Strenuous respiratory effort has been proposed as a second hit for the lungs, labeled as “patient self-inflicted lung injury” (P-SILI). This secondary exploratory analysis evaluated whether insufficient respiratory support is associated with biventricular myocardial injury and pulmonary microvascular ultrastructural changes in experimental acute lung injury. In rats, lung injury was induced through surfactant depletion, followed by 3 h of unsupported (standard oxygen therapy, 2L/min) or supported ventilation: protective mechanical ventilation (MV), continuous positive airway pressure (CPAP) 6 cmH2O, or high-flow nasal oxygen (HFNO) 4L/min. Subjects were assessed through general monitoring, arterial blood gas analysis, esophageal manometry (inspiratory effort), surface electromyography on the abdominal wall (expiratory effort), echocardiography (right ventricular outflow), and coagulation dysfunction analysis. An exploratory histological hypothesis-generating study on the right and left ventricular (RV and LV) myocardium was performed in all animals, and a quantitative scanning electron microscopy-based analysis of luminal permeability in small pulmonary vessels was completed only in four subjects per injured group. The primary endpoint was RV myocardial injury, while LV injury and pulmonary microvascular changes were considered secondary endpoints. The unsupported group presented higher heart rate, hypercapnia, increased arterial lactate levels, respiratory variation in pulmonary peak flow velocity, RV and LV myocardial injury, and incipient alterations in coagulation compared to MV and CPAP (all p < 0.05). All support therapies were associated with lower myocardial injury score: MV and CPAP showed the lowest RV injury, and HFNO the highest. Only MV was strongly associated with lower LV injury score (all p < 0.05). The Standard oxygen therapy and HFNO groups showed significantly higher luminal occlusion in small pulmonary vessels, consisting of erythrocyte-rich intravascular aggregates and amorphous material adherent to the vascular wall (all p < 0.05). Unsupported respiratory effort was associated with biventricular myocardial injury and pulmonary microvascular ultrastructural findings characterized by occlusive intravascular aggregates compatible with early microthrombotic changes. These findings support the concept that underassistance injury may extend beyond the lung parenchyma and respiratory muscles to involve cardiovascular and pulmonary microvascular domains.

Las anomalías congénitas del arco aórtico, como los anillos vasculares, son causas infrecuentes de obstrucción extrínseca de vía aérea central. Su diagnóstico es complejo debido a una presentación clínica inespecífica y superposición con patologías respiratorias frecuentes. Objetivo: Describir los hallazgos de la mecánica respiratoria que orientaron a la sospecha de una obstrucción fija de la vía aérea central secundaria a un anillo vascular en lactante críticamente enfermo. Caso Clínico: Lactante de 7 meses, gemelar monocigótico, previamente sano, ingresó por falla respiratoria aguda en el contexto de una infección viral respiratoria baja, requiriendo ventilación mecánica invasiva (VMI). Durante su evolución presentó episodios súbitos de hipoxemia, hipoventilación y aumento marcado de las presiones inspiratorias. El análisis detallado de la mecánica respiratoria evidenció un aumento significativo del componente resistivo inspiratorio y espiratorio, con incremento del gradiente entre presión inspiratoria pico (PIP) y presión meseta (PPLAT), asociado a un aumento de presión positiva al final de la espiración intrínseca (iPEEP). Estas mediciones cambiaban abruptamente al desplazar distalmente el tubo endotraqueal, lo que hizo sospechar de obstrucción fija de la vía aérea central. La angiografía tomográfica computada de tórax confirmó la presencia de un anillo vascular completo secundario a arco aórtico derecho con divertículo de Kommerell. Tras resolución del cuadro agudo, fue sometido a corrección quirúrgica sin complicaciones. Conclusiones: En lactantes con falla respiratoria aguda de evolución inhabitual, el análisis fisiopatológico de la mecánica respiratoria durante la VMI puede contribuir a la sospecha de obstrucción fija de la vía aérea central y orientar el estudio anatómico dirigido.

Strenuous respiratory effort has been proposed as a second hit, introducing the concepts of “patient self-inflicted lung injury” (P-SILI) and underassistance myotrauma. We investigated the effects of continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) on inspiratory and expiratory effort, lung injury, and myotrauma of obligatory and accessory respiratory muscles in experimental P-SILI. In rats, lung injury was induced through surfactant depletion, followed by 3 h of standard oxygen therapy (2 L/min, positive control) or supported ventilation (CPAP 6 cmH2O, HFNO 4 L/min, and protective mechanical ventilation [MV, negative control] groups). Subjects were assessed through esophageal manometry, surface electromyography on the abdominal wall, thoracic ultrasound, plasma multiplex analysis, and histology on the lungs, diaphragm, and accessory inspiratory and expiratory muscles. Compared against standard oxygen therapy, the MV and CPAP groups resulted in lower inspiratory and expiratory efforts and diaphragm excursion. Furthermore, intragroup analysis showed that CPAP also reduced respiratory rate and prevented the loss of lung aeration. All support therapies prevented lung, diaphragm, and accessory muscle injuries, but with nuances. In lungs and accessory muscles, MV showed the highest injury protection and HFNO the lowest, while CPAP was the most protective for the diaphragm. Only MV resulted in a lower plasma GRO-α concentration than standard oxygen therapy. Invasive and non-invasive respiratory support therapies are effective in protecting the lungs and respiratory muscles, but the effect is stepped in the lung and varies between obligatory and accessory respiratory muscles.

Abstract Background In preclinical studies, under-assisted respiratory effort has been identified as promoting lung injury, leading to the concept of “patient self-inflicted lung injury” (P-SILI). We aim to characterize this second hit at the ultrastructural level through scanning electron microscopy. Methods In rats, lung injury was induced through surfactant depletion, followed by 3h of standard oxygen therapy or protective mechanical ventilation (MV). The lungs were fixed and removed to be subsequently scanned using a field emission scanning electron microscope. Images were analyzed using a semi-quantitative approach, scoring ten random alveoli for wall discontinuities and hemorrhage, and five small pulmonary vessels for microthrombosis. Computer-assisted morphometric evaluations were performed to quantify loss of lung aeration. Results The standard oxygen therapy group showed higher frequencies of alveolar wall discontinuities, alveolar hemorrhage, and microthrombosis, compared to the MV group (all p < 0.05). The former also resulted in a lower aeration assessed by the aeration/tissue ratio. Conclusions Alveolar wall fractures suggest that unsupported spontaneous breathing induces stress failure in the lung parenchyma. The fractures were associated with hemorrhage and alveolar collapse, as well as with the formation of microthrombi in small pulmonary vessels. This can be caused by regional deformation phenomena as well as by cyclical lung vascular on–off flow.

Background: Respiratory syncytial virus (RSV) commonly causes severe lower respiratory tract disease. Adenovirus is detected less often, but severe pneumonia may occur. The pediatric intensive care unit (PICU) course associated with adenovirus detection compared with RSV-only detection is not well defined. Methods: We studied clinician-tested, virus-positive PICU admissions of children aged 1 month to 18 years from 37 PICUs in 7 Latin American countries (2017–2025). Children with RSV and/or adenovirus detection who used respiratory support were grouped as RSV-only, adenovirus-only or RSV-adenovirus codetection. The primary outcome was PICU death or worse functional status at discharge. Adjusted associations were estimated with logistic regression; Firth penalization was used for mortality. Results: Among 3196 PICU admissions, 2859 had RSV-only, 257 adenovirus-only and 80 codetection. PICU mortality was 12/257 (4.7%) in adenovirus-only, 13/2859 (0.5%) in RSV-only and 2/80 (2.5%) in codetection. Compared with RSV-only detection, adenovirus-only detection was associated with mortality [adjusted odds ratio (OR): 10.56; 95% confidence interval (CI): 4.57–24.43] and with PICU death or worse functional status at discharge [21/222 (9.5%) vs 45/2308 (1.9%); adjusted OR: 6.57; 95% CI: 3.59–12.03]. Among nonsurvivors, the median PICU day of death was 3 (IQR: 2–6) with adenovirus-only detection and 8 (IQR: 3–9) with RSV-only detection. Conclusions: In this multicenter Latin American PICU cohort, adenovirus-only detection was associated with a higher-risk acute course than RSV-only detection, including higher mortality and worse functional status at PICU discharge.

BACKGROUND:Respiratory syncytial virus (RSV) commonly causes severe lower respiratory tract disease. Adenovirus is detected less often, but severe pneumonia may occur. The pediatric intensive care unit (PICU) course associated with adenovirus detection compared with RSV-only detection is not well defined. METHODS:We studied clinician-tested, virus-positive PICU admissions of children aged 1 month to 18 years from 37 PICUs in 7 Latin American countries (2017-2025). Children with RSV and/or adenovirus detection who used respiratory support were grouped as RSV-only, adenovirus-only or RSV-adenovirus codetection. The primary outcome was PICU death or worse functional status at discharge. Adjusted associations were estimated with logistic regression; Firth penalization was used for mortality. RESULTS:Among 3196 PICU admissions, 2859 had RSV-only, 257 adenovirus-only and 80 codetection. PICU mortality was 12/257 (4.7%) in adenovirus-only, 13/2859 (0.5%) in RSV-only and 2/80 (2.5%) in codetection. Compared with RSV-only detection, adenovirus-only detection was associated with mortality [adjusted odds ratio (OR): 10.56; 95% confidence interval (CI): 4.57-24.43] and with PICU death or worse functional status at discharge [21/222 (9.5%) vs 45/2308 (1.9%); adjusted OR: 6.57; 95% CI: 3.59-12.03]. Among nonsurvivors, the median PICU day of death was 3 (IQR: 2-6) with adenovirus-only detection and 8 (IQR: 3-9) with RSV-only detection. CONCLUSIONS:In this multicenter Latin American PICU cohort, adenovirus-only detection was associated with a higher-risk acute course than RSV-only detection, including higher mortality and worse functional status at PICU discharge.

BACKGROUND:Data on the physiological impact of tracheal intubation and positive end-expiratory pressure (PEEP) on respiratory mechanics in anesthetized children are scarce. We aimed to evaluate the mechanical effects of intubation and PEEP in children without lung pathology under general anesthesia. METHODS:Prospective physiologic experimental crossover study, in children under 15 years scheduled for elective surgery. After anesthesia induction and neuromuscular blockade, volume-controlled ventilation was initiated. Respiratory mechanics were assessed before (mask ventilation) and after tracheal intubation, at PEEP 0 and 5 cmH₂O. Measured variables included peak inspiratory (PIP), plateau (PPLAT), and total expiratory pressures (tPEEP). Calculated parameters were compliance (Crs), driving pressure (ΔP), and mechanical power (MP). A mixed linear regression model was used. RESULTS:60 patients were included. Median age 58.0 (18.0-84.0) months. Intubation increased PIP-PPLAT + 23.9% (p < 0.001), Raw +16.4% (p = 0.011), and ΔP + 20.4% (p < 0.001); and decreased Crs -14% (p = 0.001). PEEP during mask ventilation reduced ΔP 29.1% (p < 0.001) and increased Crs 46.7% (p < 0.001). Combined intubation and PEEP reduced ΔP (-7.9%, p = 0.002) and increased Crs (+19.6%, p < 0.001). PEEP raised MP both during mask ventilation (+50%) and after intubation (+83.3%, both p < 0.001). Children under 2 years showed higher Raw than older children across all conditions (p < 0.001), but similar behavior in ΔP and Crs. CONCLUSION:PEEP and intubation induce changes in respiratory mechanics. While tracheal intubation increases PIP and ΔP, and decreases Crs, the addition of PEEP partially mitigates these effects on airway pressures, but not on MP. These results suggest a deterioration of both the resistive and elastic components during MV. TRIAL REGISTRATION:This project was registered and approved for implementation by the Pediatric Hospital Center Pereira Rossell Institutional Review Board and registered in the Ministry of Public Health (#7647719). Informed and signed consent was obtained from all the children's parents or responsible guardians. All procedures in this study were performed in accordance with the Declaration of Helsinki.

OBJECTIVE:This study aimed to identify early clinical predictors of non-invasive ventilation (NIV) failure in children with Pediatric Acute Respiratory Distress Syndrome (PARDS) and to develop a model to predict NIV outcomes. METHODS:A prospective observational study including children (0-15 years) who were supported by NIV and met PARDS criteria was performed in two public PICUs in Chile. Demographic, physiological variables, and clinical outcomes were recorded. Logistic regression was used to identify risk factors for NIV failure and develop a predictive model. RESULTS:Seventy-six patients were enrolled (median age 22 months [IQR 11-48]; weight 12.1 kg [9.6-18.3]). Eighteen patients (24%) failed NIV (Failure group), with a median NIV duration of 12.5 h (IQR 8-23.8). The Failure group showed a significant reduction in the SpO2/FiO2 ratio after 2 h of NIV (-59 [-124 to 5] vs -2 [-49 to 30], p = 0.03). In multivariate analysis, an increase in ΔSpO2/FiO2 (improvement in oxygenation) was associated with lower odds of NIV failure (OR 0.98; 95% CI 0.97-0.99; p = 0.006), indicating that worsening oxygenation was associated with a higher risk. The final prediction model included age and early changes in SpO2/FiO2, respiratory rate, and heart rate, demonstrating good discrimination (AUROC 0.764; 95% CI 0.641-0.888). CONCLUSION:In children with PARDS treated with NIV, a model including age and early changes in oxygenation, heart rate, and respiratory rate within the first 2 h predicts the need for intubation with good discrimination.

Surgery for severe scoliosis (SS) is usually performed in the prone position. Changes in respiratory mechanics related to position and positive end expiratory pressure (PEEP) titration during anesthesia of SS are understudied. We aimed to investigate the effect of prone position and PEEP on the respiratory mechanics of scoliotic children undergoing spine surgery. Prospective, crossover study performed in two pediatric hospitals (Montevideo, Uruguay-Centro Hospitalario Pereira Rossell- and Milano, Italy-Vittore Buzzi Children’s Hospital). Shortly after intubation, pulmonary mechanics measurements were performed using inspiratory and expiratory breath holds during volume-controlled ventilation with a set tidal volume (TV) of 8 ml/kg and a respiratory rate adjusted to maintain normocapnia. Measurements of peak (PIP), plateau (PPLAT) and total PEEP (tPEEP) were obtained at three levels of applied PEEP: 0 (ZEEP), 5, and 10 cmH2O both in supine (baseline) and prone positions. Driving pressure (∆P: PPLAT–tPEEP) was calculated to obtain static respiratory system compliance (Crs: TV/∆P). Crs and pressures were analyzed using a mixed linear regression model with a random subject effect in their relationship with position and PEEP. Sixty-nine patients were enrolled. Crs was negatively associated with Cobb angle in all the cohorts. Only in secondary scoliosis, it was positively associated with body mass index. Crs was also negatively correlated with the prone position and positively correlated with increasing PEEP levels. The interaction between PEEP and position was studied and showed no significance. Crs is influenced by the severity of scoliosis and the nutritional status during spine surgery. The addition of PEEP improves Crs and reduces ∆P in the supine position, but both worsen in the prone position. These changes can be related to the effects of position on chest wall compliance. Question: This study investigates the effect of prone position and the application of PEEP on respiratory mechanics in children undergoing spinal surgery for severe scoliosis. Findings: Respiratory system compliance was affected by the severity of scoliosis and the nutritional status, and it improved with application of PEEP, while decreased during prone position. Meaning: Application on low-moderate PEEP level during scoliosis surgery is useful to counteract atelectasis formation due to lung compression following the primary disease and diaphragm elevation during prone position.

The emergence of the concepts of patient self-inflicted lung injury and lung and diaphragm-protective ventilation has renewed interest in quantifying respiratory drive, respiratory effort, and work of breathing in real-time and at the bedside. Measurements derived from electromyography of respiratory muscles and esophageal manometry are the gold standard, but their current use in pediatric ICUs is scarce. There are other direct and indirect methods to quantify respiratory drive and effort that have been validated in critically ill pediatric patients. Direct methods have been adequately tested, specifically to customize the level of support provided from the acute phase to weaning from mechanical ventilation. Promising indirect methods may be the first step, and some of them have been adequately validated. Given the heterogeneity of the pediatric population and the scarcity of cut-off thresholds, decisions must be based on the trajectory of drive and effort, preferably using a multimodal approach. In this review, we summarize the current state of the art regarding direct methods and new tools for quantifying respiratory drive and effort, including their relevance and limitations in decision-making.

In patients with acute hypoxemic respiratory failure, spontaneous breathing efforts may contribute to patient self-inflicted lung injury through increased ventilation inhomogeneity and systemic inflammation. Whether early transition to controlled mechanical ventilation (CMV) mitigates these effects remains uncertain. This observational, prospective cohort study included 40 ICU patients with acute hypoxemic respiratory failure who initially breathed spontaneously. Based on clinical decisions, patients were managed with either continued spontaneous breathing (SB group, n = 12) or transitioned to CMV (CMV group, n = 28). Arterial blood gases, hemodynamics, plasma cytokines (IL-6 and IL-8), and ventilation distribution via electrical impedance tomography (EIT) were recorded at baseline and after 24 h. In the CMV group, intermediate time points (T2, T6, T12) were also assessed after intubation. The trial was registered in ClinicalTrials.gov (NCT03513809). In the CMV group, respiratory rate and heart rate decreased significantly over time. IL-6 levels dropped markedly from 305 ± 938 pg/mL at baseline to 27 ± 58 pg/mL at 24 h (p = 0.0195), accompanied by a significant improvement in oxygenation (PaO₂/FiO₂ from 140 ± 51 to 199 ± 67, p = 0.0004). EIT data showed improved ventilation distribution with increased end-expiratory lung impedance, decreased global inhomogeneity, and a shift in the center of ventilation toward dorsal regions. In contrast, the SB group showed no significant changes over 24 h in gas exchange, systemic inflammation, or EIT-derived parameters. In patients with acute hypoxemic respiratory failure initially breathing spontaneously, transition to CMV was associated with reduced IL-6 levels and improved ventilatory homogeneity over 24 h. These exploratory findings indicate that connection to controlled mechanical ventilation was associated with reduced systemic inflammation, a relationship that warrants confirmation in larger prospective studies.

Objective:This feasibility study aimed to describe the relation between ventricular dysfunction and outcome in pediatric sepsis. Methods:This prospective observational multicenter study was conducted in two Pediatric Intensive Care Units (PICU). We enrolled 51 patients aged younger than 15 year-old diagnosed with sepsis or septic shock. Functional echocardiography was performed by a pediatric intensivist within the first 24 h of admission and blind validated by a pediatric cardiologist. Ventricular dysfunction was defined by the presence of left or right systolic and/or diastolic dysfunction. The absence of these findings was considered normal ventricular function. Outcome was assessed by septic shock diagnosis rate, pediatric adaptation of Sequential Organ Failure Assessment (pSOFA), cardiovascular component of pSOFA, PICU-free and ventilator-free days. Results:29 patients had sepsis, and 22 had septic shock. The main sites of infection were pulmonary (58.8%) and abdominal (17.6%). One out of four had ventricular dysfunction, and this group presented higher frequency of septic shock (69.2% vs. 34.2%, p = 0.028), higher frequency of total pSOFA ≥3 at 24 h (92% vs. 64%, p = 0.04), cardiovascular component of pSOFA (69.2% vs. 31.2%, p = 0.017), and fewer PICU-free days [18 [0-23] vs. 23 [18-25], p = 0.027], compared to normal ventricular function group. Additionally, there were more abnormal tissue doppler measurements, lower ś wave Z-Score [-0.6 [-1.3;0.4] vs. 0.5 [-0.2;1.1], p = 0.01] and lower é wave Z-Score [1.5 [-2;0,1] vs. -0.3 [-2;0.4], p = 0.03] in the ventricular dysfunction group. Conclusion:Ventricular dysfunction was associated with more sepsis severity at 24 hours, fewer PICU-free days. Tissue doppler parameters were related to ventricular dysfunction.

Acute Respiratory Distress Syndrome (ARDS) is a leading cause of morbidity and mortality among critically ill patients, and mechanical ventilation (MV) plays a critical role in its management. One of the key parameters of MV is the level of positive end-expiratory pressure (PEEP), which helps to maintain an adequate lung functional volume. However, the optimal level of PEEP remains controversial. The classical approach in clinical trials for identifying the optimal PEEP has been to compare “high” and “low” levels in a dichotomous manner. High PEEP can improve lung compliance and significantly enhance oxygenation but has been inconclusive in hard clinical outcomes such as mortality and duration of MV. This discrepancy could be related to the fact that inappropriately high or low PEEP levels may adversely affect other organs, such as the heart, brain, and kidneys, which could counteract its potential beneficial effects on the lung. Patients with ARDS often develop acute kidney injury, which is an independent marker of mortality. Three primary mechanisms have been proposed to explain lung-kidney crosstalk during MV: gas exchange abnormalities, such as hypoxemia and hypercapnia; remote biotrauma; and hemodynamic changes, including reduced venous return and cardiac output. As PEEP levels increase, lung volume expands to a variable extent depending on mechanical response. This dynamic underlies two potential mechanisms that could impair venous return, potentially leading to splanchnic and renal congestion. First, increasing PEEP may enhance lung aeration, particularly in highly recruitable lungs, where previously collapsed alveoli reopen, increasing lung volume and pleural pressure, leading to vena cava compression, which can contribute to systemic venous congestion and abdominal organ impairment function. Second, in lungs with low recruitability, PEEP elevation may induce minimal changes in lung volume while increasing airway pressure, resulting in alveolar overdistension, vascular compression, and increased pulmonary vascular resistance. Therefore, we propose that high PEEP settings can contribute to renal congestion, potentially impairing renal function. This review underscores the need for further rigorous research to validate these perspectives and explore strategies for optimizing PEEP settings while minimizing adverse renal effects.

OBJECTIVE:To evaluate the ability of the criteria "At-risk for PARDS" to identify patients with acute respiratory infection hospitalized outside the pediatric intensive care unit (PICU) who are at high risk of developing pediatric acute respiratory distress syndrome (PARDS) and describe the timing for the identification. The secondary aim was to explore clinical outcome differences between patients with and without risk for PARDS. METHODS:We conducted an observational prospective cohort study from June to August 2019. Children under 15 years old hospitalized in a pediatric ward due to an acute respiratory tract infection were included. MAIN RESULTS:A total of 177 patients with a median age of 12 (IQR 5; 25) months were included. Registered data included demographics, respiratory support, at-risk for PARDS and PARDS diagnosis according to PALICC consensus. PICU admission, hospital length of stay (LOS) and intrahospital mortality were the outcomes compared between children with and without risk for PARDS. The at-risk criteria, within 48 h of admission, showed an overall accuracy, sensitivity, and specificity of 82.5%, 100%, and 81.9% respectively, to detect patients that progress to PARDS. The at-risk for PARDS criteria was met in 37 cases (20.9%), which also were more likely to developed PARDS (6/37 [16.2%] vs. 0/140 [0%]; p < 0.001), had higher admission to PICU (16/37 [43.2%] vs. 0 [0%]; p < 0.001) and hospital LOS (7 [6; 12] days vs. 5 [3-6] days; p < 0.001), compared with the group without at-risk for PARDS. CONCLUSIONS:The at-risk for PARDS criteria within 48 h of admission demonstrated an adequate ability to identify patients with a respiratory infection at increased risk of developing PARDS. Patients who met the at-risk for PARDS criteria before PICU admission presented with unfavorable clinical outcomes compared with those without risk.

Strenuous respiratory effort has been proposed as a second hit in severe acute lung injury (ALI), introducing the concept of “patient self-inflicted lung injury” (P-SILI). In an experimental setting, noninvasive continuous positive airway pressure (CPAP) attenuates lung and diaphragmatic injury, but the underlying mechanisms remains elusive. Here we investigate the effects of noninvasive CPAP on global and regional lung strain and diaphragm velocity of contraction and relaxation in an experimental P-SILI model. Lung injury was induced in Sprague Dawley rats through surfactant depletion followed by either three hours of standard oxygen therapy (Control group) or CPAP support (CPAP group). Subjects were assessed through inspiratory and expiratory muscle activation. Regional lung and diaphragmatic deformation amplitude (strain) and the rate of change (strain rate) maps were developed using a micro-computed tomography (µCT) scan. Morphometric tissue assessment was carried out to study biological damage. Compared with the Control group, the CPAP group resulted in: (1) higher SpO2 and lower respiratory rate, nasal flaring, inspiratory and expiratory muscle activation, and minute ventilation at the end of the study; (2) lower global and regional tidal ventilation at the beginning of the study; (3) lower regional inspiratory and expiratory lung strain rate over time; and (4) higher muscle area in the diaphragm morphometric analysis. Furthermore, intragroup analysis showed that only the CPAP group reduced the inspiratory and expiratory muscle activation, the global and regional expiratory lung strain rate and the regional velocity of relaxation of the diaphragm over time. Standard oxygen therapy resulted in worse patterns of lung strain rate and diaphragm velocity of relaxation, consistent with P-SILI and load-induced diaphragm injury. CPAP resulted in improved lung function, decreased lung strain rate, and diaphragmatic relaxation velocity throughout the respiratory cycle. We conclude that CPAP promotes biomechanical protection in injured lungs and diaphragm, more noticeably during the expiratory phase.

Abstract Background The spatiotemporal progression and patterns of tissue deformation in ventilator-induced lung injury (VILI) remain understudied. Our aim was to identify lung clusters based on their regional mechanical behavior over space and time in lungs subjected to VILI using machine-learning techniques. Results Ten anesthetized pigs (27 ± 2 kg) were studied. Eight subjects were analyzed. End-inspiratory and end-expiratory lung computed tomography scans were performed at the beginning and after 12 h of one-hit VILI model. Regional image-based biomechanical analysis was used to determine end-expiratory aeration, tidal recruitment, and volumetric strain for both early and late stages. Clustering analysis was performed using principal component analysis and K-Means algorithms. We identified three different clusters of lung tissue: Stable, Recruitable Unstable, and Non-Recruitable Unstable. End-expiratory aeration, tidal recruitment, and volumetric strain were significantly different between clusters at early stage. At late stage, we found a step loss of end-expiratory aeration among clusters, lowest in Stable, followed by Unstable Recruitable, and highest in the Unstable Non-Recruitable cluster. Volumetric strain remaining unchanged in the Stable cluster, with slight increases in the Recruitable cluster, and strong reduction in the Unstable Non-Recruitable cluster. Conclusions VILI is a regional and dynamic phenomenon. Using unbiased machine-learning techniques we can identify the coexistence of three functional lung tissue compartments with different spatiotemporal regional biomechanical behavior.

Identificar los factores asociados con la ventilación mecánica prolongada (pVMI) en pacientes pediátricos en la unidad de cuidados intensivos pediátricos (UCIP). Análisis secundario de una cohorte prospectiva. UCIP en los centros que integran LARed Network entre abril del 2017 y enero del 2022. Pacientes pediátricos en ventilación mecánica (VMI) debido a causas respiratorias. Definimos pVMI como eventos con tiempo VMI mayor al percentil 75 global. Ninguna. Datos demográficos, diagnósticos, puntajes de gravedad, terapias, complicaciones, estancias y morbimortalidad. Se incluyó a 1.698 niños con VMI de 8 ± 7 días y se definió pVMI en 9 días. Los factores relacionados al ingreso fueron la edad menor de 6 meses (OR 1,61, IC del 95%, 1,17-2,22), la displasia broncopulmonar (OR 3,71, IC del 95%, 1,87-7,36) y las infecciones fúngicas (OR 6,66, IC del 95%, 1,87-23,74), mientras que los pacientes con asma tuvieron menor riesgo de pVMI (OR 0,30, IC del 95%, 0,12-0,78). En cuanto a la evolución y la estancia en UCIP, se relacionó a neumonía asociada a la ventilación mecánica (OR 4,27, IC del 95%, 1,79-10,20), necesidad de traqueostomía (OR 2,91, IC del 95%, 1,89-4,48), transfusiones (OR 2,94, IC del 95%, 2,18-3,96), bloqueo neuromuscular (OR 2,08, IC del 95%, 1,48-2,93) y ventilación de alta frecuencia (OR 2,91, IC del 95%, 1,89-4,48) y una mayor estadía en UCIP (OR 1,13, IC del 95%, 1,10-1,16). Además, la presión media aérea mayor a 13 cmH2O se asoció a pVMI (OR 1,57, IC del 95%, 1,12-2,21). Se identificaron factores relacionados con VMI de duración mayor a 9 días en pacientes pediátricos en UCIP en cuanto a ingreso, evolución y estancia. To identify factors associated with prolonged mechanical ventilation (pMV) in pediatric patients in pediatric intensive care units (PICUs). Secondary analysis of a prospective cohort. PICUs in centers that are part of the LARed Network between April 2017 and January 2022. Pediatric patients on mechanical ventilation (IMV) due to respiratory causes. We defined IMV time greater than the 75th percentile of the global cohort. None. Demographic data, diagnoses, severity scores, therapies, complications, length of stay, morbidity, and mortality. One thousand 6 hundred and ninety 8 children with MV of 8 ± 7 days were included, and pIMV was defined as 9 days. Factors related to admission were age under 6 months (OR 1.61, 95% CI 1.17–2.22), bronchopulmonary dysplasia (OR 3.71, 95% CI 1.87–7.36), and fungal infections (OR 6.66, 95% CI 1.87–23.74), while patients with asthma had a lower risk of pIMV (OR 0.30, 95% CI 0.12–0.78). Regarding evolution and length of stay in the PICU, it was related to ventilation-associated pneumonia (OR 4.27, 95% CI 1.79–10.20), need for tracheostomy (OR 2.91, 95% CI 1.89–4.48), transfusions (OR 2.94, 95% CI 2.18–3.96), neuromuscular blockade (OR 2.08, 95% CI 1.48–2.93), high-frequency ventilation (OR 2.91, 95% CI 1.89–4.48), and longer PICU stay (OR 1.13, 95% CI 1.10–1.16). In addition, mean airway pressure greater than 13 cmH2O was associated with pIMV (OR 1.57, 95% CI 1.12–2.21). Factors related to IMV duration greater than 9 days in pediatric patients in PICUs were identified in terms of admission, evolution, and length of stay.

Objectives: To identify factors associated with prolonged mechanical ventilation (pMV) in pediatric patients in pediatric intensive care units (PICUs). Design: Secondary analysis of a prospective cohort. Setting: PICUs in centers that are part of the LARed Network between April 2017 and January 2022. Participants: Pediatric patients on mechanical ventilation (IMV) due to respiratory causes. We defined IMV time greater than the 75th percentile of the global cohort. Interventions: None. Main variables of interest: Demographic data, diagnoses, severity scores, therapies, complications, length of stay, morbidity, and mortality. Results: One thousand 6 hundred and ninety 8 children with MV of 8 +/- 7 days were included, and pIMV was defined as 9 days. Factors related to admission were age under 6 months (OR 1.61, 95% CI 1.17-2.22), bronchopulmonary dysplasia (OR 3.71, 95% CI 1.87-7.36), and fungal infections (OR 6.66, 95% CI 1.87--23.74), while patients with asthma had a lower risk of pIMV (OR 0.30, 95% CI 0.12-0.78). Regarding evolution and length of stay in the PICU, it was related to ventilationassociated pneumonia (OR 4.27, 95% CI 1.79-10.20), need for tracheostomy (OR 2.91, 95% CI 1.89-4.48), transfusions (OR 2.94, 95% CI 2.18-3.96), neuromuscular blockade (OR 2.08, 95% CI 1.48-2.93), high -frequency ventilation (OR 2.91, 95% CI 1.89-4.48), and longer PICU stay (OR 1.13, 95% CI 1.10-1.16). In addition, mean airway pressure greater than 13 cmH2O was associated with pIMV (OR 1.57, 95% CI 1.12-2.21). Conclusions: Factors related to IMV duration greater than 9 days in pediatric patients in PICUs were identified in terms of admission, evolution, and length of stay. (c) 2023 Elsevier Espana, S.L.U. y SEMICYUC. All rights reserved.