Treatment of childhood asthma

MBBS(Ceylon), DCH(Ceylon), DCH(England), MD(Paediatrics), FRCP(Edinburgh), FRCP(London), FRCPCH(United Kingdom), FSLCPaed, FCCP, FCGP(Sri Lanka) Consultant Paediatrician

Asthma is an inflammatory disorder of the airways characterised by narrowing of the air tubes brought on by swelling of the lining of the airway, contraction of the muscles of the airways and increased secretion of mucus or "phlegm". In the case of children, asthma is such a variable disorder that there are many considerations that need to be gauged when one looks at the treatment options that could be used. There is a very wide spectrum of clinical presentation of asthma ranging from mild infrequent attacks through moderately severe and frequent episodes to acute severe life-threatening events. Careful assessment is essential before tangible decisions are made regarding further management and the use of certain medications.

One component of treatment is the management of an acute attack. There are several drugs which are so very useful in controlling an acute episode but judicious decisions have to be made regarding their use. Initial assessment of the severity of the attack is the determining factor for the selection of drugs. This initial evaluation is used to classify the episode as a mild attack, a moderately severe attack or an acute severe attack. The last could be so severe that the presence of certain features would further categorise it as a life-threatening attack. This is a harbinger of death and urgent intensive treatment is absolutely essential to save life. All these assessments need to be done by an experienced doctor using features of the history of the illness, its progression, past history and the findings on clinical examination.

The first requirement for a moderately severe or an acute severe attack is the provision of added oxygen through either a mask or through nasal prongs. The airway narrowing leads to marked interference with ventilation of the lungs that the necessary amounts of life-giving oxygen are not allowed to be provided to the blood and thereby to the tissues of the body. The only initial solution to this problem, at least till one could take steps to correct the narrowing of the airways is to provide an additional increased amount of oxygen into the lungs. Parents often get frightened by medical staff starting a child on oxygen but it is more or less a precautionary measure. Most people believe that added oxygen is given only to a dying patient. This is not true and there are several other instances where added oxygen may be used. Steps must be taken to explain this to the parents or care-givers, allay their anxiety and provide reassurance.

Then there are the drugs that are so useful to treat the acute episode and relieve the airway narrowing. Their action is centred around dilatation of the narrowed airways. These drugs are therefore known by the collective term "relievers". There are several different groups of medications that fall into this category. Some of them need to be given by inhalation, either by using a nebuliser or via a spacer device attached to a metered dose inhaler which is commonly known by the name of "puffer". The advantage of these methods is that only tiny doses need to be used as the drug is directly provided to the lung where its primary effect is required. Some of these drugs could also be given by mouth but then much larger doses need to be used. The oral use is generally employed only for very mild attacks. Many people also believe that these children who are once nebulised will always need nebulisation. This too is not true and there is no scientific basis for this belief. Nebulisation and other forms of inhalation therapy is used for the moderately severe and severe attacks as it is so very effective and the observable clinical effect comes on within minutes. The other advantage is that inhalation therapy could be repeated at very frequent intervals as and when necessary. The general side effects that are seen when the same drug is given by mouth are generally not seen as frequently with inhalation therapy. Inhaled therapy is quite safe in the acute phase of the attack and this is so even when the procedure has to be repeated at frequent intervals. It certainly has no adverse effects on the heart.

There are other reliever drugs that are used through the intravenous route. These are generally used when inhaled therapy fails to control the acute attack. Some of these drugs, just like those used for inhalation therapy, act quite quickly but prolonged treatment in the form of intravenous infusions may be necessary to maintain the achieved dilatation of the airways. There are several drugs that fall into this category and some newer drugs are being increasingly used. All these drugs work by different mechanisms of action, the effects are generally complementary when more than one drug needs to be used and the end results are quite good. It is however imperative that proper doses are used to obtain the best effect.

In markedly severe cases, drugs belonging to the corticosteroid group may need to be used. However, it must be remembered that these medicines take about 4 to 6 hours to produce optimal effect. They could be given orally or through the intravenous route. In severe cases, the latter route of administration is preferred. They act by suppressing the inflammatory response of the airways and this process necessarily takes time. Steroids may need to be continued for up to a week in certain instances. Such short courses of steroids are safe and do not have long-lasting undesirable side effects on the child.

In most acute episodes, ancillary treatment measures are also quite important. If the child is hospitalised, good nursing, attention to good quality nutrition and adequate hydration are essential. The latter is of marked significance as rapid breathing induced by the attack leads to a loss of water from the body via exhaled breath. If it is not possible for the child to drink because of the severity of the episode of asthma, replenishment of the fluid losses should be by the intravenous route. In the case of suspected bacterial infections precipitating the acute attack of asthma, it may be necessary to use antibiotics but it must be stressed that this is perhaps uncommon and the use of antibiotics is certainly not a panacea for all ills in asthma.

Once the acute episode has been brought under control, it is time to assess the need for further long-term treatment. There are several drugs available today which, when used prudently, help to prevent recurrences of asthma. These drugs are therefore known as "preventers". However, these decisions are not to be made lightly as preventive treatment is a protracted form of therapy and needs to be continued for quite some time. There are certain features that suggest that the child may benefit from these forms of treatment. Children with what is known as persistent asthma with some degree of airway narrowing virtually every day, those who get very frequent attacks that interfere with normal life, children with acquired chest deformities as a result of asthma, those with marked exercise induced asthma, those who have growth retardation as a result of asthma, those who have significant disturbance of schooling as a result of asthma, those who are prone to get acute severe episodes of asthma and those who suffer from troublesome nocturnal asthma and persistent night cough that interferes with sleep are the ones in whom preventive therapy may be considered. In addition, those who have poor access to medical care, especially at night too, may be considered for primarily social reasons. The rationale for this is that severe attacks at night may cause a lot of problems and perhaps may even cause death.

There are some oral drugs that may be used for preventive therapy but these are effective only in some cases and are not quite useful in severe forms of the disease. However, some of them may be quite useful in combinations with other forms of preventive therapy, especially in severe and difficult to control cases. In today’s context, the "gold standard" for preventive therapy is the use of inhaled corticosteroids. Only very small doses of these steroids need to be used as the drug is delivered directly to the lungs and as such general effects on the rest of the body are not of any significant consequence. In the recommended doses, even long-term treatment with inhaled corticosteroids is safe. The effectiveness of these drugs depends on their anti-inflammatory action as it counteracts the very basic disturbance in childhood asthma which is inflammation of the airways. All preventive medications have to be given even when the child is quite well as they work purely for prevention and most of them are not useful during acute attacks.

There are several different formulations of inhaled corticosteroids and different inhaler devises that could be used in children. There are some dry powder inhalers that could be usefully employed in older children. The child has to inhale the very fine powder into the lungs. However, the most useful form if inhaler in children is the metered dose inhaler or "puffer". When each dose is actuated, a jet of gas containing the effective dose of the drug is ejected. The only problem is that the speed of ejection is very high, around 70 miles per hour and most children, and for that matter, even adults, find it impossible to synchronise their intake of the breath with the actuation of the device to ensure that the drug is inhaled properly. To get over this problem a holding chamber or "spacer" needs to be used. This device is connected to the puffd the child breathes in and out normally at the other end of the spacer after the puffer is actuated and the dose of medicine is put into the spacer. One-way valve systems ensure that the breaths that are put out do not get into the spacer. In the case of children, they need to be trained under direct medical supervision on the proper technique of the use of all these devices. The parents too must observe and learn all necessary details of these forms of treatment. All inhalers have a finite number of doses and it is useful to write down the date of starting a fresh inhaler on the inhaler device label itself so that a new inhaler could be purchased when all the contained doses have been used up. Many parents wait till the inhaler device completely finishes and is no longer able to eject, before purchasing a new one. This is a mistake as, beyond the total number of doses that are specified in the device, there is only the propellant gas that is emitted. The active drug is available only for the total specified number of ejections.

Whatever the device, it is best to rinse the mouth with water and throw out this water each time inhaled steroids are used. This is to ensure that some of the drug that is deposited in the mouth is not swallowed. All spacer devices need cleaning from time to time and there are special ways in which these need to be cleaned. Vigorous rubbing of the inside of the spacers should be avoided as this interferes with the normal working of the device. Proper advice regarding the use of all inhaler devices should be given by the prescribing doctor and time taken to explain the different aspects of inhalation therapy is time well spent to guarantee proper utilisation of the drug and ensuring optimal effectiveness of these forms of treatment.

Preventive therapy has to be carried out under medical supervision. These children need regular assessment by the prescribing doctors from time to time. The dosage may be reduced by the doctor once control of the disease has been obtained and the child remains well for a reasonable period of time. The dosages may also need to be increased to deal with special situations and when the disease appears to be getting out of control. These are not drugs that could be continued by the parents without regular medical direction. Haphazard changes in dosage, keeping off doses from time to time and abrupt stoppage of treatment should be scrupulously avoided. It must be remembered that the disease is being kept under control by these drugs and the child may develop an unprotected acute severe attack if the drugs are suddenly withdrawn. There is no truth whatsoever in the commonly held belief that patients tend to get addicted to these inhalers. These drugs are used simply because the asthmatic state is of considerable concern which requires their use and there is no risk of addiction to them.

P.S. Boost your immunity against asthma by eating Vitamin C and Vitamin D rich foods and fruits.

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