Ron M. Walls
The Clinical Challenge
Airway obstruction caused by a foreign body presents a unique series of challenges to the provider. First, when incomplete obstruction is present, there exists the distinct possibility that a particular action, or the failure to take specific action, could drastically worsen the situation by converting a partial obstruction to a complete obstruction. Second, when complete obstruction is present, instinctive and habitual interventions, such as bag-mask ventilation, have the potential to make the situation worse, for example, by causing a supraglottic obstruction to move below the cords, making retrieval more difficult (or impossible). Third, a common maneuver, like endotracheal intubation with bag ventilation, may meet with an unexpected result, such as the complete inability to move any air, defying the provider's attempts to find a solution to a problem perhaps never before encountered. Finally, the completely or partially obstructed airway is a unique clinical situation, requiring a specific set of evaluations and interventions, often in a very compressed period of time.
The patient with a foreign body in the airway may present with signs of upper airway obstruction or may present comatose and apneic, with only the history of onset to provide clues as to the cause of the crisis. The obstruction may be complete, as in the patient who typically has been eating, aspirates a food bolus, and is unable to move sufficient air to phonate. Although these situations usually arise in the prehospital setting, they may occasionally present to the emergency department (ED) or in-hospital. A partially obstructing foreign body will cause symptoms and signs of incomplete upper airway obstruction, specifically stridor, subjective difficulty breathing, and often a sense of fear, panic, or impending doom on the part of the patient. In many cases, there will be a preceding condition that has increased the risk of aspiration. Many patients who aspirate food are physically or mentally impaired, elderly, or intoxicated with drugs or alcohol.
Management of the suspected or known foreign body in the adult airway follows similar rationale to that used in the pediatric patient. The path chosen will depend on the patient's presentation, especially whether the foreign body is causing complete or only partial obstruction.
Approach to the Airway
Management of the foreign body in the adult airway depends on the location of the foreign body and whether the obstruction is incomplete or complete. Location may be supraglottic, infraglottic, or distal to the carina. Obstruction may be complete or incomplete. Because the precise location of the foreign body is usually not known, the following discussion focuses on the approach to the foreign body whose location is uncertain.
Incomplete Obstruction by a Foreign Body
When the patient presents with an incompletely obstructing foreign body, the most important step is to prevent the conversion of a partial obstruction to a complete obstruction. If the patient is breathing spontaneously and oxygen saturation is adequate (possibly with supplemental oxygen), then the best approach is usually to observe the patient closely for signs of complete obstruction while mobilizing the necessary providers for prompt removal in the operating room (OR). Some foreign bodies are obviously accessible and can be removed in the ED. There is risk, however, with an incompletely obstructing foreign body just proximal to the glottis, that attempts at removal in the ED might result in displacement of the foreign body into the trachea, where it is no longer amenable to removal with common ED instruments. If transfer to the OR is not an option, for example, because it would require transfer to another hospital, a decision must be made as to whether the foreign body should be removed in the ED. If so, the best approach is to handle the airway much as one would handle awake laryngoscopy for a difficult intubation (see Chapter 8). Appropriate equipment is assembled, the patient is fully preoxygenated, and then following explanation of the procedure to the patient, titrated sedation and topical anesthesia are administered. With the patient sedated, the operator carefully begins to insert the laryngoscope with the left hand, inspecting at each level of insertion before advancing to ensure that the foreign body is not pushed farther down by the tip of the laryngoscope. Either a conventional or video laryngoscope may be used. The technique is one of “lift and look” followed by a small advance (perhaps 1 cm), then another lift and look, and so on. It may be necessary to take a break to allow the patient to reoxygenate or to administer more sedation or anesthesia. When the foreign body is identified, the best instrument for removal (Magill forceps, tenaculum, towel clip) is selected. Some foreign bodies, such as hard rubber balls, cannot be grasped well with the Magill forceps. After the object is grasped and successfully removed, laryngoscopy should again be performed to ensure that no additional foreign body remains in the airway. The patient should then be observed for several hours (depending on patient condition) to ensure that there are no further complications and that no foreign body moved distally in the airway.
Upper airway foreign body without complete obstruction should be considered a genuine emergency, and an early decision must be made regarding the appropriateness of attempted removal in the ED versus expedited transfer to the OR. If, at any point, the airway becomes completely obstructed, then the patient will be managed in a manner identical with that described in the following section.
Complete Obstruction of the Airway
When airway obstruction is complete, the patient will be unable to breathe or to phonate and may hold his or her entire neck with one or both hands in the “universal choking sign.” The patient will appear terrified and will be making attempts at inspiration. In general, after complete obstruction of the airway with ensuing apnea, oxygen saturation will rapidly fall to levels incompatible with consciousness within seconds to a minute.
Initial management is dictated by whether the patient is conscious or unconscious. If the patient is conscious, the Heimlich maneuver should immediately and repeatedly be applied until either the foreign body is expelled or the patient loses consciousness. (See algorithm, Fig. 36-1.) There is no point in attempting instrumented removal of an upper airway foreign body while the patient is still conscious. If the Heimlich maneuver is successful in removing the foreign body, and the patient can phonate and breathe normally, then observation for a few hours is sufficient, and it is not mandatory to visualize the airway if the patient remains asymptomatic. If the Heimlich maneuver is unsuccessful in removing the foreign body and the patient loses consciousness, or if the patient presents unconscious with an upper airway foreign body, then the first step is immediate direct or video laryngoscopy before any attempts at bag-mask ventilation, which may cause the foreign body to move from a supraglottic to an infraglottic position. Generally, the patient will be flaccid, and it will not be necessary to administer a neuromuscular blocking agent. Time should not be lost waiting for an intravenous line to be established. Under direct or video laryngoscopy, a foreign body above the glottis should be easily identifiable. Again, Magill forceps, a tenaculum, a towel clip, or any other suitable device can be used to attempt to remove the foreign body. After removal of the foreign body, the larynx is inspected via laryngoscopy to ensure that there is no residual foreign body in the upper airway. As the foreign body is removed, the patient may begin spontaneous ventilation immediately. If the patient does not begin to breathe spontaneously, immediate intubation and initiation of positive-pressure ventilation is indicated and can be performed during the same laryngoscopy (Fig. 36-1).
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Figure 36-1 • Management of complete obstruction by a foreign body. See text for explanation. |
The laryngoscopy to remove the foreign body should be performed quickly and efficiently. If no foreign body is identified and if the glottis is clearly visualized, then either there is no foreign body or the foreign body is below the vocal cords. In this case, the patient should immediately be intubated and ventilated. If ventilation is successful, then it should be continued and resuscitation proceeds as for any other patient. If bag ventilation via the endotracheal tube meets with total resistance (no air movement, negative end-tidal carbon dioxide detection), then the trachea must be assumed to be completely obstructed. The stylet should immediately be replaced into the endotracheal tube, the cuff deflated, and the tube advanced all the way to its hilt in an attempt to push a tracheal foreign body into the right (or left) mainstem bronchus. The tube is then withdrawn to its normal level, and ventilation is attempted. The strategy here is to try to convert an obstructing tracheal foreign body (which will be lethal) to an obstructing mainstem bronchus foreign body (which can be removed in the OR). Thus, the patient can be kept alive by ventilating one lung while the other lung is obstructed.
If the down-then-up maneuver just described is not successful in establishing one-lung ventilation, there are two clinical possibilities. The only reversible situation is when the patient has one obstructed mainstem bronchus and a tension pneumothorax on the other side. Pneumothorax can occur in foreign body cases because of the abnormally high pressures generated both by the patient, while conscious, and by the rescue maneuvers. Because the operator has no way of knowing into which mainstem bronchus the foreign body was advanced (most commonly the right, but possibly the left), bilateral needle thoracostomy should be performed, in the hope of identifying a tension pneumothorax. If a pneumothorax is not identified, the second clinical possibility is complete bilateral mainstem obstruction, a condition from which survival is not possible, regardless of treatment.
Postintubation Management
Postintubation management depends on the clinical circumstances. If the foreign body has been successfully removed and the patient remains obtunded, perhaps from posthypoxemic encephalopathy, then ventilation and general management are as for any other postarrest patient. If the foreign body has been pushed down into one mainstem bronchus, the other lung must be ventilated carefully at low rates with markedly reduced tidal volumes to minimize the risk of pneumothorax while waiting for the OR.
Tips and Pearls
1. If the obstruction is incomplete, usually the best approach is to wait for definitive removal in the OR under a double setup. If you are forced to act, move slowly and deliberately to ensure that you do not convert an incomplete obstruction into a complete obstruction.
2. Call for help early.
3. If the obstructing foreign body is above the vocal cords and cannot be removed, immediate cricothyrotomy is indicated.
4. If the obstructed foreign body is distal to the vocal cords and cannot be seen from above by direct laryngoscopy, cricothyrotomy will be of little or no benefit and should not be performed.
5. The Heimlich maneuver is a reasonable first step in any case of complete obstruction and is the only maneuver that can be performed on a patient with a complete obstruction who is awake and responsive.
Evidence
1. When should I use the Heimlich maneuver versus back blows? There have been no randomized studies comparing the effectiveness of various methods for expelling an obstructing foreign body. Published reports are almost exclusively case reports and opinion pieces, and most are decades old (1,2,3). There is no clear evidence to establish the superiority of, for example, the Heimlich maneuver over simple back blows or chest thrusts. The American Heart Association (AHA), in its guidelines for emergency cardiac care, recommends that the Heimlich maneuver be done in the adult patient while conscious (4). If the maneuver is not successful despite repeated attempts, then chest thrusts or back blows can be used. Similarly, for obese patients or women late in pregnancy, chest thrusts are preferred. A cadaver study supports the use of chest thrusts rather than abdominal thrusts when the patient is unconscious, and this evidence is reflected in the AHA recommendations (5).
References
1. Penny RW. The Heimlich manoeuvre. BMJ (Clin Res Ed) 1983;286:1145–1146.
2. Redding JS. The choking controversy: critique of evidence on the Heimlich maneuver. Crit Care Med 1979;7:475–479.
3. Brauner DJ. The Heimlich maneuver: procedure of choice? J Am Geriatr Soc 1987;35:78.
4. American Heart Association. 2005 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiac care. Circulation 2005;112(Suppl 1):IV-19–IV-34.
5. Langhelle A, Sunde K, Wik L, et al. Airway pressure with chest compressions versus Heimlich manoeuvre in recently dead adults with complete airway obstruction. Resuscitation 2000;44:105–108.
