Respiratory Disorders PDF

17 Respiratory disorders Upper respiratory tract infections 300...

17 Respiratory disorders Upper respiratory tract infections 300 Cystic fibrosis (CF) 317 Upper airways obstruction 302 Primary ciliary dyskinesia (PCD) 320 Lower respiratory tract infections 304 Immunodeficiency 320 Asthma 307 Sleep-disordered breathing 321 Cough 314 Respiratory care in children with Bronchiectasis 316 complex needs 321 Features of respiratory disorders in children: Presentation of respiratory disorders in children can be with either the clinical features of: Respiratory disorders are common: In the UK, they account for half of acute consultations with general Upper respiratory tract – coryza, sore throat, earache, practitioners in young children. sinusitis, cough or stridor. Respiratory disorders are the commonest reason for Lower respiratory tract: acute paediatric hospital admissions. Cough – The character and nature of the cough Asthma is the commonest chronic childhood illness in may suggest a particular diagnosis. In general, the UK. wet or moist cough suggests that there are extra Modern management of cystic fibrosis has markedly secretions. extended life expectancy. Increased rate of breathing – Whilst the normal ranges for respiratory rate are wide, particularly Predisposition to individual respiratory disorders varies for younger children, tachypnoea is one of the with age; for example, the type of acute respiratory infec- most sensitive signs of illness. However, this is not tions children experience at different ages is shown in specific for respiratory problems and also occurs in Figure 17.1. Infants and young children are particularly heart failure, metabolic disorders and sepsis. susceptible to viral infections following loss of protective maternal antibodies. Age also affects severity of illness; in general, neonates and infants are the most severely affected. The growing lungs of children are also particularly vulnerable to the long-term effects of environmental pollu- Relative tion and toxins, including cigarette smoke, which increases incidence the lifetime risk of several diseases including asthma and Pneumonia chronic obstructive pulmonary disease in adult life. Risk factors for respiratory disease in children or young people include: Bronchiolitis parental – genetic predisposition, maternal smoking Viral croup during pregnancy in the child or young person – prematurity or low Upper respiratory birthweight, especially with bronchopulmonary tract infections dysplasia, congenital heart disease, disorders causing muscle weakness, reduced immune function, lack or 0 1 3 5 10 18 incomplete immunization or cigarette use or vaping Age (years) environmental – household or air pollution, number of siblings, allergens, low socio-economic status, Figure 17.1 Age distribution of acute respiratory cigarette smoke and vaping. infections in children. F 2 A( DB 1B A 2 2C , C 2 / F )2 A 2/ , B E A (D DBC A AB 2 DB 0 C9 A DB B F C9 DC A BB A 9C , B E A. ( A 9CB A B AE  Summary The clinical features of respiratory tract disorders in infants and young children are: Cough. Respiratory noises – wheeze, stridor, crackles. 17 Increased rate of breathing. Increased work of breathing – dynamic chest recession. Reduced oxygen saturation which improves with Respiratory disorders supplemental oxygen and respiratory support if necessary. Figure 17.2 Marked sternal recession in an infant, indicating increased work of breathing. Upper respiratory tract infections Increased work (effort) of breathing – An increase in resistance in the airways or lungs will result Children have an average of five upper respiratory tract in an increase in the effort required to achieve infections (URTIs) per year in the first few years of life, adequate gas exchange. A conscious child will try but some infants and primary school-age children have as to keep blood carbon dioxide and oxygen levels many as 10–12 per year. Approximately 80% of all respira- normal. If the resistance is increased in the upper tory infections are URTIs; the term embraces a number of airway, then effort is increased in inspiration. If the different conditions: resistance is increased in the lower airway, then effort is increased in expiration. This is a specific common cold (coryza) indicator of respiratory illness. sore throat (pharyngitis, including tonsillitis) Chest recession – In infants and young children, chest acute otitis media recession is an important indicator of increased work sinusitis (relatively uncommon). of breathing, as they have compliant chest walls (Fig. 17.2). It is dynamic, occurring with each breath The child may have a combination of these conditions. due to an acute change in the effort required to Cough may be troublesome and may be secondary to overcome airway resistance. The recession can be attempts to clear upper airway secretions or a postnasal above the ribs (suprasternal), involve the chest wall drip. URTIs may cause: (sternal) or below the ribs (subcostal). As chest wall muscles are relatively weak, and the diaphragm difficulty in feeding in infants as their noses are is relatively strong, when the work of breathing blocked and this obstructs breathing increases the breathing pattern becomes abdominal. febrile seizures. This leads to ‘see-sawing’ of the chest and abdomen, with the chest moving in whilst the abdomen Hospital admission may be required if feeding and fluid moves out during inspiration. This contrasts with intake is inadequate. later childhood or adult life, when even if there is increased work of breathing, the stiffer chest wall and diaphragm move together, with both moving The common cold (coryza) outwards during inspiration. Whilst recession can still be seen, it tends to be between the ribs (intercostal). This is the most common infection of childhood. Classical Extra respiratory noises – Flow of air against a features include a clear or mucopurulent nasal discharge and resistance will lead to the generation of sounds. nasal blockage. The most common pathogens are viruses – A stethoscope makes lower airway sounds easier rhinoviruses (of which there are >100 different serotypes), to hear. Musical noises, e.g. wheeze, suggest coronaviruses, and respiratory syncytial virus (RSV). partial obstruction. Coarser sounds, e.g. crackles, Advice for parents that colds are self-limiting and there suggest increased secretions. is no specific curative treatment may reduce anxiety and Reduced oxygen saturation – In air, this is a sensitive save unnecessary visits to doctors. Pain is best treated with marker of respiratory illness. Oxygen saturation can paracetamol or ibuprofen. Antibiotics are of no benefit as also be low in children with cardiac conditions, but the common cold is viral in origin and secondary bacterial is less likely to increase to the normal range with infection is very uncommon. Cough may persist for up to supplemental oxygen. Specially designed probes are 4 weeks after a common cold. required according to the child’s size. Impending respiratory failure is suggested by: Sore throat (pharyngitis and tonsillitis) cyanosis persistent grunting Pharyngitis is usually caused by a viral infection (adeno- reduced oxygen saturation despite oxygen therapy virus, enterovirus or rhinovirus) and results in inflamma- rising pCO2 on blood gas tion of the pharynx and soft palate with variably enlarged exhaustion, confusion, reduced conscious level. and tender local lymph nodes. Tonsillitis is a form of pharyngitis causing intense inflammation of the tonsils, 300 Additional respiratory support will be required (see Ch. 6, often with a purulent exudate and may be caused by Paediatric emergencies). group A beta-haemolytic streptococci and Epstein–Barr F 2 A( DB 1B A 2 2C , C 2 / F )2 A 2/ , B E A (D DBC A AB 2 DB 0 C9 A DB B F C9 DC A BB A 9C , B E A. ( A 9CB A B AE  17 Respiratory disorders (a) (b) (c) (d) Figure 17.3 Appearance of the eardrum. (a) Normal; (b) acute otitis media; (c) otitis media with effusion; and (d) grommet. (Courtesy of Mr N Shah, Mr N Tolley, Mr Williamson, and Mr R Thevasagayam.) virus (infectious mononucleosis or glandular fever). Summary The tonsillitis of group A beta-haemolytic streptococci may produce a toxin responsible for the rash of scarlet fever (see Fig. 15.9a, Ch. 15, Infection and immunity). Acute otitis media Marked constitutional disturbance, such as headache, This is diagnosed by examining the tympanic apathy and abdominal pain is more common with bacte- membrane, which should be visualized in all rial infection, but it is not possible to distinguish clinically febrile children. between viral and bacterial causes, and less than a third Antibiotics marginally shorten the duration of pain of cases of tonsillitis are caused by bacteria. but do not reduce hearing loss. Antibiotics such as penicillin V or erythromycin hasten If recurrent, may result in otitis media with recovery from streptococcal tonsillitis on average by effusion, which may cause speech and learning only 16 hours. However, antibiotics may be indicated impairment from hearing loss. to eradicate beta haemolytic streptococci to prevent rheumatic fever in high incidence countries or in chil- dren at increased risk of severe infection. This requires 10 days of oral antibiotics. Rarely, children may require Every child with a fever should have their tympanic hospital admission for intravenous fluid administration membranes examined (Fig. 17.3a–d). In acute otitis media, and analgesia if they are unable to swallow solids or the tympanic membrane is bright red and bulging with liquids. Amoxicillin is best avoided as it may cause a loss of the normal light reflection (Fig. 17.3b). Occasionally, widespread maculopapular rash if the tonsillitis is due there is acute perforation of the eardrum with pus visible to infectious mononucleosis. in the external canal. Pathogens include RSV, rhinovirus, Children with recurrent tonsillitis or its complications pneumococcus, Haemophilus influenzae and Moraxella (e.g. peritonsillar abscess – quinsy) and those with sleep catarrhalis. Complications include mastoiditis (see Fig. 2.14a) disordered breathing (e.g. obstructive sleep apnoea) and meningitis, but these are rare. Pain should be treated may benefit from tonsillectomy and/or adenoidectomy. with regular analgesia and may be required for up to However, as acute sore throat is very common in children, a week. Otitis media usually resolves spontaneously. in order to prevent unnecessary surgery strict indications Antibiotics marginally shorten the duration of pain but for the operation have been adopted in some countries. have not been shown to reduce the risk of hearing loss. In the UK, surgery is usually deferred until a child has had Neither decongestants nor antihistamines are beneficial. either seven or more episodes of significant sore throat Recurrent ear infections can lead to otitis media with in the preceding 12 months, or five or more episodes in effusion (also called glue ear; Fig. 17.3c). Children are each of the two previous years, or three or more episodes usually asymptomatic apart from possible decreased in each of the previous three years. hearing. The eardrum is dull and retracted, often with a Tonsils and adenoids increase in size until about 8 years visible fluid level. Otitis media with effusion is very common of age and then gradually regress. In young children, the between the ages of 2 and 7 years. It usually resolves spon- adenoids grow proportionately faster than their airway. taneously, but may cause conductive hearing loss and Narrowing the airway is therefore greatest between 2 and interfere with normal speech development. There is no 8 years. For children where sleep disordered breathing is evidence of long-term benefit from the use of antibiotics, suspected, parents should be encouraged to obtain video steroids, or decongestants. Nasal inflation, where the child recordings of the child during sleep, as these can help make breaths out through a nostril to inflate a small balloon, decisions about the need for sleep recordings or surgery. may help by opening the eustachian tube, but the child usually needs to be school-aged to perform it. If hearing does not improve, surgery may be considered, with inser- Acute otitis media tion of tympanostomy tubes (grommets; Fig. 17.3d) with or without the removal of adenoids, but benefits often do Infants and young children are prone to acute otitis not last more than 12 months. media because their Eustachian tubes are short, horizon- tal, and function poorly. Most children will have at least one episode of acute otitis media and up to 20% will Sinusitis have three or more episodes. It is most common at 6–12 months of age. It causes earache and fever. Infection of the paranasal sinuses may occur with viral 301 URTIs. Occasionally, there is secondary bacterial infection, F 2 A( DB 1B A 2 2C , C 2 / F )2 A 2/ , B E A (D DBC A AB 2 DB 0 C9 A DB B F C9 DC A BB A 9C , B E A. ( A 9CB A B AE  with pain, swelling and tenderness over the cheek from Croup infection of the maxillary sinus. As the frontal sinuses do not develop until late childhood, frontal sinusitis is uncom- Viral croup accounts for over 95% of laryngotracheal mon in the first decade of life. Antibiotics and analgesia infections in children. Parainfluenza viruses are the most are used for acute sinusitis. common cause, but it may be triggered by rhinovirus, RSV and influenza. It typically occurs from 6 months to 6 years of age but the peak incidence is in the second year of life. 17 Upper airways obstruction It is most common in the autumn. The typical features are coryza and fever followed by: Severe upper airways obstruction results in choking, to hoarseness due to inflammation of the vocal cords Respiratory disorders clear the airway (see Ch. 6). Complete obstruction of a barking cough, like a sea lion, due to tracheal the upper airway rapidly leads to respiratory failure and oedema and collapse death. It may occur acutely as a result of an inhaled foreign harsh stridor body, or inhalation burns. variable degree of difficulty breathing with chest Partial obstruction of the upper airway leads to recession increased work of breathing accompanied by additional the symptoms often starting, and being worse, at night. noises on breathing. Variable upper airway obstruction leads to stertor (snoring when asleep), and fixed partial When the upper airway obstruction is mild, the stridor and airway obstruction leads to stridor, a high-pitched, musical, chest recession disappear when the child is at rest and the whistling sound. A brief explanation of why upper airway obstruction leads to stridor rather than wheeze is given in Figure 17.4. The causes of stridor are listed in Box 17.1. By Box 17.1 Causes of acute stridor (upper airway far the most common cause is viral laryngotracheobron- obstruction) chitis (‘croup’). The severity of upper airways obstruction is best Common causes assessed clinically by the characteristics of the stridor Viral laryngotracheobronchitis (‘croup’) (none, only on crying, at rest, or biphasic) and the degree Foreign body of accompanying chest retraction (none, only on crying, at rest). Severe obstruction also leads to increasing respira- Rare causes tory rate, heart rate, and agitation. Central cyanosis, drool- Laryngeal oedema (anaphylaxis and recurrent croup) ing of saliva from inability to swallow it or reduced level Inhalation of smoke and hot fumes in fires of consciousness suggest impending complete airway Trauma to the throat obstruction and the need for intubation. Pulse oximetry Retropharyngeal abscess can reliably detect hypoxaemia but, in contrast to paren- Bacterial tracheitis or epiglottitis chymal lung disease, it is a late feature in upper airways Severe lymph node swelling (malignancy, tuberculosis, obstruction. infectious mononucleosis, measles) Total obstruction of the upper airway may be precipi- tated by examination of the throat using a spatula. Avoid Hypocalcaemia looking at the throat of a child with upper airways obstruc- Vocal cord dysfunction tion unless full resuscitation equipment and personnel are Diphtheria (exceedingly rare) at hand. Inspiration Expiration 0 0 0 0 8 3 2 8 6 6 4 8 3 6 4 3 8 6 8 6 6 8 6 8 (a) (b) Figure 17.4 In normal breathing, during inspiration the negative intrapleural pressure dilates the intrathoracic airways but collapses the extrathoracic airway (a); and on expiration positive intrapleural pressure does the opposite (b). This explains why extrathoracic obstruction causes difficulty in inspiration, whereas intrathoracic obstruction causes 302 problems on expiration. Numbers represent pressures at different points. F 2 A( DB 1B A 2 2C , C 2 / F )2 A 2/ , B E A (D DBC A AB 2 DB 0 C9 A DB B F C9 DC A BB A 9C , B E A. ( A 9CB A B AE child can usually be managed at home. Parents should be Bacterial tracheitis and acute epiglottitis advised to observe the child closely for signs of increasing severity. The decision to manage the child at home or in Bacterial tracheitis and acute epiglottitis have similar clini- hospital is influenced not only by the severity of the illness cal features. The latter is now very rare since children in but also by the time of day, ease of access to hospital, the most countries are immunized against H. influenzae type child’s age (with a lower threshold for admission for those b (Hib). Presentation is with a very ill-looking child with