This man, whose former occupation carries a high risk of chronic inhalational exposure to asbestos, presents with weight loss, dyspnea, cough with hemoptysis, and circumferential pleural thickening on CT scan. The occupational history, symptoms, and findings are highly suggestive of malignant pleural mesothelioma.
These findings describe the histopathologic appearance of mesothelioma. Calretinin is a biomarker found in both benign and malignant tissue of mesothelial origin. Mesothelial cells are often polygonal in shape and have long, slender microvilli, which can be seen on electron microscopy, and psammoma bodies.
A 47-year-old man is brought to the emergency department 30 minutes after he was involved in a motor vehicle collision. On arrival, he is unconscious and unresponsive to painful stimuli. His pulse is 120/min, respirations are 10/min, and his blood pressure is 88/60 mm Hg. Infusion of 0.9% saline is begun, and intubation is attempted without success. Pulse oximetry on 20 L/min of oxygen via bag-mask shows an oxygen saturation of 78%. The most appropriate next step in the management involves passing a tube through an incision in which of the following structures?
In emergency situations where a patient cannot be effectively ventilated by the conventional bag and mask ventilation or endotracheal intubation, a cricothyroidotomy is the surgical procedure of choice to restore oxygenation. A cricothyroidotomy is performed by vertically incising the skin (superficial cervical fascia, investing layer of deep cervical fascia, and pretracheal fascia) and then horizontally incising the cricothyroid membrane.
A 51-year-old man with alcohol use disorder comes to the physician because of a fever and productive cough. An x-ray of the chest shows a right lower lobe consolidation and a diagnosis of aspiration pneumonia is made. The physician prescribes a drug that blocks peptide transfer by binding to the 50S ribosomal subunit. Which of the following drugs was most likely prescribed?
Clindamycin is a bacteriostatic antibiotic that inhibits bacterial protein synthesis by preventing peptide translocation at the 50S (large) ribosomal subunit. It targets anaerobic organisms and is commonly used for the treatment of aspiration pneumonia and lung abscess, which are typically polymicrobial. Clostridioides difficile colitis is a potential complication of clindamycin.
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Respiratory System: Block 1
18/40
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A 23-year-old woman with asthma is brought to the emergency department because of shortness of breath and wheezing for 20 minutes. She is unable to speak more than a few words at a time. Her pulse is 116/min and respirations are 28/min. Pulse oximetry on room air shows an oxygen saturation of 92%. Examination of the lungs shows decreased breath sounds and scattered end-expiratory wheezing over all lung fields. Treatment with high-dose continuous inhaled albuterol is begun. This patient is at increased risk for which of the following adverse effects?
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A 44-year-old man comes to the physician because of a 5-month history of persistent cough productive of thick, yellow sputum and worsening shortness of breath. One year ago, he had similar symptoms that lasted 4 months. He has smoked two packs of cigarettes daily for the past 20 years. Physical examination shows scattered expiratory wheezing and rhonchi throughout both lung fields. Microscopic examination of a lung biopsy specimen is most likely to show which of the following findings?
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A 61-year-old woman comes to the physician because of a 5-day history of fever, headache, coughing, and thick nasal discharge. She had a sore throat and nasal congestion the week before that had initially improved. Her temperature is 38.1°C (100.6°F). Physical exam shows purulent nasal drainage and tenderness to percussion over the frontal sinuses. The nasal turbinates are erythematous and mildly swollen. Which of the following describes the microbiological properties of the most likely causal organism?
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A male newborn born at 27 weeks’ gestation is evaluated for rapid breathing and hypoxia shortly after birth. His mother had no prenatal care. Cardiopulmonary examination shows normal heart sounds, intercostal retractions, and nasal flaring. An x-ray of the chest shows low lung volumes, air bronchograms, and diffuse ground-glass opacities. He is started on nasal continuous positive airway pressure. Further evaluation of this patient is most likely to show which of the following findings?
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Two days after undergoing left hemicolectomy for a colonic mass, a 60-year-old man develops shortness of breath. His temperature is 38.1°C (100.6°F), pulse is 80/min, respirations are 22/min, and blood pressure is 120/78 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 88%. Cardiopulmonary examination shows decreased breath sounds and decreased fremitus at both lung bases. Arterial blood gas analysis on room air shows: pH 7.35 PaO2 70 mm Hg PCO2 40 mm Hg An x-ray of the chest shows collapse of the bases of both lungs. Which of the following is the most likely mechanism of this patient’s hypoxemia?
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A 3900-g (8.6-lb) male infant is delivered at 39 weeks’ gestation via spontaneous vaginal delivery. Pregnancy and delivery were uncomplicated but a prenatal ultrasound at 20 weeks showed a defect in the pleuroperitoneal membrane. Further evaluation of this patient is most likely to show which of the following findings?
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A 69-year-old man is brought to the emergency department by his wife because of fever, cough, diarrhea, and confusion for 2 days. He recently returned from a cruise to the Caribbean. He has a history of chronic obstructive pulmonary disease. He has smoked one pack of cigarettes daily for 40 years. His temperature is 39.1°C (102.4°F), pulse is 83/min, and blood pressure is 111/65 mm Hg. He is confused and oriented only to person. Physical examination shows coarse crackles throughout both lung fields. His serum sodium concentration is 125 mEq/L. Culture of the most likely causal organism would require which of the following mediums?
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A 3-year-old girl is brought to the physician by her parents because of a barking cough, a raspy voice, and noisy breathing for the last 3 days. Five days ago, she had a low-grade fever and runny nose. She attends daycare. Her immunizations are up-to-date. Her temperature is 37.8°C (100°F) and respirations are 33/min. Physical examination shows supraclavicular retractions. There is a high-pitched sound present on inspiration. Examination of the throat shows erythema without exudates. Which of the following is the most likely location of the anatomic narrowing causing this patient’s symptoms?
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A 23-year-old man is admitted to the intensive care unit with acute respiratory distress syndrome due to influenza A. He has no history of serious illness and does not smoke. An x-ray of the chest shows diffuse bilateral infiltrates. Two weeks later, his symptoms have improved. Pulmonary examination shows fewer inspiratory crackles than at the time of admission. This patient is most likely to develop which of the following long-term complications?
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A 45-year-old man with a 5-year history of worsening shortness of breath and cough comes to the physician for a follow-up examination. He has never smoked. His pulse is 75/min, blood pressure is 130/65 mm Hg, and respirations are 25/min. Examination shows an increased anteroposterior diameter of the chest. Diminished breath sounds and wheezing are heard on auscultation of the chest. An x-ray of the chest shows widened intercostal spaces, a flattened diaphragm, and basilar-predominant bullous changes of the lungs. This patient is at increased risk for which of the following complications?
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A 33-year-old woman comes to the physician because of a 3-week history of fatigue and worsening shortness of breath on exertion. There is no family history of serious illness. She does not smoke. She takes diethylpropion to control her appetite and, as a result, has had a 4.5-kg (10-lb) weight loss during the past 5 months. She is 163 cm (5 ft 4 in) tall and weighs 115 kg (254 lb); BMI is 44 kg/m2. Her pulse is 83/min, and blood pressure is 125/85 mm Hg. Cardiac examination shows a loud pulmonary component of the S2. Abdominal examination shows no abnormalities. Which of the following is the most likely cause of this patient’s shortness of breath?
12
A 61-year-old man comes to the physician because of a 9-month history of progressive shortness of breath on exertion. Pulmonary examinations shows fine bibasilar end-inspiratory crackles. There is digital clubbing. Pulmonary functions tests show an FEV1:FVC ratio of 97% and a total lung capacity of 70%. An x-ray of the chest shows small bilateral reticular opacities, predominantly in the lower lobes. A photomicrograph of a specimen obtained on lung biopsy is shown. The patient most likely works in which of the following fields?
13
A 59-year-old man comes to the physician because of a 1-year history of progressive shortness of breath and nonproductive cough. Pulmonary examination shows bibasilar inspiratory crackles. An x-ray of the chest shows multiple nodular opacities in the upper lobes and calcified hilar nodules. Pulmonary functions tests show an FEV1:FVC ratio of 80% and a severely decreased diffusing capacity for carbon monoxide. A biopsy specimen of a lung nodule shows weakly birefringent needles surrounded by concentric layers of hyalinized collagen. The patient has most likely been exposed to which of the following?
14
A 54-year-old man comes to the emergency department because of a 3-week history of intermittent swelling of his left arm and feeling of fullness in his head that is exacerbated by lying down and bending over to tie his shoes. Physical examination shows left-sided facial edema and distention of superficial veins in the neck and left chest wall. Which of the following is the most likely cause of this patient’s symptoms?
15
A 69-year-old man comes to the physician because of a 4-month history of progressive fatigue, cough, shortness of breath, and a 6.6-kg (14.5-lb) weight loss. For the past week, he has had blood-tinged sputum. He is a retired demolition foreman. There is dullness to percussion and decreased breath sounds over the left lung base. A CT scan of the chest shows a left-sided pleural effusion and circumferential pleural thickening with calcifications on the left hemithorax. Pathologic examination of a biopsy specimen of the thickened tissue is most likely to show which of the following findings?
16
A 47-year-old man is brought to the emergency department 30 minutes after he was involved in a motor vehicle collision. On arrival, he is unconscious and unresponsive to painful stimuli. His pulse is 120/min, respirations are 10/min, and his blood pressure is 88/60 mm Hg. Infusion of 0.9% saline is begun, and intubation is attempted without success. Pulse oximetry on 20 L/min of oxygen via bag-mask shows an oxygen saturation of 78%. The most appropriate next step in the management involves passing a tube through an incision in which of the following structures?
17
A 51-year-old man with alcohol use disorder comes to the physician because of a fever and productive cough. An x-ray of the chest shows a right lower lobe consolidation and a diagnosis of aspiration pneumonia is made. The physician prescribes a drug that blocks peptide transfer by binding to the 50S ribosomal subunit. Which of the following drugs was most likely prescribed?
18
A 61-year-old man comes to the physician because of a 3-month history of worsening exertional dyspnea and a persistent dry cough. For 37 years he has worked in a naval shipyard. He has smoked 1 pack of cigarettes daily for the past 40 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and pleural reticulonodular opacities. A CT scan of the chest shows pleural plaques and subpleural linear opacities. The patient is most likely to develop which of the following conditions?
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A 61-year-old man comes to the physician because of a 3-month history of worsening exertional dyspnea and a persistent dry cough. For 37 years he has worked in a naval shipyard. He has smoked 1 pack of cigarettes daily for the past 40 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and pleural reticulonodular opacities. A CT scan of the chest shows pleural plaques and subpleural linear opacities (asbestosis). The patient is most likely to develop which of the following conditions?
Bronchogenic carcinoma is the most common malignant pulmonary tumor in patients with asbestosis and the second most common carcinoma worldwide. This patient has two important risk factors, primarily a smoking history and a history of asbestos exposure
A 51-year-old man comes to the physician because of a 4-day history of fever and cough productive of foul-smelling, dark red, gelatinous sputum. He has smoked 1 pack of cigarettes daily for 30 years and drinks two 12-oz bottles of beer daily. An x-ray of the chest shows a cavity with air-fluid levels in the right lower lobe. Sputum culture grows gram-negative rods. Which of the following virulence factors is most likely involved in the pathogenesis of this patient’s condition?
Klebsiella pneumoniae possesses a capsular polysaccharide that acts as an antiphagocytic virulence factor and allows bacteria to evade host immune defenses. This pathogen is part of the natural flora of the gastrointestinal tract. In patients who are immunocompromised and patients who have an increased risk for aspiration events (e.g., due to chronic alcohol use), aspiration of Klebsiella can lead to destruction of alveoli, resulting in bloody sputum with a currant jelly appearance.
A 58-year-old man with chronic obstructive pulmonary disease and hypertension comes to the physician because of shortness of breath 3 days after starting propranolol. His temperature is 36.7°C (98.1°F), pulse is 64/min, respirations are 20/min, and blood pressure is 138/88 mm Hg. Auscultation of the lungs shows diffuse expiratory wheezes. In addition to discontinuing the propranolol (Beta-2 blockade can trigger bronchoconstriction, particularly in patients with COPD or asthma), which of the following drugs should be administered?
Albuterol is a short-acting beta-2 adrenergic agonist that induces relaxation of bronchial smooth muscle cells.
This patient has a high fever, respiratory compromise, cough with foul-smelling sputum, and infiltrates in the right lung, which is indicative of aspiration pneumonia.
Parkinson disease predisposes patients to aspiration pneumonia by impairing the swallowing and/or cough mechanism in up to 80% of those with late-stage disease. Aspiration is most likely to occur in the dependent portions of the lung (the superior segment of right lower lobe and the posterior segment of the right upper lobe when supine or the apical and posterior right lower lobe when upright)
A previously healthy 64-year-old woman comes to the physician because of a dry cough and progressively worsening shortness of breath for the past 2 months. She has not had fever, chills, or night sweats. She has smoked one pack of cigarettes daily for the past 45 years. She appears thin. Examination of the lung shows a prolonged expiratory phase and end-expiratory wheezing. Spirometry shows decreased FEV1:FVC ratio (< 70% predicted), decreased FEV1, and a total lung capacity of 125% of predicted. The diffusion capacity of the lung (DLCO) is decreased. Which of the following is the most likely diagnosis?
Smoking causes over 90% of cases of COPD, which results in decreased FEV1/FVC, decreased FEV1, and increased TLC (due to increased lung compliance).
A tall, slender young man with nontraumatic, sudden, unilateral chest pain and dyspnea most likely has a primary spontaneous pneumothorax. Imaging confirms pneumothorax and the absence of any rib fractures.
Increased right-to-left pulmonary shunting is likely to be an immediate result of primary spontaneous pneumothorax. In this functional right-to-left shunt, alveoli in collapsed lung areas are not ventilated but are still perfused with deoxygenated blood from the right heart. Perfusion of the nonventilated alveoli results in decreased oxygenation of blood flowing to the left heart (right-to-left pulmonary shunting) and hypoxia
random doctor image
Headaches, facial numbness (due to cranial nerve involvement), recurrent epistaxis, weight loss, and lymphadenopathy are suggestive of malignancy. The biopsy of this patient’s mass shows undifferentiated nasopharyngeal carcinoma, which commonly occurs in adults of Southeast Asian descent. Epstein-Barr virus (EBV) is the primary causative agent in the pathogenesis of this condition. The patient most likely acquired the causal pathogen of his nasopharyngeal mass via which of the following routes of transmission?
EBV is mainly transmitted through saliva and respiratory secretions
A 58-year-old man comes to the emergency department because of a 2-day history of dysphagia and swelling in the neck and lower jaw. He has had tooth pain on the left side over the past week, which has made it difficult for him to sleep. Four weeks ago, he had a 3-day episode of flu-like symptoms and a sore throat that resolved without treatment. He has type 2 diabetes mellitus and hypertension. Current medications include metformin and lisinopril. He appears distressed. He is 180 cm (5 ft 11 in) tall and weighs 100 kg (220 lbs); his BMI is 32 kg/m2. His temperature is 38.4°C (101.1°F), pulse is 90/min, and blood pressure is 110/80 mm Hg. Oral cavity examination shows a decayed lower left third molar with drainage of pus. There is submandibular and anterior neck tenderness and swelling. His leukocyte count is 15,600/mm3, platelet count is 300,000/mm3, and fingerstick blood glucose concentration is 250 mg/dL. Which of the following is the most likely diagnosis?
Ludwig angina is a rare and often fatal soft-tissue infection of the neck and floor of the mouth, which is known for aggressively progressing and compromising the airways. The condition is often caused by odontogenic infection, and diabetes mellitus is a predisposing factor. The patient has a molar infection along with fever, dysphagia, and swelling of the submandibular and anterior portion of the neck, which suggests that the infection has spread from the molar towards the submandibular and sublingual space. If not treated promptly with IV antibiotics (e.g., meropenem or piperacillin-tazobactam), airway control, and surgical drainage, it can be fatal.
A 62-year-old man is brought to the emergency department with fatigue, dry cough, and shortness of breath for 3 days. He reports a mild fever and has also had 3 episodes of watery diarrhea earlier that morning. Last week, he attended a business meeting at a hotel and notes some of his coworkers have also become sick. He has a history of hypertension and hyperlipidemia. He takes atorvastatin, hydrochlorothiazide, and lisinopril. He appears in mild distress. His temperature is 38.9°C (102.1°F), pulse is 56/min, respirations are 16/min, and blood pressure is 150/85 mm Hg. Diffuse crackles are heard in the thorax. Examination shows a soft and nontender abdomen. Laboratory studies show:
Hemoglobin 13.5 g/dL
Leukocyte count 15,000/mm3
Platelet count 130,000/mm3
Serum
Na+ 129 mEq/L
Cl- 100 mEq/L
K+ 4.6 mEq/L
HCO3- 22 mEq/L
Urea nitrogen 14 mg/dL
Creatinine 1.3 mg/dL
An x-ray of the chest shows interstitial infiltrates in both lungs. Which of the following is the most appropriate next step in diagnosis?
Urine antigen assay detects Legionella-soluble antigens that are present in the bacterial cell wall and excreted in urine. As this test has relatively high sensitivity (> 70%) and very high specificity (100%), it is the best initial test for diagnosing legionellosis. It is important to note, however, that this test only detects the serogroup that most commonly causes legionellosis, serogroup 1. If legionellosis is still suspected even though the urinary antigen test is negative, a culture of respiratory secretions or a polymerase chain reaction test can be performed in order to detect other serogroups of the bacteria. Fluoroquinolones (e.g., levofloxacin) are the treatment of choice for Legionnaires’ disease.
This patient has watery diarrhea in combination with signs of atypical pneumonia, including dyspnea, dry cough, and low-grade fever. These features in combination with hyponatremia and x-ray findings of bilateral patchy infiltrates suggest infection with Legionella pneumophila. Which treatment would you give?
Fluoroquinolones (e.g., levofloxacin) are the treatment of choice for legionellosis, which has two clinical manifestations, Pontiac fever and Legionnaires’ disease. Pontiac fever is a mild, flu-like condition that is self-limiting. Legionnaires’ disease manifests with atypical pneumonia and diarrhea, which is consistent with this patient’s findings. A positive urine antigen test confirms legionellosis. Acceptable second-line treatments for legionellosis include macrolides such as azithromycin.
The patient is immunocompromised and presents with acute hypoxemic respiratory failure, elevated lactate dehydrogenase and beta-D-glucan, with bilateral airspace and interstitial opacities on chest x-ray. He also has an elevated A-a gradient. The most likely diagnosis is Pneumocystis jirovecii pneumonia (PCP) and correct management is critical in order to decrease his mortality risk.
Treatment of PCP consists of trimethoprim/sulfamethoxazole, which should be initiated rapidly once PCP is suspected. Adjunctive glucocorticoids are indicated in HIV-infected patients with severe respiratory distress (PaO2 ≤ 70 mm Hg or A-a gradient ≥ 35 mm Hg), as this combination therapy has been shown to improve mortality. The addition of glucocorticoids minimizes the rapid inflammation initially caused by pathogen destruction.
Although glucocorticoids are often used for PCP in non-HIV infected patients as well, there is less data to support this and the risks and benefits should be carefully considered.
A 37-year-old woman comes to the physician because of a 2-week history of generalized fatigue and malaise. During this period, she has had a nonproductive cough with a low-grade fever. Over the past 6 months, she has had a 13-kg (28.6-lb) weight loss and intermittent episodes of watery diarrhea. She has generalized anxiety disorder and hypothyroidism. She has a severe allergy to sulfa drugs. She is sexually active with 3 male partners and uses condoms inconsistently. She has smoked one pack of cigarettes daily for 20 years and drinks 2–3 beers daily. She does not use illicit drugs. Current medications include paroxetine, levothyroxine, and an etonogestrel implant. She is 162.5 cm (5 ft 4 in) tall and weighs 50.3 kg (110.2 lb); BMI is 19 kg/m2. She appears pale. Her temperature is 38.7°C (101.6°F), pulse is 110/min, and blood pressure is 100/75 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Examination of the lungs shows bilateral crackles and rhonchi. She has white plaques on the lateral aspect of the tongue that cannot be scraped off. HIV testing is positive. A chest x-ray shows symmetrical, diffuse interstitial infiltrates. Which of the following is the most appropriate pharmacotherapy?
IV clindamycin and oral primaquine are the first-line treatment for patients with PCP who have an allergy to sulfa drugs and therefore cannot be given trimethoprim/sulfamethoxazole.
In a patient with an unknown vaccination history, symptoms of fever, respiratory distress, muffled voice, and drooling, together with tripod positioning, strongly suggest epiglottitis. The tripod position (leaning forward with hands on knees) allows patients to reduce the work of breathing by extending the neck. Which of the following is the most appropriate next step in management?
In patients with epiglottitis, emergency airway management is the most important step because respiratory distress can worsen quickly. Endotracheal intubation in children with signs of respiratory distress should be performed in a controlled environment (e.g., operating room) as soon as possible. Once the airway is secured, empirical antibiotic treatment should be initiated. Extubation should only be performed after 2–3 days of antibiotic treatment.
A 15-year-old girl comes to the physician because of a sore throat and fevers for the past 2 weeks. She has been feeling lethargic and is unable to attend school. She has a history of multiple episodes of streptococcal pharyngitis treated with amoxicillin. She immigrated with her family to the United States from China 10 years ago. She appears thin. Her temperature is 37.8°C (100°F), pulse is 97/min, and blood pressure is 90/60 mm Hg. Examination shows pharyngeal erythema and enlarged tonsils with exudates and palatal petechiae. There is cervical lymphadenopathy. The spleen is palpated 2 cm below the left costal margin. Her hemoglobin concentration is 12 g/dL, leukocyte count is 14,100/mm3 with 54% lymphocytes (12% atypical lymphocytes), and platelet count is 280,000/mm3. A heterophile agglutination test is positive. This patient’s diagnosis puts her at increased risk for which of the following?
EBV infection is associated with the development of multiple malignancies, including nasopharyngeal carcinoma, Burkitt lymphoma, and Hodgkin lymphoma. Nasopharyngeal carcinoma typically manifests with epistaxis, painless cervical lymphadenopathy, and recurrent otitis media
A previously healthy 42-year-old man is brought to the emergency department 1 hour after he was involved in a motor vehicle collision. He is conscious. He smoked one pack of cigarettes daily for 16 years but quit 8 years ago. Physical examination shows several ecchymoses over the trunk and abdomen. The abdomen is soft, and there is tenderness to palpation of the right upper quadrant without guarding or rebound. Vital signs are within normal limits. An x-ray of the chest shows no fractures; a 10-mm solid pulmonary nodule is present in the central portion of the right upper lung field. No previous x-rays of the patient are available. A CT scan of the chest is performed, which shows that the nodule has irregular, scalloped borders. Which of the following is the most appropriate next step in the management of this patient’s pulmonary nodule?
The evaluation of an incidental solitary solid pulmonary nodule involves an assessment of the nodule’s risk for malignancy. Radiological factors that increase the risk for malignancy include large nodule size (≥ 8 mm), location in the upper lung fields, and irregular, spiculated, or scalloped borders. Clinical risk factors for malignancy include age > 40 years, a history of smoking or asbestos exposure, and a positive family or personal history of malignancy. This patient’s nodule has an intermediate risk for malignancy. Accordingly, further evaluation is recommended. Positron emission tomography (PET) can determine if the nodule is metabolically active and should be considered for the evaluation of low-risk or intermediate-risk nodules, which are ≥ 8 mm. FDG-avid nodules should undergo biopsy for histopathological examination. FDG-nonavid nodules should be monitored with a follow-up CT scan. Alternatively, patients with intermediate- or high-risk nodules can proceed directly to biopsy.
If a biopsy specimen is needed to further evaluate centrally located lesions, transbronchial biopsy is recommended. For peripherally located lesions, CT-guided transcutaneous biopsy is preferred.
Positron emission tomography is conducted and indicates a malignant nodule. Bronchoscopy with transbronchial biopsy is performed and a specimen sample of the centrally located nodule is sent for frozen section analysis. Microscopic examination of the tissue sample is most likely to show which of the following?
Lung squamous cell carcinoma (SCC) is the most likely diagnosis in this patient. SCC is strongly associated with smoking and typically affects the central parts of the lung. On histology, SCC is a solid, epithelial tumor that can have intercellular bridges and keratin pearls. SCC is associated with hypercalcemia of malignancy due to the production of parathyroid hormone-related protein (PTHrP) from tumor cells. SCC was the most common type of lung cancer prior to the mid-1980s. Nowadays, lung adenocarcinoma is the most common lung cancer.
A previously healthy 2-year-old girl is brought to the emergency department by her mother because of a dry, barking cough for 2 days that worsens at night. She has also had mild rhinorrhea and fever. Her older brother has asthma and had a cold last week. Immunizations are up-to-date. She appears to be in mild distress. Her temperature is 38.1°C (100.5°F), pulse is 140/min, respirations are 35/min, and blood pressure is 99/56 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Examination shows clear rhinorrhea and a dry, hoarse cough. There is mild inspiratory stridor upon agitation that resolves with rest. The skin and oral mucosa appear normal. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate initial step in treatment?
This patient is alert and has stridor that resolves with rest, an oxygen saturation of 98% on room air, and no subcostal retractions, all of which indicate mild croup. Because croup is commonly caused by viruses (e.g., parainfluenza virus, respiratory syncytial virus), symptomatic relief is sufficient for mild cases. This includes keeping the patient calm and minimizing distress. In addition, all patients with croup should be treated with (oral or parenteral) dexamethasone, which reduces airway swelling within hours. Mild croup can quickly progress to moderate or severe croup, which can compromise the airway and manifest with stridor and dyspnea at rest, subcostal retractions, and cyanosis. Racemic epinephrine is the treatment of choice for severe croup.
Humidified air, both in the hospital and as a home remedy (e.g., steam inhalation), has been used to treat croup, but there is no evidence that it is effective.
A 26-year-old medical student comes to the physician for a chest x-ray to rule out active pulmonary tuberculosis. He needs a medical and radiological report before starting a medical internship in South Africa in 6 weeks. He says he feels well. He has no history of serious illness. He has smoked 1 pack of cigarettes daily for the past 6 years. He does not drink alcohol. He is 190 cm (6 ft 3 in) tall and weighs 75 kg (165 lbs); BMI is 20.8 kg/m2. His temperature is 37.0°C (98.6°F), pulse is 80/min, respirations are 18/min, and blood pressure is 128/89 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. The x-ray of the chest shows a small pneumothorax (rim of < 2 cm) between the upper left lung margin and the chest wall. Which of the following is the most appropriate next step in management of this patient?
Observation with follow-up serial chest x-rays are the recommended treatment for small primary spontaneous pneumothoraces with an apex-to-cupola distance < 3 cm that does not compromise the gas exchange function. A small pneumothorax is likely to resolve spontaneously within a few days (∼ 10 days).
This patient’s smoking history, male sex, young age, and physical features (tall stature, low body weight) put him at increased risk for primary spontaneous pneumothorax.
This patient presents with fever, productive cough, malaise, chills, dyspnea, and extensive opacity restricted to the upper lobe of the right lung on chest x-ray. Together, these features suggest community-acquired pneumonia. Moreover, her CURB-65 score is ≥ 2 (she is 67 years old and her respiration rate is 33/min). Which of the following is the most appropriate next step in the management?
Inpatient treatment with a combination of a macrolide and an antipneumococcal beta-lactam (e.g., azithromycin and cefotaxime) is indicated in patients with community-acquired pneumonia and a CURB-65 score ≥ 2. Hospital admission and administration of a respiratory fluoroquinolone (e.g., levofloxacin) would also be an appropriate treatment in this case. Since this patient has no further complications or risk factors such as acute respiratory failure, septic shock, or decompensation of comorbidities, ICU management is not necessary at this point.
This patient has hypoxemia during the postoperative period despite receiving 100% oxygen and has a Glasgow coma scale (GCS) score of < 9 because he is unresponsive. What should be done next?
In a patient who is unresponsive, the tongue may fall back and the pharyngeal muscles may collapse, causing airway obstruction. Given his metabolic acidosis, cardiovascular risk factors, and recent operation, this patient likely had a myocardial infarction (MI) in the postoperative period. The patient may also have a ventilation-perfusion mismatch as a result of atelectasis and/or pulmonary edema following the MI. Both of these conditions result in hypoxemia that does not improve with a high FiO2 alone, as seen here. Endotracheal intubation is necessary to secure the patient’s airways and to initiate invasive ventilation.
This patient’s symptoms (productive cough, systemic symptoms), in addition to a history of immigration from a country with a high burden of tuberculosis (TB) and the patient’s findings on chest x-ray (apical cavernous lesion and fibrosis, patchy infiltrates in upper lung fields) raise suspicion for reactivation TB. Next step?
The analysis of sputum specimens is the easiest and least invasive way to confirm suspected active pulmonary TB. Patients with suspected active TB are required to submit 3 sputum specimens, with each one used for culture, acid-fast bacilli smear microscopy, and nucleic acid amplification. The last two tests are useful for rapidly identifying active tuberculosis. Bacterial culture takes 2–6 weeks for results, but is necessary to confirm the diagnosis and test for drug susceptibility. In addition, this patient should be put on airborne precaution measures. Combination therapy consisting of isoniazid, rifampin, pyrazinamide, and ethambutol (RIPE therapy) is a treatment of choice for active tuberculosis for the first 2 months of treatment and should be started empirically after sample collection if active infection is highly suspected.
A high-resolution CT scan of the chest could be performed to further evaluate pulmonary processes (e.g., lesions that are potentially cancerous). This patient’s chest x-ray in combination with his symptoms and exposure history has already provided sufficient evidence to suspect active TB and further imaging studies are not necessary at this point.
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Anato Mnemotecnias4
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Fisio Mnemotecnias2
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Musculoesquelético26
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Comportamiento20
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Bioestadística24
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Embarazo30
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Neurología25
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Inmunología26
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Ciencias Fundamentales10
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Sangre28
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S. Reproductivo Mujer25
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S. Reproductivo Hombre30
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Endocrino20
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Respiratorio25
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Cardiología34
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Renal25
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Gastrointestinal25
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Piel20
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Multisistemico20
