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

Transcription

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

2 BACKGROUND 1. Respiratory tract infections(rti) is the most common infectious diseases of childhood 2. RTI is from trivial to life-threatening illness 3. About 350,000 children under 5 years died of pneumonia every year in China 4. 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 5. Pneumonia is very important disease in children

3 Anatomy and radiology

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5 Throat anatomy

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9 Diaphragm Title Page Right lung

10 Title Page Left lung

11 Symptoms and signs

12 Symptoms and signs Cough Wheeze Stridor

13 Cough

14 Causes of cough by age Infancy Preschool School -age to adolescence infections infections asthma upper respiratory tract upper respiratory tract infections bronchiolitis croup upper respiratory tract pneumonia acute bronchitis Cigarette smoking Congenital malformation of airway pneumonia Postnasal drip (UACS) Gastro-oesophageal reflux Foreign body psychogenic Cytic fibrosis asthma Cytic fibrosis Passive smoking

15 Causes of Cough Acute Chronic Upper respiratory tract infection Asthma Bronchiolitis Postnasal drip Pneumonia; Gastro-oesophageal reflux aspiration Foreign body Cystic fibrosis

16 Characteristics of coughs Loose, productive wheezy Barking Paroxysmal(with or without vomiting ) Nocturnal Bronchitis, wheezy bronchitis, cystic fibrosis, bronchiectasis Asthma,wheezy bronchitis, croup croup Cystic fibrosis, pertussis, foreign body, asthma Asthma, sinusitis Most severe on waking Cystic fibrosis, bronchiectasis With vigorous exercise Disappears with sleep Exercise induced asthma, cystic fibrosis, bronchiectasis Habit cough

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 Investigation What you are looking for Full blood count Blood culture Pernasal swab Chest Xray Chest Xray and barium swallow Sweat test Videofluoroscopy and bronchoscopy Trial of bronchodilators, PEF Raised white count and shift to the left with bacterial infection. Possible eosinophilia in asthma Lower respiratory tract infection To identify pertussis Lower respiratory tract infection Congenital anomalies of the airway, gastrointestinal reflux Cystic fibrosis Aspirated foreign body, malformation of airway Asthma

20 Clues to the differential diagnosis of the coughing child Fever Feature of cough Respiratory signs URTI +/- Non-productive None, other than transmitted sound pneumonia + productive Alar flaring, intercostal, subcostal retractions, +/-? Dullness to percussion, diminished breath sounds Athma Foreign body - or +/- if URTI present -(until infection develops) Wheezy, often nocturnal or on exercise. Often preceded by choking episode Alar flaring, intercostal, subcostal retractions, expiratory wheeze(but may be absent at time to examination. Wheeze, diminished breath sounds on right

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 Investigations What you are looking for Full blood count Blood culture Neutrophilia with excess granulocytes suggests bacterial infection To identify haehophilus influenzae Blood gas Low PaO 2,high PaCO 2, or respiratory acidosis indicates respiratory failure

29 Clues to the differential diagnosis of stridor Age Clinical features Croup 6-24 months Coryza prodrome Barking cough Epiglottitis 2-7 years Toxicity and high fever Drooling Foreign body 9-18 months History and sudden onset laryngomalacia newborn Presents at birth and persitst Worse on crying Improves with age Subglottic stenosis 0-6 months Previous history of intubation Exacerbatins with upper respiratorytract infection

30 Managing stridor Stridor caused by croup is usually a selflimiting 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 fluidfilled 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.

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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.

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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

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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.

51 Signs and tests Children with croup are usually diagnosed based on the parent's description of the symptoms and a physical exam. Sometimes a doctor will even identify croup by listening to a child cough over the phone. Occasionally other studies, such as x- rays, are needed. A physical examination may show chest retractions with breathing. Listening to the chest through a stethoscope may reveal prolonged inspiration or expiration, wheezing, and decreased breath sounds. An examination of throat may reveal a red epiglottis. A neck x-ray may reveal a foreign object or narrowing of the trachea

52 Epiglotitis EPIGLOTITIS IS A MEDICAL EMERGENCY Definition Epiglottitis is a disorder caused by inflammation of the cartilage that covers the trachea (windpipe). Do not make any attempts to look into the patient's mouth if epiglottitis is suspected.immediate emergency medical help is imperative!

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54 Epiglottitis is most common in children between 2 and 6 years old and is usually caused by the bacterium Haemophilus influenzae, although it may be caused by other bacteria or viruses. Although rare, epiglotitis can occur in normal adults. Because it is rare in adults, it may be easily overlooked as a diagnosis. The condition can progress rapidly. In the US, the incidence of this disease has decreased steadily since Haemophilus influenzae type B (Hib) vaccine became a routine childhood immunization in the late 1980s.

55 Haemophilus influenzae

56 Symptoms of epiglottitis Drooling Sore throat Difficulty swallowing Difficulty breathing (patient may need to sit upright leaning slightly forward to breathe adequately) Stridor (noisy breathing, "crowing" sound when inhaling) Hoarseness Chills, shaking Fever Cyanosis (blue skin coloring)

57 Signs and tests Stridor may be present. Blood culture or throat culture may show H. influenzae or other bacteria. A CBC may show an elevated WBC count. Neck x-rays may show enlargement of the epiglottis

58 Treatment of epiglottitis Hospitalization is required because this is an emergency situation. The patient is usually admitted to the intensive care unit. Treatment usually involves the administration of humidified oxygen, which is oxygen that has been moistened to help the patient breathe. The patient will probably be intubated, meaning a tube is passed through the nose or mouth into the trachea to help the patient breathe. Intravenous fluids are given to increase hydration. Antibiotics are used to treat the infection. Corticosteroids may be used to decrease the swelling of the throat.

59 Lower respiratory infections Bronchiolitis Pertussis Pneumonia tuberculosis

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61 Definition of Pneumonia Pneumonia is an inflammation of the lungs caused by an infection. Many different organisms can cause it, including bacteria, viruses, and fungi. Pneumonia can range from mild to severe, even fatal. The severity depends on the type of organism causing pneumonia as well as your age and underlying health.

62 Pathogens(etiology) Bacterial pneumonias tend to be the most serious and, in adults, the most common cause, especially Streptococcus pneumoniae (pneumococcus). Respiratory viruses are the most common causes of pneumonia in young children, peaking between the ages of 2 and 3. By school age, the bacterium Mycoplasma pneumoniae becomes more common.

63 Pathogens(etiology) Figure 16.2

64 Classification Pathology Pathogen Duration of illness Patient s condition(common,severe) Type of illness(typical,atypical,sars ) Region(CAP,HAP)

65 Clinical manifestations symptoms Cough with greenish or yellow mucus; bloody sputum happens on occasion Fever with shaking chills Sharp or stabbing chest pain worsened by deep breathing or coughing Rapid, shallow breathing Shortness of breath

66 Signs Crackles Decreased breath sounds Bronchial breathing Consolidation Lymphadenectasis

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68 Lobar pneumonia consolidation

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70 Diagnosis History Clinical features X-ray: a chest x-ray is required to confirm the diagnosis Lab. examination: Blood count Blood culture Viral isolation(nasophrayngeal aspiration)(apaap/dfa)

71 NOTICE It is difficult to distinguish between viral and bacterial and mycoplasma infections. Young children and babies are not good providers of sputum. The following all suggest bacterial pneumonia Polymorph, leucocytosis Lobar consolidation Pleural effusion

72 Differential diagnosis Bronchitis / bronchiolitis Foreign object TB Infant wheezing Childhood asthma Cystic fibrosis Whooping cough(pertussis)

73 Management/Treatment Usual treatment o 2 /nurse/nutrition Antibiotics Bacterial infection Fellowed bacterial infection Antibiotics choice: according to the bacterial sensitive to drugs,but it is difficult because positive rate of blood culture is very lower In moderate to severe pneumonia: cefuroxime provider satisfactory cover If mycoplasma is suspected, erythromycin should be given

74 bronchiolitis Bronchiolitis is an inflammation of the bronchioles (small passages in the lungs) usually caused by a viral infection The disease usually affects children under the age of 2, with a peak age of 3 to 6 month, and is a common, sometimes severe illness. Respiratory syncytial virus (RSV) is one common cause. Other viruses that can cause bronchiolitis include: parainfluenza, influenza, and adenovirus.

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77 Risk factors include for bronchiolitis Age (less than 6 months old) No history of being breastfed Prematurity (born before 37 weeks gestation) Exposure to cigarette smoke Crowded living conditions

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79 Symptoms of bronchiolitis Cough, wheezing, shortness of breath, or difficulty breathing Rapid breathing (tachypnea) Intercostal retractions Nasal flaring in infants Fever (variable) Bluish skin due to lack of oxygen (cyanosis

80 Signs of bronchiolitis Wheezing and crackling sounds are heard by stethoscope examination of chest. Decreased blood oxygen levels are detected. Tests often include a chest x-ray and blood gases. Samples of nasal fluid may be cultured to determine what virus is present.

81 Tuberculosis Pulmonary tuberculosis (TB) is a contagious bacterial infection caused by Mycobacterium tuberculosis. The lungs are primarily involved, but the infection can spread to other organs

82 Tuberculosis of the lungs

83 Causes, incidence Tuberculosis can develop after inhaling droplets sprayed into the air from a cough or sneeze by someone infected with Mycobacterium tuberculosis. The disease is characterized by the development of granulomas(granular tumors) in the infected tissues. The usual site of the disease is the lungs, but other organs may be involved. The primary stage of the infection is usually asymptomatic (without symptoms). In the United States, the majority of people will recover from primary TB infection without further evidence of the disease.

84 Factors that may contribute to the increase in tuberculous infection Increase in HIV infection Increase in number of homeless individuals (poor environment and poor nutrition) The appearance of drug-resistant strains of TB

85 TB symptoms Limited to minor cough and mild fever, if apparent Fatigue Unintentional weight loss Coughing up blood Fever and night sweats Phlegm-producing cough

86 Additional symptoms that may be associated with this disease Wheezing Excessive sweating, especially at night Chest pain Breathing difficulty

87 Signs and tests Examination of the lungs by stethoscope can reveal crackles (unusual breath sounds). Enlarged or tender lymph nodes may be present in the neck or other areas. Fluid may be detectable around a lung. Clubbing of the fingers or toes may be present. Chest x-ray Sputum cultures Tuberculin skin test Bronchoscopy Thoracentesis Chest CT Rarely, biopsy of the affected tissue (typically lungs, pleura, or lymph nodes)

88 Treatment of TB The goal of treatment is to cure the infection with antitubercular drugs. Daily oral doses of multiple drugs -- which may include combinations of rifampin, isoniazid, pyrazinamide, ethambutol, or occasionally others -- are continued until culture results show the drug sensitivity of the mycobacterial infection. This helps to guide the selection of drug therapy. Treatment is typically continued for 6 months, but longer courses may be required for AIDS patients or those whose disease responds slowly. For atypical tuberculosis infections, or drug-resistant strains, other drugs and different lengths of therapy may be indicated to treat the infection.

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90 Miliary tuberculosis

91 Tuberculosis, advanced - chest X-rays

92 Pulmonary nodule - front view chest X-ray

93 Pneumocystis carinii pneumonia This is an infection of the lungs caused by the fungus Pneumocystis carinii. Causes, incidence, and risk factors PCP is a pneumonia caused by the fungal organism Pneumocystis carinii, which is widespread in the environment, and is not a pathogen (does not cause illness) in healthy individuals. However, in individuals with weakened immune systems due to cancer, HIV/AIDS, solid organ and/or bone marrow transplantation, as well as individuals receiving chronic corticosteroids or other medications that affect the immune system, Pneumocystis carinii may lead to a lung infection.

94 Pneumocystis carinii pneumonia

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96 PCP

97 homework Common features of bronchiolitis are: A. Stridor B. Apnoea C. Hepatomegaly D. Paroxysmal coughing E. Wheeze (answer in text P68)

98 The following clinical findings are seen in lobar consolidation: A. Ipsilateral bronchial breathing B. Absent tactile vocal fremitus(tvf) C. Deviation of the trachea away from the affected side D. Hyperresonant percussion note E. Absent breath sounds (answer in text P68)

99 Thank you Scenes of Children s Hospital of Soochow Universi