| COPD | Asthma | |
| Smoker or ex-smoker | Nearly all | Possibly |
| Symptoms under age 35 | Rare | Often |
| Chronic productive cough | Rare | Often |
| Breathlessness | Persistent and progressive | Variable |
| Night time waking with breathlessness and and/or wheeze | Uncommon | Common |
| Significant diurnal variation or day-to-day variability | Uncommon | Common |
Tag Archives: asthma
Clinical features differentiating COPD and asthma (NICE 2010)
Nebuliser Therapy
Most respiratory conditions are treated with an inhaled drug. This enables the drug to effectively target the receptors in the lungs.
Although the nebulising unit of air compressor, mask, chanmber and tubing is commonly referred to as the nebuliser, it’s actually the small contraption attached to the mask which contains the fluid which is the nebuliser. It is this that transforms the liquid drug into fine aerosol. In many cases, inhalers employed with spacers and the proper technique are as effective, or more effective as nebulisers. This may be because of the inefficiency of the method with around 12% of the drug actually reaching the target receptors. This depends on the patients’ breathing rate and depth, the health and age of the patients’ lungs, the volume of the drug being administered and the type of nebuliser chamber. The nebuliser chamber, its components, and air flow rate, determine the size of droplets produced. If the droplet size is too small, the drug will end up in the peripheries of the lungs which decreases the efficacy of the drug. Overfilling the chamber will also affect efficacy as well as prolonging the time taken to administer; this should be 5-10 minutes. Once the nebuliser has finished there is likely to be a small residue of the drug in the chamber.
Nebulisers are not generally indicated for mild-moderate asthma because it has been shown that this can often lead to an overuse of bronchodilators rather than preventers.
Nebulisers are used to administer anticholinergics, corticosteroids, bronchodilators, antifungals and antibiotics as well as recombinant human deoxyribonuclease (used to increase expectoration and reduce viscosity in cystic fibrosis patients). If the nebuliser is used with antibiotics or corticosteroids a mouthpiece should be used to avoid contact with the skin and eyes.
Generally nebulisers are no more efficient than inhalers, and in fact some inhaled drugs are not available in nebuliser form, they can promote over-dependence on bronchodilators in asthmatics and also be habit-forming if the patient enjoys the cooling sensation. It is, however, helpful for patients with reduced manual dexterity or patients receiving palliative care.
Asthma
It is estimated that around 10% of the UK population have some degree of asthma. Frequently people do not get treatment because they feel it is something they just have to live with, not realising that effective treatment is readily available. Patient education coupled with pharmacological intervention can mean that asthma is well-controlled and has little or no impact in a person’s life.
When a patient reports respiratory problems, it’s vital to obtain a history, exploring if the patient has had any breathlessness, how serious it is (impeding ability to speak in complete sentences, for example), roughly how long the episodes last, how many there have been, and also if the patient detected any trigger for the episode; likewise the same factors should be considered for any episodes of wheezing, coughing (including products of the cough), and tightness in the chest or discomfort, and any rhinitis. Family history of respiratory problems should assessed and the patient’s occupation should also be noted to assess likelihood of occupational asthma.
Diagnosis of asthma is based on the symptoms expressed, the patient’s history, and the reversibility of the airways. The asthma may be allergic or non-allergic. If allergic sensitivity may be found to dust mites, pollen, mould or animals. Asthma can also be triggered by pollutants, smoke, climatic changes or as a response to a viral illness.
A family history of asthma, eczema or rhinitis can help towards an asthma diagnosis.
Peak flow can be checked during the consultation, however, if asthma is exercise or allergy induced it is possible that a normal result could be achieved. Giving the patient a peak flow meter to use at home and asking the patient to fill in a brief peak flow diary can help to diagnose the problem. Peak flow is a practical measure of how bad an episode is and how well medication is working. Explaining the use and technique of peak flow, also advising on inhaler technique is good practice for the initial consultation (if necessary for the patient). If there is a peak flow variability of 20% or more after using a bronchodilator, or during a week of peak flow diary recordings, this provides supporting evidence of an asthma diagnosis, differentiating it from COPD.
It may be prudent to start a patient on inhaled steroids as well as a bronchodilator; some asthma deaths have been linked to overuse of bronchodilators, also a bronchodilator alone may not be sufficient for the patient. If a person experiences a few symptoms frequently, it is unlikely that a bronchodilator alone would control the condition.
Inhaled steroids (beclometasone, fluticasone, or budesonide) are all suitable for patients with either an exacerbation of asthma over the past two years, if the patient is having interrupted sleep one or more nights per week, if the patient is experiencing symptoms three or more times a week or if the patient is using an inhaled beta 2 agonist three or more times a week. Sodium cromoglicate requires qds administration and therefore is not always practical, so it is generally not used as a first-line treatment.
Admission to hospital is indicated if the adult patient has a pulse higher than 100 beats/minute, unable to speak in full sentences, respiratory rate above 25 breaths/minute or peak flow is 50% below normal/predicted.
Asthma is considered life-threatening if peak flow is 33% below predicted, oxygen saturation is below 92%, cyanosis is present, patient is hypotensive, arterial partial pressure is O2<8kPa, patient is bradycardic, exhausted, hypotensive, confused, has feeble respiratory effort, has dysrrhythmia or a silent chest or, obviously, is in a coma.
Steroids are indicated in such situations; they can be given intra-muscularly or orally (IM route takes 6 hours to take effect, oral takes 8 hours) route choice is down to personal preference.
A high dose (30-40mg) of an oral steroid, prednisalone is indicated in such cases for seven days after the acute episode.
Pregnancy will not necessarily have an impact on asthma, and asthma medications have not been found to harm the mother or unborn baby. It is important for mother and baby that the asthma is well-controlled throughout the pregnancy. If it is not, the mother is at greater risk of complications such as pre-eclampsia, hypertension, hyperemesis gravidarum, premature birth, increased prenatal mortality, intrauterine haemorrhage.
To reduce acute exacerbations of asthma and hospital admissions it is important that each patient has their own personal action plan, that they have received sufficient help and advice, that their peak flow and inhaler techniques are regularly checked and that their peak flow is routinely checked in the surgery. When the patient presents, it is worthwhile to check on their inhaler use and how many episodes of waking in the night they’ve had, how often they have asthma symptoms and how this affects their everyday life.
