Cardiac Arrest
Mouth-to-mouth and BVM ventilation may suffice for out-of-hospital care with short transport times or for the initial few minutes of ventilation in cardiac arrest. However, optimal BVM ventilation during CPR is impossible. Mouth-to-mouth and BVM ventilation are adequate and effective in the anesthetized or paralyzed patient with an empty stomach in the absence of chest compression, but they are inadequate for prolonged ventilation in the patient in cardiac arrest.
Proper BVM ventilation is probably harder to master than tracheal intubation, and prolonged attempts during CPR usually only distend the stomach and give the uninitiated a false sense of security. Patients in cardiac arrest should be orotracheally intubated. Most cardiopulmonary arrests are not associated with cervical spine injury. When there is suspicion of cervical injury, the following precautions should be followed.
Potential Cervical Spine Injury
Any patient who has sustained a significant injury has the potential for cervical spine injury. Approximately 1.5 to 3.0% of initial survivors of all types of major trauma seen in emergency departments have significant cervical spine injury. It is interesting to note that this prevalence is not increased in the setting of significant head injury. Falls from heights and motor vehicle crashes are also common causes of spinal instability.
In patients with multiple injuries, the possibility of cervical spine injury warrants caution when considering tracheal intubation involving the use of the laryngoscope. It is prudent to provide adequate oxygenation while limiting neck extension until cervical spine injury is disproved. If the patient is severely hypoxic or apneic, immediate tracheal intubation may be necessary with in-line manual stabilization of the neck (without axial traction) by an assistant. When done cautiously, oral intubation of the unconscious spinal cord injured patient may be as safe as other techniques, including intubation with fiberoptic guidance.
Note that mouth-to-mouth and BVM ventilation frequently require some degree of neck extension to open the airway. A cadaver study demonstrated increased neck motion with BVM ventilation when compared to various intubation techniques, including oral intubation, lighted stylet guided oral intubation, and nasotracheal intubation. BVM techniques may, therefore, be less desirable than the other methods of securing the airway and ventilating the patient.
Many institutions and some out-of-hospital systems use pharmacologic adjuncts, in-line cervical stabilization, and orotracheal intubation before cervical spine films are initiated. In the patient who is comatose, combative, or in severe respiratory distress without definite evidence of spinal cord injury, this approach is advocated, because it may be life saving. Precautions during intubation of the patient with known cervical spine fracture or its potential should include in-line stabilization of the cervical spine with attempts to minimize traction or lateral neck motion during the intubation procedure. Clinical experience is accumulating that supports the safety of this approach.
Potential Epiglottitis/Supraglottitis
Epiglottitis is often considered a disease of children between the ages of 2 and 8 years, but it is being recognized in adults with increasing frequency. The typical presenting picture is that of an adult or child sitting upright, drooling, or spitting up oral secretions rather than swallowing. The voice may sound muffled. There is a history of a relatively abrupt onset of a sore throat that rapidly becomes more painful. Children commonly present with a high temperature, but adults usually are only mildly febrile. The disease is especially treacherous in children because of their small airways and their tendency to panic when an oral examination or insertion of an IV line is attempted.
Small children are most calm when allowed to sit on a parent's lap. An oxygen mask with oxygen flowing at 10 L/min can be held by the parent several centimeters from the child's face. If the child is using accessory muscles to breathe, every attempt should be made to keep the child calm. If a lateral radiograph of the neck taken on inspiration can be obtained without disturbing the child, it will often establish the diagnosis. On radiography, the inflamed epiglottis often appears thickened and rounded. The hypopharynx is dilated above the obstruction.
In cases of respiratory compromise, an epiglottitis protocol should be implemented rapidly. A preestablished protocol can save many minutes of time otherwise spent trying to reach all of the personnel needed to manage this critical emergency. When a child is suspected of having epiglottitis based on history and clinical presentation, the safest course of action to establish the airway should be pursued. The emergency physician should accompany the child at all times until the airway is secure and be prepared to intervene. Otolaryngologist notification should be included in the protocol because a tracheostomy may be necessary. When operating room space or personnel are not available immediately, emergency department personnel must be prepared to manage the airway.
If the child lapses into a coma or stops making ventilatory efforts, the first step is to attempt to force oxygen past the obstruction by using mouth-to-mouth respiration or a BVM apparatus. Because the obstruction is edematous supraglottic tissue and epiglottis, positive-pressure ventilation often can displace the edema enough to allow adequate ventilation. If this effort is unsuccessful, the emergency physician should attempt oral intubation. However, a normal larynx will not be visible because of the edema. The operator should attempt to pass an endotracheal tube through the slit-like opening that remains for the supraglottic airway. An assistant can compress the chest to force bubbles through the airway, as a means of locating the airway. The assistant can also palpate the larynx and the trachea to detect the tube's entry into the trachea. If orotracheal intubation fails, the intubator should go directly to transtracheal needle ventilation (TTNV) . The obstruction of epiglottitis is mainly inspiratory, so there should be no difficulty with chest hyperinflation with intermittent TTNV. This method should ease subsequent orotracheal intubation, because the path of the airway should be readily apparent as exhaled gases pass through it.
It is recommended that all children with acute epiglottitis receive tracheal intubation. If the child is not in distress, an IV line can be established before intubation for appropriate drug administration, although some operators prefer to delay IV placement until after inhalation anesthesia.
Adults and cooperative older children with suspected epiglottitis can be examined directly. It is good practice to visualize the epiglottis and the vocal cords of the stable older patient with laryngeal tenderness who is complaining of a severe sore throat or difficulty swallowing. A mirror, fiberoptic scope, or a right-angle scope can be used to do this. In epiglottitis, the pharynx and tonsils usually do not appear inflamed, a finding that might otherwise explain the symptoms. Adults with epiglottitis do not always
need to be intubated if rigorous monitoring can be accomplished, a skilled intubator is immediately available, and the patient is not in distress. Orotracheal intubation for epiglottitis is not as difficult in adults as it is in small children. Transtracheal needle ventilation can also be used in adults who are difficult to intubate.
Jaw Clenching
Hypertonus induced by neurologic dysfunction is a common complicating factor of airway management, especially in the patient with multiple injuries, drug overdose, or seizures. Jaw clenching may be a lethal complication when it prevents clearing of blood, vomitus, or foreign bodies in the airway. No more difficult airway problem exists than occlusion of the nasal and oral passages by vomitus while the patient's teeth are tightly clenched. Respiratory efforts may lead to severe aspiration, and although the hypertonus gradually gives way as the brainstem becomes progressively hypoxic, the cerebrocortical hypoxic insult sustained in the process may be irreversible. Various disease states can lead to a similar scenario in which the jaws are clenched in the presence of upper airway hemorrhage or the accumulation of secretions.
Jaw clenching and cervical spine injury can, of course, occur together. At times, the blind nasotracheal route of intubation may be adequate for airway management while minimizing the risk of further spine injury. However, at least a small degree of spontaneous air movement should be present for the blind nasotracheal approach to be successful. Although a serendipitous success may occur in the apneic patient, it is recommended that time not be wasted on this approach in the completely apneic patient.
Neuromuscular blocking agents are generally an effective means to overcome jaw clenching in the breathing patient. Both neuromuscular depolarizing and nondepolarizing agents may be administered IV to induce paralysis and allow orotracheal intubation.
Apnea with Airway Obstruction
Despite the many nonsurgical approaches to tracheal intubation discussed in this chapter, the patient who is apneic secondary to deep airway obstruction may be served best by a surgical airway. When maneuvers to relieve airway obstruction are unsuccessful and direct laryngoscopy is not possible or cannot rapidly alleviate the obstruction and permit ventilation, the operator should rapidly move to a surgical airway approach.
CONCLUSION
Airway management is the most fundamental aspect of emergency care. Every rescuer must know basic airway maneuvers and be able to use them instinctively. When basic maneuvers fail, airway management rapidly becomes more complex. Familiarity with the ingenious intermediate airway devices can often reverse a deteriorating situation and provide the rescuer with a temporary solution to an airway dilemma. When basic and intermediate maneuvers fail, complexity, risk, and exigency mount. Choices become more critical and complications more likely. Advance consideration of situations represented in the airway management algorithms is a wise practice for the emergency physician. It may hasten accurate decision-making when time becomes critical. In this chapter we have described basic and intermediate airway techniques and offered a logical schema for their use in the patient with an acutely compromised airway. Subsequent chapters deal with the more advanced airway techniques of tracheal intubation and cricothyrotomy.
Mouth-to-mouth and BVM ventilation may suffice for out-of-hospital care with short transport times or for the initial few minutes of ventilation in cardiac arrest. However, optimal BVM ventilation during CPR is impossible. Mouth-to-mouth and BVM ventilation are adequate and effective in the anesthetized or paralyzed patient with an empty stomach in the absence of chest compression, but they are inadequate for prolonged ventilation in the patient in cardiac arrest.
Proper BVM ventilation is probably harder to master than tracheal intubation, and prolonged attempts during CPR usually only distend the stomach and give the uninitiated a false sense of security. Patients in cardiac arrest should be orotracheally intubated. Most cardiopulmonary arrests are not associated with cervical spine injury. When there is suspicion of cervical injury, the following precautions should be followed.
Potential Cervical Spine Injury
Any patient who has sustained a significant injury has the potential for cervical spine injury. Approximately 1.5 to 3.0% of initial survivors of all types of major trauma seen in emergency departments have significant cervical spine injury. It is interesting to note that this prevalence is not increased in the setting of significant head injury. Falls from heights and motor vehicle crashes are also common causes of spinal instability.
In patients with multiple injuries, the possibility of cervical spine injury warrants caution when considering tracheal intubation involving the use of the laryngoscope. It is prudent to provide adequate oxygenation while limiting neck extension until cervical spine injury is disproved. If the patient is severely hypoxic or apneic, immediate tracheal intubation may be necessary with in-line manual stabilization of the neck (without axial traction) by an assistant. When done cautiously, oral intubation of the unconscious spinal cord injured patient may be as safe as other techniques, including intubation with fiberoptic guidance.
Note that mouth-to-mouth and BVM ventilation frequently require some degree of neck extension to open the airway. A cadaver study demonstrated increased neck motion with BVM ventilation when compared to various intubation techniques, including oral intubation, lighted stylet guided oral intubation, and nasotracheal intubation. BVM techniques may, therefore, be less desirable than the other methods of securing the airway and ventilating the patient.
Many institutions and some out-of-hospital systems use pharmacologic adjuncts, in-line cervical stabilization, and orotracheal intubation before cervical spine films are initiated. In the patient who is comatose, combative, or in severe respiratory distress without definite evidence of spinal cord injury, this approach is advocated, because it may be life saving. Precautions during intubation of the patient with known cervical spine fracture or its potential should include in-line stabilization of the cervical spine with attempts to minimize traction or lateral neck motion during the intubation procedure. Clinical experience is accumulating that supports the safety of this approach.
Potential Epiglottitis/Supraglottitis
Epiglottitis is often considered a disease of children between the ages of 2 and 8 years, but it is being recognized in adults with increasing frequency. The typical presenting picture is that of an adult or child sitting upright, drooling, or spitting up oral secretions rather than swallowing. The voice may sound muffled. There is a history of a relatively abrupt onset of a sore throat that rapidly becomes more painful. Children commonly present with a high temperature, but adults usually are only mildly febrile. The disease is especially treacherous in children because of their small airways and their tendency to panic when an oral examination or insertion of an IV line is attempted.
Small children are most calm when allowed to sit on a parent's lap. An oxygen mask with oxygen flowing at 10 L/min can be held by the parent several centimeters from the child's face. If the child is using accessory muscles to breathe, every attempt should be made to keep the child calm. If a lateral radiograph of the neck taken on inspiration can be obtained without disturbing the child, it will often establish the diagnosis. On radiography, the inflamed epiglottis often appears thickened and rounded. The hypopharynx is dilated above the obstruction.
In cases of respiratory compromise, an epiglottitis protocol should be implemented rapidly. A preestablished protocol can save many minutes of time otherwise spent trying to reach all of the personnel needed to manage this critical emergency. When a child is suspected of having epiglottitis based on history and clinical presentation, the safest course of action to establish the airway should be pursued. The emergency physician should accompany the child at all times until the airway is secure and be prepared to intervene. Otolaryngologist notification should be included in the protocol because a tracheostomy may be necessary. When operating room space or personnel are not available immediately, emergency department personnel must be prepared to manage the airway.
If the child lapses into a coma or stops making ventilatory efforts, the first step is to attempt to force oxygen past the obstruction by using mouth-to-mouth respiration or a BVM apparatus. Because the obstruction is edematous supraglottic tissue and epiglottis, positive-pressure ventilation often can displace the edema enough to allow adequate ventilation. If this effort is unsuccessful, the emergency physician should attempt oral intubation. However, a normal larynx will not be visible because of the edema. The operator should attempt to pass an endotracheal tube through the slit-like opening that remains for the supraglottic airway. An assistant can compress the chest to force bubbles through the airway, as a means of locating the airway. The assistant can also palpate the larynx and the trachea to detect the tube's entry into the trachea. If orotracheal intubation fails, the intubator should go directly to transtracheal needle ventilation (TTNV) . The obstruction of epiglottitis is mainly inspiratory, so there should be no difficulty with chest hyperinflation with intermittent TTNV. This method should ease subsequent orotracheal intubation, because the path of the airway should be readily apparent as exhaled gases pass through it.
It is recommended that all children with acute epiglottitis receive tracheal intubation. If the child is not in distress, an IV line can be established before intubation for appropriate drug administration, although some operators prefer to delay IV placement until after inhalation anesthesia.
Adults and cooperative older children with suspected epiglottitis can be examined directly. It is good practice to visualize the epiglottis and the vocal cords of the stable older patient with laryngeal tenderness who is complaining of a severe sore throat or difficulty swallowing. A mirror, fiberoptic scope, or a right-angle scope can be used to do this. In epiglottitis, the pharynx and tonsils usually do not appear inflamed, a finding that might otherwise explain the symptoms. Adults with epiglottitis do not always
need to be intubated if rigorous monitoring can be accomplished, a skilled intubator is immediately available, and the patient is not in distress. Orotracheal intubation for epiglottitis is not as difficult in adults as it is in small children. Transtracheal needle ventilation can also be used in adults who are difficult to intubate.
Jaw Clenching
Hypertonus induced by neurologic dysfunction is a common complicating factor of airway management, especially in the patient with multiple injuries, drug overdose, or seizures. Jaw clenching may be a lethal complication when it prevents clearing of blood, vomitus, or foreign bodies in the airway. No more difficult airway problem exists than occlusion of the nasal and oral passages by vomitus while the patient's teeth are tightly clenched. Respiratory efforts may lead to severe aspiration, and although the hypertonus gradually gives way as the brainstem becomes progressively hypoxic, the cerebrocortical hypoxic insult sustained in the process may be irreversible. Various disease states can lead to a similar scenario in which the jaws are clenched in the presence of upper airway hemorrhage or the accumulation of secretions.
Jaw clenching and cervical spine injury can, of course, occur together. At times, the blind nasotracheal route of intubation may be adequate for airway management while minimizing the risk of further spine injury. However, at least a small degree of spontaneous air movement should be present for the blind nasotracheal approach to be successful. Although a serendipitous success may occur in the apneic patient, it is recommended that time not be wasted on this approach in the completely apneic patient.
Neuromuscular blocking agents are generally an effective means to overcome jaw clenching in the breathing patient. Both neuromuscular depolarizing and nondepolarizing agents may be administered IV to induce paralysis and allow orotracheal intubation.
Apnea with Airway Obstruction
Despite the many nonsurgical approaches to tracheal intubation discussed in this chapter, the patient who is apneic secondary to deep airway obstruction may be served best by a surgical airway. When maneuvers to relieve airway obstruction are unsuccessful and direct laryngoscopy is not possible or cannot rapidly alleviate the obstruction and permit ventilation, the operator should rapidly move to a surgical airway approach.
CONCLUSION
Airway management is the most fundamental aspect of emergency care. Every rescuer must know basic airway maneuvers and be able to use them instinctively. When basic maneuvers fail, airway management rapidly becomes more complex. Familiarity with the ingenious intermediate airway devices can often reverse a deteriorating situation and provide the rescuer with a temporary solution to an airway dilemma. When basic and intermediate maneuvers fail, complexity, risk, and exigency mount. Choices become more critical and complications more likely. Advance consideration of situations represented in the airway management algorithms is a wise practice for the emergency physician. It may hasten accurate decision-making when time becomes critical. In this chapter we have described basic and intermediate airway techniques and offered a logical schema for their use in the patient with an acutely compromised airway. Subsequent chapters deal with the more advanced airway techniques of tracheal intubation and cricothyrotomy.
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