Pathogens

Viruses cause 80–90% of childhood respiratory infections. The most important are the respiratory syncytial virus (RSV), rhinoviruses, parainfluenza, influenza, metapneumovirus and adenoviruses. An individual virus can cause several different patterns of illness, e.g. RSV can cause bronchiolitis, croup, pneumonia or a common cold.

The important bacterial pathogens of the respiratory tract are Streptococcus pneumoniae (pneumococcus) and other streptococci, Haemophilus influenzae, Moraxella catarrhalis, Bordetella pertussis, which causes whooping cough, and Mycoplasma pneumoniae. Dual infections, with two viruses or with a viral and bacterial pathogen, may occur. Mycobacterium tuberculosis remains an important pathogen globally. Some pathogens cause predictable epidemics, such as RSV bronchiolitis every winter.

Host and environmental factors

An increased risk of respiratory infection is associated with a range of factors relating to the environment and host:

The child’s age influences the prevalence and severity of infections (Fig. 16.1). It is in infancy that serious respiratory illness requiring hospital admission is most common and the risk of death is greatest. There is an increased frequency of infections when the child or older siblings start nursery or school. Repeated upper respiratory tract infection is common and rarely indicates underlying disease.

Classification of respiratory infections

Respiratory infections are classified according to the level of the respiratory tract most involved:

The common cold (coryza)

This is the commonest infection of childhood. Classical features include a clear or mucopurulent nasal discharge and nasal blockage. The commonest pathogens are viruses – rhinoviruses (of which there are over 100 different serotypes), coronaviruses and RSV. Health education to advise parents that colds are self-limiting and have no specific curative treatment may reduce anxiety and save unnecessary visits to doctors. Fever and pain are best treated with paracetamol or ibuprofen. Antibiotics are of no benefit as the common cold is viral in origin and secondary bacterial infection is very uncommon.

Sore throat (pharyngitis)

The pharynx and soft palate are inflamed and local lymph nodes are enlarged and tender. Sore throats are usually due to viral infection with respiratory viruses (mostly adenoviruses, enteroviruses and rhinoviruses). In the older child, group A β-haemolytic streptococcus is a common pathogen.

Tonsillitis

Tonsillitis is a form of pharyngitis where there is intense inflammation of the tonsils, often with a purulent exudate. Common pathogens are group A β-haemolytic streptococci and the Epstein–Barr virus (infectious mononucleosis). Group A β-haemolytic streptococcus can be cultured from many tonsils; however, it is uncertain why it causes recurrent tonsillitis in some children but not in others.

Although the surface exudates seen in infectious mononucleosis are reported to be more membranous in appearance compared to bacterial tonsillitis, in reality it is not possible to distinguish clinically between viral and bacterial causes. Marked constitutional disturbance, such as headache, apathy and abdominal pain, white tonsillar exudate and cervical lymphadenopathy, is more common with bacterial infection.

Antibiotics (often penicillin, or erythromycin if there is penicillin allergy) are often prescribed for severe pharyngitis and tonsillitis even though only a third are caused by bacteria. They may hasten recovery from streptococcal infection. In order to eradicate the organism to prevent rheumatic fever, 10 days of treatment is required, but this is not indicated in the UK where rheumatic fever is now exceedingly rare. In severe cases, children may require hospital admission for intravenous fluid administration and analgesia if they are unable to swallow solids or liquids. Amoxicillin is best avoided as it may cause a widespread maculopapular rash if the tonsillitis is due to infectious mononucleosis.

Acute infection of the middle ear (acute otitis media)

Most children will have at least one episode of acute otitis media (OM). This is most common at 6–12 months of age. Up to 20% will have three or more episodes. Infants and young children are prone to acute otitis media because their Eustachian tubes are short, horizontal and function poorly. There is pain in the ear and fever. Every child with a fever must have their tympanic membranes examined (Fig. 16.2a–d). In acute otitis media, the tympanic membrane is seen to be bright red and bulging with loss of the normal light reflection (Fig. 16.2b). Occasionally, there is acute perforation of the eardrum with pus visible in the external canal. Pathogens include viruses, especially RSV and rhinovirus, and bacteria including pneumococcus, non-typeable H. influenzae and Moraxella catarrhalis. Serious complications are mastoiditis and meningitis, but are now uncommon. Pain should be treated with an analgesic such as paracetamol or ibuprofen. Regular analgesia is more effective than intermittent (as required) and may be needed for up to a week until the acute inflammation has resolved. Most cases of acute otitis media resolve spontaneously. Antibiotics marginally shorten the duration of pain but have not been shown to reduce the risk of hearing loss (see Ch. 5). It is often useful to give the parents a prescription, but ask them to use it only if the child remains unwell after 2–3 days. Amoxicillin is widely used. Neither decongestants nor antihistamines are beneficial.

Recurrent ear infections can lead to otitis media with effusion (OME or glue ear or serous otitis media). Children are asymptomatic apart from possible decreased hearing. The eardrum is seen to be dull and retracted, often with a fluid level visible (Fig. 16.2c). Confirmation of otitis media with effusion can be gained by a flat trace on tympanometry, in conjunction with evidence of a conductive loss on pure tone audiometry (possible if >4 years old), or reduced hearing on a distraction hearing test in younger children. Otitis media with effusion is very common between the ages of 2 and 7 years, with peak incidence between 2.5 and 5 years. This condition usually resolves spontaneously. Cochrane reviews have shown no evidence of long-term benefit from the use of antibiotics, steroids or decongestants. Otitis media with effusion is the most common cause of conductive hearing loss in children and can interfere with normal speech development and result in learning difficulties in school. In such children insertion of ventilation tubes (grommets, Fig. 16.2d) can be beneficial, but there is evidence, again from Cochrane reviews, that adenoidectomy can offer more long-term benefit. It is believed that the adenoids can harbour organisms within biofilms that contribute to infection spreading up the Eustachian tubes. In addition, grossly hypertrophied adenoids may obstruct and affect the function of the Eustachian tubes, leading to poor ventilation of the middle ear and subsequent recurrent infections. In practice, children with recurrent URTIs and chronic glue ear that do not resolve with conservative measures undergo grommet insertion. If these problems recur after grommet extrusion, reinsertion of grommets with adjuvant adenoidectomy is usually advocated.

Sinusitis

Infection of the paranasal sinuses may occur with viral URTIs. Occasionally there is secondary bacterial infection, with pain, swelling and tenderness over the cheek from infection of the maxillary sinus. As the frontal sinuses do not develop until late childhood, frontal sinusitis is uncommon in the first decade of life. Antibiotics and analgesia are used for acute sinusitis in addition to topical decongestants. There is some recent evidence that the concurrent use of intranasal corticosteroids or antihistamines together with antibiotics hasten recovery.

Tonsillectomy and adenoidectomy

Children with recurrent tonsillitis are often referred for removal of their tonsils, one of the commonest operations performed in children. Many children have large tonsils but this in itself is not an indication for tonsillectomy, as they shrink spontaneously in late childhood.

The indications for tonsillectomy are controversial, and must be balanced against the risks of surgery, but include:

Like the tonsils, adenoids increase in size until about the age of 8 years and then gradually regress. In young children, the adenoids grow proportionately faster than the airway, so that their effect of narrowing the airway lumen is greatest between 2 and 8 years of age. They may narrow the posterior nasal space sufficiently to justify adenoidectomy. Indications for the removal of both the tonsils and adenoids are controversial but include:

Croup

With laryngotracheobronchitis, usually called croup, there is mucosal inflammation and increased secretions affecting the airway, but it is the oedema of the subglottic area that is potentially dangerous in young children because it may result in critical narrowing of the trachea. Viral croup accounts for over 95% of laryngotracheal infections. Parainfluenza viruses are the commonest cause, but other viruses, such as human metapneumovirus, RSV and influenza, can produce a similar clinical picture. Croup occurs from 6 months to 6 years of age but the peak incidence is in the second year of life. It is commonest in the autumn. The typical features are a barking cough, harsh stridor and hoarseness, usually preceded by fever and coryza. The symptoms often start, and are worse, at night.

When the upper airway obstruction is mild, the stridor and chest recession disappear when the child is at rest. The child can usually be managed at home. The parents need to observe the child closely for the signs of increasing severity. The decision to manage the child at home or in hospital is influenced not only by the severity of the illness but also by the time of day, ease of access to hospital and the child’s age (with a low threshold for admission for those <12 months old, due to their narrow airway caliber), and parental understanding and confidence about the disorder.

Inhalation of warm moist air is widely used but is of unproven benefit. Oral dexamethasone, oral prednisolone and nebulised steroids (budesonide) reduce the severity and duration of croup, and the need for hospitalisation.

In severe upper airways obstruction, nebulised epinephrine (adrenaline) with oxygen by facemask provides transient improvement. Close monitoring, along with the advice of an anaesthetist or intensivist, is imperative due to the risk of rebound symptoms once the effects of the epinephrine (adrenaline) diminish after about 2 h. Only a few children with croup require tracheal intubation since the introduction of steroid therapy. Some children have a pattern of recurrent croup, which may be related to atopy.

Bacterial tracheitis (pseudomembranous croup)

This rare but dangerous condition is similar to severe viral croup except that the child has a high fever, appears toxic and has rapidly progressive airways obstruction with copious thick airway secretions. It is caused by infection with Staphylococcus aureus. Treatment is by intravenous antibiotics and intubation and ventilation if required.

Acute epiglottitis

Acute epiglottitis is a life-threatening emergency due to the high risk of respiratory obstruction. It is caused by H. influenzae type b. In the UK and many other countries, the introduction of universal Hib immunisation in infancy has led to a >99% reduction in the incidence of epiglottitis and other invasive H. influenzae type b infections.

There is intense swelling of the epiglottis and surrounding tissues associated with septicaemia. Epiglottitis is most common in children aged 1–6 years but affects all age groups. It is important to distinguish clinically between epiglottitis and croup (Table 16.1), as they require quite different treatment.

The onset of epiglottitis is often very acute (see Case History 16.1), with:

In contrast to viral croup, cough is minimal or absent. Attempts to lie the child down or examine the throat with a spatula or perform a lateral neck X-ray must not be undertaken as they can precipitate total airway obstruction and death.

If the diagnosis of epiglottitis is suspected, urgent hospital admission and treatment are required. A senior anaesthetist, paediatrician and ENT surgeon should be summoned and treatment initiated without delay. The child should be transferred directly to the intensive care unit or an anaesthetic room, and must be accompanied by senior medical staff in case respiratory obstruction occurs. The child should be intubated under controlled conditions with a general anaesthetic. Rarely, this is impossible and urgent tracheostomy is life-saving. Only after the airway is secured should blood be taken for culture and intravenous antibiotics such as cefuroxime started. The tracheal tube can usually be removed after 24 h and antibiotics given for 3–5 days. With appropriate treatment, most children recover completely within 2–3 days. As with other serious H. influenzae infections, prophylaxis with rifampicin is offered to close household contacts.

Case History

16.1 Acute epiglottitis

This 5-year-old girl developed a severe sore throat, drooling of saliva, a high fever and increasing difficulty breathing over 8 h (Fig. 16.4a) Epiglottitis was diagnosed and her airway was guaranteed with a nasotracheal tube. Antibiotics were started immediately (Fig. 16.4b,c). She made a full recovery.

Whooping cough (pertussis)

This is a highly contagious respiratory infection caused by Bordetella pertussis. It is endemic, with epidemics every 3–4 years. After a week of coryza (catarrhal phase), the child develops a characteristic paroxysmal or spasmodic cough followed by a characteristic inspiratory whoop (paroxysmal phase). The spasms of cough are often worse at night and may culminate in vomiting. During a paroxysm, the child goes red or blue in the face, and mucus flows from the nose and mouth. The whoop may be absent in infants, but apnoea is a feature at this age. Epistaxis and subconjunctival haemorrhages can occur after vigorous coughing. The paroxysmal phase lasts 3–6 weeks. The symptoms gradually decrease (convalescent phase) but may persist for many months. Complications of pertussis, such as pneumonia, convulsions and bronchiectasis, are uncommon, but there is still a significant mortality, particularly in infants. Infants who have not yet completed their primary vaccination at 4 months are particularly susceptible. Infants and young children suffering severe spasms of cough or cyanotic attacks should be admitted to hospital and isolated from other children.

The organism can be identified early in the disease from culture of a per-nasal swab, although PCR is more sensitive. Characteristically, there is a marked lymphocytosis (>15 × 10⁹/L) on a blood count. Although erythromycin eradicates the organism, it decreases symptoms only if started during the catarrhal phase. Siblings, parents and school contacts may develop a similar cough, and close contacts should receive erythromycin prophylaxis, and unvaccinated infant contacts should be vaccinated. Immunisation reduces the risk of developing pertussis and the severity of disease in those affected, but does not guarantee protection. The level of protection declines steadily during childhood.

Summary

Clinical features

Coryzal symptoms precede a dry cough and increasing breathlessness. Feeding difficulty associated with increasing dyspnoea is often the reason for admission to hospital. Recurrent apnoea is a serious complication, especially in young infants. Infants born prematurely who develop bronchopulmonary dysplasia or with other underlying lung disease, such as cystic fibrosis or have congenital heart disease, are most at risk from severe bronchiolitis. The characteristic findings on examination (Fig. 16.5) are:

Investigations

Respiratory viruses are now usually identified by PCR analysis of nasopharyngeal secretions. A chest X-ray is unnecessary in straightforward cases, but if performed, typically shows hyperinflation of the lungs due to small airways obstruction, air trapping (Fig. 16.6) and often focal atelectasis. Pulse oximetry is used to measure and monitor arterial oxygen saturation continuously. Blood gas analysis, usually a capillary sample, is only performed in severe disease to identify hypercarbia when additional ventilatory support is considered.

Management

This is supportive. Humidified oxygen is delivered via nasal cannulae; the concentration required is determined by pulse oximetry. The infant is monitored for apnoea. Mist, antibiotics, steroids and nebulised bronchodilators, such as salbutamol or ipratropium, have not been shown to reduce the severity or duration of the illness. Fluids may need to be given by nasogastric tube or intravenously. Assisted ventilation in the form of nasal or facemask CPAP or full ventilation is required in a small percentage of infants admitted to hospital. RSV is highly infectious, and infection control measures, particularly good hand hygiene, are needed to prevent cross-infection to other infants in hospital.

Prognosis

Most infants recover from the acute infection within 2 weeks. However, as many as half will have recurrent episodes of cough and wheeze (see below). Rarely, usually following adenovirus infection, the illness may result in permanent damage to the airways (bronchiolitis obliterans).

Prevention

A monoclonal antibody to RSV (palivizumab, given monthly by intramuscular injection) reduces the number of hospital admissions in high-risk preterm infants. Its use is limited by cost and the need for multiple intramuscular injections.

Clinical features

Fever and difficulty in breathing are the commonest presenting symptoms, usually preceded by an upper respiratory tract infection. Other symptoms include cough, lethargy, poor feeding and an ‘unwell’ child. Localised chest, abdominal, or neck pain is a feature of pleural irritation and suggests bacterial infection.

Examination reveals tachypnoea, nasal flaring and chest indrawing – the best clinical sign of pneumonia in children is increased respiratory rate, and pneumonia can sometimes be missed if the respiratory rate is not measured in a febrile child (so-called ‘silent pneumonia’). There may be end-inspiratory respiratory coarse crackles over the affected area, but the classic signs of consolidation with dullness on percussion, decreased breath sounds and bronchial breathing over the affected area are often absent in young children. Oxygen saturation readings may be decreased; this is an indication for hospital admission.

A chest X-ray may confirm the diagnosis, but with the exception of a classic lobar pneumonia characteristic of Streptococcus pneumoniae (Fig. 16.7), a chest X-ray cannot differentiate between bacterial and viral pneumonia. In younger children, a nasopharyngeal aspirate is useful to identify viral causes, but blood tests, including full blood count and acute-phase reactants, are generally unhelpful in differentiating between a viral and bacterial cause. A small proportion of pneumonias are associated with a pleural effusion, where there may be blunting of the costophrenic angle on the chest X-ray. Some of these effusions develop into empyema and fibrin strands may form, leading to septations, which make drainage difficult (Fig. 16.8). The incidence of childhood empyema has risen over the last decade, the precise reason for which remains unclear. Ultrasound of the chest will often distinguish between parapneumonic effusion and empyema.

Management

Evidence-based guidelines for the management of pneumonia in childhood have been published (British Thoracic Society). Most cases can be managed at home, but indications for admission include oxygen saturation <93%, severe tachypnoea and difficulty breathing, grunting, apnoea, not feeding or family unable to provide appropriate care. General supportive care should include oxygen for hypoxia and analgesia if there is pain. Intravenous fluids should be given if necessary, to correct dehydration and maintain adequate hydration and salt balance. Physiotherapy has no role.

The choice of antibiotic is determined by the child’s age, severity of illness and appearance on chest X-ray. Newborns require broad-spectrum intravenous antibiotics. Most older infants can be managed with oral amoxicillin, with broader-spectrum antibiotics such as co-amoxiclav being reserved for those who are complicated or unresponsive. For children >5 years of age, either amoxicillin or an oral macrolide such as erythromycin is the treatment of choice.

Parapneumonic effusions usually resolve with appropriate antibiotics, but the small proportion that develop an empyema require drainage of the collection. This may be achieved by either placement of a chest drain with or without the installation of a fibrinolytic agent in the intrapleural space (e.g. urokinase) to break down any septations, or by surgical decortication. Practices vary between different centres.

Prognosis

Follow-up is not generally required for children with simple consolidation on chest X-ray and who recover clinically. Those with evidence of lobar collapse, atelectasis or empyema should have a repeat chest X-ray after 4–6 weeks. Virtually all children with pneumonia, even those with empyema, make a full recovery.

Summary

Transient early wheezing

Most wheezy preschool children have virus-associated wheeze (also known as episodic viral wheeze and wheezy bronchitis). Transient early wheezing is thought to result from small airways being more likely to narrow and obstruct due to inflammation and aberrant immune responses to viral infection. This gives the condition its episodic nature, being triggered by viruses that cause the common cold. Studies have found that transient early wheezers often have decreased lung function from birth, from small airway diameter. Risk factors include maternal smoking during and/or after pregnancy and prematurity. A family history of asthma or allergy is not a risk factor. Transient early wheezing is more common in males and usually resolves by 5 years of age, presumably from the increase in airway size.

Persistent and recurrent wheezing

Some children, both preschool and school-aged, have frequent wheeze triggered by many stimuli. The presence of IgE to common inhalant allergens, such as house dust mite, pollens or pets, is associated with persistence of wheezing beyond the preschool years. Recurrent wheezing associated with evidence of allergy to one or more inhaled allergens (e.g. by skin-prick test or IgE blood test) is termed ‘atopic asthma’. Atopic wheezers have persistent symptoms and decreased lung function. Atopic asthma is strongly associated with other atopic diseases such as eczema, rhinoconjunctivitis and food allergy, and is more common in those with a family history of such diseases.

A small number of persistent or recurrent wheezing children will have other causes, such as the non-atopic asthmatics. Other causes of recurrent wheeze are listed in Box 16.2.

Investigations

Asthma can usually be diagnosed from the history and examination and no investigations are needed. Sometimes, specific investigations are required to confirm the diagnosis, or explore the severity and phenotype in more detail. Skin-prick testing for common allergens is often considered both as an aid to the diagnosis of atopy and to identify allergens which may be acting as triggers. A chest X-ray is usually normal but may help to rule out other conditions. If there is uncertainty, recording peak expiratory flow rate (PEFR) may be useful. Most children over 5 years of age can use a peak flow meter. Uncontrolled asthma leads to increased variability in peak flow, with both diurnal variability (morning PEFR usually lower than evening PEFR) and day-to-day variability (change in PEFR over the course of a week). Often, response to treatment is the most helpful investigation. This can be assessed if necessary by measuring the PEFR before and after inhaling a bronchodilator; it should increase by more than 10–15%.

Summary

Management

The aim of management is to allow the child to lead as normal a life as possible by controlling symptoms and preventing exacerbations, optimising pulmonary function, while minimising treatment and side-effects. It is important to set the aims with the child as they are more likely to comply with their therapy if they are involved in their management. An evidence-based and regularly updated British Guideline on Asthma Management gives guidance on asthma treatment in children and adults.

Medications used to treat children with asthma are shown in Table 16.2.

Bronchodilator therapy

Inhaled β₂-agonists are the most commonly used and most effective bronchodilators. Short-acting β₂–agonists (often called relievers) such as salbutamol or terbutaline have a rapid onset of action, are effective for 2–4 h and have few side-effects. They are used as required for increased symptoms, and in high doses for acute asthma attacks.

In contrast, long-acting β₂-agonists (LABAs) such as salmeterol or formoterol are effective for 12 h. They are not used in acute asthma, and should not be used without an inhaled corticosteroid. LABAs are useful in exercise-induced asthma.

Ipratropium bromide, an anticholinergic bronchodilator, is sometimes given to young infants when other bronchodilators are found to be ineffective, or in the treatment of severe acute asthma.

Inhaled corticosteroids

Prophylactic drugs are effective only if taken regularly. Inhaled corticosteroids (often called preventers) are the most effective inhaled prophylactic therapy. They decrease airway inflammation, resulting in decreased symptoms, asthma exacerbations and bronchial hyperactivity. They are increasingly used in conjunction with an inhaled LABA. They have no clinically significant side-effects when given in conventional licensed doses. They can produce systemic side-effects, including impaired growth, adrenal suppression and altered bone metabolism, when high doses are used.

Add-on therapy

The first choice of add-on therapy in a child over 5 years is a LABA, whereas in children under 5 years, an oral leukotriene receptor antagonist such as montelukast is recommended. The latter can also be used in older children when symptoms are not controlled by the addition of a LABA. Slow-release oral theophylline is an alternative; however, it has a high incidence of side-effects (vomiting, insomnia, headaches, poor concentration), so it is not commonly used in children.

Other therapies

Oral prednisolone, usually given on alternate days to minimise the adverse effect on height, is required only in severe persistent asthma where other treatment has failed. All children on this therapy must be managed by a specialist in childhood asthma. Anti-IgE therapy (omalizumab) is an injectable monoclonal antibody that acts against IgE, the natural antibody that mediates allergy. It is used for the treatment of severe atopic asthma, and should only be administered by a specialist in childhood asthma.

Most antibiotics are of no value in the absence of a bacterial infection, although recent data suggest that macrolide antibiotics (e.g. erythromycin) may have a specific role in asthma management, but neither cough medicines nor decongestants are helpful. Antihistamines, e.g. loratadine and nasal steroids, are useful in the treatment of allergic rhinitis.

The British Guideline on Asthma Management uses a stepwise approach, starting treatment with the step most appropriate to the severity of the asthma. Treatment increases from step 1 (mild intermittent asthma) to step 5 (chronic severe asthma requiring continuous or frequent use of oral steroids), stepping down when control is good (Fig. 16.12).

Allergen avoidance and other non-pharmacological measures

Although asthma in many children is precipitated or worsened by specific allergens, complete avoidance of the allergen is difficult to achieve. The value of identifying such triggers by history or allergy testing is controversial. There is currently no conclusive evidence that allergen avoidance measures (such as removal of furry animals or using dust mite impermeable mattress covers) are beneficial, although they may be considered in selected cases. Allergen immunotherapy is effective for treating atopic asthma, but its use is limited by the risk of systemic allergic reactions associated with the treatment (see Ch. 15).

Parents should be advised about the harmful effects of cigarette smoking in the house. Although exercise improves general fitness, there is no evidence that physical training improves asthma itself. Psychological intervention may be useful in chronic severe asthma.

Exercise-induced asthma

Some children’s asthma is brought on only by vigorous exercise. With appropriate treatment, asthma should not restrict exercise, and there are many elite athletes with asthma. For most, a short-acting β₂-agonist bronchodilator taken immediately before exercise is sufficient, but if there are more marked symptoms a LABA taken in conjunction with an inhaled steroid will give greater protection. A LABA should not be prescribed without an inhaled steroid.

Choosing the correct inhaler

Inhaled drugs may be administered via a variety of devices, chosen according to the child’s age and preference:

• Pressurised metered dose inhaler (pMDI) and spacer (Fig. 16.13).

– Appropriate for all age groups: 0–2 years, spacer and facemask; >2 years, spacer alone

– A spacer is recommended for all children as it increases drug deposition to the lungs

– Useful for acute asthma attacks when poor inspiratory effort may impair the use of inhalers direct to the mouth

• Breath-actuated metered dose inhalers (e.g. Autohaler, Easibreath): 6+ years. Less coordination needed than a pMDI without spacer. Useful for delivering β-agonists when ‘out and about’ in older children

• Dry powder inhaler: 4+ years (Fig. 16.14). Needs a good inspiratory flow, therefore less good in severe asthma and during an asthma attack. Also easy to use when ‘out and about’ in older children

• Nebuliser: any age (Fig. 16.15). Only used in acute asthma where oxygen is needed in addition to inhaled drugs; occasionally used at home as part of an acute management plan in those with rapid-onset severe asthma (brittle asthma).

Many children fail to gain the benefit of their treatment because they cannot use the inhaler correctly. This must be demonstrated and the child’s ability to use it checked. In young children, parents need to be skilled in assisting their child to use the inhaler correctly. Assessing and reassessing inhaler technique is vital to good management and should be a routine part of any review.

Criteria for admission to hospital

Children require hospital admission if, after high-dose inhaled bronchodilator therapy, they:

A chest X-ray is indicated only if there are unusual features (e.g. asymmetry of chest signs suggesting pneumothorax, lobar collapse) or signs of severe infection. In children, blood gases are only indicated in life-threatening or refractory cases.

Management

Acute breathlessness is frightening for both the child and the parents. Calm and skilful management is the key to their reassurance. High-dose inhaled bronchodilators, steroids and oxygen form the foundation of therapy of severe acute asthma.

Management is summarised in Figure 16.16. As soon as the diagnosis has been made, the child should be given a β₂-bronchodilator. For severe exacerbations, high-dose therapy should be given and repeated every 20–30 min. For moderate to severe asthma, 10 puffs of β₂-bronchodilator should be given via a pressurised metered dose inhaler (pMDI) and large volume spacer. This is not only good treatment but also educates the child and parent in using the preferred devices they will have at home. For severe to life-threatening asthma, a β₂-bronchodilator may need to be given via nebuliser driven by high-flow oxygen. The addition of nebulised ipratropium to the initial therapy in severe asthma is beneficial. Oxygen is given when there is any evidence of arterial oxygen desaturation, such as saturations of <92%. A short course (2–5 days) of oral prednisolone expedites the recovery from moderate or severe acute asthma.

Intravenous therapy has a role in the minority of children who fail to respond adequately to inhaled bronchodilator, either aminophylline or intravenous salbutamol. For intravenous aminophylline, a loading dose is given over 20 min, followed by continuous infusion. Seizures, severe vomiting and fatal cardiac arrhythmias may follow a rapid infusion. If the child is already on oral theophylline, the loading dose should be omitted. With both aminophylline and salbutamol, the ECG should be monitored and blood electrolytes checked. There is increasing evidence that intravenous magnesium sulphate is helpful in life-threatening asthma. Antibiotics are only given if there are clinical features of bacterial infection. Occasionally, these measures are insufficient and artificial ventilation is required.

Patient education

Prior to discharge from hospital after an acute admission, the following points should be reviewed with the child and family:

The child and parents need to know that increasing cough, wheeze and breathlessness, and difficulty in walking, talking and sleeping, or decreasing relief from bronchodilators all indicate poorly-controlled asthma. Some asthmatics find it difficult to identify gradual deterioration – measurement of peak flow rate at home allows earlier recognition. Patients with troublesome asthma are usually given a supply of oral steroids to keep at home, with instructions in the asthma action plan on when to start them.

Summary

Respiratory management

Recurrent and persistent bacterial chest infection is the major problem. In younger children, respiratory status is monitored on symptoms; older children should have their lung function measured regularly by spirometry. The FEV₁ (forced expiratory volume in 1 second), expressed as a percentage predicted for age, sex and height, is an indicator of clinical severity and declines with disease progression.

With regular treatment, most infants and children with CF should have no respiratory symptoms, and often have no abnormal signs. From diagnosis, children should have physiotherapy at least twice a day, aiming to clear the airways of secretions. In younger children, parents are taught to perform airway clearance at home using chest percussion and postural drainage. Older patients perform controlled deep breathing exercises and use a variety of physiotherapy devices for airway clearance. Physical exercise is beneficial and is encouraged.

Many CF specialists recommend continuous prophylactic oral antibiotics (usually flucloxacillin), with additional rescue oral antibiotics for any increase in respiratory symptoms or decline in lung function. Persisting symptoms or signs require prompt and vigorous intravenous therapy to limit lung damage, usually administered for 14 days via a peripheral venous long line. Increasingly, parents are taught to administer courses of intravenous antibiotics at home, so decreasing disruption of normal activities such as school. Chronic Pseudomonas infection is associated with a more rapid decline in lung function, and this is slowed by the use of daily nebulised antipseudomonal antibiotics. Nebulised DNAse or hypertonic saline may be helpful to decrease the viscosity of sputum and so increase its clearance. The macrolide antibiotic azithromycin, given regularly, decreases respiratory exacerbations, probably due to an immunomodulatory effect rather than antibiotic action. Regular, nebulised hypertonic saline may decrease the number of respiratory exacerbations.

More severe CF requires more regular intravenous antibiotic therapy. If venous access becomes troublesome, implantation of a central venous catheter with a subcutaneous port (e.g. Portacath) simplifies venous access, although they require monthly flushing and complications may develop.

Bilateral sequential lung transplantation is the only therapeutic option for end-stage CF lung disease. Fortunately, this is rarely required during childhood. Outcomes following lung transplantation continue to improve with >50% survival at 10 years. Meticulous assessment, for example with regard to comorbidities and microbiology, psychological preparation, optimal timing of transplantation and expert post-transplant care, are all essential parts of the multidisciplinary transplant process.

Nutritional management

Dietary status should be assessed regularly. Pancreatic insufficiency is treated with oral enteric-coated pancreatic replacement therapy taken with all meals and snacks. Dosage is adjusted according to clinical response. A high-calorie diet is essential, and dietary intake is recommended at 150% of normal. To achieve this, overnight feeding via a gastrostomy is increasingly used. Most patients require fat-soluble vitamin supplements.