Pulmonary function tests (PFTs), particularly spirometry, are the reference standard for assessing airflow limitation in respiratory diseases such as chronic obstructive pulmonary disease (COPD) and interstitial pulmonary disease. However, spirometry requires substantial patient cooperation and may be unreliable in children, the elderly, and patients with cognitive impairment, and its use was further limited during the COVID-19 pandemic. Dynamic chest radiography (DCR), which captures sequential thoracic images during respiration at low radiation dose, has emerged as a promising modality for evaluating respiratory dynamics, but its potential to quantitatively estimate pulmonary function through radiomic analysis remains insufficiently explored.

This study aimed to determine the potential of radiomic features of the lung on DCR to predict pulmonary function (FEV₁, forced expiratory volume in the first second; FVC, forced vital capacity) and to classify patients at high risk (FEV₁/FVC).

We retrospectively analysed data from 151 patients. The DCRs at end-inspiration (EI), end-expiration (EE), and the respiratory phase of maximum variation in the lung area from EI to EE (insp2exp_vmax) or from EE to EI (exp2insp_vmax) were defined based on the lung area. A respiratory motion map was also calculated. To combine the defined DCR and respiratory motion map, feature extraction was performed, followed by the least absolute shrinkage and selection operator (LASSO). Predictive regression and classification models with various radiomic feature combinations (nos. 1-6) were constructed for pulmonary function. Pearson's correlation coefficients (R) were calculated for FEV₁ and FVC, and the area under the curve (AUC) was calculated for FEV₁/FVC. Our predictive models were compared using the conventional formula.

We constructed a predictive regression and classification model for FEV₁, FVC, and FEV₁/FVC ratio using DCR images and a respiratory motion map. The model accuracy with DCR at each respiratory phase and the respiratory motion map-based radiomic features was better than that of the conventional method.

In this single-center retrospective study, radiomic features extracted from DCR at multiple respiratory phases combined with respiratory motion maps showed promise for estimating pulmonary function, outperforming conventional demographic-based prediction. External validation in multi-center cohorts is warranted before clinical translation.

To evaluate whether day-of-procedure ambient ozone exposure is associated with pneumothorax after CT-guided lung biopsy.

This retrospective single-centre study included 160 CT-guided lung biopsies performed between January 2018 and February 2026. Environmental data from the day of biopsy were assigned from the nearest national monitoring station. The primary outcome was any pneumothorax on post-biopsy CT; the secondary outcome was drainage-requiring pneumothorax. Multivariable logistic regression included ozone exposure, emphysema, and access route through dependent lung area (ARDA). Ozone was analysed as a continuous variable per 10 μg/m³ and, exploratorily, using a ROC-derived threshold of ≥75.8 μg/m³. Restricted cubic splines assessed nonlinearity. Sensitivity models adjusted for needle size, biopsy system, operator identity, and season. Drainage-requiring pneumothorax was analysed using Firth logistic regression.

Pneumothorax occurred after 86 of 160 biopsies (53.8%), and 13 biopsies (8.1%) required drainage. Ozone was not associated with pneumothorax when modelled linearly (OR, 1.09 per 10 μg/m³; 95% CI, 0.97-1.23; p = 0.167). In exploratory threshold modelling, ozone ≥ 75.8 μg/m³ was associated with pneumothorax (OR, 2.76; 95% CI, 1.39-5.61; p = 0.004). Emphysema increased pneumothorax odds (OR, 2.16; 95% CI, 1.03-4.68; p = 0.047), whereas ARDA was protective (OR, 0.23; 95% CI, 0.11-0.45; p < 0.001). Spline analysis supported nonlinearity (p = 0.001). For drainage-requiring pneumothorax, only emphysema was significant.

Ambient ozone showed an exploratory nonlinear association with pneumothorax after CT-guided lung biopsy, with a threshold signal around 70-80 μg/m³. ARDA was protective, whereas emphysema was associated with drainage-requiring pneumothorax.

Despite normal lung imaging and preserved pulmonary and cardiac function, many patients with long COVID continue to experience persistent respiratory symptoms. This study aimed to quantify the pulmonary blood and airway volumes in patients with long COVID compared with healthy controls and to evaluate the associations of COVID-19 vaccination with these imaging parameters.

Patients with long COVID presenting with persistent respiratory symptoms despite normal laboratory findings, pulmonary function tests, chest radiography, and chest computed tomography (CT) were prospectively enrolled. CT datasets were analyzed using functional respiratory imaging (FRI), incorporating the three-dimensional reconstruction and automated segmentation of the lungs, airways, and pulmonary vasculature. Quantitative imaging parameters were compared with those of historical healthy controls from the COPDGene study, matched for age, sex, body mass index, comorbidities, and pulmonary function test parameters.

Thirty patients with long COVID (mean 221 ± 128 days after confirmed SARS-CoV-2 infection) and 30 matched healthy controls were included. Compared with controls, patients with long COVID demonstrated significantly lower pulmonary blood volumes in small and large pulmonary vessels, together with significantly reduced intrapulmonary airway volumes. Within the long COVID cohort, full COVID-19 vaccination was associated with a significantly greater small-vessel pulmonary blood volume and lobar airway volume compared with non-vaccinated individuals.

These findings indicate that patients with long COVID exhibit persistent reductions in pulmonary blood and airway volumes despite normal conventional imaging and pulmonary function tests, suggesting the presence of subtle microvascular and small-airway abnormalities that may contribute to ongoing respiratory symptoms. The association between full COVID-19 vaccination and higher small-vessel pulmonary blood and lobar airway volumes suggests a potential protective effect on pulmonary structure and function; however, these findings require confirmation in larger, prospective controlled studies.

The COVID-19 pandemic profoundly disrupted healthcare utilization patterns at both primary care (PC) and hospital emergency department (ED) levels. This study aimed to assess the impact of the pandemic on referral patterns from PC to a hospital ED and on the resource consumption associated with those referrals.

A descriptive, retrospective, longitudinal comparative study with multivariable sensitivity analyses was conducted at a first-level hospital of Madrid (Spain). All consecutive PC-to-ED referrals received during two observation windows were included: a pre-pandemic period (1 June-31 December 2019; n=946) and a Later-Pandemic period (1 January-30 June 2022; n=1797). Sociodemographic characteristics, referral form quality, diagnostic specialty, and in-ED resource utilization variables were collected and compared using χ2, Student's t-test, and Mann-Whitney U tests as appropriate. To assess seasonal confounding, multivariable logistic and ordinal regression models adjusting for calendar season, age, and sex were performed for the primary resource-utilization outcomes.

A total of 2743 referrals were analyzed. The monthly referral rate increased by approximately 122% between periods (135/month vs. 300/month). A statistically significant but clinically negligible difference in mean age was observed (53.1±18.3 vs. 54.9±19.0 years; p=0.015); no significant sex differences were found. Referral form completion improved significantly for clinical history (94.5% vs. 98.2%; p<0.001). Orthopedics referrals nearly tripled (5.8% vs. 18.4%), while respiratory/COVID-19-related referrals represented 22.0% of the 2022 caseload. ED length of stay between 3 and 6 h increased from 13.0% to 42.8% (p<0.001), while the need for urgent blood tests fell from 68.9% to 56.0% (p<0.001), hospital admission from 68.4% to 10.9% (p<0.001), and referral to another center from 12.3% to 0.9% (p<0.001). In multivariable sensitivity analyses, the period effect remained statistically significant after adjustment for calendar season, age, and sex for hospital admission (adjusted OR =0.062; 95% CI: 0.037-0.106; p<0.001) and urgent blood test utilization (adjusted OR =0.470; 95% CI: 0.326-0.678; p<0.001), although study period and season remain partly confounded by the non-overlapping design.

During the later-pandemic period, PC-to-ED referrals increased substantially while being associated with fewer complementary investigations and fewer hospital admissions. This study documents between-period differences in referral patterns and ED resource utilization rather than causal effects; the differences persisted after adjustment for seasonality but cannot be definitively attributed to the pandemic. Future multi-center longitudinal studies are needed to confirm these trends and clarify their underlying mechanisms.

Delayed initiation of mepolizumab may influence long-term disease control and the achievement of clinical and functional outcomes in patients with uncontrolled severe asthma (SUA), but no definitive conclusions have yet been established regarding the optimal timing for biologic initiation. The aim of this study was to evaluate, in a real-world clinical setting, the effect of delayed mepolizumab initiation-from the moment patients first met EMA eligibility criteria-on the treatment response (using the EXACTO scale), clinical remission (according to SEPAR-REMAS criteria) and lung function at 12 months and 3 years after treatment initiation.

We conducted a retrospective observational cohort study including 148 patients with SUA treated with mepolizumab from January 2017 to November 2024 in our hospital. Patients were stratified into tertiles according to delay: ≤5 months, 6-19 months, and >19 months. Baseline demographic, clinical, and lung function characteristics were analyzed.

Patients with shorter delay exhibited distinct significance baseline profiles, including higher eosinophil counts, lower BMI and current smoker, and better pre-treatment lung function (p < 0.05). Shorter delay was significantly associated with higher rates of good/complete response according to the EXACTO scale at both 12 months and 3 years (p < 0.05). Clinical remission rates were numerically higher in the early-treatment group, although differences did not reach statistical significance. No significant differences in lung function outcomes were observed between delay groups at either 12 months or 3 years.

In conclusion, earlier initiation of mepolizumab after meeting EMA criteria is associated with improved clinical response, although it does not significantly influence remission rates or lung function recovery. These findings underscore the importance of timely treatment initiation and reinforce the relevance of accurate phenotypic and endotypic characterization to optimize biologic selection in SUA.

Cervical spinal cord injury (SCI) carries a significant burden in Saudi Arabia, frequently resulting in permanent ventilator dependence and high morbidity. While laparoscopic diaphragmatic pacing (DP) has emerged as an alternative to long-term mechanical ventilation (MV) globally, regional evidence regarding its application within the Middle East remains limited. This study evaluates a single-center cohort of ventilator-dependent cervical SCI patients undergoing laparoscopic DP.

We conducted a retrospective analysis of all ventilator-dependent patients with cervical SCI admitted to a tertiary hospital in Riyadh between 2012 and 2024 who underwent laparoscopic DP after failing traditional weaning attempts. Inclusion criteria required at least 3 months of MV dependence, intraoperative diaphragmatic stimulability and a minimum one-year follow-up post-implantation. Across the entire cohort, the long-term follow-up duration reached a median of 60.0 months (interquartile range [IQR]: 36.0-84.0 months; range: 12.0-120.0 months).

Out of 30 initial candidates with cervical SCI, 28 patients (22 males, 6 females; median age 24.0 years (interquartile range [IQR]: 15.0-33.0 years)) were included. Patients had been on MV for a median of 13.0 months (IQR: 10.5-16.0 months) prior to the procedure. Utilizing a combined weaning success rate (complete or partial weaning), 26 patients (92.86%; 95% CI: 77.42-98.01%) were successfully transitioned to the pacing protocol, while 2 patients (7.14%) experienced DP failure. Complete (24 h) daily MV independence was achieved by 18 patients (64.29%), and partial weaning (≥4 h/day of MV-free time) was achieved by 8 patients (28.57%). Age at the time of injury ranged from 5 to 62 years. No major intraoperative or postoperative complications occurred. Minor exit-site skin irritation was observed in 3 patients (10.71%), all of which resolved completely with conservative local care alone without requiring antibiotic therapy.

In this selected single-center Saudi cohort of ventilator-dependent cervical SCI patients, laparoscopic DP was feasible and was associated with high rates of partial or complete ventilator-free breathing. Larger prospective multicenter studies with standardized selection criteria, safety reporting, respiratory outcomes, quality-of-life measures, and longer follow-up are needed.

COVID-19 has been linked to musculoskeletal complications, including femoral head avascular necrosis (AVN). Both COVID-19-related hypercoagulability and corticosteroid therapy have been proposed as contributing factors. This systematic review synthesizes current evidence on the occurrence, clinical characteristics, timing, and risk factors for femoral head AVN following COVID-19.

A PRISMA-compliant systematic search of PubMed, Embase, and Scopus identified observational studies and case series (≥10 patients) reporting femoral head AVN in adults or adolescents with confirmed COVID-19. Data on epidemiology, symptom onset, imaging findings, and corticosteroid exposure were narratively synthesized due to heterogeneity.

Fifteen eligible studies described patients with post-COVID femoral head AVN. Symptom onset ranged from days to >12 months after infection. Early MRI often revealed asymptomatic or low-grade disease. Corticosteroid exposure was common and strongly associated with AVN severity; however, several studies reported AVN in patients without steroid use, whether this reflects an independent contribution of COVID-19 or unrecognized confounding cannot be determined from the available uncontrolled data. Higher cumulative steroid doses, severe pulmonary involvement, and elevated inflammatory markers were consistently linked to more advanced AVN stages.

Femoral head AVN is an emerging post-COVID complication with variable timing and presentation. Corticosteroid exposure remains the principal risk factor; whether COVID-19 contributes independently of corticosteroids is unproven, and current evidence supports an association rather than a causal relationship. Awareness of this potential complication is warranted, although the role of early MRI screening remains to be established in prospective studies.

Background: The COVID-19 pandemic disrupted healthcare systems and antimicrobial stewardship, potentially altering antimicrobial resistance patterns. This study characterized temporal changes in the proportions of multidrug-resistant organisms (MDROs) and identified associated factors before and during the pandemic at a tertiary care hospital in northeastern Thailand. Methods: A single-center retrospective observational study was conducted at Roi Et Hospital, including 5458 culture-confirmed MDRO cases (2017-2022), stratified into pre-pandemic (2017-2019) and pandemic (2020-2022) periods. Pathogen-specific resistance proportions were compared using odds ratios (ORs) with 95% confidence intervals (CIs). Multivariable logistic regression identified independently associated factors within each period. Results: The proportion of MDRO cases classified as hospital-acquired increased from 40.71% to 57.41% (p < 0.001). Carbapenem-resistant Acinetobacter baumannii (CRAB) increased markedly (22.87% to 76.11%; OR 10.75, 95% CI 9.43-12.26), followed by carbapenem-resistant Enterobacterales (CRE) (4.05% to 21.61%; OR 6.54, 95% CI 5.84-7.32) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) (14.32% to 27.15%; OR 2.23, 95% CI 1.87-2.65; all p < 0.001). Vancomycin-resistant Enterococcus (VRE) declined significantly (OR 0.41, 95% CI 0.25-0.68; p < 0.001). Methicillin-resistant Staphylococcus aureus (MRSA) showed a higher proportion among clinical isolates (3.28% to 6.34%; OR 2.01, 95% CI 1.42-2.83), although without a consistent annual trend. In multivariable analyses, ICU admission was independently associated with lower odds of CRE (aOR 0.52) and CRPA (aOR 0.63) and with higher odds of CRAB (aOR 2.13; all p < 0.001). Conclusions: The COVID-19 pandemic was associated with a major proportional shift toward carbapenem-resistant Gram-negative pathogens, with distinct profiles of associated factors across CRAB, CRE, and CRPA. These findings highlight the need for pathogen-specific infection prevention and antimicrobial stewardship strategies during healthcare system disruptions.

Evidence on the prognostic utility of biological markers in critically ill patients with COVID-19 across different geographic altitudes remains limited.

The aim of this study was to determine the prognostic value of inflammatory and hematological markers, particularly the neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume (MPV), for mortality risk in critically ill patients with COVID-19 receiving invasive mechanical ventilation and living at different geographic altitudes.

A multicenter retrospective cohort study was conducted using secondary data from a clinical database. A total of 362 critically ill patients with COVID-19 admitted to intensive care units (ICUs) between April 2020 and March 2022 were included. Patients were treated at three hospitals in Ecuador located at different altitudes: sea level (4 m above sea level [masl]), moderate altitude (2200 masl), and high altitude (2850 masl). Clinical, laboratory, and outcome data were obtained from electronic medical records.

The mean age was 54.44 years, and 71.27% of patients were male. Post hoc, altitude-stratified NLR and MPV thresholds were associated with increased odds of ICU mortality: at sea level, NLR ≥ 12.50 and MPV ≥ 8.80 fL; at moderate altitude, NLR ≥ 11.50 and MPV ≥ 9.80 fL; and at high altitude, NLR ≥ 16.30 and MPV ≥ 9.00 fL.

In mechanically ventilated patients with critical COVID-19, NLR and MPV values above post hoc, altitude-stratified cutoff points were associated with higher ICU mortality. However, because each altitude stratum corresponded to a different hospital and these thresholds were not ROC-derived or internally/externally validated, these findings should be interpreted as exploratory and hypothesis-generating.

Background: The differential diagnosis of respiratory distress syndrome (RDS) and congenital pneumonia (CP) in newborns remains a complex clinical challenge due to the similarity in their clinical manifestations and their potential to coexist. Objective: We aimed to determine differential diagnostic predictors of RDS and CP in newborns by using mathematical modeling and machine learning methods. Methods: A retrospective cohort study was conducted; de-identified medical records of 244 newborns (97 with RDS and 143 with CP) were collected to assess clinical, anamnestic, laboratory, and instrumental data by applying multiple regression analysis, ROC analysis, logistic regression models, and Random Forest. Results: Patients with CP presented with a more severe condition at admission (57.1% vs. 23.3%; p = 0.023), required mechanical ventilation (MV) more frequently (22.4% vs. 8.2%; p = 0.004), and were more often transferred to the intensive care unit (ICU) (77.3% vs. 55.7%; p = 0.001). They further had lower hemoglobin levels (151 ± 28 g/L vs. 164 ± 31 g/L; p = 0.001) and red blood cell counts (p = 0.021). Regression analysis demonstrated that the severity of the condition and the presence of cerebral ischemia were dependent on hemoglobin levels in the case of CP, while gestational age played a determining role in RDS. The machine learning models achieved an accuracy of 0.69 and an area under the curve (AUC) of 0.82 (Random Forest). The key predictors for differential diagnosis of RDS were low gestational age, hyperbilirubinemia, and congenital heart defects, while for CP, they were hemoglobin < 151 g/L, lymphocytes < 4.8 × 10³/μL, oxygen saturation < 90-91%, and cerebral ischemia. Conclusions: The use of mathematical modeling methods made it possible to identify prognostically significant predictors for the differential diagnosis of RDS and CP. The resulting models are best viewed as proof-of-concept tools for hypothesis generation and future research, as external validation is necessary before they can be considered for clinical use.