DISORDERS OF THE RESPIRATORY SYSTEM

1. DISORDERS OF THE RESPIRATORY SYSTEM Department of Pediatrics Soochow University Affiliated Children’s Hospital

2. BACKGROUND • Respiratory tract infections(RTI) is the most common infectious diseases of childhood • RTI is from trivial to life-threatening illness • About 350,000 children under 5 years died of pneumonia every year in China • The commonest diseases in children living in developing country : the first is pneumonia, the second is diarrhea, the third is rickets(Vitamin D defficiency) , the forth is anemia • Pneumonia is very important disease in children

3. Anatomy and radiology

5. Throat anatomy

9. Title Page Diaphragm Rightlung

10. Title Page Left lung

11. Symptoms and signs

12. Symptoms and signs • Cough • Wheeze • Stridor

13. Cough

14. Causes of cough by age

15. Causes of Cough • AcuteChronic Upper respiratory tract infectionAsthma Bronchiolitis Postnasal drip Pneumonia;Gastro-oesophageal reflux aspiration Foreign body Cystic fibrosis

16. Characteristics of coughs

17. History –must ask • What does the cough sound like? • What is the sputum like? • When is the coughing worst? • Is the cough acute,persitent or recurrent? • Is the child ill? • Are the associated symptoms or precipitating factor? • Does anyone smoke in the family? • Past medical history.

18. Physical examination-must check! • Growth • Signs of respiratory distress. • Examination of the chest • Other signs

19. Investigations of their relevance in a coughing child

20. Clues to the differential diagnosis of the coughing child

21. Managing cough as a symptom • Antibiotics are too often prescribed for cough in the primary care setting. They have no place for URTIs, and should only be given if there is good evidence of infection of lower tract. • Cough is unusual in the treatment if often directed at he symptom rather than the cause. In general, little is to be gained by treating a cough per se unless it disrupts sleep or school. • There are two categories of medication: expectorants and cough suppressants. Expectorants are commonly prescribed but have never been shown to be effective. Codeine is the most effective cough suppressant. In children , codeine can strictly limit use. • Humidifying the air, lozenges

22. Stridor Stridor is a noise heard on inspiration and is cause by narrowing of the extrathoracic upper airway.

23. Causes of stridor • Acute causes croup acute epiglottitis foreign body • Chronic causes laryngomalacia subglottic stenosis

24. Approach to the child with stridor • Assess how severe the airway obstruction is and observe any progression. • Assess the likelihood of foreign body aspiration. • Look for the systemic features of acute epiglottitis, and hospitalize as an emergency. • Do not examine the throat if epiglottitis is suspected.

25. History • Coryza and fever the commonest cause of stridor is croup (acute laryngo-tracheal-bronchitis) when the stridor coincide with a barking cough. It is often preceded by coryza symptoms and fever. The main differential diagnosis is epiglottitis ( a life threatening illness ). In epiglottitis, the child is severely ill. • Nature of the tridor. The degree of stridor depends on the effort of inspiratory breath. • Aspiration. Aspiration of foreign body should always be considered in acute stridor. • Features of onset. Laryngomalacia (floppy larynx) is a congenital condition which resolves with age. Subglottic stenosis can develop after a previous intubation.

26. Physical examination • Chest signs. Signs in the chest including crepitations and wheeze are strongly suggestive of croup and are very uncommon with acute epiglottitis and upper airway foreign body obstruction. • Airway obstruction. Stridor is an important sign because it may proceed to acute airway obstruction. Never examine the throat of a child with a severe stridor, only be undertaken in the presence of an aneasthetist who can intubate the child if necessary.

27. Signs of increasing airway obstruction • Cyanosis • Confusion • Reduction in stridor with exhaustion • Drooling with increasing dysphagia

28. Investigations Appropriate investigations in children with stridor and the significance

29. Clues to the differential diagnosis of stridor

30. Managing stridor • Stridor caused by croup is usually a self-limiting condition. If the condition worsens, hospital admission is necessary for observation. • If acute epiglottitis is suspected, urgent transfer to hospital for assessment, antibiotic treatment and intubation is essential as airway obstruction is very likely to develop. • Complete upper airway obstruction caused by a foreign body is medical emergency.

31. Wheeze Wheeze is a breath sound that is usually produced by air passing through partially fluid-filled narrowed intrathoracic airways. It is a prolonged musical note heard mainly on expiration and is very common in childhood.

32. Common causes of acute wheeze • Asthma • Bronchiolitis and other viral agents • Air pollutants (e.g. sulphur- dioxide) • Aspiration of food or a foreign body • Cystic fibrosis • Sequelae of neonatal lung disease (bronchopulmonary dysplasia) • Cardiac failure

33. Approach to the wheezing child • Asthma is by definition recurrent wheezing. • Diagnosis asthma with caution below the age of 3year. • Tachypnea, alar flaring and intercostal/subcostal recessions are signs of respiratory distress. • Unilateral wheeze in a toddler is suggestive of a foreign body. • Children with asthma in general do not need a chest Xray at each attack. • Localized chest findings often do not correlate with those on the Xray.

34. History • The acute episode. Was there a triggering event? • Severity of the episode. Find out how incapacitated the child is. Ask if he or she is able to feed normally and if the wheezing interfered with play and activity. • Family history. • History of choking. • Apnea. Bronchiolitis and other viral infections cause wheezing infants and may be associated with apnea and quite severe respiratory distress.

35. Physical examination – must check • Assessment of growth. • Signs of respiratory distress. • Chest signs. • Other signs. Barrel chest, clubbing. • Peak flow. This should be apart of the assessment of any wheezing or breathless child who is old enough to cooperate.

36. Investigations • Most children with acute wheeze require only a careful history and examination. • An acute onset of wheeze in a very young child, asymmetrical signs on examination or failure to thrive demand investigation. • The child who shows severe sighs of respiratory distress will also need careful assessment for respiratory failure.

38. Managing wheezing • Children with acute onset of wheeze and their parents may be very frightened by the symptom and reassurance is necessary after appropriate assessment. • Asthma is the commonest cause of recurrent wheezing. • Some babies wheeze very persistently. If the wheeze is not affecting eating, temperament and growth, this need not arouse too much concern. Such children have been called “happy wheezers” and the symptoms subside as they grow.

39. Infections

40. Pathogens In URTIS • virus>90% (RSV,Influenzavirus,Parainfluenzavirus,Adenovirus) • bacteria (Streptococcus pneumonia,Heamophilus influenzae, Streptococci,Staphylococcus) • mycoplasma • …….

41. In LRTIS • virus about one in three • bacteria about one in three • virus + bacteria about one in three • mycoplasma? • …….

42. Upper respiratory tract infections The classic triad of symptoms includes : fever, rhinorrhoea, and a painful throat • Otitis media • Tonsillopharyngitis • Laryngotracheobronchitis (Croup)

43. Upper respiratory infection (Cold) • Definition    The common cold generally involves a runny nose, nasal congestion, and sneezing. You may also have a sore throat, cough, headache, or other symptoms. Over 200 viruses can cause a cold.

45. Treatment of URI • Antibiotics should NOT be used to treat a common cold. They will NOT help and may make the situation worse! Thick yellow or green nasal discharge is not a reason for antibiotics, unless it lasts for 10 to 14 days without improving. (In this case, it may be sinusitis.) • New anti-viral drugs could make runny noses completely clear up a day sooner than usual (and begin to ease the symptoms within a day). It’s unclear whether the benefits of these drugs outweigh the risks. • Chicken soup has been used for treating common colds at least since the 12th century. It may really help. The heat, fluid, and salt may help you fight the infection.

46. Croup • Definition    Croup is breathing difficulty accompanied by a "barking" cough. Croup, which is swelling around the voacl cords, is common in infants and children and can have a variety of causes

49. Causes, incidence, and risk factors • Viral croup is the most common. Other possible causes include bacteria, allergies, and inhaled irritants. Acid reflux from the stomach can trigger croup. • Croup is usually (75 percent of the time) caused by parainfluenza viruses, but RSV, measles, adenovirus, andinfluenzacan all cause croup. • Before the era of immunizations and antibiotics, croup was a dreaded and deadly disease, usually caused by the diphtheria bacteria. Today, most cases of croup are mild. Nevertheless, it can still be dangerous. • Croup tends to appear in children between 3 months and 5 years old, but it can happen at any age. Some children are prone to croup and may get it several times.

50. Symptoms of croup • Croup features a cough that sounds like a seal barking. Most children have what appears to be a mild cold for several days before the barking cough becomes evident. As the cough gets more frequent, the child may have labored breathing or stridor (a harsh, crowing noise made during inspiration). • Croup is typically much worse at night. It often lasts 5 or 6 nights, but the first night or two are usually the most severe. Rarely, croup can last for weeks. Croup that lasts longer than a week or recurs frequently should be discussed with your doctor to determine the cause.