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.
(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).
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 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 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 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
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.
