A 59-year-old woman with a previous diagnosis of bladder cancer, diabetes, and coronary artery disease presents to the hospital with fevers, chills, and right flank pain. She is hypotensive; empiric antibiotics are started and a central line is placed for heavy fluid resuscitation. Her temperature is 39.3°C and blood pressure is 65/40 mmHg. An arterial blood gas shows a PaO2 of 80 mmHg on supplemental oxygen with a face mask set to a fraction of inspired oxygen of 50%. A chest x-ray is ordered and shows bilateral fluffy infiltrates. A pulmonary artery catheter is advanced and records a PCWP of 22 mmHg.
Which of the following is the most likely diagnosis?
Heart failure. The findings of pulmonary edema with an elevated PCWP suggest that this patient has cardiogenic shock. The original presentation of pyelonephritis is not particularly important in answering the question, but it is likely from urinary obstruction given her history of bladder cancer. The reader’s goal here is to differentiate between cardiogenic and noncardiogenic causes of acute pulmonary edema. (C) ARDS is a potential complication of sepsis and has a high mortality. It is defined as an acute process that meets the following criteria: bilateral pulmonary infiltrates on chest imaging, severe hypoxemia (PaO2/FiO2 ratio ≤200), and normal cardiac pressures (no jugular venous distention or a PCWP <18 mmHg). Although this is a tempting answer choice, the PCWP was 22 mmHg, indicating a high left atrial pressure that is not consistent with ARDS alone; therefore a cardiac etiology should be suspected. Cardiac failure is also a consequence of sepsis, and will present with hypotension and pulmonary edema. The take home point here is to make sure the pulmonary edema is noncardiac in nature when diagnosing ARDS. (B) ALI is a milder process on the spectrum leading to ARDS, and is diagnosed with the finding of a PaO2/FiO2 ratio ≤300 but >200. This patient’s ratio is calculated at 80/0.5 = 160, and thus she would not meet the definition of ALI. (A) Anaphylaxis is a form of distributive shock that would primarily be a consequence of decreased systemic vascular resistance. The PCWP would not be elevated.
An 18-year-old girl is brought in to the hospital by her parents because of an asthma attack. She normally takes inhaled fluticasone and albuterol; however, she is not currently responding to the albuterol. On examination, she appears anxious and is moderately short of breath. There are loud bilateral wheezes on examination, with a prolonged inspiratory and expiratory phase and use of accessory muscles of respiration. Her temperature is 37.6°C, blood pressure is 118/78 mmHg, heart rate is 106 beats per minute, respiratory rate is 26 breaths per minute, and oxygen saturation is 93% on room air. She is placed on supplemental oxygen and bronchodilators and an arterial blood gas is drawn.
Arterial Blood Gas:
Which of the following is the most appropriate next step in management?
Intubation. The patient in this vignette is experiencing an acute asthma exacerbation with worrisome symptoms/signs: loud wheezes, use of respiratory accessory muscles, tachycardia, tachypnea, and poor oxygen saturation. In addition, the arterial blood gas shows a normal PaCO2, which is not a good sign; hypoxic patients should hyperventilate to maintain oxygenation, which causes hypocapnia and a respiratory alkalosis. When a patient has a normal PaCO2, this is a sign that the patient is tiring and decompensating. Even though intubation should be avoided if possible, there is a low threshold for intubating patients that are showing signs of respiratory fatigue. (A) Increasing the oxygen flow rate might improve oxygenation, but the patient is likely starting to develop hypercapnic respiratory failure, which is due to inadequate ventilation. Once the patient is on a ventilator, ventilation is controlled primarily by adjusting the respiratory rate or tidal volume. Oxygenation can be maintained by adjusting the FiO2 and positive end-expiratory pressure (PEEP). (B) IV corticosteroids are used in acute exacerbations but will not act immediately to prevent this patient from further decompensation. (C) Azithromycin and other antibiotics are used in acute COPD exacerbations, not acute asthma exacerbations.
A 24-year-old man presents to the hospital after coughing up blood. He developed a fever and a worsening cough over the past few days, with sputum that was originally yellow but became bloody this morning. Further history reveals that the patient has recurrent sinus infections and a chronic productive cough. He moved to the United States from Russia when he was 3 and has had regular medical care since that time. He is adopted and does not know his family history, and he does not smoke or use any illicit drugs. On examination, he is febrile and tachycardic. There are loud wheezes and rhonchi heard over the upper lobes bilaterally. Laboratory values are notable for a glucose of 145 mg/dL, and sputum culture is positive for Pseudomonas.
Which of the following findings would most likely be seen on a CT scan?
Dilated bronchi with wall thickening and mucus plugging. Recurrent sinopulmonary infections in a patient with an unknown family history is concerning for a possible underlying diagnosis of cystic fibrosis. In patients that present after the age of 20 due to less severe mutations in the CFTR gene, the most common manifestation is pulmonary disease (recurrent sinus infections and bronchiectasis). Other symptoms that suggest cystic fibrosis, such as diabetes or malabsorption from pancreatic insufficiency, are not as common in patients that present after the age of 20. Pseudomonas is a common colonizer in the respiratory tracts of these patients and causes recurrent infections. This patient likely has underlying bronchiectasis and is experiencing an acute exacerbation from Pseudomonas infection. A high-resolution CT will show findings of bronchiectasis: dilatation of airways with bronchial wall thickening and mucus plugging with atelectasis. Treatment with antibiotics should be initiated. Other treatments that may be useful in cystic fibrosis include β2 agonists, inhaled hypertonic saline, dornase alfa (DNase to reduce viscosity of secretions), and preventive therapy with macrolide antibiotics. (A) Mucormycosis is a necrotizing sinus infection seen in diabetics that rapidly spreads to the brain and is often fatal. It is caused most often by fungal species of Mucor and Rhizopus, not by the bacteria Pseudomonas. The patient has hyperglycemia, but a diagnosis of diabetes is not confirmed (we do not know if this is a fasting value). In addition, the physical examination did not report any erythema or necrosis of the skin around the nose, which may be seen in mucormycosis. (C) Lobar consolidation with air bronchograms is seen in lobar pneumonia; however, this is not necessarily the case in this patient (he might just have a local infection or exacerbation of bronchitis). Therefore, the better answer is (B): CT findings of bronchiectasis. (D) Bilateral hilar lymphadenopathy is suggestive of sarcoidosis and is not a prominent feature of bronchiectasis.
An older woman with a long history of smoking presents with hypercalcemia and is eventually diagnosed with lung cancer.
Which of the following types of lung cancer is most associated with this presentation?
Squamous cell carcinoma. Hypercalcemia from tumor production of parathyroid hormone-related protein (PTHrP) is a potential paraneoplastic syndrome associated with certain types of lung cancer. PTHrP acts similarly to endogenous PTH to increase serum calcium and decrease serum phosphate. The most common type of cancer associated with the release of PTHrP is squamous cell carcinoma, which can be remembered with the mnemonic “sCa2+ mous.” (B, D) Adenocarcinoma and small cell lung cancer can both produce PTHrP, but this occurs less often than with squamous cell carcinoma. Adenocarcinomas are also associated with hypertrophic osteoarthropathy (clubbing and periosteal proliferation of long bones) and a propensity to form clots. Small cell lung cancer is associated with many paraneoplastic syndromes, including ectopic ACTH production (Cushing syndrome), SIADH, and Lambert–Eaton syndrome. (C) Large cell carcinoma is a rare tumor of the lung that tends to be located peripherally and does not produce PTHrP. (E) Bronchioloalveolar carcinomas are typically found in nonsmokers and are associated with EGFR mutations.
A 42-year-old woman comes to the physician with symptoms of suprapubic discomfort, dysuria, and frequency. Her urinalysis suggests a urinary tract infection (UTI), and she is given a prescription for ciprofloxacin. Before she leaves, you notice some abnormalities in the patient’s vitals. She is afebrile with a blood pressure of 162/96 mmHg, heart rate of 86 beats per minute, respiratory rate of 19 breaths per minute, and oxygen saturation of 90% on room air. On examination, the patient is obese with a BMI of 49 kg/m2 and does not appear short of breath. She has distant heart and lung sounds, with a few faint crackles heard at the bases. An electrolyte panel is drawn, which is significant for a bicarbonate level of 32 mEq/L. An arterial blood gas is drawn and shows a pH of 7.35, PaO2 of 65 mmHg, and PaCO2 of 60 mmHg. Upon further questioning, the patient admits to daytime fatigue and loud snoring at night.
In addition to the UTI, what other diagnosis does this patient likely have that can explain her laboratory abnormalities?
Obesity hypoventilation syndrome. The main clues to this diagnosis are the following: the patient is obese, not short of breath on examination, and has evidence of chronic hypoxemia and hypercapnia measured during the daytime. These findings suggest obesity hypoventilation syndrome (Pickwickian syndrome), a disease in which there is no direct lung pathology but rather there is a problem of inadequate ventilation (therefore, the A–a gradient will be normal). The pathophysiology is multifactorial, with components of an increased work of breathing with chronic respiratory muscle fatigue, V/Q mismatch, and decreased central ventilatory drive. Besides lifestyle modifications, all patients should start noninvasive positive airway pressure during the night with either continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP). This will decrease the work of respiration while improving ventilation and therefore normalize the PaCO2 (both during the night and during the day). CPAP is preferred to BiPAP initially if the patient also has obstructive sleep apnea.
(B) Obesity hypoventilation syndrome and obstructive sleep apnea are often comorbid conditions. While obstructive sleep apnea is suggested by the patient’s snoring, daytime fatigue, and hypertension, this would not produce daytime hypoxemia and hypercapnia and therefore is not the best answer. (A) Flash pulmonary edema is an acute process that produces dyspnea. This patient is asymptomatic and the crackles heard on examination are likely from atelectasis (common in obese patients). (D) This patient does not have tachycardia or tachypnea and is not acutely symptomatic, making pulmonary embolism less likely.
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