Respiratory Tract Infections Flashcards
What are the 5 types of upper respiratory tract infections?
- Infective rhinitis (common cold)
- Influenza
- Pharyngitis (sore throat)
- Laryngitis
- Acute laryngotracheo-bronchitis (croup)
What are the 4 types of lower respiratory tract infections?
- Influenza
- Pertussis (whooping cough)
- Tuberculosis
- Pneumonia
What are the divisions of the upper and lower respiratory tracts?
Larynx & above: upper
Trachea & below: lower
Describe infective rhinitis
Common cold (URTI)
- caused by many viruses
- virus infects nasal epithelium and causes inflammatory reaction
SSX:
- gradual onset
- rhinorrhea
- mild cold SSX
Describe pharyngitis
Sore throat (URTI)
- usually viral (adenovirus or influenza)
- sometimes bacterial (strep)
SSX:
- sore throat
- Cx lymphadenopathy
- maybe pain and aches
- bacterial: mucoprurulent discharge
Describe laryngotracheo-bronchitis
Croup (URTI)
Viral (influenza, parainfluenza, RSV in children)
Virus destroys epithelial cells, inflammatory reaction reduces lumen of airways
SSX:
- barking cough becoming nocturnal
- inspiratory stridor
- cold SSX
Emergency SSX:
- cyanosis
- pallor
Common in young children 3 mths - 6 years
Describe pertussis
Whooping cough (LRTI)
Viral (bordetella pertussis)
Virus colonizes LRT epithelium, inhibiting immune response and paralyzing cilia (mucus buildup)
SSX: Stage 1 (Inflammatory) - hacking night cough becoming diurnal
Stage 2 (Paroxysmal) - paroxysms of coughing followed by whoop
Stage 3 (Convalescent)
Highly contagious notifiable disease
Describe tuberculosis
TB / Consumption (LRTI)
Viral (mycobacterium tuberculosis)
Primary:
- TB causes caseous necrosis & granuloma formation (primary lesions)
Progressive Primary:
- lesions become active
- miliary TB
Secondary:
- new infection
- reactivation of lesions without miliary TB
Progressive Secondary
- lesions active
- miliary TB
Notifiable disease
Long latency period
Often asymptomatic
Describe pneumonia
Any condition involving inflammation of lung tissue
Viral / bacterial / aspiration
Classifications:
Typical (strep / staph)
Atypical (legionairre’s, mycoplasma / walking, viral)
Consolidation:
- lung tissue fills with fluid
- causes swelling / hardening of lung tissue, decreases compliance of lungs, decreases tidal volume, decreased gaseous exchange at respiratory membrane
SSX (typical):
- fever
- pain
- tachycardia
- facial flushing
- dry cough becoming productive
- dyspnoea
- tachypnoea
Signs (typical):
- dull percussion (consolidation)
- increased vocal resonance
- crepitations
- pleural rub
- high pitched bronchial sounds
Describe influenza
Can affect the upper or lower respiratory tract
Viral (influenza A, B, C)
Virus enters respiratory epithelium & replicates viral cells, causing cell necrosis & desquamation of respiratory tract
SSX:
- acute onset
- fever and chills
- aches and pains
- fatigue
- maybe nausea, vomiting
Contagious
Virus mutates so vaccine not lasting
How is infective rhinitis spread?
Secretions (hands, coughing, sneezing)
What are the key differences between infective rhinitis and influenza?
Pathology:
- influenza causes cell necrosis and desquamation of the respiratory tract, and can therefore be fatal
- influenza virus enters respiratory epithelium and causes epithelial cells to replicate viral host cells
SSX:
- influenza: acute onset
- SSX much more severe in influenza
Is viral or bacterial pharyngitis more common? And which viruses and bacteria can cause pharyngitis?
Viral more common:
- adenovirus, influenza
- Epstein Barr (EBV)
Bacterial less common:
- strep
- pertussis (whooping cough)
- diptheria, gonorrhea, clamydia
What are the observable differences between croup and whooping cough?
Croup:
- URTI
- cough begins diurnal and then becomes nocturnal
- cough barking but doesn’t occur in paroxysms
- inspiratory stridor, but not in the pattern of a ‘whoop’ following paroxysmal coughing
Whooping Cough / pertussis:
- LRTI
- cough begins nocturnal then becomes diurnal
- paroxysms of coughing followed by an inspiratory ‘whoop’ (key observable pattern)
Whooping cough a notifiable disease: highly contagious with an incubation period of 7-17 days
What are signs warranting emergency referral in croup?
- intercostal retraction
- cyanosis
- pallor
- stridor at rest
- extreme lethargy
What are the 3 stages of pertussis?
- inflammatory
- insidious onset of symptoms - paroxysmal
- nature of cough changes to distinctive paroxysms / whoop pattern - convalescent
How does bordetella pertussis (B pertussis) affect the body in pertussis / whooping cough?
- colonizes lower respiratory tract epithelium
- inhibits neutrophils and macrophages from performing immune function
- paralyzes cilia
What are causes of aspiration pneumonia?
inflammation secondary to entry to the lungs of food, fluid, vomit
What are the different types of typical and atypical pneumonia?
Typical (bacterial) - caused by strep, staph
Atypical
- mycoplasma (walking)
- legionella
- viral (influenza, parainfluenza, RSV)
What are the 4 clinical signs of pneumonia?
- Percussion: dull in affected area
- Tactile fremitus: increased in affected area
- Auscultation: pleural friction, bronchial breath sounds, crackles
- Unilateral reduction in Tx cage expansion
Briefly describe the 3 atypical pneumonias:
- Myocplasma
- walking pneumonia
- few respiratory SSX
- mild fever, malaise - Legionella / Legionnaire’s
- sudden onset
- fever, malaise
- abdo pain, diarrhea
- productive cough, pleuritic pain
(virus associated with watery environments) - Viral
- fever first symptom
- mild respiratory SSX after a few days
- self limiting < 10 days
Describe the pathophysiology of primary TB
- TB microbe inhaled and settles in upper lobe of lungs
2. formation of granulomatous Ghon’s lesions is body’s immune response to limit spread of TB
What causes TB to progress to miliary TB?
The spread of TB through the blood stream (enters bloodstream via pulmonary veins)
What is a Ghon’s lesion and a Ghon complex?
Ghon’s lesion:
- granuloma with a caseous necrotic core that may calcify
- found in the foci of TB tubercles, in the bottom of upper lobes, or top of lower lobes
Ghon complex
- a Ghon’s lesion that also includes a mediastinal or hilar lymph node
