epiglottis and soft tissue (Figs 1.31A and B).
Inflation of cuff to a pressure less than 25 cm H2O seals off the distal end from the upper airway and allows positive pressure ventilation. The device is available in eight sizes, out of which five sizes are for pediatric age group (Table 1.10).
With the patient in a sniffing position, the deflated and lubricated device is inserted in midline back into the mouth (not towards the hard palate) until resistance is felt. The cuff is inflated with enough air to obtain an adequate seal.
- Useful alternative in “Cannot ventilate cannot intubate” (CVCI) situation
- Easy insertion, less sore throat
- Large lumen as a conduit for ETT or fiberscope
- Short breathing tube allows ETT to pass below vocal cords without removing it.
- No protection against aspiration
- Cuff leak
- Possible airway obstruction.
Esophageal Tracheal Combitube (ETC)
It is a disposable double-lumen tube that combines the features of a conventional ETT and that of an esophageal obturator airway. It has a large proximal latex oropharyngeal balloon and a distal esophageal low-pressure cuff with eight ventilatory holes in between.
Ventilation is possible with either tracheal or esophageal intubation(Fig. 1.32). It can be inserted blindly, quickly and with a relatively low level of skill. It enters the esophagus in 99% of insertions. It reduces the likelihood of aspiration.
- Elective or emergent situations, both in and out of hospital environment
- Situations where neck movement is contraindicated
- Limited access to airway
- CVCI situation
- Massive airway bleeding or regurgitation.
- The smallest (37 F) size can only be used in children taller than 4 feet.
These include: (a) Endotracheal tubes, (b) Tracheostomy tubes.
Endotracheal Tubes (ETTs)
Traditionally, uncuffed tracheal tubes were routinely used in children. They are available for both nasal and oral use in various sizes, the smallest being 2 mm ID. In recent years, cuffed tracheal tubes are preferred, mostly in small children, especially in the pediatric ICU and emergency department (Fig. 1.33) (Table 1.11).
Cuffed Endotracheal Tube
- Less gas leak around tracheal tube
- Reduced need to exchange inappropriately sized ETT
- More consistent ventilation
- Ventilation with higher inspiratory pressure possible
- Decreases risk of aspiration
- Less use of oversized uncuffed tube
Table 1.11 Size of ETT and Depth of insertionAgeWeight (kg)Size (mm)Depth (cm)Premature newborn< 12–2.57< 3 months1-2383-9 months2-33.59> 9 months
- Low flow anesthesia
- More reliable end-tidal carbon dioxide monitoring
- Reduces atmospheric pollution.
- Cuff hyperinflation leading to tracheal mucosal injury
- Risk of post extubation stridor
- Reduced ID of tube—higher resistance and work of breathing, difficulty in suctioning
- Frequent cuff pressure monitoring is required
- Subglottic stenosis.
Ultra thin high-volume, low-pressure polyurethane cuff results in lower sealing pressure than the conventional cuff. There are considerable differences in the outer tube diameter for a given ID and in length of cuff from different manufacturers. A pressure of 20 cm H2O is sufficient to provide a seal without compromising tracheal mucosal blood flow, which is compromised at 30 cm H2O and completely obstructed at 45 cm H2O.
When the child's age is unknown, the tube size approximates to the external diameter of distal phalanx of little finger or diameter of external nares. Age is recognized as the most reliable indicator of appropriate ETT size selection.
ETT half a size larger and half a size smaller than calculated should be available as well. Cuffed ETT should always be half size smaller than the above calculated uncuffed diameter.
Depth of insertion (cm) oral:
- 3 × ETT (ID in mm)
Rule of 7–8–9–10 in infant (depth of insertion at lips):
The desired depth of a nasotracheal tube is 20% more than oral tube. The practical formula is simplified as nasal tube depth = oral depth + 2 cm.
SPECIAL TYPES OF ETT
Cole Tube (Fig. 1.34)
Its distal portion (2.5-4.5 cm) is smaller in diameter than the rest of the tube. It is sized according to the ID of the tracheal portion. The shoulder (transition from oral to laryngotracheal portion) protects against inadvertent bronchial intubation. It cannot be used nasally as the larger segment will not pass through the nares. It is recommended for resuscitation but not long-term intubation.
Flexometallic Tube (Armoured/Reinforced/Spiral Embedded Tube) (Fig. 1.35)
These tubes have nylon or metal spiral reinforcing wire covered internally and externally by rubber, PVC or silicone. The spirals may not extend into proximal or distal ends. They are available in both cuffed and uncuffed forms.
- Resistant to kinking or compression
- Portion of tube outside can be angled away from surgical field.
- Requires a forceps or stylet for intubation
- Nasal insertion may be difficult
- Length cannot be shortened, so leads to increase in dead space
- Tendency to dislodge from secured position
- Not suitable for ventilation beyond operating room as once compressed due to teeth-bite, does not revert back to normal, so increases resistance to breathing
- Cuff deflation or failure of cuff to deflate.
- Prone position
- Head and neck surgery
- Surgery on trachea
- Patient with tracheostomy undergoing anesthesia.
Preformed Tube (Ring-Adair-Elwyn Tube/RAE Tube) (Figs 1.36A and B)
Both cuffed and uncuffed versions are available for oral or nasal use. As the diameter increases, the distance of the bend from distal tip also increases. There is a mark at the bend which should be at the teeth or nares when ideally positioned. Oral tubes (south pole tube) are shorter and have the bend at an acute angle so that it rests on patient's chin when positioned. A nasal preformed tube (north pole tube) has a curve opposite to oral tube; the outer portion is directed over the patient's forehead.
- Easy to secure and less chance of accidental extubation
- Breathing system connected away from surgical field.
- Difficulty in passing suction catheter
- More resistance than conventional tube
- When inappropriately sized it may lead to bronchial intubation or accidental extubation.
- ENT surgery
- Dental surgery
- Plastic surgery.
Parker Flex-tip Tube (Pft Tube) (Figs 1.37A and B)
It has a “hooded” curved, flexible tapered tip that points towards the center of the distal lumen on the concave surface of the tube so that the bevel faces posteriorly. It reduces the gap between the fiberscope and inside of the tube. There are Murphy eyes on the right and left side of the tube. The tube cuff is very thin. The PFT tube is available in both cuffed and uncuffed version.
- Easier to advance over intubating guide or fiberscope
- Less likely to impinge on vocal cord.
Hi-Lo Jet Tracheal Tube (Fig. 1.38)
This specially designed tube has a main lumen for ventilation, an insufflation lumen integrated within the tube wall for delivery of jet ventilation and a distal monitoring/irrigation lumen used to monitor airway pressure, sample respiratory gases and irrigate the airway. It is used specifically for high frequency jet ventilation (HFJV) in neonatal/pediatric surgery.
The outer diameter of this tube is 0.8 mm larger than the conventional tube with same internal diameter. Thus, a 2.5 mm conventional tube has an outer diameter of 3.5 mm whereas the outer diameter of a similar triple lumen tube is 4.3 mm, which limits its use in infants weighing less than 900 gm. It is available in sizes starting from 3.0 mm onwards.
Options for One-Lung Ventilation
- Single lumen ETT
- Bronchial blocker
- Double lumen tube (DLT).
Single lumen ETT: The conventional single lumen ETT is intentionally pushed into the right or left main bronchus. For left bronchus to be intubated, the bevel of ETT is rotated 180° and the head is turned to the right (Table 1.12).
- Simple, requires a fiberscope to confirm
- Preferred technique in airway hemorrhage or contralateral pneumothorax.
- Failure to achieve adequate bronchial seal in case of uncuffed ETT leads to incomplete collapse of operated lung or failure to protect the healthy lung from contamination.
- Hypoxia from obstruction of upper lobe bronchus, when the right bronchus is intubated.
Bronchial blockers: Because many children are too small for DLTs, different bronchial blockers are often required for single-lung ventilation (SLV) in pediatric patients.
- Balloon-tipped bronchial blockers (Fig. 1.39)
- Fogarty embolectomy catheter
- End-hole, balloon wedge catheter
- Univent tube
- Arndt bronchial blocker.
- Balloon-tipped bronchial blockers
- Fogarty embolectomy catheter: Its placement is facilitated by bending the tip of the stylet towards the bronchus on the operative side. Fiberscope is used to confirm or reposition for appropriate placement.
- End-hole balloon wedge catheter: The bronchus on the operative side is initially intubated with an ETT. A guidewire is advanced into that bronchus through the ETT. The ETT is then removed and the blocker catheter is advanced over the guidewire into the bronchus. The ETT is reinserted into the trachea along the side of the blocker catheter.
Table 1.13 Balloon wedge cathetersSize (F)Length (cm)Maximum inflating volume (cc)Inflated balloon diameter (mm)Guidewire size (inches)5600.7580.0256601.0100.03571101.25110.038The catheter balloon is positioned in proximal mainstem bronchus under fiberoptic visual guidance (Table 1.13).
Advantage of balloon-tipped blockers: More predictable lung collapse with optimal operating conditions is achieved than an ETT in bronchus.
- Dislodgement of blocker balloon into trachea
- Being low-volume and high-pressure, overdistention can damage or rupture the airway
- With close tip bronchial blockers, operated lung cannot be suctioned and CPAP cannot be provided.
- As bronchial blocker is firmly attached to main ETT, displacement is less likely than other blocker techniques
- High torque control blocker can block either left or right bronchus
- Easier to insert and position correctly than a DLT in difficult intubations because of its reduced bulk and anatomic angulation
Table 1.14 Univent tubeSize-ID in mmOD (sagittal/transverse) in mmAge recommended (years)3.57.5/8.06–104.58.5/9.010–14610.0/11.014–166.510.5/11.516–18
- Can be used for postoperative ventilation
- Possible to use suction, apply CPAP, insufflate oxygen through blocker lumen.
- Failure to achieve adequate bronchial seal
- Not recommended for children < 6 years of age
- Fixed shape causes difficulty in sliding over bronchoscope
- Does not soften in warm water bath
- Small lumen gets easily blocked by blood or pus
- Low volume high pressure cuff may cause mucosal injury
- Larger outer diameter makes it difficult to pass between cords.
- Arndt bronchial blocker (wire-guided endobronchial blocker, WEB) (Figs 1.41A and B): It is designed to be used with a single lumen ETT already in place. It consists of two parts: a blocking catheter and a special airway (multiport) adapter. A 5F blocker can be inserted through ETT #x2265; 4.5 mm ID. The innovative guide loop at the end of Arndt blocker's silicone balloon enables precise placement with a pediatric bronchoscope. Both bronchoscope and blocker can be introduced simultaneously through the multiport adapter while maintaining ventilation.
- Can be used in already intubated or tracheostomized patients
- Has been used successfully in infants and small children
- Allows larger internal cross-sectional area than a DLT or Univent tube of similar OD
- May require fewer insertion attempts than a DLT
- If the wire is removed, the lumen can be used for suctioning or administering oxygen or CPAP.
- Once the wire loop is removed, it cannot be reinserted through the channel to allow repositioning of blocker
- Placement requires availability of fiberscope and skill to use it
- Takes longer to position and achieve complete lung collapse compared with Univent or DLT
- Balloon may get sheared while being removed from blocker port.
Double-lumen tube (dlt) (Fig. 1.42): It consists of a shorter tracheal tube and a longer bronchial tube moulded together. Technique of insertion is the same as in an adult and requires a fiberscope to confirm placement. Left DLT is preferred to right DLT (Table 1.15).
- Ease of insertion
- Suction and CPAP with oxygen possible.
- Often too large for small children
- Rigidity and width makes intubation difficult
- Tube malposition from head movement and surgical manipulation
- Trauma to the respiratory tract
- Needs to be changed in case of requirement of post-operative ventilatory support.
TRACHEOSTOMY TUBES (TT) (Figs 1.43A to C)
Various types of TT are available for intended use (Table 1.16).
- Cuffed, uncuffed or fenestrated
- Single cannula or double cannula
- Metal, plastic or silicone.
Plastic and silicone tubes are increasingly popular due to less weight and less crusting of secretions. Fenestrated tube has an opening that permits speech through the upper airway when the external opening is blocked. It is not recommended for small children as the opening can get obstructed with granulation tissue. The silicone tracheostomy tubes are available with air cuff or foam cuff and adjustable neck flange or extended connect.
Indications of Tracheostomy
- Congenital or acquired airway obstruction (i.e. Pierre Robin syndrome, subglottic stenosis, tracheomalacia)
- Long-term ventilation
- Neuromuscular diseases.
ALTERNATIVES TO CONVENTIONAL RIGID LARYNGOSCOPY IN CHILDREN
- Gum elastic bougie aided endotracheal intubation
- Lighted stylet aided endotracheal intubation
- LMA/ILMA/LMA-C Trach aided endotracheal intubation
- Indirect rigid fiberoptic laryngoscope assisted endotracheal intubation (i.e. Bullardoscope/Glidescope/Truview/C-MAC)
- Flexible fiberoptic aided endotracheal intubation
- Invasive airway access
- Emergency needle cricothyrotomy
- Transtracheal needle jet ventilation
- Retrograde intubation
Endotracheal Tube Guides
A number of ETT guides including stylets, introducers and airway exchange catheters (AECs) have been used to aid intubation. The stylets and introducers are always an adjunct to direct laryngoscopy to provide directional control when the laryngeal inlet is not completely visible. A blind technique with these guides, even through the LMA, in difficult airway situations should be avoided (Table 1.17).
Depending on the structure and principle involved they can be broadly divided into two types (Table 1.18):
- Light wand (stylet with built-in light source): Functioning is based on transillumination of the soft tissues of the neck, does not require visualization of larynx, i.e. Trachlight
- Intubating FO stylet (malleable stylet with built-in fiberscope and light source): based on visualization of larynx, i.e. SOS, FAST, etc.
Lighted stylets are portable, light-weight, easily cleaned and sterilized. They produce less sympathetic stimulation than direct laryngoscopy. The possible complications are minor airway trauma, arytenoid subluxation or instrument disarticulation that may be overcome by newer sturdier integral bulbs or FO bundle.
Indication: Difficult airway where fiberscope is unavailable or predicted to be difficult because of blood or secretions in the airway.
- Upper airway tumor or foreign body
- Retropharyngeal abscess
- Infection with friable tissue along intubation course
- Laryngeal injury
- Subglottic stenosis.
Caution: Transillumination may not be useful in emaciated or extremely obese children.
Technique: After lubricating the distal end of trachlight (TL) an ETT with a tube connector is loaded on. The tip of the stylet of TL should remain just inside the ETT without protrusion and locked with a clamp. The ETT-TL unit is shaped to 90°-120° “hockey-stick” at 3-6 cm from the distal end (i.e. just proximal to the cuff). The OR light is dimmed. In supine with head in neutral or sniffing position, perform jaw-lift and insert ETT-TL in midline to advance gently in a rocking motion. If resistance is felt, the TL is rotated backward, then the tip is redirected towards the thyroid prominence using the ‘glow’ as a guide. The initial well-circumscribed light just above the thyroid cartilage changes to a cone-shaped light projecting caudally at the suprasternal notch when it passes the vocal cords. Then the stylet is retracted 10 cm and the ETT-TL is advanced until the glow disappears at the sternal notch. Following the release of the locking clamp, the trachlight is removed from the ETT. In infants and small children, the feel of the lightwand is as important as the visual part.
A click is often felt when the ETT/stylet is advanced past the epiglottis. It is easier to pass a slightly smaller ETT than the maximal age predicted diameter.
A laryngoscope enables medical practitioners to approach the larynx, vocal cords, trachea and adjacent structures and provides a lighted view of the airway. Its use is primarily for inserting an endotracheal tube by intubating the trachea and also for examination of the throat to evaluate diseases of the larynx such as infection, congenital defects, growths, etc.
Laryngoscopy can be divided into: (a) Direct laryngoscopy, (b) Indirect laryngoscopy.
- Direct laryngoscopy: It is a technique wherein the vocal cords are visualized using a handle with a detachable blade such as the Macintosh (curved) or the Miller (straight) blade. Choosing the correct size laryngoscope blade is critical to successful endotracheal intubation (Table 1.19) (Figs 1.52A and B). The tip of Macintosh blade is placed in the vallecula and lifts the base of the tongue, thereby indirectly lifting the epiglottis for visualization of the vocal cords. The Miller blade directly lifts the epiglottis by being placed posterior to the epiglottis, so it is preferred in infants and younger children who have a large, floppy epiglottis (Figs 1.53A and B). Excessive cricoid pressure should be avoided as it results in collapse of airway structures during intubation.The best conventional laryngoscopic view is dependent on the optimal positioning of the patient, an experienced practitioner with capable assistance for optimal external laryngeal manipulation (OELM) and backward upward right pressure (BURP) maneuver if required.
Table 1.19 Size of laryngoscope bladeMiller BladeAge GroupMacintosh BladeSizeLength (mm)SizeLength (mm)0065Premature neonate075Term neonate0801102Infant1872155Child2108
- Indirect laryngoscopy: The vocal cords are visualized through an optical or electronic imaging system. Modifications of the traditional laryngoscope blades are primarily designed for difficult airway situations such as limited mouth opening, anterior larynx, sternal space restriction, small intraoral cavity and unstable cervical spine. The most recently developed blades suitable for pediatric use are:
- Truview evo2
- Bullard elite laryngoscope
- C-MAC video laryngoscope
- Airtraq optical laryngoscope.
- Truview evo2 (Figs 1.54A and B): This rigid, indirect laryngoscope has a unique blade tip angulation which provides a wide and magnified laryngeal view at 46° anterior refracted angle.It has an integrated optical lens and an attachment for connecting oxygen (2-5 liters/min) which provides insufflation, prevents misting and improves safety. The narrow blade tip is suitable for a small mouth.In the neutral position the laryngoscope is inserted centrally over the tongue or from the right side of the mouth, pushing the tongue to the left while visualizing through the optical eyepiece. First the uvula is seen, then the epiglottis becomes visible after advancing a little further. Here the blade can be used as MAC or Miller blade to lift the epiglottis and view the vocal cords. The endotracheal tube over the provided stylet is advanced along the side of the blade till seen in the eyepiece.Then the ETT is advanced slightly upwards and to the left toward the tip of the blade to pass the cords. The ETT is further advanced into the trachea after removing the stylet.Available in 2 sizes:
A new generation upgrade called Truview PCD is available in total 5 blade sizes out of which size 0, 1, 2 are for pediatric use.Advantages
- Infant size (1-10 kg)
- Adult size (>10 kg).
- Effective in all intubation grades
- Requires little or no neck movement
- Reduced force required.
- Glidescope (Fig. 1.55): This videolaryngoscope consists of a laryngoscope blade with a high-resolution digital camera in the middle of the tip of the blade and a LCD light source embedded along the inferior border. The blade is curved at 60° angle to match the anatomical alignment and the camera aids in video-assisted intubation by providing an outstanding view of the supraglottic area on the high-resolution display unit to the viewers. The overall thickness of the blade is reduced to 18 mm and it has an embedded anti-fogging mechanism. Midline approach is essential. A styletted ETT provides the needed curvature for insertion. It is available in 3 sizes—neonatal, pediatric and standard. The latest version called Cobalt uses a disposable blade and has an infant size with a smaller (10 mm) laryngoscope blade for use in neonates.
- Bullard elite laryngoscope (Fig. 1.56): This indirect rigid fiberoptic laryngoscope combines the benefits of rigid direct laryngoscopy and fiberoptic intubation. It is available in three sizes – neonate - infant, child and adult. Its anatomically curved blade requires minimal mouth opening for insertion. Unlike in the adult Bullard, tip or blade extender is not used in children. Its power source can be a conventional laryngoscope blade with batteries and a halogen bulb or a fiberoptic light source attached through an adapter. It has a bifurcated channel: one working channel for oxygen insufflation, suction, instillation of local anesthetics or saline, passage of an airway exchange catheter or jet ventilation catheter and the other channel accepts the dedicated, non-malleable stylet.Two stylets are available for use:
Its eyepiece is at 45° angle from the handle and can get attached to a video camera for remote viewing.Recommendations for use: Six methods of intubation have been described. The blade-stylet assembly with premounted tracheal tube should be inserted into mouth in perfect midline over the tongue with the handle horizontal without looking through eyepiece. Then the handle is made vertical as it slides over the tongue to reach the pharynx. Here, for the first time the viewer has to look through the eyepiece to view the epiglottis and lift it directly or indirectly to slide the ETT over the introducer into the glottis.Advantages
- Introducing (intubating) stylet: It follows the blade contour to reach the field of vision at the 4 o'clock position. It facilitates the passage of the tracheal tube into the laryngeal inlet.
- Multifunctional stylet: It is a long, hollow tube which follows the blade contour when attached. Its hollow core guides the flexible fiberoscope, tracheal tube exchanger or small catheter to instill local anesthetic into trachea. Its maneuverability is much less than the introducing stylet.
- Requires neutral head position
- Can be used for rapid sequence intubation in experienced hands
- Cheaper than fiberscopes, while indications are the same
- Quicker than flexible fiberoptic intubation
- Less trauma and discomfort in awake patient than direct laryngoscopy.
- Requires skill and experience
- Expensive compared to conventional laryngoscope
- Takes slightly longer than conventional laryngoscopy
- Special tubes like DLT or laser tube cannot be inserted
- View less panoramic than regular intubation
- Not useful in distorted upper airway anatomy or foreign body obstruction or blood and secretions in the upper airway.
- C-MAC video laryngoscope: This video laryngoscope can be fitted with laryngoscope blades that are similar to Macintosh 1 or 2 blade and Miller 0 or 1 blade and are applicable in premature neonates (Figs 1.57A and B). This unit is available with LCD monitor of 2.4” screen size which is movable via two rotation axes and rechargeable Li-ion batteries. It is light-weight, compact and very easy to use even by less-experienced practitioners.
- Airtraq optical laryngoscope: Unlike other laryngoscope, it provides a channel for directing the ETT through the vocal cords. It is available in a variety of sizes, i.e. infants (gray), pediatric (pink).The relatively large blade height (12-13 mm) precludes its use in infants with limited mouth opening.
Special Airway Techniques
- Flexible fiberoptic intubation
- Retrograde intubation
FLEXIBLE FIBEROPTIC INTUBATION (FFI) (Figs 1.58A AND B)
Flexible fiberoptic bronchoscopy remains the mainstay of airway assessment and difficult airway management. Indeed, it has become an integral part of neonatology, pediatric pulmonology, anesthesiology, critical care, laryngology and cardiothoracic surgery. The fiberscope is available in different sizes (Table 1.20).
- It is less traumatic as it is manipulated under vision
- It can be used orally or nasally for both upper and lower airway problems.
- It requires skill and experience
- In case of abnormal anatomy, FFI may be impossible especially under deep sedation.
Diagnostic and treatment modality in airway management
Key-points for Procedure
- The discrepancy between the OD of scope and ID of ETT should be kept to a minimum to prevent the ETT from getting stuck at the arytenoids while railroading over the scope.
- For diagnostic bronchoscopy, the scope size should not be more than two-thirds of the diameter of the trachea as the patient has to breathe around the scope.
- The neonatal fiberscope lacks a working channel which generates adequate suction. While using this scope secretions must be aspirated with a normal suction catheter. The neonatal fiberscope has very delicate ultra-thin optic fibers which get easily damaged and requires more skill to control.
- During the oral approach in infants, the scope needs to make an acute anterior bend to approach the anteriorly placed laryngeal inlet, this problem is mitigated during nasal intubation.
- The vocal cords in infants are slanted anteriorly, so it is ideal to approach the anterior commissure at the inlet and then make an acute posterior deflection to enter the trachea.
- For FFI, the ETT is loaded on the scope before endoscopy and the tube is advanced after positioning the scope just above the carina and without having any slack on the scope.
- If the child's trachea is too small for available scope, the suction channel of bronchoscope is used for passage of an extra-long J-tip guidewire into trachea under direct vision while the fiberscope sits above the vocal cords. The scope is then removed and the ETT can be advanced over the guidewire into the trachea. Alternatively, a stiffening device such as a ureteric dilator or Cooks airway exchange catheter can be railroaded over the guidewire. Next, the guidewire is removed and position of the catheter is confirmed by capnography. Then an ETT can be railroaded over the stiffening device (However, the adult size fiberscope cannot be used in infants for railroading technique).
- In case of any resistance during advancement of the ETT, it should be withdrawn and twisted 90° in counter-clockwise direction to make the tip free from the arytenoid cartilage. Reinforced ETT are preferable to minimize this problem.
- Unlike in adults, an awake technique is not preferred in children since cooperation is required to gain a clear bronchoscopic view. A variety of regimens have been used for maintaining spontaneous ventilation in children undergoing FFI. Premedication with atropine helps to dry up secretions. Benzodiazepine with a relatively smaller dose of narcotic are preferred. Midazolam and remifentanil are the ideal agents for sedation as they are short acting and can be reversed with flumazenil and naloxone respectively. Ketamine and propofol are the most commonly recommended anesthetics, often supplemented with local anesthetic instillation and volatile anesthetics.
- Nasal FFI is easier but nasal bleeding is a disadvantage and cannot be used in situations as cleft palate or adenotonsillectomy where oral intubation is required. Otherwise, the approach remains a personal preference.
- Fiberscope through the LMA as a conduit and ventilation device is safe in neonates and infants.
- Rescue techniques such as placing a retrograde guidewire through the suction channel may be employed if the glottis cannot be located with the scope or if blood and secretions are present. Once the fiberscope reaches the trachea, the ETT can be advanced. When the fiberscope is introduced through the LMA as a conduit, LMA has to be of split type or shortened or telescoping the tube over fiberscope is to be done to remove the scope and LMA. Telescoping involves pushing the tube of choice onto a larger one which acts as a holding device while removing LMA and scope without accidentally pulling out ETT.
- FFI should be used early as an aid in a difficult airway scenario as presence of blood or secretions limit its use.
- Absolute – lack of time
- Relative – blood and secretions in oral cavity, edema of tongue, pharynx.
Retrograde intubation is an excellent technique for securing a difficult airway for both elective and emergency situations either alone or in conjunction with fiberscope and a tube exchanger. The technique is simple with a high success rate and should be a skill practiced by every anesthesiologist.
- Restricted cervical spine mobility
- Airway trauma.
Cricothyroid puncture is done with a small catheter-over-needle device with an attached syringe with cephalad angulation. A flexible J-tip guidewire (0.021 inch diameter, 140 cm) or an epidural catheter is introduced through the catheter to exit spontaneously through the mouth or nostril (in cases with difficult mouth opening, suction can be used to retrieve the retrograde catheter). The catheter at the cricothyroid membrane is removed and the guide is clamped at the skin. The guidewire can be threaded through the ETT or AEC or working channel of a fiberscope sheathed with a reinforced ETT. The scope and tube assembly or AEC can be advanced following the wire through abnormal and collapsed tissues. Once the tip of the scope gets just below the vocal cords, the guidewire is removed with caudad traction. Then the scope is threaded into the distal trachea and ETT is slid into place. The airway exchange catheter will allow patient's oxygenation as well as confirmation of tracheal placement by capnography. The ETT can then be advanced over AEC.
- It may not be suitable for immediate intubation and ventilation as the procedure may take time for completion.
- It may cause bleeding at the skin-puncture site, pretracheal abscess.
- Trauma to the airway is possible, especially in infants, because of the poorly defined cricothyroid membrane and the proximity of the vocal cords to the puncture site.
Cricothyrotomy is a life-saving procedure in CVCI situation. It can be performed by 3 techniques.
- Needle cricothyrotomy
- Percutaneous dilatational cricothyrotomy
- Surgical cricothyrotomy.
Needle cricothyrotomy with small catheters of at least 4 cm length with percutaneous translaryngeal ventilation (PTLV) is quicker, simpler and safer than the other two techniques. The jet ventilation catheter is available in 3 sizes (babies, children and adults). Catheter length is important, because if too short, it may come out and gas will escape into the subcutaneous tissue of the neck. It is essential for every emergency physician to be familiar with the indications, contraindications, techniques and complications of this type of rescue airway.
Indications: “CVCI situation”
- Facial or cervical trauma, uncontrollable oral hemorrhage
- Oropharyngeal edema from infection, anaphylaxis or chemical inhalation injuries.
- Trismus or anatomic variants
- Rescue from profound hypoxemia during FFI under deep sedation, followed by urgent tracheostomy.
- Where nasal or oral intubation possible and safe
- Acute laryngeal trauma or infection
- Obstruction at or below the cricoid level, as the obstructing element may get pushed deeper
- Avoided if patient recently intubated
- Inability to locate the cricothyroid membrane
- Upper airway obstruction not allowing the gas to escape.
- Identify the cricothyroid membrane in the midline between thyroid and cricoid cartilage. Prepare skin with betadine.
- Next use a large 12-14 G angiocath (catheter over needle) with syringe directed at a 45° angle caudally to puncture the membrane.
- Once air is aspirated into the syringe, remove the needle from angiocath while advancing the catheter smoothly in a caudad direction, taking care not to perforate the posterior tracheal wall.
- Confirm the position of the catheter by air aspiration with a syringe.
- Then attach the catheter hub to an oxygen source or jet ventilator through an appropriate connector.
This technique is a temporary measure which allows 30-40 minutes of uninterrupted oxygenation and ventilation while allowing unhurried access to secure the airway. Significant barotrauma is a risk with tracheal jet insufflation. A high-flow oxygen source and an adequate expiratory time are the appropriate ventilatory parameters to limit barotrauma.
- Exsanguinating hematoma
- CO2 retention in spite of adequate oxygenation
- Perforation of esophagus, posterior wall of trachea, thyroid gland
- Inadequate oxygenation
- Subcutaneous or mediastinal emphysema
Percutaneous Dilatational Cricothyrotomy (PDC)
This technique uses the Seldinger method to gain access to the cricothyroid membrane. The track around the guidewire can be enlarged by using serial dilators to accommodate the cricothyrotomy tube which may have a cuff. There are a number of commercial kits available. For example, Quicktrach 2 mm for children, Arndt emergency cricothyrotomy cath set (9F/6 cm length, coil reinforced kink- resistant catheter with a standard 15 mm connector and luer-lock) (Fig. 1.59).
In this technique a transverse incision is made through the cricothyroid membrane using a scalpel, through which an ETT is inserted. It should be performed rapidly when equipment for less invasive technique is unavailable. It is a more definitive airway than the PDC.
Tracheostomy may be defined as establishing transcutaneous access to the trachea below the level of cricoid cartilage.
- Emergent—acute airway loss in <6 yr of age where the cricothyroid space is too small for cannulation
- Elective—distorted laryngeal anatomy, prolonged ventilatory support.
Percutaneous dilatational tracheostomy is not recommended in the pediatric age group as the tracheal tissue is markedly elastic in children. Pressure applied on the anterior tracheal wall during dilatation of stoma can cause compressive obstruction of tracheal lumen and increased chance of perforation of the posterior wall of the trachea.
Translaryngeal tracheostomy is preferable in children as its approach is retrograde and requires minimum pressure on the pretracheal tissue and trachea. Under bronchoscopic guidance, insertion of a J-shaped wire percutaneously in the trachea passes retrograde into the mouth. The specially designed conal dilator with tracheostomy tube is threaded over the guidewire and pulled through the oral cavity, larynx, trachea and out through the anterior tracheal wall. Then the cone is removed and TT is rotated from a cephalad to caudal direction by using an obturator and then advanced caudally to its final position. During the procedure, the trachea is ventilated with a small diameter tracheal tube positioned co-axial to the original airway and its distal end is positioned distal to tracheostomy site. The ETT is removed after or just before rotation and securing of tracheostomy tube. Since dilatation is achieved by tracheal cannula itself (tracheal rings are simply divaricated), it fits snugly with the wound edges. This newer technique is safe in children and specially beneficial in coagulopathic babies.
The subcricoid region has the advantage of absence of bleeding as no major blood vessel is present on the cricotracheal membrane and also reduction in possible development of subglottic edema and stenosis.
Surgical tracheostomy is more invasive. In the supine position, maximal extension of the head and neck is done with a towel roll. A 1 cm transverse skin incision is made in the second tracheal ring. The incision is dilated and deepened. A longitudinal tracheal incision is made over the second and third tracheal ring and a tracheostomy tube is inserted through the opening. The tracheal cartilage should not be excised as this leads to stricture formation. A metal tube is avoided. Ideally intubation should be done prior to tracheostomy unless an obstructive lesion precludes its use. Sedation and analgesia is strongly recommended to minimize movement of the head and neck for 3-5 days.
Management of a difficult airway is a fundamental part of clinical practice. Fortunately, the incidence of unexpected difficult pediatric airway is low since most of them are associated with congenital syndromes.
Recognizing a difficult airway is thus the first step in handling these cases. A detailed preoperative evaluation and accordingly a plan of action of how to proceed with the available resources and equipment, usually prevents a CVCI situation. A child's airway anatomy may get modified with growth or get worsened in some syndromes, thus a previous successful intubation does not guarantee success in the future. Airway assessment is very difficult in an uncooperative child. Every child's airway should be evaluated in the lateral profile. A full and frank discussion of the risks with parents (and child if appropriate) and the possibility of tracheostomy and indeed, of failure to secure the airway should always be mentioned.
Preparing these patients is the next step. Premedication and duration of preoperative fasting plays an important role in preventing a crying child, as upper airway obstruction worsens when the child cries or struggles and generates a greater negative intrathoracic pressure. Premedication with atropine is recommended, to dry up secretions and to prevent bradycardia associated with airway manipulation.
COMMON CAUSES OF DIFFICULT AIRWAY
- Congenital craniofacial abnormalities
- Maxillary hypoplasia: Apert syndrome, Crouzon disease
- Mandibular hypoplasia (micrognathia): Pierre-Robin syndrome, Treacher-Collins syndrome, Goldenhar syndrome, Nager syndrome
- Mandibular hyperplasia: Acromegaly, Cherubism
- Temporomandibular joint ankylosis: Congenital, mucopolysaccharidoses (MPS)
- Microstomia: Ludwig's angina, burns, trauma scarring, hemangioma tongue, Freeman-Sheldon syndrome.
- Macroglossia: Down's syndrome, hypothyroidism, MPS, Beckwith-Wiedeman syndrome
- Nose: Narrow nares due to MPS, choanal atresia
- Pharynx: Hypertrophic tonsils and adenoids, retropharyngeal abscess
- Palate: Cleft palate, soft palatal swelling
- Larynx: Glottic-laryngomalacia, MPS, Infraglottic- congenital stenosis, MPS
- Neck-vertebral anomalies: MPS, Klippel-Feil anomaly.
Any of the above can lead to a difficult airway due to:
- Difficult access, i.e. limited mouth opening, obstruction by soft tissue mass
- Difficult to visualize, i.e. small mandible with less submandibular space to accommodate tongue.
- Challenges on target tissue, i.e. inspite of glottic visualization, unable to ventilate or intubate as in foreign body trachea or laryngeal tumor.
MANAGEMENT STRATEGIES (FIG. 1.60)
The principles of airway care in the adult population are applicable to pediatric patients. However, the techniques available in adult care may not be available because of size and technological limitations.
- The degree of cooperation in the pediatric age group is variable, so awake intervention may not always be an option.
- Loss of patency of child's airway rapidly results in hypoxemia and desaturation due to a low FRC with a high basal oxygen consumption. Oxygen supplementation throughout the intervention is critical in children.
- In certain cases, mask ventilation is difficult but airway access via LMA or ETT is achieved readily. In such situations, an attempt with LMA insertion or tracheal intubation should be a prudent first intervention.
- A patent airway is the ultimate goal, hence direct laryngoscopy attempts must not be persistent because of associated morbidity and mortality and other choices should be offered as an alternative according to algorithm.
- Transtracheal techniques should be considered early if alternate transoral techniques are either not available or do not achieve ventilation.
- Maintenance of spontaneous breathing allows a way out in case of inability to secure the airway. Muscle relaxants should be withheld until the airway is secure and intubation should be preferably be done under deep inhalation anesthesia. In case muscle relaxant has led to a “CVCI” situation, surgical airway should be rapidly accessed.
- For the neonatal difficult airway, the presence of a third competent person is advisable. When bag and mask ventilation, LMA and tracheal intubation all fail to establish effective ventilation, the possibility of a laryngotracheal anomaly calls for an immediate surgical access as the only way to save the baby.
- Planned extubation of a trachea that presented difficulty at intubation, should take place in the presence of not only an experienced laryngoscopist but also a surgeon competent in providing surgical access to the airway.
DIFFICULT AIRWAY CART FOR PEDIATRICS (FIG. 1.61)
One should ideally have all the desired equipment on a designated difficult airway cart. However, it is far more important that the kit contains tools with which the physician is familiar and skilled, than containing a large number of items. All equipment should be clearly labeled and functionally well-maintained.
A Standard Airway Kit
A Standard airway kit should contain as a minimum:
- Face-masks of all sizes and shapes
- Nasopharyngeal airways and oropharyngeal airways- of all sizes
- ETT - uncuffed and cuffed (2.5-6 mm)
- Tracheal tube stylet (6F, 8F)
- Magill forceps—small, medium
- Laryngoscope blades - Miller (00, 0,1,2), Macintosh (0,1,2), short laryngoscope handle
- LMA classic (1,1.5,2,2.5,3), ProSeal (1, 1.5,2,2.5, 3) disposable LMA
- Suction catheters (6F, 8F, 10F, 12F) (Fig. 1.62)
- Manual resuscitation bag (0.5L and 1 Liter)
- Miscellaneous—spare batteries, lignocaine spray, lubricant, bite-block, syringes, decongestant.
A Difficult Airway Cart
A difficult airway cart should contain:
- Lighted stylet (Trachlight) - Pediatric and infant size
- Gum elastic bougie (GEB)
- Airway exchange catheter (AEC)
- Alternative to direct laryngoscope
- Flexible fiberscope
- C-MAC video laryngoscope } Pediatric size
- Transtracheal airway kit - l6/18G IV catheter (1.5-2 inches long jet ventilation device)
- Cricothyrotomy equipment
- Tracheostomy set
- Oxygen source
- ILMA # 3, Combitube (37F).