The areas covered by the guideline are: the use of peak flow measurement in diagnosis and management, drug treatment, non-drug treatment and referral.
All recommendations are for primary health care professionals and apply to adult patients attending general practice with asthma. The development group assumes that health care professionals will use general medical knowledge and clinical judgement in applying the general practice principles and specific recommendations of this document to the management of individual patients. Recommendations may not be appropriate for use in all circumstances. Decisions to adopt any particular recommendation must be made by the practitioner in the light of available resources and circumstances presented by individual patients.
Recommendation:
Higgins et al. (1989) studied a population which included those with chest disease. The 95th centile and above was defined by a 25% or greater variability in peak flow.
Quackenboss et al. (1991) studied 861 adults and children who were screened to exclude those with chest disease. In the remaining group peak flow was measured four times daily and used to define population centiles. The 95th centile and above was defined by a 19% or greater variability in peak flow.
Quackenboss, J.J., Lebowitz, M.D. and Krzyzanowski, M. (1991) Normal range of diurnal changes in peak expiratory flow rates: relationship to symptoms and respiratory disease. American Review of Respiratory Disease 143:323-330.
Recommendations:
the routine home use of peak flow meters for self
Statement: the routine home use of peak flow meters does not alter patient outcomes (I).
GRASSIC (1994) studied 569 patients who were randomly allocated to routine care or to have a peak flow meter plus guidelines - they were followed for 12 months. There was no significant difference between the groups except those with peak flow meters used more oral steroids though this was within the more severe patients.
Grampian Asthma Study of Integrated Care (GRASSIC) (1994) Effectiveness of routine self monitoring of peak flow in patients with asthma. British Medical Journal 308: 564-567.
Bellia et al. (1985) showed in 38 patients with morning dips compared with controls and followed for 2 years that morning dipping is a transient phenomenon reflecting current control rather than long-term prognosis.
Nowak et al. (1982) looked at 109 patients attending emergency rooms and measured pre-treatment and post-treatment peak flow, need for admission and followed up those patients discharged from the emergency room without admission. They defined poor outcome as having to be admitted or having poor control of their asthma in the 48 hours after leaving the emergency room. A pre-treatment peak flow of less than 100 l/min, a post-treatment peak flow of less than 300 l/min, and an improvement in peak flow of less than 60 l/min all predicted poor outcome.
What is the role of chest X-ray in patients newly presenting in primary care?
What is the role of peak flow in predicting outcome in acute situations in UK primary care?
Which patients should be monitored with regular peak expiratory flow rate measurements and when?
A further general statement from the British Thoracic Society guidelines that is relevant at this point is that it is preferable to adjust treatment to cover exposure to day to day triggers, such as exercise and cold air, because avoidance imposes inappropriate restrictions on lifestyle. Specific comments about adjusting the dosages of drugs are made within the relevant sections on drug treatment.
Kings Fund Centre, National Asthma Campaign, Royal College of General Practitioners, General Practitioners in Asthma Group, British Association of Accident and Emergency Medicine, and British Paediatric Respiratory Group (1993) Guidelines on the management of asthma. Thorax 48:s1-s24.
Drugs
used in the treatment of recurrent wheeze
All recommendations for treatment apply only in the absence of recognised contra-indications, side-effects or interactions as documented in the BNF.
Compliance
Recommendation:
Recommendations:
Orgel et al. (1985) showed that salbutamol is effective when used as a Rotahaler.
Taylor et al. (1993) studied 64 adults, taking either fenoterol 400 micro g four times daily or matching placebo in a double blind study of two 24 week periods . During each period they had a fenoterol inhaler to use as required. During the time they were on placebo, the subjects had fewer exacerbations of asthma, better FEV1 and morning peak flow, and less bronchial hyper-reactivity. The results suggest that doses of short acting beta 2 agonists should only be taken as required.
Chapman et al. (1994) studied 341 asthmatics (of whom 313 completed the trial) who took either 200 g of salbutamol four times daily or matching placebo for two weeks, then crossed over to the alternative. During each period they had a salbutamol inhaler to use as required. During regular salbutamol dosing, there were fewer "asthma episodes" and less requirement for supplemental salbutamol. There was no difference in morning or evening peak flow. This study appears to show that regular usage of beta 2 agonists is preferable to p.r.n..
Taylor, D.R., Sears, M.R., Herbison, G.P., Flannery, E.M., Print, C.G., Lake, D.C., Yates, D.M., Lucas, M.K. and Li, Q. (1993) Regular inhaled beta agonist in asthma: effects on exacerbations and lung function. Thorax 48:134-138.
Rohr et al. (1987) studied 80 patients with exercise induced bronchospasm in a randomised parallel group study comparing sodium cromoglycate with salbutamol. The sodium cromoglycate group took 20 mg four times daily for four weeks and then a single dose 15 minutes before a treadmill test; the salbutamol group took salbutamol p.r.n. for four weeks and a dose 15 minutes before the exercise test. The reduction in FEV1 was significantly smaller with salbutamol (17%) than sodium cromoglycate (27%).
What are the appropriate points at which to increase and decrease treatment with short acting beta 2 agonists?
Long acting inhaled beta 2 agonists
Recommendations:
Fitzpatrick et al. (1990) compared salmeterol 50 micro g twice daily with salmeterol 100 micro g twice daily and with placebo in 20 asthmatics. Nocturnal peak flow fall was improved on both doses of salmeterol and sleep quality improved on 50 g twice daily.
Palmer et al. (1992) conducted a double blind parallel group study comparing salmeterol 50 micro g twice daily with salmeterol 100 micro g twice daily, with no placebo. Grouped data showed greater benefits in peak flow, symptoms, and rescue bronchodilator use with the larger dose of salmeterol, but this is partly due to baseline differences and there were also more side-effects on the bigger dose.
Bronsky et al. (1994) studied 154 subjects randomised to one of four doses of salmeterol or placebo for one week. The higher doses of salmeterol (50 micro g twice daily and 100 micro g twice daily) produced significant bronchodilatation (FEV1) for 12 hours; lesser doses did not. There were more side-effects on the 100 micro g twice daily dose.
Fitzpatrick, M.F., Mackay, T., Driver, H. and Douglas, N.J. (1990) Salmeterol in nocturnal asthma: a double blind, placebo controlled trial of a long acting inhaled beta 2 agonist. British Medical Journal 301:1365-1368.
Palmer, J.B., Stuart, A.M., Shepherd, G.L. and Viskum, K. (1992) Inhaled salmeterol in the treatment of patients with moderate to severe reversible obstructive airways disease: a 3-month comparison of the efficacy and safety of twice-daily salmeterol (100 micro g ) with salmeterol (50 micro g ). Respiratory Medicine 86:409-417.
Pearlman et al. (1992) studied 234 asthmatics randomised to three groups: placebo; salbutamol 180 micro g four times daily; salmeterol 42 micro g twice daily. Patients were followed for 12 weeks and approximately one third of each group were on inhaled steroids. In terms of symptoms and lung function measurements, salmeterol appeared superior to salbutamol which was superior to the placebo. There was no tolerance to the bronchodilating effects of salmeterol.
Britton et al. (1992) studied 534 subjects who completed a comparison of salmeterol 50 micro g twice daily with salbutamol 200 g four times daily for three months, and then a further nine months in which salmeterol was given with the same dosage and salbutamol was given 200 micro g twice daily; 37% were on high dose inhaled steroids and 26% on low dose. Most of the comparisons in the paper look at the first three months treatment and show that salmeterol was superior in terms of nocturnal asthma symptoms, morning and evening peak flow readings.
Lundback et al. (1993), in a study design the same as that of Britton et al. (1992) used dry powder inhalers instead of metered dose inhalers; 57% of patients were on inhaled steroids, 5% on oral steroids and 7% on both. 388 asthmatics were included in this study and again salmeterol was superior in terms of peak flow readings, nocturnal symptoms, and also rescue beta 2 agonist use.
Britton, M.G., Earnshaw, J.S. and Palmer, J.B. (1992) A twelve month comparison of salmeterol with salbutamol in asthmatic patients. European Study Group [published erratum appears in Eur Respir J 1993;6(1):150]. European Respiratory Journal 5:1062-1067.
Lundback, B., Rawlinson, D.W. and Palmer, J.B. (1993) Twelve month comparison of salmeterol and salbutamol as dry powder formulations in asthmatic patients. European Study Group. Thorax 48:148-153.
Pearlman, D.S., Chervinsky, P., LaForce, C., Seltzer, J.M., Southern, D.L., Kemp, J.P., Dockhorn, R.J., Grossman, J., Liddle, R.F., et al. (1992) A comparison of salmeterol with albuterol in the treatment of mild to moderate asthma. New England Journal of Medicine 327:1420-1425.
Castle et al. (1993) studied over 25,000 patients in general practice who were randomised to salmeterol 50 micro g twice daily or salbutamol 200 micro g four times daily for 16 weeks. The primary outcome was mortality; there were more deaths in the salmeterol group but this did not reach significance. Only 69% of the patients were on inhaled steroids.