Guideline registries and libraries: a mixed-methods approach identified issues to be addressed with content.

OBJECTIVE: To establish what GIN guideline community members see as the desirable features of a guidelines library and registry of guidelines in development STUDY DESIGN AND SETTING: An explorative mixed-methods study was undertaken, including scoping activity and semi-structured interviews with guideline developers and endorsers from nine member organizations of the Guidelines International Network. RESULTS: A small number of desirable features of a guideline library were identified: comprehensiveness; single source of information to avoid searching multiple sites; inclusion of related materials; being up to date; searchability and ease of use. No existing library of guidelines was considered to have all of these features. A number of issues arose out of the desire to have a comprehensive library of guidelines, including inclusion of 'high quality guidelines' and limiting the scope to include only national guidelines. For registries of guidelines in development, the data set should be limited to avoid placing undue burden on those entering information. CONCLUSION: Our findings identify ongoing issues for the guideline community, including the tension between comprehensiveness and ease of use, which can result in limited uptake, reporting of guideline quality and the need for clarity on the purpose of any library or registry.

The utility of transbronchial needle aspiration in the staging of bronchogenic carcinoma.

We conducted a prospective multi-institutional clinical study involving community hospitals and academic medical centers to more carefully define the value of computerized tomography (CT) of the chest with transbronchial needle aspiration (TBNA) in the staging of bronchogenic carcinoma (CA), and to assess the predictors of a positive aspirate. Of 360 individuals determined to have bronchogenic carcinoma, 50 of 81 (62%) with small cell carcinoma (SCC) and 135 of 279 (48%) with non-small cell carcinoma (NSCC) had positive aspirates (p = 0.034). TBNA precluded additional thoracic surgery in a total of 104 of 360 (29%) patients and was exclusively diagnostic of carcinoma in 65 of 360 (18%) cases. Right-sided tumors were more likely to have a positive mediastinal TBNA (p = 0.002 to 0. 01) as were histologic (67 of 118 [57%]) rather than cytology aspirates (228 of 532 [41%]) (p < 0.001). Sensitivity was > 57% in lymph nodes (LN) >/= 10 mm, and among LN of equivalent size, right paratracheal and subcarinal sites were most likely to establish malignancy. Preoperative CT is a valuable adjunct in the staging of CA by TBNA. Increasing LN size, right-sided tumors, right paratracheal and subcarinal locations, use of a histology needle, and the presence of SCC are the best predictors of a positive aspirate.

Epidemiology and clinical consequences of drug-resistant tuberculosis in a Guatemalan hospital.

STUDY OBJECTIVE: To determine the epidemiology and clinical consequences of drug-resistant TB in Guatemala. DESIGN: A prospective study conducted for 12 months. SETTING: A thoracic referral hospital in western Guatemala. PATIENTS: Three hundred and seventy-six patients with confirmed TB. RESULTS: Of 376 confirmed cases, 335 (89%) were culture-positive. Tests of drug sensitivities to four first-line antituberculous drugs were performed in 172 (51%) of the culture-positive cases. Fifty-one patients (30%) were resistant to at least one antimicrobial agent, and 26 (15%) were resistant to at least two drugs. In a multivariate model of clinically available patient characteristics, only cavitary disease (odds ratio=2.1; 95% confidence interval, 1.1-6.6) and a history of taking anti-TB medication for >2 weeks (OR=3.0; 95% CI, 1.5-10.3) were independent predictors of resistance to two or more anti-TB agents. Resistance to two or more anti-TB drugs was the single independent predictor of treatment failure (OR=6.4; 95% CI, 2.3-17.8). Twenty-four of 172 patients (14%) who denied having received prior anti-TB therapy were infected with resistant organisms, suggesting ongoing transmission of drug-resistant strains. Although 84% (69 of 82 cases) of patients with fully susceptible organisms and 89% (17 of 19 cases) with singly resistant organisms were cured, only 45% of patients (10 of 22 cases) infected with organisms resistant to two or more agents were successfully treated. CONCLUSIONS: At this sentinel site for complicated TB, a substantial subset of cases who are infected with drug-resistant bacteria cannot be easily identified or treated.

The staging of lung cancer by bronchoscopic transbronchial needle aspiration.

The development of flexible transbronchial needles for hilar and mediastinal aspiration had made possible noninvasive staging at the time of the initial diagnostic bronchoscopic examination. Combining the specificity of TBNA with the sensitivity of thoracic CT scanning greatly enhances the utility of this procedure. A bronchoscopically oriented staging system that utilizes the complementary advantages of both of these techniques is outlined. The staging of bronchogenic carcinoma by TBNA is a safe and cost-effective technique that can be routinely utilized to stage lung cancer. Ultimately, its value will depend upon whether the initial encouraging reports of its use can be reproduced by bronchoscopists in practice.

Respiratory failure and cor pulmonale associated with tracheal mucoid accumulation from a SCOOP transtracheal oxygen catheter.

Transtracheal oxygen (TTO) delivery for patients with chronic hypoxemia has been used increasingly since its introduction in 1982. Most complications have been relatively minor and usually occur in conjunction with catheter placement. This report describes two patients with long-term catheter use who developed increasing respiratory failure and cor pulmonale, at least in part, due to a large tracheal mucus plug.

Bronchoscopic and roentgenographic correlates of a positive transbronchial needle aspiration in the staging of lung cancer.

A study was conducted to determine the bronchoscopic and chest roentgenographic findings associated with a positive TBNA. One hundred fifty-seven of 465 patients who were diagnosed for the first time as having carcinoma of the lung had a positive aspirate. Bronchoscopic findings associated with a positive TBNA of N2 nodes were carinal widening and endobronchial disease, especially of the right upper lobe. Mediastinal adenopathy noted on chest roentgenograms and subcarinal nodes on CAT scans were associated with a positive aspirate as well. In 34 of 465 patients, TBNA was the only means of establishing the diagnosis of pulmonary malignancy. A useful, simple and safe procedure, TBNA can be used to stage the mediastinum in patients with lung cancer and is most likely to be positive with endobronchial and nodal disease. It can also facilitate therapeutic decision-making in patients whose surgical candidacy is marginal.

Transbronchial needle aspiration in clinical practice. A five-year experience.

We conducted a five-year review of our use of TBNA during bronchoscopy in our clinical practice. Out of 1,630 bronchoscopic procedures, 633 patients (39 percent) had TBNA performed as part of the initial examination. Mediastinal nodes were sampled in 86 percent of the patients who had TBNA performed, and 127 (23 percent) of 547 of these aspirates were positive. Other areas of mucosal abnormality of the tracheobronchial tree were also sampled by TBNA under direct vision and showed malignant cells in 44 (25 percent) of 176 aspirates. Of 363 patients first diagnosed as having carcinoma of the lung who had TBNA of N2 nodes, 41 (59 percent) of 70 with small-cell tumors were positive, as were 83 (28 percent) of 293 with non-small-cell malignant neoplasms. Comparison of cytologic results obtained by TBNA with histologic material in 109 cases showed an excellent correlation. In 31 cases (4 percent of all TBNA), the aspirate provided the sole means of establishing the diagnosis of cancer. Two patients were thought to have false-positive aspirates. No complications of therapeutic significance were encountered. We believe that TBNA is a safe and effective way to assess mediastinal lymphatic involvement in the staging of lung cancer and that TBNA can be safely performed as part of the initial bronchoscopic examination in patients suspected of having malignant neoplasms of the chest.

Transbronchial needle aspiration in clinical practice.

Transbronchial needle aspiration has recently been adapted for use with the flexible bronchoscope. We studied 108 patients, who had a total of 110 aspirations performed, and diagnosed thoracic cancer in 70 cases. Transbronchial needle aspiration revealed malignant disease in 32 (46%) of these 70 patients. In 12 (17%) patients with cancer this technique provided the sole cytological or histological confirmation of the diagnosis. It gave a positive result in an additional 20 (29%) cases in which the diagnosis was also proved by conventional procedures, and it provided important staging information in these patients. In 20% of patients with cancer transbronchial needle aspiration precluded the need for further diagnostic surgery. There were no complications in this series. This is a safe, useful, and economical technique that can be used in diagnosing and staging patients with carcinoma of the lung.

The persistence and significance of elevated alanine aminotransferase levels in blood donors.

The level of alanine aminotransferase (ALT) in blood donors has been related to the frequency of posttransfusion hepatitis in recipients. Sixty-seven donors with elevated ALT levels were evaluated to define the duration and significance of the elevation. The ALT level remained elevated in 41 donors (61%) for a mean interval of 9 months. The ALT level was greater than the aspartate aminotransferase in all of the donors. Alcohol intake did not correlate with ALT level. Donors with persistently elevated ALT levels had a significantly higher mean percent ideal body weight (128 +/- 3.9) than donors whose ALT level became normal (116 +/- 3.1). Nine donors with elevated ALT levels for at least 6 months had needle biopsies of the liver. Seven had prominent fatty vacuolization of hepatocytes without evidence of alcoholic hepatitis. One biopsy demonstrated chronic persistent hepatitis. No other cause for the elevated ALT levels could be identified. An overweight male donor with an isolated ALT elevation may need no further investigation unless clinical evaluation suggests a source of liver injury.

A cytochemical and ultrastructural study of acute myelomonocytic leukemia exhibiting the pseudo-Chediak-Higashi anomaly of leukemia and "splinter-type" Auer rods.

An unusual case of acute myelomonocytic leukemia (AMML) in an 81-year-old man is described. Ultrastructural examination revealed the presence of distinct Auer bodies, which commonly are found in acute promyelocytic leukemia (APL). The Auer bodies had a splinterlike appearance with a distinct tubular substructure. The morphologic appearance of the leukemic cells coupled with the results of cytochemical staining reactions (alpha-naphthyl AS-D chloroacetate esterase, alpha-naphthyl butyrate esterase, Sudan black B, and periodic acid-Schiff reaction) identified this leukemia as myelomonocytic in origin. APL-like Auer rods in AMML now can be included in the spectrum of morphologic forms commonly seen in myelogenous leukemia and lends support to the hypothesis of an aberrant stem cell. In addition to the APL-like Auer rods, the leukemic blasts contained giant pink-staining granules on Wright's stain, some of which had a tubular substructure similar to the Auer rods under the electron microscope. The presence of these megagranules is a morphologic aberration termed "the pseudo-Chediak-Higashi anomaly of acute leukemia," and now has been described for the first time in AMML at the ultrastructural level.

A cellulose acetate electrophoretic procedure evaluated for quantitation of high-density lipoprotein cholesterol.

We evaluated the performance of a commercially available cellulose acetate electrophoretic method for quantitating high-density lipoprotein cholesterol (I) in serum by comparing it to a method involving precipitation with dextran sulfate-500/Mg2+. In both methods, enzymic reagents are used for cholesterol measurement. For electrophoretic measurement of I the mean intramembrane CV ws 4.1% (at 220 to 360 mg/L) and the intermembrane CV ranged from 12.2 to 21.0% (at 220 to 880 mg/L). Interassay precision was significantly better for the precipitation method (CV = 3.9% at 390 mg/L). The electrophoretic procedure demonstrated significant measurement bias, both at high and low I concentrations. However, low-density lipoprotein cholesterol, measured electrophoretically correlated well with its calculated concentrations obtained by the precipitation method. Measurement of I by this electrophoretic procedure did not achieve the accuracy and reproducibility that have been demonstrated for precipitation methods and that are necessary for reliable clinical interpretation of results for I.

Pulmonary arteriovenous fistula. Preoperative evaluation with a Swan-Ganz catheter.

A balloon-tipped catheter was used in the preoperative assessment of a patient with a solitary pulmonary arteriovenous fistula and coexistent chronic obstructive pulmonary disease and ischemic heart disease. Studies before and two months following surgical excision of the fistula showed that the increase in arterial oxygenation (49 mm Hg vs 77 mm Hg) and the reduction in the fraction of the shunted cardiac output (37% vs 6%) closely approximated the predicted preoperative estimates.

The pulmonary response to a bacteremic challenge.

The pulmonary response to a bacteremic challenge was studied in a mouse model. The distribution of intravenously injected radiotracer-labeled Proteus mirabilis and Staphylococcus aureus in the lungs, liver, spleen, kidney, and blood was examined at 0, 5 30, 60, and 240 min. Pulmonary killing of these organisms was studied at 0, 30, and 240 min; 0.8 plus or minus 0.1 per cent of the P. mirabilis and 1.5 plus or minus 0.2 per cent of the S. aureus remained within the lungs after 4 hours. Although only 2.2 plus or minus 0.2 per cent of the P. mirabilis organisms were alive, 33.8 plus or minus 8.8 per cent of the staphylococci remained viable after this period. Light and electron micographs verified that polymorphonuclear leukocytes phagocytized these bacteria. The defense mechanisms of the lung against bloodborne and airborne bacterial infection are functionally, as well as morphologically, distinct.