A 75-year-old patient with pneumonia presents with fever, tachycardia, and confusion. His temperature is 39.5°C (103.1°F). The attending physician explains that fever speeds up metabolic reactions in the body, including immune responses and bacterial proliferation. Which of the following best explains why higher temperature increases reaction rates?
Which of the following strategies has shown the strongest evidence for increasing bicycle helmet use and reducing injury in children and adolescents?
Which of the following statements about motorcycle helmet use laws and their effects is most accurate?
A 45-year-old man with a history of recurrent nephrolithiasis is started on a medication to reduce his risk of future kidney stone formation. This medication works by increasing calcium reabsorption in exchange for sodium secretion in the distal convoluted tubule. Which of the following medications was most likely prescribed?
A 52-year-old man with a history of hypertension is prescribed atenolol to manage his blood pressure. Which of the following best describes the effect of atenolol on intracellular cyclic adenosine monophosphate (cAMP) levels in cardiac myocytes?
A 58-year-old man with a history of chronic heart failure presents to the clinic for follow-up. He reports that he gets short of breath when walking around the house or performing simple tasks like cooking and doing light chores. He no longer attempts activities like grocery shopping due to the severity of his symptoms. However, when resting or sitting down, he feels fine and does not experience shortness of breath. What is his NYHA Functional Classification for heart failure?
A 22-year-old man is brought to the emergency department after a motorcycle accident. He was initially briefly unconscious, but then regained full consciousness and reported feeling fine. However, one hour later, he became confused and drowsy, and his right pupil is now dilated and nonreactive. A non-contrast CT scan of the head shows a biconvex (lentiform) hyperdense collection that does not cross suture lines. Which of the following is the most likely diagnosis?
A 16-year-old female presents to her pediatrician for a routine check-up, reporting difficulty waking up for school at 6:30 AM. She states she can’t fall asleep until around 2 AM despite trying to go to bed earlier. She feels groggy and occasionally dozes off during morning classes but is alert after lunch. She plays soccer after school, which keeps her energized until 7 PM, and she naps for an hour some afternoons. On weekends, she sleeps from 2 AM to noon without issue. She keeps a sleep log for two weeks, showing 5-6 hours of sleep on weekdays and 10-11 hours on weekends. She avoids caffeine, has no screen time after 10 PM, and denies snoring. Physical exam reveals a healthy teenager with a BMI of 21 kg/m², normal blood pressure, and no signs of depression or anxiety. What is the most likely diagnosis for this patient’s sleep difficulties?
Patient Case: Narcolepsy Chief Complaint: “I keep falling asleep during the day, even when I don’t want to.” History of Present Illness: A 20-year-old male college student presents to the sleep clinic with a 1-year history of excessive daytime sleepiness (EDS). He reports frequently falling asleep in class, during conversations, and even while eating. Despite getting 7–8 hours of sleep each night, he feels constantly tired and struggles to stay awake during the day. He also describes episodes where he suddenly loses muscle control and collapses when laughing or feeling excited, though he remains fully conscious during these events. He reports experiencing vivid, dream-like hallucinations just before falling asleep and occasional episodes of waking up unable to move for several seconds. There is no history of head trauma, drug use, alcohol use, or psychiatric illness. He denies snoring, choking sensations during sleep, or frequent nighttime awakenings. Past Medical History: No significant medical conditions Medications: None Family History: No family history of sleep disorders Social History: College student, non-smoker, occasional caffeine use, no recreational drug use Review of Systems: Positive: Excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations, cataplexy episodes. Negative: No night sweats, no weight loss, no history of depression Physical Examination: • General: Alert and cooperative, appears fatigued • Neurologic: Normal motor strength, reflexes, and coordination • Cardiovascular: Normal heart rate and blood pressure • Respiratory: No signs of upper airway obstruction Diagnostic Workup: 1.Polysomnography (PSG): •Normal nighttime sleep duration •No significant apnea/hypopnea events •Increased sleep fragmentation 2.Multiple Sleep Latency Test (MSLT): •Mean sleep latency: <8 minutes •REM sleep within 15 minutes in ≥2 naps (sleep-onset REM periods, or SOREMPs) 3.Cerebrospinal Fluid (CSF) Hypocretin-1 Levels: Low hypocretin-1 levels (<110 pg/mL) Which of the following is the most appropriate initial pharmacological treatment for this patient’s cataplexy associated with his sleep disorder?
