Correct Answer: C

Rationale: The correct answer is an echocardiogram. This diagnostic test is crucial in assessing ventricular function and identifying the cause of shortness of breath in a client with heart failure. It provides valuable information about the heart's structure, function, and blood flow. While a chest X-ray may show signs of heart failure, it does not directly assess cardiac function like an echocardiogram does. Arterial blood gases (ABGs) are useful to evaluate oxygenation and acid-base balance but do not provide information specific to heart function. An electrocardiogram (ECG) assesses the heart's electrical activity and rhythm, which is important but may not provide the detailed structural information needed in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Potassium of 6.0 mEq/L. A potassium level of 6.0 mEq/L is dangerously high in a client with CKD, and it should be reported before hemodialysis to prevent cardiac complications. High potassium levels can lead to life-threatening arrhythmias. Choices A, B, and D are not the most critical values to report before hemodialysis. While a serum potassium level of 5.5 mEq/L is slightly elevated, it is not as urgent as a level of 6.0 mEq/L in this context. Hemoglobin of 10 g/dl and blood glucose of 200 mg/dl are important parameters to monitor but are not as immediately concerning before hemodialysis compared to a high potassium level.

Correct Answer: C

Rationale: Mucous plugging of the tracheostomy tube is the most concerning assessment finding in a client with a tracheostomy. It can lead to airway obstruction, which requires immediate intervention to ensure the client's airway remains patent. Crepitus around the tracheostomy site may indicate subcutaneous emphysema but is not as urgent as a blocked airway. A dry and cracked tracheostomy site may indicate poor skin integrity but does not pose an immediate threat to the client's airway. Yellowing of the skin around the tracheostomy site could suggest a localized infection, but it is not as critical as a potential airway obstruction caused by mucous plugging.

Correct Answer: B

Rationale: Serum troponin is the most specific and sensitive indicator of myocardial infarction. Troponin levels rise within 3-4 hours after myocardial damage, peak at 10-24 hours, and remain elevated for up to 10-14 days. Creatine kinase (CK) and myoglobin can also be elevated in myocardial infarction, but troponin is more specific to cardiac muscle damage. C-reactive protein (CRP) is a marker of inflammation and is not specific for myocardial infarction.

Correct Answer: B

Rationale: The correct answer is B: History of cardiac arrhythmia. Clozapine can lead to severe cardiovascular problems, making it crucial to report any history of cardiac arrhythmia to the healthcare provider before administering the medication. Choices A, C, and D are less concerning in this context as they are not directly associated with potential serious complications related to clozapine use.