Kim Pollard and Anita Watson.Jan 2001. Bronchodilators [online]. Seacroft University Hospital, UK. Available from http://www.cysticfibrosismedicine.com

Testing for airway reversibility in patients with cystic fibrosis is important. In Leeds patients undergo a formal reversibility challenge where the best of three FEV1 measurements (if possible) are recorded before and 15 minutes after 5 mg nebulised salbutamol (or 5 mg terbutaline) (Conway et al 1997). Patients should not have taken any inhaled or nebulised bronchodilators in proceeding 12 hours. If an individual patient is unable to tolerate 5 mg of salbutamol we would reduce the dose to 2.5 mg on subsequent testing or try 5 mg of terbutaline. For the patient to be considered a responder there must be an increase in FEV1 of > 15% and or an equivalent increase in FEF25-75 . Changes in FEV1 of > 20% suggest asthma. Those individuals with a smaller but significant improvement in FEV1 following beta-agonist challenge (10% to 15%) should be considered for regular bronchodilators and/or inhaled corticosteroids. In symptomatic patients who are unresponsive to beta-agonists then an anticholinergic agent can be tested with the FEV1 being measured before and 30 minutes after nebulisation. Some patients tolerate terbutaline a lot better than salbutamol (unpublished data). Half the CF patients have some degree of bronchial lability which will improve with a bronchodilator (Holzer et al, 1981; Eggleston et al, l988).

Airway dilatation before physiotherapy helps in the clearance of chest secretions. For this reason bronchodilators are often given prior to physiotherapy. Salbutamol (Ventolin) or terbutaline (Bricanyl) are usually used. They may be combined (even mixed) with an inhaled steroid such as budesonide (Pulmicort).

Bronchodilators in standard doses are free from serious side effects although mild tremor and hypokalaemia may develop in some patients. Slight reversible narrowing of the bronchial tubes is so common, even in babies (Kraemer, 1989), that some clinics recommend all CF patients should have a nebulised bronchodilator before physiotherapy. However each patient should be formally assessed as some patients can develop increasing symptoms with bronchodilators with worsening of lung function. Patients should be tested regularly with a bronchodilator to determine if they have bronchial lability as the response varies from time to time in individual patients and appears more severe when the infection is more active, improving with antibiotic treatment. Patients who have significant reversibility may benefit from regular inhaled steroids. A chart of the twice-daily peak expiratory flow rates (the best of 3 PEF) is a useful method of measuring the severity of bronchial lability and monitoring the effects of any new treatment.

Bronchodilators may alternatively be given by metered dose inhalers through a spacer device. The long acting b -agonist salmeterol can be and has been shown to improve respiratory function in two-thirds of adult patients with bronchial lability (Bargon et al, 1996). High doses of salmeterol can improve lung function in hospitalised patients (Hordvik et al, 1999). Eformoterol can be used as an alternative to salmeterol.

Antibiotics (with-T-piece)

Bronchodilators

Pulmozyme

References

Bargon I, Viel K, Wiewrodt R, Caspary W, Buhl R. Efficacy of nebulised salmeterol in the treatment of adult patients with cystic fibrosis. Israel J Med Sci 1996; 32 Suppl; S221

Egglesston PA, Rosenstein BJ, Stackhouse CM, Alexander MF. Airway hyperreactivity in cystic fibrosis. Clinical correlates and possible effects on the course of the disease. Chest 1988; 94: 360-365

Conway SP, Watson A. Nebulised bronchodilators, corticosteroids and rhDNase in adult patients with cystic fibrosis. Thorax 1997; 52(Suppl 2): 564-568

Holzer FJ, Olinsky A, Phelan PD. Variability of airways hyperreactivity and allergy in cystic fibrosis. Arch Dis Child 1981; 56: 455-459

Hordvik NL, Sammut PH, Judy CG, Colombo JL. Effects of standard and high doses of salmeterol on lung function of hospitalised patients with cystic fibrosis. Pediatr Pulmonol 1999; 27: 43-53.

Kraemer R. Early detection of lung function abnormalities in infants with cystic fibrosis. J R Soc Med 1989; 82 (Suppl 16): 21-25

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