Experience with fibreoptic bronchoscopy in the diagnosis of pulmonary shadows in renal transplant recipients over a 12-year period

Utility of fiber-optic bronchoscopy in pulmonary infections among abdominal solid-organ transplant patients: A comprehensive review

Pulmonary infections are frequent complications in abdominal solid-organ transplantation (aSOT) which may threaten patient and allograft survival. Accurate diagnosis and treatment of pulmonary infections in this population can be challenging. Immunosuppressive therapy not only increases the risk of acquiring opportunistic and non-opportunistic infections, but it also impairs the inflammatory responses associated with microbial invasion which in an otherwise normal host produce clinical and radiologic responses that allow for early identification of the offending pathogen. Serologic testing is not a reliable diagnostic modality. Direct microbiological sampling is often necessary to make a definitive diagnosis early in the clinical course to optimize timely, targeted therapy while reducing the risk of developing antimicrobial resistance, and minimize adverse effects of therapy, if any. Fiber-optic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) or transbronchial lung biopsy (TBB) offers such diagnostic advantage and possesses a potential therapeutic value too. This comprehensive review discusses the potential benefits of FOB alongside its risks and complications, indications and contraindications, and techniques. Additionally, the essay highlights FOB's utility and yield specifically with regard to type and timing of infections in aSOT patients.

Invasive diagnostic strategies in immunosuppressed patients with acute respiratory distress syndrome

Immunosuppression predisposes the host to development of pulmonary infections, which can lead to respiratory failure and the development of acute respiratory distress syndrome (ARDS). There are multiple mechanisms by which a host can be immunosuppressed and each is associated with specific infectious pathogens. Early invasive diagnostic modalities such as fiber-optic bronchoscopy with bronchoalveolar lavage, transbronchial biopsy, and open lung biopsy are complementary to serologic and noninvasive studies and assist in rapidly establishing an accurate diagnosis, which allows initiation of appropriate therapy and may improve outcomes with relative safety.

Spectrum of Pulmonary Infections in Renal Transplant Recipients in the Tropics: A Single Center Study

BACKGROUND

Pulmonary infections have been implicated as the most common cause of infection related mortality in renal transplant recipients. An appropriate empirical treatment of post transplant pulmonary infections requires knowledge of the spectrum of the microorganisms involved in causing these infections. Besides this knowledge, an aggressive diagnostic approach including the use of invasive tests is often essential to make an early diagnosis for instituting timely and appropriate therapy. We carried out a prospective cohort study to analyze the spectrum of pulmonary infections in these patients and study the utility of bronchoalveolar lavage (BAL) in the diagnosis of the same.

METHODS

From September 2001 to December 2002, 428 patients were under follow up with the department. In all, 40 renal transplant recipients reported with 44 episodes of pulmonary infection during this study period. All patients underwent detailed and appropriate investigations including specific laboratory tests, sputum analysis, X-ray chest, CT and BAL. The spectrum of the causative organisms and the utility of BAL as compared to the other methods of diagnosis were studied and compared.

RESULTS

Out of the 44 episodes of pulmonary infection evaluated, single causative organism could be found in only 24 (54.5%) episodes and multiple etiologies were found in 15 (34.1%) episodes. No definitive cause could be found in 5 episodes. Out of 57 organisms isolated in the 44 episodes, 20 (45.4 %) were bacteria, 16 (36.3 %) each were M. tuberculosis and fungus, 3 were CMV infection and 2 were nocardia. BAL gave a diagnostic yield of 75.8% (25 out of 33 cases). Nine of forty patients died (mortality rate 22.5%) of which 6 deaths could be attributed directly to pulmonary infection. Out of these 9 patients who died, cause of pulmonary infection was bacterial in 5, fungal in 2 and CMV disease in 1. In one patient, organism could not be isolated.

CONCLUSIONS

Our study has shown that more than 1/3rd of pulmonary infections in renal transplant recipients can be attributed to multiple organisms. Bacterial infections were the commonest cause of post transplant pulmonary infection. Tuberculosis is common cause of pulmonary infection in these patients in our set up. Because of its high diagnostic yield, BAL should be considered in all patients with suspected pulmonary infections in the post transplant period.

Etiology and microbial patterns of pulmonary infiltrates in patients with orthotopic liver transplantation

STUDY OBJECTIVE

To evaluate the etiology and microbial patterns of pulmonary infiltrates in liver transplant patients using a bronchoscopic diagnostic approach and the impact of diagnostic results on antimicrobial treatment decisions.

DESIGN

A prospective cohort study.

SETTING

A 1,000-bed tertiary-care university hospital.

PATIENTS AND METHODS

Fifty consecutive liver transplant patients with 60 episodes of pulmonary infiltrates (33 episodes during mechanical ventilation) were studied using flexible bronchoscopy with protected specimen brush (PSB) and BAL.

RESULTS

A definite infectious etiology was confirmed in 29 episodes (48%). Eighteen episodes corresponded to probable pneumonia (30%), 10 episodes had noninfectious etiologies (17%), and 3 remained undetermined (5%). Opportunistic infections were the most frequent etiology (16/29, 55%, including 1 mixed etiology). Bacterial infections (mainly Gram-negative) accounted for 14 of 29 episodes (48%), including 1 of mixed etiology. The majority of bacterial pneumonia episodes (n = 10, 71%) occurred in period 1 (1 to 28 days posttransplant) during mechanical ventilation, whereas opportunistic episodes were predominant in periods 2 and 3 (29 to 180 days and > 180 days posttransplant, respectively; n = 14, 82%). Microbial treatment was changed according to diagnostic results in 21 episodes (35%).

CONCLUSIONS

Microbial patterns in liver transplant patients with pulmonary infiltrates corresponded to nosocomial, mainly Gram-negative bacterial pneumonia in period 1, and to opportunistic infections in period 2 and, to a lesser extent, period 3. A comprehensive diagnostic evaluation including PSB and BAL fluid examination frequently guided specific antimicrobial therapy.

The role of fibre-optic bronchoscopy in solid organ, transplant patients with pulmonary infections

Organ transplantation is currently the standard therapy for patients with end-stage organ dysfunction. The immunosuppression caused by this therapy increases the rate of infection, particularly in the lungs. Early diagnosis is extremely important and fibre-optic bronchoscopy is a helpful tool in reaching diagnosis. Knowing the timing of various pathogens following transplantation, and the radiological picture as well as the prophylactic regimen, is helpful when specific pathogens are suspected. Bronchoscopy with bronchoalveolar lavage and transbronchial biopsies are particularly helpful in diagnosis of bacterial cytomegalovirus (CMV) and pneumocytosis carinii pneumocytosis, and is considered a safe procedure. Open lung biopsy is reserved for those who have negative bronchoscopy with a reasonable prognosis.

Transbronchial biopsy in the diagnosis of pulmonary infiltrates in immunocompromised patients

Bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) frequently are performed in the investigation of immunocompromised patients with lung disorders. The risk-benefit ratio of TBB currently is debated, since several authors have found that the less invasive BAL may provide as much information as TBB, with the avoidance of some biopsy-related side effects. We retrospectively evaluated 157 instances of bronchoscopy carried out on 142 immunocompromised patients, with both BAL and TBB performed in every case. Immunosuppressant conditions were HIV infection (79), hematologic malignancies (36), and antirejection therapy in renal transplant recipients (27). Transbronchial biopsy provided a diagnostic yield significantly higher than that obtained by BAL in all categories investigated; diagnostic rates were 77.3% for TBB and 47.6% for BAL (p < 0.001) in patients with HIV infection, 55 and 20% (p < 0.001) in patients with hematologic malignancies, and 57.5 and 27.2% (p < 0.001) in renal transplant recipients. Looking at the whole series, the diagnostic rates of TBB and BAL were 67.5 and 36.3%, respectively (p < 0.001), with a total additional yield of 33% provided by TBB, while in only 2% of cases BAL gave rise to diagnostic information not achieved by TBB. Considering that side effects followed TBB at a negligible rate (2.5%), we believe that TBB should be routinely carried out in these patients once the diagnostic strategy has been oriented to bronchoscopy.