A nurse in an emergency department is caring for a client who has a sucking chest wound resulting from a gunshot. The client has a blood pressure of 100/60 mm Hg, a weak pulse rate of 118/min, and a respiratory rate of 40/min. Which of the following actions should the nurse take?

Choice A Reason: This is incorrect because respiratory alkalosis is characterized by a high pH and a low PaCO2, indicating that the client is hyperventilating and losing too much carbon dioxide.

Choice B Reason: This is incorrect because metabolic acidosis is characterized by a low pH and a low bicarbonate level, indicating that the client has an excess of metabolic acids or a loss of base.

Choice C Reason: This is incorrect because metabolic alkalosis is characterized by a high pH and a high bicarbonate level, indicating that the client has an excess of base or a loss of metabolic acids.

Choice D Reason: This is correct because respiratory acidosis is characterized by a low pH and a high PaCO2, indicating that the client is hypoventilating and retaining too much carbon dioxide.

Choice A Reason: This choice is incorrect because inserting a central line is not a priority action for a client who has a sucking chest wound. A central line is a catheter that is inserted into a large vein in the neck, chest, or groin to administer fluids, medications, or blood products. It may be indicated for clients who have hypovolemia, sepsis, or shock, but it does not address the underlying cause of the client's respiratory distress.

Choice B Reason: This choice is incorrect because removing the dressing to inspect the wound may worsen the client's condition. A sucking chest wound is an open wound in the chest wall that allows air to enter and exit the pleural cavity with each breath. This creates a positive pressure in the pleural space that collapses the lung on the affected side and shifts the mediastinum to the opposite side, impairing the ventilation and circulation of both lungs. Therefore, the nurse should apply an occlusive dressing that covers three sides of the wound and allows air to escape but not enter the pleural cavity. Removing the dressing may allow more air to enter and increase the risk of tension pneumothorax, which is a life-threatening complication.

Choice C Reason: This choice is correct because administering oxygen via nasal cannula may help to improve the client's oxygenation and ventilation. A nasal cannula is a device that delivers oxygen through two prongs that fit into the nostrils. It can provide oxygen at low flow rates (1 to 6 L/min) and low concentrations (24 to 44 percent). The nurse should monitor the client's respiratory rate, pulse oximetry, and arterial blood gases to assess the effectiveness of oxygen therapy.

Choice D Reason: This choice is incorrect because raising the foot of the bed to a 90° angle may worsen the client's respiratory distress. This position may increase the pressure on the diaphragm and reduce the lung expansion. It may also decrease the venous return and cardiac output, leading to hypotension and shock. Therefore, the nurse should position the client in a semi-Fowler's position (30 to 45° angle) or high-Fowler's position (60 to 90° angle) to facilitate breathing and prevent further complications.