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.

Follow-up evaluation of pulmonary function and computed tomography findings in chronic kidney disease patients after COVID-19 infection.

Pulmonary complications are common after SARS-CoV2- infection. However, data on pulmonary sequelae of COVID-19 after recovery in dialysis patients are limited. We determined the prevalence of abnormal lung function tests and CT findings and investigate the association factors impacting pulmonary dysfunction. This prospective observational cohort study enrolled 100 patients with stage 5 chronic kidney disease (CKD) undergoing dialysis who had recovered from COVID-19 for ≥3 months. Pulmonary function test (PFT) and chest computed tomography (CT) were performed. Demographic data and laboratory results were recorded. The mean patient age was 55.15 ± 12.84 years. Twenty-one patients (21%) had severe COVID-19, requiring mechanical ventilation or oxygen supplementation. Pulmonary function tests revealed a restrictive pattern in 41% (95% confidence interval [CI], 31.73-50.78;) and an obstructive pattern in 7.29% (95% CI, 3.19-13.25) patients. The severe group showed PFT test results similar to the non-severe group, with three patients showing severe obstructive lung disease. The CT scan findings included reticulation (64%), multifocal parenchymal band (43%), ground glass opacities (32%), and bronchiectasis (28%). The median total CT score was 3 (interquartile range, 1-8.5). The CT score and PFT findings showed no association with pulmonary dysfunction extent, except in bronchiectasis. Lung function indices were associated with abnormal CT findings. Abnormal CT findings (bronchiectasis, reticulation, and ground-glass opacities) was associated with higher oxygen requirements than normal CT findings (p = 0.008, bronchiectasis; p = 0.041, reticulation; p = 0.032, ground-glass appearance). Aside from CT findings and CRP levels, no significant lung abnormalities were observed in severe and non-severe patients. Some patients had residual symptoms at follow-up. The findings indicate persistence of both radiological and physiological abnormalities in dialysis patients after COVID-19. However, the prevalence of these abnormalities was comparable to that in the normal population; few patients experienced ongoing symptoms. Follow-up observations and evaluations are warranted. Trial registration. Clinicaltrials.gov Identifier: NCT05348759.

Performance and applications of bedside visual inspection of airway pressure-time curve profiles for estimating stress index in patients with acute respiratory distress syndrome.

To determine the performance of bedside visual inspection of airway pressure-time (Paw-t) curve profiles (VI) for estimating stress index (SI) in patients with acute respiratory distress syndrome (ARDS). A prospective study in 30 subjects with ARDS receiving mechanical ventilation at two peak inspiratory flow (PIF) settings: 60 or 40 L/min. For each study session, two physicians inspected real-time Paw-t waveforms from mechanical ventilator's monitoring screens at bedside for 30 s and interpreted which of the three patterns (tidal recruitment, noninjurious ventilation or tidal overdistension) the Paw-t curve profile was compatible with. Subsequently, the study was repeated again at the second PIF setting. SI was derived from a standardized dedicated software program and categorized into three groups: SI < 0.9, or tidal recruitment; SI = 0.9-1.05, or noninjurious ventilation; and SI > 1.05, or tidal overdistension. The lower PIF setting increased the sensitivity of VI to correctly estimate SI (75% vs. 50%; p = 0.005). At PIF 40 L/min, the likelihood ratio of a positive test was 3.6, 5.4 or 7 if the Paw-t curve profile was interpreted as noninjurious ventilation, tidal recruitment or tidal overdistension, respectively. The likelihood ratio of a negative test ranged from 0.55 for tidal recruitment to 0.32 and 0.19 for noninjurious ventilation and tidal overdistension, respectively. Experience in mechanical ventilation did not influence the accuracy. Bedside VI is moderately accurate for estimating SI and may be used to monitor injurious ventilation in patients with ARDS, in addition to plateau airway pressure.