lobna al al juffali fall 2010. upper respiratory tract ◦ nose, oropharynx, and larynx lower...
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Upper and Lower Respiratory infections
Lobna Al AL JuffaliFall 2010
Respiratory system
Areas Involved in Respiratory Tract Infections Upper respiratory tract
◦ Nose, oropharynx, and larynx Lower respiratory tract
◦ Lower airways and lungs Upper and lower airways
Nose Pharynx Larynx (speech) Trachea Bronchi and their smaller branches lungs
Alveoli Gas exchange
Anatomy of the Respiratory system
Passageways that allow air to reach the lungs
1. Purify2. Humidify3. Warm incoming air
The major function of the respiratory system is to supply the body with oxygen and to dispose of carbon dioxide.
Functions of the respiratory system
Hypoxia: Decreased levels of oxygen in the tissues.
Hypoxemia: Decreased levels of oxygen in arterial blood.
Hypercapnia: Increased levels of CO2 in the blood.
Hypocapnia: Decreased levels of CO2 in the blood.
Dyspnea: Difficulty breathing.
Tachypnea: Rapid rate of breathing.
Cyanosis: Bluish discoloration of skin and mucous membranes due to poor oxygenation of the blood.
Hemoptysis: Blood in the sputum.
General Symptoms of Respiratory Disease
Upper Respiratory infection
PHARYNGITIS Pharyngitis is an acute infection of the
oropharynx or nasopharynx that results in 1% to 2% of all outpatient visits.
The incubation period is 2 to 5 days, and the illness often occurs in clusters
PHARYNGITIS
viral causes are most commonrhinovirus, coronavirus, and adenovirus causes ACUTE Pharyngitis
BacterialGroup A β-hemolytic Streptococcus 15% to 30% Streptococcus pyogenes
Pathopyisiology bacteria or viruses may directly invade the
pharyngeal mucosa, causing a local inflammatory response.
rhinovirus and coronavirus, can cause irritation of pharyngeal mucosa secondary to nasal secretions.
Streptococcal infections are characterized by local invasion and release of extracellular toxins and proteases.
Complications of pharyngitis with Group A Streptococcus acute rheumatic fever acute glomerulonephritis reactive arthritis may occur as a result.
CLINICAL PRESENTATION
Signs and symptoms A sore throat of sudden onset that is mostly self-
limited
Pain on swallowing.
Fever.
Headache, nausea, vomiting, and abdominal pain (especially children).
CLINICAL PRESENTATION
Erythema/inflammation of the tonsils and pharynx with or without patchy exudates.
Enlarged, tender lymph nodes.
Red swollen uvula, petechiae on the soft palate
Several symptoms that are not suggestive of Group A are cough, conjunctivitis, and diarrhea.
Laboratory tests
StreptococcusThroat swab and culture or rapid antigen detection testing
Rhinitis and Sinusitis
Rhinitis ◦ Inflammation of the nasal mucosa
Sinusitis ◦ Inflammation of the paranasal sinuses
that persists beyond 7–14 days
Chronic/recurrent infections occur three to four times a year and are unresponsive to steam and decongestants.
Classifications of Rhinosinusitis
Acute rhinosinusitis ◦ May be of viral, bacterial, or mixed viral-bacterial
origin ◦ May last from 5 to 7 days up to 4 weeks
Subacute rhinosinusitis ◦ Lasts from 4 weeks to less than 12 weeks
Chronic rhinosinusitis ◦ Lasts beyond 12 weeks
Allergic Rhinosinusitis
Occurrence ◦ Occurs in conjunction with allergic rhinitis◦ Mucosal changes are the same as allergic rhinitis
Symptoms◦ Nasal stuffiness, itching and burning of the nose, frequent
bouts of sneezing, recurrent frontal headache, watery nasal discharge
Treatment◦ Oral antihistamines, nasal decongestants, and intranasal
cromolyn
SINUSITIS
Bacterial
Acute-disease lasts less than 30 days with complete resolution of symptoms-S. Pneumoniae and H. influenzae
Chronic -episodes of inflammation lasting more than 3 months with persistence of respiratory symptoms. -Polymicrobial- anaerobes -gram-negative bacilli -fungi
viral
Signs and symptoms condition
•Nasal discharge/congestion. •Maxillary tooth pain,• facial or sinus pain that may radiate (unilateral in particular) as well as deterioration after initial improvement.• Severe or persistent (beyond 7 days) signs and symptoms are most likely bacterial and should be treated with antimicrobials.
AcuteAdults:
•Nasal discharge and cough for greater than 10–14 days•temperature 39°C (102.2°F)• facial swelling •pain
Children:
•are similar to those of acute sinusitis but more nonspecific.• Rhinorrhea is associated with acute exacerbations. •Chronic unproductive cough, laryngitis, and headache may occur.
Chronic Symptoms
The common cold is a viral infection of your upper respiratory tract .
more than 200 viruses can cause a common cold, symptoms tend to vary greatly.
Most adults are likely to have a common cold two to four times a year.
Children 6-10 times a year. Most people recover from a common cold in about a week or two.
Common cold
Is a viral infection that can affect the upper or lower respiratory tract.
influenza season usually runs from November to April Three distinct forms of influenza virus have been identified: A, B and C. Of these three variants, type A is the most common
and causes the most serious illness. The influenza virus is a highly transmissible
respiratory pathogen. Because the organism has a high tendency for genetic mutation, new variants of the virus are constantly arising in different places around the world.
Influenza
Influenza infection can cause marked Inflammation of the respiratory epithelium leading to acute tissue damage and a loss of ciliated cells that protect the respiratory passages from other organisms.
As a result, influenza infection may lead to co-infection of the respiratory passages with bacteria.
It is also possible for the influenza virus to infect the tissues of the lung itself to cause a viral pneumonia.
Influenza
cold influenza
gradual sudden onset
rare Charecteristic , high >38˚C 3-4 days duration
fever
hacking Dry cough
rare prominent headache
slight Usual ; often severe myalgia (muscle aches/pains)
Very mild Can last up to 2-3 weeks Tiredness and weakness
never Early prominent Extreme exhaustion
Mild to moderate common Chest discomfort
common sometimes Stuffy nose
usual sometimes Sneezing
common sometimes Sore throat
Differentiating the symptoms of cold and influenza
Lower respiratory infection
Pneumonia is the most common cause of death due to infectious disease
Seventh most common cause of death in the USA
Hospital acquired Pneumonia is the second most common nosocomial infection(0.6%-1.1%)
Mortality rates are CAP without hospitalization 1% CAP with hospitalization about 14% Nosocomial about 33-50%
Pneumonia
Pneumonia approximately three million cases are diagnosed
annually at a cost of more than $20 billion to the healthcare system.
Pneumonia occurs throughout the year, with the relative prevalence of disease resulting from different etiologic agents varying with the seasons.
It occurs in persons of all ages
clinical manifestations are most severe in the very young, the elderly, and the chronically ill.
Pneumonia
Hospital Acquired Pneumonia
Ventilator Hospital acquired Health care
Community Acquired
Pneumonia
The environmental setting in which it developed:
Pneumonia(depending on
the type of organism
Typical S. pneumoniae, H. influenzae,
Staphylococcus aureus, and enteric Gram-negative bacteria
Atypical Mycoplasma, Legionella,Chlamydia
Viral and TB
inhaled as aerosolized
particles
via the bloodstream from
an extrapulmonary site of infection
aspiration of oropharyngeal contents may
occur .
Microorganisms gain access to the lower respiratory tract by three routes:
1.Mechanical Epithelial cells are covered with beating cilia
blanketed by a layer of mucus. Each cell has about 200 cilia that beat up to 500
times/min, moving the mucus layer upward toward the larynx.
The mucus itself contains antimicrobial compounds such as lysozyme and secretory IgA antibodies.
the cough reflex to clear aspirated material
Host defense mechanisms
2.Cellualr Bacteria that reach the terminal
bronchioles, alveolar ducts, and alveoli are inactivated primarily by alveolar macrophages and neutrophils.
3.Humoral Opsonization of the microorganism by
complement and antibodies enhances phagocytosis by these cells.
Host defense mechanisms
Depends on the etiologic agent
Pathological Picture
Bacterial An intraalveolar
suppurative exudate with consolidationLobar pneumonia
bronchopneumonia
Viral or Mycoplasma pneumonia An interstial inflammation with accumulation of an infiltrate in the alveolar wallsNo exudatesNo consolidation
FungalPatchy distribution of
granulomasWhich undergo caseous
necrosis with the development of
cavaties
Age >65 Aspiration of oropharyngeal secretions Viral respiratory infections Chronic illness and debilitation Chronic respiratory
disease(COPD,astha,cystic fibrosis) Cancer Prolonged bedrest Tracheastomy or endotracheal tube
Risk factors for pneumonia
Abdominal thoracic surgery Rib fractures Immunosuppressive therapy AIDS Smocking history Alcoholism malnutrition
Risk factors for pneumonia
Acute Infection of the pulmonary parenchyma accompanied by the presence of an acute infiltrate on chest radiograph or ausculatory findings consistent with pneumonia . in patients who are not hospitalized or in a long –term care facility for 14 days or more before symptoms appear
Community Acquired Pneumonia CAP
Microbiology of community acquired pneumonia
Microbiology
S. pneumoniae H. Influenzae S. aures Gram –ve bacilli Legionella species M. Pneumoniae viralNo diagnosis
Pneumococci reachs the alveoli in droplets of mucus or saliva.
The lower lobes of the lungs are frequently involved because of the effect of gravity.
Pneumococcal pneumonia
Pneumococcus in the alveoli
• Serious exudates Pours into the alveoli from the dilated ,leaking blood vessels
1.Engorgement (4-12 hrs)
• The lung becomes red • As RBCS, fibrin, and PMN leukocytes fill the
alveoli.2. Red hepatizationNext 48 hrs
• Lung become gray as the leukocytes and fibrin consolidate in the involved alveoli3.Gray hepatization
3-8 days
• Exudate is lysed and resorbed by macrophages, restoring the tissue to its original structure
4.Resolution7-11days
Sudden Chills ,fever Pleuritic pain Cough Rust colored sputum Hypoxemia As a result of shunting of blood through the
non ventilated, consolidated area of lung
Clinical presentation
Consolidation Pleural Effusion
Plural effusions Death
chronically ill elderly Bacteremia which leads to ( endocarditis, meningitis and
peritonitis)
Complications
Chest radiograph Dense lobar or segmental infiltrate
Laboratory examination Leukocytosis with a predominance of polymorphonuclear cells
Sputum examination (gross appearance ,microscopic examination and culture)
Blood culture
Should be done in certain high risk patients (e.g. sever CAP, chronic liver disease).
Low oxygen saturation on arterial blood gas or pulse oximetry
Diagnostic test
HAP: Pneumonia that occurs 48 hrs or more after admission Which was not incubating at the time of admission
Ventilator- associated Pneumonia that arises more then 48-72 hrs after endotracheal intubation
Hospital Aquired Pneumonia HAP
Health care associated Pneumonia: pneumonia developing in a patient who is hospitalized in an acute care hospital for 2 or
more days within 90 days of the infection; resides in a nursing home or along-term facility received recent IV AB therapy, chemotherapy, or wound care within the past 30
days of the current infection ; or attended a hospital or hemodialysis clinic
Hospital Aquired Pneumonia HAP
Gram-negitive bacilliPseudomonas aeruginosa Acinetobacter Spp.Enterobacter Spp.
ViralCytomegalovirusInfluenzaRespiratory syncytial virusFungiAspergillus
Microorganisms
Gram-negitive bacilli
S. Aures
Anarobic bacteria
H. Influenzae
S. Pneumoniae
Legionella
Viral Fungi
Cause extensive damage to the lung parenchyma
Complications such as lung abscess and emphysema
Mortality is high 33%
Complications of HAP
1. Intubation and mechanical ventilation2. Supine patient position 3. Enteral feeding4. pharyngeal colonization5. Stress bleeding prophylaxis6. Blood transfusion7. Hyperglycemia
Risk factors for Hospital-acquired pneumonia
8. Immunosuppression/corticosteriods9. Surgical procedures :thoracoabdominal,
upperabdominal ,thoracic10. Immobilization11. Nasogastric tubes12. Prior antibiotic therapy13. Admission to ICU14. Elderly15. Underlying chronic lung disease
Risk factors for Hospital-acquired pneumonia
Aspiration pnemonia Pathological consequences of the entery of oropharyngeal
secretions,particulate matter,or gastric contents into the lower airway.
Colonization of oropharynx and gastric plays a critical role in aspiration pneumonia.
GM-ve organisms within 48 hrs of hospitalization
Aspiration of orophyrngeal secretions occurs during sleep and is enhanced by
1. nasogastric tube2. Altered consciousness3. Depressed gag reflex4. Delayed gastric emptying
Bacterial counts rise Sucrulfate is a medication that heals ulcer
without altering the gastric pH.
What happens when patients take medications that raise the gastric pH? (H2 blockers)
Aspiration pneumoni
a
Aspiration of particulate
matter
Mendelson’s
pneumonia
Anaerobic pneumoni
a
Aspiration of oropharyngeal secretions containing anerobes
Such as Bacteroids, Fusobacterium, Peptococcus,and Peptostreptococcus species.
Common among patient with poor hygieneand chronic alcoholism
Onset of symptoms 1-2 weeks Most distinguish symptom is productive cough of
foul- smelling sputum
Anaerobic pneumonia
Related to the regurgitation and aspiration of the acidic stomach contents.
May lead to sudden death (obstruction)
It follows three patterns1. Rapid recovery (small amount or alkaline)2. Rapid development of acute respiratory distress
syndrome3. Bacterial superinfection
Mendelson’s Pneumonia
Aspiration of particulate matter
If the object is lodged high in the trachea complete obstruction ,apnea, aphonia and rapid death
If the object is lodged in smaller airways
Chronic cough And recurrent
infections
Atypical pneumonia refers to pneumonia caused by certain bacteria - namely, Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae or virsus.
atypical pneumonias are commonly associated with milder forms of pneumonia, pneumonia due to Legionella, in particular, can be quite severe and lead to high mortality rates.
Symptoms Confusion (especially with Legionella pneumonia) Diarrhea (especially with Legionella pneumonia) Muscle stiffness and aching , Rash (especially with
mycoplasma pneumonia)
Atypical Pneumonia