Incorporating Lung Ultrasound in Clinical Pulmonary Infection Score as an Added Tool for Diagnosing Ventilator-associated Pneumonia: A Prospective Observational Study from a Tertiary Care Center.

Background: Clinical pulmonary infection score (CPIS) is an established diagnostic parameter for ventilator-associated pneumonia (VAP). Lung ultrasound (LUS) is an evolving tool for diagnosing VAP. Various scores have been proposed for the diagnosis of VAP, taking LUS as a parameter. We proposed whether replacing LUS with chest radiograph in CPIS criteria will add to the diagnosis of VAP. The current study was done to evaluate the diagnostic accuracy of LUS alone and in combination with clinical and microbiological criteria for VAP by replacing chest radiograph with LUS in CPIS. Materials and methods: We conducted a prospective single-center observational study including 110 patients with suspected VAP to investigate the diagnostic accuracy of LUS. Quantitative mini-bronchoalveolar lavage (mini-BAL) culture was considered the gold standard for diagnosis of VAP. Here, the authors have explored the combination of LUS, clinical, and microbiology parameters for diagnosing VAP. On replacing chest radiograph with LUS, sono-pulmonary infection score (SPIS) and modified SPIS (SPIS-mic, SPIS-cult) was formulated as a substitute for CPIS. Results: Overall LUS performance for VAP diagnosis was good with sensitivity, specificity, positive or negative predictive value, and positive or negative likelihood ratios of 91.3%, 70%, 89%, 75%, 3, and 0.1, respectively. Adding microbiology culture to LUS increased diagnostic accuracy. The areas under the curve for SPIS and modified SPIS were 0.808, 0.815, and 0.913, respectively. Conclusion: The diagnosis of VAP requires agreement between clinical, microbiological, and radiological criteria. Replacing chest radiograph with LUS in CPIS criteria (SPIS) increases diagnostic accuracy for VAP. Adding clinical and culture data to SPIS provided the highest diagnostic accuracy. Clinical parameters along with lung ultrasound increase diagnostic accuracy for VAP. How to cite this article: Samanta S, Patnaik R, Azim A, Gurjar M, Baronia AK, Poddar B, et al. Incorporating Lung Ultrasound in Clinical Pulmonary Infection Score as an Added Tool for Diagnosing Ventilator-associated Pneumonia: A Prospective Observational Study from a Tertiary Care Center. Indian J Crit Care Med 2021;25(3):284-291.

Higher mini-BAL total protein concentration in early ARDS predicts faster resolution of lung injury measured by more ventilator-free days.

The protein concentration of alveolar edema fluid in acute respiratory distress syndrome (ARDS) is dynamic. It reflects alveolar flooding during acute injury, as well as fluid and protein clearance over time. We hypothesized that among ARDS patients treated with low tidal volume ventilation, higher concentrations of protein in mini-bronchoalveolar lavage (mBAL) samples would predict slower resolution of lung injury and worse clinical outcomes. Total protein and IgM concentrations in day 0 mBAL samples from 79 subjects enrolled in the aerosolized albuterol (ALTA) ARDS Network Albuterol Trial were measured by colorimetric assay and ELISA, respectively. Linear regression models were used to test the association of mBAL proteins with clinical outcomes and measures of length of illness, including ventilator-free days (VFDs). Median mBAL total protein concentration was 1,740 µg/ml [interquartile range (IQR): 890-3,170]. Each 500 µg/ml increase in day 0 mBAL total protein was associated with an additional 0.8 VFDs [95% confidence interval (CI): 0.05-1.6, P value = 0.038]. Median mBAL IgM concentration was 410 ng/ml (IQR: 340-500). Each 50 ng/ml increase in mBAL IgM was associated with an additional 1.1 VFDs (95% CI 0.2-2.1, P value = 0.022). These associations remained significant and were not attenuated in multivariate models adjusted for age, serum protein concentration, and vasopressor use in the 24 h before enrollment. Thus, higher mBAL total protein and IgM concentrations at day 0 are associated with more VFDs in patients with ARDS and may identify patients with preserved alveolar epithelial mechanisms for net alveolar fluid clearance.

NMR-Based Metabolic Snapshot from Minibronchoalveolar Lavage Fluid: An Approach To Unfold Human Respiratory Metabolomics.

The utility of mini bronchoalveolar lavage (mBAL) and its applicability in metabolomics has not been explored in the field of human respiratory disease. mBAL, "an archetype" of the local lung environment, ensures a potent technique to get the snapshot of the epithelial lining fluid afflicted to human lung disorders. Characterization of the mBAL fluid has potential to help in elucidating the composition of the alveoli and airways in the diseased state, yielding diagnostic information on clinical applicability. In this study, one of the first attempts has been made to comprehensively assign and detect metabolites in mBAL fluid, extracted from human lungs, by the composite use of 800 MHz 1D and 2D NMR, J-resolved homonuclear spectroscopy, COSY, TOCSY, and heteronuclear HSQC correlation methods. A foremost all-inclusive sketch of the 50 metabolites has been corroborated and assigned, which can be a resourceful archive to further lung-directed metabolomics, prognosis, and diagnosis. Thus, NMR-based mBALF studies, as proposed in this article, will leverage many more prospective respiratory researches for routine clinical application and prove to be a viable approach to mirror the key predisposing factors contributing to the onset of lung disease.

Feasibility of the modified mini-bronchoalveolar lavage techniques using a nasogastric suction catheter and polytetrafluoroethylene bronchoscopic suction catheter in diagnosing bilateral pneumonia: a pilot study.

Background: The adequacy of actual lower respiratory tract samples collected using the current collection technique is debated. Endotracheal aspiration is commonly insufficient and can be contaminated with colonization from the proximal airway. Diagnostic bronchoscopy is the standard method for collecting specimens from the lower respiratory tract. However, it is usually unavailable in resource-limited settings. At present, noninvasive methods with the mini-bronchoalveolar lavage (BAL) catheter are used to collect specimens from the lower respiratory tract. Compared with the nasogastric (NG) tube, the polytetrafluoroethylene (PTFE) catheter, a modified mini-BAL catheter that suctions the more distal part of the tracheobronchial tree, can collect actual lower respiratory tract specimens. Methods: This prospective open-label pilot study included patients aged >18 years who were diagnosed with bilateral pneumonia and who required mechanical ventilation. Lower respiratory tract samples were collected via endotracheal aspiration, mini-BAL using an NG tube, and mini-BAL using a PTFE bronchoscopic catheter. Data on return fluid volume, white blood cell (WBC) count, microbiologic information obtained via quantitative culture, and each procedure-related complication were recorded. Results: The return fluid volumes of the NG tube and PTFE groups were 50 and 40 mL, respectively. The median WBC counts were 245 cells/cumm3 in the NG tube group and 305 cells/cumm3 in the PTFE group. Culture from endotracheal aspiration detected polymicrobial organisms in 8 (20.0%) patients. Further, 19 (47.5%) patients in the NG tube group and 18 (45.0%) in the PTFE group presented with polymicrobial organisms. Approximately 10% of patients developed mini-BAL-related complications, including arrhythmia (2.5%), mild hypoxemia (2.5%), and mild bleeding (5.0%). Conclusions: The two modified mini-BAL techniques are feasible in diagnosing patients with pneumonia requiring mechanical ventilation. The mini-BAL technique is more likely to detect polymicrobial organisms compared with endotracheal aspiration, which can then identify the causative polymicrobial organism of ventilator associated pneumonia (VAP) and lead to antibiotic adjustment. Moreover, it is easy to perform, can yield adequate specimens, and has few complications.

Evaluation of blind nasotracheal suctioning and non-bronchoscopic mini-bronchoalveolar lavage in critically ill patients with infectious pneumonia: a preliminary study.

BACKGROUND: We evaluated the diagnostic performance and safety of combined blind nasotracheal suctioning and non-bronchoscopic mini-bronchoalveolar lavage (mini-BAL) to obtain respiratory secretion specimens from spontaneously breathing, non-intubated patients with infectious pneumonia in intensive care. METHODS: Patients suspected of having infectious pneumonia were included prospectively. Three samples were obtained: expectorated sputum, nasotracheal suctioning, and mini-BAL via a double telescopic catheter (Combicath). Under local anesthesia, nasotracheal suctioning was done according to standard recommendations. Then mini-BAL was performed; the bronchial catheter serves as a guide for the mini-BAL catheter, and tracheal position is verified via colorimetric capnography. RESULTS: We included 36 subjects (29 men, median age 69 y, median Simplified Acute Physiology Score II 32), of which 32 (89%) underwent nasotracheal suctioning and mini-BAL, and from 13 (36%) we collected expectorated sputum. Based on colorimetric capnography confirmation of the tracheal position, 75% (24/32) of the successful combined procedures were achieved on the first attempt. The median duration of the combined procedure was 7 min. Bacterial pneumonia was diagnosed in 24/36 (67%) subjects, among whom 21 (88%) had undergone successful nasotracheal suctioning and mini-BAL, respectively, for 8/21 (38% [95% CI 0.17-0.58%] and 14/21 (67% [95% CI 0.46-0.86%]). Mini-BAL diagnosed a significantly higher percentage of bacterial pneumonias than did nasotracheal suctioning. Expectorated sputum yielded no diagnoses. CONCLUSIONS: Blind nasotracheal suctioning confirmed via colorimetric capnography allows microbiological diagnosis, and can be enhanced by non-bronchoscopic mini-BAL. Colorimetric capnography helps confirm bronchial tube position. Non-bronchoscopic mini-BAL is a novel and feasible way to collect bronchial secretions without fibroscopy. (ClinicalTrials.gov NCT00763620.).

Study for diagnostic efficacy of minibronchoalveolar lavage in the detection of etiologic agents of ventilator-associated pneumonia in patients receiving antibiotics / 결핵

BACKGROUND: Early diagnosis and proper antibiotic treatment are very important in the management of ventilator-associated pneumonia (VAP) because of its high mortality. Bronchoscopy with a protected specimen brush (PSB) has been considered the standard method to isolate the causative organisms of VAP. However, this method burdens consumer economically to purchase a PSB. Another useful method for the diagnosis of VAP is quantitative cultures of aspirated specimens through bronchoscopic bronchoalveolar lavage (BAL), for which the infusion of more than 120 ml of saline has been recommended for adequate sampling of a pulmonary segment. But occasionally it leads to deterioration of the patient's condition. We studied the diagnostic efficacy of minibronchoalveolar lavage (miniBAL), which retrieves only 25 ml of BAL fluid, in the isolation of causative organisms of VAP. METHODS: We included 38 consecutive patients (41 cases) suspected of having VAP on the basis of clinical evidence, who had received antibiotics before the bronchoscopy. The two diagnostic techniques of PSB and miniBAL, which were performed one after another at the same pulmonary segment, were compared prospectively. The cut-off values for quantitative cultures to define causative bacteria of VAP were more than 10(3) colony-forming units (cfu)/ml for PSB and more than 10(4) cfu/ml for BAL. RESULTS: The amount of instilled normal saline required to retrieve 25 ml of BAL fluid was 93 +/- 32 ml (mean +/- SD). The detection rate of causative agents was 46.3% (19/41) with PSB and 43.9% (18/41) with miniBAL. The concordance rate of PSB and miniBAL in the bacterial culture was 85.4% (35/41). Although arterial blood oxygen saturation dropped significantly (p<0.05) during (92 +/- 10 %) and 10 min after (95 +/- 3 %) miniBAL compared with the baseline (97 +/- 3 %), all except 3 cases were within normal ranges. The significantly elevated heart rate during (125 +/- 24/min, p<0.05) miniBAL compared with the baseline (111 +/- 22/min) recovered again in 10 min after (111 +/- 26/min) miniBAL. Transient hypotension was developed during the procedure in two cases. The procedure was stopped in one case due to atrial flutter. CONCLUSION: MiniBAL is a safe and effective technique to detect the causative organisms of VAP.