Getting the bugs out of BAL

Sleep and neuromuscular disease: frequency of sleep-disordered breathing in a neuromuscular disease clinic population

We investigated 60 adult and pediatric patients (33 male, 27 female) with various neuromuscular disorders for sleep-disordered breathing in a clinic population at a local altitude of 1,500 m. Measurements included a questionnaire concerning symptoms of sleep and daytime function, a disability index, and pulmonary function tests. We used an EdenTrace monitor for 1 night to evaluate breathing during sleep and calculated mean and minimum oxygen saturation (SpO2), total apneas, hypopneas, and respiratory disturbance index (RDI). We had validated the EdenTrace II monitor prior to the study. The majority of the patients had symptoms of daytime dysfunction. The frequency of sleep-disordered breathing in this population was much higher (42% with RDI > 15) than frequencies indicated in recent population-based surveys. Spirometry revealed no positional effect in this population. Statistical analysis comparing RDI with disability index, pulmonary function tests, age, sex, body mass index, and Epworth Sleepiness Scales identified no strong correlates that could be used as predictors of sleep-disordered breathing in this population. Sleep studies using ambulatory equipment such as the EdenTrace II are an easy and effective means of identifying sleep-disordered breathing in patients with neuromuscular disorders and, given the high frequency of sleep-disordered breathing in our sample, should be performed on most patients with neuromuscular disorders if sleep-disordered breathing is to be identified early.

Value of bronchoalveolar lavage and gastric lavage in the diagnosis of pulmonary tuberculosis in children

OBJECTIVE

The aim of our study was to find out if bronchoalveolar lavage (BAL) would be better than gastric lavage for the isolation of Mycobacterium tuberculosis from pediatric patients with suspected pulmonary tuberculosis.

DESIGN

50 children with suspected pulmonary tuberculosis at a mean age of 5.1 years (range 7 months to 12 years) were studied. Early morning gastric lavage was collected. Flexible bronchoscopy and bronchoalveolar lavage was performed under local anaesthesia after obtaining informed consent from the parents. The BAL fluid and gastric lavage specimens were subjected to smear examination for acid-fast bacilli (AFB) and culture for mycobacteria using established methods.

RESULTS

Of the 50 cases, M. tuberculosis was grown in 6 BAL samples (12%) and 16 gastric lavage samples (32%) making a total of 17 culture proven cases (34%). Out of the 6 BAL positive cases, gastric lavage was also positive in 5 cases.

CONCLUSION

We conclude that gastric lavage is better than BAL for bacteriologic confirmation of pulmonary tuberculosis in children. The overall bacteriologic yield combining both procedures was 34% while gastric lavage alone was positive in 32% of the cases.

Quantitative culture of bronchoalveolar lavage fluid for the diagnosis of bacterial pneumonia

PURPOSE

A prospective study to determine the usefulness of quantitative bacterial cultures of fluid obtained via fiberoptic bronchoscopy and bronchoalveolar lavage as an aid in the diagnosis of bacterial pneumonia.

PATIENTS AND METHODS

All patients undergoing fiberoptic bronchoscopy with bronchoalveolar lavage during a 6 1/2-month period. Presence of pneumonia was determined using clinical, radiographic, laboratory, and histologic data. Quantitative bacterial cultures of bronchoalveolar lavage fluid were determined using a 1-microL culture loop.

RESULTS

Quantitative bacterial cultures of bronchoalveolar lavage (BAL) fluid were sensitive and specific predictors of bacterial pneumonia. Using 10(3) colony-forming units (cfu)/mL as the threshold value for a positive culture, we determined the sensitivity and specificity to be 90% and 97%, respectively. The data were also analyzed for the subgroups of patients who were intubated or were receiving antibiotics. The sensitivity and specificity were 78% and 96% for the group of patients receiving antibiotics and 100% and 82% for the group of patients intubated for more than 24 hours at the time of BAL. Values for the area under the receiver operating characteristic curve for the 3 groups were 0.94, 0.88, and 0.96, respectively.

CONCLUSIONS

Quantitative bacterial cultures of BAL fluid are sensitive and specific in the diagnosis of bacterial pneumonia. The use of antibiotics at the time of BAL reduces the sensitivity of the test, and prolonged intubation reduces the specificity of the test.

Changing trends in infective endocarditis

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Rhodotorula rubra contamination in fiberoptic bronchoscopy

Rhodotorula rubra was recovered in 18 bronchoscopic specimens from 15 patients from May to November 1987. One hundred and twenty-one bronchoscopies were performed during that period by two bronchoscopists (W. W.; R.D.) at Letterman Army Medical Center in San Francisco. Isolation of R rubra occurred in 11 bronchoalveolar lavage (BAL) specimens, four bronchial washes, and three transbronchial biopsies. Clinical infection was not present in any of these patients, although five were immunocompromised hosts. After a stepwise infection control review of the laboratory, the bronchoscopy suite, bronchoscopists, and the fiberoptic bronchoscope failed to recover the organism, a systematic evaluation of the cleaning procedure was undertaken. We discovered that replacement of the suction valve and the rubber biopsy valve on the biopsy channel immediately after cleaning allowed moisture to accumulate in these areas. Removal of both the suction valve and biopsy valve during periods of nonuse resulted in adequate drying of the biopsy channel and eradication of contamination from December 1987 to May 1990 (350 bronchoscopies). Epidemiologic and infection control surveillance is critical for bronchoscopy, especially when possible pathogens are recovered by BAL in the immunocompromised patient.