pulm infectious disease Flashcards
inflammation that causes a cough
bronchitis
- Cough
- lower respiratory tract infection involving the bronchi without evidence of pneumonia that occurs in the absence of chronic obstructive pulmonary disease
- symptoms result from inflammation of the lower respiratory tract and are
most frequently due to viral infection - lasts for at least five days ***
- typically self-limited, resolving within one to three week
acute bronchitis
The incidence of acute bronchitis is highest in _____ when
transmission of respiratory viruses peaks
* Influenza A and B
* Parainfluenza
* Coronavirus types 1 to 3
* Rhinoviruses
* Respiratory syncytial virus
* Human metapneumovirus
late fall and winter
what bacteria most likely causes prolonged cough (acute bronchitis)
(whooping cough, characteristic postussive vomiting, prolonged cough–up to 12 weeks)
B. pertussis
first choice to treat acute bronchitis caused by pertussis
azithromycin
what usually precedes bronchitis
URI
what is the cardinal symptom of acute bronchitis
cough (lasting at least 5 days)
- Cough
- Wheezing
- Mild dyspnea
- Rhonchi
- With prolonged coughing, chest wall or substernal musculoskeletal pain can occur
signs and symptoms of acute bronchitis
diagnostics for acute bronchitis
clinical
make sure they don’t have any other concerning symptoms –> parenchymal consolidation, high fever, possessive emesis, inspiratory whoop
when do you do testing for acute bronchitis
- Suspected pneumonia
- clinical diagnosis is uncertain-suspect flu, pertussis, Covid-19
- results would change management
- a positive influenza test result in a patient who meets criteria for antiviral therapy
acute bronchitis treatment
- mostly supportive
- throat lozenges
- hot tea, honey
- stop smoking
- OTC cough med
- hydration
- humidity
- expectorants
- dextromethorphan
develops outside of hospital
community acquired pneumonia
- hospital acquired pneumonia
- ventilator acquired pneumonia
nosocomial pneumonia
an infection that inflames the air sacs in one or both lungs.
* The air sacs may fill with fluid or purulent material
* cough with phlegm or pus, fever, chills, and difficulty breathing
* caused by variety of organisms, including bacteria, viruses and fungi
fluid in the alveoli
pneumonia
Pulmonary defense mechanisms normally prevent the development
of lower respiratory tract infections following aspiration of
oropharyngeal secretions containing bacteria or inhalation of infected
aerosols causing pneumonia
- cough reflex
- mucociliary clearance system
- immune responses
when does CAP occur
when there is a defect in one or more of these:
* cough reflex
* mucociliary clearance system
* immune responses
or when a large infectious inoculation or a virulent pathogen overwhelms the immune response
what is the most common pathogen in CAP
strep pneumoniae
pneumonia classifications
- where you got the infection (CAP or HAP)
- types of pathogens (bacterial, viral,fungal)
- clinical presentation (typical/atypical)
- extent of involvement and CXR findings (lobar, interstitial, cavitary)
- Fever or hypothermia
- Cough
- Dyspnea
- Sweats/chills
- Chest discomfort, pleuritic chest pain
- Tachypnea, tachycardia
- Hypoxia
- May appear acutely ill
- Inspiratory crackles, bronchial breath sounds***
- Dullness to percussion if lobar consolidation or pleural
effusion
signs and symptoms of pneumonia
- Diagnosed outside the hospital in ambulatory patients who are not
residents of nursing homes or other long-term care facilities - May also be diagnosed in a previously ambulatory patient within 48 hours after admission to the hospital
- Risk factors include: advanced age, alcoholism, tobacco use, comorbid
medical conditions especially asthma or COPD, and immunosuppression
community acquired pneumonia
immunocompromised patients with pneumonia are at risk for
- gram-negative empiric bacteria
- mycobacterium avium complex
- Fungi: aspergillosis
- Viruses: CMV
- pneumocystis jiroveci carinii
Patients with cystic fibrosis at risk for
- Staph aureus in infancy
- Pseudomonas aeruginosa or Burkholderia cepacia in older children
how to diagnose pneumonia (outpatient)
CXR- preferable to confirm diagnosis
(do not have to have definitive pathogen)
pneumonia diagnostics
what does bacterial, viral, and atypical show?
- Bacterial pneumonia shows lobar infiltrates/consolidation, or a round
pneumonia with pleural effusion - Viral pneumonia shows diffuse, streaky infiltrates in the bronchi and
hyperinflation - Atypical pneumonia shows increased interstitial markings or
bronchopneumonia
pneumonia inpatient testing
- Hospitalized patients should have CBC, CMP
- ABG
- CXR: pulmonary opacity is required for diagnosis
classic sign of typical pneumonia
(one lobe affected)
- lobar infiltrates/consolodation
classic sign of atypical pneumonia
increased interstitial markings
classic sign of viral pneumonia
both sides affected
diffuse, streaky inflitrates
pneumonia inpatient testing to identify the pathogen
sputum culture/ gram stain before starting Abx
pneumonia treatment without complications (CAP outpatient empiric Abx)
make sure they are healthy persons who have not taken antibiotics within the past 3 months and not in an area of high macrolide resistant S. Pneumo
azithromycin (at least 5 days), doxy, or amoxicillin
pneumonia treatment if
* infants under 6 months of age with bacterial pneumonia
* concern for a pathogen with increased virulence (MRSA)
* concerns about the patient’s or caregiver’s ability to follow recommendations and to
assess symptom progression
hospitalization
CAP outpatient treatment if they have high risk for drug resistant like
* Abx therapy in last 90 days
* Age > 65
* Comorbidities
* Immunosuppression
* Exposure to a child in day car
Macrolide plus beta lactam (high dose amoxicillin or amox-clav are
preferred)
* Or Respiratory fluoroquinolone (levo, moxi, gemi
CAP – Inpatient Treatment not ICU
Macrolide + beta-lactam (ceftriaxone, cefotaxime, ceftaroline, ampicillin-
sulbactam)
* Or Respiratory Fluoroquinolone
CAP – Inpatient Treatment in ICU
Anti-pneumococcal beta-lactam (cefoxatime, ceftriaxone, ceftaroline, or
ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone
(moxi, gemi, or levofloxacin)
CAP – Inpatient Treatment in ICU
If PCN allergy:
Fluoroquinolone + aztreonam
complications of pneumonia
empyema
lung abscess
sepsis
how to prevent pneumonia
Pneumococcal vaccine for adults age 65 and older and in those who
are immunocompromised or have chronic illnesses
* Annual influenza vaccine
* SARS-CoV-2 vaccine
when to admit for pneumonia
CRB-65 scale
When to admit to ICU for pneumonia?
Major Criteria:
1 major or 3 or more minor
- Septic shock w/ need for
vasopressor support - Respiratory failure w/
need for mechanical
ventilation
when to admit to ICU for pneumonia
* Minor criteria:
1 major or 3 or more minor
- Respiratory rate 30
- Hypoxemia
- Hypothermia
- Hypotension requiring
aggressive fluid
resuscitation - Confusion/disorientation
- Multilobar pulmonary
opacities - Leukopenia
- Thrombocytopenia
- Uremia
- Metabolic acidosis
- Elevated lactate leve
occurs > 48 hours after admission to
the hospital or other health care facility and excludes any infection
present at the time of admission
HAP (nosocomial pneumonia)
develops > 48 hours following
endotracheal intubation
VAP (nosocomial pneumonia)
nosocomial risk factors
- Antibiotic therapy in the preceding 90 days
- Acute care hospitalization for at least 2 days in the preceding 90 days
- Residence in a nursing home or extended care facility
- Home infusion therapy, including chemotherapy, within the past 30 days
- Long-term dialysis within the past 30 days
- Home wound care
- Family member with an infection involving a multiple drug-resistant
pathogen - Immunosuppressive disease or immunosuppressive therapy
what is the pathogenesis of nosocomial pneumonia
Colonization of the pharynx and possibly the stomach with bacteria
Pharyngeal colonization is promoted by exogenous factors:
* instrumentation used during procedures
* contamination by dirty hands
* Equipment
* contaminated aerosols
* treatment with broad spectrum antibiotics that promote the emergence of drug-resistant organisms
- Patient factors also involved: malnutrition, advanced age, altered
consciousness, swallowing disorders, underlying pulmonary and systemic diseases - Within 48 hours of admission, 75% of seriously ill hospitalized patients
have their upper airway colonized with organisms from the hospital
environment
most common organisms in nosocomial pneumonias
Gram positive cocci
* Staph aureus (MSSA, MRSA), Streptococcus
Gram negative bacilli
* Pseudomonas, Klebsiella, E. coli, Enterobacter
- Anaerobic organisms-often polymicrobial
what may play a protective role against development of pneumonia
Gastric acid
why do patients taking antacids, H2 blockers, PPIs, or enteral feeding have a higher risk due to the alteration of the gastric pH
- Change in pH can lead to gastric microbial overgrowth and tracheobronchial colonization
- This leads to increased risk of esophageal, enteric infections, and lower respiratory tract infections
HAP – signs and symptoms
Can be non-specific
* Fever
* Leukocytosis
* Purulent sputum
* Worsening respiratory status
how to make a diagnosis for HAP
Two of these non specific symptoms + new or progressive opacity on CXR
labs for HAP
- Blood cultures
imaging/ labs for pleural effusion (HAP)
thoracentesis with pleural fluid analysis
nosocomial pneumonia empiric treatment. ??
treatment based on risk factors:
* MRSA
* Multiple drug resistant pathogens
* Local antibiograms
* Mortality risk
* Duration is based on severity, response, comorbid condition
* Usually for 7 days, with some difference base
* HAP at high risk for mortality or VAP:
* Must consider and determine whether to cover:
* risk factors for MRSA
* risk factors for MDR
* Pseudomonas
* other gram-negative bacilli
- Atypical PNA
- One of most common pathogens associated with CAP
- mollicute genus of bacteria
- Free living-can be passed person to person through respiratory
droplets - Can also cause lower respiratory tract infection
- Considered most common cause of “walking pneumonia”, as it usually causes a mild PNA
mycoplasma pneumonia
- Common cause of respiratory infection in children and young adults
- may worsen asthma symptoms in children, adolescents, and adults and can also produce wheezing in children who do not have asthma
- rates tend to rise in summer and peak in late fall
mycoplasma pneumonia
mycoplasma pneumonia symptoms
often asymptomatic
mycoplasma pneumonia treatment
URI and Acute bronchitis from Mycoplasma are usually self-limiting and don’t require treatment
Gradual onset: may be heralded by headache, malaise, low-grade
fever, and sometimes sore throat
* Cough (either productive or nonproductive) typically follows and may be accompanied by pleuritic chest pain or shortness of breath.
* Chest soreness from persistent coughing is a common complaint
mycoplasma pneumonia
what do you see on mycoplasma pneumonia chest x ray (varies a lot)
mild patchy hazy opacities
reticular nodular opacities or patchy consolidations
What is treatment for CAP in a young healthy person (mycoplasma pneumonia)
- M. pneumoniae infections may resolve spontaneously
- Doxycycline, Azythromycin, Levofloxacin
- Atypical PNA
- Outbreaks from contaminated water
- showerheads, faucets, air conditioning
- Most common in people who smoke, who have chronic lung disease or are immunocompromised
- N/V/D are often prominent***
legionella pneumonia
how to test for legionella pneumonia
- Culture is 80-90% sensitive
- Sputum PCR is also sensitive
legionella pneumonia treatment
Azithromycin, Clarithromycin or a Fluoroquinolone (Levo)
- Aspiration of oropharyngeal secretions can lead to pneumonia caused by anaerobic bacteria
- typically happens in people with altered consciousness
- Periodontal disease and poor dental hygiene are risk factors
- Pneumonia usually starts in dependent lung zones
- Onset of symptoms is insidious: often by the time the patient seeks
treatment, necrotizing pneumonia, lung abscess or empyema is present - Multiple species of anaerobic bacteria are common
anaerobic pneumonia and lung abscess
- alcoholic
- aspirates
- poor hygiene
anaerobic pneumonia and lung abscess
- Fever
- Weight loss**
- Malaise
- Cough with expectoration of foul-smelling purulent sputum is common**
- Often have poor dentition
signs and symptoms of anaerobic pneumonia and lung abscess
labs and imaging for anaerobic pneumonia and lung abscess
- Culture can only be done via transthoracic aspiration, thoracentesis, or bronchoscopy-can’t use sputum
- lung abscess CXR – thick-walled solitary cavity surrounded by
consolidation; air fluid level is usually present - necrotizing pneumonia CXR – multiple areas of cavitation within an
area of consolidation - Empyema CXR or US – purulent pleural fluid and may have pleural
loculations
thick- walled cavity (white arrow) with a smooth inner margin (red
arrow), located in the right lung.
An air-fluid level is present
(black arrow)
lung abscess
infected effusion and
pleural adhesions frequently
associated with anaerobic
organisms introduced into lung
by aspiration
empyema
Anaerobic PNA/Lung abscess Treatment
- 1st line: β-lactam-β-lactamase inhibitor (BLBLI) combination antibiotics
- such as piperacillin-tazobactam or amoxicillin- clavulanate
- Or a Carbapenem
empyema treatment
Tube thoracostomy or open pleural drainage
most common cause in infants
RSV
most common in children older than age 5
mycoplasma pneumoniae
risk factors for pneumonia in children
- GERD (can occur in infants and children)
- Neurologic impairment: aspiration
- immunocompromised status
- anatomic abnormalities of the respiratory tract: severe
tracheomalacia - hospitalization especially if in an ICU
- common when objects are inhaled
- Neonates – fever, hypoxia, subtle or absent physical exam findings
- Young infant – apnea may be the only sign; +/- fever
- Older infant and young children – fever, chills, tachypnea, cough,
malaise, pleuritic chest pain, retractions, apprehension, difficulty
breathing, shortness of breath - Older children present similarly to adults – fever, cough with or
without sputum production, dyspnea - May also experience sweats, chills, rigors, chest discomfort, pleurisy,
hemoptysis, fatigue, myalgias, anorexia, headache and abdominal pain
pneumonia in children signs and symptoms
- Causes annual outbreaks during winter –peak in Jan, Feb
- Most significant LRI cause in young children worldwide
- Leading cause of hospitalization in children in the US
RSV
RSV prophylaxis
- RSV antibody immunization is recommended for all infants who are
younger than 8 months, born during or entering their first RSV season - IF birth parent did not receive RSV vaccine
- or IF birth is within 14 days of vaccine administration
- Additionally, a dose of RSV antibody (nirsevimab) is also recommended for children between the ages of 8 – 19 months entering their second RSV
season who are in at least one of these groups: - Children who have chronic lung disease from being born premature and are requiring medical therapy for their lung disease
- Children who are severely immunocompromised
- Children with cystic fibrosis who have severe disease
- American Indian and Alaska Native children
major risk factor for RSV
prematurity
what is RSV associated with later in life
airway reactivity (asthma)
Proliferation and necrosis of
bronchiolar epithelium
produces obstruction and
increased mucus secretion
RSV pathophysiology
- Low grade fever
Bronchiolitis:***
* Wheezing
* Cough
* Tachypnea
* Difficulty feeding
* cyanosis
- Grunting in an infant (characteristic)*****
- Crackles**
- Prolonged expiration
- Retractions
- Liver and spleen may be palpable because they are pushed down, but not actually enlarged
- Apnea
- Lethargy
RSV signs and symptoms
how to diagnose RSV
- Clinical diagnosis of bronchiolitis is made in infant or child with
prodrome of upper respiratory infection lasting 1-3 days followed by
persistent cough - plus tachypnea and/or chest retractions
- plus wheeze and/or crackles on auscultation
do you do RSV testing for a healthy kid
no (not routine)
if you have RSV in a patient needing to be hospitalized what testing do you do to identify the pathogen
RT-PCR: reverse transcriptase-polymerase chain reaction with
nasopharyngeal swab
chest xray: hyperinflation and slightly flattened diaphragms**
bronchiolitis (RSV)
RSV treatment
- Time
- Hospitalize if hypoxic or unable to feed
- Respiratory isolation
- Supportive care
- Hydration**
- Humidifier or humidified oxygen
- Nasal suction
- Respiratory support as needed, rarely ventilation
- caused by Mycobacterium tuberculosis.
- Slow growing bacteria
- It can present as a pulmonary illness or have extrapulmonary
involvement. - It is treatable
- Higher rates among
- Malnourished
*Houseless/overcrowding/substandard housing - HIV-positive pts
- IVDU
tuberculosis
how is TB spread
aerosolized droplets
– then alveolar macrophages ingest TB
- TB spread by aerosolized droplets
- Alveolar macrophages ingest TB
- If macrophage microbicidal activity fails, infection follows
- Lymph and hematogenous spread occurs, causing:
primary TB
T cells and macrophages in health people surround the organisms and
contain them in granulomas, which prevents spread, and the disease
can remain dormant which is not infectious and not active
latent TB
reactivation of TB
active TB
TB screening for health care workers
tuberculin skin test (TST) and interferon-gamma release assays (IGRAs)
- Slowly progressive constitutional Sx
- Malaise, anorexia, weight loss, fever, night sweats
- Chronic cough-starts dry them changes to productive
- most common symptom is productive cough for > 2 weeks
- Blood-streaked sputum
PE:
* Chronically ill
* Malnourished
* No specific pulm findings
signs and symptoms of TB
standard testing screening test for TB
Mantoux PPD test
- 0.1 mL of purified protein derivative (PPD) containing 5 tuberculin
units is injected intradermally on the volar surface of the forearm
using a 27-gauge needle on a tuberculin syringe. - The transverse width in millimeters of induration at the skin test site
is measured after 48–72 hours** - To optimize test performance, criteria for determining a positive
reaction vary depending on the likelihood of infection
size on induration of PPD
less than 5mm results
negative for TB
size on induration of PPD
at least 5mm results positive if:
- you’ve had recent contact with someone with TB
- you are HIV positive
- had an organ transplant
- taking immunosuppressants
- previously had TB
size on induration of PPD
at least 10mm results positive if:
- recently immigrated from a country with high incidence of TB
- live in high risk environment
- work in hospital, medical lab, or other high risk setting
- child under age of 4
- used injected drugs
size on induration of PPD
at least 15mm results:
positive
- Previous TB vaccination with the bacille Calmette-Guérin (BCG)
vaccine - Infection with nontuberculosis mycobacteria (mycobacteria other
than M. tuberculosis) - Incorrect measurement or interpretation of reaction
- Incorrect antigen used
- TB blood tests–interferon-gamma release assays or IGRAs are
preferred method for people who have received the vaccin
TB false positives for TST
who should be tested for TB
- People who have spent time with someone who has TB disease
- People from a country where TB disease is common
- People who live or work in high-risk settings (for example:
correctional facilities, long-term care facilities or nursing homes, and
homeless shelters) - Health-care workers who care for patients at increased risk for TB
disease - Infants, children and adolescents exposed to adults who are at
increased risk for latent tuberculosis infection or TB disease
what do you do after positive screening TB test
- Chest XR and Physical exam
- May do other testing depending on suspicion
latent TB treatment
Isoniazid plus rifapentine once weekly for 3 months recommended for adults and children aged ≥ 2 years, including persons with HIV if drug interactions allow.
* Rifampicin monotherapy daily for 4 months recommended for adults and
children without HIV.
* Isoniazid plus rifampicin daily for 3 months in adults and children without HIV and persons with HIV if drug interactions allow
gold standard for suspected TB infection to identify pathogen
sputum culture-6-8 week return
active TB treatment 6 month regimen
- Directly observed therapy (DOT): requires that a health care worker
physically observe the patient ingest antituberculous medications in
the home, clinic, hospital, or elsewhere, also improves adherence to treatment.
6 month regimen:
* The initial phase of a 6-month regimen consists of 2 months of daily isoniazid, rifampin, pyrazinamide, and ethambutol
* Once the isolate is determined to be isoniazid-sensitive, ethambutol may be discontinued.
- If the M tuberculosis isolate is susceptible to isoniazid and rifampin, the second phase of therapy consists of isoniazid and rifampin for a minimum of 4 additional
months - treatment extends at least 3 months beyond documentation of conversion of sputum cultures to negative for M tuberculosis
active TB treatment 9 month regimen
9 month regimen for those who cannot take pyrazinamide:
* daily isoniazid and rifampin along with ethambutol for 4–8 weeks
* If susceptibility to isoniazid and rifampin is demonstrated or drug
resistance is unlikely, ethambutol can be discontinued, and isoniazid
and rifampin may be given for a total of 9 months of therapy
drug resistant TB is resistant to either
isoniazid or rifampin
multidrug resistant TB is resistant to
both isoniazid or rifampin and possible others
active TB precautions
Hospitalized patients with active disease require a private room with appropriate
environmental controls, including negative-pressure ventilation where available, until tubercle bacilli are no longer found in their sputum (“smear-negative”) on three
consecutive smears taken on separate days
- occurs due to lymphohematogenous spread and commonly involves
multiple organs - millet seed-sized (1 to 2 mm) tuberculous foci—disseminated disease
- accounts for 1%-2% of TB cases
- typically presents 2-6 months after initial infection
miliary TB
miliary TB treatment
same as pulmonary TB
rifampin side effects
red-orange secretions and urine
- Disseminated:
- at least two non-contiguous organ sites of the body
- or infection of the blood, bone marrow or liver.
- Miliary mottling on a chest radiograph is the classical hallmark
- classified as both pulmonary and extrapulmonary tuberculosis
miliary TB
ethambutol side effects
visual problems
isoniazid side effects
peripheral neuritis
pyrazinamide side effects
increased uric acid
streptomycin side effects
ototoxic
causes acute respiratory disease
* Transmitted primarily through respiratory droplets within close
contact
* Aerosol, fomites
* Dysregulated inflammatory response and a hypercoagulable state
* Viral protein binds the ACE2 receptors
* Causes dysregulation of renin-angiotensin-aldosterone system
covid 19
- Symptoms arise 2-14 days after exposure, mean incubation of 5 days
- Fever or chills
- Cough, SHOB
- HA, muscle aches, dizziness, fatigue
- Sore throat, congestion, runny nose
- Loss of smell or taste***
- N/V/D, abdominal pain, anorexia
- Confusion, impaired consciousness
- Rash
- Asymptomatic in up to 30% of patients
covid 19
current preferred
method of confirmation for covid 19
SARS-CoV-2 nucleic acid amplification test is current preferred
method of confirmation-usually done by nasal swab
- Infection from Aspergillus fumigatus
- Lungs, sinuses and brain are most frequently involved organs
- 3 clinical syndromes: Allergic, chronic, invasive
- Invasive: disease of the immunocompromised or critically ill
- At risk with COVID-19
- Severe necrotizing PNA
- Invasive sinus disease
- Possible CNS or other organ involvement
aspergillosis
covid 19 treatment
- Hospitalization on a case-by-base basis
For non-hospitalized patients:
* Supportive care and try to reduce transmission
Consider for pts at high-risk for disease progression:
* Nirmatrelvir/ritonavir (Paxlovid)
how to get a definitive diagnosis for invasive aspergillosis
tissue or culture
what should you do if you have a clinical suspicion of invasive aspergillosis
chest CT: nodules, wedge shaped infarcts, halo sign
Invasive Aspergillosis
* Prophylaxis for high risk Pts:
- Posaconazole or voriconazole
invasive aspergillosis treatment
- 1st choice: IV voriconazole
