Infective Lung Disorders Flashcards
Causative agent of Pulmonary Tuberculosis
Mycobacteria tuberculosis hominis
Mode of transmission of Pulmonary Tuberculosis infection
Droplet infection
Primary pulmonary Tb
Infection in lung on 1st time entry of mycobacteria
Cells first infected in Primary pulmonary Tb
Alveolar Macrophages
Subpleural lesion seen in Primary pulmonary Tb
Ghon’s Focus
Ghon’s Complex
Ghon’s Focus + lymphatics + LN enlargement
After 3 weeks of Tb exposure
Macrophages works as APC - carry mycobacteria antigen to LN - contact with TH1 cells - activation of TH1 cell - secrets Cytokines - IFN-alpha (required for macrophages activation) - Macrophages activation - leads to Granuloma formation - Mycobacteria inactivates
Ghon’s focus
Subpleural lesion along with hilar lymph nodes enlargement
Raenke’s Complex
Fibrous ghon’s focus + calcium deposition
Simon’s focus
If immunity low in Primary pulmonary Tb - lesion forms in apical centre
Secondary pulmonary Tb can be due to
Reactivation - of prexisting mycobacteria
Reinfection - common in endemic areas
Most common cause of secondary pulmonary Tb
Reactivation
Reactivation in case of Tb is mostly seen in which condition
Occurs when immunity decreases
Elderly patients
Immunosuppressive disorders
Why apical lesion most commonly seen in secondary pulmonary Tb
Because there is maximum ventilation perfusion ratio in apical region
In case of Reactivation, individuals already sensitized for mycobacteria
Immune system rapidly recognizes mycobacteria antigen - leads to delayed type hypersensitivity
Types of hypersensitivity seen due to reactivation in case of secondary pulmonary Tb
Delayed type hypersensitivity
Delayed type hypersensitivity in secondary pulmonary Tb can leads to
Caseous necrosis
Cavitation ++
Hemoptysis - due to damage of Bronchial artery branches
If low immunity in individuals in case of secondary pulmonary Tb
No delayed type hypersensitivity - bacteria spreads through lymphatics, hematogenous and aerogenous routes
Type of Tb when bacteria spreads through Lymph nodes
Miliary Tb
Type of Tb when bacteria spreads through Lymph nodes
Miliary Tb
Mycobacteria in case of secondary Pulmonary Tb can affect which systemic organs through lymphatics or hematogenous spread
Spleen
Liver
LN
Genital organs
Type of Tb seen when bacteria spreads through aerogenous route
Endotracheal Tb
Laryngeal Tb
Clinical features of Secondary pulmonary Tb
Cough
Unexplained weight loss
Fever (evening rise of fever)
Night sweats
Hemoptysis
Anorexia
Most common source of Hemoptysis in Tuberculosis
Bronchial artery
Sometimes may be Pulmonary artery
Effect of Tuberculosis infection on Lymph nodes
2nd most common involved
Size increases
Caseous necrosis
Mating of LN (fusion)
Rich’s focus
Present in brain in case of tubercular infection
Appearance seen on CSF exam in case of tubercular meningitis
Cobweb appearance
Cardiac manifestations in case of Tuberculosis
Chronic constrictive pericarditis
Most common cause of Chronic constrictive pericarditis in India
Tuberculosis
Which bones are most commonly involved in Tuberculosis infection
Vertebral column - Spinal tuberculosis or Pott’s spine
Kidney related manifestations in Tuberculosis infection
Tubercular pyelonephritis
Pus cell in urine (Pyuria)
Adrenal gland manifestations in case of Tuberculosis
Can lead to Chronic adrenal insufficiency
Most common cause of Chronic adrenal insufficiency in india
Tubercular adrenalitis
Autoimmune adrenalitis
Male Genital tract involvement in Tb
Involves 1st epididymis and then involves testicular tissue
Female genital tract involvement in Tb
Involvement of fallopian tube - Decreases fertility
Focus seen in liver in case of Tb
Simmond’s focus
Focus seen in Pulmonary vein in case of Tb
Weigart focus
Involvement of ear in Tb
Tubercular otitis media - multiple perforations in tympanic membrane
Eye involvement in Tb
Phlectenular conjunctivitis (Type 4 HR) - associated with delayed type HR
Diagnostic methods of Tuberculosis
ESR
Lymphocytosis
Sputum examination - Stain, Culture, PCR - CBNAAT
Chest X ray
CT scan
Sputum sample in case of Tb is usually taken at which time
Early morning
Findings on staining method in Tb
Mycolic acid - acid fast appearance - Pink colored mycobacteria in Bluish background can be seen
Gold standard diagnostic method for Tb
Bacterial culture
Bacterial culture can be done on which media in Tb
Lobstein Jenson media
Takes time
Bactec media - needs>10,000 bac.
Decontamination method used for sputum in case of Tb
Petroff’s method
NALC method
Full form of CBNAAT
Cartridge based nucleic acid amplification test
X ray findings in case of Tb
Tubercular focus+
Pleural effusion - On pleural tap - Straw colored fluid, increased adenosine deaminase
MDR-TB full form
Multidrug resistance Tb
MDR-TB therapy given to patients who are resistant to
Isoniazid/Rifampicin resistant
XDR-TB full form
Extensively drug resistant Tb
XDR -TB therapy is resistant to
Resistance to 1st line drugs
Aminoglycosides
Injectable fluoroquinolones
Pneumonia
Inflammation and infection of lung parenchyma
Classification of pneumonia
Typical Pneumonia (Air space Pneumonia)
Atypical Pneumonia (Interstitial Pneumonia)
Most common cause of Typical Pneumonia
Bacterial infection
Characteristics findings of Typical Pneumonia
Presence of alveolar exudates (M.I)
Neutrophilic infiltration
Most common causes of Atypical Pneumonia
Mostly non bacterial in nature
Infiltration seen in Atypical Pneumonia
Involvement of Interstitial spaces
Macrophages/lymphocytes infiltration
Laennec stages of Typical Pneumonia
Congestion
Red hepatization
Gray hepatization
Resolution
Congestion stage of Typical Pneumonia
1-2 days
Blood vessels dilatation
Fluid in alveoli (bacteria +, WBC +++)
Red hepatization stage of Typical Pneumonia
3-4 days
Fluid in alveoli - WBC + , RBC +++
Lungs consistency decreases - Liver like consistency (hepatization)
Fibrin +
Gray hepatization stage of Typical Pneumonia
5-8 days
RBC breakdown
Fibrin deposition +++ - color changes to gray
Resolution stage of Typical Pneumonia
More than 8 days
Phagocytosis of causative organism by WBC
Lobar pneumonia
S. Pneumoniae
Whole lobe involvement
Bronchopneumonia
Smaller airways
Patchy involvement
Seen in childrens and adzlts
Basal/bilateral
Clinical features of Typical Pneumonia
Fever with chills
Cough with sputum
Dyspnea
Pain on deep inspiration
Clinical features of Atypical Pneumonia
Also termed as Walking pneumonia
Fever
Cough - dry cough
Mild dyspnea
Organisms associated with Typical Pneumonia
Streptococcus pneumoniae
Staphylococcus aureus
Klebsiella
H. Influenza
Pseudomonas aeruginosa
Most common cause of community acquired pneumonia
S. Pneumoniae
Staph aureus in Pneumonia
Associated with secondary pneumonia
Abscess formation
Sputum in case of pneumonia caused by Klebsiella
Red currant jelly sputum
Bacteria most commonly responsible for pneumonia on aspiration
Klebsiella
Most common bacterial cause of COPD exacerbations
H. Influenza - capsulated organism
Vaccine for Type ‘b’ H influenza
Hib Vaccine
Which organism most commonly causes pneumonia in immunocompromised individuals
Pseudomonas aeruginosa
Most common cause in Nosocomial and ventilator associated pneumonia
Pseudomonas aeruginosa
Organisms associated with Atypical Pneumonia
Mycoplasma pneumoniae
Chlamydia
Pneumocystis jiroveci
Coxiella brunetti
Legionella
Most common cause of Atypical Pneumonia
Mycoplasma pneumoniae
2nd most common cause of Atypical Pneumonia
Chlamydia
Fungus responsible for Atypical Pneumonia
Pneumocystis jiroveci
Affects immunocompromised individuals (AIDS)
Cause of Q fever
Coxiella brunetti
Legionella
Air loving organismd
ICU admitted patient + immunocompromised
History of post transplant
Pontiac fever is caused by
Legionella
Viruses responsible for Atypical Pneumonia
Influenza type A
Respiratory syncytial virus(RSV)
Measles
CMV
Adult respiratory syndrome can also be termed as
Shock lung
Stiff lung
Hyelin membrane disease (HMD)
Non cardiac Pulmonary edema
Findings of Adult respiratory distress syndrome
Acute respiratory failure within 1 week
+ Radiographically bilateral pulmonary opacities
Direct risk factors of ARDS
Direct injury to lungs
Pneumonia
Gastric aspiration
Inhaled gas
Overall most common cause of ARDS
Pneumonia
Initiation point in pathogenesis of ARDS
Endothelial cell injury - release Cytokines - IL-8 - neutrophils accumulation - damages alveolar epithelial cells - surfactants decreases - surface tension increases - leads to alveolar collapse
Also release of Cytokines - leads to increase in permeability - leak out of protein rich fluid - protein rich fluid makes barrier - formation of hyelin membrane - decreased elasticity of lung - stiff lung
Clinical features of ARDS
Respiratory distress - Hypoxemia - Multiple organ dysfunction syndrome - Death
Diagnosis of ARDS
Chest X ray
Pulmonary capillary wedge pressure (PCWP)
Finding of chest x ray in ARDS
Bilateral Pulmonary opacities (Whitish appearance) - “White-out lung”
Treatment of ARDS
O2 - Refractory
Targets primary cause - If pneumonia treat it
PEEP Ventilation (Positive End expiratory pressure ventilation)
Steroids
Cause of Neonatal respiratory distress syndrome
Surfactants deficiency
Stimulatory effect of which hormones on surfactants production
Cortisol
Thyroxine
Inhibitory effect of which hormone on Surfactants production
Insulin
Surfactants are secreted from
Type 2 Pneumocytes
Surfactants secretion starts from which week of gestation
From 28th week of gestation
Secretion of Surfactants peaks in which week of gestation
33-34th week
Chemical composition of Surfactants
Lecithin - Dilpalmityl phosphatidyl choline (DPPC)
Function of Surfactants
Decreases surface tension - increased alveolar collapse tendency
Surfactants reduces alveolar collapse tendency
Etiology of Neonatal respiratory distress Syndrome
Premature baby (M.C cause)
C-section
Maternal diabetes - maternal hyperglycemia - fetal Hyperglycemia - fetal pancreas stimulation - insulin secretion increases - Surfactants inhibition
Clinical features of Neonatal respiratory distress Syndrome
Onset of respiratory distress within few hours of birth
Tachypnea
Hypoxemia
Diagnosis of NRDS
Lecithin : Singomyelin ratio - L:S ratio in amniotic fluid
Chest X ray
Normal L:S ratio
> 2:1
If L:S ratio <2:1
High chances of NRDS
X ray finding in NRDS
White -out lung
Ground glass opacity
Complications of NRDS
Decreased O2 in blood - Patent ductus arteriosus
Intestine - gut mucosa injury - Necrotizing enterocolitis
Treatment of NRDS
Surfactants for lung maturity - Intratracheal administration of Surfactants
O2 therapy - Endotracheal tube
Steroids to mother if risk of premature baby - increases no. Of Surfactants in baby
Indirect risk factors of ARDS
Sepsis
Mechanical Trauma
TRALI(Transfusion related acute lung injury)
DIC
Fat embolism
Drugs - Barbiturates
Pancreatitis
Burns
