A nurse is teaching a client who has tuberculosis and is to start medication therapy with isoniazid, rifampin, and pyrazinamide. Which of the following instructions should the nurse include?

Increased anteroposterior diameter of the chest, also known as barrel chest, is a common finding in clients who have COPD with emphysema. It is caused by chronic air trapping and hyperinflation of the lungs, which results in fattening of the diaphragm and widening of the rib cage.

a) Oxygen saturation level 96% is within the normal range of 95% to 100% and does not indicate hypoxemia or impaired gas exchange. Clients who have COPD with emphysema typically have lower oxygen saturation levels, ranging from 88% to 92%.
b) Respiratory alkalosis is a condition in which the blood pH is elevated due to decreased carbon dioxide levels. It is caused by hyperventilation, which can occur in response to hypoxia, anxiety, or pain. Clients who have COPD with emphysema usually have respiratory acidosis, which is a condition in which the blood pH is lowered due to increased carbon dioxide levels. It is caused by hypoventilation, which results from impaired lung function and airway obstruction.
d) Petechiae on chest are small red or purple spots on the skin caused by bleeding from capillaries. They are not a typical finding in clients who have COPD with emphysema, unless they have severe coughing episodes or coagulation disorders. They can indicate infection, inflammation, trauma, or vascular disease.

This statement indicates an understanding of the teaching, as weight loss is one of the most effective ways to decrease the number of nightly apneic episodes in clients who are obese and have obstructive sleep apnea. Obstructive sleep apnea is a condition in which the upper airway collapses or becomes blocked during sleep, causing pauses in breathing and hypoxia. Obesity is a major risk factor for obstructive sleep apnea, as excess fat tissue around the neck and throat can narrow the airway and increase its collapsibility. Losing weight can reduce the pressure on the airway and improve its patency.

b) "I sleep better if I take a sleeping pill at night." This statement indicates a lack of understanding of the teaching, as sleeping pills are not recommended for clients who have obstructive sleep apnea. Sleeping pills can worsen the condition by relaxing the muscles of the throat and tongue, which can further obstruct the airway and decrease the arousal response to hypoxia. The nurse should advise the client to avoid sleeping pills and other sedatives or alcohol before bedtime.
c) "It might help if I tried sleeping only on my back." This statement indicates a lack of understanding of the teaching, as sleeping on the back is not helpful for clients who have obstructive sleep apnea. Sleeping on the back can increase the risk of airway obstruction by allowing gravity to pull the tongue and soft palate backward, which can block the airway and cause snoring and apnea. The nurse should suggest that the client try sleeping on the side or elevate the head of the bed to prevent this.
d) "I should get a humidifier to run at my bedside at night." This statement indicates a lack of understanding of the teaching, as a humidifier is not likely to decrease the number of nightly apneic episodes in clients who have obstructive sleep apnea. A humidifier can moisten the air and ease breathing for clients who have dry or irritated nasal passages, but it does not address the underlying cause of airway obstruction or hypoxia. The nurse should inform the client that a humidifier may not be effective for obstructive sleep apnea and may increase the risk of infection or mold growth if not cleaned properly.