HUMAN DISEASES
Exam questions Dubois = 3 open question and 10 statements with correction.
1. LUNG DISEASES (DUBOIS)
Obstructive lung disease (OLD) is a respiratory disease characterized by airway obstruction by (1) inflamed and
easily collapsible airways, (2) Obstruction to airflow & (3) Frequent office visits and hospitalization. Diagnosis
requires several factors depending on type, but common characteristic is decreased FEV1/FVC (forces expiratory
volume in 1 sec/ forced vital capacity) ratio (ability to exhale 70% of their breath in 1 second).
Restrictive lung disease (RLD) can be categorized in extrapulmonary, pleural, or parenchymal respiratory diseases
that = Restrict lung expansion result in decreased lung volume, Increased work of breathing & inadequate
ventilation/oxygenation. Pulmonary function test show = FVC ↓, FEV1 ↓, FEV1/FVC ≈ normal & TLC < 80% expected
value.
EX.V. Spirometry volumes = VT (tidal volume)= take a normal
breath in; IRV (inspiratory reserve volume)= maximal inspiration
of air; ERV (expiratory reserve volume)= maximal expiration of
air; VC (vital capacity)= VT+IRV+ERV; RV (residual volume)=
volume that is not used in the lung; TLC (total lung capacity)=
total air capacity of the lung.
Difference between OLD and RLD in spirometry
➔ OLD: more difficult to exhale so lowest level of ERV will
be higher (at baseline) and after a while to compensate
the IRV will be higher as well.
➔ RLD: all the lung volumes are brought down to a lower
volume = baseline is lower, maximal inspiratory capacity
is lower, max. expiratory capacity is somewhat lower &
TLC and VC are smaller.
LUNG DISEASES AFFECTING THE AIRWAYS
ASTHMA
= Increased sensitivity and hyperresponsiveness of bronchial tubes → inflamed and thickened bronchial walls and
during an asthma attack also tightened smooth muscles and air trapped in alveoli.
- Asthma triggers = smoke, stress, dust, cold air, anger, pets, exercise, pollen, pollution, infections, ….
- Asthma symptoms = frequently coughing, shortness of breath, feeling tired, wheezing, common cold,
allergies, trouble while sleeping and chest pain.
- Asthma diagnosis = variable degree of airway obstruction using a peak-flow meter or spirometry (→
severity, reversibility & variability of disease)
- Asthma treatment scheme = avoiding triggers and education is key! Topical treatment through inhalers
using short-acting beta2-agonist on demand. If the inflammation or disease is more severe also
corticosteroids are given but in even more advanced cases systemic treatment may be necessary.
CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
= A progressive disease affecting the lungs and the ability to breathe. Airflow limitation is not fully reversible. Flow
in and out lungs is impaired. Measured with peak flow meter or spirometry
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,HUMAN DISEASES
Classification of COPD in chronic
bronchitis and emphysema. Both
conditions can coexist in varying degrees.
Main cause = cigarette smoking (20 pack-
years), less often: gases or small particles.
α 1-antitrypsin deficiency: genetic
condition resulting in COPD.
- Parameters increase in airway
resistance = FEV1 ↓, FEV1/FVC <
0.7, RV ↑, TLC ↑ (hyperinflation,
barrel chest) & VC = normal →
measured via spirometry & chest
X-ray and CT scan (emphysema).
- COPD treatment = Inhaled bronchodilators, Inhaled corticosteroids, Oxygen supplementation, Systemic
corticosteroids, Smoking cessation!, Pulmonary rehabilitation programs, Emphysema lung reduction
surgery OR Lung Tx
ACUTE BRONCHITIS
= short term infection caused by infections or lung
irritants, viruses or bacteria (secondary infection).
Symptoms are hacking cough and phlegm production,
fever, fatigue & chest discomfort. R/ antipyretics,
antitussives, fluids and humidfication, (AB).
CYSTIC FIBROSIS
= CF = autosomal recessive disorder that
affects mostly the lungs, but also the
pancreas, liver, kidneys, and intestine. Long-
term issues include difficulty breathing and
coughing up mucus as a result of frequent lung
infections. It is caused by the presence of
mutations in both copies of the gene for the
cystic fibrosis transmembrane conductance
regulator (CFTR) protein. When the CFTR is not
functional, secretions which are usually thin
instead become thick. The condition is
diagnosed by a sweat test and genetic testing.
LUNG DISEASES AFFECTING THE AIR SACS (ALVEOLI)
PNEUMONIA
= infection of the lower respiratory tract and the alveoli. Causative agents are most likely bacteria, viruses (e.g.
influenza, covid-19).
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,HUMAN DISEASES
Pathophysiology = Aspiration of limited number of
virulent or higher volume of less virulent organisms.
Spread can be hematogeous (endocarditis, septic
trombophlebitis, …) OR by inhalation. Consequence = host
response that creates an acute imflammatory reaction.
Starts with a local inflammation by filled alveoli, disturbed
gas exchange, shunt resulting in hypoxia, most often
without hypercapnia. SIRS (systemic inflammatory
response syndrome) is a more generalised response,
eventually leading to sepsis/septic shock.
There are distinct classifications depending on causative
microorganisms (+/- resistance), diagnosis and treatment.
➔ Community acquired pneumonia (CAP) (outside
hospital)
➔ Nosocomial pneumonia: health care or hospital
acquired pneumonia
MOST COMMON ETIOLOGIES OF CAP
- Streptococcus pneumoniae = most frequent, and particularly with smoking, alcohol, age (extremes),
immunosuppression (Tx, HIV), asplenic, chronis diseases (DM,CRRF,COPD, HF). Classical presentation is
lobar pneumonia but other presentations are possible. Diagnosed by culturing sputum/pleural fluid/blood.
- Mycoplasma pneumoniae = epidemic presentation (family), can occur in healthy/older children/young
adults and is characterised as “atypical pneumonia”: less abrupt, less “respiratory” symptoms. Diagnosed
using serology/PCR.
DIAGNOSIS
- Diagnosis of pneumonia: Clinical signs and symptoms (fever, hemodynamic state), Chest X-ray & CT scan
- Causative agent: Microscopic examination and culture of sputum and blood/ Serology (Mycoplasma,
Chlamydophila)/ Antigen detection (Legionella)
- Severity? clinical presentation, comorbidity → In- or out of hospital treatment/ Treatment is different in
immunocompromised
CAP TREATMENT
- Supportive care: eventually oxygen
- Antibiotics directed to Streptococcus pneumonia → Penicilline resistency! (not in Belgium), evt
fluoroquinolones. Eventually also “atypical microorganisms to be treated (depending on clinical picture):
neomacrolides or fluoroquinolones
- Treatment of complications: Septic shock & Empyema: chest drain
TUBERCULOSIS
Infectious airborne disease that commonly affects the lungs and is caused by bacteria: Mycobacterium
tuberculosis-complex.
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, HUMAN DISEASES
Epidemiology TBC = initially declining since WW2,
recently new increase worldwide caused by insufficient
TB control programs, increasing prevalence HIV and
refugees. 1% of the world population is contaminated
per year with 1/3 has been contaminated.
Pathophysiology = figures!
Possible consequences of pulmonary tuberculosis are reolution & absorption are disturbed by fibros encapsulation
& calcification resulting in primary pulmonary tuberculosis which can result in lymphatic dissemination,
hematogenous dissemination and bronchial dissemination. There are 3 types of TBC lesions = latent infection,
cavitary tuberculosis (cavities in the lung) & miliary tuberculosis (many small lesions in the lung and hematogenous
spread/dissemination everywhere else in the body)).
Symptoms are most often atypical like general fatigue, weight loss, fever, night sweat; some are typical like cough,
back pain and shortness of breath.
Scans of the lungs can show pulmonary cavities which are highly
infective (so isolation!), scans of the pleura can show lymfocytic
pleuritis this can lead to fibrosis that will cause restrictive lung
function. You can also have tuberculosis of the glands with often a
liquefication (necrotic core) with perforation to skin. Tuberculosis
of the bone can occur in axial bones preferably with sometimes
leading to large “cold abscesses” along vertebral column in psoas
muscle. CNS tuberculosis or tuberculous meningitis (most frequent one). Also possible in GI tract, genitourinary
tract, pericardium (causes pericardial tamponade) → fluid accumulation due to tuberculosis.
Diagnosis = Clinical picture + proof of bacteria → Acid-fast bacils on dedicated stains (Ziehl, auramin), Culture on
dedicated media (eg Löwenstein), PCR techniques & Histopathology: granulomas, preferably caseating. Also a
possible diagnostic tool is the skintest for screening and epidemiology: tuberculin intradermal test (= in vivo) and
more recently in-vitro: IFN-gamma release assays (IGRA).
Treatment of TBC = combination of 4 AB for a couple of months and then reduced to 2 AB for at least 6 months →
prolonged treatment.
EMPHYSEMA: RESULTING FROM DAMAGE TO FRAGILE CONNECTIONS BETWEEN ALVEOLI
PULMONARY EDEME (NOT FROM INFLAMMATORY/INFECTIOUS RESPONSE)
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