Copyright ©ERS Journals Ltd 2004 Safety of research bronchoscopy, biopsy and bronchoalveolar lavage in asthma1 Dept of Respiratory Medicine, London Chest Hospital, and 2 Lung Pathology, Dept of Gene Therapy, Imperial College School of Medicine, Royal Brompton Hospital, London, UK CORRESPONDENCE: N.C. Barnes, Dept of Respiratory Medicine, London Chest Hospital, Bonner Road, London, E2 9JX, UK. Fax: 44 2089832279. E-mail: neil.barnes@bartsandthelondon.nhs.uk Keywords: Adverse events, asthma, biopsy, bronchoalveolar lavage, bronchoscopy
Received: June 5, 2003
Financial support was provided by the British Lung Foundation, GlaxoSmithKline, Astra Zeneca, Merck and departmental funds.
Bronchoscopy with endobronchial biopsy (EBB) and/or bronchoalveolar lavage (BAL) has become an important research tool in asthma. A recent report has suggested audit and reporting of the safety of these procedures. A total of 159 asthmatic patients (84 males, 75 females), aged 1852 (median 27) yrs, forced expiratory volume in one second 53120 (median 88) % predicted, underwent 273bronchoscopies in six clinical research studies. On 228 occasions, EBB and BAL were performed and, on 45 occasions, EBB was performed alone. On 48 occasions, bronchoscopy was performed 24 h post-allergen challenge. Adverse events occurred on 34 out of 273 occasions, none of which were following allergen challenge. Post-EBB and BAL, four patients developed pleuritic chest pain, shortness of breath and fever. A further two patients experienced pleuritic chest pain alone post-EBB/BAL. Bronchospasm or worsening of asthma symptoms occurred on 14 occasions, 13 post-EBB/BAL and on one occasion post-EBB alone. Fever/flu-like symptoms were reported on nine occasions following EBB and BAL. One subject had haemoptysis post-EBB/BAL, but required no intervention. In conclusion, bronchoscopy, endobronchial biopsy and bronchoalveolar lavage can be performed safely in asthmatic patients. Most of the complications were seen where bronchoalveolar lavage and endobronchial biopsy were both performed, suggesting that bronchoalveolar lavage accounts for most of the adverse events. Fibreoptic bronchoscopy with endobronchial biopsy (EBB) or bronchoalveolar lavage (BAL) has become an important tool in asthma research over the last two decades. These techniques have led to significant advances in the understanding of the pathogenesis of asthma and, in particular, the role of inflammatory cells and mediators 14. In addition, intervention studies with new and existing treatments have provided useful insight into the mechanisms of action and efficacy of these treatments 57. Following initial concerns over the safety of these techniques in asthmatic patients 8, 9, consensus guidelines were published by the National Heart, Lung and Blood Institute 10, 11. More recently, three papers have reported bronchoscopy to be safe and well-tolerated in a relatively small number of asthmatic patients 1214. Despite this, concerns still remain and a recent report has suggested audit and continued reporting of the safety of these procedures. The current authors report their experience of adverse events related to fibreoptic bronchoscopy performed in asthmatic subjects taking part in six clinical research studies.
Study subjects A total of 159 patients with asthma (84 males, 75 females), forced expiratory volume in one second (FEV1) 53120 (median 88) % predicted, aged 1852 (median 27) yrs were recruited for six studies and underwent a total of 273 bronchoscopies. On 228 occasions, subjects underwent EBB and BAL, 48 of which were performed 24 h post-allergen challenge. On 45 occasions, subjects had EBB alone. Subjects were recruited from chest clinics at the London Chest and Royal Brompton Hospitals (London, UK), advertisements in local press and from primary care. Ethics committee approval for each study was obtained from the research ethics committees of the relevant hospitals and each subject gave written informed consent. Eligible subjects were males or females, aged 1852, with a clear clinical history of asthma, reversible airflow obstruction spontaneously or following ß2-agonists, histamine provocative concentration causing a 20% fall in FEV1 (PC20) <8 mg or a history of mild asthma precipitated by an aeroallergen (entry criteria depending on the individual study). PC20 was measured for three of the studies; for one study, the data was not recorded, but entry criteria included a PC20<4 mg. For the other two studies, PC20 ranged from 0.066.0 (median 1.0). In the multicentre studies, only subjects who underwent bronchoscopy at the London Chest Hospital or the Royal Brompton Hospital are included in this report. Study 1 was a multicentre, double-blind, randomised, placebo-controlled, parallel group study using an anti-interleukin-5 monoclonal antibody. This study required subjects to undergo two bronchoscopies, with EBB and BAL 8 weeks apart 15. Study 2 was a multicentre, randomised, double-blind, placebo-controlled parallel group study investigating the effects of zafirlukast and beclomethasone dipropionate on allergen-induced airway inflammation. Subjects underwent bronchoscopy with EBB and BAL on two occasions 8 days apart and, on the second occasion, the bronchoscopy was performed 24 h post-allergen challenge 16. Study 3 was a randomised, placebo-controlled study to examine whether cyclosporin A inhibited allergen-induced airway inflammation. Subjects underwent two bronchoscopies with EBB and BAL 3 days apart; the second was performed 24 h post-allergen challenge 17. Study 4 was a multicentre, randomised, placebo-controlled comparison of the effects of oral pranlukast on bronchial mucosal immunopathology. Subjects underwent two bronchoscopies with EBB and BAL 12 weeks apart. Study 5 was a single-centre study to compare the inflammatory profile in asthmatic smokers and nonsmokers. Subjects had one bronchoscopy with EBB alone. Study 6 was a randomised, double-blind, placebo-controlled study investigating the effects of montelukast on eosinophils in bronchial biopsy specimens. Subjects underwent two bronchoscopies with EBB and BAL 6 weeks apart.
Bronchoscopy
Adverse events occurred on 34 out of 273 occasions; none of these were following allergen challenge (table 1
Four patients developed pleuritic chest pain, fever and shortness of breath within 1224 h of EBB and BAL. Two ofthese had changes on chest radiograph consistent with pneumonitis and required hospital admission. They were treated with i.v. antibiotics, to cover possible infection, and nebulised bronchodilators and were discharged after 2 days. Oral antibiotics were continued to complete a 1-week course. One patient experienced pleuritic chest pain and breathlessness 24 h post-procedure when, as a result of technical problems with suction equipment during BAL, only 10% ofthe BAL fluid was recovered. These symptoms were associated with a fall in FEV1 from 88% to 70% pred. Symptoms and spirometry resolved within 6 days without any treatment. One patient experienced chest pain and shortness of breath with no radiological changes and no treatment was required. Two further patients experienced pleuritic chest pain alone, without fever or dyspnoea. Bronchoconstiction episodes or worsening of asthma symptoms occurred on 14 occasions, 13 post-EBB/BAL and once post-EBB alone. On two occasions, the patient experienced problems during the procedure, and the procedure was terminated to allow treatment with nebulised bronchodilators and i.v. steroids. On six occasions, the symptoms occurred prior to discharge and required treatment with nebulised bronchodilators, and six subjects experienced an increase in symptoms within 2448 h post-discharge and required the additional use of inhaled salbutamol for 325 days. Fever or flu-like symptoms were reported on nine occasions following EBB and BAL. On each occasion, the symptoms that started 1224 h after the procedure were short-lived andsettled spontaneously with no treatment in 25 days. Nonspecific chest discomfort occurred on two occasions post-EBB/BAL. A minor haemoptysis occurred on one occasion post-EBB/BAL; the subject was admitted for observation overnight and no treatment was required. Two patients reported general lethargy/malaise for 1 week post-bronchoscopy, one after EBB alone and one post-EBB/BAL.
In this paper, the current authors have demonstrated thatresearch bronchoscopy, including BAL and EBB, has an acceptable safety profile in asthmatics of mild-to-moderate severity. To our knowledge, this is the largest series reporting the safety of research bronchoscopies in asthmatic subjects. Alow incidence of adverse events has been found and it hasbeen shown that the procedure is well-tolerated by the majority of subjects. Most of the adverse events experienced by the studied patients were minor, requiring no specific treatment and with no prolonged morbidity. On two occasions following bronchoscopy with biopsy andBAL, subjects required hospital admission. On each occasion, they complained of pleuritic chest pain and fever, and developed chest radiograph infiltrates consistent with a diagnosis of pneumonitis. Treatment was instituted with i.v. antibiotics to cover possible infection and both subjects were fit to be discharged after 2 days. There were no long-term sequelae in either case. On a further nine occasions, patients reported fever or flu-like symptoms. These events are not specific to asthmatic patients; fever following bronchoscopy is well-recognised, with previous studies estimating an incidence of 1.216% 18, 19 for all bronchoscopic procedures and an incidence of 2.550% amongst patients undergoing BAL 20, 21. In the current patients, only those undergoing BAL experienced fever or pneumonitis, and subjects who only had biopsy performed reported only nonspecific side-effects, such as mild deterioration in asthma symptoms and general lethargy. This would suggest that BAL accounts for the majority of adverse events and, although a direct comparison cannot be made as a result of the relatively small numbers of subjects undergoing biopsy alone, this is in keeping with the findings of Humbert et al. 14 who observed a trend towards a smaller reduction in peak expiratory flow when only biopsies were taken. No adverse events were reported in the 48 patients who hadbronchoscopy post-allergen challenge, suggesting that bronchoscopy can be safely performed following allergen challenge. This is consistent with previous studies. Gianorio et al. 22 showed that BAL performed either 4 or 24 h post-allergen challenge neither deteriorated lung function nor increased airway responsiveness in a group of atopic patients with a history of rhinitis and/or bronchial asthma. Bronchoscopy with endobronchial biopsy and/or bronchoalveolar lavage has become an important research tool. It can be performed safely and is well-tolerated by asthmatic subjects. Continued surveillance and reporting of the use of these techniques is recommended.
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