Sleep effects on respiration — MCQs

Which of the following physiologic changes decreases pulmonary vascular resistance (PVR)?

A mother brings her 7-year-old son to the pediatrician because she is worried about his sleep. She reports that the child has repeatedly woken up in the middle of the night screaming and thrashing. Although she tries to reassure the child, he does not respond to her or acknowledge her presence. Soon after she arrives, he stops screaming and appears confused and lethargic before falling back asleep. When asked about these events, the child reports that he cannot recall ever waking up or having any bad dreams. These events typically occur within four hours of the child going to sleep. The child’s past medical history is notable for asthma and type I diabetes mellitus. He uses albuterol and long-acting insulin. There have been no recent changes in this patient’s medication regimen. His family history is notable for obesity and obstructive sleep apnea in his father. Physical examination reveals a healthy male at the 40th and 45th percentiles for height and weight, respectively. Which of the following EEG waveforms is most strongly associated with this patient’s condition?

A 15-year-old boy is brought to the physician with excessive daytime sleepiness over the past year. His parents are concerned with his below-average school performance over the last 3 months. He goes to bed around midnight and wakes up at 7 am on school days, but sleeps in late on weekends. He exercises regularly after school. He usually has a light snack an hour before bed. He does not snore or have awakenings during sleep. He has no history of a serious illness and takes no medications. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not smoke or drink alcohol. There is no history of a similar problem in the family. His vital signs are within normal limits. His BMI is 22 kg/m2. Physical examination shows no abnormal findings. Which of the following is the most appropriate recommendation at this time?

A 25-year-old previously healthy woman is admitted to the hospital with progressively worsening shortness of breath. She reports a mild fever. Her vital signs at the admission are as follows: blood pressure 100/70 mm Hg, heart rate 111/min, respiratory rate 20/min, and temperature 38.1℃ (100.6℉); blood saturation on room air is 90%. Examination reveals a bilateral decrease of vesicular breath sounds and rales in the lower lobes. Plain chest radiograph demonstrates bilateral opacification of the lower lobes. Despite appropriate treatment, her respiratory status worsens. The patient is transferred to the intensive care unit and put on mechanical ventilation. Adjustment of which of the following ventilator settings will only affect the patient’s oxygenation?

A 21-year-old man is admitted to the intensive care unit for respiratory failure requiring mechanical ventilation. His minute ventilation is calculated to be 7.0 L/min, and his alveolar ventilation is calculated to be 5.1 L/min. Which of the following is most likely to decrease the difference between minute ventilation and alveolar ventilation?

A 64-year-old man with longstanding ischemic heart disease presents to the clinic with complaints of increasing exercise intolerance and easy fatigability for the past 2 weeks. He further states that he has been experiencing excessive daytime somnolence and shortness of breath with exertion. His wife adds that his shortness of breath is more in the recumbent position, and after approximately 2 hours of sleep, after which he suddenly wakes up suffocating and gasping for breath. This symptom is relieved after assuming an upright position for more than 30 minutes. The vital signs are as follows: heart rate, 126/min; respiratory rate, 16/min; temperature, 37.6°C (99.6°F); and blood pressure, 122/70 mm Hg. The physical examination reveals a S3 gallop on cardiac auscultation and positive hepatojugular reflux with distended neck veins. An electrocardiogram shows ischemic changes similar to ECG changes noted in the past. An echocardiogram reveals an ejection fraction of 33%. Which of the following best describes the respiratory pattern abnormality which occurs in this patient while sleeping?

A 55-year-old man presents to the physician for the evaluation of excessive daytime sleepiness over the past six months. Despite sleeping 8–9 hours a night and taking a nap during the day, he feels drowsy and is afraid to drive. His wife complains of loud snoring and gasping during the night. His blood pressure is 155/95 mm Hg. BMI is 37 kg/m2. Oropharyngeal examination shows a small orifice and an enlarged tongue and uvula. The soft palate is low-lying. The examination of the nasal cavity shows no septal deviation or polyps. Examination of the lungs and heart shows no abnormalities. Polysomnography shows an apnea-hypopnea index of 20 episodes/h. The patient is educated about weight loss, exercise, and regular sleep hours and duration. Which of the following is the most appropriate next step in management?

A 25-year-old male presents to his primary care physician with a chief complaint of anxiety and fatigue. The patient states that during this past week he has had final exams and has been unable to properly study and prepare because he is so exhausted. He states that he has been going to bed early but has been unable to get a good night’s sleep. The patient admits to occasional cocaine and marijuana use. Otherwise, the patient has no significant past medical history and is not taking any medications. On physical exam you note a tired and anxious appearing young man. His neurological exam is within normal limits. The patient states that he fears he will fail his courses if he does not come up with a solution. Which of the following is the best initial step in management?

A 35-year-old woman volunteers for a study on respiratory physiology. Pressure probes A and B are placed as follows: Probe A: between the parietal and visceral pleura Probe B: within the cavity of an alveolus The probes provide a pressure reading relative to atmospheric pressure. To obtain a baseline reading, she is asked to sit comfortably and breathe normally. Which of the following sets of values will most likely be seen at the end of inspiration?

A 57-year-old man presents to the clinic for a chronic cough over the past 4 months. The patient reports a productive yellow/green cough that is worse at night. He denies any significant precipitating event prior to his symptoms. He denies fever, chest pain, palpitations, weight changes, or abdominal pain, but endorses some difficulty breathing that waxes and wanes. He denies alcohol usage but endorses a 35 pack-year smoking history. A physical examination demonstrates mild wheezes, bibasilar crackles, and mild clubbing of his fingertips. A pulmonary function test is subsequently ordered, and partial results are shown below: Tidal volume: 500 mL Residual volume: 1700 mL Expiratory reserve volume: 1500 mL Inspiratory reserve volume: 3000 mL What is the functional residual capacity of this patient?