Direct ultrasound localisation for pleural aspiration: translating evidence into action.

BACKGROUND: There is strong evidence that direct ultrasound localisation for pleural aspiration reduces complications, but this practice is not universal in Australia and New Zealand. AIMS: To describe the current utilisation and logistical barriers to the use of direct ultrasound localisation for pleural aspiration by respiratory physicians from Australia and New Zealand, and to determine the cost benefits of procuring equipment and training resources in chest ultrasound. METHODS: We surveyed all adult respiratory physician members of the Thoracic Society of Australia and New Zealand regarding their use of direct ultrasound localisation for pleural aspiration. We performed a cost-benefit analysis for acquiring bedside ultrasound equipment and estimated the capacity of available ultrasound training. RESULTS: One hundred and forty-six of 275 respiratory physicians responded (53% response). One-third (33.6%) of respondents do not undertake direct ultrasound localisation. Lack of training/expertise (44.6%) and lack of access to ultrasound equipment (41%) were the most frequently reported barriers to performing direct ultrasound localisation. An average delay of 2 or more days to obtain an ultrasound performed in radiology was reported in 42.7% of respondents. Decision-tree analysis demonstrated that clinician-performed direct ultrasound localisation for pleural aspiration is cost-beneficial, with recovery of initial capital expenditure within 6 months. Ultrasound training infrastructure is already available to up-skill all respiratory physicians within 2 years and is cost-neutral. CONCLUSION: Many respiratory physicians have not adopted direct ultrasound localisation for pleural aspiration because they lack equipment and expertise. However, purchase of ultrasound equipment is cost-beneficial, and there is already sufficient capacity to deliver accredited ultrasound training through existing services.

Clinical utility of sequential venous blood gas measurement in the assessment of ventilatory status during physiological stress.

BACKGROUND: Venous blood gases (VBG) are commonly utilised, particularly in the emergency setting, to assess and monitor patients at risk of ventilatory failure with limited evidence regarding their clinical utility in the assessment of ventilatory status over time. AIMS: This study aims to assess agreement between arterial and venous pH and partial pressure of carbon dioxide (pCO2) both before and after physiological stress, at each time point, and within the same subject between paired samples before and after bronchoscopy. METHODS: Prospective study of 30 patients undergoing flexible bronchoscopy under conscious sedation. Paired arterial and venous samples taken before and after bronchoscopy were analysed utilising descriptive statistics and bias plot (Bland-Altman) analysis to assess limits of agreement. RESULTS: Compared with baseline, post-bronchoscopy arterial blood gas and VBG showed reduced pH (-0.05 ± 0.05 and -0.04 ± 0.04 respectively) and increased arterial and venous pCO2 (5.9 ± 6.7 and 3.5 ± 5.5 mmHg respectively), the differences being statistically significant (P = 0.035). There was statistical agreement between arterial blood gas and VBG parameters; however, the limits of agreement were wide at rest and, for pCO2, widened further post-bronchoscopy. CONCLUSION: Sequential VBG provide an unpredictable means for assessing pCO2 in patients undergoing flexible bronchoscopy. Previously noted poor agreement between arterial and venous pCO2 worsens following physiological stress, with sequential VBG likely to underestimate changes in ventilatory status in patients with acute respiratory compromise, suggesting limited utility as a means for monitoring changes in ventilation.

Mediastinal staging of non-small-cell lung cancer among Australasian thoracic physicians: clinical practice and constraints on minimally invasive techniques.

BACKGROUND/AIM: We determined current practice among Australasian thoracic physicians in the mediastinal staging of non-small-cell lung cancer (NSCLC). We focused on the availability of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) and constraints to its use, as there has been no systematic analysis regarding the availability and uptake of this new technology among thoracic physicians. METHODS: Physician members of the Thoracic Society of Australia and New Zealand were emailed a survey seeking their current approach to three scenarios requiring mediastinal staging of NSCLC. Respondents were also asked for their preferred investigation for each scenario if any current constraints were removed. Relevant demographic information was sought. RESULTS: We received 164 responses from 512 Australasian physicians (34%). Without constraints, EBUS-TBNA was the preferred investigation for all three clinical scenarios, but only 33% of respondents had access to EBUS-TBNA. Constraints included lack of availability and lack of expertise. Reduced EBUS-TBNA access was associated with a number of clinician factors. CONCLUSIONS: Australasian thoracic physicians prefer EBUS-TBNA for the mediastinal staging of NSCLC, but access to EBUS-TBNA services is limited. We recommend targeted measures to improve access to EBUS-TBNA use and optimise mediastinal staging of NSCLC.

Radial probe endobronchial ultrasound for the diagnosis of peripheral lung cancer: systematic review and meta-analysis.

Improved diagnostic sensitivity of bronchsocopy for the investigation of peripheral pulmonary lesions (PPLs) with the use of radial probe endobroncial ultrasound (EBUS) has been reported, although diagnostic performance varies considerably. A systematic review of published literature evaluating radial probe EBUS accuracy was performed to determine point sensitivity and specificity, and to construct a summary receiver-operating characteristic curve. Sub-group analysis and linear regression was used to identify possible sources of study heterogeneity. 16 studies with 1,420 patients fulfilled inclusion criteria. Significant inter-study variation in EBUS method was noted. EBUS had point specificity of 1.00 (95% CI 0.99-1.00) and point sensitivity of 0.73 (95% CI 0.70-0.76) for the detection of lung cancer, with a positive likelihood ratio of 26.84 (12.60-57.20) and a negative likelihood ratio of 0.28 (0.23-0.36). Significant inter-study heterogeneity for sensitivity was observed, with prevalence of malignancy, lesion size and reference standard used being possible sources. EBUS is a safe and relatively accurate tool in the investigation of PPLs. Diagnostic sensitivity of EBUS may be influenced by the prevalence of malignancy in the patient cohort being examined and lesion size. Further methodologically rigorous studies on well-defined patient populations are required to evaluate the generalisability of our results.

Bronchoscopic evaluation of the mediastinum using endobronchial ultrasound: a description of the first 216 cases carried out at an Australian tertiary hospital.

BACKGROUND: Performance of linear probe endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for staging non-small-cell lung cancer has been extensively studied. Alternate indications for its use are less well characterised, and performance in other clinical settings may differ. METHODS: We examined a prospectively collected cohort comprising the first 215 patients undergoing EBUS-TBNA at our institution. Patients were analysed according to the clinical and radiological indication for referral. We also examined the effect of the procedural learning curve on diagnostic sensitivity. RESULTS: A total of 215 patients underwent 216 EBUS-TBNA procedures. EBUS-TBNA returned adequate tissue for cytopathological analysis in 202 of 216 procedures (94%). Overall sensitivity for detection of malignancy was 0.92 (95% confidence interval 0.86-0.96); however, this varied according to the primary indication for EBUS-TBNA. Diagnostic sensitivity was high among all sub-groups, but the negative predictive value varied depending on the clinical indication for the procedure. We estimate 104 invasive surgical procedures and 32 inpatient admissions were avoided by use of EBUS-TBNA. Significant improvement in diagnostic performance was seen after 20 procedures were completed, and diagnostic accuracy did not peak until after 50 procedures. CONCLUSIONS: EBUS-TBNA is able to confirm accurately histologically a large number of disease processes, both malignant and benign, in all clinical indications studied. The procedure is safe even when carried out by proceduralists with minimal prior experience. Diagnostic performance continues to improve beyond 50 cases carried out.

Cavitating lymph node metastasis demonstrated by endobronchial ultrasound.

Cavitation of primary non-small cell lung carcinoma (NSCLC) occurs in a small number of patients. We report a case of cavitation of lymph node metastases in NSCLC. CT chest showed central low attenuation of the subcarinal lymph node, suggestive of necrosis, and endobronchial ultrasound (EBUS) imaging demonstrated two cystic spaces within the lymph node. Transbronchial needle aspiration of the cystic space confirmed the presence of metastatic NSCLC. Cystic necrosis was only demonstrable by EBUS. The incidence of such findings is unknown, however with the increasing use of EBUS for evaluation of the mediastinum such images may be more commonly encountered in the future.

Endobronchial ultrasound staging of thyroid lesion in small cell lung carcinoma.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has proven its utility in the mediastinal staging of lung cancer. Its use in the evaluation of thyroid lesions has not previously been described. We report the safe and effective use of EBUS-TBNA to evaluate a thyroid lesion in a patient with suspected lung cancer at the time of diagnostic bronchoscopy. Use of this method in the evaluation of thyroid lesions may be considered in patients with coexistent mediastinal or hilar lesions, or for lesions not accessible to a percutaneous approach.

Incidence of bacteraemia following endobronchial ultrasound-guided transbronchial needle aspiration.

Few data exist concerning possible infectious complications associated with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The present prospective evaluation was undertaken in order to determine the incidence of bacteraemia and infectious complications associated with EBUS-TBNA. Consecutive patients undergoing EBUS-TBNA for evaluation of mediastinal or hilar lymph node lesions were studied. Venesection was performed within 60 s of TBNA for aerobic and anaerobic blood culture. Sterile saline washing of TBNA needles was also performed. Patients with positive blood cultures were reviewed immediately, and all patients underwent clinical review within 1 week of EBUS-TBNA. A total of 43 patients underwent EBUS-TBNA, with bacteraemia demonstrated in three (7%). All bacterial isolates were typical oropharyngeal commensal organisms. The TBNA needle washing culture was positive in 15 (35%) patients. None of the three bacteraemic patients had clinical features suggestive of infection, and no complications were seen among the cohort. The incidence of bacteraemia following EBUS-TBNA is comparable to that following routine flexible bronchoscopy. Performance of TBNA does not appear to measurably increase the risk of bacteraemia over that associated with insertion of the bronchoscope into the airway. Contamination of the TBNA needle with oropharyngeal commensal bacteria is common; however, clinically significant infection following EBUS-TBNA appears rare.

Advances in lung cancer diagnosis and staging: endobronchial ultrasound.

BACKGROUND: Endobronchial ultrasound (EBUS) is an accurate and relatively less invasive procedure for the diagnosis of lung lesions and mediastinal lymph node staging for lung cancer. We aimed to evaluate the clinical utility and safety of this new EBUS service established in our hospital. METHODS: Consecutive patients who underwent EBUS-transbronchial lung biopsy (EBUS-TBLB) for biopsy of peripheral pulmonary lesions or for transbronchial needle aspiration (TBNA) of mediastinal lymph node enlargement were included in this audit. Demographic and clinical data were obtained prospectively. Diagnostic yield from the results of EBUS was compared to other clinical information obtained. RESULTS: Thirty-eight patients underwent EBUS over a 10-month period. The yield from EBUS-TBLB was 62%. The average size of the lung lesions biopsied was 3.5 cm and 62% were located in the upper lobes. Malignancy was diagnosed in 14 cases and a benign aetiology in four. The yield from EBUS-TBNA was 88% and the average size of the lymph nodes was 2.3 cm. The lymph nodes were all located in the subcarinal station except for two that were in the lower paratracheal station. Malignancy was diagnosed in 10 cases on TBNA and 4 cases had benign pathology. There was one complication seen (small pneumothorax). CONCLUSION: EBUS is safe and an effective method for both, diagnosis of peripheral pulmonary lesions and staging for lung cancer.

The natural history of asthma from childhood to adulthood.

Medical Practitioners are often questioned regarding the prognosis of a child with asthma. We have performed a literature review of the natural history of childhood asthmatics. Factors which affect the natural history and prognosis of childhood asthma are discussed. Current evidence suggests that evolution of asthma severity is fairly predictable. Features of childhood asthma such as severity, duration, atopy, bronchial hyperresponsiveness and exposure to smoking can predict the course of asthma into adulthood. Most children with mild intermittent asthma will outgrow their asthma, or have mild episodic asthma. Early commencement of anti-inflammatory therapy, such as inhaled corticosteroids may prevent the progression of the disease. Most patients with mild asthma have good functional outcome and low healthcare utilisation.

Screening for lung cancer.

BACKGROUND: While population based screening for lung cancer has not been adopted by most countries, it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography are effective in reducing mortality from lung cancer. OBJECTIVES: To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality. SEARCH STRATEGY: Electronic databases (the Cochrane Central Register of Controlled Trials, MEDLINE, PREMEDLINE and EMBASE; 1966 to July 2000) ), bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials. SELECTION CRITERIA: Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest. DATA COLLECTION AND ANALYSIS: Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effects model, but for other outcomes the fixed effect model was used. MAIN RESULTS: Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT. REVIEWER'S CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Screening for lung cancer: a systematic review and meta-analysis of controlled trials.

BACKGROUND: Lung cancer is a substantial public health problem in western countries. Previous studies have examined different screening strategies for lung cancer but there have been no published systematic reviews. METHODS: A systematic review of controlled trials was conducted to determine whether screening for lung cancer using regular sputum examinations or chest radiography or computed tomography (CT) reduces lung cancer mortality. The primary outcome was lung cancer mortality; secondary outcomes were lung cancer survival and all cause mortality. RESULTS: One non-randomised controlled trial and six randomised controlled trials with a total of 245 610 subjects were included in the review. In all studies the control group received some type of screening. More frequent screening with chest radiography was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23). A non-statistically significant trend to reduced mortality from lung cancer was observed when screening with chest radiography and sputum cytological examination was compared with chest radiography alone (RR 0.88, 95% CI 0.74 to 1.03). Several of the included studies had potential methodological weaknesses. Controlled studies of spiral CT scanning have not been reported. CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytological examination. Frequent chest radiography might be harmful. Further methodologically rigorous trials are required before any new screening methods are introduced into clinical practice.

Screening for lung cancer.

BACKGROUND: The effectiveness of screening for lung cancer with chest radiography, sputum cytology or spiral CT has not been established. OBJECTIVES: To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality. SEARCH STRATEGY: Electronic databases, bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials. SELECTION CRITERIA: Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest. DATA COLLECTION AND ANALYSIS: Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effect model, but for other outcomes the fixed effect model was used. MAIN RESULTS: Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT. REVIEWER'S CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Recent advances in managing non-small-cell lung cancer: 1. Clinical aspects of diagnosis and staging.

Lung cancer is the leading cause of death from cancer in Australian adults. Over 90% of lung cancers are due to exposure to tobacco smoke. Female smokers are more susceptible to developing lung cancer than male smokers. The overall survival of non-small-cell lung cancer is 13%, having increased from 6% over the past 30 years. The development of new, unexplained respiratory or systemic symptoms in a heavy smoker or ex-smoker should raise the suspicion of lung cancer. Early detection and consideration of tumour resection for all operable tumours are the main strategies for improving the cure rate of non-small-cell lung cancer at present. Reducing the prevalence of smoking remains the best method for reducing lung cancer deaths.

Resolution of gas exchange abnormalities and intrapulmonary shunting following liver transplantation.

This prospective study evaluated pulmonary gas exchange in patients with severe liver disease, its relationship to intrapulmonary shunting, and its response to liver transplantation. Detailed clinical examinations, chest radiographs, and arterial blood gas estimations were performed on 74 consecutive patients before and after liver transplantation. Fifty percent of the 74 patients had a widened alveolar-arterial (A-a) oxygen gradient (> 15 mm Hg) and 45% a reduced PaCO2 (< 35 mm Hg). Twenty-two percent were hypoxemic (PaO2 < 80 mm Hg). Following transplantation mean PaO2 increased (pre-89 +/- 14 vs. post-94 +/- 8 mm Hg; P = .014) and A-a oxygen gradient decreased (pre-16 +/- 14 vs. post-8 +/- 9 mm Hg; P < .001), despite an increase in PaCO2 (pre-36 +/- 5 vs. post-39 +/- 4; P < .001). To examine this improvement in oxygen exchange further, a subgroup of 26 consecutive patients, with no obvious cardiorespiratory cause for abnormal gas exchange underwent, pre- and post-operative spirometry, measurement of carbon monoxide diffusion capacity (DLCO), intrapulmonary shunt estimations (100% oxygen technique), and echocardiography. In this subgroup, 23% were hypoxemic, 54% had a widened A-a oxygen gradient, and 85% had increased intrapulmonary shunting (> 5%) before transplantation. There was a significant correlation between the degree of pre-transplantation intrapulmonary shunting and A-a oxygen gradient (P < .01). Nineteen of the 22 patients with increased shunting improved following transplantation and improved A-a oxygen gradient correlated well with the reduction in shunting (P < .005). DLCO was reduced in 69% of these patients with a mean value of 73% of predicted. However, the post-transplantation mean DLCO did not increase despite the improvement in oxygen exchange. In conclusion, gas exchange abnormalities are common in patients with severe liver disease but these usually resolve post-transplantation. Intrapulmonary shunting is a major determinant of abnormal oxygen uptake in transplant candidates without evidence of cardiorespiratory disease. Finally, the mechanism for the reduced DLCO is unclear but appears different to that responsible for intrapulmonary shunting and abnormal oxygen exchange.