respiratory acidosis, an abnormal condition characterized by a low plasma pH resulting from reduced alveolar ventilation. The hypoventilation inhibits the excretion of carbon dioxide, which consequently combines with water in the body to produce carbonic acid, thus reducing plasma pH. Respiratory acidosis can result from disorders such as airway obstruction, medullary trauma, neuromuscular disease, chest injury, pneumonia, pulmonary edema, emphysema, and cardiopulmonary arrest. It may also be caused by the suppression of respiratory reflexes with narcotics, sedatives, hypnotics, or anesthetics. Also called carbon dioxide acidosis. Compare metabolic acidosis. See also metabolic alkalosis, respiratory alkalosis. ▪ OBSERVATIONS: Some common signs and symptoms of respiratory acidosis are headache, dyspnea, fine tremors, tachycardia, hypertension, and vasodilation. Confirming diagnosis is usually based on a PaCO2 over the normal 45 mm Hg and an arterial pH below 7.35. ▪ INTERVENTIONS: Ineffective treatment of acute respiratory acidosis can lead to coma and death. Treatment seeks to remove or inhibit the underlying causes of associated hypoventilation. Any airway obstructions are immediately removed. Mechanical ventilation and oxygen therapy may be used, and IV bronchodilators and sodium bicarbonate may be administered. ▪ PATIENT CARE CONSIDERATIONS: The patient with respiratory acidosis is carefully monitored for any changes in arterial blood gas pressures, electrolyte concentrations, and respiratory, cardiovascular, and central nervous system functions. In patients requiring mechanical ventilation, patent airways are maintained and tracheal tubes are suctioned as needed. Adequate hydration is also important.
