Correct Answer: D

Rationale: The peak expiratory flow rate is the most important indicator of respiratory function in asthma because it measures how quickly air can be exhaled, reflecting the severity of airflow limitation. Oxygen saturation (Choice A) is important in assessing oxygenation, but it does not directly reflect respiratory function. Respiratory rate (Choice B) can provide information on breathing patterns but does not quantify airflow limitation. Arterial blood gases (Choice C) give information about gas exchange but are not as specific for assessing asthma control and severity as peak expiratory flow rate.

Correct Answer: C

Rationale: Correct Answer: The correct answer is C, 'Hyperkalemia.' Sodium polystyrene sulfonate (Kayexalate) is a medication used to treat high potassium levels (hyperkalemia) by exchanging sodium ions for potassium ions in the intestines, leading to potassium removal from the body. Therefore, the nurse should monitor the client for changes in potassium levels to assess the effectiveness of the medication and prevent potential complications related to hyperkalemia. Choice A, 'Hyponatremia,' is incorrect as Kayexalate does not primarily affect sodium levels. Choice B, 'Hypokalemia,' is incorrect as Kayexalate is used to treat high potassium levels, not low. Choice D, 'Hypocalcemia,' is incorrect as Kayexalate does not directly impact calcium levels.

Correct Answer: B

Rationale: Obtaining a urethral drainage specimen for culture is crucial in diagnosing a potential sexually transmitted infection (STI) in this client. While assessing for perineal symptoms like itching, erythema, and excoriation (Choice C) may provide additional information, obtaining a culture is more definitive. Observing for a chancroid-like lesion (Choice A) is not as pertinent as obtaining a culture for a broader diagnostic approach. Identifying all sexual partners in the last four days (Choice D) is important for contact tracing but obtaining a specimen for culture takes priority in this scenario.

Correct Answer: A

Rationale: The correct answer is A. Learning is best demonstrated by a change in behavior. A client who can safely and correctly perform the procedure shows they have acquired the skill. Choice B is incorrect because critiquing the nurse's performance does not directly demonstrate the client's ability to perform the procedure. Choice C is incorrect because explaining the steps does not guarantee the client can physically perform the injection. Choice D is incorrect as answering a posttest only assesses theoretical knowledge, not practical application.

Correct Answer: D

Rationale: The expected increase in hematocrit after transfusion is approximately 3% per unit of PRBCs. Since the client received 4 units, the expected increase would be 4 x 3% = 12%. Therefore, adding this to the pretransfusion hematocrit of 17% would result in an expected post-transfusion hematocrit of 29%. Choice A (0.19) is incorrect as it doesn't consider the incremental increase per unit of PRBCs. Choices B (0.09) and C (0.39) are also incorrect as they do not align with the expected increase in hematocrit following the transfusion of 4 units of PRBCs.