Extensive cross-contamination of specimens with Mycobacterium tuberculosis in a reference laboratory.
A striking increase in the numbers of cultures positive for Mycobacterium tuberculosis was noticed in a mycobacterial reference laboratory in Campinas, Sao Paulo State, Brazil, in May 1995. A contaminated bronchoscope was the suspected cause of the increase. All 91 M. tuberculosis isolates grown from samples from patients between 8 May and 18 July 1995 were characterized by spoligotyping and IS6110 fingerprinting. Sixty-one of the 91 isolates had identical spoligotype patterns, and the pattern was arbitrarily designated S36. The 61 specimens containing these isolates had been processed and cultured in a 21-day period ending on 1 June 1995, but only 1 sample was smear positive for acid-fast bacilli. The patient from whom this sample was obtained was considered to be the index case patient and had a 4+ smear-positive lymph node aspirate that had been sent to the laboratory on 10 May. Virtually all organisms with spoligotype S36 had the same IS6110 fingerprint pattern. Extensive review of the patients' charts and investigation of laboratory procedures revealed that cross-contamination of specimens had occurred. Because the same strain was grown from all types of specimens, the bronchoscope was ruled out as the outbreak source. The most likely source of contamination was a multiple-use reagent used for specimen processing. The organism was cultured from two of the solutions 3 weeks after mock contamination. This investigation strongly supports the idea that M. tuberculosis grown from smear-negative specimens should be analyzed by rapid and reliable strain differentiation techniques, such as spoligotyping, to help rule out laboratory contamination. (+info)
Placement of left-sided double-lumen endobronchial tubes: comparison of clinical and fibreoptic-guided placement.
We have compared a new intubation manoeuvre using a fibreoptic bronchoscope with conventional blind placement of a double-lumen tube. Thirty adult patients who presented for thoracoscopy requiring one-lung ventilation underwent endobronchial intubation with a double-lumen tube inserted either in the conventional blind way or using a fibreoptic bronchoscope. There were four misplacements of the double-lumen tube using the conventional method but none using the bronchoscope. In addition, the bronchoscope allowed more rapid intubation (mean 106 vs 347 s). The results suggest that the fibreoptic-guided method of inserting the double-lumen tube was a satisfactory alternative to the conventional one. (+info)
Peripheral airway findings in chronic obstructive pulmonary disease using an ultrathin bronchoscope.
The authors performed bronchoscopic examination using an ultrathin bronchoscope to determine the characteristics of the peripheral airways in chronic obstructive pulmonary disease (COPD). The study population comprised 13 healthy control subjects, 10 patients with chronic bronchitis without airflow limitation, and 20 patients with COPD. The COPD patients were divided clinically into 10 with chronic bronchitis and 10 with pulmonary emphysema. The peripheral airways were examined using an ultrathin bronchoscope. In chronic bronchitis, peripheral airways of the 11th or 12th generation showed a high frequency of obstruction and mucosal changes such as granulation. In pulmonary emphysema, the peripheral airways frequently showed a net-like appearance of the bronchial epithelium and obstruction at the 11th or 12th generation. Morphological changes of the small airways in chronic obstructive pulmonary disease can be detected by an ultrathin bronchoscope, and this method is likely to be useful for investigating the small airways in vivo. (+info)
Influence of airway-occluding instruments on airway pressure during jet ventilation for rigid bronchoscopy.
We measured changes in airway pressure (Paw) caused by microsurgical instruments introduced into a rigid bronchoscope during high frequency jet ventilation (HFJV). With approval of the institutional Ethics Committee, 10 adults undergoing elective tracheobronchial endoscopy and endosonography during general anaesthesia were investigated. Inflation of an endosonography probe balloon in the left main stem bronchus caused airway obstruction. Pressure measurements proximal and distal to the obstruction were compared after three degrees of obstruction (0%, 50% and 90%) and with two different driving pressure settings. Airway obstruction increased the mean (SD) peak inspiratory pressure (PIP) from 7.5 (2.6) to 9.5 (3.5) mm Hg for 2 atm (P = 0.0008) and from 9.7 (3.7) to 13.0 (5.1) mm Hg for 3 atm (P = 0.0001). Airway obstruction did not alter peripheral PIP (7.2 (4.1) to 7.1 (3.7) mm Hg for 2 atm and 8.8 (4.3) to 9.4 (5.2) mm for 3 atm), but resulted in an end-expiratory pressure (EEP) beyond the narrowing being significantly greater than in the unobstructed airway (2.5 (3.4) to 5.5 (3.7) mm Hg for 2 atm; P = 0.0005) and 3.2 (3.6) to 8.0 (4.3) mm for 3 atm; P < 0.0001). Severe airway narrowing increases inspiratory pressure proximal and expiratory pressure distal to the obstruction in relation to the applied driving pressure. Since the distal EEP never exceeded PIP, even near-total airway obstruction should not cause severe lung distension or barotrauma in subjects with normal lungs. (+info)
Flexible fiberoptic bronchoscopy. Anesthesia, technique and results.
During a period of three years, 256 diagnostic bronchoscopies were done with flexible fiberoptic bronchoscopes at a Veterans Administration hospital. In all of these procedures, topical cocaine hydrochloride anesthesia was used, and it proved satisfactory and free of any undesirable side effects. The peroral route using an endotracheal tube is preferred for flexible bronchofiberscopy. Fluoroscopic guidance is essential in examining peripheral lung lesions. A 70 percent positive yield was obtained for patients with peripheral carcinoma of the lung as contrasted to a 47 percent yield when the tissue specimens were obtained blindly. (+info)
Identification of a contaminating Mycobacterium tuberculosis strain with a transposition of an IS6110 insertion element resulting in an altered spoligotype.
Molecular fingerprinting with the IS6110 insertion sequence is useful for tracking transmission of Mycobacterium tuberculosis within a population or confirming specimen contamination in the laboratory or through instrumentation. Secondary typing with other molecular methods yields additional information as to the relatedness of strains with similar IS6110 fingerprints. Isolated, relatively rare, random events within the M. tuberculosis genome alter molecular fingerprinting patterns with any of the methods; therefore, strains which are different by two or more typing methods are usually not considered to be closely related. In this report, we describe two strains of M. tuberculosis, obtained from the same bronchoscope 2 days apart, that demonstrated unique molecular fingerprinting patterns by two different typing methods. They were closely linked through the bronchoscope by a traditional epidemiologic investigation. Genetic analysis of the two strains revealed that a single event, the transposition of an IS6110 insertion sequence in one of the strains, accounted for both the differences in the IS6110 pattern and the apparent deletion of a spacer in the spoligotype. This finding shows that a single event can change the molecular fingerprint of a strain in two different molecular typing systems, and thus, molecular typing cannot be the only means used to track transmission of this organism through a population. Traditional epidemiologic techniques are a necessary complement to molecular fingerprinting so that radical changes within the fingerprint pattern can be identified. (+info)
Ultrathin bronchoscopy as an adjunct to standard bronchoscopy in the diagnosis of peripheral lung lesions. A preliminary report.
BACKGROUND: The role of the standard bronchoscope as a method of diagnosis of peripheral lung lesions is limited. OBJECTIVES: To evaluate the role of the ultrathin bronchoscope as an adjunct to standard bronchoscopy in the diagnosis of peripheral lung lesions. METHODS: Seventeen consecutive patients with a peripheral lung lesion on chest radiography or chest CT. All patients underwent a bronchoscopic examination with a standard size bronchoscope, and if there was no evidence of endobronchial lesion, these patients were subsequently examined with an Olympus 3C40 ultrathin bronchoscope (external diameter of 3.6 mm). Under fluoroscopic guidance, cytological brushing samples were taken with the ultrathin bronchoscope followed by a reexamination with the standard bronchoscope which followed the same 'pathway' to the lesion established by the 3C40 ultrathin bronchoscope. Transbronchial biopsies (TBB) and cytological samples were taken with the standard bronchoscope. RESULTS: The size of the lesions ranged from 1.5 to 7.0 cm. A positive bronchoscopic diagnosis by TBB was obtained in 11 out of 17 patients (64.7%) and a diagnosis of atypical cells suspicious for malignancy noted in a further 3 patients. For lesions less than 3 cm in size, a positive diagnosis by TBB was achieved in 7 out of 10 of these cases. The lesion was directly visualized with the ultrathin bronchoscope in 4 cases. CONCLUSIONS: Ultrathin bronchoscopy appears to be a useful adjunct to standard bronchoscopy by providing an accurate pathway to the lesion in question. However, further studies with larger patient groups are warranted. (+info)
Endoluminal stent graft repair of aortobronchial fistulas.
OBJECTIVE: To describe our experience with endoluminal stent graft repair of aortobronchial fistulas. METHODS: We reviewed the records of patients treated with endoluminal stent grafting of aortobronchial fistulas at a private teaching hospital. All patients underwent the following diagnostic studies: computed tomography, angiography, bronchoscopy, and transesophageal echocardiography. With standard endovascular techniques, two different devices were implanted. RESULTS: Between March 1997 and October 2000, we treated four patients with postsurgical fistulas. The patients were diagnosed with hemoptysis between 3 and 23 years after aortic replacement grafting for thoracic aneurysms. Diagnostic studies varied in their ability to find the fistula. Transesophageal echocardiography most reliably demonstrated the fistula in the patients. All were successfully treated by exclusion with endoluminal stent grafting. The patients had no complications and no further episodes of hemoptysis. CONCLUSION: Endoluminal stent grafting of aortobronchial fistulas is feasible and may become the preferred method of management in patients at high risk. (+info)