Pumerantz-Respiratory Infection Cases

Front 1

A 53-year-old woman presents to the ED with 3 days of fever, progressively worsening sore throat, and dyspnea. She states the sore throat began several hours after eating a whole steamed fish and rice, and believes she swallowed a fish bone that became “stuck” in her throat. She has a 40-pack-year history of cigarette smoking. On exam, she is febrile, appears ill and anxious, sitting upright and drooling. There is audible stridor but no audible wheezes. Her anterior neck is tender to palpation. The emergency physician is concerned about a possible foreign-body in the upper esophagus and obtains a lateral neck x-ray.

Back 1

Epiglottitis-H. flu

Front 2

What are important signs and symptoms that indicates epiglottitis?

Back 2

Progressively worsening sore throat (gets better in most diseases)
Thumb print sign on lateral neck x-ray
swollen, cherry red epiglottis on laryngoscopic view
blood cultures (perform when symptoms are severe)

Front 3

What bugs cause epiglottitis?

Back 3

1. non-typeable Hamophilus influenza; big increase in recent years (especially in elderly populations)
2. Group A strep

Front 4

Describe the empirical treatment of epiglottitis

Back 4

1. Admit to hospital due to airway obstruction
2. H. flu resistant to penicillin and ampicillin due to B-lactamase
a. use combo ampillicin sulbactam-inhibits B-lactamase
b. use ceftriaxone (3G cephalosporin)
*give drugs IV*

Front 5

A 25-year-old man presents to his primary care physician’s office with complaints of cough minimally productive of whitish phlegm, headache, mild sore throat, dyspnea, and low-grade fever that has persisted over the past 5 days. He has a history of asthma as a child and has never smoked. He states he got a flu shot a month ago. His 5-year-old daughter just got over a “cold.” On exam, he appears moderately ill and has audible wheezes but no stridor. Respiratory rate is 20 and there is a prolonged expiratory phase. Neck is supple, nontender, and without masses or adenopathy. Lungs have decreased breath sounds at the bases, scattered wheezes and rhonchi, but no rales or egophony. A chest x-ray is obtained

Back 5

bronchitis

Front 6

How do you differentiate bronchitis from epiglottitis and pneumonia?

Back 6

1. lower respiratory infection (differs from epiglottitis)
2. no rales or egophony (no consolidation present-no pneumonia)
3. normal appearing chest x-ray (pneumonia shows up quickly)
4. doesn't involve parenchyma (pneumonia does)

Front 7

What is the pathogenesis of bronchitis?

Back 7

infection leads to narrowed airway and inflamed bronchial tube lining caused by cilia immersed in thickened mucus
note-either viral or M. pneumonia bronchitis can exacerbate asthma (especially if history as child)

Front 8

List diseases of the upper and lower respiratory tracts

Back 8

A. upper-rhinitis (common cold); pharyngitis; laryngitis
B. lower-tracheitis; bronchitis; bronchiolitis; bronchopneumonia

Front 9

Differentiate b/t the bugs that cause bronchitis

Back 9

1. Viral (70%); hard to pinpoint which one (influenza common)
2. Mycoplasma pneumonia-
causes inflammation and coughing (bronchospastic); higher rate of fever (except influenza), patient looks sicker
note-can’t distinguish M. pneumonia from viral bronchitis by cough or sputum production

Front 10

Describe the treatment of bronchitis

Back 10

1. Supportive for viral symptoms-fluid, rest; probably not antimicrobials-since underlying disease is asthma; if no better in 3 weeks, still coughing-asthma treatments (ICs)
2. suspicion of M. pneumonia or chlamydial infection-use Azithromycin (macrolide)

Front 11

A 70-year-old man is brought to the ED after developing sudden-onset of fever, chills, rhinorrhea, sore throat, generalized malaise, myalgias, and headache. Within hours, he develops a non-productive cough and dyspnea. He has a history of coronary artery disease, CHF, and diabetes mellitus. He reports getting a flu shot one week ago. He received pneumococcal immunization at age 65. He denies alcohol or tobacco use. On exam, he appears moderately ill. Temperature is 39°C; pulse is 100 and regular; respiratory rate is 20; BP is 110/60. Cardiac exam reveals an S3 and JVD but no murmurs or rubs. Lungs reveal scattered rhonchi, wheezes, and bibasilar crackles. A chest x-ray is obtained

Back 11

influenza (H1N1)

Front 12

What important virulence factors does influenza contain?

Back 12

Hemagglutinin-virial attachment to host
neuraminidase (Sialidase)-virion release

Front 13

What are the common signs and symptoms of influenza?

Back 13

*classic presentation that is easy to misdiagnose*
1. Fever (negative predictor for rhinovirus)
2. cough
3. sore throat (severe sore throat suggests streptococcal disease)
4. diarrhea and vomiting (poorer prognosis)
5. Nasal congestion/tracheal tenderness
6. hair hurts
*More subtle symptoms in elderly*

Front 14

Describe the pathological and histological changes associated w/ H1N1 influenza

Back 14

Evidence of ongoing aberrant immune response; pathological changes localized to the lung
1. Diffuse alveolar disease (DAD) w/ instense alveolar hemorrhage
2. Necrotizing bronchiolitis

Front 15

Describe prognosis of H1N1

Back 15

Persons born before 1930 have highest titers of neutralizing antibody to 2009 H1N1
Exposure to 1918 H1N1-like virus contributes to cross-reactive Ab response to 2009 H1N1

Front 16

Describe the diagnostic tests used to test for influenza

Back 16

1. PCR-results same day, good sensitivity and positive predictive value (Test of choice)
2. Rapid Ag assay (nasopharyngeal swab)-Immediate results; high positive predictive value, but low sensitivity)
3. Direct fluorescent Ab-similar results to rapid Ag assay (quick result, high positive predictive value, low sensitivity)
4. Culture-older test, good but is being phased out (takes awhile to get results)

Front 17

Describe genetic reservoirs and intermixing

Back 17

animals (pigs and birds) and people living in close contact w/ one another (Asian countries)
antigenic shift-genetic reassortment (can cause pandemics)

Front 18

Describe influenza vaccines

Back 18

targets viruses that show up in Asia and Australia; tries to predict which viruses will circulate throughout the world; needs to be changed each year due to antigenic drift (minimal mutations)
doesn’t lower chance of getting the flue (especially in first few weeks), but decreases risk of dying and passing to others

Front 19

Discuss prenvention measures regarding influenza

Back 19

A. healthcare settings-Aerosol generating procedures (e.g. aspiration, intubation) are associated with increased risk of infection transmission; use particulate respirator,
eye protection, long-sleeved gown, gloves
B. Well individuals-personal hygeine, reduce time spent in a crowd, improve ventilation in living space
C. symptomatic individuals-stay home, keep your distance, personal hygiene, improve living ventilation

Front 20

Describe the treatment for influenza A and B

Back 20

Neuraminidase inhibitors (inhibit virion release)-Oseltamivir and zanamivir (inhaled); give early (right away)-response is dramatic improvement; if this response is seen, confirms influenza diagnosis
note-oseltamivir is better because zanamivir can be coughed out of airways

Front 21

Describe bacterial complications associated w/ influenza

Back 21

Fever beyond 3-5 days or new symptoms indicate bacterial complication
1. acute bronchitis (most common)
2. pneumonia (concurrent or post-influenza)-caused by S. pneumonia (most common), S. aureus, or H. flu
3. sinusitis
4. meningitis

Front 22

Describe secondary bacterial pneumonia associated w/ influenza

Back 22

the lung looks like a liver (filled w/ fluid)
can contain Pfeiffer’s bacillus (H. flu)

Front 23

A 60-year-old woman with diabetes mellitus and coronary artery disease presents to the emergency department with sudden-onset of fever, productive cough, dyspnea, and malaise. She was last hospitalized 2 years ago when she underwent 3-vessel coronary artery bypass graft surgery. She denies any known drug allergies. On exam, she is ill-appearing and disoriented to place and time; temperature is 39°C; BP is 100/60; pulse is regular@120/min; respiratory rate is 33/min. There is dullness to percussion, increased tactile fremitus, coarse rales and bronchial breath sounds at the right base. WBC count is 15,000 with 20% bands. Blood urea nitrogen is 25 mg/dL. Chest radiograph is shown

Back 23

Community acquired pneumonia (CAP)-Streptococcus pneumonia

Front 24

What signs and symptoms point to pneumonia?

Back 24

patient knows the exact moment they got sick
chest x-ray shows consolidation in lung

Front 25

Describe the diagnostic tests used to identify S. pneumonia

Back 25

1. blood culture (definitive diagnosis)-only 20% of patients have positive blood cultures, but very sick subset is much higher
2. Sputum culture-not great test (pontentially unreliable); must get sputum from lungs not contaminated by oral mucosa (if negative, can’t rule out CAP)
alveolar macrophages indicate you got to right level; shows gram positive diplococci (lancet shaped)
3. Flourescent (FA) stain-shows capsule

Front 26

Describe the virulence factors and pathology of S. pneumonia

Back 26

A. major virulence factor is antiphagocytic capsule (resists alveolar macrophages); S. pneumonia is not pathogenic w/out capsule
B. Pathology-lobar pneumonia; Air replaced w/ fluid; red hepatization (Intra-alveolar polymorphonuclear exudate) initially followed by grey hepatization (fibrinosuppurative exudate)

Front 27

Describe the microbiology of S. pneumonia

Back 27

1. Alpha hemolytic
2. grows on sheep blood auger
3. optochin sensitive
4. bile sensitive

Front 28

Describe the CURB-65 criteria, categorization, and treatment options for pneumonia

Back 28

Confusion
Urea >7mmol/l
Respiratory rate >30
Blood pressure <90/60
Age->65 years
Group 1: score of 0-1 (low mortality)-home treatment
Group 2: score of 2 (intermediate mortality)-consider hospitalization (inpatient or outpatient supervision)
Group 3: score of 3 or more (high mortality)-manage in hospital as severe pneumonia (assess for ICU admission with higher scores)

Front 29

Describe the treatment of S. pneumonia

Back 29

Beta lactams-ampicillin can overcome penicillin resistance; cephalosporin is good too
note-moving away from FQs

Front 30

Describe how you would assess nonresponders to treatment for S. pneumonia

Back 30

1. Wrong diagnosis
2. Wrong organism: consider Legionella pneumophilia- use point of care test (urine Ag); most patients w/ Legionella have type 1
3. Complication

Front 31

An 80-year-old female with NYHA Class IV CHF is transferred from a long-term care facility to the emergency department for new-onset fever and marked increase in sputum production. She has no known drug allergies. Review of the patient’s records provided by the facility indicates the patient had been on consecutive courses of ciprofloxacin and ceftazidime over the past 2 months for purulent tracheobronchitis. On exam, temperature is 38.6°C; respiratory rate is 30/minute and BP is 100/50. Lungs have scattered rhonchi and rales over the right hemithorax. A chest radiograph is shown

Back 31

nosocomial/health-acquired pneumonia (HCAP)-Pseudomonas aeruginosa

Front 32

Describe the chest x-ray and gram stain of HCAP caused by P. aeruginosa

Back 32

Chest x-ray: edema over both left and right lower lobes
Sputum gram stain-gram negative rods (not definitive for P. aeruginosa)

Front 33

List the pathogens associated w/ HCAP and risk factors for it's acquisition

Back 33

1. P. aeruginosa (most common)
2. S. aureus (2nd most common)
note-S. pneumonia is low incidence
healthy orthopedic patients-not susceptible to HCAP
unhealthy immunocompromised patients-susceptible to HCAP (flora will change if hospitalized long enough)

Front 34

Describe the pathology of CAP vs HCAP

Back 34

CAP-lobar pneumonia
HCAP-diffuse pneumonia (multiple sites); bonchopneumonia-patchy, very inflammatory process (lots of WBCs and RBCs in alveolar spaces)

Front 35

Describe the empirical regimem for treating HCAP

Back 35

Merapenam (carbapenam) and aminoglycoside (gentamicin) note-start w/ 2 drugs that are active against resistant bacilli; cover broadly at first, then narrow spectrum once you get diagnosis (if wrong, choice increases risk of mortality!)

Front 36

A 40-year-old male presents with 10 days of nonproductive cough, dyspnea on exertion, fever, and night sweats. On exam he is mildly cachectic and in moderate distress. Temperature is 39°C. Oropharynx has exudative thrush. Lungs have coarse rales throughout both hemithoraces. Arterial blood gas analysis obtained while breathing room air at rest is: pH 7.50/pCO2 28/pO2 60. WBC count is 3,000 (absolute lymphocyte count is 100), hemoglobin 10 g/dL, and platelets are 140,000. Serum lactate dehydrogenase level is 400 U/L.

Back 36

Pneumocystis pneumonia (PCP)-Pneumocystis jiroveci

Front 37

Describe what the imaging looks like in PCP

Back 37

1. Chest x-ray: Diffuse reticulonodular infiltrate involving multiple lobes (more prominent in perihilar region)
2. High resolution CT: ground-glass opacification; multiple thin-walled cysts consistent w/ pneumatoceles

Front 38

Differentiate PCP from bacterial pneumonia

Back 38

PCP-oral thrush, exertional dyspnea, interstitial infiltrate
Bacterial pneumonia-fever, toxic appearance, rhonchi, lobar infiltrate

Front 39

Describe the culture and biopsy of PCP

Back 39

biopsy-characteristic foamy honeycomb material seen in alveolar spaces (definitive diagnosis)
sputum culture-Can’t get any in sputum (since infection in alveoli); bronchioalveolar lavage (BAL)-can’t see organism on silver stain

Front 40

What should you be suspicious of in any patient w/ PCP

Back 40

Be suspicious of opportunistic infection; most commonly presents w/ HIV

Front 41

Describe the pathogenesis of PCP

Back 41

infection starts in alveoli and then moves into interstitium

Front 42

A 65-year-old male with diabetes mellitus is admitted to the hospital with severe left lower lobar pneumonia. He is empirically started on moxifloxacin. Sputum and blood cultures are negative. After 5 days, fever persists and the patient reports worsening dyspnea and left sided chest pain which intensifies with inspiration. Lung exam reveals decreased breath sounds, flat percussion at left lower lung fields and hyperresonant at left upper lung fields. Repeat chest radiograph is obtained

Back 42

Empyema-S. pneumonia; Klebsiella pneumonia

Front 43

What are symtoms of a non-responder to pneumonia treatment?

Back 43

Persisting fever, worsening dyspnea-indicates complication (abscesss, empyema/effusion)

Front 44

What is empyema?

Back 44

a complicated effusion-lowered pH; inflammatory and/or infected fluid

Front 45

Describe the imaging seen in an empyema

Back 45

1. Chest x-ray: effusion of the left lung
2. CT: fluid on left; compressed left lung; loculation (empyema)

Front 46

Describe thoracentesis in empyema/abscess

Back 46

thoracentesis performed under ultrasound guidance; pleural fluid reveals pH 7.1 (low), LDH 1,000 U/L (high), and glucose 30 mg/dL (low)
Gram stain of pleural fluid-S. pneumonia or K. pneumonia

Front 47

Describe the treatment of an empyema

Back 47

Can’t get drug to bug (since it’s in pleura); drain pleural fluid w/ catheter

Front 48

A 70-year-old male with known heavy alcohol abuse is brought by EMS to the ED with obtundation and hypothermia. The police said they found him unconscious on the sidewalk. On physical exam, temperature is 34°C; he has severe gingivitis, several loose teeth, extensive dental caries, and foul-smelling breath. The right lower lung field has dullness to percussion, amphoric breath sounds, rales, and whispered pectoriloquy. WBC count is 22, 000/mm3. Chest radiograph is shown (see image). Sputum Gram stain shows many neutrophils and a mixture of Gram-positive cocci, Gram-positive rods, and Gram-negative rods. Sputum culture grows “normal mouth flora.” He has no known drug allergies.

Back 48

Necrotizing pneumonia-TANKS

Front 49

What does the imaging show in necrotizing pneumonia

Back 49

Chest x-ray: Abscess in right lower lobe; not in middle lobe because right heart border is crisp; air-fluid level indicates abscess
CT: anaerobic lung abscess showing 2 contiguous thick-walled cavitary lesions in right lower lobe w/ air-fluid levels

Front 50

Describe what would be seen in a sputum gram stain of necrotizing pneumonia

Back 50

Gram negative bacilli and gram positive cocci (bacteriologic diagnosis can't be made)
presence of mixed flora, w/out significant growth of pathogens on routine culture suggests anaerobic involvement
CAP-anaerobic oral flora (Prevotella, Porphyromonas, Peptostreptococcus, and Fusobacterium)
HCAP-enteric gram negative bacilli, Pseudomonas, and S. aureus are common

Front 51

What are the main bugs that cause necrotizing pneumonia?

Back 51

think TANKS
Tuberculosis
Anaerobes
Nocardia
Klebsiella
S. aureus
note-S. pneumonia is not a common pathogen

Front 52

Describe the treatment of necrotizing pneumonia

Back 52

1. Antibiotics (early)
Antibiotics-Pipericillin/Tazobactam (tazo is B-lactamase inhibitor); ertapenem (carbapenam); clindamycin (macrolide)
*when in doubt, use a PCN*
2. CT scan, bronchoscopy-rule out obstruction (cancer)
3. postural drainage (drain through endobronchial tube, not through needle)

Front 53

Describe the pathology of necrotizing pneumonia

Back 53

cardinal histologic change in abscesses is suppurative destruction of lung parenchyma w/in central area of cavitation
Continued infection leads to large, fetid, green-black, multilocular cavities with poor demarcation of their margins (gangrene of the lung)