B4.060 - CBCL Pulmonary Infections Flashcards
what is A mostly consisting of
Neutrophils
In acute lobar pneumonia, the alveolar infiltrate consists mainly of neutrophils. Macrophages are also present, but are normally present in all alveoli. Some fibrin deposition is also usually seen, and can form a network for eventual organization and scarring if antibiotics are not started early in the course of the disease.
During a cardiac arrest, a 58-year-old man, non-smoker, receives cardiopulmonary resuscitative measures and is brought to the hospital, where he is intubated. During the intubation procedure, he suffers aspiration of gastric contents. Over the next 10 days he develops a non-productive cough along with a fever to 37.9° C. A chest x-ray reveals a 4 cm diameter mass with an air-fluid level in the right lung. A gram stain of bronchoalveolar lavage reveals mixed flora. What condition is he most likely to have?
lung abscesses
Mixed flora are usually found in gastric contents, and may give rise to an abscess, which is diagnosed by the chest x-ray revealing an air fluid level within the abscess. Typical organisms are staphylococcus aureus and anaerobic organisms.
The purulent, liquefied center of the abscess can produce the radiographic appearance of
air-fluid level
A 52-year-old woman has had an increasingly severe cough productive of yellowish sputum for several days. On physical examination, her temperature is 38.9°C, and diffuse crackles are heard in the left lower lung. A chest x-ray shows left lower lung consolidation. Laboratory studies show a WBC count of 11,990/mm3 with 72% segmented neutrophils, 8% bands, 16% lymphocytes, and 4% monocytes. The representative gross appearance of the lung is depicted in the attached photograph. Which of the following pathogens is most likely to be cultured from the patient’s sputum?
Streptococcus pneumoniae
The productive cough suggests an alveolar exudate with neutrophils, and the course is compatible with an acute infection. Bacterial organisms should be suspected. Pneumococcus is the most likely agent to be cultured in persons acquiring a pneumonia outside of the hospital setting, and particularly when a lobar pneumonic pattern is present, as in this case.
where is klebsiella found and what are key features
Klebsiella pneumoniae comes from the GI tract and is a less common etiologic organism, usually present with aspiration or in individuals with a suppressed immune system. The sputum produced from a Klebsiella pneumonia is red and jelly-like.
first choice antibiotic for mycoplasma
macrolides, like azithromycin
when do you commonly see food particles
in aspiration pneumonia
describe the red hepatization phase
During red hepatization phase, the alveoli are filled with neutrophils, erythrocytes, and fibrin.
Mycoplasma primarily affects what part of the lung
interstitium, doesnt cause alveolar filling so not found on lung exams usually.
what does a lung abcsess look like
an area of liquefactive necrosis filled with tissue debris and neutorphils
A 54-year-old woman was diagnosed with influenza 10 days ago. She was not vaccinated, but received oseltamivir 2 days after her symptoms began. Over the following week, he symptoms began to resolve. However, she then began to have increasing fever, cough, shortness of breath, and malaise. She presented to the ER. On physical examination, her temperature is 37.9°C. There are inspiratory crackles on auscultation of the chest. Her chest x-ray shows diffuse infiltrates. She is able to provide a sputum sample. The gram stain is shown below. What is the most likely etiologic organism?
staph aureus
A 28-year-old college student presents with 1-day history of dry cough, headache, fever, and myalgias. She just returned to the dormitory after winter break. On exam, she her temperature is 38.2° C and she appears fatigued. Her lung exam is unremarkable. What is the best next step?
Rapid flu swab.
This patient is presenting with classic influenza symptoms during the normal season of peak incidence. She should be given a mask to wear to prevent spread by respiratory droplets and a rapid flu swab should be done right away, keeping in mind that false negative results can occur.
A 79-year-old woman with hypertension and chronic kidney disease, was diagnosed with community-acquired pneumonia by her primary care provider when she presented with a cough and was found to have patchy infiltrates on her chest x-ray. She is allergic to fluoroquinolones and was given a prescription for cefdinir. 2 days later, she presents to the ER with worsening dry cough, fever of 40° C, headache, and diarrhea. She requires ICU admission. Which organism should be on the differential diagnosis?
Legionella pneumophila
Legionella is an under-diagnosed cause of community-acquired pneumonia. Because it is an intra-cellular bacterium, it doesn’t respond to beta-lactam antibiotics, which is why the patient described deteriorated when treated with a cephalosporin; macrolides are typically effective. The water systems of large buildings, such as hotels, are frequently colonized with Legionella.
The clinical presentation typically involves a predominantly dry cough, diarrhea and high fevers.
An 85-year-old in the Emergency Room just diagnosed with community acquired pneumonia has a CURB-65 score of 3 based on presence of confusion, BUN 30, respiratory rate 26, blood pressure 110/70 and age. Based on his CURB score of 3, how should his pneumonia be treated?
In the intensive care unit.
Admission to the hospital is recommended when the patient’s CURB-65 score is ≥2 and many patients with scores of ≥3 will require admission to the ICU.
pseudomonas is usually associated with whate exposure
healthcare exposure
recent hospitalization, hemodialysis
most commonly implicated pathogen in lung abscesses
staph aureus
but anaerobes such as Bacteroides, Peptococcus, and Fusobacterium may also be implicated. These anaerobes normally are found in the oral cavity and hence are readily aspirated.
Nocardial and actinomycotic infections often lead to
chronic abscesses, but these lack a liquified component and typically affect immunocompromised persons.
(a) The dominant finding in P. jiroveci pneumonia is a foamy intra-alveolar exudate.
(b) and (c) GMS staining highlights P. jiroveci organisms. When viewed from the correct angle, the organism’s cup-like shape is apparent (arrows).
describe the congestion phase of lobar pneumonia
congestion phase, during which vascular congestion occurs and the alveoli begin to fill with neutrophils and edema.
A 56-year-old woman who struggles with alcoholism presents to the ER in alcohol withdrawal. Her vital signs are pertinent for T 38.2° C, HR 110, and O2 sat 86% on room air. Her WBC count is 14,000. During her evaluation, she is coughing and asks for an emesis basin. When she hands it back to you, you see it contains red, gelatinous sputum. What is the likely diagnosis?
klebsiella pneumonia
It is normal flora of the GI tract and thus typically affects those who are prone to aspiration of gastric contents, such as people with alcoholism. It is the most common cause of gram-negative pneumonia. Although a pulmonary embolus could also present with bloody sputum, her WBC count and the “jelly-like” texture of the sputum suggest Klebsiella infection
A 56-year-old male who had a kidney transplant 2 months ago is admitted with 1 week fever of 38° C and non-productive cough. In the ER, he developed respiratory distress and was intubated. Rapid flu swab was negative. Bronchoalveolar lavage was done and the attached photomicrograph reveals large nuclear inclusions within affected cells. What is the likely infection?
Cytomegalovirus.
In immunocompromised hosts, CMV can produce a severe interstitial pneumonitis. Pathologic findings include interstitial mononuclear inflammation and focal necrosis. It is identified by typical “owl-eye” inclusion bodies within affected cells.
what would a pulmonary infarct look like
extensive hemorrhage
A 70-year-old healthy, non-smoking male clinic patient is inquiring about vaccination for Pneumococcal pneumonia. What should he be told?
He should be vaccinated since he is over age 65.
It is recommended that all adults over the age of 65 receive pneumococcal vaccinations (there are currently 2 available, the 13 valent and the 23 valent). While there are approximately 90 serotypes and the vaccine does not cover all of them, it does offer protection against the most common serotypes and HAS been shown to reduce risk of pneumonia.
what are cefepime and meropenem
cefepime and meropenem are beta-lactam antibiotics
A 50-year-old man has a history of chronic alcoholism. He is found in a stuporous condition after 3 days of binge drinking. On physical examination, his temperature is 39.2°C. A few crackles are heard on auscultation of the right lung base. A chest x-ray shows a 3-cm lesion with an air-fluid level in the right lower lobe. He is intubated due to respiratory distress. Which of the following organisms are most likely to be detected in his bronchoalveolar lavage fluid?
Staphylococcus aureus.
This patient has a lung abscess that most likely resulted from aspiration, which can occur in persons with a depressed cough reflex or in neurologically impaired persons (e.g., due to acute alcoholism, anesthesia, or Alzheimer disease).
Three weeks after visiting her grandmother dying from a respiratory infection, a healthy 5-year-old girl develops a fever along with wheezing. On physical examination, her temperature is 38° C. Her lung fields are clear to auscultation, but there are expiratory wheezes. A chest x-ray reveals a solitary 2 cm peripheral mid-lung nodule and marked hilar lymphadenopathy. Laboratory studies show Hgb 13.6 g/dL, platelet count 183,600/microliter, and WBC count 5480/microliter. These findings are most consistent with infection by which of the following organisms?
The pattern of lung involvement is the classical ‘Ghon complex’ of primary tuberculosis, which is seen more commonly in children, though only about 5% of cases are symptomatic. The enlarged hilar nodes can impinge upon central airways to produce obstruction.
what is hepatization in pneumonia
As the immune/inflammatory response progresses, the lungs begin to take on the appearance of the liver (hepatization).
aspiration typically goes where in the lung
Aspiration into the right lung and the lower lobe is more common, because the mainstem bronchus to the left lung is more acutely angled.
when do you see reactive amyloid
pulmonary abcsesses
what are the arrows pointing to?
white arrow on left - hylum, healed primary TB
white arow head left - calcified ghon focus
white arrow right - calcified lymph nodes in hilum
white arrow head right - calcification in lung
A 38-year-old previously healthy woman presents to her primary care provider with a worsening non-productive cough and headache for the past 4 days. On physical examination her temperature is 38.3° C and lung exam is unremarkable. A chest x-ray shows patchy infiltrates and diffuse interstitial markings. Laboratory studies show a sputum gram stain with mixed flora. Her Hgb is 12.9 g/dL, platelet count 229,450/microliter, and WBC count 5,815/microliter. Following a course of azithromycin therapy, she improves, with no complications. Which of the following infectious agents is most likely to cause the pulmonary disease seen in this woman?
Mycoplasma pneumonia
when do you tyically see klebsiella
aspiration
where does legionella live
Legionella pneumophila lives in warm water and is often associated with hotels or large building complexes. Radiographically, features can be variable.
A 70-year-old, otherwise well man develops what he and his wife think is a mild upper respiratory tract infection. Four days later, he develops sweating, a temperature of 38.9° C, rapid breathing, coughing, and pain on breathing. A chest x-ray discloses consolidation of the lower lobe of his right lung. Which of the following is the most likely organism?
Streptococcus pneumonia.
Streptococcus pneumoniae is one of the most common bacteria to cause pneumonia, especially in the older adult. It is not unusual that it would occur after a viral illness, such as is described above.
A 60-year-old woman who immigrated from Mexico 5 years ago had been without regular medical care. She was a smoker and did have chronic respiratory symptoms. After she died at home, an autopsy was done. A photograph of her lung is attached. She most likely suffered from infection with which one of the following organisms?
Mycobacterium tuberculosis
The widespread destruction seen, with numerous cavities, could only be caused by Mycobacterium tuberculosis. Her history, coming from Mexico and “chronic respiratory symptoms” are suggesting of a chronic pulmonary infection
a necrotizing granuloma with central necrosis. TB.
what doe vancomysin cover
MRSA
what is this and when is it seen
Haemophilus influenza.
H. influenzae, a gram-negative coccobacillus, was previously a common cause of pneumonia in children. The incidence has decreased markedly since the introduction of vaccination for this organism. However, the unencapsulated form is still a common pathogen in those with chronic lung disease, such as COPD or cystic fibrosis.
What is this and what is it associated with
actinomyces israelii
sulphur granules
etiology of mycoplasma
Mycoplasma pneumoniae is a common etiology of pneumonia in young, healthy patients. Interestingly, it is spread by respiratory droplets so is contagious, in contrast with most bacterial forms of pneumonia.
A 46-year-old woman goes to the physician for a routine health maintenance examination. On physical examination, there are no remarkable findings. Her BMI is 22. She does not smoke. A tuberculin skin test is positive. A chest x-ray shows a solitary, 3-cm left upper lobe mass. The mass is removed at thoracotomy by wedge resection. The microscopic appearance of this lesion is depicted in the attached photomicrograph. Based on this information, which of the following is the most likely diagnosis?
mycobacterium TB
the picture shows pink, amourphous tissue at the lower left, representing caseous necrosis. The rim of the grnuloma has epithelioid cells and langhans giant cells. Caseating granulomatous inflammation is most typical of mycoplasma TB.
A 3-year-old boy is diagnosed with pneumococcal pneumonia after symptoms for a week. During the “gray hepatization” phase of acute pneumonia, what is the best description of the histologic appearance of lung?
Alveoli filled with neutrophils, bacteria, occasional RBCs, and fibrin
