Purpose: To identify pathogenic microorganisms and microbiological risk factors causing high morbidity and mortality in immunocompromised patients requiring invasive mechanical ventilation due to pneumonia. Methods: A retrospective single-center study was performed at the intensive care unit (ICU) of the Department of Internal Medicine at Heidelberg University Hospital (Germany) including 246 consecutive patients with hematological malignancies requiring invasive mechanical ventilation due to pneumonia from 08/2004 to 07/2016. Microbiological and radiological data were collected and statistically analyzed for risk factors for ICU and 1-year mortality. Results: ICU and 1-year mortality were 63.0% (155/246) and 81.0% (196/242), respectively. Pneumonia causing pathogens were identified in 143 (58.1%) patients, multimicrobial infections were present in 51 (20.7%) patients. Fungal, bacterial and viral pathogens were detected in 89 (36.2%), 55 (22.4%) and 41 (16.7%) patients, respectively. Human herpesviruses were concomitantly reactivated in 85 (34.6%) patients. As significant microbiological risk factors for ICU mortality probable invasive Aspergillus disease with positive serum-Galactomannan (odds ratio 3.1 (1.2-8.0), p = 0.021,) and pulmonary Cytomegalovirus reactivation at intubation (odds ratio 5.3 (1.1–26.8), p = 0.043,) were identified. 1-year mortality was not significantly associated with type of infection. Of interest, 19 patients had infections with various respiratory viruses and Aspergillus spp. superinfections and experienced high ICU and 1-year mortality of 78.9% (15/19) and 89.5% (17/19), respectively. Conclusions: Patients with hematological malignancies requiring invasive mechanical ventilation due to pneumonia showed high ICU and 1-year mortality. Pulmonary Aspergillosis and pulmonary reactivation of Cytomegalovirus at intubation were significantly associated with negative outcome.

Background/Objectives: There is an ongoing debate about the most advantageous anesthesia technique for carotid endarterectomy (CEA). From an anesthesiologic perspective, locoregional anesthesia (LRA) appears to offer significant benefits. However, the learning curve and complication rates for anesthesiologists newly performing ultrasound-guided LRA for CEA remain unclear and are to be examined in greater detail in this study. Methods: This retrospective, single-center study included all consecutive LRA administrations for CEA following the introduction of this procedure at a district hospital in Germany from November 2013 to November 2017. Nine board-certified anesthesiologists, initially inexperienced in LRA for CEA but with prior experience in other ultrasound-guided peripheral nerve blocks (PNBs), received theoretical training and supervision during their first six combined deep and superficial cervical plexus blocks under ultrasound guidance. The primary endpoint was the incidence of insufficient block quality, indicated by pain and restlessness or the additional need for analgesics. Secondary endpoints included LRA-associated complications. Patients were divided into four groups based on the number of previously performed LRA procedures by the attending anesthesiologist. Results: In 83 patients, LRA was performed by initially inexperienced anesthesiologists. Group A (patients managed by anesthesiologists performing their 1st to 3rd cervical plexus blockades) included 21 patients, Group B (blockades 4–6) included 12 patients, Group C (blockades 7–9) included 9 patients, and Group D (≥10 blockades) included 41 patients, respectively. The overall complication rate was 22% (18/83). Insufficient block quality occurred in 18.1% of patients (15/83), resulting in three conversions to general anesthesia (3.6%). Additional complications included dysphagia (n = 2) and Horner’s syndrome (n = 1). The incidence of insufficient block quality was significantly reduced (p = 0.008) after performing the first three blockades. Conclusions: Ultrasound-guided cervical plexus block for CEA appears to be a rapidly learnable anesthesia technique for anesthesiologists experienced in other ultrasound-guided PNBs, with a low risk of complications. After three supervised blockades, the failure rate of LRA decreases significantly.

Background and Objectives: Intra-abdominal hypertension (IAH) and acute respiratory distress syndrome (ARDS) are common concerns in intensive care unit patients with acute respiratory failure (ARF). Although both conditions lead to impairment of global respiratory parameters, their underlying mechanisms differ substantially. Therefore, a separate assessment of the different respiratory compartments should reveal differences in respiratory mechanics. Materials and Methods: We prospectively investigated alterations in lung and chest wall mechanics in 18 mechanically ventilated pigs exposed to varying levels of intra-abdominal pressures (IAP) and ARDS. The animals were divided into three groups: group A (IAP 10 mmHg, no ARDS), B (IAP 20 mmHg, no ARDS), and C (IAP 10 mmHg, with ARDS). Following induction of IAP (by inflating an intra-abdominal balloon) and ARDS (by saline lung lavage and injurious ventilation), respiratory mechanics were monitored for six hours. Statistical analysis was performed using one-way ANOVA to compare the alterations within each group. Results: After six hours of ventilation, end-expiratory lung volume (EELV) decreased across all groups, while airway and thoracic pressures increased. Significant differences were noted between group (B) and (C) regarding alterations in transpulmonary pressure (TPP) (2.7 ± 0.6 vs. 11.3 ± 2.1 cmH₂O, p < 0.001), elastance of the lung (E_L) (8.9 ± 1.9 vs. 29.9 ± 5.9 cmH₂O/mL, p = 0.003), and elastance of the chest wall (E_CW) (32.8 ± 3.2 vs. 4.4 ± 1.8 cmH₂O/mL, p < 0.001). However, global respiratory parameters such as EELV/kg bodyweight (−6.1 ± 1.3 vs. −11.0 ± 2.5 mL/kg), driving pressure (12.5 ± 0.9 vs. 13.2 ± 2.3 cmH₂O), and compliance of the respiratory system (−21.7 ± 2.8 vs. −19.5 ± 3.4 mL/cmH₂O) did not show significant differences among the groups. Conclusions: Separate measurements of lung and chest wall mechanics in pigs with IAH or ARDS reveals significant differences in TPP, E_L, and E_CW, whereas global respiratory parameters do not differ significantly. Therefore, assessing the compartments of the respiratory system separately could aid in identifying the underlying cause of ARF.

Acute hypoxemic respiratory failure is a critical challenge in intensive care. A substantial proportion of patients present with asymmetric acute lung injury (ALI), complicating management due to heterogeneous lung involvement. While lung-protective mechanical ventilation represents the standard of care, the optimal approach to positive end-expiratory pressure (PEEP) titration remains unclear. This study investigated the effects of transpulmonary pressure (TPP)-guided PEEP titration vs. a fixed PEEP strategy in a porcine model of unilateral ALI. A total of 14 pigs underwent ALI induction via unilateral surfactant depletion and were randomized to receive either a fixed PEEP of 5 cmH₂O or a PEEP targeting a slightly positive TPP at end-expiration. Over six hours, respiratory mechanics, high-resolution computed tomography (HRCT), histological lung injury scores (LIS), and plasma protein biomarkers were assessed. TPP-guided PEEP titration significantly lowered driving pressure and improved compliance compared to fixed low PEEP, suggesting more homogeneous tidal volume distribution. HRCT revealed less collateral injury in the initially non-injured lung in the TPP-guided group. However, histopathological LIS did not differ between groups. Exploratory cytokine profiling showed systemic inflammatory activation—including pro- and anti-inflammatory responses—only in the TPP-guided group. These findings indicate that TPP-guided PEEP titration may optimize ventilation by balancing alveolar recruitment and overdistension in asymmetric ALI, with clear effects on physiological and imaging parameters, but without parallel effects on cytokine responses. Further research is needed to assess its long-term impact and clinical relevance.

Early detection of acute lung injury (ALI) remains challenging, as conventional diagnostics rarely capture initial molecular changes. We therefore examined whether extracellular vesicles (EVs) in bronchoalveolar lavage fluid (BALF) can detect early regional injury and distinguish initial stress mechanisms in a porcine ALI model. Unilateral ALI was induced using Triton X-100, followed by six hours of mechanical ventilation with either fixed positive end-expiratory pressure (PEEP) at 5 cmH₂O or transpulmonary-pressure (TPP)-guided PEEP. Spatially separated BALF sampling allowed direct comparison between injured and contralateral mechanically stressed lungs. EV concentration and size distribution were quantified by nano-flow cytometry, while vesicular identity was confirmed by transmission electron microscopy and tetraspanin dot blot analyses. Furthermore, EV metrics were related to corresponding histologic injury scores. Across both PEEP strategies, EV concentration was markedly higher in both directly injured and contralateral mechanically stressed lungs compared with sham controls, indicating alveolar stress beyond the primary injury site. Median EV size differed significantly by injury type and correlated inversely with histologic injury, particularly with alveolar neutrophil infiltration. BALF-derived EV concentration and size may therefore provide complementary, spatially resolved molecular readouts of early ALI.