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Airway Management for the Sports Physician

Part 2: Advanced Techniques

Robert L. Norris, MD; Jeffery Peterson, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 29 - NO.11 - NOVEMBER 2001


This is the second of two articles on airway management for the sports physician. The first, on basic techniques, appeared in October.

In Brief: Airway emergencies sometimes require techniques other than basic management methods. Advanced techniques are needed to manage laryngeal edema or fracture, upper-airway hemorrhage, or other injuries that make ventilation or intubation from above impossible. Placing various endotracheal devices and performing surgical techniques such as needle cricothyrostomy and tracheostomy can be done by physicians who have training and the necessary equipment. Surgical techniques can be performed with medical bag components, but commercial kits are available for those who are uncomfortable performing techniques using bag equipment.

Airway emergencies represent one of the most life-threatening situations that sports medicine physicians face. Responses to most airway emergencies are met using a systematic approach and basic management techniques (see "Airway Management for the Sports Medicine Physician, Part 1: Basic Techniques," October, page 23). Some situations, however, require advanced or surgical procedures. We focus on how to perform advanced techniques, methods for field assessment, and alternatives to deal with complications.

Advanced Techniques

The most secure and effective airway in the seriously ill or injured athlete is a properly placed endotracheal tube (ETT). Placement of a cuffed tube below the vocal cords minimizes the risk of aspiration and greatly simplifies and facilitates ventilation and oxygenation. Many techniques exist for inserting an ETT, including laryngoscopic orotracheal intubation, blind nasotracheal intubation, and tactile or digital intubation.

Orotracheal intubation is the advanced airway technique with which many physicians have the greatest experience and comfort. In experienced hands, the technique is usually very fast, particularly for apneic patients.

Cervical injury. If cervical spine trauma is a possibility, the procedure should be performed with in-line stabilization (figure 1: not shown). While no studies have demonstrated that any airway management technique is safe with concomitant unstable cervical spine injury, oral intubation with in-line stabilization is being used by many trauma care providers with great success (1).

Ventilation. Ventilation is done with a bag-valve mask (BVM) and 100% oxygen (again, using cricoid pressure if possible) while the necessary equipment for endotracheal intubation is prepared. An appropriate-sized ETT is chosen. For most adult males, an 8.0-mm tube is sufficient; for adult females, 7.0 mm. In children, the appropriate size tube can be calculated by the formula: (age in years + 16) ÷ 4. Alternatively, a child's tube size should be approximately the size of the child's little finger. In children younger than 8 to 10, anatomic narrowing of the airway at the level of the cricoid cartilage obviates the need for a cuff on the ETT. Use of a cuffed tube in these patients may lead to mucosal damage and secondary tracheal stenosis (2). In older children, in whom cuffed ETTs are appropriate, cuffs should be inflated and checked to ensure integrity. A lubricated stylet with a slight anterior distal bend should be placed in the ETT to aid in maneuvering the tube through the vocal cords.

Preparing the laryngoscope. In addition to the ETT, the laryngoscope and blade (figure 2) are prepared. The scope should be checked to be sure the light is operational. The standard laryngoscope is held in the operator's left hand. If the glottis is not visible because of an anatomically anterior larynx, the rescuer can use his or her right hand to apply backward, upward, and rightward pressure to the larynx (the "BURP" maneuver) to bring it into view. Alternatively, an assistant can "BURP" the larynx while the laryngoscopist passes the ETT. Once the glottis can be seen, the tip of the ETT is passed between the cords, and the stylet is removed.

[Figure 2]

The ETT can then be advanced to the appropriate depth. In an average-sized adult, the tube should be positioned so that the anterior teeth or alveolar ridge lie between the 19- and 23-cm indicator marks (3). Pediatric tubes are often marked with distal black lines designed to be placed at the level of the cords during intubation. The depth of insertion can also be estimated by multiplying the internal diameter of the tube by 3 (eg, 5.0 X 3 = 15 cm at the incisor teeth) (3). The cuff (if appropriate) is then inflated and the tube's correct position checked using one of several techniques (table 1). After proper positioning is confirmed, cricoid pressure can be safely released.


TABLE 1. Methods for Assessing Proper Endotracheal Tube Positioning in the Field


Auscultation of breath sounds for symmetry (best assessed in each axilla)

Absence of breath sounds over the stomach

Observation of tube fogging and clearing with ventilation

Observation of proper chest rise with ventilation

Proper color change on colorimetric CO2 detector

Prompt filling of an esophageal detector device (bulb or syringe type)


Blind nasotracheal intubation, while useful in a cooperative, spontaneously breathing patient, is a more complicated procedure with a number of inherent drawbacks and will not be discussed.

Tactile or digital intubation is a blind digital procedure to guide the ETT into the trachea. Since the technique involves placing fingers in the patient's mouth, it can be recommended only for deeply unconscious patients. No neck positioning is required, though stabilization of the cervical spine is still important for trauma victims.

An appropriately sized ETT is chosen and a malleable stylet is placed in the tube with a distal, anterior "hockey stick" bend. Following adequate patient preoxygenation, the rescuer places the index and middle fingers of his or her left hand into the patient's mouth on the right side and slides the fingers along the tongue until the epiglottis is palpated in the midline. The endotracheal tube is then passed along the left side of the open mouth, using the medial aspect of the middle finger and the palmar surface of the index finger to guide the tube toward the epiglottis. The tube is then placed against the epiglottis anteriorly with the middle and index fingers posteriorly. The fingers provide firm, anterior pressure that is needed to guide the tube through the glottis.

Care should be taken not to force the tube initially too far into the larynx, as the anterior bend of the stylet may bring the tip of the tube into contact with the anterior wall of the trachea and block further passage. It is better to place the tube through the cords, withdraw the stylet, and then advance the tube to the appropriate depth as is done for orotracheal intubation. Tube position verification must be carefully checked (see table 1).

Surgical Airways

The indication for a surgical airway is, quite simply, the need to secure a definitive airway when the patient cannot be intubated using a less invasive technique. Fortunately, this situation is very rare. Brisk hemorrhage of the upper airway may make direct laryngoscopy and oral intubation impossible. Likewise, laryngeal edema or fracture may obstruct the glottic opening, making ventilation or intubation from above impossible.

Surgical airway techniques include percutaneous needle cricothyrostomy, standard surgical cricothyrotomy, and tracheostomy. Emergency tracheostomy is an extremely difficult technique, fraught with complications, and should be avoided in field settings unless an experienced surgeon is doing the procedure. It is beyond the scope of this article.

Percutaneous needle cricothyrostomy. Percutaneous needle cricothyrostomy (PNC) involves placing a large-bore, catheter-over-needle device (such as a standard, 12-, or 14-gauge intravenous catheter or a device specifically designed for this purpose, such as the Emergency Transtracheal Airway Catheter (Cook Critical Care, Bloomington, Indiana), through the cricothyroid membrane (CTM). This is the preferred surgical airway technique for children younger than 12 (4). Younger children lack a large enough CTM to allow for surgical cricothyrotomy. Cricothyrostomy, if combined with an appropriate oxygen delivery device, allows adequate oxygenation for most patients as they are being transported to a facility capable of establishing a more definitive airway. Exhalation of carbon dioxide, however, may be incomplete with this technique, and respiratory acidosis may develop. The patient usually has about 30 to 45 minutes before acidosis becomes critical (3).

The procedure. The rescuer identifies the CTM by palpating downward from the notch of the thyroid cartilage and uses the dominant hand to place the needle (figure 3: not shown). If time and conditions permit, the skin over the CTM should be prepared with povidone-iodine (see "Sideline Airway Access: Emergency Cricothyrotomy," April 2000, page 113). Once the trachea is entered, aspiration on the syringe should yield free flow of air. The needle is then angled more acutely in a caudal direction 45° above horizontal, and the catheter is advanced over the needle into the trachea. The needle is then removed.

Oxygen delivery. The catheter is attached to an appropriate oxygen delivery device. Prior planning is critical because options are limited. The best device is a jet ventilation apparatus that is capable of delivering oxygen at up to 50 psi when triggered. Use of such a device requires an oxygen tank and monitoring to prevent a too-rapid depletion of the oxygen. Adequate oxygenation can be achieved by triggering the device for 1 second, then pausing for 3 seconds to allow for some exhalation. The chest should be watched for adequate rise and fall.

An alternative to buying a formal jet ventilator is to use high-pressure oxygen extension tubing with a three-way stopcock attached. With all ports of the stopcock open, oxygen is insufflated by occluding the side port with the rescuer's thumb for approximately 1 second. The thumb is then removed from the side port for about 3 seconds to allow for exhalation. This setup will, however, rapidly deplete an oxygen tank. A final solution involves use of a resuscitation bag attached to an oxygen source.

However, to oxygenate adequately and ventilate an apneic adult with a resuscitation bag, a catheter of at least 4 mm internal diameter must be used (5). The 15-mm adapter from a 3.0 ETT can be attached to the catheter hub to allow use of the resuscitation bag. Once the catheter is placed and oxygenation begun, the catheter must be held firmly at the skin to prevent inadvertent displacement. If displacement occurs, insufflation of oxygen into the subcutaneous tissues can be disastrous, making further attempts at securing an airway much more difficult.

Contraindications. PNC is contraindicated when a complete upper-airway obstruction cannot be relieved, because insufflation of oxygen without exhalation will ultimately result in severe barotrauma. It may be possible, in an extreme circumstance, to place a second catheter through the CTM (alongside the first catheter) to allow for egress of gases.

Surgical cricothyrotomy. In patients older than 12 who have a CTM large enough for placement of a ventilation tube, a cricothyrotomy is the surgical airway of choice, provided the rescuer is adept at the technique. This technique's advantage lies in the ability to place a larger, often cuffed, tube into the airway, thereby facilitating adequate oxygenation and ventilation and minimizing the risk of aspiration.

The technique. The rescuer locates the CTM and, if possible, prepares the skin. The rescuer stabilizes the larynx with the thumb and long finger of his or her nondominant hand and palpates the CTM with the index finger. A #10-blade scalpel is used to make a longitudinal incision 2 to 2.5 cm along the midline directly over and down to the CTM. The tissues overlying the CTM are typically quite thin, and such an incision reduces the risk of cutting large vessels on either side of the CTM.

The CTM is wider in the transverse plane than it is in the longitudinal plane. Therefore, with the skin edges retracted, a transverse incision is made across the CTM and the blade is left in the incision (ie, inside the trachea). It is critical that once this point is reached, an instrument be kept in the tracheal incision to avoid losing the proper tract until the airway is successfully placed.

A pair of hemostats are placed into the airway with the tips on either side of the scalpel blade, and the scalpel is removed. The hemostats are gently spread in the transverse and longitudinal directions, enlarging the hole. A tracheal hook can be used to grasp and elevate the cricothyroid cartilage to allow the rescuer more control during airway placement.

An appropriate ETT (<6.0 mm tube in an adult) or tracheostomy tube is placed into the opened hole and the hemostats or trachea hook removed. If a cuffed tube is used, the cuff is inflated and the patient is ventilated using a bag-valve device. The tube is held securely in place until its position is checked (see table 1) and then is secured with a cloth tie. Care should be taken because right mainstem intubation easily occurs in cricothyrotomy with a standard ETT.

Alternative techniques. The rescuer who may not be as comfortable with surgical techniques may use the Melker Cricothyrotomy set (Cook Critical Care, Bloomington, Indiana). This kit allows placement of an uncuffed airway through the CTM via a Seldinger technique. The initial steps of the technique are similar to that for PNC, but the kit has a guidewire to aid making a stab incision. A special airway catheter with dilator is then passed along the guidewire into the trachea (figure 4). The only significant disadvantage to this device is that it uses an uncuffed tube, which does not protect against aspiration.

[Figure 4]

Other cricothyrotomy kits designed for placement by relatively inexperienced personnel must be evaluated carefully because the risks with devices, such as cricotomes, can be significant.

Surgical airway complications. Complications (table 2) can be minimized if the rescuer has had some training in the techniques (eg, in cadaver labs and/or working with specially designed procedure mannequins). Often, a regional sales representative for a device can be contacted for mannequin training.


TABLE 2. Most Common Complications of Surgical Airway Techniques


Hemorrhage

Laceration or other damage of surrounding structures (eg, neurovascular structures, thyroid gland, vocal cords, esophagus)

Subcutaneous emphysema

False passage into surrounding tissues

Hypoxia after prolonged or failed attempts

Aspiration

Infection

Tracheal stenosis or cricothyroid cartilage damage


Anticipating Emergencies

Airway emergencies can require more advanced treatment methods for the seriously injured athlete. Physicians can prepare for such emergencies by ensuring that appropriate equipment is available and functional, and by being familiar with advanced and surgical techniques. Training for advanced methods can be obtained from courses and teaching videos (eg, The National Emergency Airway Management Course, phone: 800-458-4779), manufacturers of kits, and anesthesiologists. Essential equipment and training can mean the difference between life and death for the stricken athlete.

References

  1. Grande CM: Appropriate techniques for airway management of emergency patients with suspected spinal cord injury. Anesth Analg 1988;67(7):714-715
  2. Chameides L, Hazinski MF (eds): Pediatric Advanced Life Support. Dallas, American Heart Association, 1997, pp 1.1-11.11
  3. Cummins RO (ed): Advanced Cardiac Life Support. Dallas, American Heart Association, 1994, pp 1.1-16.10
  4. Advanced Trauma Life Support Program for Doctors. Chicago, American College of Surgeons, 1997, pp 1-504
  5. Yealy DM, Steward RD, Kaplan RM: Myths and pitfalls in emergency translaryngeal ventilation: correcting misimpressions. Ann Emerg Med 1988;17(7):690-692

Dr Norris is an associate professor of surgery and emergency medicine and chief of the division of emergency medicine at Stanford University Medical Center in Stanford, California. Dr Peterson is a resident physician in the Stanford/Kaiser Emergency Medicine Residency Program in Stanford, California. Address correspondence to Robert L. Norris, MD, 701 Welch Rd, Suite 3, Palo Alto, CA 94304; e-mail to [email protected].


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