Correct Answer: A

Rationale: A client with hyperkalemia may exhibit peaked T waves on an electrocardiogram. This manifestation is an early sign of high potassium levels, but diagnosis should not be based on this aspect alone. Untreated, hyperkalemia can lead to progressively worsening cardiac instability. Muscle spasms (Choice B) are more commonly associated with hypocalcemia. Constipation (Choice C) is not a typical sign of hyperkalemia. A prominent U wave on the ECG (Choice D) is associated with hypokalemia, not hyperkalemia.

Correct Answer: B

Rationale: When drawing a blood specimen from a central line, the healthcare professional should disconnect any infusions that are currently running and that could contaminate the specimen. It is important to use a minimum size of a 10 cc syringe when using a central line to avoid placing too much pressure on the catheter. Cleaning the cap with alcohol and attaching a 5 cc syringe is not appropriate as a larger syringe size should be used for this procedure. Drawing 5 cc of a blood sample to discard and flushing with saline after the sample are correct steps in the process of drawing a blood specimen from a central line.

Correct Answer: C

Rationale: The correct answer is a 58-year-old female with near-syncope. Orthostatic hypotension is a drop in blood pressure of greater than 20 mmHg systolic when moving from a sitting or lying position to standing. Patients at higher risk include those with syncope or near-syncope, symptomatic hypovolemia, and those prone to falls. The other choices are less likely to present with orthostatic hypotension. A spinal injury, altered mental status, and acute deep vein thrombosis are not directly associated with the immediate need for orthostatic hypotension measurement.

Correct Answer: B

Rationale: A lumbar puncture is performed to obtain cerebrospinal fluid for analysis to investigate various conditions affecting the client. During the procedure, the client is typically positioned on their side or sitting leaning over a table with their back rounded. The physician inserts a needle into the back around the L4-L5 vertebrae to collect the sample. Option A is incorrect because a lumbar puncture does not draw blood but instead collects cerebrospinal fluid. Option C is incorrect as the client should not necessarily lie flat for 24 hours post-procedure. Option D is incorrect as the common risks of a lumbar puncture include headache, back pain, and potential infection, not nausea, rash, or hypotension.

Correct Answer: B

Rationale: Heat exhaustion occurs when a person has enough diaphoresis that he becomes dehydrated. Intense sweating can cause both luid and electrolyte imbalances. Untreated heat exhaustion can lead to heat stroke, which results in organ damage, loss of consciousness, or death.