Page 283 - Saunders Comprehensive Review For NCLEX-RN

Box 9-1

Causes of Respiratory Acidosis

▪ Asthma: Spasms resulting from allergens, irritants, or emotions cause the
smooth muscles of the bronchioles to constrict, resulting in ineffective gas
exchange.
▪ Atelectasis: Excessive mucus collection, with the collapse of alveolar sacs caused
by mucous plugs, infectious drainage, or anesthetic medications, results in
ineffective gas exchange.

▪ Brain trauma: Excessive pressure on the respiratory center or medulla oblongata
depresses respirations.
▪ Bronchiectasis: Bronchi become dilated as a result of inflammation, and
destructive changes and weakness in the walls of the bronchi occur.
▪ Bronchitis: Inflammation causes airway obstruction, resulting in inadequate gas
exchange.
▪ Central nervous system depressants: Depressants such as sedatives, opioids, and
anesthetics depress the respiratory center, leading to hypoventilation (excessive
sedation from medications may require reversal by opioid antagonist
medications); carbon dioxide (CO ) is retained and the hydrogen ion
2
concentration increases.
▪ Emphysema and chronic obstructive pulmonary disease: Loss of elasticity of
alveolar sacs restricts air flow in and out, primarily out, leading to an increased
CO level.
2
▪ Hypoventilation: CO is retained and the hydrogen ion concentration increases,
2
leading to the acidotic state; carbonic acid is retained and the pH decreases.
▪ 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 cause obstruction in a pulmonary artery resulting in
airway obstruction and inadequate gas exchange.

Table 9-1

Clinical Manifestations of Acidosis

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