Rate Of Respiratory Distress Syndrome Research Articles

Sodium propionate ameliorates lipopolysaccharide-induced acute respiratory distress syndrome in rats via the PI3K/AKT/mTOR signaling pathway.

Acute respiratory distress syndrome (ARDS) is a severe lung disease characterized by significant hypoxemia, which impairs the oxygen supply necessary for optimal lung function. This study aimed to investigate the effects of sodium propionate (SP), the primary end product of intestinal flora fermentation of dietary fiber, on lipopolysaccharide (LPS)-induced ARDS in rats. The rats were treated with SP, after which the lung wet/dry ratio, arterial partial oxygen pressure (PaO2), levels of pro- and anti-inflammatory cytokines, tight junction proteins ZO-1 and Occludin, as well as LC3 and phosphorylated PI3K (p-PI3K)/p-AKT/p-mTOR protein levels, were measured. Additionally, histopathological analysis was conducted. The results indicated that SP effectively alleviated arterial hypoxemia in rats and mitigated the pathological damage to both intestinal and lung tissues caused by LPS. Notably, SP significantly reduced the levels of inflammatory factors TNF-α and IL-6 in the blood and bronchoalveolar lavage fluid (BALF) of ARDS rats, while increasing the concentration of the anti-inflammatory factor IL-10. Furthermore, SP inhibited the activation of the PI3K/AKT/mTOR signaling pathway and enhanced the LC3II/LC3I ratio in lung tissue. Therefore, SP may improve LPS-induced ARDS in rats by inhibiting the activation of the PI3K/AKT/mTOR signaling pathway, promoting autophagy, decreasing the production and release of inflammatory markers, and reducing alveolar epithelial damage.

The effect of varasurf surfactant on respiratory distress syndrome in rats

The effect of varasurf surfactant on respiratory distress syndrome in rats

Hydroxychloroquine attenuates sepsis-induced acute respiratory distress syndrome in rats.

This study investigates the effects of hydroxychloroquine (HCQ) on a sepsis-induced acute respiratory distress syndrome (ARDS) model in rats, initiated by a fecal intraperitoneal injection procedure (FIP). Three groups were established: control (n=8), FIP + saline (n=7), and FIP + HCQ (20 mg/kg/day) (n=9). Blood samples were collected for arterial blood gas and biochemical analyses, and bilateral pneumonectomy was performed for histopathologic examination. In the FIP + saline group, PaO2 decreased and PaCO2 increased, whereas these levels normalized in the FIP + HCQ group compared to the control (p<0.001 and p<0.05, respectively). Histopathological scores for alveolar congestion, perivascular/interstitial edema, hemorrhage in alveolar tissue, leukocyte infiltration or aggregation in air spaces/vascular walls, and alveolar wall/hyaline membrane thickness increased in the FIP + saline group compared to the control group (p<0.01). These scores decreased in the FIP + HCQ group compared to the FIP + saline group (p<0.01). HCQ reversed the sepsis-induced increase in malondialdehyde, tumor necrosis factor-alpha, interleukin-6, and lactic acid. HCQ may be an effective and safe option to mitigate the severe progression of ARDS.

Clinical cause of neonatal mortality in Iran: analysis of the national Iranian Maternal And Neonatal network

BackgroundThe neonatal mortality rate is a main indicator of the health and development of a country. Having insight into the cause of neonatal deaths may be the first step to...

Therapeutic action of the ethanolic extract of Platonia insignis Mart. leaves on induced respiratory distress syndrome in rats

Therapeutic action of the ethanolic extract of Platonia insignis Mart. leaves on induced respiratory distress syndrome in rats

EVALUATION OF MORBIDITY AND MORTALITY OF THE NEWBORN ADMITTED TO SPECIAL NEWBORN CARE UNIT

Objectives: Under the facility-based newborn care scheme (FBNC), special newborn care units (SNCUs) are being established in India with the primary motto of reducing the neonatal mortality rate (NMR). Methods: The present study was a retrospective study conducted for 2 years to gain knowledge of the functioning of SNCU, and its morbidity and mortality pattern of sick newborn attending were evaluated in the present research. The study was conducted at SNCU, SVRRGGH, Tirupati. The total admissions were male, referrals from outside facilities, and low birth-weight newborns. Results: The overall leading cause of admissions was birth asphyxia-related morbidity (BA) (24%), infections (22.2%), followed by respiratory distress syndrome (RDS) (15.3%). The causes of mortality were BA (33.2%), followed by RDS (27%) and infections (16.4%). The case fatality rates of RDS (45%) were the highest, followed by meconium aspiration syndrome (40%) and BA (35.6%). Although morbidity was high, case-fatality rate of infections (16.4%) was low. Conclusion: This study has highlighted the deficiencies at SNCU influencing the outcome of admitted newborns, thus guiding steps for improvisation.

Neonatal outcomes of elective caesarean section at term without prophylactic use of antenatal corticosteroids

Background: We aimed to describe the outcomes of neonates born at or near term to women undergoing elective C-section without prophylactic corticosteroids. Methods: Single-centre retrospective observational study of neonates born between 36+0 and 42+0 weeks. Associations between neonatal complications and maternal and neonatal factors were evaluated by univariate analyses and multivariate logistic regression. Results: A total of 2151 (26%) neonates were born by elective C-section during the study period, of whom 429 were included in the study. Fifty-six (13.05%) neonates developed some complication with 39 (9.1%) requiring NICU admission. Respiratory distress syndrome (RDS) and hypoglycemia occurred in 21 (4.9%) and 7 (1.6%) neonates, respectively. Maternal age &gt;35 was associated with higher odds of neonatal complications (OR: 5.52, 95% CI: 1.02-29.74, p=0.047). Conclusions: The rate of RDS was comparable to other reported studies. The study revealed a high rate of term elective C-sections, providing grounds for conducting further research on administering antenatal corticosteroid to this population to reduce new-born morbidities.

The interaction of maternal obesity and administered betamethasone in the development of fetal respiratory distress syndrome

IntroductionThe current study evaluated the effect of obesity on neonatal respiratory distress syndrome (RDS) in pregnant women who were administered ACSs due to the risk of preterm birth and delivered before 34 weeks of gestation.Material and methodsIn this retrospective study, 414 pregnant women who had a singleton pregnancy, were aged 18–40 years, and received two doses of ACS 24 h apart administered between 23+0/7 and 33+5/7 gestation weeks due to the risk of a preterm birth were included. For maximum fetal effect, those who completed the 48-hour steroid treatment and delivered before 34 weeks of gestation were divided into three groups according to BMI at ACS administration.ResultsGestational age at ACS administration and gestational age at delivery were similar among groups.. Neonatal RDS occurred in 17 (18.6%) newborns in the normal weight group, 40 (17.1%) newborns in the overweight group, and 23 (25.5%) newborns in the obese group. After adjusting for independent effects from maternal age, gestational age at ACS administration, gestational age at delivery, emergency cesarean delivery, fetal birth weight, and fetal gender, we found that RDS rates were significantly higher in the obese group.ConclusionsOur results suggest that maternal obesity reduces the effects of ACS and that RDS rates are higher in neonates born before 34 weeks of gestation to obese mothers to whom ACS has been administered.Therefore, pregnant women who have a high BMI and who are at risk of preterm birth are more likely to require an adjustment in ACS dosing.

Preterm birth characteristics and outcomes in Portugal, between 2010 and 2018-A cross-sectional sequential study.

According to the World Health Organization, 11% of all children are born prematurely, representing 15 million births annually. An extensive analysis on preterm birth, from extreme to late prematurity and associated deaths, has not been published. The authors characterize premature births in Portugal, between 2010 and 2018, according to gestational age, geographic distribution, month, multiple gestations, comorbidities, and outcomes. A sequential, cross-sectional, observational epidemiologic study was conducted, and data were collected from the Hospital Morbidity Database, an anonymous administrative database containing information on all hospitalizations in National Health Servicehospitals in Portugal, and coded according to the ICD-9-CM (International Classification of Diseases), until 2016, and ICD-10 subsequently. Data from the National Institute of Statistics was utilized to compare the Portuguese population. Data were analyzed using R software. In this 9-year study, 51.316 births were preterm, representing an overall prematurity rate of 7.7%. Under 29 weeks, birth rates varied between 5.5% and 7.6%, while births between 33 and 36 weeks varied between 76.9% and 81.0%. Urban districts presented the highest preterm rates. Multiple births were 8× more likely preterm and accounted for 37%-42% of all preterm births. Preterm birth rates slightly increased in February, July, August, and October. Overall,respiratory distress syndrome (RDS), sepsis, and intraventricular hemorrhagewere the most common morbidities. Preterm mortality rates varied significantly with gestational age. In Portugal, 1 in 13 babies was born prematurely. Prematurity was more common in predominantly urban districts, a surprise finding that warrants further studies. Seasonal preterm variation rates also require further analysis and modelling to factor in heat waves and low temperatures. A decrease in the case rate of RDS and sepsis was observed. Compared with previously published results, preterm mortality per gestational age decreased; however, further improvements are attainable in comparison with other countries.

Anti-inflammatory and antioxidant activities of Gymnema Sylvestre extract rescue acute respiratory distress syndrome in rats via modulating the NF-κB/MAPK pathway.

Acute respiratory distress syndrome (ARDS) is one of the major causes of mortality in COVID-19 patients, due to limited therapeutic options. This prompted us to explore natural sources to mitigate this condition. Gymnema Sylvestre (GS) is an ancient medicinal plant known to have various therapeutic effects. This investigation examined the therapeutic effect of hydroalcoholic extract of Gymnema Sylvestre (HAEGS) against lipopolysaccharide (LPS)-induced lung injury and ARDS in in vitro and in vivo models. UHPLC-HRMS/GC-MS was employed for characterizing the HAEGS and identified several active derivatives including gymnemic acid, gymnemasaponins, gymnemoside, gymnemasin, quercetin, and long fatty acids. Gene expression by RT-qPCR and DCFDA analysis by flow cytometry revealed that several inflammatory cytokine/chemokine, cell injury markers, and reactive oxygen species (ROS) levels were highly upregulated in LPS control and were significantly reduced upon HAEGS treatment. Consistent with the in vitro studies, we found that in LPS-induced ARDS model, pre-treatment with HAEGS significantly suppressed the LPS-induced elevation of inflammatory cell infiltrations, cytokine/chemokine marker expression, ROS levels, and lung injury in a dose-dependent manner. Further mechanistic studies demonstrated that HAEGS suppressed oxidative stress by modulating the NRF2 pathway and ameliorated the ARDS through the NF-κB/MAPK signalling pathway. Additional fractionation results revealed that fraction 6 which has the exclusive composition of gymnemic acid derivatives showed better anti-inflammatory effects (inhibition of IL-6 and IL-1β) at lower concentrations compared to HAEGS. Overall, HAEGS significantly mitigated LPS-induced lung injury and ARDS by targeting the NF-κB/MAPK signalling pathway. Thus, our work unravels the protective role of HAEGS for the first time in managing ARDS.

Factors associated with respiratory distress syndrome in preterm neonates admitted to a tertiary hospital in Kabul city: A retrospective cross-sectional study

BackgroundPrematurity is one of the primary causes of infant death in Afghanistan, and it complicates a variety of critical issues, such as respiratory distress syndrome (RDS). Although RDS has been associated with serious consequences, there is a lack of scientific information on the associated factors of this problem in Afghanistan; hence, this study was undertaken to fill that gap. The purpose of this study was to find the occurrence rate and associated factors of RDS in premature neonates. MethodsThis retrospective cross-sectional study was conducted at the Neonatal Intensive Care Unit of the French Medical Institute for Mothers and Children Hospital in Kabul City, Afghanistan during 2020–2021. Statistical analysis was performed by SPSS 26 and specific statistical methods. ResultsA total of 78 preterm newborns were enrolled in this study, and respiratory distress syndrome developed in 51.3% of them. Based on gestational age, the occurrence rates of RDS within groups of extremely, early, moderate and late preterm neonates were 100%, 55.6%, 44%, and 35.7% respectively. The occurrence of RDS was found to be 100% in extremely low birth weight, 56.2% in very low birth weight, and 58.8% in low birth weight neonates. The gestational ages of these infants had a positive correlation with birth weights (r = 0.648, p = 0.01, n = 78). The preterm neonates in the RDS group versus the non-RDS group had a mean birth weight of (1610±314.4 g vs 1981±520.3 g,P = 0.005), a mean gestational age of (31.65±2.2 w vs 33.18± 2.10 w,P = 0.003), and a mean hemoglobin level of (13.85± 3.28 g vs16.09± 3.26 g, P = 0.003). There was a significant association between RDS and neonatal anemia (AOR=5.9, P = 0.008), neonatal sepsis (AOR=4.2, P = 0.01), vaginal delivery (AOR=8.7, P = 0.01), delivery at low-resourced settings (AOR=2.7, P = 0.01), PROM (AOR=4, P = 0.02), and antepartum hemorrhage (6.9, P = 0.01). The mortality rate in preterm neonates was found to be 26.8% that was significantly associated with very and extremely low birth weights (AOR=8.2, P = 0.03), early and extremely preterm births (AOR=6.3, P = 0.03), female gender (AOR=3.8, P = 0.04), antepartum hemorrhage (AOR=4.6, P = 0.01) and PROM (AOR=5.7, P = 0.01). ConclusionsRDS was highly prevalent in preterm newborns, and the highest rates were seen within groups of extremely preterm and extremely low-birth-weight newborn babies. RDS was found to be associated with lower neonatal birth weight, gestational age, and hemoglobin level, as well as neonatal anemia, neonatal sepsis, vaginal delivery, birth in low-resource settings, PROM, and antepartum hemorrhage. The neonatal mortality in preterm neonates was higher than high-income country. Proper management of the aforementioned associated factors will reduce the incidence of RDS and neonatal mortality in preterm neonates.

Lung Injury Is Induced by Abrupt Increase in Respiratory Rate but Prevented by Recruitment Maneuver in Mild Acute Respiratory Distress Syndrome in Rats.

Gradually changing respiratory rate (RR) during time to reduce ventilation-induced lung injury has not been investigated. The authors hypothesized that gradual, compared with abrupt, increments in RR would mitigate ventilation-induced lung injury and that recruitment maneuver before abruptly increasing RR may prevent injurious biologic impact. Twenty-four hours after intratracheal administration of Escherichia coli lipopolysaccharide, 49 male Wistar rats were anesthetized and mechanically ventilated (tidal volume, 6 ml/kg; positive end-expiratory pressure, 3 cm H2O) with RR increase patterns as follows (n = 7 per group): (1) control 1, RR = 70 breaths/min for 2 h; (2) and (3) abrupt increases of RR for 1 and 2 h, respectively, both for 2 h; (4) shorter RR adaptation, gradually increasing RR (from 70 to 130 breaths/min during 30 min); (5) longer RR adaptation, more gradual increase in RR (from 70 to 130 breaths/min during 60 min), both for 2 h; (6) control 2, abrupt increase of RR maintained for 1 h; and (7) control 3, recruitment maneuver (continuous positive airway pressure, 30 cm H2O for 30 s) followed by control-2 protocol. At the end of 1 h of mechanical ventilation, cumulative diffuse alveolar damage scores were lower in shorter (11.0 [8.0 to 12.0]) and longer (13.0 [11.0 to 14.0]) RR adaptation groups than in animals with abrupt increase of RR for 1 h (25.0 [22.0 to 26.0], P = 0.035 and P = 0.048, respectively) and 2 h (35.0 [32.0 to 39.0], P = 0.003 and P = 0.040, respectively); mechanical power and lung heterogeneity were lower, and alveolar integrity was higher, in the longer RR adaptation group compared with abruptly adjusted groups; markers of lung inflammation (interleukin-6), epithelial (club cell secretory protein [CC-16]) and endothelial cell damage (vascular cell adhesion molecule 1 [VCAM-1]) were higher in both abrupt groups, but not in either RR adaptation group, compared with controls. Recruitment maneuver prevented the increase in VCAM-1 and CC-16 gene expressions in the abruptly increased RR groups. In mild experimental acute respiratory distress syndrome in rats, gradually increasing RR, compared with abruptly doing so, can mitigate the development of ventilation-induced lung injury. In addition, recruitment maneuver prevented the injurious biologic impact of abrupt increases in RR.

The Outcome- or Cost-Effectiveness Analysis of LUS-Based Care or CXR-Based Care of Neonatal Lung Diseases: The Clinical Practice Evidence from a Level Ⅲ NICU in China.

To compare the effect of managing neonatal lung disease with lung ultrasound (LUS) or chest X-ray (CXR) monitoring on health outcomes and cost-effectiveness. The data obtained from the NICU of the Beijing Chaoyang District Maternal and Child Healthcare Hospital were used as the study group, as LUS has completely replaced CXR in managing newborn lung disease in the hospital for the past 5 years. The primary outcomes of this study were the misdiagnosis rate of respiratory distress syndrome (RDS), the using status of mechanical ventilation, the incidence rate of bronchopulmonary dysplasia (BPD) and the survival rate in hospitalized infants. The secondary outcomes included the use pulmonary surfactant (PS), and the mortality rate of severe diseases (such as pneumothorax, pulmonary hemorrhage and RDS, etc.). Managing neonatal lung disease with LUS monitoring may enable the following effects: The frequency of ventilator use reducing by 40.2%; the duration of mechanical ventilation reducing by 67.5%; and the frequency of ventilator weaning failure being totally avoided. A misdiagnosis rate of 30% for RDS was also avoided. The dosage of PS was significantly reduced by 50% to 75%. No BPD occurred in the LUS-based care group for 5 years. The fatality rates of RDS, pneumothorax and pulmonary hemorrhage decreased by 100%. The poor prognosis rate of VLBW infants decreased by 85%, and the total mortality rate of hospitalized infants decreased by 90%. Therefore, the cost of LUS-based care was inevitably saved. Diagnosing and managing neonatal lung diseases with LUS monitoring have significant benefits, and this technology should be widely promoted and applied around the world.

Lung ultrasound to guide the administration of exogenous pulmonary surfactant in respiratory distress syndrome of newborn infants: A retrospective investigation study.

Respiratory distress syndrome (RDS) is a common disease that seriously endangers the life and safety of newborns, especially premature infants. Exogenous pulmonary surfactant (PS) is the specific agent for the treatment of neonatal RDS. Lung ultrasound (LUS) has been successfully used in the diagnosis of RDS, but its value in guiding the application of PS is still unclear. This paper explored whether the application of PS under LUS monitoring has some advantages, including (1) decreasing the misdiagnosis rate of RDS and decreasing probability of using PS, and (2) reducing the dose of PS without reducing the therapeutic effect. This study included two parts. Part 1: To decide whether the LUS is good to differentiate RDS from other lung diseases in the premature infants. All patients who were diagnosed with RDS and required PS treatment based on conventional criteria were routinely examined by LUS. Then, according to LUS findings, we decided whether they needed to receive PS treatment. Part 2: To see the dose reduction of surfactant is applicable. In RDS patients diagnosed based on LUS presentation and treated with Curosurf (Chiesi Pharmaceutical, Parma, Italy), the dose of Curosurf was compared with that recommended by the European RDS management guidelines. (1) Since March 2017, 385 newborn infants admitted to our neonatal intensive care unit met the traditional diagnostic criteria of RDS. Of these, only 269 cases were diagnosed with RDS and needed PS treatment according to LUS manifestations. The other 116 infants who did not meet the criteria for ultrasound diagnosis of RDS did not receive PS supplementation but obtained good outcomes, that is LUS findings decreased a misdiagnosis rate of RDS by 30.1% and subsequently resulted in a 30.1% reduction in PS use. (2) Among the 269 RDS patients diagnosed based on LUS findings, 148 were treated with Curosurf (another 121 RDS infants who received domestic PS treatment were not included in the study group), and the average dose was 105.4 ± 24.3 mg/kg per time, which is significantly lower than the dose of 200 mg/kg per time recommended by the European RDS guidelines. (3) The mortality rate of RDS patients was 0%, and no patients had ventilator-associated pneumonia or bronchopulmonary dysplasia in this study. LUS can decrease the misdiagnosis rate of RDS, thereby decreasing the probability of using PS and decreasing the dose of PS, and can help RDS infants to achieve better outcomes.

D-tagatose protects against oleic acid-induced acute respiratory distress syndrome in rats by activating PTEN/PI3K/AKT pathway.

Acute respiratory distress syndrome (ARDS) is characterized by disruption of the alveolar–capillary barrier, resulting in severe alveolar edema and inflammation. D-tagatose (TAG) is a low-calorie fructose isomer with diverse biological activities whose role in ARDS has never been explored. We found that TAG protects lung tissues from injury in the oleic acid-induced rat model of ARDS. Seventeen male Sprague–Dawley rats were randomly assigned to 3 groups: Sham (n = 5), ARDS (n = 6), and TAG + ARDS (n = 6). The treatment groups were injected with oleic acid to induce ARDS, and the TAG + ARDS group was given TAG 3 days before the induction. After the treatments, the effect of TAG was evaluated by blood gas analysis and observing the gross and histological structure of the lung. The results showed that TAG significantly improved the oxygenation function, reduced the respiratory acidosis and the inflammatory response. TAG also improved the vascular permeability in ARDS rats and promoted the differentiation of alveolar type II cells, maintaining the stability of the alveolar structure. This protective effect of TAG on the lung may be achieved by activating the PTEN/PI3K/AKT pathway. Thus, TAG protects against oleic acid-induced ARDS in rats, suggesting a new clinical strategy for treating the condition.

Incidence of Respiratory Distress Syndrome and Its Associated Factors among Preterm Neonates: Study from West Java Tertiary Hospital

Respiratory distress syndrome (RDS) or hyaline membrane disease is the most frequent cause of respiratory failure and mortality in preterm infants. As a result, many infants are brought to a neonatal intensive care unit (NICU). There may also be other factors that affect the incidence rate of RDS as well. Our research goals are to find out the incidence rate of RDS among three preterm groups and its related factors. In a cross-sectional-descriptive analytical study, newborn data was gathered and assessed by using hospital medical records. One hundred forty-two preterm infants with gestational age ≤ 36 weeks were hospitalized in the NICU. All participants were divided into three groups: extremely preterm ( 28 weeks), very preterm (28 to 32 weeks), and moderate-to-late preterm (32 to 36 weeks). The frequency of RDS and some related factors were compared among three groups. Finally, we analyzed the relationship between variables by SPSS statistics software version 19. The level of significance was considered P 0.05. Respiratory distress syndrome was observed in 64.68% of all participants; RDS is more common in infants within 28-32 weeks of gestation (81%), while infants with 28 weeks of gestation and 33-36 weeks of gestation have lower rates (50% and 52 Our study shows a positive correlation between birthweight and RDS as well as between birthweight and gestational age. (P value: 0.001, 0.003). Infants between 28 to 32 gestational age have a higher risk of RDS. The risk of RDS also increases in low birth weight and male infants.

Efficacy and safety of nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure ventilation in neonatal respiratory distress syndrome: a systematic review and meta-analysis.

BackgroundThe efficacies of nasal continuous positive airway pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV) in neonatal respiratory distress syndrome (RDS) are controversial. The reasons for controversy may be the selection bias of research objects and the small sample size.MethodsLiterature retrieval was performed in PubMed, EMBASE, Medline, Central, China National Knowledge Infrastructure (CNKI), Wanfang and China Science Digital Library (CSDL) databases. Inclusion criteria: (I) literatures involving subjects who were newborns with RDS; (II) studies that had established both experimental and control groups; (III) the intervention measures of the experimental and control groups were NIPPV and NCPAP, respectively; (IV) the results included the incidence of intubation, bronchopulmonary dysplasia (BPD), or mortality; and (V) randomized controlled trials (RCTs). The chi-square test was applied for heterogeneity test. Publication bias assessment was conducted by funnel plot and Egger’s test. The revised Cochrane risk of bias tool for individually randomized, parallel group trials (RoB2.0) was used to evaluate the risk of bias of the included RCT research.ResultsA total of 10 literatures were included for analysis, including 1,104 patients, 557 in the NIPPV group and 547 in the NCPAP group. Among the literatures, 2 literatures had low risk of bias, 2 literatures had high risk of bias, and the rest had uncertain risk of bias. Compared to NCPAP, NIPPV reduced the incidence of neonatal intubation in RDS [risk ratio (RR) =0.57, 95% confidence interval (CI): 0.46–0.71, Z=5.11, P<0.00001]. There was no statistically significant heterogeneity (P=0.13, I2=36%) or publication bias (P<0.05) among the studies. Compared with NCPAP, NIPPV reduced the incidence of BPD in RDS (RR =0.72, 95% CI: 0.57–0.91, Z=2.70, P=0.007). There was no statistically significant heterogeneity (P=0.10, I2=41%) or publication bias (P>0.05) among the studies. NIPPV reduced the neonatal mortality rate of RDS (RR =0.55, 95% CI: 0.31–0.97, Z=2.08, P=0.04). There was no statistically significant heterogeneity (P=0.20, I2=38%) or publication bias (P>0.05) among the studies.DiscussionCompared with NCPAP, NIPPV can reduce the incidence of intubation, BPD, and mortality. The conclusions need to be confirmed via high-quality RCTs.

Pre-treatment with morphine prevents lipopolysaccharide-induced acute respiratory distress syndrome in rats via activation of opioid receptors

PurposeAcute respiratory distress syndrome (ARDS), a severe medical condition, is among the major causes of death in critically ill patients. Morphine is used as a therapeutic agent against severe pain. The mechanisms of its reactions over ARDS are not fully understood. The aim of this study was to assess the mechanism of morphine in rats with ARDS. MethodsRats were injected with lipopolysaccharide to induce ARDS, and some rats were pre-treated with graded doses of morphine in the lateral ventricles to assess survival and non-infected mortality. Immunohistochemical and HE staining were performed to measure MPO and CD68 activity in the lungs and lung injury. ELISA was conducted to detect the inflammatory factor levels in the plasma and BALF. Co-labeling of μ-opioid receptor (MOR) and c-Fos was observed in the brain tissues. MOR-positive cells in brain tissues were evaluated using immunohistochemistry. The effect of MOR antagonists on ARDS was examined in rats by pre-injection of naloxone or methylnaltrexone. The expression of MyD88, TLR4, and NF-κB was lastly assessed. ResultsDose-independent improvement was observed in respiratory capacity and lung injury in ARDS rats after morphine pre-injection, along with reduced inflammatory factors in the plasma and BALF. MOR-positive cells were elevated after morphine, which occurred within the ventral part of the gigantocellular reticular nucleus (GiV). Naloxone and methylnaltrexone blocked the effects of morphine via central and peripheral MOR. Morphine activated TLR pathway in a MyD88-dependent manner. ConclusionMorphine activates MOR within the GiV and the TLR pathway to attenuate ARDS in rats.

Lipopolysaccharide induces acute lung injury and alveolar haemorrhage in association with the cytokine storm, coagulopathy and AT1R/JAK/STAT augmentation in a rat modelthat mimics moderate and severe Covid-19 pathology.

Progress in the study of Covid-19 disease in rodents has been hampered by the lack of angiotensin-converting enzyme 2 (ACE2; virus entry route to the target cell) affinities for the virus spike proteins across species. Therefore, we sought to determine whether a modified protocol of lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in rats can mimic both cell signalling pathways as well as severe disease phenotypes of Covid-19 disease. Rats were injected via intratracheal (IT) instillation with either 15mg/kg of LPS (model group) or saline (control group) before being killed after 3days. A severe acute respiratory syndrome (SARS)-like effect was observed in the model group as demonstrated by the development of a "cytokine storm" (>2.7 fold increase in blood levels of IL-6, IL-17A, GM-CSF, and TNF-α), high blood ferritin, demonstrable coagulopathy, including elevated D-dimer (approximately 10-fold increase), PAI-1, PT, and APTT (p<0.0001). In addition, LPS increased the expression of lung angiotensin II type I receptor (AT1R)-JAK-STAT axis (>4 fold increase). Chest imaging revealed bilateral small patchy opacities of the lungs. Severe lung injury was noted by the presence of both, alveolar collapse and haemorrhage, desquamation of epithelial cells in the airway lumen, infiltration of inflammatory cells (CD45+ leukocytes), widespread thickening of the interalveolar septa, and ultrastructural alterations similar to Covid-19. Thus, these findings demonstrate that IT injection of 15mg/kg LPS into rats, induced an AT1R/JAK/STAT-mediated cytokine storm with resultant pneumonia and coagulopathy that was commensurate with moderate and severe Covid-19 disease noted in humans.

Extraction of baicalin from Scutellaria baicalensis Georgi and its alleviative effect on acute respiratory distress syndrome in rats

In this study baicalin was extracted from Scutellaria baicalensis Georgi and applied to alleviate the acute respiratory distress syndrome (ARDS) in rats. The baicalin with 89.53% purity was successfully extracted from Scutellaria baicalensis Georgi. Sixty-five rats were randomly divided into control, model and low-, middle- and high-dose baicalin groups. The oleic acid-induced ARDS model was established in model and baicalin groups. The low-, middle- and high-dose baicalin groups were treated with 100, 200 and 400 mg/kg baicalin, respectively. After 3 h from treatment, compared with model group, in baicalin groups the arterial oxygen partial pressure and oxygenation index were obviously enhanced, the left lung ratio wet weight to dry weight and number of neutrophil, total protein content, tumor necrosis factor α, interleukin 1β and interleukin 6 levels in bronchoalveolar lavage fluid were significantly decreased, and the lung tissue high-mobility group box-1 (HMGB1) and nuclear factor kappa B (NF-κB) p65 protein expression levels were significantly decreased. In conclusion, baicalin may alleviate the ARDS in rats by reducing the inflammatory response via inhibiting the HMGB1/NF-κB signal pathway.