Correct Answer: A

Rationale: In this case, the client's arterial blood gas results show a pH of 7.26 and a PCO2 of 49, both of which are abnormal. A pH below the normal range of 7.35-7.45 indicates acidosis. The elevated PCO2 of 49 mmHg suggests respiratory acidosis as the primary issue. The normal range for PCO2 is 35-45 mmHg, so a value of 49 indicates the retention of excess CO2, leading to acidosis. The low HCO3- level of 21 also supports the presence of metabolic acidosis; however, the primary abnormality is respiratory, making this an uncompensated respiratory acidosis. Therefore, the correct answer is 'Uncompensated respiratory acidosis.' Choice B, 'Compensated respiratory alkalosis,' is incorrect because the client's pH is acidic, not alkalotic. Additionally, there is no compensation occurring for the primary respiratory acidosis indicated by the elevated PCO2. Choice C, 'Uncompensated metabolic acidosis,' is incorrect because while the HCO3- level is low, the primary issue indicated by the elevated PCO2 is respiratory acidosis. Choice D, 'Compensated metabolic alkalosis,' is incorrect since the arterial blood gas results do not support a metabolic alkalosis. The low HCO3- level would typically be seen in metabolic acidosis, but in this case, the primary issue is respiratory acidosis.

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.

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: D

Rationale: Anemia can lead to an increased respiratory rate. In anemia, there are decreased levels of hemoglobin in red blood cells, which are responsible for carrying oxygen to the body's tissues. To compensate for the reduced oxygen-carrying capacity, the body increases the respiratory rate to bring in more oxygen. Stooped posture (Choice A) is not directly related to an increased respiratory rate. Narcotic analgesics (Choice B) are more likely to cause a decreased respiratory rate due to their central nervous system depressant effects. Injury to the brain stem (Choice C) can affect respiratory function but may not necessarily lead to an increased respiratory rate.