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Pulmonary Board Review

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Title: Pulmonary Board Review


1
Pulmonary Board Review Lecture 1 Lisa M. Zahn,
MD Mount Sinai School of Medicine Department of
Emergency Medicine November 14, 2007
2
  • Lecture 1
  • Pneumonia community acquired, immunocompromised
    host, aspiration, pediatric
  • Pneumothorax
  • Mycobacterium tuberculosis
  • Miscellaneous Pleural effusion, lung abscess,
    ARDS, acute chest syndrome in Sickle Cell Anemia
  • Lecture 2
  • Asthma
  • COPD
  • Pulmonary Embolism
  • Fat Embolism
  • Cystic Fibrosis
  • Lung Cancer
  • Pediatric topics Croup, FB

3
  • Pneumonia

4
  • Which of the following statements regarding
    community-acquired pna is correct?
  • a) Positive blood cxs reflect the etiologic
    agent more accurately than do sputum cultures
  • b) Radiographic findings are often predictive of
    the infectious etiology
  • c) The incidence of positive blood cxs is higher
    in pna-specific severity index Class I than in
    Class V
  • d) The pna-specific severity index has been
    validated as a triage screening tool
  • e) Typical pna is differentiated from atypical
    pna by clinical presentation

5
  • Positive blood cxs reflect the etiologic agent
    more accurately than do sputum cultures.
  • Pneumonia Patient Outcomes Research Team (PORT)
    determined 20 statistically significant criteria
    that, when combined, yield a pna-specific
    severity index (PSI). PSI is further categorized
    into 5 classes with associated increasing
    mortalities. This information is further
    extrapolated for use in determining the need for
    hospital admission and type of bed (e.g., ICU).
    PORT findings were validated as a mortality
    prediction rule, not as a method for triaging pts
    with CAP.

6
  • The clinical utility of blood cxs in CAP pts
    with no comorbidities and lower PSI scores
    (Classes I-III) is low (6-11).
  • The clinical yield becomes higher (about 30) in
    pts with severe pna (PSI Class V).
  • Yield of sputum analysis is variable. Sputum cx
    and gram stain are best performed in high-risk
    hospitalized pts (e.g., intubated or ICU pts).
  • In contrast, positive blood cxs reflect the
    etiologic agent more accurately than sputum cxs.

7
  • The terms typical and atypical pna refer to
    the causative agent.
  • Typical refers to pna caused by pyogenic
    organisms (e.g, Streptococcus pneumoniae,
    Haemophilus influenzae)
  • Atypical refers to pna caused by Mycoplasma,
    Chlamydia, Legionella, viruses or rickettsiae.
  • Although CXR can provide a clue to the causative
    pathogen, the findings overall are nonspecific
    for accurately predicting a particular infectious
    etiology.

8
An important consideration regarding pna in
elderly pts, compared to younger patients is
that a) Elderly pts are less likely to have
pneumococcal bacteremia b) Elderly pts are less
likely to present in an advanced stage of
illness c) Elderly pts are less likely to present
with productive cough and fever d) Mycoplasma is
the most common atypical causative agent in
elderly pts e) Temperature higher than 38.3 c
(100.9 f) is more worrisome in younger pts
9
  • c) Elderly pts are less likely to present with
    productive cough and fever
  • Classic signs and symptoms of PNA, such as
    cough productive of purulent sputum, SOB, fever,
    are often absent in elderly or debilitated pts.
  • Initial presenting complaints can include acute
    confusion, weakness, tremulousness, and decline
    in functional status. Elderly pts are often
    sicker and in an advanced stage of illness in
    initial presentation (e.g., septic shock in
    absence of previous signs and symptoms).

10
  • As c/w younger adults, febrile (gt38.3 c) elderly
    pts with PNA are more likely to have serious
    bacterial infection. Pneumococcal bacteremia is
    3x more common in elderly pts than in younger pts
    with pna.
  • When c/w pts younger than 65, the mortality from
    pneumococcal pna is 3-5 times greater in the
    elderly (up to 40).
  • The most common atypical organism in the elderly
    is Legionella.
  • Mycoplasma pneumoniae is a common cause of CAP in
    healthy pts younger than 40.

11
  • Poor prognostic indicators for elderly pts with
    pna include hypothermia, temperature greater
    than 38.3 c (100.8 f), low WBC count,
    immunocompromise, Gram negative or staphylococcal
    infection, CV disease, bilateral infiltrates, and
    extrapulmonary disease.

12
  • A 75 year old NH pt with a PMH significant only
    for mild dementia choked on water while sitting
    at a table eating his lunch. He recovered
    uneventfully but was sent to the ED for
    evaluation of aspiration pna. He is in no
    respiratory distress and has nl VS, including
    pulse oximetry, an unremarkable PE, and a normal
    CXR. Which of the following considerations
    regarding his tx is correct?
  • a) Anaerobes have a major role in aspiration pna
  • b) Antibiotics should be initiated early
    regardless of whether he is symptomatic
  • c) Early initiation of corticosteroids will not
    help prevent lung injury
  • d) Expectorated sputum cxs will have high yield
    in identifying the causative organism
  • e) He is likely to have lung involvement in the
    superior segments of the lower lobes

13
  • c) Early initiation of corticosteroids will not
    help prevent lung injury.
  • Community-acquired aspiration PNA is caused by
  • Streptococcus pneumoniae
  • Staphylococcus aureus
  • Haemophilus influenzae
  • Enterobacteriaceae
  • Hospital-acquired aspiration PNA, in addition to
    the above is caused by gram-negative organisms
    (e.g., Pseudomonas aeruginosa)

14
  • If patient has a hx of chronic alcoholism, severe
    periodontal dz, putrid sputum, evidence of
    necrotizing pna or lung abscess on cxr consider
    Anaerobic organisms
  • The posterior segments of the upper lobes and the
    superior segments of the lower lobes are the most
    common sites of involvement, if aspiration
    occurred in a recumbent position.
  • The basal segments of the lower lobes, commonly
    RLL, are typically affected if the aspiration
    took place in an upright or semi-recumbent
    position.
  • Expectorated sputum cxs in aspiration PNA has
    low clinical utility secondary to OP
    colonization.
  • Corticosteroids in aspiration PNA have not been
    supported.
  • Prophylactic abx are not recommended in pts with
    an episode of an aspiration who have nl
    radiographic studies and no signs or symptoms of
    infection.

15
  • Which of the following organisms is the most
    common cause of pna in a pt with HIV infection
    and a CD4 count of 850 cells/microliter?
  • a) Cryptococcus neoformans
  • b) Mycobacterium tuberculosis
  • c) Pneumocystis jiroveci
  • d) Pseudomonas aeruginosa
  • e) Streptococcus pneumoniae

16
  • e) Streptococcus pneumoniae
  • The most common cause of bacterial pneumonia in
    pts with HIV is Streptococcus pneumoniae. C/w
    non-HIV positive pts, the incidence of
    streptococcal pna is 9 to 10 x higher in HIV pts,
    and is commonly associated with bacteremia.
    Bacterial infections are more likely to cause pna
    when the pts CD4 count is above 800
    cells/microliter.
  • Haemophilus influenzae and Pseudomonas aeruginosa
    are also common causes of bacterial pna in HIV
    pts. The incidence of Haemophilus influenzae is
    100 x higher in HIV pts than in non-HIV pts.

17
  • C/w other bacterial pathogens, Pseudomonas
    aeruginosa pna in HIV pts is more likely to cause
    lower WBC and CD4 counts.
  • CD4 counts between 250 and 500 cells/microliter
    increase the risk of infection by Mycobacterium
    tuberculosis
  • Cryptococcus neoformans
  • Histoplasma capsulatum
  • CD4 count below 200 cells/microliter increase
    the risk of infection by Pneumocystis jiroveci
    (formerly Pneumocystis carinii)

18
  • Bacterial pna, TB and opportunistic infections
    can result in pulmonary nodules in HIV pts.
  • Pleural effusions are also common in HIV pts and
    are often caused by Streptococcus pneumoniae and
    Staphylococcus aureus.
  • Common noninfectious etiologies of pleural
    effusions in HIV pts include NHL, Kaposi sarcoma
    and adenocarcinoma of the lung.

19
  • A 48 year old man presents complaining of SOB,
    cough, and fever. His pulse oximetry reading is
    92 on room air CXR demonstrates a RLL
    infiltrate. He underwent right lung
    transplantation 4 weeks earlier for idiopathic
    pulmonary fibrosis. Which of the following
    statements regarding the pts condition is
    correct?
  • a) Acute rejection can be differentiated
    clinically from infection
  • b) Bacterial pna is a common complication during
    the early post-op period
  • c) EBV is the most common viral infection after
    lung tx
  • d) Prophylaxis against pneumocystis jiroveci
    should be initiated only in lung tx pts who have
    HIV infection
  • e) Steroids are contraindicated for the
    management of acute rejection

20
  • Bacterial pna is a common complication during the
    early post-op period.
  • Lung transplantation is most commonly performed
    for COPD, idiopathic pulmonary fibrosis, CF,
    alpha1-antitrypsin deficiency emphysema, primary
    pulmonary htn, sarcoidosis and bronchiectasis.
  • Absolute exclusion criteria for lung
    transplantation are HIV infection, noncurable
    malignancy, active cigarette smoking, chronic HBV
    or HCV, and nontreatable infections.
  • Secondary to the use of various immunosuppressive
    agents, lung tx pts are at a higher risk for both
    opportunistic and non-opportunistic infections.
  • Prophylaxis against Pneumocystis jiroveci
    (formerly Pneumocystis carinii) with bactrim is
    customary after lung tx.

21
  • Acute rejection and infection are common
    complications during the first post-op year.
    Distinguishing between the two is difficult
    because of overlap between the signs and
    symptoms.
  • Dx requires bronchoscopy and transbronchial bx.
    High- dose steroids is the tx for acute
    rejection.
  • Bacterial pna is a common complication during
    the early post-op period, especially the first 3
    months.
  • Among viral agents, CMV is the most common
    pathogen (within the first post-op year). Other
    viral infections (e.g., EBV, HSV) are less
    common, but possible as well.
  • Among fungi, Aspergillus species can be
    associated with invasive disease.

22
  • For previously healthy children with community
    acquired pneumonia, which of the following
    statement is correct?
  • a) Age is the most important factor in selecting
    empiric antibiotic therapy
  • b) Concurrent presence of watery diarrhea
    reliably identifies a viral etiology
  • c) Localized chest pain is most commonly
    associated with viral pna
  • d) Viral and bacterial pneumonia can reliably be
    differentiated in infants
  • e) Wheezing in preschool-aged children is
    pathognomonic for viral pna

23
  • Age is the most important factor in selecting
    empiric antibiotic therapy
  • The organisms associated with CAP in previously
    healthy children differ by age.
  • Perinatally acquired organisms (GBS, gram
    negative enteric bacteria) have been identified
    as the etiologic agents in the first 3 weeks of
    life, only. Infants of this age are admitted and
    administered ampicillin and gentamicin with or
    without cefotaxime. Other organisms in this age
    group include CMV, Listeria monocytogenes.

24
  • In infants 3 weeks to 3 months organisms include
    Chlamydia trachomatis, RSV, Parainfluenza 3,
    Streptococcus pneumoniae, Bordetella Pertussis
    (more likely to cause bronchitis), and less
    commonly Staphylococcus aureus.
  • Afebrile infants between 3 weeks and 3 months old
    with normal oxygen saturation, an oral macrolide
    such as erythromycin or azithromycin is
    recommended.
  • Afebrile infants between 3 weeks and 3 months old
    with hypoxia, hospital admission for IV
    erythromycin is recommended.
  • Febrile infants between 3 weeks and 3 months old,
    admission to the hospital for IV cefotaxime is
    recommended.

25
  • Infants and children between 4 months and 4 years
    old, the recommended outpt tx is oral
    amoxicillin.
  • Although, most commonly pna is caused by RSV,
    parainfluenza virus, influenza virus, adenovirus,
    rhinovirus.
  • If inpatient tx is indicated, (e.g., signs of
    sepsis, alveolar infiltrates, or large pleural
    effusions) IV amp or IV cefotaxime or cefuroxime.
    Bacterial organisms include Streptococcus
    pneumoniae, Haemophilus influenzae, Mycoplasma
    pneumoniae (although more common in the older
    children) and TB (in certain populations).

26
  • In children 5 to 15 years old, Mycoplasma
    pneumoniae is the chief cause of pna. Although
    Chlamydia pneumoniae is possible. Streptococcus
    pneumoniae is more likely for a lobar pna, and TB
    should be considered in certain populations.
  • Children 5 to 15 years old treated as outpts,
    oral erythromycin, azithromycin, or
    clarithromycin is recommended.
  • Children 5 to15 years old who do not have lobar
    or lobular infiltrates or pleural effusions but
    are ill enough to be admitted, IV erythromycin or
    IV azithromycin is recommended.
  • For children older than 8 years, oral or IV
    doxycycline may be substituted for macrolide inpt
    or outpt therapy.
  • Children 5 to 15 years old who require hospital
    admission, i.e., with signs of sepsis, an
    alveolar infiltrate, or a large pleural effusion,
    IV cefotaxime or cefuroxime is recommended.

27
  • Localized chest pain is most commonly associated
    with bacterial pna.
  • Other factors, such as concurrent OM, rhinorrhea,
    sick contacts, myalgias, diarrhea, do not
    reliably differentiate bacterial vs viral pnas.
  • Although wheezing is more commonly seen with
    viral pna than with bacterial pna, wheezing is
    not pathognomonic for viral pna. In studies that
    directly examined this, wheezing was seen in 435
    to 56 of viral pna cases and in 16 of bacterial
    pna cases.

28
  • Pneumothorax

29
  • Which of the following conditions is most likely
    to be a precipitating factor for PTX?
  • a) COPD
  • b) Cigarette smoking
  • c) Marfan syndrome
  • d) Physical exertion
  • e) Pneumocystis carinii pna

30
  • Cigarette smoking
  • PTX occurs when air enters the intrapleural space
    (i.e., space between the visceral and parietal
    pleura).
  • Tension PTX is caused by positive pressure in the
    pleural space leading to decreased venous return,
    hypotension, hypoxia.
  • PTX is classified into
  • iatrogenic/traumatic
  • spontaneous primary or secondary

31
  • Iatrogenic/traumatic PTX
  • secondary to invasive procedures such as needle
    bx of the lung (50)
  • subclavian line placement (25)
  • NGT placement
  • positive pressure ventilation
  • other trauma
  • Primary spontaneous PTX
  • accounts for the majority of pneumothoraces
  • no underlying lung disease
  • male smokers of taller than average height
  • relative risk is 6x higher in men than women
  • cigarette smoking confers a greater than 201
    relative risk c/w non-smokers
  • other risk factors changes in ambient
    atmospheric pressure, MVP, Marfan syndrome
  • physical exertion is not a factor

32
  • Secondary spontaneous PTX
  • 1/3 of spontaneous PTX
  • underlying pulmonary disease
  • COPD is the most common associated condition
  • other associated lung disease asthma, CF,
    necrotizing bacterial PNA, lung abscess, PCP PNA,
    TB, sarcoidosis, primary lung cancers,
    pulmonary/pleural mets.
  • Catamenial PTX
  • rare cause of recurrent spontaneous PTX
  • occurs in association with menses
  • develops within 72 hours of onset of menses

33
  • Clinical features of PTX
  • symptoms are directly related to the size, rate
    of development and underlying lung disease
  • acute onset of pleuritic pain is found in 95
  • dyspnea occurs in 80 and predicts a large PTX
  • decreased breath sounds on the affected side are
    present 85 of the time
  • only 5 have tachypnea over 24 breaths per minute
  • EKG changes, including ST changes and T-wave
    inversion may be seen with PTX
  • Diagnosis
  • CXR upright PA is 83 sensitive
  • expiratory films may slightly enhance
    visualization
  • CT scan may be more sensitive
  • recent studies have shown the sensitivity of US
    to be near 100

34
  • A 22 year-old college basketball player presents
    with sudden-onset SOB. Chest radiography reveals
    a 10 ptx. The pt has not had a prior episode of
    ptx. He is not in acute distress, and VS and
    oxygen saturation are wnl. w/o any intervention,
    approximately how long will it take for the ptx
    to resolve on its own?
  • a) 12 hours
  • b) 24 hours
  • c) 36 hours
  • d) 1 week
  • e) 3 weeks

35
  • 1 week
  • Management of PTX
  • If unstable (e.g., suspected tension ptx) place
    chest tube prior to CXR.
  • Observation is acceptable approach for a healthy,
    young pt, with a small (i.e., lt20 of hemithorax)
    primary spontaneous PTX. Observe x 6 hours, may
    repeat cxr and d/c with surgical f/u if no
    enlargement on cxr. However, 23 to 40 of
    patients will eventually require tube
    thoracostomy. Aspiration is another option for
    small asymptomatic pneumothoraces.
  • Intrinsic reabsorption rate in intrapleural air
    is approximately 1 to 2 of lung volume qd.

36
  • Administration of 100 O2 increases the
    reabsorption rate by 3 to 4 fold. Mechanism is by
    lowering the alveolar partial pressure of
    nitrogen. As a result, the rate at which air
    diffuses across the pleural-alveolar barrier is
    accelerated.
  • When dischargeable, pts should be instructed to
    avoid air travel or underwater diving until the
    PTX has completely resolved.
  • Management of secondary spontaneous PTX is
    usually managed by tube thoracostomy, because
    less invasive approaches such as observation or
    aspiration has a much lower success rate.

37
  • Mycobacterium tuberculosis

38
  • Which of the following conditions places a
    patient at higher risk for the progression of TB
    from latent infection to active disease?
  • a) Asthma
  • b) CHF
  • c) DM
  • d) Influenza
  • e) Smoking

39
  • Risk factors for developing active TB in a
    previously infected pt include
  • HIV
  • Other immunosuppressive conditions (i.e.,
    steroids, s/p organ tx)
  • TB infection within the last 2 years
  • CXR suggestive of prior TB in an untreated
    person
  • IVDA
  • DM
  • Silicosis
  • Head and neck CA
  • Hematologic and reticuloendothelial disease
  • CRF
  • Low body weight (lt10 of ideal body weight)

40
  • Risk factors for acquiring TB
  • Close contact with a person known to have active
    TB
  • HIV infection
  • Homelessness
  • Incarceration
  • Alcoholism
  • Occupational exposure (e.g., in hospitals,
    nursing homes)
  • Advanced age
  • IVDA
  • Immigration from areas with higher rates of TB
    Asia, Africa, Latin America

41
  • General Information
  • TB is a major global problem. More than 30 of
    the worlds population has latent or active TB.
  • TB causes 2 million deaths yearly.
  • TB rates remain disproportionately high in
    foreign-born persons, accounting for ½ of all US
    cases.
  • Pathophysiology
  • TB is caused by Mycobacterium tuberculosis, a
    slowing growing aerobic rod, multilayered cell
    wall which account for its acid-fast property.
  • Transmission occurs through inhalation of droplet
    nuclei in to the lungs.
  • Hematogenous dissemination may occur. Organism
    survives in areas of high oxygen content or blood
    flow apical and posterior segments of the upper
    lobe, superior segments of lower lobe, renal
    cortex, meninges, epiphyses of long bones,
    vertebrae.
  • Latent TB infections are asymptomatic with
    positive PPD.
  • Latent TB will progress to active disease in 5
    of cases, within the first 2 years of infection.
    An additional 5 will reactivate over their
    lifetime.
  • Reactivation rates are higher at extremes of age,
    pts with recent primary infection, immune
    deficiency (most notably HIV), and pts with
    chronic diseases (e.g., DM, renal failure)

42
  • Clinical Features
  • Primary TB infection is usually asymptomatic.
    (Usually noted with a positive PPD.)
  • Some pts may present with active pneumonitis or
    extrapulmonary disease.
  • Immunocompromised pts are more likely to develop
    rapidly progressive primary infections.
  • Reactivation of latent TB accounts for most
    active cases.
  • Active TB presents subacutely with fever, cough,
    weight loss, fatigue, night sweats. Hemopytsis,
    pleuritic chest pain and dyspnea may develop.
  • The pulmonary physical exam is usually
    non-diagnostic, but rales or rhonchi may be
    present.

43
  • Extrapulmonary TB develops in 15 of cases. The
    most common form is lymphadenitis.
  • Also, pleural effusion or pericarditis may occur.
  • TB peritonitis presents insidiously after
    extension from local lymph nodes.
  • TB meningitis can occur from hematogenous spread.
    With symptoms of fever, HA, meningeal signs,
    and/or CN deficits.
  • Miliary TB is a multisystem disease caused by
    massive hematogenous spread. Most common in
    immunocompromised pts and children. P/w fever,
    cough, weight loss, adenopathy, HSM, cytopenias.
  • Prior partially treated TB is a rf for
    drug-resistant TB.
  • Multi-drug resistant TB is more common in HIV pts
    than in the general population, and has a higher
    fatality rate.

44
  • Diagnosis
  • CXR are the most useful diagnostic tool for
    active TB in the ED.
  • Active primary TB presents with parenchymal
    infiltrates in any lung area.
  • Hilar and/or mediastinal adenopathy may occur
    with or without infiltrates. Lesions may calcify.
  • Reactivation TB presents with lesions in the
    upper lobes or superior segments of the lower
    lobes. Cavitation, calcification, scarring,
    atelectasis and effusions may be seen.
  • Cavitation is associated with increased
    infectivity.

45
  • Miliary TB may cause diffuse small (1 to 3 mm)
    nodular infiltrates.
  • Pts coinfected with HIV and TB are particularly
    likely to have atypical or nl cxr
  • Acid fast staining of sputum can detect
    mycobacteria in 60 of pts with pulmonary TB
    (lower yield in HIV pts). Therefore a single
    sample may yield a false negative. Atypical
    mycobacteria can yield false positives.
  • PPD tests identifies latent, prior, or active TB
    infection. Results read within 48 to 72 hours.
    Pts with positive PPD and no active TB disease
    should be evaluated for prophylactic treatment
    with INH to prevent reactivation TB.
  • Immunosuppresed pts may yield false-negative
    results to PPD even if not fully anergic.

46
  • Emergency department care and disposition
  • Initial therapy includes a 4 drug regimen, until
    susceptibilities are available. (e.g., INH,
    rifampin, pyrazinamide, and streptomycin or
    ethambutol x 2 months). Then at least 2 drugs are
    continued for four more months.
  • Admission for clinical instability, dx
    uncertainty, unreliable outpt f/u or compliance,
    and active known MDR TB.
  • Admit to respiratory/droplet isolation.
  • ED staff should receive regular PPD skin testing.

47
Miscellaneous
48
Which of the following statements regarding
pleural effusions is correct?
  • a) A common cause of atraumatic hemothorax is SLE
  • b) A pH of less than 7.3 strongly suggests
    pleural empyema or esophageal rupture
  • c) Effusions associated with PE are transudative
  • d) Management of complicated parapnuemonic
    effusions includes tube thoracostomy
  • e) The most common cause in developing countries
    is CHF

49
Management of complicated parapnuemonic effusions
includes tube thoracostomy.
  • Parapneumonic effusion is a pleural effusion
    associated with bacterial pna, bronchiectasis or
    lung abscess.
  • A complicated parapneumonic effusion requires a
    tube thoracostomy, in addition to abx.
  • Most common cause of pleural effusions in
    developed countries is CHF.
  • Other causes of pleural effusions malignancy,
    bacterial PNA, PE
  • In developing countries, TB is the leading cause
    of pleural effusion.

50
  • Pleural effusions exudative or transudative.
  • Exudative inflammatory or neoplastic conditions,
    high protein content
  • Transudative CHF, Nephrotic syndrome low
    protein content. Form from imbalance in
    hydrostatic or oncotic pressures across the
    pleural membrane.
  • PE or sarcoidosis can cause either exudative or
    transudative effusions.

51
  • Bloody pleural effusions can be from trauma,
    malignancy, pulmonary infarction.
  • Hemothorax defined when the hematocrit of the
    pleural fluid is more than 50 of the peripheral
    blood.
  • Trauma can cause hemothorax. Other causes include
    rupture of tumor or blood vessel (ruptured aortic
    aneurysm).
  • Parapneumonic effusions, malignancies, rheumatoid
    effusions, TB and systemic acidosis are
    associated with a pleural fluid pH of less than
    7.3,
  • A pH of less than 7 suggests empyema or
    esophageal rupture.

52
Which of the following statements regarding lung
abscess is correct?
  • a) A cancerous etiology is more likely if the
    abscess develops in the posterior portion of the
    lung
  • b) Anaerobic bacteria are more commonly found in
    immunocompromised pts than in immunocompetent pts
  • c) In most cases, the abscess cavity communicates
    with a bronchiole
  • d) Infectious lung abscesses commonly occur in
    the superior segments of the lower lobes
  • e) Surgical intervention is commonly necessary

53
  • In most cases, the abscess cavity communicates
    with a bronchiole
  • Etiology of lung abscess includes
  • Infectious i.e., bacterial, fungal, parasitic
  • Neoplastic
  • Inflammatory
  • Infectious etiology, most commonly anaerobic
    bacteria. However in immunocompromised pts,
    aerobic bacteria such as Staphylococcus aureus,
    Escherichia coli, Klebsiella pneumoniae and
    Haemophilus influenzae have been implicated.
  • Pts who have conditions that predispose to
    aspiration, such as stroke or seizure area at
    higher risk for developing lung abscess.

54
  • Basal segments of the lower lobes and the
    posterior segments of the upper lobes are common
    locations for infectious lung abscesses.
  • Cancerous etiology should be suspected when the
    abscess is located in the anterior portion of the
    lung.
  • Frequently, pts with lung abscesses have a
    prolonged (more than 2 week) course of
    symptomatology. Clinical features include cough,
    fever, chest pain.
  • Hemoptysis is seen in up to 25 of cases
  • In 75 of cases, the abscess cavity communicates
    with a bronchiole. CXR will show a cavitary
    lesion with an air-fluid level.
  • 85 to 90 of pts with bacterial lung abscess can
    be successfully treated with broad-spectrum abx
    alone. Surgical intervention is rarely required.

55
Which of the following statements regarding
mediastinal disorders is correct?
  • a) Barium studies of the GI tract are not useful
    for evaluating posterior mediastinal lesions
  • b) Hamman crunch is best heard with the pt in the
    left lateral recumbent position
  • c) Median sternotomy for cardiac surgery is a
    common cause of chronic mediastinitis
  • d) The phrenic nerve is located within the
    anterior mediastinum
  • e) TB is a common cause of acute mediastinitis

56
  • Hamman crunch is best heard with the pt in the
    left lateral recumbent position
  • Mediastinum is divided into 3 compartments
  • Anterior from the sternum to the pericardium and
    brachiocephalic vessels. It contains the thymus
    and internal mammary arteries and veins. Common
    lesions include thymomas, lymphomas, teratomatous
    neoplasms, and thyroid masses.
  • Middle contains the heart, ascending and
    transverse aortic arches, vena cava,
    brachiocephalic vessels, phrenic nerves, trachea
    and main bronchi, pulmonary arteries and veins.
    Common lesions include vascular masses,
    lymphadenopathies from metastases or
    granulomatous diseases, and pleuropericardial and
    bronchogenic cysts.

57
  • Posterior lies between the pericardium
    anteriorly and the vertebral column posteriorly.
    It contains the descending thoracic aorta,
    esophagus, thoracic duct, azygous and hemiazygous
    veins. Common lesions include neurogenic tumors,
    meningoceles, meningomyeloceles, gastroenteric
    cysts, and esophageal diverticula.

58
  • CT scanning is the dx imaging test of choice.
    But, for some conditions found in the posterior
    mediastinal compartment (e.g., hernias,
    esophageal diverticula) barium studies of the GI
    tract may be better.
  • Acute mediastinitis may be caused by esophageal
    perforation or after median sternotomy after
    cardiac surgery.
  • Chronic mediastinits is often due to TB or
    histoplasmosis. Sarcoidosis and silicosis are
    possibilities as well.
  • The Hamman sign, or crunch, is a physical finding
    associated with pneumomediastinum and or
    pneumopericardium. It is a crunching noise
    synchronous with the heartbeat, and it is best
    hear when the patient is in the left lateral
    recumbent position.

59
Which of the following statements regarding acute
respiratory distress syndrome is correct?
  • a) Advanced age is not a risk factor
  • b) CXR often reveals a unilateral focal
    infiltrate
  • c) Early use of corticosteroids reduces mortality
  • d) It is a cardiogenic pulmonary syndrome
  • e) It might be associated with the use of
    amiodarone

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  • It might be associated with the use of amiodarone
  • ARDS is a form of noncardiogenic pulmonary edema.
  • The most common causes include
  • Sepsis
  • Trauma
  • Burns
  • Multiple transfusions
  • Aspiration of gastric contents
  • Drug overdose (e.g., salicylates, opiates)

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  • Other drugs that have been reported to be
    associated with ARDS include TCAs,
    cyclosporine, amiodarone, HCTZ, chemotherapeutic
    agents (e.g., bleomycin).
  • Among infections, bacterial PNA is a common
    cause.
  • Other conditions associated with ARDS include
    toxic gas or smoke inhalation, near-drowning,
    radiation injury, pancreatitis, embolism,
    eclampsia, SAH, DIC, high-altitude exposure,
    oxygen toxicity, and cardiopulmonary bypass.
  • The ratio of arterial partial pressure of oxygen
    (Pao2) over inspiratory oxygen fraction (FIo2)
    less than 200 mm Hg is a feature of ARDS.
  • Age greater than 75 years, chronic alcohol abuse,
    metabolic acidosis, and presence of more than on
    predisposing condition (e.g., head trauma and
    sepsis) increase the risk of developing ARDS.

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  • Pts. who develop ARDS from direct lung injury
    (e.g., pna, pulmonary contusion) have a lower
    mortality rate than those who develop ARDS from
    indirect lung injury (e.g., drug overdose,
    pancreatitis).
  • CXR show bilateral, diffuse, patchy or
    homogeneous alveolar or interstitial infiltrates
    involving at least ¾ of the lung fields.
  • Unlike cardiogenic pulmonary edema, cardiomegaly
    and pleural effusions are not commonly seen with
    ARDS.
  • Mechanical ventilation should be initiated with
    low tidal volumes (6 ml/kg predicted body
    weight).
  • To date, there is no evidence that
    corticosteroids reduce mortality when used in
    early ARDS.
  • Reducing left atrial filling pressures, with
    fluid restriction and diuretics, is an important
    part of ARDS management.

63
  • A 26 year old man with sickle cell disease
    presents with atypical vaso-occlusive type arm
    and leg pain. He also reports dull right-side
    chest pain, a nonproductive cough and fever to 39
    c (102.2 f). Diagnostic testing reveals an acute
    RLL infiltrate on CXR, WBC count of 15.2, Hgb
    8.6, platelet count of 112, 000. The next most
    appropriate management step is
  • a) Admit the pt, begin broad-spectrum abx and
    bronchodilators, ensure oxygenation, address
    pain control, consider transfusion
  • b) Admit the pt for IV hydration and pain
    control, and await the results of blood and
    sputum cxs to guide appropriate abx therapy
  • c) D/c the pt on a macrolide abx and oral pain
    medication with 24-hour follow-up
  • d) Initiate bronchodilators if the pt has audible
    wheezing or a peak expiratory flow rate less
    than 50 of predicted, and base disposition
    decision on the response to bronchodilatory
    therapy
  • e) Order a spiral CT scan of the chest to
    evaluate for the presence of PE

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  • Admit the pt, begin broad-spectrum abx and
    bronchodilators, ensure oxygenation, address pain
    control, consider transfusion
  • Acute chest syndrome is the leading cause of
    death and hospitalization in SCA pts.
  • Acute chest syndrome is defined by chest pain,
    fever greater than 38.5 c, tachypnea.
  • Wheeze or cough along with a new pulmonary
    infiltrate involving at least one complete lung
    segment.
  • Half of the pts in Vichinskys study were
    admitted with a diagnosis other than acute chest
    syndrome, typically vaso-occlusive crisis.
  • Consider vaso-occlusive symptoms as a prodrome of
    acute chest syndrome.
  • Pts older than 20 were more likely to experience
    neurologic complications and death from
    respiratory failure.
  • A platelet count less than 200, 000 was an
    independent predictor of neurologic complications.

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  • The leading causes of acute chest syndrome were
  • Pulmonary infections 29 (e.g., Chlamydia
    pneumoniae and Mycoplasma pneumoniae)
  • Pulmonary infarctions 16
  • Fat emboli 9 (diagnosed by bronchoscopic bx)
  • Treatment is supportive, and include admission,
    supplemental O2, aggressive airway management,
    hydration, pain control, broad spectrum abx
    (including a macrolide), empiric bronchodilators,
    and transfusions.

66
  • Thank you for your attention.
  • Questions?
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