24 THORACIC TRAUMA

INTRODUCTION

Thoracic injuries account for much of the immediate life-threatening trauma encountered in the field or in the hospital setting. These injuries usually require rapid and skilled responses and considerable clinical judgment by nurses. Chest injuries and their effects on the patient are the subject of this chapter. The purpose is to educate the nurse about the most common injuries sustained in the thoracic region and about complications of these injuries throughout the phases of trauma care. This chapter describes specific injuries of the heart, lungs, lower airways, major vascular structures, and bony thorax itself and explains physiologic alterations associated with trauma that may affect the respiratory system.

The discussion of each injury includes a description of the injury’s symptoms, pathophysiology, diagnosis, and management, but the patient’s pain and fear of death and treatment must be considered with every injury. Each intervention begins with the nurse explaining procedures, treating pain and fear, and supporting the patient and family through medical and nursing therapies. These statements are not written over and over again but they are implied with each injury and complication. There is time to assist in treating the pneumothorax and to change the patient’s uncomfortable position and to explain what having a chest tube will be like. Each of these three therapeutic actions is done in the priority order indicated by an assessment of the individual patient.

EPIDEMIOLOGY OF THORACIC INJURIES

A commonly cited statistic suggests that thoracic injuries are responsible for approximately 20% percent of all traumarelated deaths.¹ This citation, however, is not only dated but relied heavily on inference and extrapolation and not use of rigorous scientific methods for data collection. But, as the authors acknowledged, “Few statistics are available in the United States on chest trauma itself’.”¹ Today, published statistics on thoracic trauma remain sparse. For the 10-year period from 1996-2005, the trauma registry at the R Adams Cowley Shock Trauma Center (STC) in Baltimore, Maryland, indicates that approximately 5750 patients per annum arrived in the trauma resuscitation unit.² On average, 28% of admissions were classified as having an injury to the thorax. Of those patients admitted with a thoracic injury, 54% may be classified as a serious thoracic injury. With the use of the Abbreviated Injury Scale,³ “serious thoracic injury” may be defined as a score of >2 (on a scale of 1 to 6, where 1 is considered minor and 6 virtually nonsurvivable). Patients who die and have a serious thoracic injury (as defined above), although potentially other serious injuries may be present, make up 56% of all deaths of all admissions to the STC.²

The epidemic of societal violence has changed the patterns of chest injuries that dominated previous decades. A significant number of violent interactions involving shootings or stabbings result in penetrating chest trauma.⁴ Likewise, growth in the elderly segment of the population has an impact on the changing pattern of thoracic injury. Today, patients older than 65 years of age seen at the STC have a 30% chance of having thoracic trauma (mild, moderate, or severe).²

Sophisticated prehospital care and expeditious transportation to a definitive trauma care site have improved the detection, treatment, and outcome of injuries that were previously found only on postmortem examinations. Advancements in the management of thoracic trauma have occurred primarily because military campaigns, motor vehicle crashes, and societal violence have prompted clinicians to modify their practice, thereby improving response times, diagnosing more quickly, and initiating treatment earlier. Research, practice, and technology have progressed simultaneously. Type, severity, and number of various thoracic injuries will continue to evolve as long as clinicians, manufacturers, and lawmakers remain responsive to data collected by members of the health care community. Motor vehicle design modification, such as automated driver and passenger restraint systems; new laws to include zero blood alcohol tolerance for young drivers and previous offenders; and clinical interventions previously reserved for the hospital being executed in the field or ambulance are all changes that have been made with the hope of improving outcomes from trauma.

T HORACIC ASSESSMENT IN TRAUMA

The assessment of patients with thoracic injury is based, as is any type of trauma examination, on a series of diagnostic clues obtained from directed data collection. Initially the data are used to form a diagnostic set known as the index of suspicion. In other words, given the specific details of the incident and the initial, rapid assessment, a list of injuries most likely to be present is identified.⁵

HEALTH HISTORY

In addition to the injury history, the personal health history gives insight into the individual’s unique response to shock and thoracic injury. Whether the historian is the patient or a family member, the nurse attempts to determine the patient’s previous respiratory, cardiac, and vascular status. Previous cardiopulmonary problems are uncovered through the usual review-of-systems approach and selective and directed questioning. The injured person is frequently young and has an unremarkable cardiopulmonary or vascular history. Nevertheless, questions should be asked specifically about the presence of persistent upper or lower respiratory infections, asthma, or chronic sinus problems; smoking, alcohol, and drug abuse history should also be investigated. Any of these problems may affect the patient’s tolerance of nasal or oral endotracheal tubes or the response to mechanical ventilation. It is particularly important to ask whether there have been any previous trauma incidents or injuries.

Although it is not always possible, every endeavor is made to extract a recent health history from the patient. Chief complaints, which frequently include chest pain and difficulty with breathing, should be noted. Some patients may clearly describe or point to a specific location of pain. If a history cannot be elicited from the patient because of altered level of consciousness, intubation, or distracting injuries, emergency medical personnel and, less commonly, non-health care witnesses such as friends, bystanders, or police may be consulted for ascertaining key information. This includes information about the mechanism of injury (e.g., motor vehicle crash; size and type of weapon; number of times weapon was used; height of fall), extrication time, and fatalities at the scene. Further information to obtain about the patient includes length of time from moment of trauma to arrival in the resuscitation area, treatment administered by prehospital providers (e.g., amount of resuscitation fluid given), and patient response to interventions (e.g., trends in vital signs).

THORACIC ANATOMY

Correlation of underlying anatomy and surface landmarks is imperative in the trauma examination. The examiner must be able to identify key structures in the true thorax, the cervicothoracic inlet, and the boundaries of the thoracoabdominal cavity. Key structures include the trachea, carotid arteries, carina, lung fields, diaphragm, cardiac borders, aorta subclavian arteries, and pulmonary artery (Table 24-1). External landmarks and knowledge of the relationship with internal structures assist in identifying injuries (Figures 24-1 through 24-5).

TABLE 24-1 Thoracic Surface Anatomy

Structure	Landmarks
Aorta
Root	Angle of Louis, midsternal line
Arch	First rib, sternal border
Pulmonary artery	Within and below aortic arch
Subclavian artery	First rib, clavicle
Cardiac borders
Apex	Fifth left ICS, midclavicular line
Base	Second left ICS, substernal
Carina	Angle of Louis
Diaphragm	Right dome superior to left
Full inspiration	Tenth-eleventh rib posteriorly, sixth-eighth rib anteriorly
Full expiration	Tenth thoracic vertebra posteriorly, fourth-fifth rib anteriorly

ICS, Intercostal space.

FIGURE 24-1 Anatomy of the thorax and its contents.

(From Shires GT: Care of the trauma patient, New York, 1985, McGraw-Hill.)

FIGURE 24-2 Spinal column and thoracic structures. The cervical, thoracic, and lumbar vertebrae correspond with specific anatomic structures. These landmarks are helpful in determining different thoracic levels. Palpation of the spinous processes proves helpful in ascertaining the level of the wound and the structures that may be involved.

(From Naclerio EA: Chest injuries, Orlando, 1971, Grune & Stratton.)

FIGURE 24-3 Cervicothoracic region. The root of the neck is actually the cervicothoracic region, which forms a boundary between the neck and the thorax. It is occupied by a number of vital structures that enter or leave the thoracic cavity. As shown, the apex of the lung rises above the level of the anterior part of the first rib. The subclavian artery lateral to the subclavian vein is separated from the lung by the membranous cervical diaphragm and the pleura.

(From Naclerio EA: Chest injuries, Orlando, 1971, Grune & Stratton.)

FIGURE 24-4 Correlation of surface to underlying thoracic anatomy. Anterior view, Note the relationship of the heart, great vessels, and lungs to bony thorax. Posterior and right lateral views, Major and minor interlobar fissures. Left lateral view, Note single interlobar fissure.

FIGURE 24-5 The thoracoabdominal region in thoracic assessment. Arrows indicate the variation in diaphragm and lung position during respiration.

PHYSICAL EXAMINATION

Primary Survey

The primary survey identifies life-threatening conditions. Management of any threat to life begins immediately, before progressing to the rest of the primary survey. Traumatic injuries to the chest can kill swiftly. On arrival the patient’s airway is assessed, predominantly for obstruction. Noisy breathing or stridor indicates obstructed breathing and must be corrected or the natural airway bypassed with placement of an artificial airway. Independent of identified chest trauma, a Glasgow Coma Scale score of 8 or less is often seen as an indication for intubation for airway protection. Similarly, loss of gag, cough, or ability to protect the airway will warrant intubation. With the patient’s chest completely exposed, the respiratory pattern is assessed, including the rate, depth, and chest movement, namely, noting equality of movement and possible presence of paradoxic motion of the chest wall (flail segment). Adequate ventilation must be established. Cyanosis is often a late finding in the trauma patient; thus, the absence of cyanosis does not necessarily equate to the absence of hypoxemia.

Ensuring adequate circulation is the next priority. Although blood pressure (BP) and pulse are noted, neither is a definitive sign of shock. The heart rate may be elevated in the trauma patient as a result of pain and anxiety, even in the absence of significant injury. Conversely, patients prescribed β-blockers may have a relatively slower heart rate than expected. Low BP is a late marker of shock ⁶ and not recommended as a sole indicator of poor tissue perfusion.^4,⁶ This is particularly true in young patients who have the ability to vasoconstrict and maintain a relatively normal BP despite significant intravascular volume loss. Warm extremities, brisk capillary refill time, normal mentation, and adequate urine output indicate an intact cardiovascular system providing adequate tissue perfusion. The neck veins are assessed for distention. Although jugular venous distention (JVD) may accompany injuries such as tension pneumothorax and cardiac tamponade, these conditions may be present even in the absence of JVD, which may not be evident because of hypovolemia.

During the initial survey, the presence or suspected presence of a pneumothorax or hemothorax is treated with a thoracostomy tube. A tension pneumothorax, considered a serious and often life-threatening form of pneumothorax, requires immediate decompression, which may be initially achieved by inserting a large-bore needle (e.g., 14-gauge) into the second intercostal space over the rib margin in the midclavicular line of the affected side. The tension pneumothorax is thus converted to a pneumothorax, and treatment with a thoracostomy tube may be pursued.

Finally, the patient’s axillas are assessed and the patient is turned and the back inspected, and the number and location of penetrating wounds or blunt injuries are noted. To turn the patient who had sustained blunt trauma requires “log-rolling,” although this technique is not always an imperative in penetrating injuries. Clinical judgment is the best guide as to whether log-rolling is indicated in the latter group.⁷

PHYSIOLOGIC APPROACH

Clinical monitoring of BP, cardiac rate and rhythm, respirations, urine output, and ABGs is considered a standard part of patient management after thoracic injury. However, it is recognized that BP is frequently unaffected until a 30% loss in blood volume has been sustained.⁴ Although invasive monitoring of central venous pressure may be helpful in evaluating intravascular volume, it is not routinely initiated during early fluid replacement and management of significant thoracic injuries. The time required to insert a central venous catheter cannot be afforded during initial moments of resuscitation; therefore, large-bore (14-gauge) peripheral intravenous catheters are preferable for volume repletion. If the patient has limited intravenous access, a central venous line can be placed.

Definitive management in the operative and critical care phases requires a practical yet comprehensive approach to systemic cardiopulmonary monitoring. The nurse must be familiar with an extensive array of cardiopulmonary variables and accompanying monitoring technology to be able to assess patients with thoracic trauma. The patient-ventilator system is monitored as a unit and is an important source of data about the patient’s pulmonary status.

Arterial and pulmonary artery catheters provide information useful for assessing patients with extensive injuries and related complications. These hemodynamic parameters can also aid in determining the effect of therapies such as inotropes, fluids, and positive end-expiratory pressure (PEEP). When indicated, mixed venous oxygen tension and saturation monitoring may be helpful tools in determining circulatory sufficiency and global tissue oxygen consumption. In particular, geriatric patients, including the apparently clinically stable group, with multiple fractures, head injury, acidosis, initial systolic BP <150 mm Hg, or who were pedestrians struck by a motor vehicle may benefit from early invasive monitoring coupled with judicious use of vasoactive drugs.^8,⁹ Table 24-2 is a summary of physiologic parameters that may be obtained to monitor the patient with thoracic trauma.

TABLE 24-2 Common Cardiopulmonary Parameters in Thoracic Assessment

NONINVASIVE MONITORING

The oxygenation status of the patient can be assessed by using noninvasive monitoring with pulse oximeters and transcutaneous, conjunctival, or tissue oxygen tension monitors. Oximetry is the determination of the oxygen-hemoglobin saturation of the blood and may be measured with an appropriate sensor that detects the pulsatile blood flow through some translucent part of the body (e.g., fingers, ear lobes, nasal septum, forehead). Pulse oximetry (SpO₂) is well accepted as a convenient, portable, noninvasive, and cost-effective indicator of arterial oxygen saturation (SaO₂). Pulse oximetry estimates the fractional hemoglobin saturation by determining the maximal light absorbance of the different hemoglobin species. Practical application of this technology aids both the detection of hypoxemia (SaO₂ <90%) and hyperoxemia (SaO₂ >98% in the presence of supplemental oxygen), allowing for appropriate titration of inspired oxygen concentration and other mechanical ventilator settings. SpO₂ measures are up to 4% higher than SaO₂ when at 90%, assuming that the only hemoglobin species present are reduced hemoglobin and oxyhemoglobin. The accuracy of SpO₂ measures may be reduced in the presence of movement, significant amounts of carboxyhemoglobin or methemoglobin, dark skin pigmentation, hypothermia, and hypovolemia, although advancements in technology continue to negate the impact of these variables. Anemia, once considered to affect accuracy, may have only a minor impact on the precision of measurements with the pulse oximeter.¹⁰ Because pulse oximetry depends on pulse transmission, intense peripheral vasoconstriction may also be associated with lost or inaccurate readings. Generally, when the SaO₂ is greater than 90%, the accuracy of the SpO₂ increases substantially. An SpO₂ of less than 92% serves as a trigger to consider additional tests to confirm the oxygenation status of the patient.^10,¹¹

Noninvasive assessment of carbon dioxide (CO₂) is complex, especially in critically ill patients with significant ventilation-perfusion (V/Q) abnormalities, increased physiologic dead space, and hemodynamic instability. When these confounding factors are stable, changes in end-tidal CO₂ (ETCO₂) can be assumed to reflect changes in alveolar ventilation and arterial CO₂ tension (PaCO₂). ETCO₂ monitoring by mass spectrometry or an infrared analyzer correlates reasonably well with PaCO₂ and is used in a variety of environments, including prehospital, emergency department (ED), and operating, recovery, and critical care areas.¹² In relatively healthy patients, the relationship between PaCO₂ and ETCO₂ is close (less than 5 mm Hg difference), with the exhaled CO₂ (ETCO₂) commonly lower than the PaCO₂. For example, a PaCO₂ of 40 mm Hg might correlate with an ETCO₂ of 36 mm Hg.¹² As with other forms of monitoring, analysis of a trend over time rather than an individual value is most useful because there may be considerable breath-to-breath variability. Currently, there is some interest in the use of ETCO₂ to identify patients requiring more aggressive resuscitation during emergency trauma surgery¹³ and as a predictor of death in patients undergoing emergency trauma surgery.¹⁴

Sublingual capnometry may be destined to play a role as a noninvasive indicator of the depth of shock and adequacy of resuscitation. Sublingual capnometers consist of three components: a disposable CO₂ sensor (placed under the tongue, equilibrates with the corresponding CO₂ level in the superficial mucosa), a fiberoptic cable, and, a blood gas analyzer. Within 5 minutes of connecting the components, a sublingual CO₂ measurement is attained. Such values may be useful as end points of resuscitation.¹⁵

INTEGRATING OTHER DIAGNOSTIC DATA

Other diagnostic data used to complete a total thoracic trauma assessment include laboratory, radiographic, ultrasonographic, and magnetic resonance imaging (MRI) data. Essential laboratory data include ABGs with base deficit measurement, complete blood cell count, including hematocrit and hemoglobin, clotting studies, serum electrolytes, osmolality, and lactate. A recent sputum or transtracheal aspirate culture may also be indicated. A drug and alcohol screen may also prove useful.

Thoracic evaluation commonly includes a CXR to visualize any significant bony, vascular, or pulmonary injuries (Figure 24-6, A and B). The appropriate angle of the film (supine, upright, or lateral) is used for best exposure of specific structures yet must consider any restrictions in positioning the patient. Often, as a result of hemodynamic instability or other suspected injuries (e.g., spinal column fracture), the CXR is a portable, supine, anteroposterior (AP) view. For penetrating injuries, a radiopaque marker is placed at suspected entrance and exit sites.¹⁶

FIGURE 24-6 Normal AP (a) and lateral (b) films of the chest.

One of the most valuable assessment tools in thoracic trauma is a clear, high-quality upright CXR. The patient should face the radiograph beam at a 110-degree angle to avoid unnecessary distortion of underlying structures on the CXR. A true upright film allows better visualization of vascular injuries within the chest and some estimation of the amount of blood or fluid in the chest cavity. Cardiac and aortic borders are also less distorted. Before an upright film is obtained, spine injury must be ruled out.

Digital total-body radiographic scanning (StatScan) may aid in the diagnosis of thoracic injury. StatScan is a comprehensive diagnostic total body x-ray examination that can be completed in less than 5 minutes and at a greatly reduced overall radiation dose to medical staff and patients. Initial images are available in less than 10 seconds. The quality of the x-ray film is reasonable although generally limited to one view (AP). StatScan plays a role in quickly and simultaneously identifying abnormalities of the thorax and the rest of the body ¹⁷ (Figure 24-7).

FIGURE 24-7 Image produced by the StatScan total body radiograph machine. The total body radiograph of this young man identified two bullets. One is in the region of the left chest, and the other is in the right lower extremity associated with a fractured fibula.

Overall, the use of plain radiographs is decreasing in the acute trauma setting in part because of the increased use of CT scanning. The CT scan is more sensitive in detecting hemothorax, pneumothorax, and pulmonary contusion than is the CXR.¹⁸ Evaluation of underlying lung, cardiac, and mediastinal structures is also enhanced by the use of CT scans. However, a simple and rapid assessment of blunt trauma patients with CXR and abdominal ultrasonography may alert the clinician to significant injury.¹⁹ Aortography remains the standard for evaluating aortic branch vessel injury,^20,²¹ although a contrast-enhanced CT may have a sensitivity and negative predictive value equivalent to that of aortography for assessment of just the aorta.^22,²³ An abnormality of a branching vessel would be an indication to proceed with aortography. Assessment of penetrating trauma may also undergo a decline in use of angiography and other invasive tests as the role of contrast-enhanced CT is expanded.²⁴ As CT technology advances, the potential applications are increasing.²⁵

Three-dimensional (3-D) images of the thorax can be obtained after multidetector row CT scanning. Certain structures may be deleted on the radiograph to allow better visualization of other structures. 3-D imaging plays a role in clarifying complex vascular and nonvascular anatomy. Further technical developments will help solidify the role of two- and three-dimensional reconstructions in the management of thoracic trauma ²⁶ (Figure 24-8).

FIGURE 24-8 3-D view of right-sided rib fractures. Multiple rib fractures are identified on the right lateral view of a 3-D image.

Ultrasonography of the thorax is a relatively new diagnostic tool. Although the surgeon-performed focused assessment by sonography for trauma (FAST) examination has become a standard part of the abdominal assessment for hemorrhage, ultrasonography of the thorax awaits mainstream acceptance and use. The exception, however, is sonography for rapid diagnosis of traumatic pericardial fluid collections.²⁷ Recently, use of sonography for the diagnosis of pneumothorax has gained more interest.^28,²⁹ Although posttraumatic occult pneumothoraces may be more likely to be identified by ultrasonography than by a plain CXR,³⁰ the accuracy of ultrasonography continues to be limited by the expertise of the user.

The use of MRI in the acutely ill patient with thoracic trauma is limited by the incompatibility of many metallic implants and life support devices with the magnetic field. Coupled with limited visualization and the potential for rapid hemodynamic deterioration while the patient is in the scanner, MRI is typically not a desirable diagnostic strategy for this group of patients. The use of MRI may be considered an adjunct diagnostic tool in appropriately selected patients, although it will probably have an increasing role as MRI-compatible physiologic support and monitoring devices become increasingly available.²⁵

REASSESSMENT AND EARLY THORACOTOMY

Repeated thoracic assessment is the key to determining missed or progressive injuries. Injury to the thorax requiring intervention may be broadly split into three categories: those requiring observation, tube thoracostomy (chest tube), and formal thoracotomy. The majority (85%) of thoracic trauma cases requiring intervention are managed with tube thoracostomy (chest tube), pain control, pulmonary toilet, and observation.³¹

Should the patient’s condition deteriorate or result in cardiac arrest, immediate exploratory thoracotomy may be performed. Indications for the procedure have been the subject of considerable controversy. Resuscitative ED thoracotomy may be indicated for the following:

1. Penetrating thoracic trauma with a systolic BP <40 mm Hg or prehospital signs of life

2. Penetrating nonthoracic trauma, noncranial trauma with a systolic BP <40 mm Hg and signs of life in the resuscitation area

3. Cardiac arrest after blunt chest or abdominal trauma after arrival in the ED with an obtainable BP ¹⁶

Successful outcomes after ED thoracotomy are often related to reversible conditions such as cardiac tamponade, controllable intrathoracic bleeding, elimination of massive air embolism, or bronchopleural fistula. Thoracotomy also permits open cardiac massage and access to the descending aorta to facilitate temporary clamping to redistribute limited blood flow to the myocardium and brain while stifling any subdiaphragmatic bleeding.³² Historically, patients were more likely to survive an ED thoracotomy if they had sustained a penetrating injury (5% to 8% survival) than a blunt trauma (<2%) or were in extremis after extrathoracic injuries (<1%).³³ Recently, a small European study suggested that patients with blunt trunk trauma and cardiac arrest after hemorrhagic shock may benefit from ED thoracotomy and open massage with a similar probability of survival as shown for patients with penetrating injury. However, the success of the intervention was contingent on early thoracotomy after closed chest resuscitation of less than 20 minutes by trained professionals. On average, the survivors of open chest cardiac massage had undergone 13 minutes of closed chest cardiopulmonary resuscitation before the thoracotomy.³⁴

Thoracoscopy may be useful in limited emergency situations. This procedure may be used on stable patients with penetrating chest injuries, for diagnostic evaluation, or to control bleeding and remove blood clots.³⁵

INJURIES

AIRWAY OBSTRUCTION

Airway assessment and management is the first imperative in the care of any trauma patient. Airway obstruction occurs frequently in trauma patients from primary injury to the airway (e.g., injuries to the pharynx, larynx, trachea) or as the result of some other injury. The source of an obstruction and the therapeutic approach are slightly different in the patient with a natural airway versus one with an artificial airway already in place. However, the principles of basic and advanced life support are fundamental in management of all obstructions.

The Patient With a Natural Airway

The most common sources of obstruction are the tongue and foreign bodies such as teeth, blood clots, and bone fragments. The unconscious patient in shock or one with central nervous system, maxillofacial, or neck injuries is at particularly high risk. Loss of protective airway reflexes including the cough and gag also increase risk of aspiration and loss of airway patency.

Assessment begins with rapid determination of airway patency by evaluating whether there is air passage through the upper respiratory tract into and out of the lungs. This evaluation is followed by observation of the rate and pattern of ventilation. Air movement through the airway, if any, may be noisy, indicating presence of a partial obstruction. Respiratory distress may or may not be immediately evident. Continuous pulse oximetry monitoring can detect reductions in the oxygen saturation of hemoglobin, and ABGs are measured as the most certain method of assessing oxygenation and ventilation.

Airway obstruction must be corrected immediately or the natural airway bypassed. Initially the airway is opened by a chin-lift or jaw-thrust maneuver, and the oropharynx is cleared by suction. Any obvious foreign material is removed manually. Each step is performed with great care to maintain immobility of the cervical spine until injury to the spine has been ruled out. Initial manual airway maneuvers may be inadequate or only temporary solutions; therefore, more definitive airway control is often required.

The simplest adjuncts are placement of an oral or nasal airway. Both are generally for short-term use and have restricted use in patients with facial trauma such as nasal fractures, cribriform plate fractures, or oropharyngeal injury. The oropharyngeal (or Guedel) airway is reserved for the unconscious/unresponsive patient because this device may otherwise cause gagging and vomiting. The nasopharyngeal airway (or Trumpet) may be tolerated better by the patient with a higher level of consciousness. However, this device is contraindicated with basilar skull fractures and cribriform plate defects for fear of penetration into the cranial cavity.

When positioning does not relieve the obstruction, endotracheal intubation is the management technique of choice for most types of trauma. Alternatives to conventional intubation include use of the Laryngeal Mask Airway (LMA) (Laryngeal Mask Company) or the esophageal Combitube (Sheridian Catheter, Argyle, NY). These devices are blindly inserted into the pharynx and on inflation of their seal allow for ventilation of the lungs. The Combitube is relatively easy to insert, even after only brief training. The LMA has a less well defined role in the trauma population and is generally not tolerated if the gag reflex is present.³⁶

In general, oral endotracheal intubation with rapidsequence induction using a short-acting sedative and paralytic agent is the gold standard for securing an airway. This may be done safely after cervical spine injury has been ruled out or even in cases of unknown cervical spine status provided the neck does not require aggressive manipulation to visualize the vocal cords. Cricoid pressure is applied routinely during the procedure. The rationale is that the trauma patient is likely to have a full stomach and is therefore at risk for aspiration of gastric contents. Cricoid pressure is maintained until the tube is inserted, cuff inflated, and bilateral chest sounds auscultated.

Although oral-tracheal intubation constitutes the preferred airway management, there are several caveats. If the patient is unstable but breathing and the urgency of airway management does not allow preliminary cervical spine clearance, blind nasotracheal intubation may be attempted. Conversely, an oral-tracheal route is used if the patient is apneic and the cervical spine is immobilized manually in a neutral position. Last, fiberoptic laryngoscopy and bronchoscopy may be useful to facilitate difficult intubations in stable patients, particularly in those individuals with maxillofacial or cervical spine trauma and in patients with short necks.³⁷ Scopes may be less practical in the emergency or urgent situation.

If the patient cannot be intubated successfully, emergency cricothyroidotomy is recommended. In the event a surgical airway is required, a cricothyroidotomy is preferred over a tracheostomy. Comparatively, a cricothyroidotomy is less bloody, quicker, and considered easier to perform.³⁷ There are two cricothyroidotomy procedures currently in use. The first is a surgical technique in which a transverse incision is made through the skin and the cricothyroid membrane, located below the thyroid prominence of the neck. Usually, a No. 6 endotracheal tube is inserted into the exposed airway (Figure 24-9). A second approach, needle cricothyroidotomy or percutaneous transtracheal ventilation, is initiated by insertion of a 14-gauge needle into the trachea at the cricothyroid membrane below the level of obstruction. Pressurized oxygen is insufflated intermittently through the needle into the trachea. The limitation of the needle cricothyroidotomy is that ventilation is usually impaired despite sufficient oxygenation. The choice of method depends on the injury, available equipment, and capability of the resuscitating health professional.

FIGURE 24-9 Cricothyroidotomy technique.

(From Zuidema GD, Rutherford RB, Ballinger WF: Management of trauma, 4th ed, Philadelphia, 1985, W. B. Saunders.)

The choice of appropriate airway requires consideration not only of available equipment and personnel but also factors specific to the patient, the injury, and short- and long-term management plans. For example, early intubation may be indicated not only for airway management but also for intraoperative or critical care management of patients with thoracic injuries. Table 24-3 summarizes the advantages of different artificial airways, their restrictions, and their potential complications.

TABLE 24-3 Airway Adjuncts in Trauma

Oropharyngeal Airway
Indications	Unconscious patients without gag reflex; short-term use
Advantages	Holds tongue away from posterior pharynx
Restrictions	Oropharyngeal injuries
Complications	Intraoral injury; induction of vomiting and aspiration; increased obstruction if positioned incorrectly by pushing the tongue back into pharynx
Nasopharyngeal Airway
Indications	Semicomatose or arousable patients with decreased control of upper airway; prevention of tissue trauma during frequent nasotracheal suctioning
Advantages	Better tolerated in awake patients than oral airway; easily secured
Restrictions	Maxillofacial trauma such as nasal, nasoethmoid fractures
Complications	Nasopharyngeal injury; nasal bleeding
Esophageal Obturator Airway, Combitube, Pharynotracheal Lumen Airway, Laryngeal Mask Airway
Indications	When unable to successfully place endotracheal tube
Advantages	Can be positioned quickly without direct visualization, with minimal manipulation of cervical spine
Restrictions	Cannot be used in awake or semiconscious patients
Complications	Induction of vomiting and aspiration; esophageal tears; postpharyngeal bleeding; unrecognized incorrect placement
Endotracheal Tube
Indications	Preferred method of airway control
Advantages	Stable airway; provides protection from aspiration; permits mechanical ventilation to be used; decreases gastric distention associated with bag-mask ventilation
Restrictions	Used with caution in presence of laryngotracheal injuries (glottis, subglottis, and upper trachea)
Complications	Esophageal intubation leading to hypoxia; right mainstem bronchus intubation; induction of vomiting and aspi- ration; vocal cord injury; pharyngeal injury; tracheal lacerations; conversion of cervical spine injury without neurologic deficit to injury with deficit; dislodged tube
Cricothyroidotomy
Indications	When intubation does not relieve obstruction or trachea cannot be intubated
Advantages	More rapid, greater ease of accessibility, and lower incidence of bleeding than tracheostomy
Restrictions	Children younger than 12 years old; laryngeal injury or inflammation
Complications	Subglottic stenosis; vocal cord injury; aspiration; hemorrhage; tracheal or esophageal laceration; mediastinal emphysema; dislodged tube
Standard Tracheostomy
Indications	When intubution does not relieve obstruction or in significant laryngeal or tracheal trauma; used for prolonged ventilatory support
Advantages	Bypasses upper airway and glottis; stable airway with low resistance to air flow; easily suctioned
Restrictions	Limited use as an emergency procedure because of time requirements and potential for bleeding
Complications	Early or delayed hemorrhage; aspiration; mediastinal emphysema with or without pneumothorax; tracheoesophageal fistula; tracheal stenosis; tracheomalacia; tracheoarterial fistula; dislodged tube

The Patient With an Artificial Airway

In trauma patients with an artificial airway in place (routinely an endotracheal or tracheostomy tube), obstructions or partial obstructions may occur, usually in an insidious and subtle fashion. Obstruction may be caused by thick or dried secretions or blood clots within the lumen of the airway or malposition of the airway. Assessment of airway patency and effectiveness requires continuous evaluation. Signs of airway obstruction include increasing level of agitation, rising airway pressures during mechanical ventilation (peak inspiratory pressure, not plateau pressure), difficulty in advancement of a suction catheter, and decreased SpO₂ or increased ETCO₂. Frequent evacuation of bloody clots or mucus plugs may precede the occlusion of the airway. Humidification is a front-line measure to prevent secretions from drying in the artificial airway and causing obstruction. Inhalation of aerosolized agents aimed at loosening secretions (e.g., a mucolytic agent such as Mucomyst [acetylcysteine solution]) may also be prescribed. Ensuring that any artificial airway is well secured and supported during repositioning of the patient helps maintain appropriate placement of the device.

The optimal timing of converting an artificial airway from endotracheal to tracheostomy is controversial. Historically, a patient requiring an artificial airway for less than 10 days was managed with an endotracheal tube, and if artificial ventilation was still required after 21 days, a tracheostomy was recommended.³⁸ More recently, advantages to earlier tracheostomy have been suggested.^39,⁴⁰ Advantages include shorter duration of ventilation, shorter intensive care unit (ICU) stay, less damage to the mouth and larynx, and facilitation of communication.

General nursing management begins by documentation of airway type and size, patient tolerance, any complications, duration of intubation, and date of tracheostomy. The patient-specific plan of care is based on such factors as a history of any airway problems, difficulty in intubation, and patient behavior, such as attempts at self-extubation or bronchospasm during suctioning. An identical spare tracheostomy tube, and second with an internal diameter 1 mm smaller than the original, and a manual resuscitator bag with face mask should be located at the bedside for rapid management of obstruction or lost airway. Emergency intubation kits that contain all the necessary equipment for rapid intubation and airway management should be strategically located on the unit. Airway hygiene is implemented on the basis of assessment findings. Tracheostomy care is patient specific depending on the newness of the stoma, the type of secretions or peritracheal drainage, and signs of infection. Commonly, the tracheostomy site is cleaned with saline solution and a gauze dressing is placed around the site at least once a shift and as required. A record is maintained of all tube changes, tube size, and any difficulties encountered in tube placement. The need for long-term airway management is apparent in the intermediate care setting, if not before. An alternative mode of communication (e.g., writing, use of a letter or picture board) must be established for the patient unable to verbally express himself or herself because of placement of an artificial airway. A speech-language pathology consultation may be helpful in determining an alternative means of communication. Insertion of a fenestrated or “talking” tracheostomy will help the patient regain the ability to verbally communicate. As soon as the patient and family indicate readiness, a teaching plan is begun that covers long-term and home management of secretions and tracheostomy care. Excellent reviews of nursing care of the patient with an artificial airway are available.^41,⁴²

TRACHEOBRONCHIAL TRAUMA

Description

The tracheobronchial tree may be injured by either blunt or penetrating trauma at any level. Most commonly, injury involves the mainstem bronchi within close proximity to the carina in blunt trauma and the cervical trachea in penetrating trauma (Figure 24-10). Injuries may be complete or incomplete, and total separation of the tracheobronchial tree can occur. However, continuity of the airway may be maintained by the fascia surrounding the trachea and bronchi. Lower airway injuries are of interest to nurses in all phases of trauma care because discovery of injury may occur dramatically during intubation and mechanical ventilation or may occur surprisingly late in the patient’s posttrauma course. Tracheobronchial tears may also be caused by penetrating injury, frequently in association with esophageal, carotid artery, or jugular vein trauma.

FIGURE 24-10 Tracheobronchial ruptures: general localizations based on literature review. Series included are only those that are not dedicated to a specific location. Three percent of blunt injuries occurred in major bronchi not otherwise localized. Seven percent of penetrating injuries occurred in major bronchi not otherwise localized. N = 325 blunt, 190 penetrating.

(From Riley RD, Miller PR, Meredith JW: Injury to the esophagus, trachea, and bronchus. In Moore EE, Feliciano DV, Mattox KL, editors: Trauma, 5th ed, pp 539-552, New York, 2004, McGraw-Hill.)