Upper and Lower Respiratory infections

Lobna Al AL JuffaliSpring 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: Difficultybreathing. 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 influenzavirus 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,ChlamydiaViral 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 walls

No exudatesNo consolidation

Patchy 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

2. Red hepatizationNext 48 hrs

• The lung becomes red • As RBCS, fibrin, and PMN leukocytes fill

the alveoli.

3.Gray hepatization3-8 days

• Lung become gray as the leukocytes and fibrin consolidate in the involved alveoli

4.Resolution7-11days

• Exudate is lysed and resorbed by macrophages, restoring the tissue to its original structure

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