BMC Pulmonary Medicine最新文献

Background: Acute cellular rejection (ACR) is a common complication after lung transplantation (LTX) and it is considered a risk factor for chronic lung allograft dysfunction (CLAD). Lung transbronchial biopsy is still the gold standard for a correct diagnosis of ACR. The aim of the present study was to evaluate the predictive role of bronchoalveolar lavage (BAL) cellular composition in combination with CT scan features for the diagnosis of ACR.

Method: We retrospectively evaluated all LTX recipients who underwent transbronchial biopsies combined with BAL procedures and CT scan at a single Institution between January 2019 and October 2024 (n = 169). ACR histological diagnosis was made according to current guidelines, BAL analysis included percentage of cellular composition, lymphocytes' typing and microbiology. A qualitative analysis of specific CT was conducted by an expert thoracic radiologist.

Results: Among the 169 biopsies analyzed, 34% showed acute cellular rejection (ACR), predominantly grade A1 (68%). Patients with ACR exhibited significantly higher lymphocyte percentages in BAL (p = 0.025), and the cutoff of 25% showed 22% sensibility and 92% specificity for the diagnosis of ACR. Combing BAL findings with CT features, patients with lymphocyte ≥ 25% in BAL and concomitant pleural effusion showed 95.7% specificity of ACR. Infections were associated with elevated neutrophil levels in BAL (p = 0.026); eosinophil levels were significantly higher in patients with significant ACR (grade ≥ 2) and concomitant infection than those with infection only (p = 0.0014).

Conclusion: BAL cellular composition proved to be a strong predictive tool for the diagnosis of ACR. The lymphocyte threshold of 25% was able to distinguish patients with ACR, while the combination of increased BAL lymphocytes with ACR associated CT scan abnormalities especially pleural effusion significantly enhanced diagnostic accuracy. Elevated eosinophil levels were associated to more severe rejection and concomitant infection, highlighting their crucial role in the alloreactive immune response. These findings suggest the role of BAL and CT scan in combination as a valuable diagnostic tool in ACR diagnosis, although histological confirmation remains the gold standard.

Background: Acute respiratory failure is common in sepsis. When severe conditions like refractory hypoxemia or persistent CO2 retention occur, invasive mechanical ventilation (IMV) is required. The PaO2/FiO2 ratio is a key indicator for assessing acute respiratory failure severity and sepsis prognosis. This study investigates the early ICU trajectory of PaO2/FiO2 in septic patients requiring IMV for acute respiratory failure and its association with 28-day mortality.

Methods: This retrospective cohort study utilized the MIMIC-IV database to examine septic patients with acute respiratory failure receiving IMV. Group-based trajectory modeling (GBTM) classified PaO2/FiO2 trends over the first 96 h. Cox and logistic regression assessed associations between trajectory patterns and 28-day or ICU mortality.

Results: Among 2270 patients, ICU mortality was 27.1% and 28-day mortality 31.2%. Five distinct PaO2/FiO2 trajectories were identified. Compared to the persistently low trajectory group, patients in trajectory 5 (initially low PaO2/FiO2 that improved and stabilized at a mildly reduced level) had significantly lower risks of 28-day mortality (HR 0.73, 95% CI 0.61-0.87) and ICU mortality (OR 0.64, 95% CI 0.50-0.81).

Conclusion: In patients with sepsis-related acute respiratory failure receiving invasive mechanical ventilation, early dynamic patterns of PaO2/FiO2 in the ICU are closely associated with short-term outcomes. Compared to those with persistently low oxygenation levels, patients whose PaO2/FiO2 was initially low but improved and stabilized at a mildly reduced level within 96 h exhibited significantly lower risks of ICU and 28-day all-cause mortality. PaO2/FiO2 trajectories may serve as a valuable tool for early prognostic assessment in patients with sepsis.