Nonbronchoscopic bronchoalveolar lavage for the diagnosis for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome

Lower Respiratory Tract Coinfection in the ICU: Prevalence and Clinical Significance of Coinfection Detected via Microbiological Analysis of Bronchoalveolar Lavage Fluid With a Comparison of Invasive Methodologies

Pneumonia remains a significant cause of morbidity and mortality, with increasing interest in the detection and clinical significance of coinfection. Further investigation into the impact of bronchoalveolar lavage (BAL) sampling methodology and efficient clinical utilization of microbiological analyses is needed to guide the management of lower respiratory tract infection in the ICU.

Personalizing the Management of Pneumonia

Pneumonia is a highly prevalent disease with considerable morbidity and mortality. However, diagnosis and therapy still rely on antiquated methods, leading to the vast overuse of antimicrobials, which carries risks for both society and the individual. Furthermore, outcomes in severe pneumonia remain poor. Genomic techniques have the potential to transform the management of pneumonia through deep characterization of pathogens as well as the host response to infection. This characterization will enable the delivery of selective antimicrobials and immunomodulatory therapy that will help to offset the disorder associated with overexuberant immune responses.

Pneumocystis carinii pneumonia in patients with and without HIV infection

Advances in the prevention and treatment of Pneumocystis carinii pneumonia in HIV infected patients have led to a decrease in the incidence and improved outcomes. Pneumocystis carinii pneumonia continues to be problematic in non-HIV infected immunocompromised patients.

Non-bronchoscopic bronchoalveolar lavage in the microbiological diagnosis of pneumonia in mechanically ventilated patients

A prospective study comparing standardized non-bronchoscopic bronchoalveolar lavage (sNB-BAL) and non-specific endotracheal aspirate (NsETA) in the microbiological diagnosis of pneumonia in mechanically ventilated patients is described. One hundred episodes in 82 mechanically ventilated patients with or without radiological and clinical diagnostic criteria of pneumonia were studied. NsETA and sNB-BAL was performed on the day of study. Fifty-one patients had pneumonia (21 ventilator-associated, 12 hospital-acquired, 18 community-acquired) and 49 had no pneumonia as defined by widely accepted clinico-radiological criteria. The sNB-BAL was found to be significantly more specific (0. 73) compared to NsETA (0.35) for the microbiological diagnosis of pneumonia. Colonization rates with NsETA were significantly higher compared to sNB-BAL (P value <0.0001). No patient had complications attributable to the sNB-BAL procedure. We conlude that sNB-BAL is a safe, effective, sensitive, specific and inexpensive procedure for the serial evaluation of pneumonia in mechanically ventilated patients.

Role of bronchoscopy in AIDS

The differential diagnosis of pulmonary disorders in the HIV-infected individual is broad. Clinical features and chest radiographs may point towards a diagnosis but cannot reliably establish one. It is important to know the conditions in which bronchoscopy, BAL, and TBB are likely to be diagnostic, just as it is to know when other invasive or noninvasive procedures may be more useful. Finally, the incidence of transmission of infections such as tuberculosis during bronchoscopy and cross-contamination of patients with an improperly sterilized bronchoscope, cannot be overemphasized.

Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) remains an important complication of AIDS. Advances have been made in establishing the taxonomy of the organism but the life cycle of the organism and pathogenetic mechanisms of disease remain obscure. In HIV patients the incidence of PCP has decreased because of widespread use of prophylaxis and survival of those with PCP has improved with use of adjunctive corticosteroid therapy. Less toxic drug therapies are still needed as well as better noninvasive diagnostic techniques.

The role of bronchoalveolar lavage in the diagnosis of bacterial pneumonia

Bronchoalveolar lavage (BAL) has become an invaluable diagnostic tool with important clinical implications in both opportunistic infections and the pulmonary pathology of immunologic disease. Until recently, the use of BAL was limited primarily to two areas: the study of interstitial lung diseases and the diagnosis of lung infections by opportunistic microorganisms in severely immunocompromised patients with lung infiltrates. Over the past decade, the use of BAL has been expanded to include the conventional diagnosis of bacterial pneumonia in non-immunocompromised patients. In the past, different clinical studies proposed using BAL to quantify cultures in the sample obtained as a means of increasing the tool's effectiveness. Recent developments have led to a number of newer applications of BAL, such as bronchoscopic BAL, non-bronchoscopic BAL and protected BAL. The most important use of BAL in the non-immunocompromised patient is the diagnosis of pneumonia in the mechanically ventilated patient.

Comparison of Ballard catheter bronchoalveolar lavage with bronchoscopic bronchoalveolar lavage

BACKGROUND

Bronchoscopic bronchoalveolar lavage (BAL) in mechanically ventilated patients requires a large endotracheal tube, physician expertise, expensive equipment, and support staff.

METHODS

The Ballard BAL catheter is a disposable coude tip 16F device that can be attached to the endotracheal tube and ventilator circuit without loss of positive end-expiratory pressure (PEEP) and also allows supplemental delivery of oxygen between the 12F inner and outer catheters. The catheter is directed into the selected bronchus. The inner catheter with mushroom tip is then advanced until it wedges by feel. Thirteen patients at a tertiary care, university hospital, had BAL performed through both the bronchoscope and Ballard BAL catheter using five aliquots of 20 mL of normal saline solution each. The return was quantified and submitted for blinded, paired laboratory investigations, including Gram stain and quantitative culture, and special stains and cultures as clinically appropriate.

RESULTS

The procedure was well tolerated in all patients with no difference between devices in oxygen saturations; however, air leaks occurred in patients undergoing bronchoscopy and compromised safety in one. Two patients required reintubation to facilitate passage of the bronchoscope. The bronchoscopic BAL return averaged 49 mL (range, 5 to 85 mL) while BAL catheter averaged 37 mL (range, 18 to 70 mL) both being sufficient for all desired investigations except one patient who had undergone bronchoscopy. All were of excellent quality based on microscopy. The BAL results were concordant in nine patients: two Pneumocystis carinii, one Candida, one Streptococcus agalactiae, one Streptococcus pneumoniae, and no infection in four. Diagnoses of tuberculosis and Enterococcus (confirmed by blood culture) were obtained by the Ballard BAL catheter only. Kaposi's sarcoma and metastatic histiosarcoma were visualized by bronchoscope only. Two patients had compassionate plea use of the Ballard BAL catheter because of a small endotracheal tube. Hemorrhage secondary to lupus was documented in one and nosocomial infection was excluded in the other.

CONCLUSIONS

The Ballard BAL catheter allows easy, safe BAL, without loss of diagnostic yield, when visualization is not required in mechanically ventilated patients. The Ballard BAL catheter allows maintenance of PEEP when used with the supplied adapter and can be used with small endotracheal tubes.

A simple method of bronchoalveolar lavage

Twenty-eight ventilated paediatric intensive care patients, mean age 4.1 +/- 4 years, who had had a simple method of nonbronchoscopic bronchoalveolar lavage (NB-BAL) performed were reviewed. The NB-BAL technique involved blindly wedging a 5 or 8F infant feeding catheter endobronchially and lavaging one millilitre per kg saline using a syringe. Adequate samples were collected in 87% of the NB-BAL specimens. In two of the four inadequate specimens, Pneumocystis carinii was still able to be identified. Additional information not obtained from the tracheal aspirate culture was seen in 71% of the NB-BAL samples. One-third of the patients also had a bronchoscopic BAL or a lung biopsy performed and the culture results were all identical to those obtained from NB-BAL. No significant complications were seen. Oxygenation and ventilation were not altered by the technique. We conclude that NB-BAL performed using a syringe and infant feeding catheter is a simple and cheap method that produces good alveolar samples in the majority of cases.

Nonbronchoscopic bronchoalveolar lavage in mechanically ventilated infants: technique, efficacy, and applications

Bronchoalveolar lavage with the fiberoptic bronchoscope is commonly used for the diagnosis of pulmonary infections in mechanically ventilated adults and children. However, its use for intubated infants is precluded because the small artificial airway does not permit the passage of the bronchoscope. We have developed a technique for nonbronchoscopic bronchoalveolar lavage, performed via a sterile, disposable feeding tube. We have used this technique in 15 infants with diffuse interstitial disease and/or atelectasis, while they were intubated and mechanically ventilated. The volume of the lavage effluent averaged 70.3% of the volume instilled. Specific diagnosis on the basis of the cytologic evaluation and/or culture of the lavage fluid was possible in 9 (60%) patients. Two patients with atelectasis showed radiographic evidence of improvement following the procedure. There were no complications. We conclude that nonbronchoscopic bronchoalveolar lavage is well tolerated, and clinically useful in small, mechanically ventilated infants with respiratory failure due to diffuse pulmonary disease. This technique provides a lower risk alternative to more invasive, and costly procedures.

Nonbronchoscopic approach to bronchoalveolar lavage in children with artificial airways

Bronchoalveolar lavage (BAL) performed with a fiberoptic bronchoscope (FOB) is a useful method for sampling alveolar contents. Since the smallest FOB with a channel has a diameter of 3.6 mm, BAL is difficult to accomplish through artificial airways (AA) less than 5.0 mm I.D. We used a 4F balloon wedge pressure catheter to perform BAL through small AA. Supplemental O2 or ventilatory support was delivered via an adaptor through which the catheter was introduced. After it was passed distal to the AA, the balloon was inflated with normal saline (NS) to a predetermined volume, and advanced until resistance was felt. The balloon was deflated, advanced slightly, and then reinflated to achieve airway occlusion. Five aliquots of 0.75 mL/kg of NS were used for BAL. The procedure was performed in 20 children from 1 month (950 g) to 6 1/2 years of age (median, 9 months). All specimens contained abundant alveolar macrophages, indicating good recovery of alveolar contents. Clinically significant information was obtained in 17 (85%) cases, and no patient required an open lung biopsy. In conclusion, nonbronchoscopic bronchoalveolar lavage is a valuable method for obtaining alveolar contents in children with small AA that preclude the use of an FOB, and it obviates the need for open lung biopsy in many patients. This technique could be used as a research tool for measuring constituents of alveolar contents in infants and small animals.

Bronchoscopy in the intensive care unit

The development of the flexible, fiberoptic bronchoscope has made bronchoscopic examinations possible in ICU patients undergoing mechanical ventilation. Over the years, the number of such procedures has greatly increased, with both diagnostic and therapeutic objectives, such as performing difficult intubation, management of atelectasis and hemoptysis, diagnosis of nosocomial pneumonia in ventilated patients, and early detection of airway lesions in selected situations, such as high-frequency ventilation. The complication rate can be kept low if the endoscopist has a precise knowledge of the many pathophysiological and technical facets particular to bronchoscopy under these difficult conditions. This article reviews some of these aspects, in the light of our personal experience.

Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid

Substantial efforts have been devoted to improving the means for early and accurate diagnosis of ventilator-associated (VA) pneumonia in intensive care unit (ICU) patients because of its high incidence and mortality. A good diagnostic yield has been reported from quantitative cultures of bronchoalveolar lavage (BAL) fluid or a protected specimen brush, both obtained by fiberoptic bronchoscopy. As bronchoscopy requires specific skills and is costly, we evaluated a simpler method to obtain BAL fluid, that is, by a catheter introduced blindly into the bronchial tree. Quantitative cultures from bronchoscopically sampled BAL (B-BAL) and blindly nonbronchoscopically collected BAL (NB-BAL) were assessed for sensitivity, specificity, and predictive value for the diagnosis of VA pneumonia. A total of 40 pairs of samples were examined in 28 patients requiring prolonged mechanical ventilation and presenting a high risk of developing pneumonia. For comparison with bacteriologic data we defined a clinical score for pneumonia ranging from zero to 12 using the following variables: body temperature, leukocyte count, volume and character of tracheal secretions, arterial oxygenation, chest X-ray, Gram stain, and culture of tracheal aspirate. To quantify the bacteria in BAL the bacterial index (BI) was used, defined as the sum of the logarithm of the number of bacteria cultured per milliliter of BAL fluid. A good correlation between clinical score and quantitative bacteriology was observed (r = 0.84 for B-BAL and 0.76 for NB-BAL; p less than 0.0001). Similar to studies in baboons, patients with pulmonary infection could be distinguished by a BI greater than or equal to 5 with a sensitivity of 93% and a specificity of 100% (B-BAL).(ABSTRACT TRUNCATED AT 250 WORDS)

Tracheal catheters in patients with acquired immunodeficiency syndrome for the diagnosis of Pneumocystis carinii pneumonia

The diagnosis of Pneumocystis carinii pneumonia (PCP) often requires bronchoscopy. In 82 consecutive human immunodeficiency virus (HIV)-positive patients suspected of having PCP, we passed a 14-F catheter into the trachea under local anesthesia without intubation, instilled saline solution, and then collected the secretions by aspiration. Bronchoscopy with collection of bronchial washings and performance of bronchoalveolar lavage (BAL) was then performed and the results were compared. The catheter results were identical with the results of BAL in 77 of 82 patients. This inexpensive technique may provide a reasonable early step in the diagnosis of PCP.

Comparison of nonbronchoscopic bronchoalveolar lavage to open lung biopsy for the bacteriologic diagnosis of pulmonary infections in mechanically ventilated patients

We compared nonbronchoscopic bronchoalveolar lavage (NB-BAL) with open lung biopsy to determine the etiological diagnosis of lung infiltrates in patients requiring mechanical ventilation. NB-BAL was performed via a cuffed reusable 7F catheter generally used for right heart catheterization (BAL-C). In 13 patients, BAL-C and open lung biopsy were performed in the same lobe immediately after death when the ventilator was still functioning. No organism was cultured from BAL-C cultures when histopathologic examination of the lung showed no pneumonia and lung culture isolated no organism. Among the 10 positive BAL-C cultures, lung biopsy showed histologic pneumonia in 9 cases. Among these 9 pneumonia cases, 14 organisms were isolated in lung cultures and BAL-C correctly identified the causative agent in 13 cases. BAL-C appears to be an effective and safe procedure in the diagnosis of pulmonary infections in patients under mechanical ventilation who have previously received antibiotic therapy.

A review of pulmonary cytopathology in the acquired immunodeficiency syndrome

Over the past 6 yr, we have observed an increase in cytologic specimens from the respiratory tract in patients suspected or known to have AIDS, from 7 of 81,031 cases in 1982 to 1,231 of 55,333 in 1987. Based on our experience with 1,140 patients, this article reviews the technical and morphologic evaluation of pulmonary cytologic specimens from AIDS patients.

Nonbronchoscopic lung lavage for diagnosis of opportunistic infection in AIDS

Thirty patients known to have or suspected of having acquired immunodeficiency syndrome (AIDS) were evaluated for opportunistic pulmonary infection using a double lumen lavage catheter (DLL). Lavage specimens obtained were cytocentrifuged and initially stained by the Papanicolaou technique as a means of rapid evaluation for Pneumocystis carinii. If no opportunistic organism was identified, the patient underwent further diagnostic investigations. In 18 patients receiving mechanical ventilatory support, the procedure was performed via the endotracheal tube. Twelve patients who were less severely ill underwent the procedure via the transnasal route. In 43 percent (13/30), opportunistic infections were diagnosed by DLL. Twelve had P carinii, one of whom had cytomegalovirus and another of whom had Herpes simplex viruses, and one with Toxoplasma gondii. Thus, the sensitivity for all opportunistic infections was 86 percent (12/14). The volume of fluid recovered averaged 93 percent of that instilled. There was no significant difference between prelavage and postlavage PaO2. In this group of patients, double lumen lavage obviated the need for more invasive and expensive procedures.