Pulmonary infiltrates in immunocompromised patients. Diagnostic value of telescoping plugged catheter and bronchoalveolar lavage.

The usefulness of telescoping plugged catheter (TPC) together with bronchoalveolar lavage (BAL) in the same bronchoscopic act in the diagnosis of pulmonary infiltrates was studied in 113 fiberoptic bronchoscopic examinations performed on 96 immunocompromised patients. The TPC cultures detected pulmonary bacterial infections in 25 (22 percent) cases but showed a high frequency of false positive results (12 microorganisms, 27 percent). Bronchoalveolar lavage had an overall diagnostic yield of 49 percent (53 of 113 cases). Combining TPC and BAL diagnostic values, 78 of 113 pulmonary infiltrates (69 percent) were diagnosed. The results obtained by both techniques allowed us to modify the treatment in 35 (31 percent) cases. Combined, TPC and BAL show a good diagnostic yield in immunocompromised patients with pulmonary infiltrates. Both techniques should be performed as the first approach in the evaluation of these patients, and be done in the same bronchoscopic procedure.

Diagnostic value of nonfluoroscopic percutaneous lung needle aspiration in patients with pneumonia.

In forty-one patients (mean [+/- SD] age 51 +/- 19 years; range, 11 to 88 years; seven female and 34 male) with clinical signs and symptoms of pneumonia, we performed a nonfluoroscopic percutaneous lung needle (22 gauges) aspiration (PLNA) to investigate the diagnostic yield of this technique. All the patients were receiving antibiotics at the time of the study, and PLNA was performed either because of a lack of response to empiric antibiotic treatment or because of the severity of the pneumonia or the underlying condition of the patient. Eight patients were mechanically ventilated (MV) due to acute respiratory failure. The PLNA was performed at bedside and without fluoroscopic guidance. Twenty-two microorganisms were identified by means of stains and/or cultures of PLNA samples. Sensitivity of PLNA was 43 percent (18/41). We detected three false-positive cultures probably due to contamination from the skin area punctured. In the eight MV patients studied, the sensitivity of PLNA was 37.5 percent, and the microbiologic findings turned out to be crucial for the outcome of the patients. Pneumothorax developed in three patients (7 percent) after PLNA. None of these three patients developed a pleural infection but two of them required thoracostomy drainage. None of the MV patients presented complications. Our results showed that nonfluoroscopic PLNA is a technique with moderately good sensitivity and with a low rate of false-positive cultures (8 percent) to diagnose pulmonary infections in patients with unresponsiveness to empiric antibiotic treatment or with severe pneumonia. Further evaluation of its diagnostic value and complications in MV patients is needed, although our preliminary results suggest that PLNA can be an alternative technique to other methods for diagnosing pulmonary infections in patients receiving artificial ventilatory support.

Diagnostic value of telescoping plugged catheters in HIV-infected patients with pulmonary infiltrates.

To assess the diagnostic value of telescoping plugged catheters (TPC) in human immunodeficiency virus (HIV)-infected patients with pulmonary infiltrates (PI), we performed a prospective clinical study in 71 episodes of fever and PI in 66 HIV-infected patients (five patients had two different episodes of fever and PI). A control group of 12 HIV-infected patients with fever and normal chest roentgenogram was also studied. In all patients and prior to antibiotic treatment (except in mechanically ventilated patients), a TPC using quantitative cultures (cutoff point established at 10(3) CFU/ml) and a bronchoalveolar lavage (BAL) sampling were performed via fiberoptic bronchoscope. The overall incidence of bacterial pneumonia in the study group was 21 percent. The TPC cultures resulted in a microbiologic diagnosis of bacterial pneumonia in eight patients (11 percent) from the study group and in one patient (8 percent) from the control group. The TPC sensitivity in diagnosing bacterial infections was 53 percent and specificity was 76 percent. Negative predictive value was 85 percent and positive predictive value was 38 percent. By means of BAL, 35 episodes from the study group and two from the control group were diagnosed as nonbacterial or mycobacterial pulmonary infections. Considering TPC and BAL together, diagnosis was performed in 42 cases of PI (59 percent). Twenty percent (17/83) of HIV-infected patients suffered from bacterial colonization of their lower airways (a TPC culture greater than or equal to 10(3) CFU/ml without clinical evidence of bacterial infection). We conclude that the combined use of TPC and BAL may be useful in HIV-infected patients with PI, since this combined use allows the proper diagnosis of bacterial and nonbacterial infections, thereby increasing the overall diagnostic accuracy. To distinguish bacterial colonization from pulmonary infection in HIV-infected patients with PI, the cutoff point of quantitative cultures of TPC may be 10(4) CFU/ml.

[Prospective study of community-acquired pneumonias seen in a general hospital. Diagnostic errors]. / Estudio prospectivo de las neumonías extrahospitalarias atendidas en un hospital general. Error diagnóstico.

BACKGROUND: The patients with community acquired pneumonias seen in an emergency service of a basic general hospital during one year were evaluated to assess their etiological, clinical and radiological features, and also to investigate the initial and final diagnosis of the disease, its evolution and the parameters associated with each microbiological type. METHODS: A medical team investigated daily the clinical records. For etiologic diagnosis, blood cultures, serological studies, urine counterimmunoelectrophoresis (CIE) and, in individualized patients, pleural fluid culture, bronchoaspirate and bronchoalveolar lavage were performed. The discordance between the initial clinical and radiological diagnosis and the microbiological results, and also the initial and final diagnostic errors were analyzed. RESULTS: 311 cases of pneumonia (150 adults and 161 children) were diagnosed. 95 (30%) had microbiological confirmation. Streptococcus pneumoniae was the most commonly isolated organism. Serologic studies were the diagnostic method with the highest yield. Complications developed in 28% of the patients and the mortality rate was 2%. There was a relationship between mortality and a high respiratory rate on admission. The initial-final diagnostic discrepancy was 43% in atypical pneumonias and 40% in bacterial pneumonias. CONCLUSIONS: Clinical parameters permitting the differentiation between atypical and bacterial pneumonia were not found. The initial diagnostic error was 12%, consisting of false positives in all instances, and the final diagnostic error included 15% false positives and 10% false negatives. Underlying diseases have a influence on the evolution of pneumonia. The mean respiratory rate on admission should be measured as a prognostic indicator. In the present study, urine CIE was a poorly sensitive method.

[Sepsis caused by Candida parapsilosis. Joint and lung involvement in 2 patients with acute leukemia]. / Sepsis por Candida parapsilosis. Afección articular y pulmonar en dos pacientes con leucemia aguda.

Sepsis due to Candida parapsilosis with involvement of the joints and the lungs, respectively, is reported in two patients with acute leukemia. The first patient had ankle arthritis 72 days after an allogenic bone marrow transplant for acute lymphoblastic leukemia. The second patient had pneumonia with cavitation during pancytopenia after chemotherapy for acute monocytic leukemia. In both cases, C. parapsilosis sepsis responded to therapy with amphotericin B, associated with miconazole in the first patient and with 5-fluorocytosine in the second one. The rarity of septic foci during C. parapsilosis fungemia and the good outcome of both patients are emphasized. This good result was probably due to early antifungal therapy and the relatively rapid recovery of granulocytopenia.

Opportunistic pulmonary infections in solid organ transplant recipients.

BACKGROUND: Opportunistic pulmonary infections (OPI) represent common life-threatening complications after solid organ transplantation. Our objective was to describe pulmonary infections caused by opportunistic pathogens in solid-organ transplant patients. METHODS: We analyzed all adult solid organ recipients (liver, heart, kidney, and pancreas) between July 2003 and June 2010, reporting all episodes of pulmonary opportunistic infection. RESULTS: During the study period, 1656 solid organ transplants were performed and 188 opportunistic infections were diagnosed in 163 patients (incidence 10%). In 40 cases, the site of infection was the lung (21%) with 57.5% occurring between the first and sixth month posttransplantation. The most frequently isolated microorganism was Aspergillus spp (n = 25, 63%), followed by Pneumocystis jirovecii (n = 6 cs, 15%). Twenty-five patients with an opportunistic pulmonary infections died during the follow-up including, 16 related to the infection (40%). The causative organism responsible for the highest mortality was Aspergillus spp (n = 12; 48%). Twenty-one patients with an opportunistic nonrespiratory infection died, five of them related to it (4%). Opportunistic pulmonary infection was associated with an increased mortality rate (P < .001). There was a trend toward a higher mortality among patients who developed OPI during the first 6 months after transplantation. CONCLUSIONS: Opportunistic pulmonary infections after solid organ transplantation are not infrequent. The period of risk for developing this infectious complications goes beyond the first 6 months posttransplantation. Mortality due to these infections was high in comparison to that of opportunistic nonrespiratory infections. It is important to keep a high index of suspicion for infectious complications during all posttransplant periods, as this is the first step toward a rapid diagnosis and adequate treatment.

Bacteriological study of surgical knives: is the use of two blades necessary?

Scalpel blades used in 115 operations were studied bacteriologically. In each case the knife used for skin incision was discarded immediately after the incision and a fresh knife was used to complete the operation. The scalpel blades were cultured in enriched thioglycolate and incubated at 37 degrees C. Readings were taken at 24 and 48 h. From positive cultures, colonies were isolated directly in solid media, and the germ was identified using routine tests. Results showed that there was no bacteriological evidence to justify the use of different blades for skin incision and deep dissection.

Bacterial colonization as a potential source of nosocomial respiratory infections in two types of spirometer.

The potential risk of spirometers in the transmission of respiratory infections has not been yet established. We performed a prospective cross-sectional study to determine the rate of colonization of a water-sealed spirometer and a pneumotachograph, and the potential risk of cross-transmission of microorganisms to patients using each of these devices. Fifty four patients (aged 51 +/- 18 (mean +/- SD) yrs) were included in the study. All of them had undergone forced spirometry with bronchodilator response by means of the water-sealed spirometer (n = 36) or the pneumotachograph (n = 18). None had a clinically apparent respiratory infection at the time of the study. Routine hygiene measures for respiratory equipment were performed before the study protocol. Samples for microbiological cultures of different parts both of the water-sealed spirometer (proximal and distal tubing, bell and water-bell) and pneumotachograph (proximal and distal tubing) were taken daily before and after the usual series of lung function tests during a 5 day period. Pharyngeal swab cultures were obtained before spirometry and 7 days later in each subject. Thirty six out of a total of 40 (90%) culture samples from the water-sealed spirometer showed microbial growth compared to 4 out of 30 (13%) samples obtained from the pneumotachograph (p < 0.0001). Significant colonization of the water-sealed spirometer was apparent after the third day of the study. The microorganisms most frequently isolated were penicillium sp. (62%), Pseudomonas fluorescens (32%), and Burkholderia cepacea (48%). Distal tubing, water and water-bell were the parts of the water-sealed spirometer that showed higher colonization counts (> or = 10(4) colony-forming units (cfu).mL-1). No transmission sequence of potentially pathogenic microorganisms from equipment to patients or vice versa could be demonstrated. In summary, the water-sealed spirometer frequently became colonized by microorganisms. The potential hazard of such equipment as reservoirs of microorganisms suggests a need for the implementation of new hygiene measures for their maintenance.

The role of the gastric reservoir in ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a common complication of mechanical ventilation with an incidence ranging from 9-70% and averaging around 25%. The pathogenesis of VAP requires abnormal oropharyngeal and gastric colonisation and then aspiration of these contents into the lower airways. Another co-existing mechanism could be direct oropharyngeal or lower airways inoculation of microorganisms through contaminated respiratory therapy equipment. Ventilator-associated pneumonia develops easily if aspiration or inoculation of microorganisms occur in patients with artificial airways and in whom mechanical, cellular and/or humoral defences are altered. Both host factors and treatments may alter pulmonary defence mechanisms; these too may contribute to the development of VAP. An alternative mechanism to explain VAP is bacterial translocation, although this mechanism is still under investigation. Figure 1 illustrates a schema of the pathogenesis of VAP. In this paper we review the possible role of the gastric reservoir in the aetiology of VAP, emphasising the following issues: 1. Risk factors for gastric colonisation 2. Clinical evidence of gastric aspiration to the lower airways in mechanically ventilated patients 3. Clinical evidence and controversies surrounding the role of the gastric reservoir in ventilator-associated pneumonia 4. The role of bacterial translocation as a mechanism for the development of VAP 5. A summary of prophylactic measures.

Hospital-acquired pneumonia: coverage and treatment adequacy of current guidelines.

The American Thoracic Society (ATS) guideline for hospital-acquired pneumonia (HAP) released in 1996 and the Trouillet classification published in 1998 supply different rational foundations for the classification of patients with HAP and for the selection of initial antibiotic therapy. The aims of this study were to assess the level of bacterial coverage and to assess and validate the adequacy of antibiotic strategy of each of these classifications. Intensive care unit-admitted patients (n=71) with suspicion of HAP were evaluated. The ATS and Trouillet classifications demonstrated an accuracy to predict the causative microorganism of 91% and 83% respectively. The ATS and Trouillet antibiotic treatment recommendations were adequate in 79% and 80% of the patients, respectively. The microorganisms implicated in the treatment inadequacy of the ATS guideline were Pseudomonas aeruginosa (n=3), Acinetobacter baumanii (n=1), Stenotrophomonas maltophilia (n=1) and methicillin-resistant Staphylococcus aureus (n=1). P. aeruginosa was implicated with Trouillet treatment inadequacy. The current recommendations for empirical antibiotic treatment of hospital-acquired pneumonia (American Thoracic Society and Trouillet) showed a good ability to predict the involved pathogen. However, considering the resistance pattern of the isolated pathogens, both classifications demonstrated a rather lower treatment adequacy; the main reason was the failure to treat highly resistant strains.

Evaluation of culture techniques for identification of catheter-related infection in hemodialysis patients.

A prospective study was conducted over eight months to evaluate the usefulness of two culture techniques using different catheter parts for detection of bacterial colonization or catheter-related bacteremia in patients with jugular or subclavian hemodialysis catheters. A combination of semiquantitative culture of the external surface and quantitative culture of the intraluminal surface of the intradermal catheter segment provided the best means of detecting catheter colonization. For detection of catheter-related bacteremia, this combination had 100% sensitivity and a positive predictive value similar to the actual rate of catheter-related bacteremia.

Diagnostic value of telescoping plugged catheters in mechanically ventilated patients with bacterial pneumonia using the Metras catheter.

A new guiding technique, Metras catheter (MC), for blindly introducing a telescoping plugged catheter (TPC) was applied to 25 mechanically ventilated patients with suspected bacterial pneumonia (BPN). Results obtained with TPC-MC were compared with those obtained with TPC using a conventional fiberoptic bronchoscope (FB) in random order. The diagnosis of BPN was definitely confirmed in 18 patients. In 7 patients, all TPC samples (MC and FB) were sterile, and a diagnosis other than BPN was proved. In the former group, colony-forming units equal to or greater than 10(3)/ml of one or more microorganisms were obtained in 61% of TPC-MC and in 66% of TPC-FB samples. These percentages increased to 64 and 71%, respectively, when 4 patients with previous antibiotic treatment were excluded from the study group. Agreement was observed between microorganisms cultured from both TPC samples in 11 of 18 patients with proved BPN (61%). Complete disparity was seen only in 2 patients (11%). Two patients developed a self-limiting hemoptysis after the TPC procedure (MC and FB, respectively). We conclude that TPC-MC is both a sensitive and specific technique for the diagnosis of BPN in mechanically ventilated patients. Because the diagnostic value of TPC-MC is similar to that of TPC-FB, we propose that the MC be used in patients receiving mechanical ventilation when the FB is not available. The simplicity and lower cost of this new system are important advantages to be considered over the fiberoptic bronchoscope.

[Antibody-coated bacteria and quantitative culture in sputum samples from patients with bronchiectasis]. / Bacterias recubiertas de anticuerpos y cultivo cuantitativo en las muestras de esputo de los pacientes con bronquiectasias.

The results of the quantitative culture of sputum samples from patients with bronchiectasis were compared with those obtained in the same samples with the detection of antibody-coated bacteria (ACB), in the acute phase of the disease (group I), after antibiotic therapy (group II), and in the phase of clinical stability (group III). In quantitative cultures at least one potentially pathogen species was isolated, at a concentration of greater than or equal to 10(6) colony forming units/ml in the 7 sputum samples from group I, in 4 of the 5 samples from group II, and in 10 of the 11 samples from group III. The immunofluorescence technique detected ACB in all samples from group I and group II, and in 10 of the 11 from group III. The sample from group III in which ACB were not detected was the same in which potentially pathogen organisms were not detected by culture.

Pulmonary aspiration of gastric contents in patients receiving mechanical ventilation: the effect of body position.

OBJECTIVE: To determine if the semirecumbent position (45-degree angle) decreases aspiration of gastric contents to the airways in intubated and mechanically ventilated patients. DESIGN: A randomized, two-period crossover trial. SETTING: Respiratory intensive care unit. PATIENTS: Nineteen patients requiring intubation and mechanical ventilation. INTERVENTIONS: Patients were studied in the supine and semirecumbent positions on two separate days. MEASUREMENTS: After technetium (Tc)-99m sulphur colloid labeling of gastric contents, sequential radioactive counts in endobronchial secretions were measured at 30-minute intervals over a 5-hour period. Samples of endobronchial secretions, gastric juice, and pharyngeal contents were obtained for qualitative bacterial cultures. RESULTS: Mean radioactive counts in endobronchial secretions were higher in samples obtained while patients were in the supine position than in those obtained while patients were in the semirecumbent position (4154 cpm compared with 954 cpm; P = 0.036). Moreover, the aspiration pattern was time-dependent for each position: For the supine position, radioactivity was 298 cpm at 30 min and 2592 cpm at 300 min (P = 0.013); for the semirecumbent position, radioactivity was 103 cpm at 30 min and 216 cpm at 300 min (P = 0.04). The same microorganisms were isolated from stomach, pharynx, and endobronchial samples in 32% of studies done while patients were semirecumbent and in 68% of studies done while patients were in the supine position. CONCLUSIONS: We conclude that the supine position and length of time the patient is kept in this position are potential risk factors for aspiration of gastric contents. Elevating the head of the bed for patients who can tolerate the semirecumbent position may be a simple, no-cost prophylactic measure.

Use of elastin fibre detection in the diagnosis of ventilator associated pneumonia.

BACKGROUND: Elastin fibre detection could be a simple and reliable marker of ventilator associated pneumonia. To confirm this, a prospective study was undertaken to evaluate the diagnostic yield of elastin fibre detection in the diagnosis of ventilator associated pneumonia. METHODS: Seventy eight mechanically ventilated patients were evaluated by examining endotracheal aspirates for the presence of elastin fibres. All patients were previously treated with antibiotics. Quantitative bacterial cultures of endotracheal aspirates and protected specimen brush samples were also performed. Patients were classified into three diagnostic categories: group 1, definite pneumonia (n = 25); group 2, probable pneumonia (n = 35); and group 3, controls (n = 18). RESULTS: Patients with definite and probable pneumonia were grouped together. The presence of elastin fibres in endotracheal aspirate samples was more frequent in groups 1 and 2, being found in 19 of the 60 patients compared with five of the control group. Although the presence of elastin fibres had a low sensitivity (32%), it was a reasonably specific marker (72%) of pneumonia. This specificity increased to 86% and 81% respectively when only Gram negative bacilli and Pseudomonas aeruginosa pneumonia were considered. Again, calculated sensitivity was 43% and 44% when analysing cases infected by Gram negative bacilli and Ps aeruginosa, respectively. The negative predictive value of the detection of elastin fibres in pneumonia caused by Ps aeruginosa was 81%. Detection was more frequent with infection by Gram negative bacilli (14/19), particularly with Ps aeruginosa (8/14). By contrast, pneumonia due to Gram positive cocci or non-bacterial agents uncommonly resulted in positive elastin fibre preparations (4/19, 21%). When analysing patients with and without chronic obstructive pulmonary disease, the diagnostic value of elastin fibre detection did not change. CONCLUSIONS: Potassium hydroxide preparation of elastin fibres is a rapid and simple specific marker of ventilator associated pneumonia and may be a useful technique to help diagnose pulmonary infections in mechanically ventilated patients, although this assessment is at present limited to patients without adult respiratory distress syndrome.

Re-intubation increases the risk of nosocomial pneumonia in patients needing mechanical ventilation.

In order to confirm that re-intubation can be a risk factor of nosocomial pneumonia in mechanically ventilated patients, a case-control study was performed. Forty consecutive patients needing re-intubation were selected as cases. Each case was paired with a matched control for the previous duration of mechanical ventilation (+/- 2 d). Nineteen (47%) of the cases developed pneumonia after re-intubation compared with 4 (10%) of the controls (odds ratio [OR] = 8.5; 95% confidence interval [CI] 1.7 to 105.9; p = 0.0007). After adjusting for age, sex, and presence of prior bronchoscopy, the conditional logistic regression analysis demonstrated that re-intubation was the only significant factor related to the development of pneumonia (OR: 5.94; 95% CI 1.27 to 22.71; p = 0.023). Sixteen (73%) of the 22 patients lying semirecumbent during the interval between extubation and re-intubation developed nosocomial pneumonia versus three (16%) of the 18 in supine position (p = 0.001). These results indicate that semirecumbency during the period between extubation and re-intubation may play a role in nosocomial pneumonia development in patients who need re-intubation. Total intensive care unit stay (19.4 +/- 10 versus 13.9 +/- 11.9 days, p = 0.0008) and crude mortality (35 versus 20%, p = 0.14) were also higher in re-intubated patients when compared with controls. We conclude that re-intubation is a risk factor for ventilator-associated pneumonia and might be avoided in a substantial number of cases.