A nurse is caring for a client in the emergency department (ED) who has high anxiety and shallow respirations at a rate of 30/min. Which of the following acid-base disturbances is the client most likely experiencing?

A. Apply positive pressure ventilation and provide supportive care with pain management: While supportive care is important, positive pressure ventilation may not be sufficient to address the underlying issue, which is likely a pneumothorax or hemothorax.
B. Perform needle decompression of the pleural space followed by chest tube insertion: This is the most appropriate initial management for a patient with paradoxical chest wall movement, which is a sign of flail chest and likely pneumothorax. Needle decompression can relieve pressure in the pleural space, and chest tube insertion can help drain any fluid or air that has accumulated.
C. Administer intravenous antibiotics and arrange for an elective surgical repair: While infection may be a concern, it is not the most immediate priority in this case. The patient's respiratory distress needs to be addressed first.
D. Provide high-flow oxygen and intubate the patient for mechanical ventilation: While oxygen therapy may be necessary, intubation should be considered as a last resort if other measures fail to improve oxygenation. In this case, needle decompression and chest tube insertion are more likely to be effective in improving respiratory function.

A. ARDS is characterized by severe hypoxemia due to shunting, but it typically impairs oxygenation rather than carbon dioxide elimination. The primary issue is the inability to oxygenate blood, not the elimination of carbon dioxide.
B. In ARDS, pulmonary arterial pressure often increases due to pulmonary hypertension caused by widespread inflammation and hypoxemia, not decreased pressure. V/Q mismatch contributes to hypoxemia but does not directly cause decreased pulmonary arterial pressure.
C. While hypoxemia is a hallmark of ARDS, it is primarily due to shunting (where blood passes through unventilated areas of the lung) rather than dead space, which is more associated with conditions like pulmonary embolism.
D. ARDS involves decreased pulmonary compliance due to the stiffness of the lungs, which results from diffuse alveolar damage and the formation of hyaline membranes. This stiffness makes it difficult for the lungs to expand, leading to reduced oxygenation and severe hypoxemia.