Pulmonology Infections: Pt 1 & 2 Flashcards
(136 cards)
1
Q
Community-Acquired Pneumonia (CAP)
A
● Pneumonia is an acute inflammation of the lungs caused by infection
● CAP develops in people with no or limited contact with healthcare facilities or settings
● Leading cause of death in the US
and world
2
Q
Most common pathogens of Community-Acquired Pneumonia (CAP)
A
● Streptococcus pneumoniae
● Haemophilus influenzae
● Atypical bacteria
○ Chlamydia pneumoniae
○ Mycoplasma pneumoniae
○ Legionella pneumophila
● Viruses
3
Q
Common viral agents include of CAP:
A
● RSV
● Adenovirus
● Influenza virus
● Metapneumovirus
● Parainfluenza virus
4
Q
Common fungal agents of CAP:
A
● Histoplasmosis
● Coccidioidomycosis
5
Q
Community-Acquired Pneumonia (CAP) S/S:
A
● Fever, chills
● Cough
● Sputum production
● Pleuritic chest pain
● Dyspnea- generally mild and exertional
● Crackles, rales, bronchial breath sounds, egophony
● Tachypnea
● Tachycardia
● GI symptoms are common- nausea, vomiting, diarrhea
6
Q
Diagnosis of CAP:
A
● Clinical presentation
● Chest x-ray
○ Opacities - difficult to distinguish one type from another
● Sputum testing- may include Gram stain and culture
7
Q
Chest x-ray suggestive finding for CAP:
A
● Multilobar infiltrates suggest S. pneumoniae or Legionella pneumophila
infection
● Interstitial pneumonia (on chest x-ray- increased interstitial markings) suggests viral or mycoplasmal etiology
● Cavitating pneumonia suggests S. aureus or a fungal or mycobacterial etiology
8
Q
Treatment of CAP:
A
● Risk stratification
○ To determine if patient should be treated as outpatient or inpatient
● Antibiotics (often empirically chosen for pts with mild to moderate risk without testing for pathogen)
● Antivirals, if needed
● Supportive measures
○ Fluids, antipyretics, analgesics, oxygen (if needed)
○ Smoking cessation counseling
9
Q
Antibiotic Treatment for CAP For healthy patients, <65 years, and no recent abx use:
A
● Amoxicillin 1g PO three times daily x 5-7 days
Or
● Doxycycline 100 mg twice daily x 5-7 days
Alternative: Macrolides
10
Q
Antibiotic Treatment for CAP
For patients with comorbidities:
A
● Amoxicillin-clavulanate 875/125 mg twice daily
Plus
● Macrolide (i.e., azithromycin, clarithromycin)
Or
● Doxycycline 100 mg twice daily
11
Q
Failure for CAP to improve with Abx should trigger concern for:
A
● Nonadherence (outpatient)
● An unusual organism
● Coinfection or superinfection with a secondary organism
● Empyema
● Resistance to antimicrobial therapy
● Immunosuppression
12
Q
Community-Acquired Pneumonia (CAP) Prognosis:
A
● Excellent for young or healthy
individuals
● Less optimistic for older, sicker people especially when caused by S. pneumoniae, Legionella, Staphylococcus aureus, or
influenza virus
13
Q
Community-Acquired Pneumonia (CAP) prevention:
A
● Smoking cessation
● Vaccines
14
Q
Healthcare-Associated Pneumonia (HCAP) has two types:
A
Nosocomial pneumonia:
● Hospital-associated pneumonia (HAP)
○ Occurs more than 48 hours after patients have been admitted to the hospital; excludes
infection present at the time of admission
● Ventilator-associated pneumonia (VAP)
○ Develops more than 48 hours after endotracheal intubation and mechanical ventilation
15
Q
Nosocomial infections differ from
CAP in 3 ways
A
● Different, less common infectious causes
● Higher incidence of drug resistance
● Poor underlying health of patients
16
Q
Common organisms in nosocomial pneumonias:
A
● Streptococcus pneumonia (often drug-resistant)
● Staphylococcus aureus (MSS and MRSA)
● Klebsiella pneumonia
● Haemophilus influenzae
● Escherichia coli
● Enterobacter species
● Pseudomonas aeruginosa
● Acinetobacter species
17
Q
S/S HAP:
A
● Nonspecific; similar to CAP
18
Q
S/S VAP:
A
Generally nonspecific but may
have two of the following:
● Fever
● High WBC count
● Purulent sputum
Plus chest x-ray with new or progressive opacity
19
Q
Diagnosis of HAP:
A
● A new lung infiltrate plus clinical evidence of infection
● Arterial blood gas or pulse oximetry may help
determine severity of illness and need for
ventilation
● Sputum stain and culture - similar to CAP - not always helpful
● Bronchoscopic specimen
20
Q
Hospital-Acquired Pneumonia (HAP) Treatment
A
Should begin antibiotic regimen quickly due to high mortality rates
Use one:
● Piperacillin-tazobactam
● Cefepime
● Levofloxacin
21
Q
Treating High risk HAP:
A
Use one from each category:
● Cefepime
● Imipenem
● Piperacillin-tazobactam
● Aztreonam
● Ceftazidime
● Meropenem
● PLUS
○ Linezolid
○ Vancomycin
○ Telavancin
● PLUS
○ An aminoglycoside (gentamicin or tobramycin)
○ An antipseudomonal fluoroquinolone (cipro or levofloxacin)
○ A polymixin (polymixin B)
22
Q
Streptococcal Pneumonia
A
● Caused by the Streptococcus pneumoniae bacteria
○ Gram-positive encapsulated diplococci
● Spread via airborne droplets
● Pleural effusions occur in approx 40% of patients
● Pneumococcal diseases also include otitis media, sinusitis, bacteremia, endocarditis, meningitis
○ Pneumonia being the most frequent serious infection
● Lobar pneumonia
23
Q
Streptococcal Pneumonia epidemiology
A
● Traditionally, it has been the most common cause of CAP
○ Incidence has decreased to 5-15% probably due to the
pneumococcal vaccine and a reduction in cigarette smoking
24
Q
RFs for streptococcal pneumonia
A
● Influenza infection
● Alcohol abuse
● Smoking
● Splenectomy
● Immunocompromised
● COPD and asthma
25
Streptococcal Pneumonia S/S
● Fever, chills
● Cough
○ Sputum can be “rust” colored
● Tachypnea
● Rales and bronchial breath sounds
localized at the involved lobe or site
26
Streptococcal Pneumonia Diagnosis
● Gram stain and culture
○ Easy to identify as lancet-shaped diplococci
○ Best seen using the Quellung test- India ink stains the capsule. May also use methylene blue stain
27
Streptococcal Pneumonia Treatment
● Antibiotic
○ Beta-lactam (Amoxicillin, PCN G)
○ Macrolide
○ Respiratory fluoroquinolone
Resistant strains have emerged which have made treatment difficult. May
consider later-generations of cephalosporins or combination therapy
27
Klebsiella Pneumonia
Caused by the Klebsiella pneumoniae bacteria, a
type of Enterobacteriaceae
● Has been associated with UTIs, pulmonary infections, bacteremia
● A rare and severe disease
● Part of the normal flora of the mouth and intestine
● Infections are usually hospital acquired
● Common among diabetics and alcoholics
27
Klebsiella Pneumonia
● Infections are common among those with decreased immune systems, including alcoholics, diabetics, cancer patients, patients with COPD or renal failure etc.
● Often acquired in hospitals or long-term care facilities, including
patients on ventilators
28
Major risk factors for klebsiella pneumonia
● Prior antibiotic use
● Use of invasive plastic devices (i.e., bladder catheters, endotracheal tubes)
29
Klebsiella Pneumonia S/S
● Fever, cough, increased sputum production,
increased WBC count, lung crackles,
pleuritic chest pain, dyspnea, tachypnea
○ Nonspecific bacterial pneumonia
symptoms
● Red, “currant jelly” sputum
○ Thick, mucoid and blood-tinged
sputum
30
Klebsiella Pneumonia diagnosis
● Confirmed by culture of
sputum or aspirated body fluid
including pleural effusion
○ Gram stain
● CXR for suspected pneumonia
● Imaging for suspected abscess
formation in the liver, spleen,
kidneys, etc
31
Klebsiella Pneumonia Tx
● Antibiotic choice depends on susceptibility
○ Resistance is increasing
● May drain abscesses
32
Staphylococcal Pneumonia
● Caused by the Staphylococcus
aureus bacteria
○ Gram-positive cocci
● A rapidly progressive disease
33
Staphylococcal Pneumonia epidemiology:
● In community-acquired pneumonia, it commonly affects:
○ Older adults, infants
○ Younger patients, previously healthy, recovering from influenza (post-influenza pneumonia)
■ High mortality rate
● Community-associated methicillin-resistant S. aureus (CA-MRSA) is often associated with severe necrotizing pneumonia
34
Staphylococcal Pneumonia S/S
● Short prodrome of fever
● Followed by respiratory symptoms, then respiratory distress
● May have GI symptoms
35
Diagnosis of Staphylococcal Pneumonia
● Sputum specimens are inadequate because upper respiratory tract
colonization is common
● No radiologic features are highly specific
36
Staphylococcal Pneumonia Treatment
● Antibiotics
○ Empiric therapy with penicillins or cephalosporins may be
inadequate because of community-associated
methicillin-resistant Staphylococcus aureus (CA-MRSA)
○ Clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), rifampin, doxycycline, or a quinolone
37
Legionnaires Pneumonia
● Legionnaires disease is caused by the Legionella pneumophila bacteria
○ Often present in soil and freshwater and can be transmitted through plumbing systems via freshwater sources. Outbreaks are often spread through a building’s water supply
○ The infection is usually caused by inhaling
droplets of contaminated water
38
Legionnaires Pneumonia S/S
● Flu-like symptoms: acute fever, chills, malaise, body aches,
headache
● May also have nausea, vomiting,
diarrhea, abdominal pain
● Pulmonary symptoms may include
dyspnea, pleuritic pain, and cough
39
Legionnaires Pneumonia diagnosis
● PCR testing
● Sputum culture
● Urinary antigen
● CXR may show patchy, asymmetric, progressive infiltrates, +/- pleural effusions
40
Legionnaires Pneumonia treatment
● Macrolides- preferably azithromycin
● Fluoroquinolones - levofloxacin
41
Mycoplasma Pneumonia
● Mycoplasma pneumoniae is one of the most common causes
of pneumonia, URIs, and acute bronchitis.
○ An atypical pathogen- a short rod without a cell wall, so it does not show up on Gram stains and is resistant to beta-lactams
● Typically community acquired and mild
42
Mycoplasma Pneumonia epidemiology
● More frequent in summer and fall
● Young adults, children
● Transmitted person to person, via
respiratory droplets
○ Epidemics are more common
among people in close quartersmilitary, university dorms etc
43
Mycoplasma Pneumonia S/S
● Onset is gradual
● Begins with headache, sore throat, low-grade fever, malaise (URI sxs)
● Cough (+/- sputum) follows, then chest soreness, shortness of breath (acute bronchitis)
● May also have extrapulmonary symptoms such as hemolytic
anemia, skin rashes, hepatitis
44
Mycoplasma Pneumonia Diagnosis
● Clinical
● CXR- patchy opacities, reticulonodular
● NAATs- Nucleic acid amplification testsdiagnostic method of choice
45
Treatment of Mycoplasma Pneumonia
● Empiric
○ Should target atypical and typical bacteria
● Outpatient tx- macrolide, doxycycline, or
respiratory fluoroquinolone
46
Mycoplasma Pneumonia Prevention
● Hand and respiratory hygiene
● Inpatient patients should be placed on droplet precautions
● No vaccination is currently available
47
Three most common: Fungal Pneumonia
● Pneumocystis jirovecii
● Aspergillus species (especially A. fumigatus)
● Cryptococcus neoformans
48
Pneumocystis pneumonia
● Pneumocystis jirovecci pneumonia (PJP)
○ Common in immunocompromised patients, especially HIV-infected
patients and those receiving systemic corticosteroids
● Transmitted by aerosol route
● Used to be called: Pneumocystis carinii pneumonia (PCP)
49
Pneumocystis pneumonia S/S
● Fever
● Dyspnea
● Dry, nonproductive cough
50
Risk Factors for Pneumocystis pneumonia
● Patients with HIV infection and CD4+ T lymphocyte counts < 200/μL
● Organ transplant recipients
● Patients with hematologic cancers
● Patients taking corticosteroids
● Advanced immunosuppression in pts not taking antiretroviral therapy
51
Pneumocystis pneumonia Diagnosis
● Chest x-ray
○ Often shows bilateral, diffuse perihilar infiltrates
● Pulse oximetry
○ Hypoxemia- common, even with normal CXR
○ If abnormal, consider obtaining ABGs to assess severity of hypoxemia
● Histopathologic confirmation
○ Testing done on induced sputum or bronchoscopically obtained sputum
52
Pneumocystis pneumonia prognosis
● Mortality for hospitalized patients is 15-20%
53
Risk Factors for death with Pneumocystis pneumonia
● Previous infection of P. jirovecci pneumonia
● Old age
● HIV patients with CD4+ T lymphocyte count <50/μl
54
Pneumocystis pneumonia Treatment:
● Trimethoprim/sulfamethoxazole (TMP-SMX)
○ Give for 14-21 days
● Corticosteroids
55
Prevention of Pneumocystis pneumonia
● HIV infected patients who have previously had P. jirovecci pneumonia or those with CD4+ T lymphocyte count <200/μl may
be treated prophylactically with daily
trimethoprim/sulfamethoxazole (TMP-SMX), or dapsone
56
Haemophilus Pneumonia
● Caused by Haemophilus influenzae bacteria
○ Causes a variety of illnesses- sinusitis, cellulitis, epiglottitis, meningitis
○ Colonizes the human respiratory tract
● Is spread via airborne droplets and direct contact with respiratory secretions
● There are various strains of H. influenzae
○ Hib vaccine covers the H. influenzae serotype B which reduces bacterial
meningitis in children
○ Nontypeable H. influenzae causes community-acquired pneumonia
57
Haemophilus Pneumonia treatment:
● Empiric antibiotic treatment
● If susceptible, beta-lactam agents are preferred:
○ Amoxicillin
○ Second- or third-generation cephalosporins
58
Chlamydia Pneumonia
● Chlamydiae are nonmotile, obligate intracellular bacteria
○ 3 species cause human disease: Chlamydia trachomatis, C. pneumoniae, and C. psittaci
● C. pneumoniae causes pneumonia and other respiratory tract infections
○ Primarily in children and young adults
○ Is often clinically indistinguishable from pneumonia caused by
Mycoplasma pneumoniae
○ Often called “walking pneumonia” or “atypical pneumonia”
○ Typically community acquired and mild
59
Often called “walking pneumonia” or “atypical pneumonia”
Chlamydia Pneumonia
60
Chlamydia Pneumonia epidemiology
● Outbreaks are more common for people in closed populations (ie,
nursing homes, prisons, military groups, families, university dorms)
● No seasonal variations have been noted
61
Diagnosis of Chlamydia Pneumonia
● Sputum culture
● NAAT testing
62
Chlamydia Pneumonia S/S
● Sinusitis, laryngitis, and pharyngitis are more likely to precede coughing, which may be frequent and worsened by bronchospasms
● Fever and shortness of breath
63
Chlamydia Pneumonia treatment
● Azithromycin or doxycycline are first line for outpatients
● For inpatients, a respiratory fluoroquinolone OR beta-lactam PLUS
a macrolide
64
Pseudomonas Pneumonia
● Pseudomonas aeruginosa causes severe cases of pneumonia
○ Gram-negative bacilli
● Hospital-acquired, especially in ventilator and burn patients
○ It favors moist environments
● Community-acquired infections are less common
○ HIV-infected pts and pts with cystic fibrosis
● Pseudomonas infections can occurs in several anatomic regionsskin, urinary tract, bone, ears, etc
65
Pseudomonas Pneumonia epidemiology:
● Commonly found in hospitalized, ICU, and/or ventilator patients
○ Can occur via aspiration of endogenous oral flora or contaminated ventilator tubing or other devices
66
Pseudomonas Pneumonia S/S
● Fever, chills
● Productive cough
● Confusion
● Dyspnea
● Severe system toxicity
67
Pseudomonas Pneumonia diagnosis
● Sputum culture
68
Pseudomonas Pneumonia treatment
● IV antibiotics
● Until antibiotic susceptibility reports are back, begin treatment with one
antibiotic (unless pt has sepsis or indication of drug resistance, then use
two)
○ Single agent- an active antipseudomonal beta-lactam (eg,
ceftazidime) or a fluoroquinolone
○ P. aeruginosa is often resistant to commonly used antibiotics
69
Antibiotic combinations for Pseudomonas Pneumonia
● An antipseudomonal beta-lactam PLUS an antipseudomonal quinolone
● An antipseudomonal beta-lactam PLUS an aminoglycoside
● An antipseudomonal quinolone PLUS an aminoglycoside
70
Pseudomonas Pneumonia prognosis
● High in-hospital mortality rates
● Prolonged lengths of stay
71
Pneumonia Severity Index (PSI): Stage I factors:
●Age >50 years
●The presence of coexisting conditions:
*Neoplastic disease
*Heart failure
*Cerebrovascular disease
*Renal disease
*Liver disease
●The presence of physical examination
abnormalities:
*Altered mental status
*Pulse ≥125/minute
*Respiratory rate ≥30/minute
*Systolic blood pressure <90 mmHg
*Temperature <35°C or ≥40°C
72
CURB-65 acronym
Confusion (new onset)
Urea (BUN) >7 mmol/L (20 mg/dL)
Respiratory rate > 30 breaths/minute
Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
Age > 65 years
73
CURB-65 scoring:
● Patients with a CURB-65 score of 0 can be managed as outpatients
● Patients with a CURB-65 score of 1 or 2 should generally be
admitted to a general medical ward, although patients who receive a
score of 1 because they are ≥65 years of age who do not have major
comorbidities do not necessarily require hospital admission
● Patients with a CURB-65 score of 3 to 5 should be admitted to
the hospital and ICU admission should be considered
74
Tuberculosis
● Tuberculosis (TB) is a chronic, progressive mycobacterial infection
○ Caused by Mycobacterium tuberculosis
○ Most commonly affects the lungs
○ After initial infection there is often a period of latency
● Mycobacteria are slow growing, small bacilli.
○ The cell envelope is lipid rich, comprised of mycolic acid
■ Does not hold gram stain
■ Does hold other stains after an acid rinses: acid-fast
● Transmitted via droplets
75
Tuberculosis epidemiology:
● About 25% of the world’s population is infected (per ppd results)
○ Of those, about 15 million have the active disease
● TB is a leading infectious cause of mortality and morbidity across the world
○ Mortality is high with HIV/AIDS coinfection
● High risk populations include: people who are homeless and people who live in group facilities (prisons, shelters, long-term care
facilities)
76
Tuberculosis pathophysiology
● Primary infection
○ About 95% are asymptomatic
○ Infection is not usually transmittable
● Latent infection
○ NOT contagious
○ May reactivate and progress to symptomatic disease
● Active infection
77
Primary infection with TB:
● Early in the infection, infected macrophages access the lymph system and
then the bloodstream
○ May then spread to any part of the body, often the apical-posterior
portion of the lungs, long bones, meninges, kidneys
● Symptoms, if present, vary.
○ Fever- 70% of symptomatic pts
● Chest x-ray may be normal
○ If not, hilar adenopathy (65%) was often present, pleural effusions (33%)
78
Tuberculosis Latent infection:
● The bacteria becomes
encased into granulomas
○ May be caseating
(necrotizing)
● May remain for years
● May become active at any
time
79
Tuberculosis active infection:
Healthy people who are infected with TB have about a 5 - 10% lifetime risk of
developing active disease
In 50 - 80% of those who develop active disease, TB reactivates within the first 2
years, but it can also occur decades later
● Reactivation occurs, most often in the lung apices
● Conditions that lower immune system, such as HIV, significantly increase
likelihood of disease reactivation
80
Signs and symptoms in active pulmonary TB
● May have vague symptoms- decreased appetite, fatigue, weight loss
○ Which develop over several weeks
● Cough is common
○ Becomes more productive as the disease progresses
○ Hemoptysis only occurs with cavitary TB
● Low-grade fever and night sweats; dyspnea
● Extrapulmonary TB manifestations depend on what organ system is
affected
81
Complications of pulmonary TB:
● Hemoptysis
● Pneumothorax
● Bronchiectasis
● Extensive pulmonary destruction (including pulmonary gangrene)
● Malignancy
● Venous thromboembolism
● Pleural effusion
82
Tuberculosis Diagnosis:
● Chest x-ray
● Acid-fast stain and culture
● Tuberculin skin test
● Nucleic-acid based testing, if available
83
Treatment for tuberculosis:
● Often respiratory isolation
● Refer to a TB specialist
● Antibiotics
84
Antibiotics for Tuberculosis:
● Isoniazid (INH)
● Rifampin (RIF)
● Pyrazinamide (PZA)
● Ethambutol (EMB)
85
Tuberculosis Prevention:
BCG vaccine is given to > 80% of the world’s children, mostly in high-burden countries. Average
efficacy is probably only 50%. Rarely given in the United States.
86
Acute Bronchitis
Acute bronchitis is inflammation of the tracheobronchial tree, commonly
following a URI, that occurs in patients without chronic lung disorders.
● Typically self-limiting between 1-3 weeks
● Symptoms results from inflammation in the lower respiratory tract
● Most frequently caused by viral infection (90%)
● Antibiotics are commonly overused for this condition
87
Most common viral pathogens in Acute Bronchitis
● Influenza A and B
● Parainfluenza
● Coronavirus
● Rhinoviruses
● Respiratory syncytial virus
● Human metapneumovirus
88
Bacterial pathogens are uncommon
but the most frequently seen with Acute Bronchitis
● Bordetella pertussis
● Mycoplasma pneumoniae
● Chlamydia pneumoniae
● Streptococcus pneumoniae
89
Acute Bronchitis S/S
● Cough (with or without sputum production)
● May also have URI symptoms, either before or during
● Fever is rare
90
Acute Bronchitis diagnosis
● Clinical diagnosis
● May obtain CXR- often normal/nonspecific
○ Rule out pneumonia
91
Acute Bronchitis treatment
● Supportive treatment/symptom relief:
○ Acetaminophen/NSAIDs
○ Hydration
○ Possibly antitussives
○ Albuterol inhaler for wheezing
Self-limiting, resolving in 1-3 weeks
92
Acute Bronchiolitis
Bronchiolitis is an acute viral infection of the lower respiratory tract
affecting infants < 24 mo and is characterized by respiratory distress,
wheezing, and crackles
93
Acute Bronchiolitis Epidemiology
● Affects infants and children < 24 months
● Most common during late fall and winter
● A leading cause of hospitalization in infants and young children
94
Most cases of bronchiolitis are caused by _____
RSV. Also, rhinovirus and
parainfluenza, type 3
95
Acute Bronchiolitis pathophysiology
● Viruses infect the bronchi and
bronchioles causing damage and inflammation in the epithelial
cells.
● Edema, excessive mucus, and
sloughed epithelial cells lead to
airway obstruction and atelectasis, also alveolar air trapping.
96
Acute Bronchiolitis S/S
● URI symptoms
● Progressively increasing respiratory distress
○ Tachypnea, retractions, wheezing, hacking cough, nasal flaring
● Severe? Hypoxia, persistently
increased respiratory effort
● Dehydration may develop
97
Diagnosis of Acute Bronchiolitis
● Clinical diagnosis
● Pulse oximetry
● CXR for severe cases
● RSV antigen test
98
Acute Bronchiolitis treatment
● Supportive treatment
● O2, if needed
● IV hydration, if needed
99
Acute Bronchiolitis indications for hospitalization:
● Accelerating respiratory distress
● Ill appearance (eg, cyanosis, lethargy, fatigue)
● Apnea by history
● Hypoxemia
● Inadequate oral intake
100
Respiratory Syncytial Virus (RSV)
● Classified as a pneumovirus
● Common- almost all children will
be infected by age 4
● Two major subtypes: A and B
● Suspected in infants and young
children with bronchiolitis and
pneumonia
101
Respiratory Syncytial Virus (RSV) epidemiology
● Causes seasonal outbreaks (Oct/Nov to April/May in northern hemisphere)
● The most common cause of lower respiratory tract infection
(LRTI) in children younger than one year
● In the US, most pediatric RSV deaths occur in children born prematurely and those with underlying cardiopulmonary disease
or other chronic conditions
102
Risk Factors for RSV:
● Infants younger than <6 months
● Infants born before 35 weeks gestation
● Pts with underlying cardiopulmonary issues or immunocompromised pts
● Infants exposed to secondhand smoke
● Pts with Down Syndrome
● Pts of any age group with significant asthma
103
RSV pathophysiology
● A proliferation and necrosis of bronchiolar epithelium develop, producing obstruction from sloughed epithelium and increased
mucus secretion
104
S/S of RSV:
● URI sxs and low-grade fever, then
tachypnea, cough, crackles and wheezes
● Apnea- may be the initial presenting sxs in
infants < 6 months
105
RSV diagnosis:
● Clinical evaluation
● Nasal swab- PCR or ELISA
106
RSV treatment:
● Supportive care
● Aerosolized Ribavirin previously used. Oral is cheaper and just as effective
● Palivizumab (Synagis) and Nirsevimab (Beyfortus) are anti-RSV monoclonal
antibodies used for prevention in high risk infants.
● Corticosteroids and bronchodilators- not recommended
● Antibiotics would be used only if concern for bacterial coinfection
● 2 Vaccines (Abrysvo and Arexvy) available for those over 60 yo approved in 2023
107
Croup (Laryngotracheobronchitis)
● Croup is an acute inflammation of upper and lower respiratory tracts
● Most common pathogens: Parainfluenza Viruses esp Type 1
108
Croup (Laryngotracheobronchitis) epidemiology
● Mostly affects children aged 6 months to 3 years
● More common in boys than girls
● Family history of croup is a risk factor for croup
● Common in fall or early winter
● ED visits for croup occur most often from 10pm to 4am
109
Croup pathophysiology
● Causes inflammation of the larynx,
trachea, bronchi, bronchioles, and
lung parenchyma
● Obstruction caused by swelling and
inflammatory exudates develops
and becomes pronounced in the
subglottic region
● Work of breathing increases
110
S/S of croup:
● Often preceded by URI sxs for 1-3 days
● Barking cough, inspiratory stridor;
hoarseness- worse at night and with
patient agitation
● “Seal -like”
111
Diagnosis of Croup:
● Clinical presentation (i.e. barking
cough, inspiratory stridor)
● X-rays
112
Croup treatment:
● Humidified air
● Fever reduction
● Encourage fluid intake
● Single dose of long acting steroid (Dexamethasone)
Moderate to Severe
● Dexamethasone and nebulized epinephrine
Westley croup severity score (mostly used for research)
113
Pertussis (Whooping cough)
● Highly contagious respiratory disease caused by Bordetella pertussis
● Incubation period is normally 1 week but can be up to 3 weeks
● Spread via respiratory droplets
● Rising incidence of pertussis due to: adults with waning immunity,
decreased vaccinations, increased clinician awareness etc.
● Infants (esp <6 months) are at greatest risk
114
Pertussis (Whooping cough) pathophysiology
● Bacteria adheres to the cilia of the respiratory epithelial cells,
produces toxins that damages the cilia cells, and causes
inflammation of the respiratory tract, which interferes with the
clearing of pulmonary secretions
● Cells must regrow for recovery
115
Pertussis (Whooping cough) diagnosis
● Nasopharyngeal cultures to isolate bacteria, direct fluorescent antibody testing, PCR
116
3 stages of pertussis
1. Catarrhal- Begins gradually with sneezing, coryza, lacrimation, anorexia, malaise, a nocturnal cough that gradually occurs during the day; similar to URI sxs. Most contagious stage
2. Paroxysmal- After 10-14 days the cough worsens- paroxysms of cough, an inspiratory whoop, and posttussive vomiting
3. Convalescent- Sxs diminish, usually within 4 weeks of onset. Paroxysmal coughing may occur for months. Not contagious
117
Treatment of pertussis
● Supportive care
● Humidifiers
● Antibiotics given during catarrhal stage are most effective
○ Azithromycin or erythromycin or clarithromycin
118
Pertussis (Whooping cough) prevention
● Vaccination- acellular pertussis (Tdap vaccine)
○ Vaccination schedule?
● Treat close contacts prophylactically with antibiotics within 3 weeks of exposure
119
Influenza
● Influenza is a viral respiratory illness causing fever, cough,
headache, and malaise.
○ There are types A, B, and C
○ C causes a mild, less typical presentation.
● Can be spread by respiratory droplets, person to person contact, and fomites
○ Highly contagious
120
Influenza is considered a _____
● Seasonal epidemic-occurs annually, fall and winter
○ Caused by currently circulating Influenza A and B viruses
○ Antigenic drift- minor, progressive mutations in preexisting
combinations of antigens
121
Influenza pathophysiology
● After exposure to droplets, the incubation
period is 1-4 days
● In healthy people, viral shedding occurs
24-48 hours before the onset of symptoms
(fever, headache, myalgias, malaise)
● The virus will also affect the respiratory tractcough, sore throat, nasal discharge
● Symptoms normally improve over 2-5 days but can
last for over 1 week
122
Signs and Symptoms of Influenza:
● Sudden onset of fever
● Chills
● Body aches
● Cough
● Headache
● Sore throat
● Rhinorrhea
● GI symptoms may occur
123
Influenza diagnosis
● Clinical presentation
● Rapid antigen flu testing - more common, less sensitive
● PCR tests are sensitive and specific, but results take longer
124
Treatment for influenza:
● Supportive treatment
○ Hydration
○ Rest
○ Antipyretics
● Sometimes antivirals (Oseltamivir, Zanamivir, Baloxavir...)
○ Will shorten the duration of fever and severity of symptoms by
½ to 3 days
○ Should start within 1-2 days of symptoms
○ Treat high-risk patients
125
Antivirals for Influenza:
Neuraminidase inhibitors- Oseltamivir, Zanamivir
● Active against Influenza A and B
Oseltamivir (Tamiflu)- 75 mg PO bid for 5 days (adult)
Zanamivir (Relenza)- 2 puffs bid for 5 days
Adamantanes- Amantadine, Rimantadine
Endonuclease inhibitor- Baloxavir (Xofluza)
126
Two kinds of flu vaccines
● Inactivated influenza vaccine (IIV)
○ Can be given to pregnant women
○ Contraindication- anaphylaxis reaction to prior vaccine
● Live-attenuated influenza vaccine (LAIV)
○ May be given to healthy people ages 2 - 49 yrs old who are not
pregnant and who are not immunocompromised
127
COVID-19
● Caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
128
Pathophysiology of COVID-19
● Coronaviruses are enveloped, single-stranded RNA viruses
● SARS-CoV-2 virus primarily affects the respiratory system, although other organ systems are involved
● Patients with severe diseases were reported to have increased plasma
concentrations of proinflammatory cytokines
129
Signs and symptoms of COVID-19
● Can range from asymptomatic/mild symptoms to severe illness and
mortality
● Common symptoms:
○ Fever
○ Cough
○ Shortness of breath
130
The following symptoms may indicate COVID-19:
● Fever/chills
● Cough
● SOB/difficulty breathing
● Fatigue
● Muscle/body aches
● Headache
● New loss of taste or smell
● Sore throat
● Congestion or runny nose
● Nausea or vomiting
● Diarrhea
131
The most serious
manifestation of
COVID-19 upon initial
presentation is:
Pneumonia
132
Diagnosis of COVID-19
3 types of tests may be utilized to determine if an individual has been
infected with SARS-CoV-2
● Viral nucleic acid (RNA) detection
● Viral antigen detection
● Detection of antibodies to the virus
133
Complications of COVID-19
● Pneumonia
● Acute respiratory distress
syndrome (ARDS)
● Cardiac injury
● Arrhythmia
● Septic shock
● Liver dysfunction
● Acute kidney injury
● Multi-organ failure
134
Treatment of COVID-19
● Supportive care
● Remdesivir, an antiviral agent, was the first drug approved for
treatment of COVID-19 for hospitalized adults in October 2020
● EUAs have been issued for some vaccines, antivirals, convalescent plasma
● Dexamethasone 6 mg (IV or PO) or hydrocortisone 50 mg IV q 8 hrs for 7-10
days
