Traumatic Lung Research Articles

Early extubation is associated with shorter duration of mechanical ventilation and lower incidence of bronchopulmonary dysplasia

IntroductionRespiratory care of extremely preterm infants remains a challenge. The majority require invasive mechanical ventilation (MV), which is a contributing factor in developing bronchopulmonary dysplasia (BPD). It is important to keep MV to a minimum but there have been concerns that attempting extubation too early increases the risk for atelectasis, re-intubation, and further lung trauma. The aim of this study was to compare two different approaches to extubation. MethodsSingle-center, retrospective cohort study including infants born at 22 + 0–25 + 6 weeks during 2005–2009 and 2011–2015, before and after implementing guidelines recommending delayed extubation. Primary outcomes were BPD, duration of MV and length of hospital stay. ResultsEighty-eight infants in the early era and 102 infants in the late era were included. Infants in the first period were younger at first extubation attempt, and a higher number of infants were extubated within 24 h, 72 h, and one week after birth. The number of infants re-intubated and postnatal age at re-intubation did not differ between the groups. The incidence of severe BPD was 28% in the early period compared to 48% in the later (p < 0.01). Infants in the late period had longer duration of MV (17 vs 27 days, p < 0.01) but similar length of hospital stay (118 vs 123, p = 0.21). ConclusionAfter implementing guidelines recommending delayed extubation, the incidence of severe BPD was higher and the duration of MV was longer. This supports the strategy to attempt extubation early even in extremely preterm infants.

THE ROLE OF HMGB1 IN THE IMMUNE RESPONSE TO SARS-COV-2 INFECTION: FROM PATHOGENESIS TOWARDS A NEW POTENTIAL THERAPEUTIC TARGET

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is the most important emerging pathogen since it was discovered in late 2019, infecting millions of people worldwide. The human body's defence against this new viral respiratory infection depends on the immune response of each person with a crucial impact on the appearance of clinical signs. Therefore, it is important to identify endogenous molecules with a fundamental role in severe pulmonary inflammation associated with SARS-CoV-2 infection. The impact of high mobility group proteins (HMGBs) in the pathogenesis of coronavirus disease 2019 (COVID-19) was recently proposed. There is also recent evidence that HMGBs, particularly HMGB1–2, play important roles in the replication of viral genomes. Moreover, HMGB1–4 proteins appear to be associated with inflammatory processes in the pathogenesis of many other viral diseases and disorders, including lung disease, ischemia-reperfusion-injury, sepsis, coagulopathy, trauma, neurological disorders, and cancer. This article presents the possible roles of HMGB1 in SARS-CoV-2 replication and its involvement in the pathogenesis of clinical severe pulmonary manifestations;these data can be useful in further virologic studies and the finding of new potential therapeutic targets in COVID-19.

Fluid Therapy in Pulmonary Disease: How Careful Do We Need to Be?

Intravenous fluid therapy is a vital and life-saving therapeutic in veterinary medicine. In the absence of heart or lung disease, trauma or sepsis there is limited evidence that fluid therapy will have a detrimental effect on lung function. In healthy dogs there is a reasonable level of experimental evidence that supraphysiologic rates of fluid are required before signs of fluid overload are made evident. In cats, however, this may not be the case. There are higher rates of asymptomatic myocardial disease, but even in the absence of that it seems that some cats may be susceptible to fluid overload. Where systemic inflammation already exists the careful homeostatic and protective mechanisms within the lung are deranged and increases in hydrostatic pressure are more likely to result in fluid movement into the lung tissues. Strategies including restricting the use of intravenous crystalloid fluid administration and using blood products for management of severe hemorrhage are of increasing importance in human trauma and seem to be associated with fewer pulmonary complications, and lower mortality. Managing dogs and cats with sepsis and acute respiratory distress syndrome is already challenging, but ensuring adequate vascular expansion needs to be balanced with avoiding excessive volume administration which may negatively impact pulmonary function. While fluids remain crucial to management of these conditions, there will be an ongoing requirement to balance need without providing excess. The use of point of care ultrasound may provide clinicians with a non-invasive and accessible way to do this.

Incidental paratracheal air cyst in papillary thyroid cancer patient: a case report

Paratracheal air cyst (PTAC) is a collection of air in the right posterior side of the trachea with an uncertain etiology. We report a papillary thyroid cancer patient with a PTAC that was removed during thyroid cancer surgery. A 68-year-old woman was diagnosed with right papillary thyroid cancer with suspicion of central lymph node metastasis. She had a history of hypertension and a rear-end collision car accident 20 years prior. On computed tomography, an ovoid cyst was incidentally found in the paratracheal region at the thoracic inlet level. Emphysematous lung with an obstructive lung defect was noted without any symptoms. Bilateral total thyroidectomy with ipsilateral central compartment neck dissection was indicated for the patient. During surgery, removal of the cyst was inevitable for complete central neck dissection. Histopathologic analysis revealed an etiology of tracheal mucus sprouting through weak trachea points. No postoperative complications occurred. The patient continued on levothyroxine medication without further radioactive iodine therapy. After 6 months, follow-up ultrasound showed no evidence of recurrence. We hypothesized that obstructive lung disease with impaired lung function or trauma history might have contributed to the development of PTAC. Future studies are needed to determine if PTACs have any association with obstructive lung disease or trauma.

Damage control surgery in lung trauma.

Damage control techniques applied to the management of thoracic injuries have evolved over the last 15 years. Despite the limited number of publications, information is sufficient to scatter some fears and establish management principles. The severity of the anatomical injury justifies the procedure of damage control in only few selected cases. In most cases, the magnitude of the physiological derangement and the presence of other sources of bleeding within the thoracic cavity or in other body compartments constitutes the indication for the abbreviated procedure. The classification of lung injuries as peripheral, transfixing, and central or multiple, provides a guideline for the transient bleeding control and for the definitive management of the injury: pneumorraphy, wedge resection, tractotomy or anatomical resection, respectively. Identification of specific patterns such as the need for resuscitative thoracotomy, or aortic occlusion, the existence of massive hemothorax, a central lung injury, a tracheobronchial injury, a major vascular injury, multiple bleeding sites as well as the recognition of hypothermia, acidosis or coagulopathy, constitute the indication for a damage control thoracotomy. In these cases, the surgeon executes an abbreviated procedure with packing of the bleeding surfaces, primary management with packing of some selected peripheral or transfixing lung injuries, and the postponement of lung resection, clamping of the pulmonary hilum in the most selective way possible. The abbreviation of the thoracotomy closure is achieved by suturing the skin over the wound packed, or by installing a vacuum system. The management of the patient in the intensive care unit will allow identification of those who require urgent reintervention and the correction of the physiological derangement in the remaining patients for their scheduled reintervention and definitive management.

Renal Function and Pulmonary Fluid Balance in Porcine Models of Acute Lung Injury

Managing pulmonary edema is critical to maintaining blood oxygenation and perfusion for adequate tissue oxygen delivery after acute lung injury. While it is well recognized that renal failure often leads to complications of nephrogenic pulmonary edema, how the regulation of lung fluid is changed during altered renal function in conditions of traumatic injury is poorly understood. We hypothesized that control of lung water balance after a traumatic blunt force lung injury accompanied by a renal response to hemorrhage and hypotension would be different than after simple disruption of the alveolar-capillary liquid barrier interface. Hence, we compared the changes in effective lung water index (ELWI, measured by the Pulse Ion Contour Cardiac Output (PICCO), Getinge) method in a pig model of Traumatic Acute Lung Injury (TALI, n=9), and a model of diffuse alveolar-capillary barrier disruption with oleic acid (OA, n=5), versus a control group (n=10). Anesthetized, mechanically ventilated, Yorkshire cross male and female pigs (body weight 27.0 +/- 0.6 kg) were catheterized with a Swan Ganz catheter for measurement of pulmonary artery pressure and cardiac output determination by thermodilution. Pulmonary function, hemodynamics, and urinary output were examined before and after localized blunt right chest trauma (TALI), or oleic acid injection into the main pulmonary artery (OA 0.3 ml in 50% w/v ethanol). Pulmonary vasoconstriction was induced in the acute lung injury groups as indicated by an increase in pulmonary to systemic vascular resistance ratios in TALI (0.37 +/- 0.03) and OA (0.34 +/-0.08) compared to controls (0.21+/-0.02). TALI resulted in a decrease in mean arterial pressure (MAP, 46+/-4 mmHg) compared to controls (60 +/-2 mmHg) or OA (62+/-3 mm Hg). In all groups ELWI remained steady compared to pre-injury baseline. In the OA and control groups, circulating vasopressin decreased over the time course of the experiment (p<0.01) but did not decrease in the TALI group in accordance with the injury-induced hemorrhage and decreased MAP. Accordingly, urine flow decreased in the TALI group compared to OA and controls. Fractional excretion of water decreased in the OA and control groups, (p<0.01) but remained unchanged in TALI, indicating retention of water in OA and controls compared to TALI. The overall maintenance of ELWI despite differences in renal water handling in TALI compared to controls suggest that protection against pulmonary edema needs to be considered in treatment of hypotension with fluid resuscitation in traumatic lung injury.

Perioperative, protective use of extracorporeal membrane oxygenation in complex thoracic surgery.

Extracorporeal membrane oxygenation (ECMO) is increasingly used in patients undergoing complex thoracic surgical procedures. However, studies reporting the clinical outcomes of these patients are limited to case reports, without real consensus. Our aim was to evaluate the perioperative use of ECMO as respiratory and/or circulatory support in thoracic surgery: indications, benefits, and perioperative management. Between May 2013 and December 2018, we reviewed the clinical data of 15 patients (11 males and 4 females; mean age: 47 years old; range, 25-73 years) undergoing ECMO-assisted thoracic surgery in our hospital. Of the 15 patients, 10 cases received peripheral veno-arterial (VA) ECMO and five cases received veno-venous (VV) ECMO. Indications for ECMO were pulmonary transplantation with hard-to-maintain oxygenation (n = 5), traumatic main bronchial rupture (n = 2), traumatic lung injury (n = 1), airway tumor leading to severe airway stenosis (n = 2), huge thoracic mass infiltrated vena cava (n = 5). The ECMO duration was 1-51 hours. All patients were successfully extubated and weaned from ECMO postoperatively. The main complications were hemorrhage (26.7%), infection (33.3%), acute hepatic dysfunction (33.3%), and venous thrombosis (26.7%). There was only one hospital death and postoperative one-year survival rate was 86%. Our experience indicates that ECMO is a feasible method for complex trachea-bronchial surgery, huge thoracic mass excision and lung transplantation, and the ECMO-related risks may be justified. With further accumulation of experience with ECMO, a more sophisticated protocol for management of critical airway or heart failure problems in thoracic surgeries can be derived.

ECMO (extra corporeal membrane oxygenation) in major trauma: A 10 year single centre experience

Aim To review the indications, complications and outcomes of extracorporeal membrane oxygenation (ECMO) in major trauma patients.Methods Single centre, retrospective, cohort study.Results Over a ten year period, from 13,420 major trauma patients, 11 were identified from our institutional trauma registry as having received ECMO. These patients were predominantly younger (mean 39 +/- 17 years), male (91%) and severely traumatised (median ISS 50, IQR 34 - 54). Veno-venous (VV) ECMO was used predominantly (n = 7, 64%), to treat hypoxic respiratory failure (mean PaO2/FiO2 ratio 69.7 +/- 38.6), secondary to traumatic lung injury. Veno-arterial (VA) ECMO was used less frequently, primarily to treat massive pulmonary embolism following trauma. Major bleeding complications occurred in four patients, however only one patient died from haemorrhage. Heparin free (2/11), delayed (3/11) or low dose heparin (2/11) therapy was frequently utilised. The median time from injury to ECMO initiation was 1 day (IQR 0.5 – 5.5) and median ECMO duration 9 days (IQR 6.5 – 10.5). ECMO was initiated <72 hours in 6 patients, with survival to discharge 67%, compared to 20% in those initiated >72 hours. Overall survival to discharge was 45%, and was higher with VV ECMO (64%), than other configurations (25%).Conclusion ECMO was rarely used in major trauma, the most common indication being severe hypoxaemic respiratory failure secondary to lung injury. In this severely injured cohort, overall survival was poor but better in VV compared to VA and better if initiated early (<72 hours), compared to late.

The novel Mechanical Ventilator Milano for the COVID-19 pandemic.

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Use of Either Non-invasive Ventilation Immediately Post-extubation or Controlled Mechanical Ventilation for One Hour after Fulfilling Weaning Criteria Decreases Re-intubation of Patients with Post-traumatic ARDS

Introduction: Re-intubation and re-ventilation after complete weaning of patients with prolonged ventilation are considered a major problem in ICU. The re-intubation in such patients associated with higher mortalities prolongs the duration of ICU stay. The mortality rate in those patients may exceed 40% in some studies. Aims: The study aimed to compare and evaluate the effect of use of two new maneuvers with control after fulfilling criteria of weaning from prolonged ventilation, either immediate use of NIV post-extubation and every 12 hours for 24 hours or MV for one hour on both re-intubation and ICU discharge of traumatic ARDS patients who ventilated for one week or more. Materials and Methods: It is a prospective double-blind study done on total 300 patients, admitted with respiratory failure ARDS due to severe lung contusion. All of them were selected to be ventilated for &gt; one week. All of them fulfilled the criteria of weaning at the end of the studied period. Patients were randomly allocated in three groups; each group contained 100 patients. Group A was considered the control group. They extubated and followed our routine protocol; patients of group B used our first new maneuver and reconnected to mechanical ventilation before extubation for one hour, while patients of group C used our second new maneuver; patients of this group extubated and immediately connected to NIV with BIPAP mode for 1 hour every 12 hours for 24 hours. Results: There was a significant reduction in the number of patients who experienced deterioration in conscious level throughout the study in patients of both groups B and C compared to group A. Also, a significant reduction was seen in the number of patients who experienced deterioration in clinical parameters of respiration, of both groups B and C compared to group A with regard to high respiratory rate, desaturation and development of hyperdynamic circulation (tachycardia and hypertension). Also, a significant reduction was seen in the number of patients who had multiple quadrant parenchymatous infiltration throughout the study in patients of both groups B and C compared to group A. significant reduction in the number of patients marked limitation to FEV1, FVC and MVV in patients of both groups B and C compared to group A. Conclusion: Use of either immediate NIV every 12 hours for 24 hours or MV for one hour after fulfillment of weaning criteria reduced reintubation, re-ventilation and post-extubation respiratory failure and decreased the ICU stay in prolonged ventilated patients due to ARDS from severe lung trauma with no significant difference between them.

Fast Tracking in Off Pump CABG with Supraglottic Airway and TIVA

AbstractThe standard goals of anesthetic management for an off pump coronary artery bypass (OPCAB) surgery are that it should be safe, provide cardiac and other organ protection and stability, preserve neurocognitive integrity, maintain hemodynamics, allow early emergence and ambulation, and offer pain relief in the postoperative period. The cardiac surgical team should collaborate and plan the best preoperative strategy, so as to provide optimal care and a rapid and expeditious recovery of these patients. Scientific evidence and practical experience make total intravenous anesthesia (TIVA) the recommended choice for cardiac surgery. Use of endotracheal tube (ETT) is associated with certain drawbacks which can be overcome with judicious use of ProSeal laryngeal mask airway (PLMA) for cardiac surgeries too. The core principles of ultrafast track anesthetic (UFTA) technique are choice and titration of short-acting anesthetic drugs, postoperative normothermia, multimodal analgesia, early extubation, ambulation, and discharge. Fast tracking with use of TIVA and PLMA in patients undergoing OPCAB at our center offers certain advantages over other techniques in terms of reduced airway and lung trauma, improved cardiac output and renal perfusion with spontaneous respiration, decreased stress and discomfort of ETT suctioning and weaning from ventilation, substantially reduced requirement of dosages of analgesics, anesthetics and opioids, resulting in better patient hemodynamics, alert and pain-free patient that are more amenable and cooperative for early feeds, postoperative chest physiotherapy and lung recruitment strategies, and early ambulation and discharge.

Sodium butyrate relieves lung ischemia-reperfusion injury by inhibiting NF-κB and JAK2/STAT3 signaling pathways.

Ischemia-reperfusion (IR) is the main cause of acute lung injury (ALI) in clinical lung transplantation, extracorporeal circulation, lung sleeve resection, trauma and cardiopulmonary resuscitation. The inflammatory response and oxidative stress following IR are factors that cause and aggravate its secondary damage. The purpose of this study was to investigate the efficacy and mechanism of sodium butyrate (NaB) on lung ischemia-reperfusion injury (LIRI). We used male C57BL/6 mice to construct the LIRI model and administered the mice with NaB. By examining the expression of inflammatory factors and oxidative stress-related molecules in mouse lung tissue, we investigated the effects of NaB on inflammation and oxidative stress in lung tissue after IR. In addition, the changes in the activity of the NF-κB and JAK2/STAT3 signaling pathways were also examined to determine the mechanism of NaB. The expression levels of the inflammatory factors (IL-1β, IL-6 and TNF-α) in lung tissue of mice after IR were significantly increased, while NaB reduced the expression of inflammatory factors. In addition, the oxidative stress level of mouse lung tissue after IR increased significantly, showing the decrease of antioxidant molecules SOD1/2, catalase (CAT), and Peroxiredoxin 1 (Prdx1), while the intake of NaB increased the antioxidant level of mouse lung tissue. The activities of NF-κB and JAK2/STAT3 signaling pathways were significantly increased in lung tissue after IR, whereas NaB inhibited the activity of NF-κB and JAK2/STAT3 signaling pathways. NaB relieves LIRI by inhibiting NF-κB and JAK2/STAT3 signaling pathways to reduce inflammation and oxidative stress levels in lung tissue of mice after IR.

Traumatic ventricular and lung perforations: Nail gun attempted suicide.

The authors declare that there are no conflict of interests. Data sharing is not applicable to this article as no new data were created or analyzed in this study.

In Search of Evidence for Using Noninvasive Ventilation for Severe Acute Asthma.

* Abbreviations: IMV — : invasive mechanical ventilation NIV — : noninvasive ventilation Noninvasive ventilation (NIV) is appealing for the treatment of severe asthma because it likely avoids the potential airway and lung trauma of intubation and invasive mechanical ventilation (IMV). In this issue of Pediatrics , Smith et al1 illustrate the compelling appeal of NIV in clinical use, showing that centers with high use of NIV in 2014 doubled their use of NIV in the next 4 years and that NIV is more common as a mode of respiratory support than IMV. … Address correspondence to Michael D. Johnson, MD, MS, Primary Children’s Hospital, 100 N Mario Capecchi Dr, Salt Lake City, UT 84108. E-mail: mike.johnson{at}hsc.utah.edu

Influence of Obesity on the Organization of the Extracellular Matrix and Satellite Cell Functions After Combined Muscle and Thorax Trauma in C57BL/6J Mice.

Obesity has been described as a major factor of health risk in modern society. Next to intricately linked comorbidities like coronary artery disease or diabetes, an influence of obesity on regeneration after muscle injury has been described previously. However, the influence of obesity on tissue regeneration in a combined trauma, merging the more systemic influence of a blunt lung trauma and the local blunt muscle trauma, has not been investigated yet. Therefore, the aim of this study was to investigate the influence of obesity on regeneration in a mouse model that combined both muscle and thorax trauma. Using gene expression analysis, a focus was put on the structure as well as the organization of the extracellular matrix and on functional satellite cell physiology. An increased amount of debris in the lung of obese mice compared to normal weight mice up to 192 h after combined trauma based on visual assessment can be reported which is accompanied by a decreased response of Mmp2 in obese mice. Additionally, a delayed and elongated response of inhibitor genes like Timp1 has been revealed in obese mice. This elongated response to the trauma in obese mice can also be seen in plasma based on increased levels of pro-inflammatory chemo- and cytokines (IL-6, MCP-1, and IL 23) 192 h post trauma. In addition to changes in the lung, morphological analysis of the injured extensor iliotibialis anticus of the left hind leg in lean and diet-induced obese mice revealed deposition of fat in the regenerating muscle in obese animals hindering the structure of a compact muscle. Additionally, decreased activation of satellite cells and changes in organization and build-up of the ECM could be detected, finally leading to a decreased stability of the regenerated muscle in obese mice. Both factors contribute to an attenuated response to the trauma by obese mice which is reflected by a statistically significant decrease in muscle force of obese mice compared to lean mice 192 h post trauma induction.

Horner Syndrome With Ipsilateral Wing Paresis in a Wild, Juvenile Yellow-Tailed Black Cockatoo (Calyptorhynchus funereus)

A juvenile yellow-tailed black cockatoo (Calyptorhynchus funereus) was presented with paresis of the right wing, ptosis, and miosis of the right eye; feather erection of the right side of the head and neck; and a penetrating injury over the right pectoral muscle. Temporary reversal of ptosis, miosis, and feather erection after administration of phenylephrine drops confirmed a diagnosis of Horner syndrome. Computed tomographic imaging revealed a fractured rib, traumatic lung lesions, and subcutaneous emphysema. The right-sided Horner syndrome and wing paresis were attributed to a sympathetic nerve trauma of the eye and feathers and to the brachial plexus, respectively. This report describes the diagnosis and resolution of ptosis and miosis within 8 weeks and recovery of feather symmetry and wing function within 11 weeks of the cockatoo's initial presentation with a conservative-management treatment plan.

Seatbelt-induced extrathoracic lung herniation.

Traumatic lung herniation is an uncommon complication of blunt chest trauma due to seatbelt injury. High index of suspicion, adherence to ATLS guidelines, and cooperation between different surgical specialties for the prompt stabilization of flail chest and primary or prosthetic closure of the defect may ensure a favorable outcome.

Clinical outcomes of extracorporeal membrane oxygenation in acute traumatic lung injury: a retrospective study

BackgroundTherapeutic extracorporeal membrane oxygenation (ECMO) is a challenging procedure in patients who have experienced severe trauma. Particularly, patients with traumatic lung injury and posttraumatic acute respiratory distress syndrome (ARDS) have a high risk of bleeding during this procedure. This study aimed to determine the safety and feasibility of ECMO in patients with traumatic ARDS.MethodsWe retrospectively reviewed medical records and investigated the clinical outcomes of ECMO in 42 patients with traumatic ARDS, among whom near-drowning (42.9%) was the most frequent cause of injury.ResultsThirty-four of 42 patients (81%) survived and were discharged after a median hospital stay of 23 days. A multivariate analysis identified a lactate level (odds ratio: 1.493, 95% confidence interval: 1.060–2.103, P = 0.022) and veno-venous (VV) ECMO (odds ratio: 0.075, 95% confidence interval: 0.006–0.901, P = 0.041) as favorable independent predictors of survival in patients with traumatic ARDS who underwent ECMO. The optimal cut off value for pre-ECMO lactate level was 10.5 mmol/L (area under the curve = 0.929, P = 0.001). In Kaplan-Meier analysis, the survival rate at hospital discharge was significant higher among the patients with a pre-ECMO lactate level of 10.5 mmol/L or less compared with patients with pre-ECMO lactate level greater than 10.5 mmol/L (93.8% versus 40.0%, respectively; P = 0.01).ConclusionsECMO yielded excellent survival outcomes, particularly in patients with low pre-treatment lactate levels who received VV ECMO. Therefore, ECMO appears safe and highly feasible in a carefully selected population of trauma patients.

Mesenchymal stem cell use in acute respiratory distress syndrome: a potential therapeutic application.

Acute respiratory distress syndrome (ARDS) is a condition of acute respiratory failure resulting from noncardiogenic pulmonary edema. It may occur as a consequence of lung infection, sepsis, trauma, aspiration or drug reaction. The pathogenesis of ARDS is understood to be an unregulated inflammatory cascade with both endothelial and epithelial layer damage leading to alveolar fluid collection and pulmonary edema. Despite improved understanding of the cause of ARDS, treatment remains supportive with a mortality rate ranging from 25–40%. Preclinical and early phase clinical trials have highlighted the potential role of mesenchymal stem cells in combating the inflammatory cascade through immunomodulatory mechanisms and assisting in tissue repair.

Microarray and bioinformatics analysis of circular RNAs expression profile in traumatic lung injury

Acute lung injury (ALI) and respiratory distress syndrome are common, potentially lethal injuries that predominantly occur following chest trauma. Circular RNAs (circRNAs) are stable conserved non-coding RNAs that are widely expressed in different organs. To the best of our knowledge, no previous studies have shown whether circRNAs are involved in traumatic lung injury (TLI). The aim of the present study was to identify highly expressed circRNAs in plasma samples from patients with TLI and explore their potential functions in the pathogenesis of TLI. A high-throughput circRNA microarray was used to investigate the expression profile of circRNAs in plasma samples from five patients with TLI and paired control samples. Subsequently, a total of five abnormally expressed circRNAs were investigated using reverse transcription-quantitative PCR (RT-qPCR). A bioinformatics analysis was performed to predict a competitive endogenous RNA (ceRNA) network. In addition, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to identify the main biological processes and pathways. Finally, additional samples were tested to identify the expression profiles of the selected circRNAs. Among the 310 circRNAs that were highly expressed in the microarray analysis, 60 were upregulated and 250 were downregulated in patients with TLI. RT-qPCR results indicated that two downregulated circRNAs (circ_102927 and circ_100562) and one upregulated circRNA (circ_101523) matched the microarray results. The bioinformatics analysis constructed a targeting network based on the three validated circRNAs. GO and KEGG analyses identified the top ten enriched annotations. The expression of homo sapiens circular RNA 102927 (hsa_circRNA_102927) in the plasma of patients with TLI was 0.34-fold compared with the control group in expanded size validation. The results of the present study identified the differentially expressed circRNAs in the plasma of patients with TLI and provided evidence that highly expressed circRNAs involved in the ceRNA network may serve a role in the pathophysiology of TLI.