A 33-year-old construction worker comes for evaluation and treatment of acute onset of low back pain. He notes that the pain is an aching located in the lumbosacral area. It has been present intermittently for several years; there is no known trauma or injury. He points to the left lower back. The pain does not radiate and there is no numbness or tingling in the legs or incontinence. He was moving furniture for a friend over the weekend. On physical examination, you note muscle spasm, with normal deep tendon reflexes and muscle strength. What is the most likely cause of this patient's low back pain?

Correct Answer: C

Rationale: The correct answer is C: Mechanical low back pain. This is the most likely cause as the patient's pain is aching, located in the lumbosacral region, intermittent for years, with no radiation, numbness, tingling, or incontinence. The physical exam findings of muscle spasm, normal reflexes, and muscle strength support this diagnosis. Mechanical low back pain is common and often related to muscle strain or overuse, as seen in this construction worker who was moving furniture. Choice A (Herniated disc) is incorrect as the patient does not have radiation of pain or neurological symptoms. Choice B (Compression fracture) is unlikely without a history of trauma or injury. Choice D (Ankylosing spondylitis) is less likely given the lack of inflammatory symptoms and typical age of onset.

Correct Answer: C

Rationale: The correct answer is C: Counseling on smoking cessation. Smoking is a major risk factor for numerous health issues such as cardiovascular disease, respiratory problems, and cancer. Given the patient's age, history of smoking, and other risk factors like depression and hyperlipidemia, counseling on smoking cessation is crucial to improve her overall health and reduce the risk of future complications. Choice A: Counseling on starting aspirin may be appropriate for some individuals based on their cardiovascular risk profile, but in this case, smoking cessation is a more urgent priority due to the direct impact of smoking on health. Choice B: Counseling on alcohol cessation is important, but in this scenario, smoking cessation takes precedence due to the immediate and significant health risks associated with smoking. Choice D: Counseling on mammogram is important for breast cancer screening, but addressing smoking cessation should be the primary focus given the patient's current health risks. In summary, counseling on smoking cessation is the most critical intervention for this patient to improve her overall health

Correct Answer: C

Rationale: The correct answer is C: Atherosclerosis. Atherosclerosis is the most common cause of erectile dysfunction in older men as it leads to reduced blood flow to the penis, affecting the ability to achieve and maintain an erection. Psychological stress (A) can contribute to erectile dysfunction but is not the primary cause. Adverse drug reactions (B) can also lead to erectile dysfunction, but it is not as common as atherosclerosis. Autonomic neuropathy (D) can affect nerve impulses in the penis but is not as prevalent as atherosclerosis in causing erectile dysfunction in older men.

Correct Answer: C

Rationale: The correct answer is C. In this scenario, the patient had a radical prostatectomy and external beam radiation therapy, indicating aggressive treatment. Despite this, the PSA level is high (24.5 ng/mL), suggesting biochemical recurrence and possible metastasis. The positive bone scan and enlarged pelvic lymph node indicate disease progression beyond the prostate. Chemical or surgical castration, such as androgen deprivation therapy, can help delay disease progression and prolong survival by reducing the levels of testosterone that fuel prostate cancer growth. Summary: A: In advanced dementia and metastatic bone disease, castration is unlikely to impact survival as the disease is already advanced. B: A rising PSA level post-radical prostatectomy with negative imaging indicates biochemical recurrence, but without evidence of metastasis, making castration less beneficial. D: Prostate cancer limited to the prostate with a Gleason score of 6 is low risk and may not benefit significantly from castration as it is less likely to progress rapidly.

Correct Answer: D

Rationale: The correct answer is D: Either vancomycin or fidaxomicin are recommended for the first episode of C. difficile infection. 1. Choice A is incorrect because metronidazole is no longer recommended as first-line treatment due to increasing resistance. 2. Choice B is incorrect because there is no evidence suggesting older adults require a longer duration of treatment with vancomycin for their first episode. 3. Choice C is incorrect because while fecal transplantation can be used in refractory cases, it is not typically the first-line treatment. 4. The rationale for D being correct is that both vancomycin and fidaxomicin are recommended as first-line treatments for the initial episode of C. difficile infection based on current guidelines. This allows for flexibility in selecting the appropriate antibiotic based on individual patient factors.