Aspiration syndromes: 10 clinical pearls every physician should know.

Aspiration syndromes are clinically and pathologically classified into three sets of disorders: (i) large airway mechanical obstruction caused by foreign bodies; (ii) aspiration pneumonitis; and (iii) aspiration pneumonia. In this article, we discuss the common clinical presentations, risk factors, radiographic features and methods of management of these disorders. We highlight recent recommendations and controversies surrounding the prevention of aspiration pneumonia in the critically ill patient. Finally, we review ethical dilemmas surrounding feeding and aspiration risk concerns in debilitated and demented patients.

Accuracy of transbronchial needle aspiration for mediastinal staging of non-small cell lung cancer: a meta-analysis.

BACKGROUND: The reported accuracy of transbronchial needle aspiration (TBNA) for mediastinal staging in non-small cell lung cancer (NSCLC) varies widely. We performed a meta-analysis to estimate the accuracy of TBNA for mediastinal staging in NSCLC. METHODS: Medline, Embase, and the bibliographies of retrieved articles were searched for studies evaluating TBNA accuracy with no language restriction. Meta-analytical methods were used to construct summary receiver-operating characteristic curves and to pool sensitivity and specificity. RESULTS: Thirteen studies met inclusion criteria, including six studies that surgically confirmed all TBNA results and enrolled at least 10 patients with and without mediastinal metastasis (tier 1). Methodological quality varied but did not affect diagnostic accuracy. In tier 1 studies the median prevalence of mediastinal metastasis was 34%. Using a random effects model, the pooled sensitivity and specificity were 39% (95% CI 17 to 61) and 99% (95% CI 96 to 100), respectively. Compared with tier 1 studies, the median prevalence of mediastinal metastasis (81%; p = 0.002) and pooled sensitivity (78%; 95% CI 71 to 84; p = 0.009) were higher in non-tier 1 studies. Sensitivity analysis confirmed that the sensitivity of TBNA depends critically on the prevalence of mediastinal metastasis. The pooled major complication rate was 0.3% (95% CI 0.01 to 4). CONCLUSIONS: When properly performed, TBNA is highly specific for identifying mediastinal metastasis in patients with NSCLC, but sensitivity depends critically on the study methods and patient population. In populations with a lower prevalence of mediastinal metastasis, the sensitivity of TBNA is much lower than reported in recent lung cancer guidelines.

Health-related quality of life in patients with idiopathic pulmonary fibrosis: a systematic review.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) profoundly affects the quality of patients' lives. A systematic review was performed to evaluate critically the published literature and to examine what is known about health-related quality of life (HRQL) in patients with IPF. METHODS: The MEDLINE, EMBASE, Health and Psychosocial Instruments, and Cochrane Library databases were searched to 1 April 2004. Abstracts and bibliographies of published articles were scanned and contact was made with investigators. Included studies analysed HRQL (or quality of life) in at least 10 patients with IPF. Two reviewers independently selected studies, evaluated their quality according to predetermined criteria, and abstracted data on study design, patients' demographic and clinical characteristics, and quality of life outcome measures. RESULTS: Seven studies met the inclusion criteria. The studies enrolled 512 patients with IPF and used three different instruments to measure HRQL. All studies had important limitations in methodological quality; none measured longitudinal changes in HRQL over time. Patients reported substantially impaired HRQL, especially in domains that measured physical health and level of independence. Patients with IPF appear to have similar impairments in HRQL to those with chronic obstructive pulmonary disease. Measures of dyspnoea were moderately correlated with scores from domains that measured physical health (R2 = 0.03-0.66) and energy/fatigue/pep (R2 = 0.19-0.55), but measures of pulmonary function and gas exchange did not correlate as strongly with these and other domains. CONCLUSION: Studies of HRQL in patients with IPF suggest that, in addition to the obvious effect on physical health, general health, energy level, respiratory symptoms, and level of independence are also impaired. Variability in HRQL among patients is not fully explained by measures of dyspnoea or pulmonary function, suggesting that HRQL measures provide unique information. More research is needed to identify or design appropriate measurement instruments for patients with IPF and to examine changes in HRQL over time or in response to specific treatments.

Occupational inhalant exposure and respiratory disorders among never-smokers referred to a hospital pulmonary function laboratory.

BACKGROUND: Multiple reports have described associations between occupational inhalant exposure and lung disease. Previous occupational lung disease investigations have studied populations consisting of both smokers and nonsmokers. Smoking complicates interpretation of toxicant exposure-response relationships. The objective of this study was to determine whether, among never-smokers, occupational exposure to gases, dusts, or fumes is associated with a history of respiratory disorders and pulmonary function test defined obstructive lung disease. METHODS: We performed a retrospective analysis of 517 never-smoker patients who underwent pulmonary function testing in our clinical laboratory between 1986 and 1999. We calculated the relative risks of developing adverse respiratory health outcomes given a history of exposure to occupational inhalants. RESULTS: Compared with persons with a negative occupational exposure history, exposed persons had an increased risk of reporting a history of bronchitis [relative risk (RR), 1.59; 95% confidence interval (CI), 1.20-2.12], recurrent lung infections (RR, 2.09; 95% CI, 1.14-3.82), and bronchodilator use (RR, 1.61; 95% CI, 1.26-2.06). There was also a statistically significant association between a history of inhalant exposure and the finding of an obstructive ventilatory defect on pulmonary function testing (RR, 1.79; 95% CI, 1.12-2.85). A history of inhalant exposure was not associated with self-reported asthma (RR, 1.08; 95% CI, 0.83-1.41). The population attributable risk estimates for respiratory disorders due to inhalant exposure were: bronchitis, 23.6%; recurrent lung infection, 36.3%; bronchodilator use, 24.3%; and obstructive lung disease, 29.6%. CONCLUSIONS: Occupational inhalant exposure is a strong risk factor for lung disease in this population of never smokers. A significant burden of respiratory disease in this population may be attributable to occupational inhalant exposure.

Foreign body aspiration diagnosed by microscopy.

We report a rare case of foreign body aspiration diagnosed by microscopic analysis of a sample of the foreign body. A 50-year-old man presented with a 5-month history of 40 pound weight loss and a nonresolving right lower lobe pneumonia. Medical history, radiographic studies, direct visualization of the foreign body by flexible fiberoptic bronchoscopy, and gross examination of a sample of the foreign body retrieved by a forceps biopsy catheter failed to yield the diagnosis. Moderate bleeding associated with the bronchoscopic "biopsy" procedure contributed to a preliminary misdiagnosis of endobronchial tumor. Microscopic analysis of the "biopsy" specimen demonstrated vegetable matter. The patient underwent rigid bronchoscopy and a peanut was retrieved from the bronchus intermedius. He was maintained on antibiotics for an additional 8 weeks and had complete clinical and radiographic recovery. The epidemiology, presentation, and management strategies of foreign body aspiration in the adult are briefly reviewed.

Occupational and environmental causes of bronchogenic carcinoma.

Occupational and environmental carcinogens account for an important minority of cases of bronchogenic carcinoma. From a public health perspective, it is important to characterize occupational and environmental carcinogens and to define disease risk to reduce preventable lung cancer. From a clinician's perspective, it is important to distinguish individual cases of occupational lung cancer from nonoccupational cases, because cancer acquired from work may be compensable through worker's compensation claims and litigation. Important carcinogens include asbestos, radon daughters, diesel exhaust, and metals. Epidemiologic investigations identify excess cases of lung cancer in populations exposed to carcinogens. Experimental animal and ex vivo human research provide complementary information supporting causal relationships between exposure and carcinogenesis. Clinical challenges include proving that a given case of lung cancer is due to an occupational exposure. Research challenges include determining safe exposure thresholds. Only a small percentage of all chemicals used in industry have been extensively analyzed for their carcinogenic potential. Scientific and regulatory information about pulmonary occupational and environmental health and safety is available from several important agencies and organizations, including the Occupational Safety and Health Administration, the National Institute for Occupational Safety and Health, the International Agency for Research on Cancer, the American Lung Association, and the Environmental Protection Agency.

Improved quality of life among patients completing a pulmonary rehabilitation program: one center's early experience.

INTRODUCTION: The conclusion of previous investigations that pulmonary rehabilitation (PR) is an effective intervention for the management of chronic lung disease may not be generalizable to PR programs with limited experience delivering this complex, interdisciplinary service. OBJECTIVE: Determine whether PR is effective for the first group of patients treated in a newly formed interdisciplinary PR program. METHODS: We conducted a longitudinal analysis of changes in health-related quality of life and 6-minute walk test for the first group of patients completing our newly formed 8-week outpatient PR program. We studied 6 men, age 65-77 years, with stable severe chronic obstructive pulmonary disease. Patients completed the Chronic Respiratory Disease Questionnaire immediately before and 1 year after participation in our PR program. RESULTS: Four patients completed the PR 6-minute walk test both before and after the program. We found improvement in all Chronic Respiratory Disease Questionnaire domains at follow-up (mean +/- SD before and after): dyspnea 1.67 +/- 0.82 vs 4.92 +/- 0.49; emotional function 2.33 +/- 0.82 vs 5.50 +/- 0.55; fatigue 2.00 +/- 0.63 vs 5.00 +/- 0.63; feeling of mastery over disease 1.83 +/- 0.41 vs 5.83 +/- 1.17. The interval improvements in all health-related quality of life domains were statistically significant (p < 0.02 for all comparisons). There was a trend toward improvement in exercise tolerance: 231 +/- 213 ft before PR vs 353 +/- 66 ft at the 1-year follow-up (p = 0.2). CONCLUSIONS: PR can result in sustained improvement in the quality of life of patients with severe chronic obstructive pulmonary disease, even when this complex, interdisciplinary service is delivered by a newly formed and inexperienced PR program.

Accuracy of positron emission tomography for diagnosis of pulmonary nodules and mass lesions: a meta-analysis.

CONTEXT: Focal pulmonary lesions are commonly encountered in clinical practice, and positron emission tomography (PET) with the glucose analog 18-fluorodeoxyglucose (FDG) may be an accurate test for identifying malignant lesions. OBJECTIVE: To estimate the diagnostic accuracy of FDG-PET for malignant focal pulmonary lesions. DATA SOURCES: Studies published between January 1966 and September 2000 in the MEDLINE and CANCERLIT databases; reference lists of identified studies; abstracts from recent conference proceedings; and direct contact with investigators. STUDY SELECTION: Studies that examined FDG-PET or FDG with a modified gamma camera in coincidence mode for diagnosis of focal pulmonary lesions; enrolled at least 10 participants with pulmonary nodules or masses, including at least 5 participants with malignant lesions; and presented sufficient data to permit calculation of sensitivity and specificity were included in the analysis. DATA EXTRACTION: Two reviewers independently assessed study quality and abstracted data regarding prevalence of malignancy and sensitivity and specificity of the imaging test. Disagreements were resolved by discussion. DATA SYNTHESIS: We used a meta-analytic method to construct summary receiver operating characteristic curves. Forty studies met inclusion criteria. Study methodological quality was fair. Sample sizes were small and blinding was often incomplete. For 1474 focal pulmonary lesions of any size, the maximum joint sensitivity and specificity (the upper left point on the receiver operating characteristic curve at which sensitivity and specificity are equal) of FDG-PET was 91.2% (95% confidence interval, 89.1%-92.9%). In current practice, FDG-PET operates at a point on the summary receiver operating characteristic curve that corresponds approximately to a sensitivity and specificity of 96.8% and 77.8%, respectively. There was no difference in diagnostic accuracy for pulmonary nodules compared with lesions of any size (P =.43), for semiquantitative methods of image interpretation compared with qualitative methods (P =.52), or for FDG-PET compared with FDG imaging with a modified gamma camera in coincidence mode (P =.19). CONCLUSIONS: Positron emission tomography with 18-fluorodeoxyglucose is an accurate noninvasive imaging test for diagnosis of pulmonary nodules and larger mass lesions, although few data exist for nodules smaller than 1 cm in diameter. In current practice, FDG-PET has high sensitivity and intermediate specificity for malignancy.

Benzocaine-associated methemoglobinemia following bronchoscopy in a healthy research participant.

Benzocaine (ethyl aminobenzoate) is a local anesthetic commonly used to achieve topical anesthesia of the skin and mucous membranes prior to endoscopic procedures. Methemoglobinemia, a condition in which hemoglobin cannot bind and deliver oxygen normally, has been associated with benzocaine use in various patient populations. This is the first report of benzocaine-associated methemoglobinemia occurring in a healthy research participant. The research participant developed a methemoglobin level of 27% and marked cyanosis. No adverse sequelae other than cyanosis were identified. This report extends the population in which benzocaine-associated methemoglobinemia has been described. Additionally, this report supports the observation that methemoglobin levels approaching 30% may be tolerated in otherwise healthy individuals, producing few clinically important effects. Finally, this case also indicates that, in obtaining informed consent for a procedure in which benzocaine will be administered, patients and research participants should be specifically informed of the risk of benzocaine-induced methemoglobinemia. This information is especially important in those settings in which the manufacturer-recommended dose of benzocaine may either intentionally or inadvertently be exceeded.

Massive esophageal variceal hemorrhage triggered by complicated endotracheal intubation.

Esophageal variceal hemorrhage is frequently a catastrophic event. The specific events that trigger variceal rupture are not well understood. Acute elevations in systemic blood pressure and increased splanchnic blood flow, however, may lead to increased intravariceal pressure followed by variceal rupture and hemorrhage. This report describes a strong temporal association between complicated endotracheal intubation and abrupt onset of life-threatening variceal hemorrhage. A 52-year-old man with a history of portal hypertension was intubated emergently for airway protection because of respiratory insufficiency due to sepsis. Intubation was complicated by initial inadvertent esophageal intubation and by a peak mean arterial blood pressure of 155 mmHg. At the conclusion of the procedure, the patient sustained large volume hematemesis due to esophageal variceal rupture. This case suggests a risk of triggering variceal hemorrhage as a result of intubation-induced increase in blood pressure. A number of agents, including fentanyl, have been shown to be effective in attenuating the cardiovascular response to intubation. This case report provides strong evidence in support of administering fentanyl, or a suitable alternative adjunctive medication, before intubation of patients with documented portal hypertension and a history of esophageal variceal hemorrhage.

Clinical and chest radiographic findings among persons with sputum culture positive for Mycobacterium gordonae: a review of 19 cases.

STUDY OBJECTIVES: To describe the clinical and radiographic findings associated with growth of Mycobacterium gordonae in cultured sputum and to determine the proportion of cases that fulfill criteria for nontuberculous mycobacterial pulmonary disease as established by the American Thoracic Society. DESIGN: A retrospective review of charts and radiographs of all patients from whom M gordonae was isolated from sputum cultures between November 1996 and June 1998. SETTING: University-affiliated Veterans Affairs hospital. PATIENTS: Nineteen patients were identified with sputum culture positive for M gordonae. All patients had a chest radiograph within 1 month of sputum culture. RESULTS: Sixteen patients (84%) had suppressed local and/or general immunity. Sixteen patients (84%) had respiratory symptoms, weight loss, fever, or night sweats as an indication for chest radiography. Seventeen patients (89%) had abnormal chest radiographs; however, no typical radiographic pattern was observed. No patient met diagnostic criteria for nontuberculous mycobacterial pulmonary disease as delineated by the American Thoracic Society. All patients with abnormal chest radiographs and/or respiratory symptoms ultimately had alternative explanations for their pulmonary disease. CONCLUSIONS: There is a broad spectrum of chest radiographic findings among persons with sputum culture positive for M gordonae, arguing against the presence of a characteristic chest radiograph in this patient population. M gordonae is usually a nonpathogenic colonizing organism, even among persons with local or general immune suppression and abnormal chest radiograph findings.

Ten asthma pearls every primary care physician should know.

Asthma is often easily identified and effectively treated. However, presenting symptoms are variable, and many cases of asthma may not be obvious or typical. Since asthma affects about 5% of the US population, primary care physicians should be prepared to identify and manage both atypical and classic types. Atypical symptoms include disturbed sleep, chest tightness, and persistent cough without audible wheezing. Occupational factors should be suspected in all cases of adult-onset asthma. The patient's history and results of simple pulmonary function tests are useful in diagnosing, staging, and managing asthma. A beta 2 agonist delivered by metered-dose inhaler (e.g., albuterol) should provide prompt relief of most exacerbations. Inhaled corticosteroid therapy delivered via a spacer helps prevent exacerbations and has an important role in long-term control of moderate and severe asthma. If symptoms do not improve with the use of standard asthma medications, alternative diagnoses should be considered.