Respiratory Acidosis Nursing Management and Interventions

Respiratory acidosis rides on top of another problem and it can move fast, so catch it early. The CO2 is climbing because the patient is not ventilating, and the pH is dropping with it. Your job is to support the airway and breathing, watch the ABGs and electrolytes, and treat the underlying cause before it tips into arrest.

What is Respiratory Acidosis?

Respiratory acidosis is an acid-base imbalance marked by increased partial pressure of arterial carbon dioxide and decreased blood pH. Prognosis tracks the severity of the underlying disturbance and the patient's overall clinical condition.

The body compensates three ways: an increased respiratory rate, hemoglobin (Hb) buffering that forms bicarbonate ions and deoxygenated Hb, and increased renal ammonia acid excretion with reabsorption of bicarbonate.

Acute respiratory acidosis goes with acute pulmonary edema, aspiration of a foreign body, sedative overdose or barbiturate poisoning, smoke inhalation, acute laryngospasm, hemothorax or pneumothorax, atelectasis, adult respiratory distress syndrome (ARDS), anesthesia and surgery, mechanical ventilators, and excessive CO2 intake (rebreathing mask, cerebral vascular accident [CVA] therapy, Pickwickian syndrome). Chronic respiratory acidosis goes with emphysema, asthma, bronchiectasis, neuromuscular disorders (Guillain-Barré syndrome, myasthenia gravis), botulism, and spinal cord injuries.

Causes

Common causes include chronic obstructive respiratory disorders (emphysema, chronic bronchitis), chest wall trauma, pulmonary edema, atelectasis, pneumothorax, drug overdose, pneumonia, and Guillain-Barré syndrome.

Complications

The dangerous endpoints are shock and cardiac arrest.

Signs and Symptoms

Look for CNS disturbances ranging from restlessness, confusion, and apprehension to somnolence with a fine flapping tremor or coma. Patients also report headache, dyspnea, tachypnea, a rise in blood pressure, mental cloudiness with a feeling of fullness in the head, and weakness.

Assessment

Assessment cues depend on the underlying cause.

Activity and rest: fatigue that ranges from mild to profound, with generalized weakness, ataxia or staggering, and loss of coordination (chronic) progressing to stupor.

Circulation: low BP or hypotension with bounding pulses, pinkish color, and warm skin (vasodilation of severe acidosis); tachycardia and irregular pulse (various dysrhythmias); diaphoresis, pallor, and cyanosis in the late stage.

Food and fluid: nausea and vomiting.

Neurosensory: a feeling of fullness in the head (acute, from vasodilation), headache, dizziness, and visual disturbances; confusion, apprehension, agitation, restlessness, somnolence, and coma (acute); tremors and decreased reflexes (severe).

Respiration: shortness of breath and dyspnea on exertion. Respiratory rate depends on the cause, decreased with respiratory center depression or muscle paralysis, otherwise rapid and shallow. Watch for increased respiratory effort with nasal flaring and yawning, use of neck and upper body muscles, hypoventilation tied to decreased respiratory center function (head trauma, oversedation, general anesthesia, metabolic alkalosis), and adventitious breath sounds (crackles, wheezes, stridor, crowing).

Teaching and learning: refer to specific plans of care that reflect the individual predisposing and contributing factors.

Diagnostic Studies

Confirm the diagnosis with arterial blood gas (ABG) analysis showing PaCO2 higher than 45 mm Hg, pH below the normal range of 7.35 to 7.45, and a bicarbonate level that is normal (acute) or elevated (chronic). Chest X-ray and CT scan help determine the cause.

On ABGs, PaO2 is normal or low and oxygen saturation (SaO2) is decreased. PaCO2 is increased, greater than 45 mm Hg (primary acidosis). Bicarbonate (HCO3) is normal or increased, greater than 26 mEq/L (compensated or chronic stage). Arterial pH is decreased, less than 7.35. On electrolytes, serum potassium is typically increased, serum chloride is decreased, and serum calcium is increased. Lactic acid may be elevated. Urinalysis shows decreased urine pH. Other screening tests follow the underlying illness or condition.

Nursing Diagnosis

Possible nursing diagnoses include impaired gas exchange, ineffective breathing pattern, ineffective tissue perfusion, acute confusion, and risk for injury.

Nursing Priorities

Achieve homeostasis, prevent or minimize complications, and provide information about the condition, prognosis, and treatment needs as appropriate.

Discharge Goals

Restore physiologic balance, keep the patient free of complications, confirm the condition, prognosis, and treatment needs are understood, and put a plan in place to meet needs after discharge.

Care Setting

Respiratory acidosis does not occur in isolation. It is a complication of a broader disease or condition, and the severely compromised patient needs admission to a medical-surgical or subacute unit.

Nursing Interventions and Considerations

Stay alert for critical changes in respiratory, CNS, and cardiovascular function, and report those changes along with any variation in ABG values or electrolyte status immediately. Maintain adequate hydration. Maintain a patent airway and provide humidification if the acidosis requires mechanical ventilation, with frequent tracheal suctioning and vigorous chest physiotherapy if ordered. Institute safety measures and assist the patient with positioning. Continuously monitor arterial blood gases.