Tuesday, February 26, 2013

ACUTE VIRAL UPPER RESPIRATORY TRACT INFECTIONS




Acute Viral Upper Respiratory Tract Infections – is a large group of infectious diseases,
which are caused by viruses, transmitted by droplet way, characterized by intoxication and catarrhal syndrome with predominant changes in mucous membranes of the upper respiratory tract.
Etiology:
• Parainfluenza, 5 types of human parainfluenza virus that belong to paramyxovirus family (large RNA viruses 150-200 nm, contain hemagglutinine and neuraminidase with stable antigen structure).
• Respiratory syncitial (RS) virus, belong to paramyxovirus family (large polymorph RNA viruses 120-200 nm) doesn’t have neuraminidase and without hemagglutination ability, grew only on the tissues cultures.
• Rhinoviruses, with over 100 serotypes, belong to picornavirus family (small RNA viruses 20-30 nm, instable in the environment).
• Adenoviruses – a stable DNA-viruses of medium size, 70-90 nm, have A, B, C
antigens, could agglutinate the blood.
• Rheoviruses – 3 serotypes RNA-viruses of medium size, 70-80 nm, stable in the
environment.
• Enteroviruses
• Coronaviruses

Epidemiology   
·        A source of infection are patients with URT viral infection, and virus-carriers (Adenovirus, Rhinovirus,  Rheovirus and RS-virus)
·        Mechanism of transmission
o       droplet with inhalation of small or large airborne drops during coughing, sneezing, speaking, by contact with contaminated hands, toys ets.
o       also fecal-oral (for AdenovirusRheovirus infection)
·        Receptivity – early age children, from 6 month and under-fives, contagiousness is high (40-80%)
·        Seasonality – autmn-winter or winter-spring flashes and sporadic diseases during a year

Pathogenesis       inoculation of viruses in upper respiratory tract epitheliocytes, conjunctiva, lymph nodes
-         Local reproduction of virus
-         Development of inflammatory process in upper respiratory tract, destructive changes
-         Start of immune reactions
 

delete of the virus                 immune factors              possible viremia
                                               suppression                                  
                                                                                     damage of organs
                                                 bacterial                           and systems
                                             complications

Clinical classification of an Acute Upper Respiratory Tract Viral Infections

Etiology
Clinical forms
Severity
Course

Adenoviruses

Pharyngoconjunctival fever, catarrh of the Upper Respiratory Tract, keratoconjunctivitis, tonzyllopharyngitis, diarrhea (intestinal syndrome), mesadenitis, hepatosplenomegaly
Mild

Moderate

Severe
1. Without complications


Paramyxoviruses

Croup syndrome, catarrh of the Upper Respiratory Tract, tonzyllopharyngitis,
2. With complications

RS-viruses

Acute bronchitis, bronchiolitis, Croup syndrome


Rhinoviruses

Rhinitis, rhinopharyngitis, catarrh of the Upper Respiratory Tract, interstitial pneumonia, Croup syndrome (seldom)



Clinical criteria

Common clinical symptoms:
·        Complaints: more or less severe symptoms of general intoxication, catarrhal symptoms are sore throat (considerably rarer is pharyngeal pain), cold, dry cough.
·        Moderate hyperemia, mainly palatal arch, soft palate, uvula, back pharyngeal wall with the presence of grittiness (lymphoidc follicles are enlarged).
·        Hyperemia of nasal mucosa.
·        Tonsils are mainly intact (except adenoviral infection).
·        Conjunctivitis (more or less severe, in dependence on the type of URTI).
·        Signs of a few parts of upper respiratory tract inflammation.
·        For every type of infection the prominent inflammation of one part of upper respiratory tract is characteristic with development of typical clinical signs.

 Parainfluenza:
·        Sporadic morbidity, grows in winter.
·        Latent period is 2-7 days.
·        Acute beginning.
·        Toxic syndrome is mild or moderate.
·        Catarrhal phenomena are not severe.
·        A basic clinical sign is a catarrh of upper respiratory tract.
·        Peculiarities in infants and under-fivesa croup syndrome is often the first display.

Adenovirus infection:
·        Sporadic morbidity and epidemic flashes.
·        Winter seasonality, possible flashes in summer.
·        Latent period is 2-12 days.
·        Acute beginning.
·        The first symptom is a catarrh of upper respiratory tract
·        Toxic syndrome is moderate.
·        Conjunctivitis (photo 89, 90).
·        Lymphoprolipherative syndrome (acute viral tonsillitis, neck lymph nodes enlargement, hepatomegaly (rare splenomegaly).
·        Intestinal syndrome.
·        Peculiarities in infants: often dyspeptic syndrome (vomiting, diarrhea), bronchitis, interstitial pneumonia,  rare – lymph nodes enlargement, conjunctivitis


Conjunctivitis

IMG_90
Conjunctivitis

RS-infection:
·        Latent period is 3-7 days.
·        Winter seasonality, acute beginning.
·        The children of senior age have mild forms (as an acute bronchitis).
·        Croup is less common.
·        Peculiarities in infants: often bronchiolitis, interstitial pneumonia

Rhinovirus infection:
·        Epidemic flashes (in winter, in autumn).
·        Latent period is 1-5 days.
·        Intoxication is absent or mild,
·        Acute rhinitis with large effusion (mucus) from the first days of illness
·        Often bacterial complications (later – purulent effusion from the nose).
·        Peculiarities in infants: rhinoviral infection with often development of tracheobronchitis

Common peculiarities in infants:
·       Poor feeding,
·       Decrease of body weight,
·       Less acute beginning,
·       Less intoxication,
·       Bacterial complications (otitis, pneumonia, etc.) and mortality appear more often.

Laboratory and instrumental investigations

·        Identification of virus from nasopharyngeal smears (also feces or blood in Adenovirus infection ) by culture, immunofluorescence, or ELISA.

·        Serologic diagnosis to find antibodies against viruses (CBR, DHAR) with fourfold increasing of antibodies title in 10-14 days may be used.

·        In CBC,  mainly leucopenia (normocytosis) with a shift to the left and relative lymphomonocytosis.
·        During X-ray  – strengthening of the pulmonary picture

Etiological diagnosis may be put in case of the virus identification, in other case diagnosis will be URT viral infection + leading clinical syndrome (for example: URT viral infection: rhinopharyngitis, or URT viral infection: obstructive bronchitis, Respiratory insufficiency 2nd degree; with intestinal syndrome.

Differential diagnosis should be performed between other viral respiratory tract infections, allergic rhinitis, foreign body aspiration, epiglottitis, bacterial tracheitis, pertussis, measles, Epstein-Bar Virus infection, bacterial croup.
·        Rhinoviral infectionwith allergic rhinitis, foreign body of the nose.
·        RS-infectionwhooping cough, chlamidiosis, mycoplasmosis.
·        Adenoviral infectionwith infectious mononucleosismicoplasmosis, and measles.
·        Parainfluenzawith true croup in diphtheria, other viral croup (i.e. in measles).

Differential Diagnosis between Viral Respiratory Infections

Signs and symptoms
Influenza
Parainfluenza
Adenoviral infection
RS-infection
Rhinoviral infection
Respiratory tract
Tracheitis
Laryngitis
Pharyngotonsillitis
Bronchitis, bronchiolitis, pneumonia
Rhinitis
Intoxication
Severe
Moderate
Moderate
Moderate
Mild
Catarrhal s-m
Mild
Moderate
Expressed
Expressed
Expressed
Temperature
High
Moderate
High, for long period
Moderate
Subfebril
Eye pain
Present
Absent
Absent
Rarely
Absent
Myalgias, Arthralgia
Expressed
Absent
Moderate
Rarely
Absent
Hemorrhages
May be present
Absent
Absent
Absent
Absent
Rhinitis
Moderate
Moderate
Expressed
Moderate
Expressed
Cough
Dry
dry, hoarseness, “barking”
Often repeated, with obstructive component
Rarely
Conjunctivitis
Absent
Absent
Often
Absent
Absent
Pharyngeal hyperemia
Expressed
Moderate
Expressed, tonsillitis
Moderate
Moderate
lymphadenopathy
Absent
Absent
Polyadenopathy
rarely: neck, submandibular
Absent
Liver
Normal
Normal
Often enlarged
May be enlarged
Normal
Spleen
Normal
Normal
May be enlarged
Normal
Normal
Diarrhea
Absent
Absent
May be present
Absent
Absent

Croup Syndrome
Stenotic laryngotracheitis, or false croup, exists in case of ARVI (influenza, parainfluenza, аdenoviral infection), measles, Chickenpox. Diphtheria of the respiratory ways has clinic of true croup, which necessary to differentiate with false croup.
Symptoms
Croup stages
1st     (compensated)
2nd(subcompensated)
3rd(decompensated)
4th (asphyxia)
acute beginning, more often at night with URTI previous signs (high temperature, catarrhal syndrome, pharyingitis: hyperemia of the pharynx and soft palate, catarrhal conjunctivitis, scleritis may be present);
Typical triad:
Barking cough;
Hoarseness;
Stridor.
Typical triad, but Stridor appears only when child is irritable, during physical exercises.
Laboratory signs of breath failure are absent (lips are pink, blood gases are normal), metabolic acidosis may be present.
Moderate breath failure (skin pallor, perioral cyanosis, tachycardia);
irritability;
Stridor with moderate involvement of all respiratory muscles;
Barking cough;
Hoarseness;
рО2 is decreased or on the lower normal grade;
рСО is normal;
Severe breath failure (stable cyanosis of lips, acrocyanosis, pallor); Expressed irritability, anxiety; Stridor with moderate involvement of all respiratory muscles with depression of lower part of sternum; tachycardia, deficit of pulse during inspiration; dullness of cardiac tones, myocardial dilatation may be present, cardio-pulmonary insufficiency; рО2is decreased (50-70 mm Hg.); рСО2 is increased (48-50 mm Hg.)
skin is pallor-gray, cyanotic, cold extremities;
breathing is superficial, gasping, or apneal;
progressive bradycardia;
subnormal temperature;
unconsciousness, seizures;
no controlled urination and defecation;
p О2 decreases to 50-40 mm Hg.;
р СО2 increases to 70-100 mmHg.;
Death.


Differential Diagnosis of the Respiratory Tract Diphtheria

Signs
Parainfluenza 
Diphtheria  
Chicken pox
Measles
Beginning

acute
gradual

acute
acute
Main signs
Catarrhal symptoms from the upper respiratory tract, laryngitis

Laryngitis, slowly development of airways obstruction, low intoxication
rashes
Catarrhal symptoms from the upper respiratory tract, conjunctivitis, rashes
Catarrhal symptoms (cough, corryza)
Expressed, moderate
absent
mild
expressed
Character of the cough
dry, rough, barking
“ barking”, then soundless
is rare
dry, or moist
Voice
Hoarse 
Hoarse, then soundless
Is not changed
May be hoarse
Oropharyngeal changes

Moderate hyperemia
Absent or may be combined with oropharyngeal diphtheria
absent
Exanthema, light hyperemia
Lymphadenitis

absent
regional
absent
May be plural
Pathomorphology
Edema of the larynx
Obstruction by fibrinous membranes
Edema of the larynx
Edema of the larynx


TREATMENT:
Basic:
1.     Bed rest up to the normalization of body temperature,
2.     adequate rehydration with oral fluids (lemon tearaspberry tea, warm alkalic drinks
3.     vitaminized milk-vegetable food;
4.     Control of fever and myalgia (when the temperature is more than 38.5-39˚C); in children before 2 mo and in case of perinatal CNS damage, seizures in the history, severe heart diseases – when the temperature is up to 38˚C with acetaminophen (paracetamol 10-15 mg/kg not often than every 4 hours (not more than 5 times per day) oribuprophen 10 mg/kg per dose, not often than every 6 hours. Aspirin is contraindicated for children before 12 years.
5.     Nasal drops (in infants before 6 mo – physiologic saline solutions as Salin; in elder children – naphtizin, rhinasolin, nasivin for children 1-2 drops 3 t.d. in the nostrils, not more than 3 days
6.     In case of dry cough – cough supressors (such as dextramethorphan, synecod)
7.     Mucolytics in case of the moist nonproductive cough (ambroxol, acetylcystein etc.)

Antiviral treatment may be used
·        Arbidol to the children elder than 12 yrs. — 0.2 g; children of 6-12 yrs. — for 0,1 g,  children of 2-6 yrs. — 0.05 g 4 t.d. for 3-5 days
·        Thiloron to the children elder than 7 yrs. through a mouth: 60 mg/day in 1, 2, 4, 6 day of treatment
·        Innosini pranobex 50 mg/kg daily for 5 days
·        Adenovirus conjunctivitis treatment – antiviral eye drops: poludanum, interferon, 0.05% deoxyribonuclease or 0.5% tebrophen ointment; corticosteroids as  Dexamethazonum for 4-5 days.

Antibiotics are appointed
1. In case of complications caused by bacteria, micoplasm or chlamydia, as:
• Middle otitis
• Sinusitis
• Acute tonsillitis
• Bronchitis
• Pneumonia
2. At suspicion of secondary bacterial infection, children that are risky for bacterial infection development, with body temperature > 38 °C more than 3 days, leucocytosis morethan  15x109/l. Antibiotics from the following groups are used:
• Aminopenicillines protected by clavulanic acid (amoxicillin clavulanate);
• Cefoperason in combination with sulbactam, cefuroxim, cefpodoxim
• Macrolydes (clarythromycin, azithromycin, spiramycin);
• Cephalosporines of 3rd-4th generation also are used.
• At presence of the methycillin resistant staphylococcus – vancomycin, in case of nosocomeal pneumonia carbapenems are appointed.

Management of croup depends on the severity of disease.
At the 1st degree of stenosis treatment of the child should be started at home:
·        Air in an apartment must be moistened. An emotional and physical comfort is provided for a child.
·        Local therapy is directed on the improvement of venous outflow and normalization of lymph outflow:  warming of interscapular area, shin muscles, heels.
·        A dry heat should be placed on a neck.
·        Warm dosed alkalic drink.
·        Inhalations by antioedematous mixture, steam inhalations.
·        From medicinal therapy:  vitamin C and P, and antihistaminic medicine in age-old doses.
·        Hospitalization only in the case of presence of problems in a transport connection between a hospital and child’s placement.

At the 2nd degree of stenosis a child must be transported into the hospital, where is possibly of artificial pulmonary ventilation.
Treatment of child must begin on the prehospital stage with continuation in the hospital.
·        Inhalation of water-wet and warmed oxygen.
·        Sedative medicine with the purpose of diminishing the inspiratory efforts.
·        Glucocorticoids 10 mg/kg per day by prednisolon. A dose is distributed on 4-6 receptions without the observance of biological rhythm.
·        Antihistaminic preparations in age-old doses (dimedrolum).
·        Careful treatment of bronchial obstructive syndrome: broncholytics, mucosolvents. At a considerable obstruction tracheobronchial tree lavage is done during a few hours.
·        A decrease of child’s body weight on 3-4% (stimulation of urination with reduction of daily liquid receipts to 80% of physiological amount).
·        Sanation of tracheobronchial tree and feeding the child before next introduction of Sedative medicines. 

At the 3rd degree of stenosis next is added:
·        Obligatory providing of artificial respiratory ways ventilation (intubation of trachea, tracheotomy if it’s impossible to put an intubation tube into the trachea)
·        Under the heart rate control it is possible to use adrenalin inhalations (1:20, 1:15) that enables the edema of subvocal space decrease quickly, but not for a long time.

At the 4th degree of stenosis a pneumo-cardial reanimation, treatment of cerebrum edema-swelling is performed.

Prophylaxis of URT viral infection
1.    Intranasal alpha2-interferon was active only against rhinoviruses and prevented a cold in only 40% of cases. It must be given not longer than 1-2 weeks.
2.    Arbidol to the children elder than 12 yrs. — 0,2 gs; children of 6-12 yrs. — for 0,1 gs,  children of 2-6 yrs. — 0,05 gs 1 t.d. for 10-15 daysor Thiloron to the children elder than 7 yrs. through a mouth: 60 mg once a week during 6 wks.
3.     Adaptogens, multivitamins
·        To avoid a contact with persons which have displays of URT infection;
·        To limit visits of places with large accumulation of people;
·        To ventilate an apartment often;
·        To teach children to wash hands often with soap during 20 seconds;
·        To teach children to cough and sneeze in a serviette;
·        To aim not to touch eyes, nose or mouth by unwashed hands;
·        To avoid cuddles, kisses and greeting by hands;
·        To cover a nose and mouth at a sneeze or cough by nasal serviette which at once it is needed to throw out after the use;
·        To teach children not to suit to the patients nearer than on one and a half - two meters;
·        Ill children must stay at a home (not to visit preschool establishments and schools);
·        The moist cleaning up of apartments is needed not less than two times a day.

Key words and phrases: viral upper respiratory tract infections, common cold, Croup,
mist tent, humidification, Ribavirine, parainfluenza, adenovirus, RS-virus, rhinovirus.

References
Main:
1.     Ambulatory pediatric care\ edited by Robert A. Derchewitz;-2- nd ed. Lippincot-Raven, 1992.- P.602-605, 611-615, 618-623, 753-755.
2.     Current therapy in pediatric infections disease-2\ edited by D.Nelson, M.D.-B.C.Decker Inc. TorontoPhiladelphia, 1988- P. 38-40, 44-45, 49-51.
3.     Principles and Practice of Pediatric Infectious Diseases. / Edited by Saran S. Long, Larry K. Pickering, Charles G. Prober, PhiladelphiaPa: Churchill Livingstone; 1997. – 1921 p.

Additional:
1.     Textbook of Pediatric Nursing.  Dorothy R. Marlow; R. N., Ed. D. –London, 1989.-661p.
2.     Pediatrics ( 2nd edition, editor – Paul H.Dworkin, M.D.) – 1992. – 550 pp.

1 comment:

  1. Great post.This article is really very interesting and effective.I think its must be helpful for us. Thanks for sharing your informative medical article

    ReplyDelete