References:
- Saunders Comprehensive Review for the NCLEX-RN Examination, 9th Edition, ISBN 978-032-37-9530-2, by Linda Anne Silvestri, Angela E. Silvestri, and Jessica Grimm (Ch. 8, pp. 106-115)
The total number of buffer base is lower than normal, with a relative increase in hydrogen ion concentration; thus, a greater number of hydrogen ions are circulating in the blood than can be absorbed by the buffer system. It may be caused by:
- Primary defects in the function of the lungs or changes in normal respiration patterns.
- Any condition that causes an obstruction of the airway leading to hypoventilation or respiratory system depression.
| Cause | Description |
|---|---|
| Asthma | spasms resulting from allergens, irritants, or emotions, resulting in ineffective gas exchange. |
| Atelectasis | Excessive mucus collection with the collapse of alveolar sacs caused by mucous plugs, infectious drainage, or anesthetic medications, resulting in ineffective gas exchange. |
| Brain Trauma | Respiratory depression may occur from pressure placed on the medulla oblongata or respiratory center. |
| Bronchiectasis | Abnormal dilation of the bronchial airways from inflammation, and destructive changes and weakness in the bronchial walls occur. |
| Bronchitis | Inflammation causes airway obstruction, resulting in ineffective gas exchange. |
| Central Nervous System Depressants | Sedatives, opioids, and anesthetics depress the respiratory center, leading to hypoventilation. CO2 becomes retained. Reversal of excessive sedation may require opioid antagonists. |
| Emphysema and COPD | The loss of alveolar sac elasticity restricts ventilation (mostly in exhalation), leading to increased CO2 levels. |
| Hypoventilation | CO2 is retained and the hydrogen ion concentration increases. Carbonic acid is retained, decreasing pH and creating an acidotic state. |
| Pneumonia | Excess mucus production and lung congestion cause airway obstruction, resulting in inadequate gas exchange. |
| Pulmonary Edema | Extracellular accumulation of fluid in pulmonary tissue causes disturbances in alveolar diffusion and perfusion. |
| Pulmonary Emboli | Emboli obstruct pulmonary arteries, resulting in airway obstruction and inadequate gas exchange. |
Assessment
- Neurological: lethargy, confusion, dizziness, headache, coma
- Cardiovascular: decreased blood pressure; dysrhythmias (from hyperkalemia during compensation); warm, flushed skin (from peripheral vasodilation)
- Gastrointestinal: no significant findings
- Neuromuscular: muscle weakness and seizures
- Respiratory: increased rate and depth as compensation. If unable to compensate, hypoventilation and hypoxia occur
Interventions
- Monitor for signs of respiratory distress.
- Administer O2 as prescribed.
- Place the client in a semi-Fowler’s position.
- Encourage and assist the client to turn, cough, and deep-breathe.
- Reduce restlessness by improving ventilation rather than by administering tranquilizers, sedatives, or opioids, as these further depress respirations.
- Prepare to administer respiratory treatments as prescribed; suction the client’s airway if necessary.
- Prepare for endotracheal intubation and mechanical ventilation if severe acidosis and CO2 levels rise above 50 mm Hg (normally 21 to 28 mm Hg) and signs of acute respiratory distress are present.
Airway Obstruction
If the client has a condition that causes an obstruction of the airway or depresses the respiratory system, monitor the client for respiratory acidosis.