Recognising and managing an acute asthma attack

Asthma attacks are potentially life threatening and characterised by a reversible narrowing of the airways, they affects 1.1 million children in the UK (Asthma UK, 2021a). Approximately 25 000 children are admitted to hospital as an emergency per year because of asthma attacks (NHS London, 2020). In 2018, 20 children under the age of 14 died from asthma, while 22 between the ages of 15–24 years old died (Royal College of Paediatrics and Child Health, 2020). Therefore, it is important to be able to recognise asthma attacks and initiate appropriate management.

‘Formal diagnosis of asthma is difficult and must reflect the chronic nature of the disease…There is no one test that confirms a diagnosis of asthma. GPs use a combination of clinical history and lung function testing…any child who presents as acutely unwell with wheeze should be treated as though they have asthma’

What is asthma?

Asthma is a chronic condition characterised by sporadic attacks and a day-to-day variation in the patient's respiratory function.

During an asthma attack, activation of the immune system triggers a spasming of the upper airways (bronchospasm) and inflammation around all airways in the lungs (Schofield et al, 2019). This limits the amount of air that reaches the alveoli and, therefore, oxygen that reaches the blood.

Attacks are triggered by well-defined causes, including pets, dust, or cold weather (Box 1)(NHS England, 2018; Asthma UK, 2021b). Following exposure to these stimuli, antibodies trigger a chain reaction amongst immune cells, causing a release of histamine and other inflammatory chemicals.

Box 1.Common asthma triggers

• Exercise
• Infections
• Mould or damp
• Smoke, fumes and pollution
• Medicines, especially non-steroidal anti-inflammatory drugs and aspirin
• Emotions, including stress
• Dust or mites
• Animal fur or feathers
• Pollen
• Cold weather
• Cleaning products
• Deodorants
• Recreational drugs
• Before or during menstruation

Diagnosing asthma attacks

The hallmarks of an asthma attack are difficulty breathing and wheeze. However, wheeze is not always caused by asthma. As a result of their relatively narrow airways, children are more prone to wheeze when their lungs are stressed, for example during a viral infection. This is different from asthma as the wheeze happens as a one off, rather than repeatedly, and there is no day-to-day variation in their respiratory function. In the acute setting, it is difficult to tell the difference between these conditions and asthma. However, it is of limited importance as the initial management is the same. Formal diagnosis of asthma is difficult and must reflect the chronic nature of the disease (National Institute of Health and Care Excellence [NICE], 2020). There is no one test that confirms a diagnosis of asthma. GPs use a combination of clinical history and lung function testing (Tang et al, 2019). The diagnosis of an acute asthma attack is clinical and any child who presents acutely unwell with wheeze should be treated as though they have an asthma attack. In chronic asthma, there is a day-to-day variation in the child's respiratory function. Clinicians will look for evidence of this in the history and by measuring peak expiratory flow at set points during the day for several weeks. Furthermore, the inflammatory process involved in asthma generates nitrous oxide; the child's breath can be tested for this and, if present, a diagnosis of asthma can be made (NICE, 2020).

‘Day-to-day treatment of asthma revolves around two types of medication, relievers and preventers. For relievers, children will be prescribed inhalers, to take when they have symptoms related to breathing difficulty and wheeze.’

Management of chronic asthma

Day-to-day treatment of asthma revolves around two types of medication, relievers and preventers. For relievers, children will be prescribed inhalers, to take when they have symptoms related to breathing difficulty and wheeze. The aim of this medication is just to treat that exacerbation. For preventers, children will be prescribed daily medication, usually inhaled, to try and prevent exacerbations. Based on how frequently a child has to use their reliever inhaler, they are categorised into different ‘steps’, where less than twice a week is considered to be ‘good control’ (British Thoracic Society, 2019). Short-acting bronchodilators are used as reliever therapy, including ipratropium bromide. Preventer treatment starts with inhaled corticosteroids in most cases, before other treatments are considered (British Thoracic Society, 2019).

Features of an asthma attack

During an attack, sudden onset bronchospasm and airway swelling make it harder for the child to move air into their alveola. In severe cases, this will result in inadequate amounts of oxygen entering the blood, meaning the organs do not receive enough oxygen to function properly. Initially, the child will work hard to compensate by breathing faster and using extra muscles. Hopefully, with treatment or time, the airway swelling and spasm will reverse. However, attacks can progress rapidly.

If an attack does not improve, then aft er a sustained period of oxygen deprivation, the child will start to decompensate; their organs will stop functioning properly, they will become exhausted and they will be unable to breathe harder. At this point, they are in critical position and, without significant medical intervention, will quickly lose consciousness and die (Papiris et al, 2009). Chronic exacerbation of asthma occurs if the child's control worsens and the frequency of attacks increases.

Categorisation

The severity of asthma attacks varies greatly, some result in mild wheeze, while other attacks are life threatening. To provide clarity, there are four categories of attack, mild, moderate, severe and life threatening, with clearly defined criteria for each (Box 2) (NICE, 2020). The criteria are particularly important for facilitating early recognition of severe and life threatening asthma, allowing early escalation of treatment.

Box 2.Criteria for categorising asthma attacksModerate acute asthma

• Able to talk in sentences
• Arterial oxygen saturation (SpO₂)≥92%
• Peak flow≥50% best or predicted
• Heart rate≤140/minute in children aged 1–5 years; heart rate≤125/minute in children aged over 5 years
• Respiratory rate≤40/minute in children aged 1–5 years; respiratory rate≤30/minute in children aged over 5 years

Severe acute asthma

• Cannot complete sentences in one breath or too breathless to talk or feed
• SpO₂<92%
• Peak flow 33–50% best or predicted
• Heart rate>140/minute in children aged 1–5 years; heart rate>125/minute in children aged over 5 years
• Respiratory rate>40/minute in children aged 1–5 years; respiratory rate>30/minute in children aged over 5 years

Life-threatening acute asthmaSevere asthma plus one of the following:

• SpO₂<92%
• Peak flow<33% best or predicted
• Silent chest
• Cyanosis
• Poor respiratory effort
• Hypotension
• Exhaustion
• Confusion

(NICE, 2020)

Symptoms

The characteristic symptoms of an asthma attack are difficulty in breathing, cough and wheeze, oft en but not always occurring quickly after exposure to a known asthma trigger (Lissauer and Claydon, 2012). It is important to ask the child what they were doing when their symptoms started and what potential triggers they were exposed to.

Typically, the child will find it harder to breathe and will feel tight chested. Usually, they will have a wheeze; a high-pitched whistling sound heard during breathing caused by lower airway obstruction. In milder cases, this can be heard at the end of breathing out (end expiratory wheeze). As the severity increases, the wheeze is heard through expiration and, in very severe cases, it can be heard at all times. Children also often have a cough during an asthma attack, which starts at the same time as their other symptoms.

Not being able to breathe can result in the child being anxious or distressed as it is very unpleasant. However, as the attack progresses and they begin to tire, they might become drowsy as they struggle to get enough oxygen to their brain; this is a life-threatening symptom.

Although the management of any wheeze is very similar regardless of cause, it is worth asking questions to try and find out how likely it is that an attack is because of asthma (Box 3). This is because true asthma is much more likely than other causes of wheeze to progress into life-threatening airway obstruction, so a more cautious approach is needed.

Box 3.Important questions to ask during an asthma history

• When did your symptoms start?
• Where were you?
• What where you doing?
• Do you have a temperature?
• Do you have a cough and do you bring anything up when you cough?
• How did you feel first thing this morning?
• Have you ever had anything like this before? If so, what triggered it?
• Have you been diagnosed with asthma?
• What medication do you usually take for it?
• Have you been taking it recently?
• Are you allergic to anything?
• When did you last have to use your preventer?
• How many times a week do you have to use your preventer?
• Do you know your normal peak expiratory flow?
• Have you ever been to hospital before because of your asthma?
• Have you ever been to an intensive therapy unit or been intubated before because of asthma?
• Do you or any of your family have hay fever, eczema or asthma?
• Do you smoke?

For some, it will be their first attack; however, most will have had similar symptoms before. Therefore, it is important to ask a number of questions:

• Has anything like this has happened before. If so, how often?
• What makes it happen?
• Have they been exposed to that this time?
• Have they been diagnosed with asthma? If so, what is their asthma control like? Questions to assess asthma control can include ‘when did you last have a similar attack?’ ‘How many attacks have you had in the last week/month?’
• What inhalers have they been prescribed? This will give an idea of how severe their asthma is
• Have they been taking their inhalers properly recently? This question should be accompanied by an explanation of how to take inhalers properly and a demonstration from the child of their technique, so it can be assessed (Box 5)
• Have they ever needed to go to hospital or intensive care and have they ever needed to be intubated? Previous intubation, or visits to an intensive therapy unit mean they have had a life-threatening asthma attack before and is concerning, this should lower the threshold for calling 999.

At this point, the main differential diagnoses are likely to be asthma, non-asthmatic wheeze and, potentially, a chest infection. An asthma attack is most likely if they have had similar episodes before, been diagnosed with asthma or have a family history of atopy. It is also more likely if they have just been exposed to a known trigger and if their recent inhaler compliance has been poor. A cough and shortness of breath could also be because of a chest infection. Patients with an infection would be expected to have a temperature and a cough productive of sputum, and it is unlikely that wheeze would be detected. Furthermore, the onset of an infection is generally more gradual than an asthma attack, which is sudden.

Signs

As with any acutely unwell patient, they should be assessed using the A–E format. Each problem should be treated as it is found, with classifying the attack to be an aim after assessment.

Visually, the child's airway should appear normal, however, it is important to listen for stridor. This is a high pitched noise heard during inspiration and, although similar to wheeze, it does sound different as it is one note (compared to the multiple notes in wheeze) and sounds harsher. Stridor is a sign of upper airway obstruction and is caused by conditions such as epiglottitis, not asthma, which is a lower airway disorder (Pfleger and Eber, 2016). Stridor is a medical emergency and the emergency services should be phoned immediately. At this point, it is important to note if the child is unconscious. If they are they are unlikely to be able to support their airway, this would need to be managed with either a head tilt chin lift and jaw thrust or any airway adjuncts that have been trained. If either of these things are necessary, it is vital to communicate this with the 999 call handler, as the child needs very urgent attention

Next, the patient's breathing should be assessed. It is good to start by recording observations, respiratory rate, oxygen saturation and the time. This will give an indication of how unwell the child is and can be referred back to later to see if an attack is improving or getting worse. Initial oxygen saturation in particular is vital to determining severity and further management; however, clinicians should note that normal saturation should not necessarily be reassuring and all criteria are important when determining the severity of asthma.

A more detailed breathing assessment will give further information about the severity of the attack. One test to measure severity is to see if the child can complete sentences in one breath; if they cannot, the attack should be classified as ‘severe’ (British Thoracic Society, 2020).

It is also important to assess their respiratory effort, to see how hard they are having to work to breathe. At first, the patient will naturally adopt a position that maximises the amount of air they are able to get into their lungs. They will sit up in bed and reach forward with their arms, this is known as ‘tripoding’ and is a sign they are finding it harder to breathe than normal (Zuriati et al, 2020).

In more severe attacks, they will have to work even harder to breathe and there will be examination findings that indicate respiratory distress. The patient will use muscles in their neck to try and help move the rib cage, these muscles can clearly be seen to contract and it is known as ‘using accessory muscles’. Tracheal tugging and intercostal recessions are also signs of respiratory distress. When the child breathes in, the skin will be tugged back towards the trachea or in between the ribs towards the lungs. This occurs during inspiration because the pressure in the lungs is lowered, but in this case, the space is not filled with air because of the airway obstruction, therefore, the skin gets pulled back towards the lungs.

Listening to the child's lungs will give further valuable information. The narrow airways disrupt airflow, causing turbulence, which leads to lots of different high-pitched noises as the child breathes. This is known as ‘polyphonic wheeze’ and is very characteristic of asthma.

An asthma attack is life threatening either when the child becomes fatigued and can no longer breathe or if their airway swelling or mucus production is so severe that it stops the movement of air into the lungs. There are several associated signs that it is important to look for. They will have a poor respiratory effort and on auscultation, nothing will be heard, as they are unable to move air into or out of their lungs. This is known as a ‘silent chest’. The lack of oxygen in their blood will cause their lips and tongues to become a dark shade of blue, known as ‘cyanosis’.

If the equipment and time is available, it is useful to take a peak expiratory flow reading (see Box 4)(Asthma UK, 2020a) as this will help categorise the asthma and will give an objective measurement to monitor the attack. However, this measurement should not be collected if it will delay lifesaving treatment.

Box 4.Correct technique for using a peak flow meter

• Push the dial back to zero
• Fit a new mouth piece
• Ask the child to sit or stand up
• Ask the child to take as deep a breath as they can
• Ask the child to blow out as hard as they can into the meter forming a good seal around the mouth piece
• Repeat the reading twice more and take their highest score

(Asthma UK, 2020a)

It is important to assess circulation. Heart rate is always valuable, as it gives an indication of how unwell a patient is and will help to categorise the asthma. It is also important to assess heart rhythm, as an irregular rhythm is a feature of life-threatening asthma. A slow central capillary refill time would also indicate the child is very sick. This is assessed by pressing down firmly on the sternum for 5 seconds and seeing how long it takes for blood to return to the area that has been pressed. It should become pink again in under 2 seconds, anything longer suggests that the child's circulation is compromised, a sign they are severely unwell.

Finally, the D part of the assessment should be reached, assessing the child's consciousness. It is a very concerning sign if they are starting to become drowsy, as this suggests they are becoming fatigued and will not be able to make as much respiratory effort. There are lots of videos on the internet showing examples of these signs for practitioners who are less familiar with them (see further information).

Treatment

The management of asthma is very well defined and follows a clear pathway. Once asthma has been considered, the initial priority should be to start initial treatment and categorise the attack. The emergency services should be contacted immediately if the attack is severe, life threatening or the clinician feels it is appropriate (NICE, 2020).

The majority of attacks are mild or moderate and can be managed in the community. The above criteria for categorising attacks should give a framework for clinicians and give them confidence to make decisions about who to refer to hospital and who to try and manage in the community. As always, if there are any concerns that the child should be referred to hospital, a practitioner should not hesitate to call 999, as gut instincts are often correct and should be listened to (Van den Bruel et al, 2012).

Management in the community

First-line management of an asthma attack is inhaled salbutamol, a short-acting bronchodilator that relaxes the muscles around the airways, making it easier to breathe. The child should have 2–10 puffs, depending on how severe the attack is. Salbutamol is a safe medication with few side effects, so there should be no hesitation in using it in a child with symptoms of asthma. If a child has too much, it might temporarily increase their heart rate and make them a bit shaky. The salbutamol should be administered via a spacer, using either the single breath and hold technique or the tidal breathing technique (Box 5)(Asthma UK, 2020b). It can be difficult to get the technique right, especially if the child is breathing quickly or is anxious. However, it is vitally important as it is only with the correct technique that the drug will reach the lungs. In severe asthma, this can be repeated every 10–20 minutes. If the child needs ten puffs every 10–20 minutes, 999 should be called. If the child does not respond to the first ten puffs, they should be referred to hospital. It is important to keep a record of how many doses the child has had and when, as it will enable monitoring how much medication the child has been given and how the child has responded to it.

Box 5.Correct inhaler and spacer techniqueThere are two possible methods:Single breath and hold

• Hold the inhaler upright and shake it
• Make sure the valve in the spacer is facing upright (if present)
• Remove any caps from the spacer and attach the inhaler
• Ask the child to sit or stand up with their chin slightly turned up
• Ask the child to breath out gently slowly away from the spacer until their lungs feel empty
• Ask the child to put their lips around the mouth piece of the spacer
• Press the inhaler once and ask the child to breath in steadily until their lungs feel full up
• Ask the child to take their lips away from the spacer, hold them in a tight seal and hold their breath for 10 seconds.
• Wait 30–60 seconds before administering the next dose

Tidal breathing

• Hold the inhaler upright and shake it
• Make sure the valve in the spacer is facing upright (if present)
• Remove any caps from the spacer and attach the inhaler
• Ask the child to sit or stand up with their chin slightly turned up
• Ask the child to breath out gently slowly away from the spacer until their lungs feel empty
• Ask the child to put their lips around the mouthpiece of the spacer and to start breath in and out steadily
• Press the inhaler as the child continues to breath
• After five breaths in and out remove the inhaler from their mouth
• Wait 30–60 seconds before administering the next dose

(Asthma UK, 2020b)

Another key intervention in the community is to optimise the child's position to make breathing as easy as possible. Sitting them up will make it significantly easier for them to move more air in and out of their lungs.

If the child responds to inhaled salbutamol, they should be kept for a period of observation before letting them go. It is important to consider what caused this attack and ensure they are not immediately re-exposed to it. For example, if a child's attack was precipitated by exercise on a cold day, they should not go back and join in with that session.

In severe or life-threatening asthma, ten puffs of salbutamol inhaler and oxygen should be given, if available, while waiting for the paramedics to arrive. If the child is finding it difficult to breathe or is unable to coordinate their breathing in the required manner, giving 2.5–5mg of nebulised salbutamol to the child can be even more beneficial, as the child does not have to actively do anything for it to work (KidsHealth, 2014).

In hospital

Ongoing management follows a stepped approach. It begins with back-to-back salbutamol and ipratropium. Ipratropium is another short-acting bronchodilator that works on different receptors. These are given via nebulisers, which turn the drugs into a mist. This is useful when the child is unable to perform inhaler technique correctly (KidsHealth, 2014).

If these treatments are unsuccessful, then oral or intravenous steroids are given, which decrease swelling and help open the airways. Typically, prednisolone is used orally and hydrocortisone intravenously. The dose depends on the child's age and weight. If steroids are given, they will usually be continued for 3 days to maximise recovery and minimise the chances of a rebound attack. A review will be arranged after 48 hours to check response and see if the patient requires further days on steroids (Normansell et al, 2016).

If there are any life-threatening features or the child does not respond to first-line management, urgent review by a critical care team is indicated (NICE, 2020). This is because there is a danger the child's airway might become compromised, and their inability to oxygenate may require them to be intubated for ventilation.

If a child has not responded to first-line medications, then intravenous magnesium sulphate can be given. This is an off-licence use of magnesium sulphate, however, research has shown it to be effective in treating asthma and safe if appropriate monitoring is in place (Albuali, 2014). If the child still has not responded, intravenous salbutamol may be considered by a critical care team.

Once the acute attack is under control, the child will be maintained with nebulisers and steroids. As their breathing improves, they will start to be weaned onto their discharge medication. Once a child manages salbutamol via inhaler every 4 hours, they are able to leave.

After the attack

It is important that the child's GP surgery is contacted after an attack, so they can be reviewed. Attacks can be the result of a failure of preventative therapy and, provided that issues such as poor compliance or technique have been ruled out, their preventer medication needs to be checked (NICE, 2020). This also creates a full picture of how frequently the child is having attacks. A single attack at school or during their after school activities might not raise concern at any one organisation, however, the GP or asthma nurse will be able to see that they have had three attacks close together.

Mitigating the risk

As asthma attacks are common and potentially life threatening, it is important schools take appropriate steps to ensure they respond well when a child has an attack. The school should have a policy about the management of asthma. The school nurse should have a record of every child with asthma, especially if they have been prescribed a preventer inhaler.

Preventer inhalers should never be locked away and children should be encouraged to keep them with them at all times. During activities that might exacerbate their asthma, their inhalers should be readily to hand. For example, on the side of the sports hall during a PE lesson. Staff should have an understanding of asthma, be able to recognise attacks and know when to ask for help from medically trained personnel. This is especially important for staff who are likely to lead higher risk activities, such as PE and DT.

Given the importance of early inhalers in the treatment of an asthma attack and the hectic nature of school life, it is good practice to prepare for the worst by having spare emergency salbutamol inhalers to hand around the school (Department of Health and Social Care, 2015). Not having an inhaler to hand when it is most needed could be disastrous. Ensuring there are inhalers available in key locations, such as sports halls, with the teacher supervising break time play, in the DT rooms and the nurse's room, is good practice that could end up saving a life.

Conclusion

Asthma attacks are caused by bronchospasm and airway swelling after exposure to asthma triggers. There are four different categories for an attack: mild, moderate, severe and life threatening. Mild and moderate asthma can usually be managed in the community, with inhaled salbutamol. Severe and life-threatening attacks need urgent hospitalisation, as they require high levels of medical support and treatment. Salbutamol and oxygen should be given while waiting for the emergency services. Early recognition of severe and life-threatening asthma is crucial in saving lives.

KEY POINTS

• Asthma is a chronic condition characterised by day to day variation in respiratory function. Patients with asthma can suffer from acute attacks.
• During an asthma attack the airways spasm and swell making it hard for the patient to breath. These can be potentially fatal.
• Because of the wide range of severity of asthma attacks it is very important to catagorise the attack into mild, moderate, sever and life threatening.
• Most asthma attacks are mild and moderate and can be managed in the community with inhaled salbutamol.
• Any child with features of sever or life threatening asthma requires immediate treatment and transfer to hospital.
• A child showing signs of fatigue or decreased respiratory effort is especially worrying as they have started to decompensate.

REFLECTIVE QUESTIONS

• What is asthma?
• What happens during an asthma attack?
• How do you classify asthma attacks?
• What are the two most concerning signs during and asthma attack?
• What is the treatment of asthma in the community?

FURTHER INFORMATION

• NICE guidelines https://www.nice.org.uk/guidance/ng80
• BTS/SIGN guidelines https://www.brit-thoracic.org.uk/quality-improvement/guidelines/asthma/
• Videos on concerning signs during assessment Wheeze: https://www.youtube.com/watch?v=7oTfvJff7go&t=18s
• Overview of attack: https://www.youtube.com/watch?v=EK8nzKzdnIM
• Respiratory distress: https://www.youtube.com/watch?v=U-RfbrnMJZE https://www.youtube.com/watch?v=EK8nzKzdnIM https://www.youtube.com/watch?v=NjDEimKwsJE https://www.youtube.com/watch?v=U5nrX-RN7hQ
• Stridor: https://www.youtube.com/watch?v=JSdEK79J4dw&t=10s https://www.youtube.com/watch?v=vDdJo0RPKa8