Chapter 8. Airway

Establishing or maintaining a patent airway is one of the most fundamental lifesaving skills. Despite circumstances, clinicians must be able to secure an airway with limited or unusual equipment. Depending on a single technique or device is potentially dangerous for the patient.1

Positioning for Safe Airway

It is much better to prevent aspiration than to treat it. When there is concern about a patient maintaining his airway, especially if there are copious secretions or vomitus, place the patient in the "rescue" or "recovery" position—on his side with his face aimed toward the bed to prevent aspiration. If possible, also raise the foot of the bed so that the patient is in the head-down position.

Even patients with extensive and penetrating facial injuries may not need endotracheal intubation if they are put into the recovery position.2

If the individual has a suspected cervical spine injury, use the High Arm IN Endangered Spine (HAINES) position (Fig. 8-1). The differences from the recovery position are that the dependant upper limb is fully abducted and lies under the head where it reduces lateral neck flexion, and both lower limbs are flexed at the hip and the knee resulting in one lying on top of the other, possibly reducing torque on the thoracolumbar spine. A single rescuer can easily put a patient in the HAINES position.3

Opening the Airway

Chin Lift/Jaw Thrust

Perhaps the easiest method to maintain an open airway is to simply push the chin up. For somnolent and sedated patients, this is often all that is needed to keep the airway patent. If a cervical spine injury is suspected, push the jaw forward from the mandibular angles.

Head Turn

Head turn is a simple, but rarely used, procedure to open an airway. In patients with significant amounts of redundant tissue in the pharynx and hypopharynx (and no history of possible acute cervical spine injury), simply turn the head to one side to improve airflow.1

Positioning the Tongue

If the patient's tongue still blocks the airway after positioning the head, or if the head cannot be repositioned because of a suspected cervical spine injury, grasp the tongue with gauze and pull it forward. This is a temporizing measure only. For better control over longer periods, put a heavy (~2-0) suture or a wire or suture substitute (such as fishing line) vertically through the tip of the tongue in the midline (Fig. 8-2). Placing it anterior and midline avoids significant bleeding. An assistant can hold the suture or it can be passed through the skin of the lower lip and then tied.4 A towel clip (Fig 8-3) or a safety pin (Fig. 8-4) can also be placed vertically in the midline to hold the tongue. Do not use a clamp or forceps that "may in the excitement of the moment be so firmly applied as to nip a piece out of the tongue."5 Physicians, surgeons, and anesthetists have used these methods since at least the 19th century without complication.6

Opening a Clenched Mouth

If the mouth is clenched and the patient needs to be ventilated, first ventilate through the nose. Try to open the mouth by putting pressure on the temporomandibular joints. If neuromuscular blockers are available and you are comfortable with your advanced airway skills, use them to relax the jaw.

If the patient is apneic with a clenched jaw, press your fingers between his teeth and gums, behind the last molars. This will usually open the jaw wide enough to pass a laryngoscope or to place an airway.

Nasal Airways

A nasal airway, or "trumpet," is one of the most useful pieces of airway equipment. However, for some reason, it is hardly ever used, even though they are easy to improvise.

To make a nasal airway, use any soft piece of rubber tubing that is the appropriate size for the patient's nose and put a safety pin through the end so that it cannot disappear down their nose (Fig. 8-5). Most adults do well if the length of the tube beyond the safety pin equals the length from their nares to the meatus of their ear (4.5 to 5 inches; 11.5 to 13 cm). This device has been termed a "Goldman's nasopharyngeal airway."7 The Goldman's airway can be made to fit any nose. Some clinicians cut an uncuffed endotracheal tube to size; others suture it to the nasal septum (midline between the cartilage and skin) to keep it in place.1

If one nasal airway works, two may sometimes work better. Consider using a "binasal airway"—you need only an extra piece of tubing and a second safety pin or suture. When placing a nasal airway, lubricate it well and pass it along the floor of the nose (straight back, not cephalad).

Pediatric

When intubating children, the two key elements are (a) using the laryngoscope correctly and (b) correctly estimating the endotracheal tube (ETT) size.

No matter what type of laryngoscope is used, the most common reason practitioners cannot intubate a child is that they advance the laryngoscope too far. If the laryngoscope does not immediately produce a view of the cords, keep looking at the larynx and slowly back the laryngoscope out. The epiglottis usually pops into view.

For pediatric intubations, you need to have the correct ETT size. Because cuffed tubes are now being used for most children and for infants other than neonates (and even for some neonates), many of the older formulas for uncuffed tubes don't work. See Table 8-1 for the standard and formula-calculated sizes for cuffed and uncuffed pediatric ETTs. The size of a cuffed tube to use will be smaller than for an uncuffed tube, since the tube itself does not need to occlude the airway: only the balloon has to occlude the airway. Keep cuff inflation pressure <20 cm H2O to avoid tracheal necrosis.

The ETT should be inserted to a distance (in centimeters) equal to (10 + age in years) or (3 × ETT size) at the lips. Table 8-2 gives the placement for newborns.

Adult

Adults have anatomical, physiological, and situational issues that may complicate intubation. However, improvised solutions are available, as described below.

Special Situations

Most intubations won't be dramatic. However, patients may be in a variety of unusual positions, especially in out-of-hospital situations. Knowing some alternative positions to use for intubation can lessen the stress.8

Seated Vehicular Entrapment

When patients are trapped in a sitting position, face the victim when managing the airway. Even in this position, if bag-valve-mask (BVM) or mouth-to-mask ventilation is necessary, an adequate mask seal may be difficult to achieve. If a controlled airway is necessary and the patient is still breathing, use blind nasotracheal or digitial intubation (see descriptions under "Non-laryngoscopic Intubation" in this chapter), a Combitube, a laryngeal mask airway (LMA), retrograde intubation (often unsuccessful), or a cricothyrotomy. If the patient has lost muscular tone and can no longer bite down, use digital intubation. If a patient is not breathing, perform an "inverted" intubation by holding the laryngoscope handle toward the patient's lap and visualizing the glottis from the front. It may be easier to perform this maneuver by using the laryngoscope in the nondominant hand and guiding the tube with the dominant hand.

For a patient strapped into stretcher with rigid sides (e.g., Stokes basket), straddle the patient and face him, then do the intubation as with a seated vehicular entrapment.

Difficult Airway—What Next?

If the patient is difficult to intubate, stop trying and return to using bag-and-mask ventilation. The maximum time allotted to intubate should be no longer than the time you can hold your breath; patient who need intubation can't hold their breath that long. If you can use a BVM to ventilate the patient, use that to buy yourself time to consider any adjuncts or procedures that may help you to intubate.

If you are unable to ventilate the patient despite using the adjuncts mentioned, consider trying one of the airway methods described in the following paragraphs and call for help. If none of these is an option, wake the patient if appropriate (such as in the operating room [OR]) or prepare for an emergency cricothyroidotomy.

Poor-Man's Laryngeal Mask Airway

The Poor-man's LMA consists of blindly passing a cuffed ETT (of the appropriate size to intubate the patient) into the oropharynx so that the cuffed portion of the tube lies between the tongue and the posterior pharyngeal wall (Fig. 8-6). Insert the ETT with the balloon fully inflated. Then the operator pinches the patient's nose closed and seals the lips around the tube, while the assistant bags the patient through the tube in the normal fashion.9 This does not work as well as a normal LMA, so replace this with another airway method as soon as possible.

Transtracheal Ventilation

Although transtracheal ventilation (TV) seems like the perfect solution for the problem airway, as with many of the improvised methods suggested in the literature and in protocols, it simply does not work, at least not in adults.10 The method is discussed here, since it may work in children and because so many protocols still include it. To be assured of success, use this method only in very small children, and do a surgical cricothyrotomy on everyone else who needs this type of intervention.

The problems with doing a TV are (a) placing the needle/catheter correctly, (b) preventing the catheter from kinking, and (c) obtaining adequate flow through the catheter. So, the guiding principle is that if the cricothyroid membrane will be violated in austere circumstances, use a knife, not a needle.

For TV, the needle/catheter can be placed in either the cricothyroid space or the trachea. Determining where to place the needle can be daunting for those not familiar with the process. The key is to find the midline. (See "Cricothyrotomy" in this chapter for more details.)

Catheters

The catheters used for jet ventilation range from 14 to 18 gauge in both adults and children. Special catheters that don't kink have been used for most tests of TV. But most clinicians use 14-gauge IV catheters for the procedure, and these standard over-the-needle IV catheters may kink at their hub due to the acute angle as they pass into the trachea.11 This may be ameliorated somewhat by holding the catheter at its hub.12

An alternative is to use a larger (13-Fr/ >4-mm outside diameter [OD]; 9-Fr/3-mm internal diameter [ID], ~6 inch) catheter, which is about the same size as an ETT for a newborn (12-Fr/4-mm OD; 2.5-mm ID). These catheters generally are used as central lines or as "introducers" for large lines. While they may not provide much better oxygenation or ventilation than a 14-gauge catheter, the polyvinyl chloride structure and the length provide enough strength to prevent collapse and decannulation. It also avoids the catheter slipping into the subcutaneous space where, if the oxygen is being delivered under pressure, it can result in a massive buildup of subcutaneous air, leading to collapse of the tracheal lumen and death.13 A real benefit is that these catheters also can be easily turned cephalad and used to do a retrograde intubation.14

Flow

Once the catheter is placed and functions, the real problem begins: how to oxygenate/ventilate the patient without a standard transtracheal jet ventilator. The basic parameter to consider is that a 70-kg patient requires a flow rate of >1100 mL/second to be adequately ventilated. The only makeshift method that supplies this flow through a 14-gauge catheter is to use unregulated wall oxygen that delivers about 1400 mL/second at about 65 psi. (This is not oxygen from a "wide-open" regulator: that delivers only about 350 mL/second.10) This can be controlled using a simple "Y" device in the tubing connecting the oxygen source and the patient (Fig. 8-7). When using this device, occlude the opening for 1 second to allow inspiration and release it for 3 seconds during expiration.15 Additionally, in the OR, the catheter can be connected to the "oxygen flush valve" on the anesthesia machine; this is essentially a jet ventilator.16 To do this, connect stiff tubing to the common gas outlet with a standard 15-mm ETT connector. Most modern machines, however, are fitted with a safety valve to prevent overpressure and therefore may not be suitable for this purpose.17

The danger when using an unregulated oxygen source is that it can cause barotrauma to the lungs. However, adequate jet ventilation is just that—ventilation. The high flow rate not only supplies oxygen, but also forces CO2 out of the lungs.18 It also appears to protect against aspiration as well as a cuffed ETT.19

How about connecting a 15-mm ETT adapter and using a BVM? This has been suggested repeatedly in the literature and in medical protocols. Any IV catheter can be attached to a 3.5mm ETT adapter, although removing the adapter from the tube may require cutting it off, since they are very firmly attached. An easier method is to insert a 6.5- to 8.5-mm cuffed ETT into a 5, 10-, or 20-mL syringe barrel, inflate the balloon, and connect the syringe to the IV catheter. The ETT provides the 15-mm BVM adapter.20

The problem then is that ventilating with a BVM is not only physically challenging, but also quickly results in hypercarbia, even when a 4-mm ID catheter is used (about three times the ID of a 14-gauge catheter). Therefore, unless a jet ventilator, unregulated wall oxygen, or an anesthesia machine's oxygen flush valve is used, consider TV a temporizing method not to be used for more than a few minutes. In most cases, this makes it not worth the trouble. Use another method!

Intubation is probably used far too often in Western tertiary care centers, and not often enough elsewhere. However, ask yourself why you are not intubating a patient who

• Tolerates an oral airway
• Is too agitated to fully evaluate and cannot be easily or safely sedated
• Is not oriented to time, place, person, and events after head trauma
• Is not maintaining, or may not be able to maintain, a patent airway
• Cannot or may not be able to handle their secretions without aspirating
• Has had an acute mental status change

Many of these patients do not need intubation immediately. In these cases, ask yourself: Why am I not intubating this patient now? Make a conscious decision to either intubate them or carefully observe them.

Suction Device

It is possible, and often necessary, to remove airway debris manually with your fingers or by sucking it out with a bulb syringe or large-mouth (Toomey) syringe. However, the best option for long-term use is to build a simple foot-operated suction device (Fig. 8-8). One way to do this is to modify an automobile or truck tire pump so that its valves suck instead of pump. Attach this to two wide-mouth unbreakable 1-L bottles, and then to the sucker.21

Improvised ETTs

Many tubes can be used as uncuffed endotracheal, cricothyrotomy, and tracheostomy tubes in emergency situations. The wide variety of medical tubing available in hospitals and clinics offers the benefits of cleanliness and various degrees of flexibility. For example, connector tubing for suction devices and chest tubes are useful for this purpose. Even though very large urethral catheters could be used for infant ETTs if their tips are cut off, their soft rubber walls may collapse. Some polyvinyl tubes and heavier rubber tubes offer less flexibility than others (e.g., chest tube). Typical chest tube sizes (OD = ETT size) that work appropriately as ETTs are 10 Fr (3.3 mm), 12 Fr (4.0 mm), 16 Fr (5.3 mm), 20 Fr (6.7 mm), and 24 Fr (8.0 mm). Cut any tube to the appropriate length before use.

Any hollow tubing that can go through the airway also can be used as an ETT, at least temporarily. If the tube is straight and rigid (like a rigid bronchoscope), such as a small pipe or a piece of bamboo, the patient must be kept fully sedated and, if possible, paralyzed, to avoid breaking the teeth or causing other trauma. The patient must also be in a condition to have his head extended (i.e., no neck injury).

The biggest problem with makeshift ETTs is how to connect them to a BVM or a ventilator. Whatever tubing is used, and no matter what size is needed—from neonatal to large adult—the tube can quickly and easily be adapted to fit a standard ventilator or bag-valve connector using the technique described in the following section.

ETT Adapter

If an alternative tube is used as an ETT, if the standard ETT you have does not fit the ventilation device being used, or if the standard adapter that fits the ventilation device is lost or broken, a simple fix is at hand. Made from the nipple of a standard infant feeding bottle, this adapter is similar to a Foregger-Racine adapter and other more-complex equipment described for the same purpose.22 Enlarge the nipple hole so that the ventilator end of the ETT can just fit through with a tight seal. Push the tube through the hole so that the BVM/ventilator end is inside the nipple. The other (bottle) end of the nipple connects to the ventilation device (Fig. 8-9). Experience shows that any size pediatric or adult ETT, or any equivalent that is being used as a makeshift endotracheal, cricothyrotomy, or tracheostomy tube, will fit.23

Improvising an ETT "Cuff"

ETTs work best if they are cuffed. If an ETT (regular or improvised) is not cuffed or if its balloon breaks, there may be a significant air leak, which may increase the chance of aspiration. In those cases, pack the pharynx under direct vision with a wide piece of gauze or cloth, using Magill or similar forceps. As when packing the nose or an abscess, use only one length of packing material so that, when it is removed, there is no chance of leaving an unobserved second piece behind. Tie one end of the packing to the ETT to ensure its removal at the end of the operation.7 Use saline-soaked gauze or cloth for this. Don't use petroleum jelly (e.g., Vaseline) or other petroleum-containing products to soak the gauze, since that might cause pneumonitis.24

Fixing an ETT

If a polyvinyl ETT is torn, the best solution is not to use it. If it is already in place, replace it. However, if this is not possible or is too dangerous for the patient, two temporizing methods exist: (a) To quickly seal a small hole, put a moist sponge over it. (b) For a more permanent seal, use a small amount of cyanoacrylate (i.e., Super glue, Dermabond) to immediately and completely seal the hole. Before using the glue, thoroughly dry the torn portion of the tube so that it will seal properly.25

Stylet

Stylets are invaluable for keeping an ETT in the shape desired by the intubating clinician. But when stylets are used repeatedly, especially those used for neonatal intubations, they can break at their tip from constant bending.26 To make an improvised stylet, take a piece of any malleable wire and put it into a nasogastric (NG) tube or a small urethral catheter. Voilà! A stylet.

A coat hanger slips into a 12-Fr NG tube, thus producing stylets for ETTs size 5 and above. Fashion stylets for smaller tubes using smaller NG tubes. These can be easily resterilized for repeated use.27 Alternatively, batches of stylets can be made from copper wire that is the appropriate diameter for the ETT in which they will be used.

To keep a tube rigid without using a stylet, and if time is available to wait, put the ETT in ice water. Freezing it also works. This tends to work better for smaller caliber ETTs. (Written communication from Daniel Tzse, MD, Brown University, received June 5, 2007.)

Makeshift Laryngoscope

Transillumination with Makeshift Laryngoscopes

The problem with laryngoscopes is that either their light doesn't work or doesn't exist when you need to intubate a patient urgently. In these cases, use either the dead laryngoscope or an alternative made from a tongue depressor, shoehorn, spatula, or spoon. If using a nonmalleable improvisation, use it to extend the tongue out of the mouth as far as possible, or grasp and pull the tongue to achieve the same result. The larynx should be visible if illuminated. A spoon handle can be bent to act as a laryngoscope blade to facilitate this view (Fig. 8-10). Illuminate the larynx, either directly through the mouth (e.g., pen light, operating room light) or transillumination through the cricothyroid membrane using a portable light (e.g., pen light, headlamp).28–30 Boulton wrote that "the larynx is seen as a brightly illuminated area in a black field."7 John C. Sakles, MD, a colleague at the University of Arizona who has used the transillumination method, commented, "It is extremely dark in there. Not much light gets through. Red light works best." (Written communication, September 5, 2008.)

Homemade Laryngoscope

Gillett and Patkin developed and used an inexpensive laryngoscope constructed of simple materials for situations where standard laryngoscopes are too expensive or are simply unavailable (Fig. 8-11).

The handle is made of oak or beech, and two penlight batteries are attached to it by Sellotape [heavy clear tape] or by two light aluminum bands. At one end they are held by the blade, and at the other by a small piece of Perspex [acrylic glass; Plexiglas] which bears a simple pivot switch. The blade is of twin-track aluminum from which one of the three flanges have been removed entirely, while the other two have been partly cut away towards the tip. It is shaped by bending in a heavy vice. In the track that is left there is an inexpensive prefocused torch bulb with a lead soldered to its base. The rest of this track has in it some hard rubber tubing about this lead, and this stops the metal of the blade knocking on to the upper teeth or the gum when the instrument is in use. The bulb lies in a shallow hammered recess. The blade is held on to the wooden handle with two strong chrome screws.31

This device costs almost nothing to make and, "in a well-equipped workshop an inexperienced person can make a batch of these instruments at the rate of two an hour." This laryngoscope was successfully used on 88 patients in its initial trial.31 Similar inexpensive laryngoscopes have been made at other small hospitals.32

Laryngoscope Problems

If the laryngoscope light fails to work, it may be due to a loose or faulty bulb, dead batteries, or an electrical problem. First, tighten the bulb; this is the most common problem. Second, clean the little pins (contacts) on both the blade and the handle. (These meet to complete the electrical circuit for the light.) A pencil eraser should work, but the contacts may need to be scraped with a sharp-edged implement. Third, insert fresh batteries. Fourth, replace the bulb, remembering that light bulbs for laryngoscopes come in large and small sizes that are not interchangeable. Having a spare light means having one that not only works, but also fits the laryngoscope blade you are using. Finally, if the laryngoscope is still not working, check the electrical pathway with an electrical meter.

Electrical problems may be caused by corrosion from disposable batteries. Remove them (but not rechargeable, nickel–cadmium batteries) if the laryngoscope will not be used for a few days. If corroded batteries are stuck in the handle, boil the handle in a pan of water to try to loosen them. If not, use a large drill to remove them, being careful not to drill deep enough to damage the contact at the top of the handle. Then clean the inside of the handle and make it as neat as possible.33

To quickly provide a light source for the laryngoscope, place a cystoscope, arthroscope, or any other small fiberoptic scope into the groove of a Miller blade or through the introducing hole in a Macintosh blade (Fig. 8-12). Then use the blade in the normal fashion.34

If the chrome is peeling off the laryngoscope, it may seem to be a mundane problem—until the sharp edge cuts a patient. Use a scalpel blade to carefully remove loose chrome. Then use fine sandpaper (an emery board or a nail file also work) and some water to smooth the remaining chrome. When done, check that it is smooth by running cotton over it; any rough edges will catch the cotton.33

Blind Nasotracheal Intubation

The only tools necessary to do a blind nasotracheal intubation are an ETT (called a nasotracheal tube [NTT] for this procedure), skill, and a breathing patient. Attempt the procedure only in patients who are spontaneously breathing; the patient's exhalations are the guide to placing the tube. Patients can be either awake or not awake. The technique can be performed in a controlled manner; clinicians experienced in this technique have a success rate of about 90%. Neophytes often use the "push-and-hope" (not using exhalations as a guide) method, which actually works about 40% of the time.35,36

Procedure

Before beginning the procedure, wipe the connector and the tube with alcohol and firmly push the connector at the end of the tube into the long part of the tube; it is surprising how many times the connector and tube come apart and the tube has to be "fished out" using the pilot balloon.

To do this procedure, anesthetize both nostrils thoroughly using a local anesthetic. In an emergency, simply lubricate the tube. If there is time (at least 8 minutes) and it is available, 4% cocaine is the optimal drug since it is an excellent anesthetic/vasoconstrictor. Position the patient's head in a neutral position—with the patient supine (usual) or sitting (in severe congestive heart failure). With firm, steady pressure, introduce the tube—about 0.5 to 1 mm smaller than would be used endotracheally—through the nose and into the nasopharynx. As when placing an NG tube, the NTT goes straight back into the nose, not up. At that point, resistance lessens and the breath sounds through the tube become a little harsher.35

Once in the nasopharynx, patience and skill are necessary to place the tube properly. While watching the patient's chest for exhalation and putting an ear next to the tube to hear exhalation, push the tube 0.5 to 1 inch each time exhaled breath is heard and felt through the tube. If this exhaled air is not heard or felt each time after the tube is advanced, back up the tube the same amount it was just advanced, reposition the tube (by twisting) or the patient's head (generally, more flexed), and advance it a small bit again. If the patient coughs, the tube has hit the vocal cords and should be quickly pushed into the trachea. Often, this does not occur, and the tube is fully advanced to its hub (a normal position for a nasotracheal intubation) with breath sounds still being heard. That means it has been successfully placed. Another indication of success is that the patient cannot speak. Patients with severe congestive heart failure often seem to suck the tube into their trachea. These are the easiest patients on whom to perform this procedure. Asthmatics, with their poor breath sounds, are the most difficult.35

Teaching/Learning the Technique

A model37 has been devised to teach this technique by using an intubating head model with one of the "lungs" removed and replaced with a BVM to simulate breathing (Fig. 8-13).

Improving Nasotracheal Intubation Success Rate

Boggy Balloon

Once the tube (the same tube is used for endotracheal and nasotracheal intubation) enters the oropharynx, inflate the cuff with 15 to 20 mL of air (Fig. 8-14). Then, when a slight resistance is felt as the cuff contacts the vocal cords, deflate the cuff and advance the tube into the trachea. This technique has up to a 95% success rate but often only after three attempts (which is not unusual in blind nasotracheal intubations).38–40

Lighted Tube

This method, a forerunner of the lighted stylet, can easily be improvised. Using an insulated wire, attach a small bulb from a pediatric laryngoscope to a laryngoscope handle or other low-voltage electrical source. Put the wire through the NTT until it just barely protrudes from the end; mark that spot on the wire with tape. Next, insert the tube into the pharynx and insert the light through the tube up to the taped line. This positions the bulb just past the tip of the tube. In a darkened room, the tip of the tube can be visualized, and you will see if it goes off midline. If the light vanishes, it is in the esophagus. To prevent aspiration, bulb must be tightly secured to the wire. This method could also be used for oral intubations if the stylet is run through the ETT next to the wire. In that case, either tie the stylet to the wire or remove the stylet first, so that the light does not pop off and get aspirated.

Nasogastric Tube Used as a Guide

If the NTT seems to be at the larynx (coarse breath sounds are heard or the patient coughs when the tube is advanced) but won't pass through it, hold the NTT in position and pass an NG or suction tube through it (Fig. 8-15). This should easily go into the trachea. Then, withdraw the NTT slightly and either pass it into the trachea over this "guide" or remove it and pass a smaller tube over the guide.41–43 Another option that can be used simultaneously is to rotate the tube to move the tip off the arytenoid cartilage.

Is the Tube Going into the Right Place?

To detect breathing through the tube during blind nasotracheal intubation, cut a finger from a rubber glove and attach it to the end of the tube. Cut a small hole in the other end. It will give you "the finger" as it fills with each exhalation (Fig. 8-16). Once the tube is in the trachea, remove the glove finger quickly, or the patient will become hypoxic and hypercarbic.

Digital/Tactile Intubation

This technique, used since the 18th century, has the clinician palpate the larynx while guiding the tube into it.44

Adult Digital Intubation

As with blind nasotracheal intubation, digital intubation requires only the ETT and experience with the technique. As opposed to blind nasotracheal intubation, these patients are (preferably) not breathing and have no gag reflex (and no ability to bite the clinician's hand). Clinicians commonly complain that their fingers are too short, their hands are too large, or the patient's mouth is too small to do digital intubation successfully. This is not true. Experience has shown that most in-hospital and prehospital clinicians can use this method to digitally intubate a majority of adult, pediatric, and neonatal patients. With minimal instruction, physicians and emergency medical service (EMS) personnel have been able to successfully intubate ~90% of patients using this method.45,46 One benefit of the procedure is that it can be performed with only an ETT and, preferably, a stylet and gloves. Other benefits are that c-spine immobilization can be maintained and that the clinician is not at the head of the bed where other activities may be occurring.

Reasons to use this method include being unable to visualize vocal cords with a laryngoscope (copious secretions, structural abnormality, technical reasons); no (or a nonfunctioning) laryngoscope; cramped quarters; apnea during blind nasotracheal intubation; both intubation and cervical immobilization are required; or it is a clinician's preferred intubation method.45,47,48

To perform digital intubation in an adult or an older child, position yourself on the patient's RIGHT side, and slide the volar surface of your LEFT index and middle fingers over the base of the tongue into the hypopharynx. Drag down the corner of the mouth until the epiglottis can be palpated with both fingers and, if necessary, flipped up. Before advancing the tube with your right hand, push the intraoral fingers farther into the hypopharynx, posterior to the larynx (Fig. 8-17). Your fingers then act as a "backstop" for the tube—forcing it anteriorly through the glottis as it advances. Flexing the index finger may help guide the tube through the glottis. If a stylet is used, acutely flexing the tip of the tube anteriorly improves the success rate. If the patient is able to bite your fingers during the procedure, use a bite block between the molar teeth.45,47,48

Pediatric/Neonatal Digital Intubation

Digital intubation has been successfully used in neonates for more than 75 years. Since neonates are edentulous and have a shorter distance to their airway than adults, the procedure is both less risky and potentially easier.

To do the procedure, stand on either side (or at the head or the feet) of the child, holding an ETT with or without a stylet. (Most clinicians initially prefer using a stylet.) Put a slight bend in the end of the tube. Moisten the index finger of your left hand and put it into the pharynx beyond the epiglottis, so that the fingertip lies behind and superior to the larynx and the nail touches the posterior pharyngeal wall. In a limp newborn infant, the epiglottis feels like a band running across the base of the tongue. Moisten the ETT tip with saline and, holding it like a pencil with the right hand, pass it over your finger until the tip lies in the midline of the distal phalanx. Use the index finger to shift the catheter until the tip is just above and in line with the glottic opening. At that point, with the index finger still in place, put your left thumb on the infant's neck just below the cricoid cartilage, in order to grasp the body of the larynx between your thumb and finger (Fig. 8-18). While the thumb and finger gently steady the larynx to prevent side-to-side motion, the right hand advances the tube through the glottis for a distance of about 1 cm. You will feel a slight give or tightening as the catheter passes the glottis, but no force is needed for insertion. If the tube slips into the esophagus, it can be felt between the finger and the larynx. Leave your finger in the infant's mouth to maintain tube position during resuscitation.

Most infants weighing more than 2 kg, and many as little as 1.5 kg, can be intubated using this method, although the clinician may need to use his small, rather than index, finger. This method can also be used for tracheal suctioning, changing ETTs and quickly reintubating an accidentally extubated baby. It can be done anywhere, even in cramped quarters, so neither the child nor other equipment needs to be moved, and the clinician does not have to stoop or bend to do the procedure.49,50 Experienced practitioners can do this in a few seconds.

Retrograde Endotracheal Intubation

Retrograde intubation can be used to obtain a controlled airway when other methods have failed or to convert a needle cricothyrotomy into an orotracheal intubation. The technique is very useful when all else has failed, but it can also be used as a planned procedure (Fig. 8-19). It can be done with only basic equipment. Contraindications are few, but include infection, the presence of a large hematoma or tumor in the area, and clotting disorders. Unlike fiberoptic bronchoscopy, the presence of blood in the airway does not hinder the procedure.17

As with a number of other airway procedures, a question that naturally occurs is: If the cricothyroid membrane has been identified and will be violated, why not simply open it and introduce the endotracheal or tube, which is a much simpler procedure for most clinicians?

Procedure

Do a cricothyroid puncture using a 12- to 16-gauge needle, with the bevel facing cephalad to help direct the wire toward the oropharynx. Attach a syringe to aspirate air and confirm positioning in the trachea. It is important to make sure that the needle used is large enough to allow the guidewire to pass through it easily; using a central intravenous line kit works well. An IV over-the-needle catheter may kink and thus not allow the guidewire to pass, even if it is an appropriate diameter. Once the needle is positioned, the syringe is removed and the guidewire is passed through it toward the oropharynx.

Whatever retrograde guide is used, it must be at least twice the length of the ETT, and preferably longer. It may be an epidural catheter or a vascular guidewire, such as those used for insertion of a central venous catheter. These are stiffer wires and have a "J" tip that is less traumatic to the airway.

Many other types of makeshift guides have been suggested for this procedure, including central venous through-the-needle catheters or guidewires, and guidewires for several other types of medical procedures. Many of these are too supple to pass easily, frequently become stuck in the soft tissues, make their own false passages, or reverse direction when they strike an obstruction.

When the wire is visualized in the oropharynx, it is pulled out through the mouth with a forceps or, if necessary, with one's fingers. The needle should be removed from the neck and the wire clamped at the insertion point, so an assistant can hold it in place. Some clinicians insert their needle just below the cricoid cartilage, rather than through the cricothyroid membrane. They have found that this location is preferable, partly due to less vascularity, but mostly because it allows a longer depth of insertion for the ETT, which prevents it from dislodging when inserted over the retrograde guidewire.

At this point, one option that may increase the likelihood of a successful intubation is to pass a nasogastric (NG) tube over the wire, after first cutting it to about two-thirds the length of the guidewire and removing any side ports. The NG tube is a stiffer and more reliable guide for the ETT. The guidewire still must remain in place.

If only a guidewire is used, the wire is passed through the distal-side port (Murphy eye) of the tube; if the guidewire–NG tube is used, it passes up through the end of the tube. As the ETT is passed over the guidewire or guidewire–NG tube, it meets resistance, either at the point where the guidewire curves up toward the skin puncture site or at more proximal structures. If the tube is at the point where the guidewire curves toward the skin, trying to advance the tube further pulls on the guidewire at the larynx. If unsure that the tube has passed the vocal cords, withdraw the tube slightly, turn it 90 degrees and advance it again.51

The procedure can be performed on an awake patient after appropriate local anesthesia is applied to the airway. Sedation makes the procedure more comfortable for the patient.

Intubation through a Non-Intubating Laryngeal Mask Airway

The use of an LMA has become a routine practice in the ED, the prehospital setting, and the OR. Often, especially in critically ill patients, the LMA is changed to an ETT for long-term ventilation. This is usually done through an intubating LMA that is specifically designed for this purpose. It uses an accompanying special (and very expensive) ETT.

If the special ETT for an intubating LMA is not available, or if an intubating LMA is not available, intubation can be successfully accomplished with a 6-mm-ID ETT passed through a size 3 or 4 LMA.52 Two difficulties are encountered. The first is that the normal ETTs are not long enough to pass through the LMA and completely through the vocal cords. Standard ETTs are about 28.5-cm long, and need to be about 32 cm to accomplish the task. The solution is to cut a 3.5-cm-long piece of ETT and, using cyanoacrylate, bond the two together (Fig. 8-20). This adhesive should take only a few minutes to dry; test the adhesive and bonding time in advance. The second difficulty is that unlike an intubating LMA, the distal end of the standard LMA has plastic "bars" that impede the passage of the ETT. The solution, opening the web at the patient end of the LMA, requires only a few snips of a scissors.

Once the patient is intubated, the LMA can be left in place with a small risk of soft tissue injury, or it can be removed using a variety of methods. Improvised methods to remove the LMA include using another ETT of the same or slightly smaller size as a buttress to hold the ETT steady as the LMA is withdrawn over it. Once the LMA is partially withdrawn, it is often possible to grasp the ETT in the posterior pharynx to stabilize it.53 A tube changer can also be used to remove the LMA, although if the ETT slips out, it may need to be passed over the tube changer ("railroaded") back into the trachea.54

Exposed Trachea

In cases where an injury to the neck or face exposes the larynx or trachea to direct visualization, an ETT can simply be placed into the airway without any manipulation except for holding the soft tissues away from the hole.

Unanesthetized Intubation

When safety takes precedence over patient comfort, the simplest and safest way to intubate a patient in an emergency, including for emergency surgery,

is with the patient awake, and this is almost always possible with neonates and infants aged less than 2 months, in whom it is the technique of choice. Many adults, especially if they are sick, will also tolerate intubation while awake if you explain what you intend to do and why. Use a well-lubricated laryngoscope blade, and insert it gently and slowly. When you can see the larynx (it may take a minute or two) pass the tracheal tube through it, trying not to touch the sides of the pharynx on the way down, as this may make the patient gag and you will have to start again. On intubation the patient will probably cough, and your assistant may need to restrain the patient's hands. Immediately after intubation, you can safely [sedate the patient or] induce anesthesia.55

Experience has demonstrated that it is almost always possible to at least use local anesthetic on awake patients before intubating them orotracheally using the methods described below.

Oropharyngeal Anesthetic

One of the safest ways to intubate orally is by using local oropharyngeal anesthetics. These can be applied via gargle, spray, or inhalation.

Cooperative patients can gargle 30 mL of 2% to 4% lidocaine as either a topical liquid or a mixture of the liquid and viscous forms. Gargling is best done in three or four stages, using a portion of the 30 mL for each gargle, with the patient spitting out the residual anesthetic after each gargle to avoid excessive drug exposure. Allow at least 1 minute between gargles for the anesthetic to take effect. Local spray anesthetic can be used before and after the gargles.56

Oral intubation can be done (carefully) after locally anesthetizing the posterior tongue, palate, uvula, tonsillar pillars, and the posterior pharynx. This can be done using a commercial lidocaine aerosol spray (10 mg per spray), up to 3 to 4 mL of 2% lidocaine, or with a similar anesthetic using an improvised atomizer (see Figs. 13-5 and 13-6) or syringe and blunt needle or plastic IV catheter. (Be careful not to overdose the patient.) The key is that local anesthesia takes a few minutes to act; don't hurry. Lidocaine, for example, takes about 1 minute to take effect when applied to the mucosal surface, has a peak effect in 2 to 5 minutes, and lasts between 30 and 45 minutes.56

Initially direct the spray onto the mouth and throat. After careful laryngoscopy, spray additional anesthetic onto the laryngopharynx, larynx, and trachea. Anesthetize the area below the cords, if necessary, by spraying the area using a curved hollow stylet under direct vision.56–59 Inhaling lidocaine can quickly produce anesthesia in the nasopharyngeal cavity, pharynx, larynx, trachea, and nose. (See Chapter 25, Otolaryngology [ENT], for more details.) Experience shows that this is also an excellent and safe technique to use for direct laryngoscopy, either for examination or for foreign body removal.

Transcricoid Anesthesia

Transcricothyroid or transtracheal injection is an excellent method of anesthetizing the whole tracheobronchial tree for intubation or endoscopy—especially in emergency situations. Patients are told to hold their breath while a 21- or 22-gauge needle is inserted either through the cricothyroid space or immediately above the cricoid cartilage. Aspirate air to ensure proper position, immediately inject 2 mL of 4% lidocaine, and remove the needle. For the patient to tolerate this, it must be done rapidly. The patient will immediately cough due to the presence of the lidocaine, spreading the analgesic up and down the trachea. Anesthesia reaches the superior aspect of the cords in 95% of cases.60 Intubation is often possible after this procedure alone. If necessary or if bronchoscopy is to be done, also spray the laryngeal structures as described in the preceding text. Contraindications include neck infections.61–64 Complications are very rare.56,65,66

Detecting Esophageal and Endobronchial Intubations

Unrecognized esophageal and endobronchial intubation cause significant morbidity and mortality. While sophisticated (and expensive) devices have proven reliable at recognizing this, clinicians may often be in situations in which they must use alternative methods (Table 8-3).

Listening over both the upper abdomen and the lungs during ventilation provides a reliable method for determining whether the ETT is in the lungs. Listening over only the lungs results in mistakes 15% of the time.68 Alternatively, the ETT can be advanced into the right mainstem bronchus while listening for unilateral breath sounds. This test is somewhat less useful, since it provides accurate identification only 91% of the time. It can, however, be a useful adjunct to other methods.69 If the ETT is not placed into the trachea correctly, withdraw it to its proper position above the carina after the test.

For those comfortable with using a gum-elastic bougie for intubation, the clinician can confirm tracheal placement by passing the bougie through the ETT and feeling, at ~30 cm, its "hockey stick" end pass over the tracheal rings, which is sometimes described as "a hold up" of the bougie.70

An in-line stethoscope inserted between the ETT and BVM has also been used successfully to determine esophageal versus tracheal intubation (Fig. 8-21). To make this device, remove the bell and diaphragm (head) from an ordinary stethoscope. Cover the end of the stethoscope tubing with a finger cot or the finger cut from a surgical glove; tape it on tightly so that it forms a new diaphragm for the stethoscope. Insert the covered tubing end into an airway connector normally used for fiberoptic bronchoscopy. The stethoscope fits where the bronchoscope normally enters. Connect the ETT to the connector at the distal end; the other end goes to the BVM.

When placed in-line during ventilation, the stethoscope allows the clinician to assess the type and quality of sounds in the system. When using the device, give six breaths to the patient. An ETT in the trachea produces loud breath sounds with a rapid decrease in volume during the expiratory phase. Esophageal intubation is indicated by an absence of sound or by the presence of squeaks, flatus-like noises, or any sound heard in expiration that does not rapidly decrease in volume. This device is accurate 95% to 99% of the time. It can also be used to monitor patients during helicopter transport and, since it is less invasive than the esophageal stethoscope, to monitor patients during surgery.71

Esophageal Detector Devices

The simple and reliable esophageal detector devices (EDD) can generally differentiate esophageal from tracheal intubations. EDDs aspirate air through the ETT, using the differences in tracheal and esophageal anatomy to indicate tube placement.72,73 If air can be aspirated easily through the tube, it is in the non-collapsible trachea; failure to aspirate air means that the tube is in the collapsible esophagus.

The two major nonelectronic EDDs are a syringe type (Fig. 8-22) and a bulb type (Fig. 8-23). The syringe-type EDD is made by using a short length of rubber tubing attached to a 60-mL catheter-tip (Toomey) syringe using a right-angled ETT connector, such as is found at the end of a BVM. The Mapleson C (anesthesia) disposable breathing system also contains soft plastic adapters for wall-mounted oxygen delivery that can form the connection.70

A baby bottle nipple also works well as a connector from the ETT to the syringe. Enlarge the hole slightly in the nipple and insert the syringe toward the nipple's wide bottle-end opening. Slip the bottle-end opening over the ETT; it fits perfectly.

A mechanical EDD must be airtight to work correctly. Test it by occluding the open end with a finger and pulling back on the syringe plunger. If you feel resistance or a negative pressure, it is ready for use. Once the device is joined to an ETT, use the syringe to aspirate. An esophageal intubation usually causes resistance when the syringe is aspirated and the esophagus collapses with the negative pressure; the plunger usually rebounds to its original position when released. Aspirating 30 mL of air without the plunger rebounding when released generally indicates a tracheal intubation.72,73

A simpler way to construct an EDD is to attach a self-inflating rubber bulb (such as may be used for newborn suctioning) directly to a right-angled ETT connector (Fig. 8-23). Cut the suction end to accommodate the attachment. Squeeze the bulb and attach it to the ETT. Rapid passive reinflation indicates a tracheal intubation. When placed on a tube that is in the esophagus, it fails to reinflate due to esophageal collapse with the negative pressure, often producing a "flatus-like noise."74

The advantages of EDDs are that they: (a) can be easily and inexpensively constructed with commonly available equipment, (b) are both portable and reusable, (c) do not require electricity, (d) are easy to use in-hospital or prehospital settings with minimal instruction, and (e) produce highly reliable results rapidly, even during resuscitation efforts after a cardiac arrest.75

The disadvantages of EDDs include both false-positive and false-negative results, although the incidence of either is extremely low.76 False-positive results (showing that the ETT is in the trachea when it is actually in the esophagus) are due to the regurgitation of gas from the stomach, esophageal distension with gas, or an EDD with a leak. False-negative results (showing that the ETT is in the esophagus when it is actually in the trachea) can occur when thick secretions block the ETT, when the end of the ETT is occluded by the tracheal wall, in obese patients, or with bronchial intubation, bronchospasm, tracheal compression, and chronic obstructive pulmonary disease.75

The devices are unreliable in infants <1 year old, although they work well in children ≥2 years old, even when using uncuffed tubes.77,78 In children, use the device before any breaths are given through the tube, since extra air in the esophagus or stomach can give a false result. Only 10 cc should be aspirated if using a syringe device. Begin with the syringe plunger at the 10-mL mark, rather than at "0," to avoid an initial suction effect from the syringe.77

Securing the ETT

When securing an ETT, carefully note the depth, so that if the tube slips, it can be repositioned correctly.

Interdental wiring (small-gauge wires or wire sutures) or heavy silk sutures can be used to secure ETTs in place. This becomes particularly useful in patients with severe burns or injuries to the face. Loop a wire around an anterior tooth, usually an incisor, and twist it until it is tight. A needle holder or pliers helps to hold the wire ends when tightening them (Fig. 8-24). Then loop the free ends of the wire around the ETT and twist it until an indentation is noted in the tube.79 When using a heavy ("0") silk suture, remove the needle and tie the suture very tightly around the base of the tooth. Tie in the ETT as with the wire suture, but add an additional tie on the ETT. A problem with using a silk suture is that it may break with intraoral manipulation, or it may slide down the silastic ETT, predisposing to unplanned extubation.80

Suctioning an ETT

If an ETT suction catheter is not available, use a number-10 rectal tube. This size works well for adult ETTs.7

Tube Changer

ETTs may need to be changed due to leaking cuffs, the tubes being too small, or inspissated secretions causing partial obstructions. Simply repeating the intubation may be a daunting task, especially if the airway has become edematous, the original intubation was difficult, or the clinician is inexperienced.

To lessen the chance that a problem will occur during the change—such as not being able to reintroduce the tube into the trachea—a tube changer can be used. A tube changer is a long guidewire, coated with a lubricant, which passes through the ETT currently in place and into the trachea. After preoxygenating the patient, pass the guidewire through the ETT and into the trachea. Carefully remove the ETT tube so the guide is not displaced. Then, gently elevate the jaw and slide the replacement tube over the guidewire into the trachea. If the tube gets hung up, back it up slightly, rotate it 90 degrees, and advance it again.

Tube changers are normally gum-elastic bougies. Multiple pieces of equipment have been used as tube-changing guides. These include NG tubes with the flared ends and side ports cut off, feeding tubes, radiology catheters (such as for angiography), or any piece of wire at least 2.5 times as long as the ETT. If a wire such as an unwound wire coat hanger is used, cover it with an NG tube or double over the ends of the wire to avoid cutting the tissues. Bend the wire to conform to the ETT that is in the patient. Cut off the "twisty" end of a coat hanger (the part that cannot be straightened easily). Success with improvised tube changers varies with their diameter relative to the ETT and on their stiffness.81

Surgical airways, although once common, now are rarely used in emergency situations in developed countries. With their wide variety of intubating medications and sophisticated airway devices, clinicians usually have no need to apply a knife to the neck to get an emergent airway. Yet, when a patient needs an immediate airway and no other method is practicable, a surgical airway may be the best option. Some type of knife and a tube—even if they are not the optimal choices—are nearly always available. Having to perform a surgical airway is much more likely in austere medical situations than in normal circumstances.

Prediction of Difficult Surgical Airway

A quick assessment can determine whether obtaining a surgical airway may be problematic. These are not contraindications, only observations to suggest that a surgical airway may be difficult. Use the mnemonic "SHORT" to recall what to observe, or to ask if there is sufficient time: Does the patient have (a) evidence of previous neck Surgery? (b) a Hematoma or abscess in the anterior neck? (c) Obesity or other neck enlargement, such as from subcutaneous emphysema or edema? (d) prior Radiation to the neck area? or (e) a Tumor in the neck area?82

In reality, in an emergency, the answers to those questions may not matter; you have to get an airway no matter what the situation. Knowing that these problems exist, however, may sway you toward another airway option, if it is available.

Cricothyrotomy

Cricothyrotomy is lifesaving. "This is an emergency procedure to be done at the site of injury, without anesthesia, with any sharp knife at hand."83

Position

To locate the correct site for a cricothyrotomy, use the "4-finger rule." When you lay the tip of the small finger in the sternal notch, the tip of the index finger lies over the cricothyroid membrane. This works for most adults. For a child, lift their hand to their neck to use their fingers.

Procedure

Emergency cricothyroidotomies have been performed with scissors, pocket or hunting knives, razor blades, broken glass, and the jagged edges of the lid from a tin can. If using a scalpel, simply turning the scalpel blade's handle in the cricothyroid incision is as effective as using an intraoperative Trousseau dilator (the formal piece of equipment used in the OR to dilate the hole for a tracheostomy) to widen the hole to insert the tube. Using a skin hook allows a slightly larger-size ETT to be placed.84 (For a skin hook fashioned from a bent needle, see Fig. 21-5 in Chapter 21, Surgery/Trauma.)

Another method of putting the tube in the trachea is to use the Seldinger technique. As soon as entry is made into the trachea, pass a guide, such as a wire, through it. Then, using the eyehole at the end of the ETT, pass the tube into the trachea.

Hold the Hole Open

Once the cricothyroid membrane is opened, if the patient is breathing spontaneously, such as when an upper airway obstruction has been relieved, the hole only needs to be held open manually. In these cases, the incision through the cricothyroid membrane needs to be slightly larger than normal. Airways also have been held open in these circumstances with paper clips and nail clippers.

Cricothyrotomy Tubes

Endotrachael and Tracheostomy Tubes

Placing an ETT through an emergency cricothyrotomy is optimal. It is easily handled, is readily available in most health care settings, is long enough not to slip out, and has a small enough balloon so that it does not get torn as it passes into the trachea. A tracheostomy tube, if available, is a good alternative, although it is shorter and has a bulky balloon, potentially increasing complications in stressful situations.

Other Tubes

A wide variety of tubes has been suggested; some have even been tested. Some will be available only in health care facilities. Others are designed for use in out-of-hospital austere circumstances. The problem is that some don't work; many are dependent on the object's design and diameter. But in these circumstances, you have to use what is available. While not a sophisticated plan, research does show that in critical situations when a cricothyrotomy tube is needed, it is best to use the largest hollow tube available that will fit through the hole. Be creative.

Syringe Barrel

An excellent cricothyrotomy tube can be fashioned from the flanged portion of a 2-mL or 3-mL syringe barrel cut to 45 degrees (Fig. 8-25). Remove the syringe plunger and cut the barrel at an approximate 45-degree angle, at a point one-third of the way toward the tip (needle end). Insert the cut end of the syringe through the surgical opening at a right angle to the trachea, with the long end entering through the caudal (upper) part of the incision (Fig. 8-26). The flanges on the barrel act as a stopper and provide a site for securing the tube. The problem with this device, as with many other improvised cricothyrotomy tubes, is how to attach a BVM, if one is available. Mouth-to-tube ventilation may be the only option for an apneic patient.85

Sports Bottle Straws

Not only have the relatively rigid and large-bore sports bottle straws been successfully used for emergency cricothyrotomies, but also, when tested, both the ribbed and flat types have about the same airway resistance as do 7.0-mm ETTs and 8.0-mm tracheostomy tubes. They also have the benefit that, if available subsequently, a standard adapter from a 7.0-mm ETT can be inserted, so a bag-valve device can be used without reintubating the patient. Of course, as with all improvised devices, the straw lacks a cuff, so the patient's mouth must be sealed during mouth-to-straw ventilations. It is, however, long and flexible enough to fit into the trachea with enough extra length for the operator to perform ventilations.86

Tubes and Small Hollow Objects

Consider any available hollow tubing as a possible cricothyrotomy tube when doing an emergency procedure. Many small hollow objects also have been suggested, although these are not often used as cricothyrotomy tubes. These include small flashlight or penlight casings, very small pill bottles, plastic throat swabs containers with the bottom cut out, and pen barrels.

Pen barrels have actually been tested. Although they are discussed in medical texts as being useful, at least the standard-issue US military ballpoint pen (Skilcraft, Alexandria, VA) produces so much airway resistance, even with the tapered tip cut off, that it is essentially useless as an airway—except, perhaps as a route for transtracheal jet ventilation or for temporary apneic oxygenation.86

IV Drip Chamber

The drip chamber from either regular intravenous tubing or one part of the "Y" from blood tubing has been suggested as a cricothyrotomy cannula.87,88 The drip chamber is cut ~3 cm distal to the spike that goes into the IV bag/bottle. After cutting through the skin over the cricothyroid membrane (a vertical incision is best if you are not certain of the landmarks), insert the spike through the membrane.89

Although the drip chamber supposedly fits well onto a standard BVM, tests show that it only works with some IV tubing. Even with tubing that is too small to fit well, "V-shaped" cuts can be made on both sides of the drip chamber and the BVM can be forced into or around it. Test this before inserting it into the neck, so that modifications can be made before it is in place. Also, consider attaching the BVM before inserting the tube, since attaching it may require more leverage than is possible once the tube is in place.

Postprocedure Bleeding

Protect yourself, if possible, from the spray of blood that invariably accompanies opening the trachea. If you are midline, you can control any bleeding after the tube is in place by packing the area around it with petroleum jelly-impregnated or other gauze. Sutures or cautery are rarely needed to control this bleeding. If you have strayed off midline, however, you may be into the major vessels of the neck—and won't find the trachea. Use a vertical incision and, once through the skin, feel for the cricothyroid membrane, or use the needle-guided method (as with an emergency tracheostomy, described below) if you are concerned about staying in the midline.

Emergency Tracheostomy

Because of its difficulty and potential complications, a true emergency "crash" tracheostomy should be the last option, but is useful if no other method of establishing an adequate airway is available. An emergency tracheostomy is also useful in children needing an immediate surgical airway, since their cricothyroid area is generally too small for a cricothyrotomy. It is also useful (and the author has used it successfully) for patients in whom massive neck swelling from bleeding or from subcutaneous emphysema obscures the cricothyroid landmarks. The basic principle is to stay in the midline. The following technique provides a solution and has proved easy to learn and to use.

This emergency tracheostomy technique requires only a fluid-filled syringe, a needle, a knife, and a tube. To perform the tracheostomy using this technique90: locate the midline of the neck and secure the trachea between the thumb and index finger of the nondominant hand. Incise the overlying skin transversely. Use a finder needle, attached to a saline (or any nontoxic fluid)-filled syringe, to locate and stabilize the tracheal lumen prior to incision and cannulation. Insert the needle into the midline between the prominent thyroid cartilage and the sternal notch, aiming for the anterior trachea (Fig. 8-27). Inject the fluid gently; when it flows without resistance, the needle has entered the trachea. Aspiration of air confirms correct positioning within the lumen. While holding the needle steady, make a vertical stabbing incision lateral to and against the needle (Fig. 8-28). Using the knife handle to open the stoma, remove the needle and insert a standard ETT (Fig. 8-29). Secure the tube with tape and, if necessary, pack the wound to control bleeding.

Another (slower) tracheostomy method, only appropriate in nonurgent situations, requires some equipment that may not be readily available. Based on the method described previously, it uses the Seldinger (wire-through-needle) technique. With the larynx firmly stabilized with the nondominant hand, make a 1.5- to 2.0-cm transverse or vertical incision just below the cricoid cartilage. Then pass a large-gauge needle through the incision and into the trachea. Optimally, the needle is specifically designed to accommodate the wire, such as with an arterial line or a central line kit. Using a fluid-filled syringe attached to the needle simplifies locating the trachea with the needle, as described previously. Once the trachea is entered, carefully remove the syringe and pass the wire through the needle into the trachea. Pass small (artery-dilating Howard-Kelly) forceps along the wire through the soft tissues of the neck until you feel resistance at the outside of the trachea. Open the forceps to dilate the opening down to the trachea. Then close the forceps and pass them over the wire through the tracheal wall. Advance the forceps until the tip is in the long axis of the trachea; spread the forceps and the tracheostomy tube or, if the wire is long enough, pass an ETT over the guidewire.91,92

Dislodged Tracheostomy Tube

The only sign that the tracheostomy tube is dislodged may be the inability to pass a suction catheter through it, although this can also occur when concretions block the tube.

A mature (>30 days) tracheostomy tube can usually be replaced without too much difficulty if no granulation tissue or foreign body blocks the passage. Simply replace the obturator and pass it into the mature stoma. With tracheostomies <1-month-old, it may be difficult to put a dislodged tube back into the trachea (or trying to do so may cause a false passage) due to stoma closure. In these cases, place an ETT, rather than the shorter tracheostomy tube; a tracheostomy tube can be placed once the airway is again secure.

As a guide, use a urethral catheter with the tip cut off, a suction catheter, or similar tubing connected to an oxygen source. Pass it through the ETT and then gently into the trachea. If the trachea cannot be visualized, pass a pediatric laryngoscope into the trachea, followed by the tube/guide. Once the tube is in the trachea, remove the guide.93

Post-Tracheostomy Bleeding

Post-tracheostomy bleeding can be deadly. While mild incision bleeding is typical 1 to 3 weeks post tracheostomy, 85% of tracheo-innominate artery fistula bleeds also occur in the first month. They have a mortality rate of 80% even with treatment. Post-tracheostomy bleeding is often from granulation tissue in the stoma or trachea, erosion of the thyroid vessels or gland, or the tracheal wall due to overzealous suctioning.94

Methods to help control the bleeding while getting the patient to the operating room or interventional radiology include hyperinflating the tube's cuff, putting mild anterior traction on the tube, or replacing the tracheostomy tube with an ETT and hyperinflating the balloon, which should be placed, if possible, just distal to the site of bleeding to tamponade it. The best technique is to stick one's finger into the stoma and apply local digital pressure to compress the innominate artery. If this doesn't work on one side, go to the other side.95