Respiratory acidosis, an elevation in the PaCO2 level), is caused by hypoventilation with resultant excess carbonic acid. Acidosis can be due to or associated with primary defects in lung function or changes in normal respiratory pattern. The disorder may be acute or chronic.
Impaired Gas Exchange
May be related to
- Ventilation perfusion imbalance (altered oxygen-carrying capacity of blood, altered oxygen supply, alveolar-capillary membrane changes, or altered blood flow)
Possibly evidenced by
- Dyspnea with exertion, tachypnea
- Changes in mentation, irritability
- Tachycardia
- Hypoxia, hypercapnia
Desired Outcomes
- Demonstrate improved ventilation and adequate oxygenation of tissues as evidenced by ABGs within patient’s acceptable limits and absence of symptoms of respiratory distress.
- Verbalize understanding of causative factors and appropriate interventions.
- Participate in treatment regimen within level of ability/situation.
| Nursing Interventions | Rationale |
|---|---|
| Monitor respiratory rate, depth, and effort. | Alveolar hypoventilation and associated hypoxemia lead to respiratory distress or failure. |
| Auscultate breath sounds. | Identifies areas of decreased ventilation (atelectasis) or airway obstruction and changes as patient deteriorates or improves, reflecting effectiveness of treatment, dictating therapy needs. |
| Note declining level of consciousness. | Signals severe acidotic state, which requires immediate attention. Note: In recovery, sensorium clears slowly because hydrogen ions are slow to cross the blood-brain barrier and clear from cerebrospinal fluid and brain cells. |
| Monitor heart rate and rhythm. | Tachycardia develops early because the sympathetic nervous system is stimulated, resulting in the release of catecholamines, epinephrine, and norepinephrine, in an attempt to increase oxygen delivery to the tissues. Dysrhythmias that may occur are due to hypoxia (myocardial ischemia) and electrolyte imbalances. |
| Note skin color, temperature, moisture. | Diaphoresis, pallor, cool or clammy skin are late changes associated with severe or advancing hypoxemia. |
| Encourage and assist with deep-breathing exercises, turning, and coughing. Suction as necessary. Provide airway adjunct as indicated. Place in semi-Fowler’s position. | These measures improve lung ventilation and reduce or prevent airway obstruction associated with accumulation of mucus. |
| Restrict use of hypnotic sedatives or tranquilizers. | In the presence of hypoventilation, respiratory depression and CO2 narcosis may develop. |
| Discuss cause of chronic condition (when known) and appropriate interventions and self-care activities. | Promotes participation in therapeutic regimen, and may reduce recurrence of disorder. |
| Assist with identification or treatment of underlying cause. | Treatment of disorder is directed at improving alveolar ventilation. Addressing the primary condition (oversedation, lung and respiratory system trauma, pulmonary edema, aspiration) promotes correction of the acid-base disorder. |
| Monitor and graph serial ABGs, pulse oximetry readings; Hb, serum electrolyte levels. | Evaluates therapy need and effectiveness. Note: Bedside pulse oximetry monitoring is used to show early changes in oxygenation before other signs or symptoms are observed. |
| Administer oxygen as indicated. Increase respiratory rate or tidal volume of ventilator, if used. | Prevents and corrects hypoxemia and respiratory failure. Note: Must be used with caution in presence of emphysema because respiratory depression or failure may result. |
| Assist with ventilatory aids: IPPB in conjunction with bronchodilators. Monitor peak flow pressure. | Increases lung expansion and opens airways to improve ventilation, preventing respiratory failure. |
| Maintain hydration (IV/PO) and provide humidification. | Assists in correction of acidity and thinning and mobilization of respiratory secretions. |
| Provide appropriate chest physiotherapy, including postural drainage and breathing exercises. | Aids in clearing secretions, which improves ventilation, allowing excess CO2 to be eliminated. |
| Administer IV solutions such as lactated Ringer’s solution or 0.6 M solution of sodium lactate. | May be useful in nonemergency situations to help control acidosis, until underlying respiratory problem can be corrected. |
| Administer medications as indicated: | |
| Naloxone hydrochloride (Narcan) | May be useful in arousing patient and stimulating respiratory function in presence of drug overdose and sedation, or acidosis resulting from cardiac arrest. |
| Sodium bicarbonate (NaHCO3) | May be given in small IV doses in emergency situations to quickly correct acidosis if pH is less than 7.25 and hyperkalemia coexists. Note: Rebound alkalosis or tetany may occur. |
| Potassium chloride (KCl) | Replaces potassium that shifts out of cells during acidotic state. Correction of the acidosis may cause a relative serum hypokalemia as potassium shifts back into cells. Potassium imbalance can impair neuromuscular or respiratory function, causing generalized muscle weakness and cardiac dysrhythmias. |
| Bronchodilators | Helps open constricted airways to improve gas exchange. |
| Provide low-carbohydrate, high-fat diet (Pulmocare feedings), if indicated. | Helps reduce CO2 production and improves respiratory muscle function and metabolic homeostasis. |
