Pneumoperitoneum is defined as the presence of free air within the peritoneal cavity. In approximately 90% of cases, it results from gastrointestinal perforation and requires urgent surgical intervention. The remaining 10% represent nonsurgical (spontaneous) pneumoperitoneum, in which no perforation is detected and conservative management is usually sufficient. Etiologically, nonsurgical pneumoperitoneum can be classified into pseudopneumoperitoneum, intrathoracic, abdominal, gynecological, and idiopathic categories. Intrathoracic causes include air migration from the chest during mechanical ventilation, cardiopulmonary resuscitation, or spontaneous pneumothorax. Abdominal causes involve rupture of cysts in pneumatosis cystoides intestinalis, perforation of hepatic or splenic abscesses, barotrauma, endoscopic complications, and infections by gas-producing bacteria. Gynecological causes are associated with vaginal insufflation, sexual intercourse, or instrumentation. In a minority of cases, the etiology remains idiopathic. Differentiating between surgical and nonsurgical pneumoperitoneum is crucial, as unnecessary laparotomies are reported in up to one quarter of patients. Decision--making requires comprehensive clinical evaluation, thorough physical examination, and imaging studies, particularly contrast-enhanced CT. In the absence of peritonitis or sepsis, conservative management with observation, antibio-tics, and symptomatic therapy is recommended. Accurate dia-gnosis and awareness of the rare, nonsurgical causes of pneumoperitoneum are essential to prevent unnecessary surgical interventions and to optimize patient care in this potentially critical condition.

Chronic obstructive pulmonary disease remains a leading cause of death worldwide, with emphysema contributing significantly to dyspnea, exercise limitation, and mortality. Bronchoscopic lung volume reduction (BLVR) using endobronchial valves (EBVs) has emerged as a minimally invasive, reversible alternative to lung volume reduction surgery for carefully selected patients with severe emphysema who remain symptomatic despite optimal medical therapy. EBVs are one-way valves placed bronchoscopically to achieve complete lobar occlusion, inducing atelectasis of the most diseased lung segments while allowing better ventilated parenchyma to expand, thereby improving respiratory mechanics and reducing hyperinflation. Landmark randomized controlled trials demonstrated that BLVR using EBVs produces significant improvements in forced expiratory volume in one second (FEV1), exercise capacity, and quality of life comparable to surgical lung volume reduction but with reduced morbidity and mortality. Critical to treatment success is meticulous patient selection based on emphysema distribution, absence of collateral ventilation, and appropriate physiologic parameters. Pneumothorax represents the most common serious complication, occurring in approximately 26% of patients, though paradoxically, it indicates successful lobar occlusion and predicts favorable long-term outcomes. As the most extensively studied BLVR, endobronchial valve therapy represents a cornerstone intervention for appropriately selected patients with severe emphysema.

Acute hypoxemic respiratory failure (AHRF) represents one of the most common and clinically challenging indications for invasive mechanical ventilation in the intensive care unit, characterized by profound etiological heterogeneity that demands accurate diagnosis to guide treatment. While clinical history, physical examination, and laboratory data remain essential, they are often insufficient to reliably discriminate among conditions such as acute respiratory distress syndrome (ARDS), cardiogenic pulmonary edema, and pneumonia-particularly in mechanically ventilated patients. Lung imaging has therefore emerged as an indispensable complement to clinical assessment. In this narrative review, we systematically describe the physical principles, clinical applications, and limitations of the imaging modalities currently available in critical care: chest X-ray (CXR), computed tomography (CT), lung ultrasound (LUS), electrical impedance tomography (EIT), and positron emission tomography (PET). CXR remains the most widely used bedside tool but is constrained by low sensitivity and significant interobserver variability. CT is the gold standard for morphological and quantitative lung phenotyping, enabling the assessment of recruitability, baby lung characterization, and the identification of complications, but requires patient transport and exposes patients to ionizing radiation. LUS offers real-time, bedside evaluation of aeration with high diagnostic accuracy for pneumothorax and pleural effusion, and is increasingly integrated into revised ARDS diagnostic criteria. EIT enables continuous, radiation-free monitoring of regional ventilation distribution and positive end-expiratory pressure (PEEP)-guided titration directly at the bedside. While PET provides unparalleled quantification of regional inflammation and ventilation-perfusion mismatch, it currently remains a purely investigative research tool. Finally, we discuss emerging technological and AI-driven advances-including dual-energy CT, next-generation EIT, and deep learning algorithms-that are poised to transform lung imaging from a passive diagnostic tool into an active, personalized guide to respiratory management.

Objective: Prolonged intubation in critically ill patients can lead to airway injury and infection. Early percutaneous dilational tracheostomy (PDT) is preferred in the intensive care unit (ICU), but the optimal guidance technique remains debated. We aimed to compare outcomes of PDT facilitated by three different guidance techniques: blind landmark, bronchoscopy-guided, and ultrasound-guided. Methods: This single-center retrospective cohort study included adults who underwent bedside PDT between 2013 and 2023. Patients were grouped by technique: bronchoscopy-guided (Group A), ultrasound-guided (Group B), and blind landmark technique (Group C). Demographics, illness severity, procedural details, complications, infection rates, and outcomes including mortality were analyzed. Results: A total of 254 patients were analyzed (118 bronchoscopy-guided, 50 ultrasound-guided, and 86 blind). Baseline illness severity scores were comparable among groups, although admission diagnosis distributions differed significantly. Tracheostomy-related complications occurred in 32% of patients, most commonly minor bleeding (~23%), with no significant intergroup differences. Early mortality following PDT (≤72 h) and post-procedural complication rates were similar among techniques. Pneumothorax and tracheoesophageal fistula were rare events. Ventilator liberation and decannulation rates did not differ significantly between groups. ICU and hospital mortality were numerically higher in the blind group; however, these findings should be interpreted cautiously because of the retrospective design and differences in admission diagnoses and case-mix between groups. Conclusions: All three PDT guidance techniques showed comparable procedural safety, with no significant differences in early complications, infection rates, or ventilator liberation. Although blind PDT was associated with higher observed mortality, this cannot be causally attributed to the technique, given the retrospective design and potential confounders. Ultrasound guidance offers practical procedural advantages and should be considered where available, pending prospective randomized confirmation.

Background/Objectives: Totally implantable venous access ports (TIVAPs) are commonly used in oncology for long-term venous access, but catheter tip malpositioning can lead to complications. Intracavitary electrocardiography (IC-ECG) provides real-time tip guidance, although data on clinical outcomes and patient satisfaction remain limited. This study evaluates postoperative complications, catheter function, and patient comfort and satisfaction after TIVAP implantation using ultrasound and IC-ECG guidance. Methods: This retrospective single-center study included adults with solid cancers who received TIVAP implants for chemotherapy from June 2021 to September 2024. Procedures used the right internal jugular vein, with ultrasound guidance and the Seldinger technique; catheter tip placement was guided by IC-ECG. Chest X-rays were obtained to assess for early complications and tip position. Primary outcomes were comfort and satisfaction; secondary outcomes included catheter tip position, catheter complications, and usability. Results: Among 213 screened patients, 192 were included (79 females, 113 males; mean age 60.83 ± 12.19 years). The catheter tip was located within the target zone in 149 patients (77.6%). Success rates were 98.44% (n = 189/192) for blood aspiration, 97.90% (n = 186/190) for port ease of use, 98.95% (n = 189/191) for overall satisfaction, and 98.43% (n = 188/191) for willingness to recommend. Discomfort occurred in 6.25% (n = 12/192) of patients. Comfort improved significantly from day1 to day7 (p < 0.001). Complication rates included hematoma (1.56%, n = 3), pneumothorax (0.52%, n = 1), venous thrombosis (1.56%, n = 3), local infection (2.08%, n = 4), systemic infection (0.52%, n = 1), and catheter occlusion (2.08%, n = 4). Catheter blood aspiration success was 93.75% (n = 180/192). Conclusions: In this retrospective cohort, TIVAP implantation via the right internal jugular vein under ultrasound and IC-ECG guidance was associated with low complication rates, favorable catheter function, and high patient satisfaction. Prospective, multicenter, and comparative studies are needed to determine whether ECG-guided tip positioning improves long-term clinical and patient-centered outcomes.

Birt-Hogg-Dubé syndrome (BHDS) is a hereditary cancer syndrome caused by pathogenic variants in the FLCN gene. BHDS is characterized by clinical heterogeneity and similarities with other non-hereditary diseases, which can complicate diagnosis. The aim of our study was to analyze FLCN variants in Russian patients and select the optimal diagnostic approach. We studied 121 unrelated patients suspected for BHDS and 29 of their relatives. Germline variants were analyzed using Sanger sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA). Variant annotation was performed according to the ACMG and AMP recommendations. Pathogenic and likely pathogenic (P/LP) FLCN variants were identified in 20.7% of patients, including six new variants. The distribution of FLCN variants in our cohort was consistent with data obtained from other authors. The mean age of patients with P/LP variants was higher than of those without: 46.91 versus 33.8 years (p < 0.05), suggesting the necessity to apply diagnostic criteria in young patients more carefully. The most common clinical manifestation of BHDS was pulmonary cysts/pneumothorax, while the most informative were alterations involving at least two of three organ systems, which was present in all patients with the P/LP variants, but only in 54% without them (p = 0.001). BHDS diagnostics involves sequencing exons 4-14 of the FLCN gene in patients with proposed clinical criteria. If the result is negative, extensive FLCN deletions are excluded using MLPA, and, in the absence of CNV, WGS is performed.