A nurse is instructing a school-age child who has asthma about the use of a peak expiratory flow meter.

Which of the following instructions should the nurse include in the teaching?

The nurse should first administer oxygen at 2 L/min via nasal cannula because the client has signs of hypoxemia (low oxygen saturation) and respiratory distress (increased respiratory rate) that may worsen the chest pain and myocardial ischemia. Oxygen therapy can help improve oxygen delivery to the heart muscle and reduce the workload of the heart.
The nurse should then administer sublingual nitroglycerin as prescribed because nitroglycerin is a vasodilator that can help relieve chest pain by dilating the coronary arteries and improving blood flow to the heart. Nitroglycerin can also lower blood pressure and reduce cardiac preload and afterload, which can decrease myocardial oxygen demand.
Other choices:

• Prepare the client for cardiac catheterization: This may be a later intervention if the chest pain persists or if the client has a confirmed myocardial infarction, but it is not the first priority for the nurse. Cardiac catheterization is an invasive procedure that involves inserting a catheter into a large artery and advancing it to the coronary arteries to visualize any blockages or stenosis. The procedure may also involve angioplasty or stent placement to restore blood flow to the affected area.

• Request a prescription for an increase in statin: This may be a long-term intervention to lower the client’s LDL cholesterol and prevent further plaque formation in the coronary arteries, but it is not an immediate intervention for chest pain. Statins are lipid-lowering drugs that can reduce the risk of cardiovascular events in clients with CAD, but they do not have a direct effect on chest pain or myocardial ischemia.

• Check a STAT cardiac troponin: This may be a diagnostic test to confirm or rule out a myocardial infarction, but it is not an intervention for chest pain. Cardiac troponin is a protein that is released into the bloodstream when there is damage to the heart muscle. Elevated levels of cardiac troponin indicate a myocardial infarction or other cardiac injury.

• Request a prescription for a beta-blocker: This may be an adjunctive therapy to reduce chest pain and prevent complications, but it is not the first-line intervention for chest pain. Beta-blockers are drugs that block the effects of adrenaline on the heart and blood vessels, which can lower heart rate, blood pressure, and myocardial oxygen demand. Beta-blockers can also prevent arrhythmias and reduce mortality in clients with CAD.

This instruction will help the client to prevent venous stasis and thrombosis, which are common postoperative complications. Range-of-motion exercises promote blood circulation and prevent muscle atrophy and contractures.

Choice B. “Use an incentive spirometer every 4 hours.” is wrong because it is not related to promoting circulation, but rather to improving lung expansion and preventing atelectasis and pneumonia. Using an incentive spirometer is also important for postoperative clients, but it does not address the question.

Choice C. “Remain on bed rest for 24 hours following the procedure.” is wrong because it is the opposite of promoting circulation.

Bed rest increases the risk of venous stasis, thrombosis, and pulmonary embolism. Postoperative clients should be encouraged to ambulate as soon as possible, unless contraindicated.

Choice D. “Place a pillow under your knees while in bed.” is wrong because it also impairs circulation and increases the risk of thrombosis.

Placing a pillow under the knees can cause pressure on the popliteal veins and reduce blood flow. Postoperative clients should avoid this position and keep their legs in a neutral or slightly elevated position.