Diagnostic value of protected BAL in diagnosing pulmonary infections in immunocompromised patients.

STUDY OBJECTIVES: To assess the diagnostic utility of protected BAL (P-BAL) in respiratory infections in immunocompromised patients and to examine whether P-BAL alone could substitute the combined use of protected specimen brush (PSB) and BAL in such patients. PATIENTS AND STUDY DESIGN: Thirty-seven immunocompromised patients who underwent PSB, P-BAL, and BAL simultaneously for the diagnosis or exclusion of bacterial or nonbacterial opportunistic respiratory infections were studied prospectively. The P-BAL was performed through the inner catheter of a telescoping plugged catheter with 60 mL of saline solution. MAIN RESULTS: Thirteen (35%) cases of bacterial pneumonia were diagnosed. PSB obtained seven true-positive (TP) results, P-BAL obtained nine, and BAL obtained eight TP. Results of the three techniques were positive and concordant in 6 of the 13 cases. PSB remained free of contamination from oropharyngeal flora in all cases, P-BAL was contaminated twice, and BAL was contaminated in four cases. Opportunistic respiratory infections were diagnosed in 19 patients. P-BAL results were identical to those with BAL in all cases: 18 TP and 1 false-negative. The average volume of P-BAL fluid retrieved was 19 mL, sufficient for all microbiologic and cytologic processings. P-BAL was more time-consuming than both PSB and BAL procedures and was technically more complex. CONCLUSION: P-BAL alone can substitute the combined use of both PSB and BAL in immunocompromised patients and attains a higher sensitivity than PSB in diagnosing bacterial pneumonia. The combined strategy continues to be a good choice, but due to the high incidence of bacterial pneumonia in these patients, a highly efficient diagnostic procedure is required not only for nonbacterial opportunistic respiratory infections but also for bacterial pneumonia.

Risk factors for infection by Pseudomonas aeruginosa in patients with ventilator-associated pneumonia.

OBJECTIVE: to investigate the epidemiology of infection by Pseudomonas aeruginosa in patients with ventilator-associated pneumonia (VAP). DESIGN: prospective clinical study. SETTING: a medical-surgical ICU in a university hospital. PATIENTS: we followed-up 568 mechanically ventilated patients and 83 episodes of VAP with etiologic diagnosis in 72 patients were retained for analysis. RESULTS: Ps. aeruginosa was isolated in 22 (26.5%) episodes in 18 patients. Of these episodes 7 were directly responsible for death. Using logistic regression analysis, the risk of VAP due to Ps. aeruginosa was increased in patients with chronic obstructive pulmonary disease (relative risk (RR) = 29.9, 95% confidence interval (CI) = 4.86-184.53), a mechanical ventilation period longer than 8 days (RR = 8.1, 95% CI = 1.01-65.40) and prior use of antibiotics (RR = 5.5, 95% CI = 0.88-35.01). CONCLUSIONS: patients with VAP and these factors have a greater risk of infection by Ps. aeruginosa and empirical therapy for these episodes should include anti-pseudomonal activity until etiologic diagnosis is established.

In-use evaluation of Perasafe compared with Cidex in fibreoptic bronchoscope disinfection.

The mycobactericidal activity of Perasafe (0.26% peracetic acid) was compared with that of Cidex (2% alkaline glutaraldehyde) by an in-use test. Fibreoptic bronchoscopes were artificially contaminated with Mycobacterium tuberculosis or Mycobacterium avium-intracellulare in sputum and, after manual pre-cleaning with a neutral soap, 10 and 20 min disinfection periods were tested. Perasafe was as effective as Cidex, thus requiring a 10 min disinfection period against M. tuberculosis and 20 min against M. avium-intracellulare. The results demonstrate that Perasafe is an effective disinfectant for use in reprocessing fibreoptic bronchoscopes.

[Fiberoptic bronchoscope disinfection with glutaraldehyde phenolate in 1:8 solution]. / Desinfección del broncofibroscopio con glutaraldehído fenolato a la dilución 1:8.

We evaluated the efficacy of phenolated glutaraldehyde in a 1:8 solution for the disinfection of bronchofibroscopes that were highly contaminated with Serratia marcescens and Pseudomonas aeruginosa. An Olympus BF-P10 bronchofibroscope was contaminated with artificial samples containing one of the aforementioned microorganisms in concentrations nearing 10(8) colony forming units per milliliter (cfu/ml). The instruments were then washed with soap and water and submerged in a 1:8 solution of phenolated glutaraldehyde. Samples were taken for culturing after contamination, after washing, and after 10, 15 and 30 min in the disinfectant solution. The level of cfu/ml in the cultures was measured and the definition of failure-to-disinfect was a finding of > or = 1 cfu/ml after each experimental procedure. Twenty procedures, 10 for each microorganism, were carried out. Washing of the bronchofibroscope afforded significant elimination of microorganisms and no colony growth was observed in cultures after 10 min submersion in phenolated glutaraldehyde. We conclude that immersion in a 1:8 solution of phenolated glutaraldehyde after careful washing is a valid way to disinfect bronchofibroscopes that are highly contaminated with S. marcescens and P. aeruginosa.

[Protected bronchoalveolar lavage: a new endoscopic method in the diagnosis of bacterial pneumonia]. / Lavado broncoalveolar protegido: nuevo método endoscópico en el diagnóstico de las neumonías bacterianas.

BACKGROUND: The identification of causative microoganisms in severe pneumonias is a usually difficult problem. Protected brushing (PB) has a good specificity but a limited sensitivity. Conventional bronchoalveolar lavage (BAL-C) has an excellent sensitivity but a doubtful specificity. The investigation of a new technique such as the protected bronchoalveolar lavage (BAL-P) appears as logical, as it should combine the advantages of PB and BAL-C without their drawbacks. METHODS: In 15 patients without bacterial or fungal infections and in 23 with bacterial or fungal pneumonia, quantitative cultures were carried out in the samples obtained with PB, BAL-P and BAL-C. PB and BAL-C were performed with the usual technique. BAL-P was performed through the internal catheter of a telescoped double catheter with reabsorbable distal cap within the fibroscope channel. 40 ml of saline were instillated for the lavage. RESULTS: With BAL-P sensitivity was 95% and specificity 89%. These were, respectively, 55% and 94% with PB, and 95% and 42% with BAL-C. The technique of BAL-P was more complex an longer than that of PB. CONCLUSIONS: If these results are confirmed in further studies, BAL-P might become a method of choice for the bacterial pneumonias where now PB is indicated. However, in patients with hypersecretion or when bronchoscopy should be rapidly carried out, PB is technically more feasible.

[Bacterial pneumonia in the acquired immunodeficiency syndrome]. / Neumonía bacteriana en el síndrome de inmunodeficiencia adquirida.

Sixty five patients with AIDS and clinical and/or radiological evidence of pulmonary infection underwent 78 bronchofibroscopies (BF) with protected brushing and bronchoalveolar washing-out. Out of the 78 BF, bacterial infection was diagnosed in 30 cases and associated opportunistic infection in 12 cases. The 18 cases of exclusively bacterial infection accounted for 23% of the total and most of them were due by H. influenzae and pneumococcus. Just in one patient, the thoracic radiography showed a localized infiltration. Given the high incidence of bacterial infections observed, along with the relevance of myxoid infections (opportunistic and pyogenic bacteria) and the low specificity of the thoracic radiography, bronchoalveolar washing-out and protected brushing in the same BF is a recommended practice.

[Impossibility of intubation due to angioedema secondary to an angiotensin-converting enzyme inhibitor]. / Imposibilidad de intubación por angioedema secundario a IECA.

Angioedema secondary to treatment of one year's duration with angiotensin converting enzyme inhibitor (ACEI) (lisinopril) in a 56-year-old man scheduled for elective cardiac surgery led unexpectedly to impossible intubation. Surgical access (tracheostomy) was required when airway control was threatened. We review the clinical course, etiology and treatment of angioedema secondary to ACEI therapy. This is a life threatening complication which, though rare, is becoming increasingly frequent with increased use of such drugs.

[Experimental study of bronchofibroscope disinfection]. / Estudio experimental de la desinfección del broncofibroscopio.

BACKGROUND: Fibrobronchoscopes (FB) require high level disinfection following each procedure to prevent possible infectious complications. The aim of the present study was to evaluate three methods of disinfection of the FB: a) aspiration with a solution of iodine povidone (IP); b) immersion in fenolate glutaraldehyde (FG) diluted at 1:16, and c) aspiration of IP solution followed by immersion in FG. Cleaning of the FB with soap and water was also studied. METHODS: The FB was contaminated with artificial samples (sterilized respiratory secretions mixed with a suspension of a microorganism at a concentration of 10(8)-10(9) UFC/ml) and was later washed with soap and water and disinfected with one of the 3 above mentioned methods. Samples were taken following contamination, cleaning, the aspiration with IP and at 5, 10, 15, 20 and 30 minutes in FG. The c/u/ml were counted. Disinfection was considered as a failure with > or = 1 c/u/ml at the end of each experience. This test was performed 97 times: 37 with Mycobacterium tuberculosis, 17 with Serratia marcescens, 17 with Pseudomonas aeruginosa, 13 with Staphylococcus aureus, and 13 with Candida albicans. RESULTS: Cleaning with soap and water eliminated a mean of 99.9% of the microorganisms. IP failed to disinfect all the 5 microorganisms while FG and the association of IP and FG failed against S. marcescens and P. aeruginosa. The time of immersion in FG required for complete disinfection range from 5 to 20 minutes although in most cases only 5 to 10 minutes were needed. CONCLUSIONS: The meticulous cleaning of the FB is essential for correct disinfection. Iodine povidone does not guarantee high level disinfection of the device while fenolate glutaraldehyde and iodine povidone plus fenolate glutaraldehyde may fail versus S. marcescens and P. aeruginosa.

Cytology of postbronchoscopically collected sputum samples and its diagnostic value.

The usefulness of the cytology of postbronchoscopically collected sputum (PBS) samples in the diagnosis of neoplastic lung disease has been studied in 113 cases. The overall diagnostic yield of fiberoptic bronchoscopy (FB) alone was 77%, 87% in 77 central tumors and 58% in 36 peripheral ones. With the addition of PBS, the positive results increased to 91% in the 113 cases (p less than 0.01), to 94% n central tumors (p greater than 0.05) and to 83% in peripheral lesions (p less than 0.02). In 15 cases PBS offered the unique positive results. 73 cases with histological confirmation showed a good cytohistological correlation in 82%. Our report suggests that PBS is a useful technique in the diagnosis of lung cancer. Its systematic use does not seem to be justified in central tumors, but it is of great value in peripheral tumors when fluoroscopic control is not available.

Tracheobronchopathia osteochondroplastica.

6 cases of tracheobronchopathia osteochondroplastica are discussed. Diagnoses were established ante mortem. Endoscopic examination was performed in 3 patients because of hematic expectoration, in the other 3 cases the induction was given by chronic bronchorhea, slow-resolving pneumonia and suspected neoplasia, respectively. Calcification and cartilaginous areas were restricted to a small portion of the tracheobronchial tree in 1 of the cases; in 3 cases the disease affected the trachea and both main bronchi, whereas it was found markedly spread throughout the trachea in the last 2 patients. Tracheal tomography and bronchoscopic examination are considered the methods of choice for an ante mortem diagnosis of this disease.

Diagnosis and staging of bronchogenic carcinoma by transtracheal and transbronchial needle aspiration.

Transbronchial needle aspiration (TBNA) has been used in diagnosis and staging of bronchogenic carcinoma. However, its true effectiveness seems uncertain and some models of needles are expensive. The aim of this study was to procure new experiences on this method. TBNA was performed in 194 patients with bronchogenic carcinomas. Two models of cheap, re-usable, cytological needles were used. In diagnostic application, TBNA was positive in 34 of 39 (87%) central tumors and in 31 of 45 (69%) peripheral nodules or masses. In 19 patients, TBNA was the only positive sample. In staging application, TBNA was positive in 41 of the 90 cases (46%) in which the spread of the tumor compressed the wall of the airway. When the trachea or bronchus was endoscopically normal at the site of the puncture, TBNA was only positive in 3 of 20 cases (15%). These results suggest that TBNA is effective as a diagnostic tool. However, it appears to be less effective in staging, where the attainment of a good yield with TBNA probably demands a positive computed tomography and the use of a histological needle.

Risk factors for Staphylococcus aureus nosocomial pneumonia in critically ill patients.

Staphylococcus aureus nosocomial pneumonia has become an important infection not only because of an apparently increasing incidence but also because of its high mortality rate. A total of 50 episodes of nosocomial pneumonia in critically ill patients in which etiologic diagnosis was well established were prospectively followed in a medical-surgical intensive care unit (ICU). S. aureus was isolated in a total of 13 episodes. In the univariate analysis the variables significantly associated with S. aureus nosocomial pneumonia were below 25 yr of age, coma, nonuse of corticosteroids, and antecedent trauma. A step-forward logistic regression analysis defined only coma as significantly influencing the risk of developing S. aureus nosocomial pneumonia. We suggest that antimicrobial drugs active against S. aureus must be included in the initial empirical antimicrobial regimen for treating nosocomial pneumonia in patients with coma. The identification of factors influencing the etiology and the possibility of earlier effective antimicrobial treatment may represent a further step in the control of nosocomial pneumonia in critically ill patients by improving its prognosis.

Nosocomial pneumonia in critically ill comatose patients: need for a differential therapeutic approach.

The purpose of this prospective clinical study was to determine the incidence, bacteriology and outcome of lower respiratory tract infections developed among 208 consecutive, critically ill comatose patients, hospitalized in a university hospital, medical-surgical intensive care unit, over a three year period. Nosocomial pneumonia developed in 53 (25%) patients after a mean of 8.1 days (range 3-31 days). Furthermore, there were five superinfections, raising the mean incidence to 28%. One patient developed secondary bacteraemia, and another two had septic shock. Fifteen (28%) patients from the pneumonia group died, and six of these deaths were considered to be directly related to nosocomial pneumonia. Identification of the causative agent, using the protected specimen brush technique, was possible in 42 episodes; in 10 (24%) of these cases more than one microorganism was isolated. Gram-positive cocci represented 53% of isolates, and Staphylococcus aureus accounted for 78% of all Gram-positive cocci, being the most frequent microorganism in this population. In conclusion, nosocomial pneumonia is a common complication of critically ill comatose patients. Its characteristic aetiological spectrum in this population should affect antibiotic prescription. Consequently, we suggest including antimicrobial drugs which are active against S. aureus in the empirical regimen until aetiological diagnosis is established.

Lung cancer in patients with tracheostomy due to cancer of the larynx.

During 3 years, a prospective study was undertaken to investigate the frequency of lung cancer (LC) in patients with a tracheostomy after laryngectomy for neoplasm of the larynx (LxC). The protocol required a thorax radiography (RX) and a bronchofiberscopy (BF) every 6 months in each patient. Of the 286 cases studied, a diagnosis of LC was made in 36 (12.5%). In 6 of these 36 patients, there were no symptoms suggestive of LC and the RX was normal, and the diagnosis of LC was made only by systematic BF. A surgical treatment of LC was possible in only 7 cases. These results suggest that there is a high frequency of LC in patients with tracheostomy due to LxC, and also that it would be better to restrict the follow-up with systematic BF to those patients suitable for thoracotomy.

Bronchoscopy guided by high-resolution computed tomography for the diagnosis of pulmonary infections in patients with hematologic malignancies and normal plain chest X-ray.

BACKGROUND AND OBJECTIVES: High-resolution computed tomography (HRCT) of the chest is able to demonstrate the presence of pulmonary infiltrates in febrile neutropenic patients with normal chest X-rays. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is a safe procedure for the etiological diagnosis of pulmonary infiltrates in oncohematologic patients. The objective of this study was to determine the diagnostic yield and subsequent therapeutic changes of a protected BAL (p-BAL) guided by HRCT in febrile oncohematologic patients unresponsive to broad-spectrum antibiotics with a normal chest X-ray. DESIGN AND METHODS: Twenty-two episodes from 20 oncohematologic patients were included: group A, 9 episodes (8 patients) with no respiratory symptoms and group B, 13 episodes (12 patients) with signs or symptoms of pulmonary infection. HRCT and p-BAL were performed in all episodes within the first 24 hours. RESULTS: HRCT showed abnormalities in all 22 episodes (bilateral abnormalities in 14 of the 22 episodes [64%]) and the most frequent pattern was ground-glass infiltrate (7 out of 22 episodes). An infectious agent was isolated in 12 of the 22 episodes, 5 in group A and 7 in group B with a diagnostic yield of 54%. Antimicrobial therapy was modified in 12 of the 22 episodes (54%): 5 in group A and 7 in group B. In 6 episodes, treatment was changed according to HRCT results and in the remaining 6 due to positive microbiologic results. Modifications in empirical therapy were associated with a favorable response in 44% episodes of group A and in 31% of group B. INTERPRETATION AND CONCLUSIONS: Oncohematologic patients with fever of unknown origin unresponsive to empirical antibiotics and with a normal chest X-ray can be candidates to undergo a HRCT. This subgroup of high-risk patients can benefit from a combined strategy consisting of BAL guided by a previous HRCT.

Risk factors of treatment failure in community acquired pneumonia: implications for disease outcome.

BACKGROUND: An inadequate response to initial empirical treatment of community acquired pneumonia (CAP) represents a challenge for clinicians and requires early identification and intervention. A study was undertaken to quantify the incidence of failure of empirical treatment in CAP, to identify risk factors for treatment failure, and to determine the implications of treatment failure on the outcome. METHODS: A prospective multicentre cohort study was performed in 1424 hospitalised patients from 15 hospitals. Early treatment failure (<72 hours), late treatment failure, and in-hospital mortality were recorded. RESULTS: Treatment failure occurred in 215 patients (15.1%): 134 early failure (62.3%) and 81 late failure (37.7%). The causes were infectious in 86 patients (40%), non-infectious in 34 (15.8%), and undetermined in 95. The independent risk factors associated with treatment failure in a stepwise logistic regression analysis were liver disease, pneumonia risk class, leucopenia, multilobar CAP, pleural effusion, and radiological signs of cavitation. Independent factors associated with a lower risk of treatment failure were influenza vaccination, initial treatment with fluoroquinolones, and chronic obstructive pulmonary disease (COPD). Mortality was significantly higher in patients with treatment failure (25% v 2%). Failure of empirical treatment increased the mortality of CAP 11-fold after adjustment for risk class. CONCLUSIONS: Although these findings need to be confirmed by randomised studies, they suggest possible interventions to decrease mortality due to CAP.