Mean Airway Pressure Research Articles

Impact of different weaning strategies of high-frequency ventilation (HFV) on neonatal cerebral oxygen saturation and hemodynamics: protocol for a prospective randomized controlled trial.

High-frequency ventilation (HFV) is commonly used in neonatal intensive care units to provide respiratory support for critically ill neonates. Currently, there is no standardized procedure for weaning from HFV. Two commonly used strategies are transitioning from HFV to conventional mechanical ventilation (CMV) before extubation (HFV-CMV) and extubation after decreasing mean airway pressure during HFV (HFV-HFV). The impact of these strategies on neonatal cerebral oxygenation and hemodynamics remains incompletely understood. We will conduct a prospective, single-center, randomized controlled trial to investigate the effects of two different HFV weaning strategies (HFV-CMV, HFV-HFV) on neonatal cerebral oxygenation and hemodynamics. The patients enrolled in the trial will be randomly allocated to either the HFV-CMV group or the HFV-HFV group in a 1:1 ratio. The primary outcome will be cerebral oxygen saturation (ScO2) before and after the intervention. Second outcomes are cerebral fractional tissue oxygen extraction, heart rate, blood pressure, and the incidence and severity of intraventricular hemorrhage and periventricular leukomalacia. We hypothesize that HFV-CMV results in positive impact on neonatal cerebral oxygenation compared to HFV-HFV. This study aims to identify a better weaning strategy for HFV and contribute evidence-based data to enhance its clinical application in newborns, potentially improving the care and outcomes for neonates receiving HFV. This study aims to assessing the impact of different HFV weaning strategies on neonatal cerebral oxygenation and hemodynamics, as well as the relationship between the duration of HFV under different strategies and neurological complications, to identify better weaning methods for HFV. We hope to contribute evidence-based data to enhance clinical application of HFV in newborns, potentially improving the care and outcomes for neonates receiving HFV. Chinese Clinical Trial Registry: ChiCTR2400088628. Registered on August 22, 2024, https://www.chictr.org.cn/bin/project/edit?pid=235926 .

Effect of high-frequency oscillatory ventilation with intermittent sigh breaths on carbon dioxide levels in neonates.

High-frequency oscillatory ventilation (HFOV) minimizes ventilator-induced lung injuries. Spontaneous sigh breathing may augment the functional residual capacity, increase lung compliance, and recruit atelectatic alveoli. To evaluate the difference in the partial pressure of carbon dioxide (PaCO2) in neonates receiving invasive HFOV as the primary mode of respiratory support before versus after sigh breaths (Sighs). This prospective study was conducted between January and December 2023. Intubated preterm and term neonates who underwent HFOV with an available arterial line were enrolled in this study after informed parental consent was obtained. Sighs were set at a frequency of 3 breaths/min and pressure of 5 cm H2O above the mean airway pressure for 2 hours. Arterial blood gas was collected before and after Sighs and analyzed using two dependent tests. Thirty neonates with a mean gestational age of 33.6±4.1 weeks and median date of intervention of 1.88 (interquartile range, 0.87-3.79) days were enrolled. The mean PaCO2 level was significantly lower in the HFOV with Sighs group (45.2±6.6 mm Hg) versus the HFOV alone group (48.8±3.1 mm Hg) with a mean difference (MD) of -3.6 mm Hg (95% confidence interval [CI], -6.3 to -0.9; P=0.01). Subgroup analyses indicated the ability of Sighs to reduce the PaCO2 level in neonates with respiratory distress syndrome (n=15; MD [95% CI] = -4.2 [-8.2 to -0.2] mm Hg; P=0.04).

Abstract 4135318: Comparison of Right Ventricular Function Changes Between Volume Control and Pressure Support Ventilation Modes: A Prospective Study Using S' Prime Values

Background: This study assesses changes in right ventricular function by measuring S' values during the transition from volume control-assist control (VC-AC) to pressure support ventilation (PSV). Transitioning from VC-AC to PSV reduces the mean airway pressure (P mean) which causes a decrease in right ventricular afterload and also potentially improves venous return and right ventricular preload. PSV allows spontaneous breathing efforts, possibly increasing cardiac output. Thus, we expect a consistent increase in S' value when changing ventilator modes. Methods: This prospective observational study included ICU patients on invasive mechanical ventilation for over 24 hours. The clinical team decided when to switch from VC-AC to PSV. An average of three S' measurements was taken during VC-AC and within 10 minutes of transitioning to PSV. Sedation, vasopressor use, and Richmond Agitation-Sedation Scale scores were consistent throughout the measurements. The study was approved by the Albert Einstein College of Medicine IRB (#2023-15068) Results: Seventeen patients were included in the study, with an average age of 61.29 years (SD 11.39). Of these, 6 (35.3%) were female. The mean S' during VC-AC was 12.79 ± 4.52, and upon transitioning to PSV, it was 14.56 ± 3.89 (p-value 0.47). The intra-observer variability for S' was 5.3%. Of the seventeen patients, 5/17 (29%) showed an S' change of less than 5.3% and were deemed to have no significant variation; 7/17 (41%) experienced a significant decrease in S' (15.41% ± 7.29% SD), while the remaining 5/17 (29%) showed a significant increase (19.31 ± 13.23%). Conclusion: Our study demonstrates that transitioning from VC-AC to PSV results in variable changes in right ventricular systolic function, as indicated by S' values. Contrary to our expectations of a consistent increase, the interplay between S' values and ventilator mode changes appears to be non-linear, suggesting other factors may influence cardiopulmonary interactions in spontaneously breathing ventilated patients. These findings highlight the complexity of these interactions, underscoring the need for individualized patient management and paving the way for further research with a larger cohort.

Design and Implementation of a Computer-Controlled Hybrid Oscillatory Ventilator.

During mechanical ventilation, lung function and gas exchange in structurally heterogeneous lungs may be improved when volume oscillations at the airway opening are applied at multiple frequencies simultaneously, a technique referred to as multifrequency oscillatory ventilation (MFOV). This is in contrast to conventional high-frequency oscillatory ventilation (HFOV), for which oscillatory volumes are applied at a single frequency. In the present study, as a means of fully realizing the potential of MFOV, we designed and tested a computer-controlled hybrid oscillatory ventilator capable of generating the flows, tidal volumes, and airway pressures required for MFOV, HFOV, conventional mechanical ventilation (CMV), as well as oscillometric measurements of respiratory impedance. The device employs an iterative spectral feedback controller to generate a wide range of oscillatory waveforms. The performance of the device meets that of commercial mechanical ventilators in volume-controlled mode. Oscillatory modes of ventilation also meet design specifications in a mechanical test lung, over frequencies from 4 to 20 Hz and mean airway pressure from 5 to 30 cmH2O. In proof-of-concept experiments, the oscillatory ventilator maintained adequate gas exchange in a porcine model of acute lung injury, using combinations of conventional and oscillatory ventilation modalities. In summary, our novel device is capable of generating a wide range of conventional and oscillatory ventilation waveforms with potential to enhance gas exchange, while simultaneously providing less injurious ventilation.

A self-regulated expiratory flow device for mechanical ventilation: a bench study

IntroductionUnregulated expiratory flow may contribute to ventilator-induced lung injury. The amount of energy dissipated into the lungs with tidal mechanical ventilation may be used to quantify potentially injurious ventilation. Previously reported devices for variable expiratory flow regulation (FLEX) require, either computer-controlled feedback, or an initial expiratory flow trigger. In this bench study we present a novel passive expiratory flow regulation device.MethodsThe device was tested using a commercially available mechanical ventilator with a range of settings (tidal volume 420 ml and 630 ml, max. inspiratory flow rate 30 L/min and 50 L/min, respiratory rate 10 min−1, positive end-expiratory pressure 5 cmH2O), and a test lung with six different combinations of compliance and resistance settings. The effectiveness of the device was evaluated for reduction in peak expiratory flow, expiratory time, mean airway pressure, and the reduction of tidal dissipated energy (measured as the area within the airway pressure–volume loop).ResultsMaximal and minimal reduction in peak expiratory flow was from 97.18 ± 0.41 L/min to 25.82 ± 0.07 L/min (p < 0.001), and from 44.11 ± 0.42 L/min to 26.30 ± 0.06 L/min, respectively. Maximal prolongation in expiratory time was recorded from 1.53 ± 0.06 s to 3.64 ± 0.21 s (p < 0.001). As a result of the extended expiration, the maximal decrease in I:E ratio was from 1:1.15 ± 0.03 to 1:2.45 ± 0.01 (p < 0.001). The greatest increase in mean airway pressure was from 10.04 ± 0.03 cmH2O to 17.33 ± 0.03 cmH2O. Dissipated energy was significantly reduced with the device under all test conditions (p < 0.001). The greatest reduction in dissipated energy was from 1.74 ± 0.00 J to 0.84 ± 0.00 J per breath. The least reduction in dissipated energy was from 0.30 ± 0.00 J to 0.16 ± 0.00 J per breath. The greatest and least percentage reduction in dissipated energy was 68% and 33%, respectively.ConclusionsThe device bench tested in this study demonstrated a significant reduction in peak expiratory flow rate and dissipated energy, compared to ventilation with unregulated expiratory flow. Application of the device warrants further experimental and clinical evaluation.

Application value of opioid-free anesthesia in renal cyst decompression by laparoscopy.

The objective of the study was to analyze the application value of opioid-free anesthesia (OFA) in renal cyst decompression by laparoscopy. A total of 124 patients undergoing renal cyst decompression by laparoscopy in our hospital were selected and divided into opioid anesthesia (OA) and OFA groups (n = 62). Fentanyl and remifentanil were used for anesthesia induction in the OA group, while lidocaine and dexmedetomidine were employed for anesthesia induction in the OFA group. The homeostasis indicators (cortisol [Cor], adrenocorticotropic hormone [ACTH], C-reactive protein [CRP], and interleukin-6 [IL-6]) were also compared 10 min before anesthesia (Ta), at the end of operation (Tb), and 24 h after operation (Tc). At T1-T3, heart rate, mean arterial pressure, mean airway pressure, and partial pressure of end-tidal carbon dioxide were all lower in OFA group than those in OA group (p < 0.05). At Tb-Tc, the levels of Cor, ACTH, CRP, and IL-6 were all higher in both groups than those at Ta (p < 0.05), while they were lower in OFA group than those in OA group (p < 0.05). OFA is more beneficial to the respiratory and circulatory system and homeostasis of patients, and has higher anesthetic safety.

Inhaled Argon Dilates Pulmonary Vasculature in Rat Isolated Lungs.

During cardiopulmonary resuscitation, pulmonary vasoconstriction due to hypoxia and hypercarbia restricts blood flow from the right to the left heart, resulting in reduced cardiac output that further inhibits adequate oxygenation and the ability to distribute oxygenated blood and medications. An inhaled pulmonary vasodilator could attenuate vasoconstriction and, therefore, increase cardiac output. We used rat isolated lungs to test if inhaled Argon leads to pulmonary vasodilation in phenylephrine-treated lungs. Lungs of 13 adult male Sprague Dawley rats were isolated, ventilated, and perfused. Pulmonary artery and left atrium were cannulated and lungs perfused at constant flow with 4% albumin physiological saline solution. Controls (n=6) were ventilated with 65% N2, 5% CO2, 30% O2 and Argon lungs (n=7) with 65% Argon, 5% CO2, 30% O2. Pulmonary mean arterial pressure (pMAP) and airway pressure (AWP) were recorded continuously, and pulmonary vascular resistance (PVR) was calculated. Following baseline readings, phenylephrine, a pulmonary vasoconstrictor, was perfused at increasing concentrations from 10-7 M to 10-3 M every 5 min. Statistics: Student's t-Test, α=0.05. Argon led to significantly lower pMAPs and PVRs, independent of AWP. Thus, it significantly dilated pre-constricted pulmonary vessels in an ex-vivo lung model. When given during resuscitation, this might aid to increase cardiac output.

Validity of a new weaning index of discontinuation from mechanical ventilation in intensive care unit

Background Failure to wean from mechanical ventilation (MV) is a frequent problem in the intensive care unit (ICU) setting. Herein, we investigate a new WI measured at the initial spontaneous breathing trial (SBT) in order to predict successful liberation from MV in mechanically ventilated ICU cases. Patients and methods This prospective cross-sectional study consisted of two phases; Phase I was designed to create a new WI from the criteria of 60 mechanically ventilated patients, while Phase II aimed to assess the accuracy of that index in another 40 patients. Results The incidence of failed weaning was 33.3% in phase I, and 35% in phase II. Multivariate regression analysis was done for phase I variables, and the following equation was created; (((Cough strength×0.743)–1.927)×0.05+((PaCO2 (mmHg)×-0.126)+6.786)×0.08+((mean airway pressure (CmH2O)×-1.304)+14.119)×0.193+((PaO2/FIO2 × 0.268)-58.555)×0.328+((rapid shallow breathing index×-0.485)+24.406)×0.353). Using a cut-off value of &gt;0.69 and Applying this index in phase II, it showed a mean value of -1.43 and 4.67 in the failure and success groups, respectively (P&lt;0.001). This new WI with cut-off value (&gt;0.69) had 88.5% sensitivity, 57.1% specificity, and a 77.5% accuracy to predict the success of weaning from MV. Conclusion We developed a new WI using formula including (semiquantitative Cough strength, PCO2 gradient mean airway pressure, PO2/FIO2 ratio, Rapid shallow breathing index) with accepted sensitivity and moderate specificity for predicting successful weaning from MV in ICU patients. Its use should be encouraged in the ICU setting, especially by less experienced ICU physicians.

The Effect of Lactic Acidosis on Neonatal Outcomes in Premature Infants

The aim of the study was to evaluate neonatal outcomes in preterm infants.Materials and methods. The study included 58 premature neonates divided into 2 groups: «A» (N=34) with an adverse neonatal period ending in death and «B» (N=24) who survived. Clinical assessment of the infant, measurement of blood gases, acid-base balance (ABB) and lactate, recording of lung ventilation parameters, calculation of mean airway pressure, oxygenation index (OI) and ventilation efficiency index (VEI), neurosonography and, in case of death, pathological and histological examination of the brain were performed.Results. Elevated lactate was found in 24 patients (70.5%) in group A and in 12 patients (50%) in group B. The mean lactate levels in groups A and B were 8.1±3.3 and 6.3±2.8 mmol/L, respectively. In group A, 19 (55.9%) infants had severe acidosis, corresponding to a pH of 7.19 to 6.80. In group B, only 8 (33.3%) infants had a pH between 7.0 and 7.19. At birth, neonates in both groups were found to have a base deficit (BD), which was significantly lower in group A than in group B (P=0.004). There were no trends toward reduction of acidosis or normalization of ABB in infants in group A. Plasma BE levels in group B had returned to normal by 96 hours postpartum. The frequency of grade II, III peri/intraventricular hemorrhage (PIVH) and hemorrhage of other localization in group A were 8 (23.5%), 9 (26.5%), and 3 (8.8%), respectively. In group B, grade I PIVH and hemorrhage of other localization occurred in 5 (20.8%) and 1 (4.2%) cases, respectively. In neonates with grade II PIVH, severe lactic acidosis was diagnosed at birth: venous blood pH was 6.97 [6.8; 7.22], BE was (–21.6) [–30; –7.2] mmol/L, lactate level was 8.5 [6.3; 12.9] mmol/L, and pO₂ was 50.5 [20.5; 64] mm Hg. In infants with grade III PIVH, pH was –7.26 [7.12; 7.28], BE was (–8.1) [–8.9; –7] mmol/L, lactate was 7.6 [4.8; 8.9] mmol/L, and pO₂ was 33 [30; 50] mm Hg. Cell damage of varying severity affected all brain structures, as evidenced by absence or deformation of nuclei and nucleoli, and peripheral chromatin condensation. Morphological immaturity of brain structures was another negative factor.Conclusion. Lactic acidosis diagnosed at birth in premature infants is one of the indicators of perinatal hypoxia severity. Critical pH, BE, and lactate levels, as well as lack of response to treatment, contribute to structural brain damage and worsen prognosis. Severe changes in oxygen and lactate levels that persist for two days after birth lead to severe PIVH and irreversible brain changes.

Comparison of Nebulized Glycopyrronium with a Combination of Salbutamol and Ipratropium on Ventilatory Parameters in Critically Ill Mechanically Ventilated Patients of Chronic Obstructive Pulmonary Disease: An Observational Study.

The present study examined the duration of bronchodilation induced by nebulized glycopyrronium bromide (GB) and compared its effectiveness and incidence of any side effects with the combination of salbutamol and ipratropium bromide (SI) in critically ill mechanically ventilated chronic obstructive pulmonary disease (COPD) patients. This prospective, observational study was conducted in mechanically ventilated adult patients of COPD (18-75 years). Data of two groups of patients were collected for 12 hours each for three consecutive days after the nebulization - Group I: those who received 25 µg of GB, and Group II: those who received 1.25 mg of levo-salbutamol and 500 µg of ipratropium by nebulization. A significantly higher number of patients in group II had copious secretions. The mean static compliance was comparable at all time intervals, whereas the mean airway pressure was significantly lower in group II from 15 minutes to 4 hours post-nebulization. In group I, the onset of bronchodilation was 30 minutes on days 1 and 3, and 60 minutes on day 2, whereas, in group II, it was 60 minutes on days 1 and 2 and 30 minutes on day 3. In group I, bronchodilation was 10 hours on day 1 and 12 hours each on days 2 and 3, whereas in group II, bronchodilation was 4 hours on day 1 and 6 hours each on day 2 and 3. Compared with SI, GB nebulization resulted in lesser respiratory secretions, a longer duration of action in terms of lowered airway resistance, and no adverse effects like hypertension, tachycardia, or desiccation of respiratory secretions. Priya P, Nath SS, Kumar V, Kumar S. Comparison of Nebulized Glycopyrronium with a Combination of Salbutamol and Ipratropium on Ventilatory Parameters in Critically Ill Mechanically Ventilated Patients of Chronic Obstructive Pulmonary Disease: An Observational Study. Indian J Crit Care Med 2024;28(10):963-969.

Oxygenation Index, Oxygen Saturation Index vs PaO2/FiO2 *PEEP: A Secondary Analysis of OXIVA-CARDS Study.

The classification of Berlin definition is based on the PaO2/FiO2 ratio, which has been found to have a poor association with mortality. Airway pressures reflect lung compliance and the settings of mechanical ventilators. In this study, we aimed to investigate the change in the severity of COVID-19-associated acute respiratory distress syndrome (ARDS) classification using [PaO2/FiO2 × PEEP] (P/FP) ratio compared to the traditional P/F ratio, and whether the P/FP ratio improves the predictive validity of in-hospital mortality. Our study sample included patients from the OXIVA-CARDS study. In this secondary analysis, we examined the oxygenation index and oxygen saturation index in relation to the P/FP ratio, as well as the risk of P/FP in mortality. We used Pearson's correlation to assess the relationships between various parameters. Receiver operating characteristic analysis with Youden's index was used to compare the prognostic value of the oxygenation index (OI), oxygen saturation index (OSI), P/F ratio, P/FP ratio, and SaO2/FiO2 ratio for predicting overall mortality. Multiple logistic regression was also performed to determine the impact of mean airway pressure (Pmean), S/F ratio, OI, and P/FP ratio on mortality. A total of 201 patients (with 1543 measurements) were included in the analysis. Overall, 522 (34%) were reclassified into either more or less severe categories. Patients who were classified as having severe ARDS based on the P/FP ratio had significantly lower P/FP ratio, oxygenation index, and A-a O2 gradient as compared to those classified as having severe ARDS based on the P/F ratio (p < 0.05) at all levels of ARDS severity. On multivariate regression analysis, only the OI significantly impacted mortality (p < 0.05). We observed that the oxygen index and oxygen saturation index were more sensitive than the PaO2/FiO2 ratio and P/FP ratio. Additionally, only the oxygenation index had a significant impact on mortality. By including airway pressures in the calculation of the OI, its predictive ability is enhanced compared to using the S/F ratio, P/F ratio, or P/FP ratio. The sensitivity of mortality by including Pmean is higher as compared to when only PEEP is taken into consideration. P/FP is a weak predictor of mortality as compared to OI and OSI. Vadi SMR, Sanwalka N, Suthar D. Oxygenation Index, Oxygen Saturation Index vs PaO2/FiO2 *PEEP: A Secondary Analysis of OXIVA-CARDS Study. Indian J Crit Care Med 2024;28(10):917-922.

Neurally adjusted ventilatory assist (NAVA) in neonatal and pediatric critical care-A scoping review of randomized controlled trials.

We Aimed to analyze for which indications neurally adjusted ventilatory assist (NAVA) has been studied in pediatric patients by conducting a scoping review. PubMed, Scopus, and Web of Science databases were searched in September 2023. We included all randomized trials (including crossover, parallel, and cluster) comparing NAVA to other invasive ventilation modalities in children aged <18 years. We had three key outcomes. What have been the patient and disease groups where NAVA has been studied? What kind of trials and what has been the risk of bias in these randomized trials? What have been the most used outcomes and main findings? The risk of bias was assessed according to the risk of bias 2.0 tool. This review has been reported as preferred in PRISMA-ScR guidelines. After screening 367 abstracts, 27 full reports were assessed and finally 13 studies were included. Six studies were conducted in neonates and seven in older pediatric patients. Ten of the studies were crossover and three were parallel randomized. Overall risk of bias was low in two studies, had some concerns in six studies, and was high in five studies. Most issues came from the randomization process and bias in the selection of reported results. Most used outcomes were changes in clinical parameters or measurements (such as ventilation peak and mean airway pressures, oxygenation index), and ventilator synchrony. Three parallel group trials focused on ventilation duration. The majority of the studies found NAVA as a possible alternative ventilation strategy. Although NAVA is a widely used strategy in neonatal and pediatric intensive care the current literature has notable limitations due to the risk of bias in the original studies and lack of parallel studies focusing on clinical or cost-effectiveness outcomes.

Transpulmonary Pressure-Guided Mechanical Ventilation in Severe Acute Respiratory Distress Syndrome in PICU: Single-Center Retrospective Study in North India, 2018–2021

Objectives: In this study, we have reviewed the association between esophageal pressure-guided positive end-expiratory pressure (PEEP) setting and oxygenation and lung mechanics with a conventional mechanical ventilation (MV) strategy in patient with moderate to severe pediatric acute respiratory distress syndrome (PARDS). Design: Retrospective cohort, 2018–2021. Setting: Tertiary PICU. Patients: Moderate to severe PARDS patients who required MV with PEEP of greater than or equal to 8 cm H2O. Interventions: Esophageal pressure (i.e., transpulmonary pressure [PTP]) guided MV vs. not. Measurements and Main Results: We identified 26 PARDS cases who were divided into those who had been managed with PTP-guided MV (PTP group) and those managed with conventional ventilation strategy (non-PTP). Oxygenation and lung mechanics were compared between groups at baseline (0 hr) and 24, 48, and 72 hours of MV. There were 13 patients in each group in the first 24 hours. At 48 and 72 hours, there were 11 in PTP group and 12 in non-PTP group. On comparing these groups, first, use of PTP monitoring was associated with higher median (interquartile range) mean airway pressure at 24 hours (18 hr [18–20 hr] vs. 15 hr [13–18 hr]; p = 0.01) and 48 hours (19 hr [17–19 hr] vs. 15 hr [13–17 hr]; p = 0.01). Second, use of PTP was associated with higher PEEP at 24, 48, and 72 hours (all p &lt; 0.05). Third, use of PTP was associated with lower Fio 2 and greater Pao 2 to Fio 2 ratio at 72 hours. Last, there were 18 of 26 survivors, and we failed to identify an association between use of PTP monitoring and survival. Conclusions: In this cohort of moderate to severe PARDS cases undergoing MV with PEEP greater than or equal to 8 cm H2O, we have identified some favorable associations of oxygenation status when PTP-guided MV was used vs. not. Larger studies are required.

Nebulized Budesonide Prevents Airway Inflammation in Children with High Total IgE Levels After Open Heart Surgery with Cardiopulmonary Bypass: A Prospective Randomized Controlled Trial.

Cardiopulmonary bypass (CPB) is a crucial technique used to repair congenital heart defects (CHD); however, it may induce inflammatory response, leading to airway inflammation and need for prolonged mechanical ventilation. In this study, we aimed to evaluate the effect of budesonide nebulization in children with high serum total immunoglobulin E (tIgE) levels undergoing surgical repair of CHD via CPB. We conducted a randomized, single-center, controlled trial at a tertiary teaching hospital. One-hundred and one children with high tIgE were enrolled and randomized into the budesonide nebulization group (BUD group, n = 50) or the normal saline nebulization group (NS group, n = 51) between January 2020 and December 2020. Budesonide or normal saline was administered through a vibrating mesh nebulizer during mechanical ventilation every 8h. Blood and bronchoalveolar lavage fluid (BALF) samples were examined and data on airway mechanics and clinical outcomes were recorded. IL-6 and IL-8 levels in the blood and BALF samples significantly increased after CPB in both groups. Budesonide inhalation reduced IL-6 and IL-8 levels in the blood and BALF samples in children with high tIgE (P < 0.05). The mean airway pressure, PCO2, and oxygen index in the BUD group were significantly lower than those in the NS group after the first inhalation dose and persisted until almost 24h after surgery. The peak inspiratory pressure and drive pressure were lower in the BUD group than in the NS group at nearly 24h after surgery, with no significant difference at other time points. Additionally, the duration of mechanical ventilation, number of noninvasive ventilations after extubation, and number of patients using aerosol-inhaled bronchodilators after CICU in the BUD group were significantly lower than those in the NS group (P < 0.05). Children with high preoperative tIgE levels are at risk of airway inflammation after cardiopulmonary bypass. Inhaling budesonide during postoperative mechanical ventilation can reduce the intensity of inflammatory reactions, shorten the duration of mechanical ventilation, reduce airway pressure and the utilization of NIV after extubation.

Impact of targeted neonatal echocardiography consultations for critically sick preterm neonates

RationalePreterm neonates needing rescue treatments with inotropes and/or inhaled nitric oxide (iNO) (acute critical illnesses, ACIs) in neonatal intensive care units (NICUs) are at high risk of mortality. While targeted...

Vascular responsiveness to low-dose dexamethasone in extremely premature infants: negative influence of fetal growth restriction.

Dexamethasone is frequently prescribed for preterm infants to wean from respiratory support and/or to facilitate extubation. This pre-/postintervention prospective study ascertained the impact on clinical (respiratory support) and echocardiographic parameters after dexamethasone therapy in preterm fetal growth restriction (FGR) infants compared with appropriate for gestational age (AGA) infants. Echocardiography was performed within 24 h before the start and after completion of 10-day therapy. Parameters assessed included those reflecting pulmonary vascular resistance and right ventricular output. Seventeen FGR infants (birth gestation and birth weight, 25.2 ± 1.1 wk and 497 ± 92 g, respectively) were compared with 22 AGA infants (gestation and birth weight, 24.5 ± 0.8 and 663 ± 100 g, respectively). Baseline respiratory severity score (mean airway pressure × fractional inspired oxygen) was comparable between the groups, (median [interquartile range] FGR, 10 [6, 13] vs. AGA, 8 ± 2.8, P = 0.08). Pre-dexamethasone parameters of pulmonary vascular resistance (FGR, 0.19 ± 0.03 vs. AGA, 0.2 ± 0.03, P = 0.16) and right ventricular output (FGR, 171 ± 20 vs. 174 ± 17 mL/kg/min, P = 0.6) were statistically comparable. At post-dexamethasone assessments, the decrease in the respiratory severity score was significantly greater in AGA infants (median [interquartile range] FGR, 10 [6, 13] to 9 [2.6, 13.5], P = 0.009 vs. AGA, 8 ± 2.8 to 3 ± 1, P < 0.0001). Improvement in measures of pulmonary vascular resistance (ratio of time to peak velocity to right ventricular ejection time) was greater in AGA infants (FGR, 0.19 ± 0.03 to 0.2 ± 0.03, P = 0.13 vs. AGA 0.2 ± 0.03 to 0.25 ± 0.03, P < 0.0001). The improvement in right ventricular output was significantly greater in AGA infants (171 ± 20 to 190 ± 21, P = 0.014 vs. 174 ± 17 to 203 ± 22, P < 0.0001). This highlights differential cardiorespiratory responsiveness to dexamethasone in extremely preterm FGR infants, which may reflect the in utero maladaptive state.NEW & NOTEWORTHY Dexamethasone (DEX) is frequently used in preterm infants dependent on ventilator support. Differences in vascular structure and function that may have developed prenatally arising from the chronic intrauterine hypoxemia in FGR infants may adversely affect responsiveness. The clinical efficacy of DEX was significantly less in FGR (birth weight < 10th centile) infants, compared with appropriate for gestational age (AGA) infants. Echocardiography showed significantly less improvement in pulmonary vascular resistance in FGR, compared with AGA infants.

Early predictive values of clinical assessments for ARDS mortality: a machine-learning approach

Acute respiratory distress syndrome (ARDS) is a devastating critical care syndrome with significant morbidity and mortality. The objective of this study was to evaluate the predictive values of dynamic clinical indices by developing machine-learning (ML) models for early and accurate clinical assessment of the disease prognosis of ARDS. We conducted a retrospective observational study by applying dynamic clinical data collected in the ARDSNet FACTT Trial (n = 1000) to ML-based algorithms for predicting mortality. In order to compare the significance of clinical features dynamically, we further applied the random forest (RF) model to nine selected clinical parameters acquired at baseline and day 3 independently. An RF model trained using clinical data collected at day 3 showed improved performance and prognostication efficacy (area under the curve [AUC]: 0.84, 95% CI: 0.78–0.89) compared to baseline with an AUC value of 0.72 (95% CI: 0.65–0.78). Mean airway pressure (MAP), bicarbonate, age, platelet count, albumin, heart rate, and glucose were the most significant clinical indicators associated with mortality at day 3. Thus, clinical features collected early (day 3) improved performance of integrative ML models with better prognostication for mortality. Among these, MAP represented the most important feature for ARDS patients’ early risk stratification.

Ethnicity and Observed Oxygen Saturations, Fraction of Inspired Oxygen, and Clinical Outcomes: A Post-Hoc Analysis of the Oxy-PICU Trial of Conservative Oxygenation.

A conservative oxygenation strategy, targeting peripheral oxygen saturations (Sp o2 ) between 88% and 92% in mechanically ventilated children in PICU, was associated with a shorter duration of organ support and greater survival compared with Sp o2 greater than 94% in our recent Oxy-PICU trial. Sp o2 monitors may overestimate arterial oxygen saturation (Sa o2 ) in patients with higher levels of skin pigmentation compared with those with less skin pigmentation. We investigated if ethnicity was associated with changes in distributions of Sp o2 and F io2 and outcome. Post-hoc analysis of a pragmatic, open-label, multicenter randomized controlled trial. Fifteen PICUs across the United Kingdom and Scotland. Children aged 38 weeks corrected gestational age to 15 years accepted to a participating PICU as an unplanned admission and receiving invasive mechanical ventilation with supplemental oxygen for abnormal gas exchange. Hierarchical regression models for Sp o2 and F io2 , and ordinal models for the primary trial outcome of a composite of the duration of organ support at 30 days and death, were used to examine the effects of ethnicity, accounting for baseline Sp o2 , F io2 , and mean airway pressure and trial allocation. Ethnicity data were available for 1577 of 1986 eligible children, 1408 (89.3%) of which were White, Asian, or Black. Sp o2 and F io2 distributions did not vary according to Black or Asian ethnicity compared with White children. The trial primary outcome measure also did not vary significantly with ethnicity. The point estimate for the treatment effect of conservative oxygenation in Black children was 0.64 (95% CI, 0.33-1.25) compared with 0.84 (0.68-1.04) in the overall trial population. These data do not suggest that the association between improved outcomes and conservative oxygenation strategy in mechanically ventilated children in PICU is modified by ethnicity.

Effects of nursing team communication and collaboration on treatment outcomes in intensive care unit patients with severe pneumonia.

Severe pneumonia is a common severe respiratory infection worldwide, and its treatment is challenging, especially for patients in the intensive care unit (ICU). To explore the effect of communication and collaboration between nursing teams on the treatment outcomes of patients with severe pneumonia in ICU. We retrospectively analyzed 60 patients with severe pneumonia who were treated at the ICU of the hospital between January 1, 2021 and December 31, 2023. We compared and analyzed the respiratory mechanical indexes [airway resistance (Raw), mean airway pressure (mPaw), peak pressure (PIP)], blood gas analysis indexes (arterial oxygen saturation, arterial oxygen partial pressure, and oxygenation index), and serum inflammatory factor levels [C-reactive protein (CRP), procalcitonin (PCT), cortisol (COR), and high mobility group protein B1 (HMGB1)] of all patients before and after treatment. Before treatment, there was no significant difference in respiratory mechanics index and blood gas analysis index between 2 groups (P > 0.05). However, after treatment, the respiratory mechanical indexes of patients in both groups were significantly improved, and the improvement of Raw, mPaw, plateau pressure, PIP and other indexes in the combined group after communication and collaboration with the nursing team was significantly better than that in the single care group (P < 0.05). The serum CRP and PCT levels of patients were significantly decreased, and the difference was statistically significant compared with that of nursing group alone (P < 0.05). The levels of serum COR and HMGB1 before and after treatment were also significantly decreased between the two groups. The communication and collaboration of the nursing team have a significant positive impact on respiratory mechanics indicators, blood gas analysis indicators and serum inflammatory factor levels in the treatment of severe pneumonia patients in ICU.

Stabilization, respiratory care and survival of extremely low birth weight infants transferred on the first day of life.

To assess stabilization, respiratory care and survival of extremely low birth weight (ELBW, <1000 g at birth) infants requiring emergency transfer to tertiary NICUs on the first day of life. Retrospective cohort study of 55 ELBW infants transported by a dedicated neonatal transport service over a 65-month period. Ventilator data were downloaded computationally. 95% of infants were intubated and received surfactant prior to transfer. Median expired tidal volume was 5.0 mL/kg (interquartile range: 4.6-6.2 mL/kg). Infants ventilated with SIPPV had significantly higher mean airway pressure and minute ventilation, but similar FiO2 compared to babies on SIMV. Blood gases showed significant improvement during transport. 55% of infants survived to discharge from NICU. Most ELBW infants transferred on the first day of life require mechanical ventilation and can be ventilated with 5 mL/kg tidal volume.