CHAPTER 2 Respiratory System^125
rate into acute respiratory failure. Central nervous system depression (due to
trauma or medication) or disease can also lead to acute respiratory failure.
PROGNOSIS
Patients with respiratory failure are not getting enough oxygen. This may be a sudden
event or a decompensation of a chronic respiratory condition such as emphysema or
chronic bronchitis. Supplemental oxygen and bronchodilating medications are used
to enhance airflow to the lungs. The underlying cause needs to be identified and cor-
rected to reverse the problem and return the patient to normal respiratory status.
HALLMARK SIGNS AND SYMPTOMS
- Accessory muscles used to breathe as body works harder to move air
- Difficulty breathing (dyspnea) due to lack of oxygen
- Difficulty breathing when lying down (orthopnea) due to increased work of
breathing in this position; diaphragm has to work harder; posterior chest wall
does not expand well - Fatigue due to work of breathing and lack of oxygenation
- Coughing may be due to inflammation, bronchospasm, fluid, or underlying
lung condition - Blood in sputum (hemoptysis) due to irritation of airways
- Respiration greater than 20 breaths per minute (tachypnea) in attempt to get
more air and oxygen into lungs - Sweating (diaphoresis) as body works harder to move air, using more muscles
- Cyanosis due to hypoxemia
- Anxiety due to air hunger and lack of oxygenation
- Rales (crackles) heard in the lungs if fluid builds up in alveoli and smaller
airways - Wheezing (rhonchi) due to inflammation within airways
- Diminished breath sounds due to decreased air movement
INTERPRETING TEST RESULTS
- Arterial blood gas:
- decreased oxygen PaO 2 <60 mmHg without underlying lung disease