Emergencies and complications
Respiratory compromise, resulting from respiratory emergencies, is a leading cause of morbidity and mortality. Such emergencies include airway obstruction, anaphylaxis, bronchospasm, respiratory arrest, and respiratory depression; such complications include respiratory acidosis and alkalosis.
EMERGENCIES
AIRWAY OBSTRUCTION
Maintaining a patent airway is vital to life, and the body uses coughing as its main mechanism to clear the airway. However, coughing may be ineffective in clearing the airway in some disease states, or even under normal healthy conditions, if an obstruction is present.
A patient’s airway can become obstructed or compromised by vomitus, food, his teeth, blood, or saliva; however, the most common cause of airway obstruction is the tongue. That’s because muscle tone decreases when a person is unconscious or unresponsive, which increases the potential for the tongue and epiglottis to obstruct the airway.
Upper airway obstruction may also be caused by edema in associated anatomical structures. For example, edema of the tongue (caused by surgery or trauma), laryngeal edema, and smoke inhalation edema can all lead to an obstruction. Other potential causes of upper airway obstruction include:
peritonsillar, retropharyngeal, or pharyngeal abscesses
tumors of the head or neck, space-occupying lesions
tenacious secretions in the airway, bacterial or viral infections
cerebral disorders (stroke)
trauma to the face, trachea, larynx, or mediastinum, resulting in blood into nasopharynx
aspiration of a foreign object, including blood (if ruptured esophageal varices) or bits of food
fire or inhalation burns on the head, face, or neck area
croup
epiglottiditis
laryngospasms, laryngeal edema related to endotracheal intubation (after extubation)
anaphylaxis.
Pathophysiology
Upper airway obstruction is an interruption in the flow of air through the nose, mouth, pharynx, or larynx. Prompt detection and intervention can prevent a partial airway obstruction from progressing to a complete airway obstruction. However, if not recognized early, it may progress to respiratory and cardiac arrest— a life-threatening situation—and cardiopulmonary resuscitation will be required.
Complications
Cardiac and respiratory arrest
Coma
Death
Assessment findings
Signs of a partial airway obstruction can include diaphoresis, tachycardia, coughing, increased work of breathing with increased use of accessory muscles, and elevated blood pressure; however, the patient may also be asymptomatic. With a complete airway obstruction, the following symptoms may be observed:
restlessness
choking
gasping for air
wheezing, whistling, or another unusual breath sound that indicates difficulty breathing
cyanosis or pallor
cessation of coughing; the individual can’t make any sounds
change in level of consciousness (LOC) or progression to unconsciousness
agitation, panic, or increasing anxiety
hypoxia and hypercapnia
cardiac arrest.
Diagnostic test results
Physical examination may indicate decreased breath sounds. Tests, although not usually necessary to diagnose an upper airway obstruction, may include the following:
X-rays (such as chest and neck X-rays), bronchoscopy, and laryngoscopy reveal the type and site of the obstruction.
Computed tomography scanning may be ordered to rule out a tumor, a foreign body, or an infection or trauma.
Treatment
Treatment focuses on relieving the obstruction and generating oxygenation. (See Opening an obstructed airway.)
Prompt assessment should focus on determining the cause of the obstruction. When an obstruction is related to the tongue or an accumulation of tenacious secretions, place the head in a slightly extended position and insert an oral airway. If the patient has a complete airway obstruction, can’t cough or speak, and a foreign body obstruction is suspected, a series of abdominal thrusts are performed in an attempt to remove the foreign object. (See Obstructed airway management, pages 376 to 378.)
If an upper airway obstruction is deemed an emergency, the following procedures are warranted.
CRICOTHYROTOMY
Cricothyrotomy involves the excision of the cricothyroid membrane below the thyroid cartilage and the cricoid ring. A tracheostomy tube is placed through this opening to keep the newly created airway open until a tracheotomy can be performed. The tube is typically uncuffed and has an inner diameter large enough for a small catheter. This procedure is used when no other option is available to establish an airway; for example, if the setting is outside of the hospital. It should be converted to a tracheostomy if the patient still needs airway support after 24 hours. (See Performing an emergency cricothyrotomy, pages 379 and 380.)
OPENING AN OBSTRUCTED AIRWAY
To open an obstructed airway, use the head-tilt, chin-lift maneuver or the jaw-thrust maneuver, as described here.
Head-tilt, chin-lift maneuver
In many cases of airway obstruction, the muscles controlling the patient’s tongue have relaxed, causing the tongue to obstruct the airway. If the patient doesn’t appear to have a neck injury, use the head-tilt, chin-lift maneuver to open his airway. Use these four steps to carry out this maneuver:
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Place your hand closest to the patient’s head on his forehead.
Apply firm pressure—firm enough to tilt the patient’s head back.
Place the fingertips of your other hand under the bony portion of the patient’s lower jaw, near the chin.
Lift the patient’s chin. Be sure to keep his mouth partially open (as shown at right). Avoid placing your fingertips on the soft tissue under the patient’s chin because this may inadvertently obstruct the airway you’re trying to open.
Jaw-thrust maneuver
If you suspect a neck injury, use the jaw-thrust maneuver to open the patient’s airway. Use these four steps to carry out this maneuver:
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Kneel at the patient’s head with your elbows on the ground.
Rest your thumbs on the patient’s lower jaw near the corners of his mouth, pointing your thumbs toward his feet.
Place your fingertips around the lower jaw.
To open the airway, lift the lower jaw with your fingertips (as shown at right).
ENDOTRACHEAL INTUBATION
Endotracheal (ET) intubation involves the insertion of a tube into the trachea through the nose (nasotracheal intubation) or the mouth (orotracheal intubation). Many facilities have guidelines limiting the use of nasotracheal intubation for specific patient populations, including certain types of trauma, head and neck surgery, and difficult intubations. Nasotracheal intubation not only increases patient discomfort but increases the risk of sinus infection.
OBSTRUCTED AIRWAY MANAGEMENT
An obstructed airway causes anoxia, which in turn leads to brain damage and death in 4 to 6 minutes. The Heimlich maneuver uses an upper-abdominal thrust to create sufficient diaphragmatic pressure in the static lung below the foreign body to expel the obstruction. The Heimlich maneuver is used in conscious adult patients and in children older than age 1. However, the abdominal thrust is contraindicated in pregnant women, markedly obese patients, and infants younger than age 1. For such patients, use a chest thrust, which forces air out of the lungs to create an artificial cough.
These maneuvers are contraindicated in a patient with mild airway obstruction, when the patient can maintain adequate ventilation to dislodge the foreign body by effective coughing, and in an infant. However, if the patient has poor air exchange and increased breathing difficulty, a silent cough, cyanosis, or the inability to speak or breathe, take immediate action to dislodge the obstruction.
Conscious adult with mild airway obstruction
Ask the person who’s coughing or using the universal distress sign (clutching the neck between the thumb and fingers) if she’s choking. If she indicates that she is but can speak and cough forcefully, she has good air exchange and should be encouraged to continue to cough. Remain with the person and monitor her.
Conscious adult with severe airway obstruction
Ask the person, “Are you choking?” If the patient nods yes and has signs of severe airway obstruction, tell her that you’ll help dislodge the foreign body.
Stand behind the patient and wrap your arms around her waist. Make a fist with one hand, and place the thumb side against her abdomen in the midline, slightly above the umbilicus and well below the xiphoid process. Grasp your fist with the other hand (as shown below).
Squeeze the patient’s abdomen with quick inward and upward thrusts. Make each thrust a separate and distinct movement, forceful enough to create an artificial cough that will dislodge an obstruction (as shown below).
Make sure that you have a firm grasp on the patient because she may lose consciousness and need to be lowered to the floor. Support her head and neck to prevent injury, and continue as described.
Repeat the thrusts until the foreign body is expelled.
If the patient becomes unconscious, contact the emergency medical service (EMS) and follow the interventions for relieving an obstructed airway in an unconscious person. If the victim of an airway obstruction becomes unconscious, the lay rescuer should lower the patient to the ground and immediately contact the EMS and begin cardiopulmonary resuscitation (CPR). Studies demonstrate that chest thrusts generated higher sustained airway pressure than pressure generated by abdominal thrusts. For this reason, it’s believed that chest compressions alone may relieve the obstruction in the unconscious victim.
Unresponsive adult
Lower the patient to the ground and immediately contact the EMS.
Begin CPR.
Each time the airway is opened using a head-tilt, chin-lift maneuver, look for an object in the patient’s mouth.
Remove the object, if present.
Attempt to ventilate the patient and follow with 30 chest compressions.
The blind finger sweep is no longer recommended by the American Heart Association; it should be used only when a foreign body can be seen in the mouth. Studies have shown that blind finger sweeps may result in injury to the patient’s mouth and throat or to the rescuer’s fingers, and there’s no evidence as to its effectiveness. In addition, the tongue-jaw lift is no longer used. Open the patient’s mouth using a head-tilt, chin-lift maneuver.
Obese or pregnant adult
If the patient is conscious, stand behind her and place your arms under her armpits and around her chest.
Place the thumb side of your clenched fist against the middle of the sternum, avoiding the margins of the ribs and the xiphoid process. Grasp your fist with your other hand and perform a chest thrust with enough force to expel the foreign body. Continue until the patient expels the obstruction or loses consciousness (as shown below).
If the patient loses consciousness, carefully lower her to the floor.
Then, follow the same steps you would use for the unresponsive adult.
Conscious child with severe airway obstruction
If the child is conscious and can stand but can’t cough or make a sound, perform abdominal thrusts using the same technique you would with an adult.
Unresponsive child
Use the same techniques you would for the unresponsive adult.
Conscious infant
Place the conscious infant face down so that he’s straddling your arm with his head lower than his trunk. Rest your forearm on your thigh and deliver five forceful back blows with the heel of your hand between the infant’s shoulder blades (as shown below).
If you haven’t removed the obstruction, place your free hand on the infant’s back. Supporting his neck, jaw, and chest with your other hand, turn him over onto your thigh. Keep his head lower than his trunk.
Position your fingers. To do so, imagine a line between the infant’s nipples and place the index finger of your free hand on his sternum, just below this imaginary line. Then place your middle and ring fingers next to your index finger and lift the index finger off his chest. Deliver five quick chest thrusts as you would for chest compression at a rate of approximately one per second.
Never perform a blind finger sweep on a child or an infant because you risk pushing the foreign body farther back into the airway. Also, abdominal thrusts aren’t recommended for infants because they may damage the liver.
If the airway obstruction persists, repeat the five back blows and five chest thrusts until the obstruction is relieved or the infant becomes unresponsive.
Unresponsive infant
Use the same techniques you would for the unresponsive adult.
Continue until the obstruction is relieved or help arrives.
TRACHEOTOMY
Tracheotomy involves incising the skin over the trachea, thus creating a surgical wound for placement of a tube to establish an airway (tracheostomy). (See Combating tracheotomy complications.) However, this procedure may also be performed electively to prevent damage to the larynx such as when mechanical ventilation is necessary for more than 1 week.
PERFORMING AN EMERGENCY CRICOTHYROTOMY
To perform an emergency cricothyrotomy, first put on sterile gloves and clean the patient’s neck with a sterile gauze pad soaked in chlorhexidine solution. To reduce the risk of contamination, use a circular motion, working outward from the incision site.
Locate the precise insertion site by sliding your thumb and fingers down to the thyroid gland. You’ll know you’ve located its outer borders when the space between your fingers and thumb widens.
Move your finger across the center of the gland, over the anterior edge of the cricoid ring.
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Using a scalpel
Make a horizontal incision, less than ½″ (1.3 cm) long, in the cricothyroid membrane just above the cricoid ring.
Insert a dilator to prevent tissue from closing around the incision. If a dilator isn’t available, insert the handle of the scalpel and rotate it 90 degrees (as shown at top of next column).
If a small tracheostomy tube (#6 or smaller) is available, insert it into the opening and secure it to help maintain a patent airway. If a tracheostomy tube isn’t available, tape the dilator or scalpel handle in place until a tracheostomy tube is available.
If the patient can breathe spontaneously, attach a humidified oxygen source to the tracheostomy tube with a T tube; if he can’t, attach a handheld resuscitation bag. You’ll need to inflate the cuff of the tracheostomy tube with a syringe to provide positive-pressure ventilation.
Auscultate bilaterally for breath sounds, and take the patient’s vital signs.
Dispose of the gloves properly and wash your hands.
Using a needle
Attach a 10-ml syringe to a 14G (or larger) through-the-needle or over-theneedle catheter. Then insert the catheter into the cricothyroid membrane just above the cricoid ring.
Direct the catheter downward at a 45-degree angle, as shown at top of next page, to the trachea to avoid damaging the vocal cords. Maintain negative pressure by pulling back the syringe plunger as you advance the catheter. You’ll know the catheter has entered the trachea when air enters the syringe.
When the catheter reaches the trachea, advance it and remove the needle and syringe. Tape the catheter in place.
Attach the catheter hub to one end of the I.V. extension tubing. At the other end, attach a hand-operated release valve or a pressure-regulating adjustment valve. Connect the entire assembly to an oxygen source.
Press the release valve to introduce oxygen into the trachea and inflate the lungs. When you can see that they’re inflated, release the valve to allow passive exhalation. Adjust the pressure-regulating valve to the minimum pressure needed for adequate lung inflation.
Auscultate bilaterally for breath sounds, and take the patient’s vital signs.
Dispose of the gloves properly and wash your hands.
COMBATING TRACHEOTOMY COMPLICATIONS
This chart lists possible tracheotomy complications along with measures to prevent, detect, and treat them.
COMPLICATION | PREVENTION | DETECTION | TREATMENT |
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Aspiration |
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Bleeding at tracheotomy site |
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Infection at tracheotomy site |
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Pneumothorax |
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Subcutaneous emphysema |
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Tracheal malacia |
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Nursing interventions
The following serve as guidelines when caring for a patient with an upper airway obstruction.
Recognize that an upper airway obstruction is a medical emergency.
Assess for the cause of the obstruction.
Assess breath sounds.
Monitor chest X-rays and arterial blood gas results after the obstruction is relieved.
Observe for “seesaw” respirations, use of accessory muscles, or retractions.
Apply pulse oximetry to assess the patient’s oxygenation status, and administer oxygen, as needed.
Continually assess for stridor, cyanosis, and changes in LOC, and notify the practitioner immediately.
Perform abdominal thrusts if a foreign object obstruction is suspected.
Prepare for a cricothyrotomy if the setting is outside of the health care environment.
Prepare for ET intubation or a tracheotomy if an airway can’t be established.
Anticipate cardiac arrest if the obstruction isn’t cleared promptly.
ANAPHYLAXIS
Anaphylaxis is a dramatic, acute atopic reaction marked by the sudden onset of rapidly progressive urticaria and respiratory distress. A severe reaction may initiate vascular collapse, leading to systemic shock and, possibly, death.
Anaphylactic reactions result from systemic exposure to sensitizing drugs or other specific antigens. Such substances may be serums (usually horse serum), vaccines, allergen extracts (such as pollen), enzymes (L-asparaginase), hormones, penicillin and other antibiotics, sulfonamides, local anesthetics, salicylates,
polysaccharides (such as iron dextran), diagnostic chemicals (sodium dehydrocholate, radiographic contrast media), foods (chocolate, legumes, nuts, berries, seafood, egg albumin) and sulfite-containing food additives, insect venom (honeybees, wasps, hornets, yellow jackets, fire ants, and certain spiders) and, rarely, a ruptured hydatid cyst.
polysaccharides (such as iron dextran), diagnostic chemicals (sodium dehydrocholate, radiographic contrast media), foods (chocolate, legumes, nuts, berries, seafood, egg albumin) and sulfite-containing food additives, insect venom (honeybees, wasps, hornets, yellow jackets, fire ants, and certain spiders) and, rarely, a ruptured hydatid cyst.
The most common anaphylaxis-causing antigen is penicillin. This drug induces a reaction in 1 to 4 of every 10,000 patients treated with it. Penicillin is also most likely to induce anaphylaxis after parenteral administration or prolonged therapy.
Pathophysiology
An anaphylactic reaction requires previous sensitization or exposure to the specific antigen. After initial exposure to an antigen, the immune system responds by producing specific immunoglobulin (Ig) antibodies in the lymph nodes. Helper T cells enhance this process. These IgE antibodies then bind to membrane receptors located on mast cells (found throughout connective tissue, typically near small blood vessels) and basophils.
When the body encounters the antigen again, the IgE antibodies, or cross-linked IgE receptors, recognize the antigen as foreign. This activates a series of cellular reactions that trigger degranulation—the release of chemical mediators (such as histamine, prostaglandins, and platelet-activating factor) from mast cell stores. IgG or IgM enters the reaction and activates the release of complement factors. (See What happens in anaphylaxis.)
Complications
Death minutes to hours after the first symptoms (although a delayed or persistent reaction may occur for up to 24 hours)
Respiratory obstruction
Systemic vascular collapse
Assessment findings
Signs and symptoms of anaphylaxis may include:
exposure to an antigen
feeling of impending doom or fright
apprehension
restlessness
cyanosis
UP CLOSE
WHAT HAPPENS IN ANAPHYLAXISAn anaphylactic reaction requires previous sensitization or exposure to the specific antigen. The following illustrates the anaphylactic process.
1. Response to the antigen
Immunoglobulin (Ig) M and IgG recognize the antigen as a foreign substance and attach themselves to it.
The process to destroy the antigen (the complement cascade) begins but can’t finish, either because of insufficient amounts of the protein catalyst A or because the antigen inhibits certain complement enzymes. The patient exhibits no signs or symptoms at this stage.
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2. Released chemical mediators
The antigen’s continued presence or reintroduction activates IgE, which promotes the release of mediators, including histamine, serotonin, and leukotrienes.
The sudden release of histamine causes vasodilation and increases capillary permeability, resulting in a loss of circulating plasma, thus decreasing blood pressure. The patient begins to exhibit sudden nasal congestion; itchy, watery eyes; flushing; sweating; weakness; and anxiety.
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3. Intensified response
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