A client who had orthopedic surgery three days ago verbalizes difficulty in sleeping. Which initial intervention is best for the practical nurse (PN) to implement?

This finding requires immediate action, as it indicates that the client is not receiving the prescribed amount of oxygen, which can compromise the oxygenation and perfusion of the tissues. The PN should adjust the flowmeter to deliver 3 liters per minute of oxygen, and check for any leaks or kinks in the tubing.

The other options are not correct because:

B. The absence of a humidifier does not require immediate action, as it is not a critical component of the oxygen delivery system. A humidifier can help moisten the dry oxygen and prevent mucosal irritation, but it is not essential for oxygenation.

C. The supine position does not require immediate action, as it is not a contraindication for oxygen therapy. The client may prefer this position for comfort or rest, and it does not affect the oxygen delivery or uptake.

D. The snug fit of the cannula does not require immediate action, as it is not a problem for oxygen therapy. The cannula should fit snugly against the client's cheeks to prevent dislodgment or slippage, and it does not interfere with the oxygen flow or diffusion.

Troponin I and CK-MB are cardiac enzymes that are released into the bloodstream when the heart muscle is injured or necrotic. Elevated levels of these enzymes indicate that the client has suffered a myocardial infarction (MI) or heart atack. The damaged heart tissue can impair the electrical conduction system of the heart and cause abnormal heart rhythms or dysrhythmias, which can be life-threatening. The PN should monitor the client's cardiac status closely and report any changes to the charge nurse.

The other options are not correct because:

1. The client is not at risk for pulmonary embolism, which is a blockage of a pulmonary artery by a blood clot or other material. Pulmonary embolism does not cause elevated cardiac enzymes, but it can cause chest pain, shortness of breath, and hypoxia.
2. The client is not at risk for recurrent long-term angina pain, which is chest pain caused by reduced blood flow to the heart muscle due to narrowed or blocked coronary arteries. Angina pain does not cause elevated cardiac enzymes, but it can be a warning sign of an impending MI.
3. The lab results do not indicate risk factors for transient ischemic atack (TIA), which is a temporary interruption of blood flow to a part of the brain due to a clot or plaque. TIA does not cause elevated cardiac enzymes, but it can cause neurological symptoms such as weakness, numbness, or speech difficulties.