|Year : 2013 | Volume
| Issue : 4 | Page : 249-254
Utility of flexible fiber optic bronchoscopy: Experience from a tertiary care teaching hospital
Rahul Magazine, Shobitha Rao
Department of Pulmonary Medicine, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
|Date of Web Publication||26-Nov-2013|
Department of Pulmonary Medicine, Kasturba Medical College, Manipal University, Manipal - 576 104, Karnataka
Source of Support: None, Conflict of Interest: None
Aims: To identify the indications for flexible fiber optic bronchoscopy (FOB) and to compare the pre- and post-bronchoscopy diagnoses.
Settings and Design: A retrospective case record based study of 322 subjects who had been admitted in the different wards of a tertiary care teaching hospital in south India and had undergone flexible fiber bronchoscopy for various indications was conducted.
Materials and Methods: The demographic data, chest radiographic findings, pre-bronchoscopy suspected clinical diagnosis, bronchoscopy findings, microbiological results, pathological data, and post-bronchoscopy confirmed clinical diagnosis were recorded as per a pre-designed pro forma and analyzed. Results: The mean age of the patients was 52.99 years (SD ± 15.1, range: 17-82). The top three pre-bronchoscopy suspected clinical diagnoses were pulmonary tuberculosis (n = 129, 40%), lung malignancy (n = 99, 30.7%), and bacterial pneumonia (n = 57, 17.7%). The distribution of the clinical diagnoses post-bronchoscopy was as follows: Bacterial pneumonia (n = 58, 18%), lung malignancy (n = 56, 17.4%), and pulmonary tuberculosis (n = 28, 8.7%). FOB confirmed the diagnoses of lung malignancy, bacterial pneumonia, and pulmonary tuberculosis in 45.5%, 31.6%, and 18.6% of the respective suspected diagnostic categories. Twenty-four (85.7%) cases of confirmed pulmonary tuberculosis and 45 (80.4%) cases of confirmed lung malignancy were rightly suspected by the clinician prior to bronchoscopy. Overall, the diagnosis could be established in 142 (44.1%) cases with the help of FOB.
Conclusion: Bronchoscopy could establish a diagnosis in less than half of the cases. The commonest suspected pre-bronchoscopy clinical diagnosis was pulmonary tuberculosis, but the commonest confirmed post-bronchoscopy diagnosis was bacterial pneumonia. Lung malignancy category had the best correlation between pre-bronchoscopy and post-bronchoscopy diagnosis.
Keywords: Flexible bronchoscopy, lung malignancy, pneumonia, tuberculosis
|How to cite this article:|
Magazine R, Rao S. Utility of flexible fiber optic bronchoscopy: Experience from a tertiary care teaching hospital. J NTR Univ Health Sci 2013;2:249-54
|How to cite this URL:|
Magazine R, Rao S. Utility of flexible fiber optic bronchoscopy: Experience from a tertiary care teaching hospital. J NTR Univ Health Sci [serial online] 2013 [cited 2020 Apr 8];2:249-54. Available from: http://www.jdrntruhs.org/text.asp?2013/2/4/249/122159
| Introduction|| |
Flexible fibre optic bronchoscopy (FOB) is a procedure that is routinely performed in pulmonary medicine units of tertiary care hospitals. It is one of the important procedures utilized by physicians when the initial work-up of patients with suspected pulmonary pathologies remains inconclusive. FOB can help the bronchoscopist to visually evaluate the tracheobronchial tree and also to obtain samples like bronchoalveolar lavage (BAL) fluid, bronchial brushings, and bronchial biopsies. This can help the physician in arriving at a firm diagnosis and obviously influence the therapeutic decision-making. The spectrum of pulmonary conditions routinely encountered in a tropical country like India is different from that seen in the developed nations. This study was undertaken to identify the various clinical indications for which this procedure was done in a tertiary care teaching hospital in south India and to what extent it helped in confirming or refuting the same.
| Aims and Objectives|| |
- To identify the pre-bronchoscopy clinical diagnoses that were evaluated using FOB.
- Comparison of the suspected pre-bronchoscopy and confirmed post-bronchoscopy clinical diagnoses.
| Materials and Methods|| |
After taking a written permission from, the institutional ethics committee, a retrospective study was conducted at a 2050-bed tertiary care teaching hospital attached to a medical college in south India. The hospital provides healthcare services to surrounding urban, semi urban, and rural areas. The case records of 322 patients, admitted in the wards, who underwent FOB, between January 2009 and June 2012 were accessed from the medical records department of the hospital, and data was noted on a predesigned pro forma. The bronchoscopies were performed by senior chest physicians via the transnasal route using a Pentax video bronchoscope. The data pertaining to the study subjects such as age, sex, and suspected clinical diagnosis prior to bronchoscopy were recorded. In our centre, the suspected clinical diagnosis is arrived at after detailed discussion among a team of faculty members led by a senior physician.
"Suspected pulmonary tuberculosis" category consisted of patients who were diagnosed based on clinical presentation of chronic cough of more than 2 weeks and the chest roentgenogram revealing upper zone findings ranging from few infiltrates to consolidation and/or cavities. The sputum smears for acid-fast bacilli (AFB) were negative or patient could not produce sputum. "Suspected bacterial pneumonia" category included patients whom the clinician diagnosed as bacterial pneumonia, but the sputum microbiology reports either did not reveal the presence of bacterial pathogens or the patients did not produce sputum. "Lung malignancy" included patients whose clinical and radiological evaluation, particularly computed tomography of thorax, was suspicious of malignant lung mass. "Tracheo-esophageal fistula" as a category included patients with carcinoma esophagus, who were referred to rule out tracheo-esophageal fistula. "Interstitial lung disease" category comprised patients in whom clinical features, spirometry, and high resolution computed tomography (HRCT) of thorax were suggestive of the diagnosis. "Others" as a category had patients presenting with complaints of hemoptysis, but chest roentgenogram did not reveal any abnormality. Results of investigations done prior to bronchoscopy such as viral serology [including human immunodeficiency virus (HIV), hepatitis B, and hepatitis C virus], sputum smear (Gram's and Ziehl-Neelsen staining), and sputum bacterial culture were noted. The reports of routinely done post-bronchoscopy investigations such as BAL fluid bacterial culture, BAL fluid smear for AFB, and BAL fluid mycobacterial culture were also reviewed. Bronchial brushings and bronchial biopsy were not obtained routinely in all cases, but only in those where the bronchoscopist had decided to do so, based on his assessment of the lesions found on inspection of tracheobronchial tree. The post-bronchoscopy diagnoses based on laboratory reports of bronchoscopy generated samples were noted. The data was analyzed using SPSS 16.0 by descriptive statistics and has been presented in the form of tables.
| Results|| |
The mean age of the patients was 52.99 years (SD ± 15.1, range: 17-82). The baseline characteristics of the study population are shown in [Table 1].
The reasons why suspected pulmonary tuberculosis patients were referred for FOB were negative sputum smear for AFB (n = 60), negative induced-sputum smear for AFB (n = 48), and lack of sputum production even after hypertonic saline induction (n = 21). The chest radiographic findings of the subjects were suggestive of consolidation (n = 47, 14.6%), consolidation with pleural effusion (n = 17, 5.3%), non-homogenous infiltrates (n = 141, 43.8%), collapse (n = 14, 4.3%), cavity (n = 17, 5.3%), mass (n = 49, 15.2%), reticulo nodular infiltrates (n = 3, 0.9%), and no abnormality (n = 34, 10.5%). The patients whose chest roentgenogram did not reveal any abnormality belonged to pre-bronchoscopy categories of "tracheo-esophageal fistula" or "others."
Distribution of suspected pre bronchoscopy clinical diagnosis as per age, gender, and viral serological markers is shown in [Table 2]. Comparison of suspected clinical diagnosis with findings during bronchoscopy is shown in [Table 3]. Sixteen out of 142 (11.26%) post-bronchoscopy diagnosed cases had normal findings during FOB, whereas 98 out of 180 (54.44%) post-bronchoscopy undiagnosed cases had normal findings during FOB.
|Table 2: Distribution of Suspected Clinical Diagnosis as Per Age, Gender, and Viral Serological Markers (n=322)|
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|Table 3: Comparison of Suspected Clinical Diagnosis with Findings During Bronchoscopy|
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Comparison of pre-bronchoscopy suspected clinical diagnosis with a final post-bronchoscopy diagnosis is shown in [Table 4]. Distribution of final post bronchoscopy diagnosis as per age, gender, and viral serological markers is shown in [Table 5].
|Table 4: Comparison of Pre-Bronchoscopy Suspected Clinical Diagnosis with Post-Bronchoscopy Diagnosis (n=322)|
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|Table 5: Distribution of Final Diagnosis as Per Age, Gender and Viral Serological Markers (n=322)|
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| Discussion|| |
In the present study, pulmonary tuberculosis was the commonest suspected clinical diagnosis for which bronchoscopy was performed irrespective of age, gender, HIV status, or HBsAg (hepatitis B surface antigen) status. However, bacterial pneumonia was the overall commonest confirmed diagnosis after bronchoscopy in the study population. This highlights the fact that commonest diagnostic categories pre- and post-bronchoscopy were different. It also appears that the baseline characteristics of the subjects did not influence the decision-making process of the physicians in formulating the pre-bronchoscopy clinical diagnosis of pulmonary tuberculosis, as it was the commonest diagnosis across the baseline characteristics. However, post-bronchoscopy commonest confirmed diagnosis did vary according to the baseline characteristics [Table 5]. Thus, FOB did influence the physicians in reconsidering and revising their clinical diagnosis. In our study population, FOB helped in establishing the diagnosis in less than half of the cases. In various studies, the diagnostic yield of FOB ranged from 0% to 100% [Table 6]. ,,,,,,,,, The wide variation in the results observed in these studies could be due to the different indications for which FOB was performed in the various study populations.
|Table 6: Overall Diagnostic Yield of Fibre Optic Bronchoscopy in Various Studies|
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In a study conducted at Rural Medical College, Maharashtra, India, the authors reported that the commonest diagnosis post-bronchoscopy was bacterial pneumonia, i.e., in 32 out of 90 cases (35.55%).  A similar observation was reported in a study from a teaching hospital at Wardha in India, where community acquired pneumonia was confirmed in 18 out of 42 (42.9%) subjects who underwent bronchoscopy.  Our findings are consistent with the observations of these studies.
In the present study, the majority (24/28) of the confirmed pulmonary tuberculosis cases were rightly suspected by the clinicians prior to bronchoscopy. However, on the other hand, pulmonary tuberculosis was confirmed in only 18.6% (24/129) of the initially suspected cases. This is in contrast to a study done by Bachh et al., in Andhra Pradesh, India where the investigators found that bronchoscopy could confirm the diagnosis of pulmonary tuberculosis in 83.33% (50/60) of the suspected sputum smear negative cases.  In a retrospective study done at infectious disease unit of a hospital in United Kingdom, the diagnosis of pulmonary tuberculosis could be confirmed in 62 out of 180 patients (34%) with sputum-negative pulmonary tuberculosis.  Although this figure was higher than that in our study, it was much lower than the results obtained by Bachh et al.  This data suggests that, in our study, pulmonary tuberculosis was probably over diagnosed prior to bronchoscopy. This can be expected in a country like India where tuberculosis is a commonly encountered clinical condition and is considered in the differential diagnosis of various clinical presentations. In a study from a regional adult centre for tuberculosis in Auckland, New Zealand, the investigators reported that, out of 27 subjects from whom samples had been obtained after both hypertonic saline nebulisation and bronchoscopy, in one case bronchoscopy alone, in 13 cases hypertonic saline nebulisation alone, and in 13 both of the produced samples were positive for tuberculosis. Thus, 26 out of 27 cases samples obtained after hypertonic saline nebulisation succeeded in establishing the diagnosis.  In our centre, it is a routine practice to induce sputum by giving hypertonic saline nebulisation to patients who do not spontaneously produce sputum, and, only if that fails to yield a sample or the report is inconclusive is the patient subjected to FOB, if required. As is obvious from the previous study, such a practice reduces the number of patients of undiagnosed active pulmonary tuberculosis undergoing FOB. It also explains the fewer number of confirmed cases in our study.
In a study from Hong Kong in 1989, it was noted that, among 66% subjects who were diagnosed to be having pulmonary tuberculosis after bronchoscopy, the diagnosis was not initially suspected.  In our study, this figure was much lower at 14.2%. Two cases with pre-bronchoscopy diagnosis of lung malignancy and another two cases with a pre-bronchoscopy diagnosis of pneumonia were diagnosed as pulmonary tuberculosis following routine culturing of bronchoscopy samples in all cases. One of the reasons for lesser number of pulmonary tuberculosis cases being diagnosed in initially suspected non-tuberculosis diagnosis could be the advent of more sophisticated radiological imaging modalities. These imaging modalities are more widely available now, and it results in more precise pre-bronchoscopy diagnosis of various lung conditions such as lung masses. This may also explain our observation that 29 out of 30 intraluminal growths observed during bronchoscopy were noted in subjects with already suspected lung malignancy. Fewer of such cases are likely to have post-bronchoscopy diagnosis of pulmonary tuberculosis if radiological evaluation like computerized tomography of thorax is done prior to bronchoscopy. In a retrospective study conducted in 2004, at a pulmonary institute in Israel, comprising of 168 subjects with suspected lung malignancy, only one case (0.6%) was diagnosed as pulmonary tuberculosis following routine culturing of bronchoscopy samples in all cases.  In our study, the yield was only 2% in such cases. Hence, routine culturing of bronchoscopy samples in such settings needs to be assessed keeping cost benefit ratio in mind.
On comparing the top three suspected clinical diagnoses of pulmonary tuberculosis, lung malignancy, and bacterial pneumonia with the findings during bronchoscopy, it was observed that the highest proportion (51.9%) of normal bronchoscopy findings were noted in subjects with "suspected pulmonary tuberculosis" category. The "suspected lung malignancy" group had the least proportion of subjects with normal bronchoscopy findings and also the least undiagnosed cases post-bronchoscopy. Overall, post-bronchoscopy confirmed cases had lesser percentage of normal FOB findings than post-bronchoscopy undiagnosed cases. Thus, the chances of arriving at a confirmed clinical diagnosis were more if there were abnormal findings on bronchoscopy. The high percentage of normal bronchoscopic findings in "suspected pulmonary tuberculosis" category could be the result of cases being over-diagnosed in this category prior to bronchoscopy, and this is substantiated by the fact that only 18.6% of such cases were confirmed after bronchoscopy. "Others" category revealed presence of purulent secretions or distorted architecture in some cases although the chest roentgenogram was normal. This could be due to the fact that even findings such as scanty purulent secretions or slight architectural abnormalities, which were noted by the bronchoscopist were included in the analysis. Such minimal changes may not be visible on a chest roentgenogram.
In our study, half of the initially suspected cases of lung malignancy were confirmed to have malignancy after bronchoscopy, which was the highest percentage among the top three diagnostic categories. On the other hand, majority of the post-bronchoscopy confirmed cases of lung malignancy were rightly suspected by the referring physician prior to bronchoscopy. Out of all the categories, "lung malignancy" appears to have best correlation between pre- and post-bronchoscopy diagnosis [Table 5].
In a study done at an army medical centre in USA, out of 20 patients of carcinoma esophagus who underwent bronchoscopy, none had any evidence of tracheo-esophageal fistula. Moreover, in nine of these cases, no abnormality was observed during bronchoscopy.  Our findings are similar to this study, with no tracheo-esophageal fistula present in any of the cases.
The limitation of this study was that the exact methodology adopted by the referring physicians to arrive at the suspected clinical diagnosis was not studied. This can influence the final results obtained by bronchoscopy. The other limitation was that the data regarding the final diagnosis of patients, whose clinical condition remained undiagnosed following bronchoscopy, was not recorded. This probably could have shed light on reasons for failure of FOB to provide a diagnosis.
In conclusion, the bronchoscopy could provide a diagnosis in less than half of the cases. The commonest suspected pre-bronchoscopy clinical diagnosis was pulmonary tuberculosis, but the commonest confirmed post-bronchoscopy diagnosis was bacterial pneumonia. Lung malignancy category had the best correlation between suspected pre-bronchoscopy and confirmed post-bronchoscopy diagnoses. The routine mycobacterial culture of samples in suspected "lung malignancy" diagnostic category needs to be further evaluated.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]