Fast Breathing (Tachypnea)
Tachypnea is usually significant at rates above 20. A low oxygen, a high CO2, or a low pH (or combinations) may cause tachypnea, seen in asthma, pneumonia, CHF, exacerbations of COPD and DKA. Other conditions causing tachypnea are emotional reactions (i.e., hyperventilation), pulmonary embolism, pneumothorax, obesity (increased vessel resistance), pain (increased nervous stimulation), anemia (decreased oxygen) and hyperthyroidism (increased metabolic rate). An increased respiratory rate is also seen with sympathomimetric drugs, as well as aspirin, methanol, ethylene glycol and carbon monoxide poisonings. Treatment is directed at correcting the underlying condition.
Although hyperventilation is usually the result of anxiety, ife-threatening conditions such as pulmonary embolism, diabetic ketoacidosis and sepsis must first be ruled out. Carbon dioxide is blown off, creating respiratory alkalosis. The person presents with a feeling of shortness of breath, lightheadedness and tingling in the hands, feet and mouth (decreased CO2 causes cerebral vasoconstriction, reduced cerebral blood flow and paresthesias). The alkalosis causes increased binding of calcium to plasma protein, decreasing the amount of ionized calcium in the bloodstream. The low calcium results
in spasms of skeletal muscles (tetany), and the person often arrives in the emergency department in carpal spasm. This reverses as the CO2 returns to normal.
Treatment: carbon dioxide is restored by decreasing the respiratory rate in a quiet environment (breathing into a paper bag should be avoided because of the potential for hypoxia).
Slow Breathing (Bradypnea)
A slow respiratory rate is usually significant at a rate of 8 or less per minute. Often this is an emergency and requires immediate therapy. Conditions causing bradypnea are the ingestion of drugs (i.e., alcohol, narcotics, sedativehypnotics), increased intracranial pressure from trauma and hemorrhage (pressure on the respiratory center), severe respiratory depression (i.e., CO2 narcosis) and coma from any cause. It is seen in many pre-arrest and end-stage conditions.
Treatment: assisted ventilation is often required with a bag-valvemask (BVM). Endotracheal intubation is frequently necessary.
This type of irregular respiratory pattern is observed in terminal situations where tachypnea alternates with apnea. It is seen in severe central nervous system injuries such as stroke, hypertensive encephalopathy, brain swelling from trauma with impending herniation (increased intracranial pressure) and in severe heart failure. The cause is an altered cerebral response to CO2. Overbreathing is present when the CO2 is elevated, then apnea occurs to restore the CO2. In severe heart failure, the sluggish circulation causes a delay and overcorrection of the acid-base status.
In some obese individuals, drowsy episodes accompanied by snoring and apneic spells occur. This obstructive sleep apnea is caused by one or more anatomic abnormalities. The tongue falls back during sleep and blocks the airway. Treatment involves weight loss, avoidance of alcohol and nasal continuous positive airway pressure (nasal CPAP) at night. Resection of pharyngeal soft tissue may be required.
Abnormal Respiratory Sounds
1. Snoring respirations are sometimes caused by the tongue falling back in the throat, partially obstructing the upper airway. A jaw thrust or chin lift corrects the situation.
2. Stridor is the high-pitched sound of air moving through a partially obstructed upper airway.
3. Decreased breath sounds in a portion of a lung (usually the base) may be caused by a pneumothorax, hemothorax or a large pleural effusion.
4. Rales (pronounced “rahls”, also called crackles) are sounds like tissue paper being squeezed, indicating fluid in the small airways and alveoli.
5. Rhonchi are rattling sounds from mucous and fluid in the large airways (bronchi).
6. Wheezes are musical sounds produced by air moving through narrowed bronchi and bronchioles.
Labored Breathing (Dyspnea)
The most common cause of upper airway obstruction is a decreased level of consciousness from any cause. The tongue falls back in the mouth, partially obstructing the airway. Treatment is a jaw thrust or chin lift, and insertion of a nasopharyngeal or oropharyngeal airway.
Signs of upper airway obstruction include snoring respirations, shortness of breath, cyanosis, hoarseness, difficulty in swallowing (dysphagia) or speaking, stridor, coughing, grunting or tachypnea in any combination. In the pediatric population, tachypnea, chest retractions and nasal flaring are often prominent. Causes are foreign bodies, trauma, allergic reactions and infection. These are frequently medical emergencies. Treatment depends on the specific problem. Foreign bodies may be removed manually. With trauma
patients, if intubation is not possible, a cricothyrotomy is performed. An allergic reaction involving the upper airway (angioedema) or a systemic reaction (anaphylaxis) is treated with epinephrine, antihistamines and steroids.
Common lower airway problems causing dyspnea are asthma, COPD, pneumonia, pulmonary edema, pulmonary embolism/infarction and pneumothorax.