Lung injury and acute respiratory distress syndrome after cardiopulmonary bypass

Biomarkers of inflammation and coagulation after minimally invasive mitral valve surgery: a prospective comparison to conventional surgery

OBJECTIVES

Minimally invasive cardiac surgery techniques are increasingly used but have longer cardiopulmonary bypass time, which may increase inflammatory response and negatively affect coagulation. Our aim was to compare biomarkers of inflammation and coagulation as well as transfusion rates after minimally invasive mitral valve repair and mitral valve surgery using conventional sternotomy.

DESIGN

A prospective non-randomized study was performed enrolling 71 patients undergoing mitral valve surgery (35 right mini-thoracotomy and 36 conventional sternotomy procedures). Blood samples were collected pre- and postoperatively to assess inflammatory response. Thromboelastometry (ROTEM) was performed to assess coagulation, and transfusion rates were monitored.

RESULTS

The minimally invasive group had longer cardiopulmonary bypass times compared to the sternotomy group: 127 min ([115-146] vs 79 min [65-112], p < 0.001) and were cooled to a lower temperature during cardiopulmonary bypass, 34 °C vs 36 °C (p = 0.04). IL-6 was lower in the minimally invasive group compared to the conventional sternotomy group when measured at the end of the surgical procedure, (38 [23-69] vs 61[41-139], p = 0.008), but no differences were found at postoperative day 1 or postoperative day 3. The transfusion rate was lower in the minimally invasive group (14%) compared to full sternotomy (35%, p = 0.04) and the chest tube output was reduced, (395 ml [190-705] vs 570 ml [400-1040], p = 0.04).

CONCLUSIONS

Our data showed that despite the longer use of extra corporal circulation during surgery, minimally invasive mitral valve repair is associated with reduced inflammatory response, lower rates of transfusion, and reduced chest tube output.

Perioperative sildenafil therapy in pulmonary hypertension associated with congenital cardiac disease: An updated meta-analysis

To provide an updated meta-analysis to evaluate the efficacy and safety of sildenafil on pediatric patients with pulmonary hypertension (PH) associated with congenital heart disease (CHD). To assess the efficacy and safety of sildenafil, five outcomes, time duration of post-operative need for mechanical ventilation, time duration of post-operative ICU stay, length of hospitalization (LOH), the incidence of mortalities and pulmonary arterial pressure to aortic pressure ratio (PAP/AoP) were regarded as primary efficacy outcomes. Standardized mean difference (SMD) was calculated for continuous data. In comparison to the control group (CG), there was a significant decrease in the time duration of ICU stay in the sildenafil group (SG) (SMD = -0.61 [95% CI -1.17, 0.04]; P < 0.01, I2 = 85%). Length of hospitalization was assessed in the sildenafil and control groups (SMD = -0.18 [95% CI -0.67, 0.31] P = 0.05, I2 = 62%). However, there was no significant difference seen in mortality rates between the SG and CG (SMD = 0.53 [ 95% CI 0.13, 2.17] p = 0.61, I2 = 0%), in the time duration of postoperative mechanical ventilation between the SG and CG (SMD = -0.23 [95% CI -0.49, 0.03] p = 0.29, I2 = 19%), or PAP/AoP ratio between the SG and CG (SMD = -0.42 [95% CI -1.35, 0.51] P < 0.01, I2 = 90%). Based on our analysis, sildenafil has little to no effect in reducing postoperative morbidity and mortality due to PH in infants and children with CHD.

Thoracoabdominal aortic aneurysmectomy in the high-risk patient

OBJECTIVE

The study objective was to provide a review of outcomes and management strategies for high-risk scenarios in the open repair of thoracoabdominal aortic aneurysms.

METHODS

Series examining the open repair of thoracoabdominal aortic aneurysms were reviewed to identify well-described high-risk scenarios and summarize expected outcomes and management strategies in the current era.

RESULTS

The efforts of many have led to improved outcomes for patients undergoing the inherently challenging open repair of thoracoabdominal aortic pathologies. Several well-described high-risk scenarios include those related to preoperative comorbid conditions (preoperative pulmonary dysfunction, low ejection fraction, and renal dysfunction), anatomically high-risk cases (extent II repairs), and those with acute presentations (rupture, mycotic aneurysms, acute complicated type B aortic dissection). Several operative and perioperative techniques have been developed to mitigate the risk in these formidable cases.

CONCLUSIONS

Challenges remain for several high-risk scenarios in thoracoabdominal aortic aneurysm repair. Judicious patient selection, meticulous surgical, and critical care strategies have greatly decreased the risk for many high-risk patients.

Postoperative hyper-inflammation as a predictor of poor outcomes in patients with acute type A aortic dissection (ATAAD) undergoing surgical repair

BACKGROUND

Postoperative hyper-inflammation is a frequent event in patients with acute Stanford type A aortic dissection (ATAAD) after surgical repair. This study's objective was to determine which inflammatory biomarkers could be used to make a better formula for identifying postoperative hyper-inflammation, and which risk factors were associated with hyper-inflammation.

METHODS

A total of 405 patients were enrolled in this study from October 1, 2020 to April 1, 2023. Of these patients, 124 exhibited poor outcomes. In order to investigate the optimal cut-off values for poor outcomes, logistic and receiver operating characteristic analyses were performed on the following parameters on the first postoperative day: procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6), and systemic immune-inflammation index (SII). These cut-off points were used to separate the patients into hyper-inflammatory (n = 52) and control (n = 353) groups. Finally, the logistic were used to find the risk factors of hyper-inflammatory.

RESULTS

PCT, CRP, IL-6, and SII were independent risk factors of poor outcomes in the multivariate logistic model. Cut-off points of these biomarkers were 2.18 ng/ml, 49.76 mg/L, 301.88 pg/ml, 2509.96 × 109/L respectively. These points were used to define postoperative hyper-inflammation (OR 2.97, 95% CI 1.35-6.53, P < 0.01). Cardiopulmonary bypass (CPB) > 180 min, and deep hypothermia circulatory arrest (DHCA) > 40 min were the independent risk factors for hyper-inflammation.

CONCLUSIONS

PCT > 2.18, CRP > 49.76, IL-6 > 301.88, and SII < 2509.96 could be used to define postoperative hyper-inflammation which increased mortality and morbidity in patients after ATAAD surgery. Based on these findings, we found that CPB > 180 min and DHCA > 40 min were separate risk factors for postoperative hyper-inflammation.

Mean Arterial Pressure (MAP) Trial: study protocol for a multicentre, randomized, controlled trial to compare three different strategies of mean arterial pressure management during cardiopulmonary bypass

BACKGROUND

One of the main goals of cardiopulmonary bypass (CPB) is targeting an adequate mean arterial pressure (MAP) during heart surgery, in order to maintain appropriate perfusion pressures in all end-organs. As inheritance of early studies, a value of 50-60 mmHg has been historically accepted as the "gold standard" MAP. However, in the last decades, the CPB management has remarkably changed, thanks to the evolution of technology and the availability of new biomaterials. Therefore, as highlighted by the latest European Guidelines, the current management of CPB can no longer refer to those pioneering studies. To date, only few single-centre studies have compared different strategies of MAP management during CPB, but with contradictory findings and without achieving a real consensus. Therefore, what should be the ideal strategy of MAP management during CPB is still on debate. This trial is the first multicentre, randomized, controlled study which compares three different strategies of MAP management during the CPB.

METHODS

We described herein the methodology of a multicentre, randomized, controlled trial comparing three different approaches to MAP management during CPB in patients undergoing elective cardiac surgery: the historically accepted "standard MAP" (50-60 mmHg), the "high MAP" (70-80 mmHg) and the "patient-tailored MAP" (comparable to the patient's preoperative MAP). It is the aim of the study to find the most suitable management in order to obtain the most adequate perfusion of end-organs during cardiac surgery. For this purpose, the primary endpoint will be the peak of serum lactate (Lmax) released during CPB, as index of tissue hypoxia. The secondary outcomes will include all the intraoperative parameters of tissue oxygenation and major postoperative complications related to organ malperfusion.

DISCUSSION

This trial will assess the best strategy to target the MAP during CPB, thus further improving the outcomes of cardiac surgery.

TRIAL REGISTRATION

NCT05740397 (retrospectively registered; 22/02/2023).

In vitro and in vivo biological evaluation of Lappaconitine derivatives as potential anti-inflammatory agents

Natural products and their derivatives are a precious treasure in the pursuit of potent anti-inflammatory drugs. In this work, we measured the toxicity of 78 LA derivatives at 20 μM using MTT, then we evaluated the NO release of compounds without obvious toxicity in LPS-induced RAW.264.7 by Griess reagent, we identified three compounds, namely compounds 6, 19, 70, which exhibited promising anti-inflammatory potential. These compounds exhibited IC50 values of 10.34±2.05 μM, 18.18±4.80 μM and 15.66±0.88 μM. In addition, through ELISA kits, compounds 6, 19, 70 significantly reduce the production of inflammatory factors (TNF-α, IL-6, IL-1β). Real-time PCR and western blot analysis showed that compounds 6, 19, 70 inhibited the mRNA and protein expression of iNOS and COX-2. Notably, compound 6 exhibited the most potent inhibitory activity. In vitro, it inhibits LPS-induced phosphorylation of NF-κB p65, IκBα, ERK1/2, JNK, and p38 MAPKs in RAW264.7 cells. In vivo, compound 6 potently inhibits the secretion of inflammatory mediators and neutrophil activation in ALI mice. Our findings suggest that compound 6 may be a potential anti-inflammatory drug.

sTREM2 in the prognostic evaluation of acute lung injury after cardiac surgery in infants

BACKGROUND

Previous studies have shown that TREM2 plays a protective role in acute lung injury (ALI). This prospective study aimed to investigate the role of sTREM2 as a forecasting factor for ALI in infants after pediatric cardiac surgery undergoing cardiopulmonary bypass (CPB).

METHODS

Seventy-five consecutive patients younger than 1 year who underwent cardiac surgery were enrolled in this study. Sixty-one fulfilled the inclusion criteria and had been divided into ALI and non-ALI groups. Children's demographic characteristics and clinical data were collected. Perioperative sTREM2 levels were analyzed at five timepoints.

RESULTS

In this study, children in the ALI group were younger, lighter, with higher RACHS-1 scores and underwent significantly longer CPB time. Post-CPB ALI had an impact on clinical outcomes, which contributed to a longer duration of mechanical ventilation, ICU and hospital stay than non-ALI group. Significant differences were manifested off-CPB, 1 h/6 h after CPB, and day 1 after surgery between the two groups. Binary logistic models revealed that off-CPB sTREM2 was significantly associated with the incidence of post-CPB ALI after adjustment. ROC analysis showed that the AUC of off-CPB sTREM2 level was 0.791, and the optimal cutoff value was 788.6 pg/ml.

CONCLUSIONS

The off-CPB sTREM2 level was an independent prognostic factor for post-CPB ALI in infants.

IMPACT

Plasma sTREM2 works together with downstream TREM2 to regulate inflammation response by binding the receptor to other cells. Previous studies have shown that TREM2 plays a protective role in ischemia-reperfusion and has anti-inflammatory effects on acute lung injury (ALI). This study analyzed the risk factors of post-cardiopulmonary bypass (CPB) ALI. We found that weight and off-CPB sTREM2 level were independent prognostic factors for post-CPB ALI. Plasma sTREM2 may serve as an early biomarker in the prognostic evaluation of acute lung injury after cardiac surgery in infants.

Sivelestat in Patients at a High Risk of Postoperative Acute Lung Injury After Scheduled Cardiac Surgery: A Prospective Cohort Study

Background

Sivelestat, a neutrophil elastase inhibitor, is specifically developed to mitigate the occurrence of acute lung injury (ALI) in individuals who are undergoing cardiovascular surgery. However, its impact on patients who are at a heightened risk of developing ALI after scheduled cardiac surgery has yet to be determined. In order to address this knowledge gap, we undertook a study to assess the efficacy of sivelestat in protecting the lungs of these patients.

Methods

We conducted a prospective cohort study involving 718 patients who were at high risk of developing postoperative acute lung injury (ALI) and underwent scheduled cardiac surgery between April 25th, 2022, and September 7th, 2023. Among them, 52 patients received sivelestat (administered at a dosage of 0.2mg/kg/h for 3 days), while 666 patients served as controls, not receiving sivelestat. The control conditions were the same for all patients, including ventilation strategy, extubating time, and fluid management. Subsequently, a propensity-score matched cohort was established, consisting of 40 patients in both the sivelestat and control groups. The primary outcome measure encompassed a composite of adverse outcomes, including 30-day mortality, ALI, acute respiratory distress syndrome (ARDS), and others. Secondary outcomes assessed included pneumonia, ventricular arrhythmias, mechanical ventilation (MV) time, and more.

Results

After conducting propensity matching in our study, we observed that there were no significant differences in 30-day mortality between the sivelestat and control groups (0% vs 2.5%, P=0.32). However, the use of sivelestat exhibited a significant reduction in the incidence of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) compared to the control group (0% vs 55%, P<0.01), pneumonia (0 vs 37.5%, P<0.01), MV time (median:8 hours, IQR:4-14.8 hours vs median: 15.2 hours, IQR:14-16.3 hours, P<0.01). Compared to the control group, the sivelestat could significantly decrease white cell count (P<0.01), neutrophile percentage (P<0.01) and C-reactive protein (P<0.01) in the period of postoperative 5 days.

Conclusion

The prophylactic administration of sivelestat has shown promising results in reducing the occurrence of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in patients with a heightened risk of developing these conditions after elective cardiac surgery. Our study findings indicate that sivelestat may provide protective effects by suppressing inflammation triggered by neutrophil activation, thereby safeguarding pulmonary function.

Registration

ChiCTR2200059102, https://www.chictr.org.cn/showproj.html?proj=166643.

Anesthetic Management of a Patient With Massive Pulmonary Secretion During Cardiopulmonary Bypass Probably Due to Transfusion-Related Acute Lung Injury Type Ⅱ

Transfusion-related acute lung injury (TRALI) is potentially life-threatening adverse reaction associated with blood transfusion and can induce perioperative pulmonary secretion. TRALI that develops during cardiopulmonary bypass (CPB) may be difficult to detect; however, the pathophysiology might manifest as derangements in CPB operations. A 79-year-old man was scheduled to undergo partial replacement of the aortic arch with CPB. Two units of red blood cells were loaded into the priming solution. Although the vital signs, including oxygenation, remained stable in the prebypass period, perfusionists noticed a decreasing trend in the venous reservoir level early in the CPB operations. The trend continued even during circulatory arrest with selective cerebral perfusion, resulting in the termination of the modified hemofiltration. Surgical procedures were accomplished uneventfully; however, a large amount of fluid was required to maintain the minimal reservoir level and CPB flow. The total fluid balance during CPB was +8,233 mL, which was quite unusual in our practice. When 800 mL of massive pulmonary secretion was detected before CPB withdrawal, the etiology could not be determined simultaneously; nonetheless, systemic vascular hyperpermeability was speculated to be the underlying pathophysiology. Our therapeutic approach following the treatment of acute respiratory distress syndrome contributed to halting the deterioration of lung injury. Although the pneumothorax developed on the first postoperative day, the patient was treated with the insertion of a chest drainage tube. Subsequently, the patient had a good course and was discharged without respiratory complications. In conclusion, massive pulmonary secretion, probably due to TRALI type II, was associated with derangements in CPB operations. Prompt identification of the underlying pathophysiology and appropriate intervention is crucial.

Myeloid Progenitor Inhibitory Factor-1 (CCL23) Inhibits Lung Leukocyte Recruitment in a Primate Cardiopulmonary Bypass-Induced Pulmonary Ischaemia Model

BACKGROUND

Bone marrow (BM)-derived polymorphonuclear leukocytes (PMNs) and monocytes (MO) induced by cardiopulmonary bypass (CPB) are highly proteolytic and cause postoperative lung injury. Although CCL23/Myeloid progenitor inhibitory factor-1 is a human CC chemokine with potent suppressor effects on myeloid progenitor cells, in vivo inhibitory effects on BM-derived leukocyte kinetics associated with CPB are unknown.

METHODS

Two-hour CPB was surgically performed in cynomolgus monkeys and BM-derived leukocytes kinetics were monitored postoperatively by flow cytometry with 5'-bromo-2'-deoxyuridine (BrdU) and cytokine ELISA. Monkeys were given CCL23 (n=5) or saline (control, n=5) intravenously daily for 3 days before BrdU labelling and peripheral blood/bronchoalveolar lavage fluid (BALF) timepoint sampling to reveal BrdU-labelled cells. Levels of cytokines, CD11b, and L-selectin were considered leukocytic activation markers.

RESULTS

The CCL23 treatment significantly prolonged BM transit of leukocytes (PMNs, 118.4±11.7-95.5±4.1 hours [control]; MO, 91.6±5.0-62.0±3.0 hours [control]) and reduced their alveolar appearance. The BM pool size of MO was decreased by CCL23 but PMNs were unaffected. CD11b, L-selectin expression of PMNs and MO during CPB, and post-surgical increases of interleukin (IL)-6, IL-8, TNF-α, MCP-1, and PMN elastase in the BALF were not suppressed.

CONCLUSIONS

CCL23 treatment slows turnover of PMN and MO progenitors in BM and suppresses their circulatory release and lung recruitment. CCL23 has inhibitory effects specifically on the CPB-induced BM response and could hold value for preventing CPB-induced lung injury.

Ex-situ oxygenated hypothermic machine perfusion in donation after circulatory death heart transplantation following either direct procurement or in-situ normothermic regional perfusion

BACKGROUND

Heart transplantation in donation after circulatory death (DCD) relies on warm perfusion using either in situ normothermic regional perfusion (NRP) or ex situ normothermic machine perfusion. In this study, we explore an alternative: oxygenated hypothermic machine perfusion (HMP) using a novel clinically applicable perfusion system, which is compared to NRP with static cold storage (SCS).

METHODS

In a porcine model, a DCD setting was simulated, followed by either (1) NRP and SCS (2) NRP and HMP with the XVIVO Heart preservation system or (3) direct procurement (DPP) and HMP. After preservation, heart transplantation (HTX) was performed. After weaning from cardiopulmonary bypass (CPB), biventricular function was assessed by admittance and Swan-Ganz catheters.

RESULTS

Only transplanted hearts in the HMP groups showed significantly increased biventricular contractility (end-systole elastance) 2 hour post-CPB (left ventricle absolute change: NRP HMP: +1.8 ± 0.56, p = 0.047, DPP HMP: +1.5 ± 0.43, p = 0.045 and NRP SCS: +0.97 ± 0.47 mmHg/ml, p = 0.21; right ventricle absolute change: NRP HMP: +0.50 ± 0.12, p = 0.025, DPP HMP: +0.82 ± 0.23, p = 0.039 and NRP SCS: +0.28 ± 0.26, p = 0.52) while receiving significantly less dobutamine to maintain a cardiac output >4l/min compared to SCS. Diastolic function was preserved in all groups. Post-HTX, both HMP groups showed significantly less increments in plasma troponin T compared to SCS.

CONCLUSION

In DCD HTX, increased biventricular contractility post-HTX was only observed in hearts preserved with HMP. In addition, the need for inotropic support and signs of myocardial damage were lower in the HMP groups. DCD HTX can be successfully performed using DPP followed by preservation with HMP in a preclinical setting.

The neutrophil elastase inhibitor, sivelestat, attenuates acute lung injury in patients with cardiopulmonary bypass

Background

The sivelestat is a neutrophil elastase inhibitor thought to have an effect against acute lung injury (ALI) in patients after scheduled cardiac surgery. However, the beneficial effect of sivelestat in patients undergoing emergent cardiovascular surgery remains unclear. We aim to evaluate the effect of sivelestat on pulmonary protection in patients with ALI after emergent cardiovascular surgery.

Methods

Firstly, a case-control study in 665 patients undergoing emergent cardiovascular surgery from January 1^st, 2020 to October 26^th, 2022 was performed. 52 patients who received sivelestat (0.2mg/kg/h for 3 days) and 613 age- and sex-matched controls. Secondly, a propensity-score matched cohort (sivelestat vs control: 50 vs 50) was performed in these 665 patients. The primary outcome was a composite of adverse outcomes, including 30-day mortality, ECMO, continuous renal replacement therapy (CRRT) and IABP, etc. The secondary outcome included pneumonia, ventricular arrhythmias and mechanical ventilation time, etc.

Results

In propensity-matched patients, the 30-day mortality (16% vs 24%, P=0.32), stroke (2% vs 8%, P=0.17), ECMO(6% vs 10%, P=0.46), IABP(4% vs 8%, P=0.40) and CRRT(8% vs 20%, P=0.08) had no differences between sivelestat and control group; sivelestat could significantly decrease pneumonia (40% vs 62%, P=0.03), mechanical ventilation time (median: 96hours, IQR:72-120hours vs median:148hours, IQR:110-186hours, P<0.01), bilateral pulmonary infiltrates (P<0.01), oxygen index (P<0.01), interleukin-6(P=0.02), procalcitonin(P<0.01) and C-reactive protein(P<0.01).

Conclusion

Administration of sivelestat might improve postoperative outcomes in patients with ALI after emergent cardiovascular surgery. Our results show that sivelestat may be considered to protect pulmonary function against inflammatory injury by CPB.

Registration

http://www.chictr.org.cn/showproj.aspx?proj=166643, identifier ChiCTR2200059102.

CARDIOPULMONARY BYPASS-DERIVED PLASMA EXOSOMAL HMGB1 CONTRIBUTES TO ALVEOLAR EPITHELIAL CELL NECROPTOSIS VIA mtDNA/CGAS/STING PATHWAY

ABSTRACT

Our previous study confirmed that cardiopulmonary bypass (CPB) leads to acute lung injury (ALI) via inducing high-mobility group box 1 (HMGB1) release. Recent research showed that HMGB1 promotes pulmonary injury mainly via exosomes transport. Currently, alveolar epithelial cell (AEC) necroptosis has been demonstrated to be involved in ALI. However, it is unknown whether exosomal inflammatory cytokine HMGB1 promotes ALI by inducing AEC necroptosis, and its underlying mechanisms remain elusive. Here, a prospective cohort study was carried out, in which plasma samples from 21 CPB patients were isolated at four specific time points: pre-CPB, 2, 12, and 24 h after initiation of CPB. Plasma exosomes were extracted via ultra-high-speed centrifugation and cocultured with AEC cell line-A549 cells at increasing concentrations of 50, 100, and 150 μg/mL. Then, HMGB1 antagonist-Box A and mtDNA deficiency ethidium bromide (EtBr) were applied to explore the underlying role of exosomal HMGB1 and cytoplasm mitochondrial DNA in AEC. Western blot analysis showed that plasma exosomal HMGB1 expression gradually increased and peaked at 24 h after CPB. Twenty-four-hour treatment of CPB-derived exosomes at 150 μg/mL for 24 h could induce necroptosis by promoting mitochondrial fission and further elevating cytoplasm mtDNA levels in A549 cells, which was successfully blocked by Box A or EtBr. Most importantly, EtBr significantly inhibited cytoplasm mtDNA downstream guanosine monophosphate (GMP)-AMP synthase (cGAS)/stimulator of interferon gene (STING) signal pathway. Collectively, these data demonstrate that CPB-derived plasma exosomal HMGB1 contributes to AEC necroptosis through the mtDNA/cGAS/STING pathway.

Cell saver blood transfusions may be associated with a decrease in inflammation and improved outcome measures in pediatric cardiac surgery patients

OBJECTIVE

Cardiopulmonary bypass (CPB) is a requisite for correction of congenital heart disease by open-heart surgery and induces a systemic inflammatory response that can lead to complications such as acute lung injury and acute kidney injury. In addition, blood transfusions are commonly required for this type of surgery, and they may further exacerbate this inflammatory response and increase morbidity and mortality. We hypothesized that, in contrast to red blood cells, intraoperative cell saver (CS) blood transfusions attenuate the post-CPB proinflammatory cytokine response.

METHODS

Serum cytokine concentrations of IL-10, IL-1RA, IL-6, IL-8, and TNF-α were measured at four time points (preoperatively and postoperatively on postoperative days 0, 1, and 2).

RESULTS

Anti-inflammatory IL-10 levels were significantly lower in the CS group on POD 0 than in the control group (mean 1083.2 pg/mL vs 2080.2 pg/mL, 95%CI 357.4-1636.6, p = .0026). Of the clinical parameters measured, mean BUN and creatinine levels on POD 2 were significantly lower in the CS group (13.79 vs 21.88, p = .004 and 0.45 vs 0.55, p = .055, respectively). In addition, the duration of milrinone use decreased by 80% in the CS group (0.20, 95%CI 0.04, 0.94; p = .048), the median time to extubation in hours was significantly lower in the CS group (3.5 vs 6.5; 95%CI -38.00, -0.50; p = .026), and hospital length of stay was decreased by 60% in the CS group (p = .003).

CONCLUSIONS

CS transfusions in children may lower postoperative anti-inflammatory IL-10 levels, possibly due to an overall decrease in proinflammatory state, and may be associated with improvements in renal and pulmonary functions.

Unilateral pulmonary edema associated factors after minimally invasive mitral valve surgery

BACKGROUND AND OBJECTIVES

In recent years, minimally invasive cardiac surgery (MICS) has been developed and applied to a greater number of pathologies, especially in mitral valve surgeries, as it obtains results comparable to those of conventional techniques while entailing lower surgical trauma and shorter recovery time. MICS requiring one-lung ventilation has been associated to the appearance of unilateral pulmonary edema (UPE), which is a potentially serious complication. The objective is determining the incidence of UPE after mitral MICS and its development associated factors.

MATERIAL AND METHODS

Observational descriptive and single-center study analyzing data from patients undergoing mitral valve MICS (right mini-thoracotomy) consecutively collected between the years 2015 and 2017.

RESULTS

A total of 93 patients were included and 26 presented UPE. The most common complications after mitral valve MICS were atrial fibrillation (38.7%), UPE (28%) and transient and/or definitive second- or third-degree auriculoventricular block (19.4%). The UPE group had longer ICU stay (3.3 ± 8.0 vs. 1.84 ± 2.23 days) and longer total hospitalization length-of-stay (15.5 ± 34.7 vs. 10.6 ± 7.5 days). The mortality in the UPE group was 3.9%. A significant association was found between the following collected variables and the development of postoperative UPE: preoperative baseline pulse oximetry, preoperative use of ACE inhibitors, postoperative atrial fibrillation and 24 first-hours cumulative chest tube drainage volume on the first 24 h.

CONCLUSIONS

The incidence of UPE is high and its appearance is associated with a longer ICU and total length of stay. More studies are required to understand its pathophysiology and apply measures to help decreasing its appearance.

Cardiac surgery outcomes in patients with coronavirus disease 2019 (COVID-19): A case-series report

OBJECTIVE

The impact of coronavirus disease 2019 (COVID-19) on the postoperative course of patients after cardiac surgery is unknown. We experienced a major severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in our cardiac surgery unit, with several patients who tested positive early after surgery. Here we describe the characteristics, postoperative course, and laboratory findings of these patients, along with the fate of the health care workers. We also discuss how we reorganize and reallocate hospital resources to resume the surgical activity without further positive patients.

METHODS

After diagnosis of the first symptomatic patient, surgery was suspended. Nasopharyngeal swabs were performed in all patients and health care workers. Patients who were positive for SARS-CoV-2 were isolated and monitored throughout the in-hospital stay and followed up after discharged until death or clinical recovery.

RESULTS

Twenty patients were found to be positive for SARS-CoV-2 sometime after cardiac surgery (mean age 69 ± 10.4 years; median European System for Cardiac Operative Risk Evaluation II score 3 [interquartile range, 5.1]); the median time from surgery to diagnosis was 15 days (interquartile range, 11). Among the patients, 18 had undergone cardiac surgery and 2 of them transcatheter aortic valve replacement. Overall mortality was 15%. Specific COVID-19-related symptoms were identified in 7 patients (35%). Among the 12 health care workers infected, 1 developed a bilateral mild-grade interstitial pneumonia.

CONCLUSIONS

COVID-19 infection after cardiac surgery, regardless the time of the onset, is a serious condition. The systemic inflammatory state that follows extracorporeal circulation may mask the typical COVID-19 laboratory findings, making the diagnosis more difficult. A strict reorganization of the hospital resources is necessary to safely resume the cardiac surgical activity.

Intraoperative support during lung transplantation

The role of intraoperative mechanical support during lung transplantation (LTx) is essential to provide a safe hemodynamic and ventilatory status during critical intraoperative events. This hemodynamic and ventilatory stability is vital to minimize the odds of suboptimal outcomes, especially considering that, due to the scarcity of donors and the fact that more and more patients with significant comorbidities are being considered for this therapy, a more aggressive approach is often needed by the transplant centers. Hence, the attenuation of any potential injury that can happen during this complex event is paramount. While a thorough assessment of the donor and optimization of postoperative care is pursued, certainly protective intraoperative management would also contribute to better outcomes. Understanding each patient’s underlying anatomy and cardiopulmonary physiology, associated with awareness of critical events during a complicated procedure like LTx, is essential for a precise indication and safe use of support. Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation (VA ECMO) have been the most common approaches used, with the latter gaining popularity more recently and we have used VA ECMO exclusively for the last decade. New technologies certainly contributed to more liberal use of VA ECMO intraoperatively, enabling a protecting and physiologic environment for the newly implanted grafts. In this setting, potential prophylactic use for lung protection during a critical period is also considered.

Lung transplantation for pulmonary hypertension

From its identification as a distinct disease entity, understanding and management of pulmonary hypertension has continuously evolved. Diagnostic and therapeutic interventions have greatly improved the prognostic implications of this devastating disease, previously rapidly and uniformly fatal to one chronically managed by multi-disciplinary teams. Improved diagnostic algorithms and active research into biochemical signatures of pulmonary hypertension (PH) have led to earlier diagnosis of PH. Medical therapy has moved from upfront use of continuous intravenous prostaglandins to administration of combinations of oral medications targeting multiple pathways underlying this disease process. In addition to improved medical therapies, recently introduced interventions such as pulmonary endarterectomy and pulmonary artery balloon angioplasty for chronic thromboembolic pulmonary hypertension (CTEPH) give patients an increasing array of treatment options. Despite these many advances, lung transplantation remains the definitive treatment for patients with disease refractory to or progressing on best medical therapy. As our understanding of medical therapy has advanced, so to have best practices for lung transplantation. Recipient selection and approach to organ transplantation techniques have continuously evolved. Mechanical circulatory support has become increasingly employed to bridge patients through lung transplantation in the immediate post transplantation recovery. In this review, we give a history of lung transplantation for PH, an overview of PH, discuss current best practices and look to the future for insights into the care of these patients.

Aortic arch surgery: what I would have done different? The Kobe/Takatsuki experience

Our current approach towards total arch replacement includes the following: (1) innominate vein mobilization, (2) no neck vessel taping, and no dissection of the vagal nerve, (3) meticulous selection of arterial cannulation site and type of arterial cannula, (4) antegrade cerebral perfusion(ACP)for neuro-protection, utilizing three balloon-tipped cannular from inside the arch, (5) whole-body hypothermia with minimal tympanic temperatures between 20 and 23 °C and minimal rectal temperatures below 30 °C, (6) distal enucleation and felt reinforcement for in zone III distal anastomosis using four branched graft, (7) early re-warming after distal anastomosis with ACP flow adjustment while monitoring brain oxygenation by near-infrared spectroscopy (NIRS) and (8) second anastomosis is proximal and last one is arch vessel reconstruction, (9) maintaining strict fluid balance below 1000 ml by the extracorporeal ultrafiltration method (ECUM) during cardiopulmonary bypass (CPB), with the expectation of more rapid pulmonary functional recovery.

Dysfunction of peripheral regulatory T cells predicts lung injury after cardiopulmonary bypass

Lung injury caused by cardiopulmonary bypass (CPB) increases the mortality after cardiac surgery. Previous studies have shown that regulatory T cells (Tregs) play a protective role during CPB, but the correlation between Tregs and CPB-induced lung injury remains unclear. Here, we conducted a prospective study about Treg cells in patient receiving CPB. Treg cells were collected from patients before the CPB operation (pre-CPB Tregs), and the effect of pre-CPB Tregs on the occurrence of CPB-induced lung injury was evaluated. Data showed that the baseline level of Treg cells in peripheral blood were lower in patients who developed lung injury after CPB, compared to those who did not develop lung injury after CPB. Function analyses revealed that pre-CPB Tregs from CPB-induced lung injury patients presented decreased ability in suppressing the proliferation and IFN-γ production of CD4 and CD8 T cell. Also, pre-surgery levels of TGF- β and IL-10 were markedly lower in lung injury patients than in non-lung injury patients. In addition, PD-1 and Tim-3 expression on pre-CPB Tregs were significantly lower in CPB-induced lung injury patients than the CPB patients without lung injury. Above all, we found impaired peripheral Treg responses in CPB-induced lung injury patients, indicating a potential role of Treg cells in the early diagnosis of CPB-induced lung injury.

Vaping Contributing to Postoperative Acute Respiratory Distress Syndrome

We report the case of an 18-year-old male patient with a history of bicuspid aortic valve with severe aortic insufficiency who had undergone a Ross procedure 1 year prior but subsequently developed stenosis of the pulmonary homograft necessitating conduit replacement. His postoperative course was complicated by acute respiratory distress syndrome. Bronchoscopy revealed significant mucus plugging without identification of contributing pathogen. Further evaluation revealed a history of electronic cigarette use not identified preoperatively and thought to be largely contributory to his postoperative complications. This case highlights the importance of screening preoperatively for electronic cigarette use and counseling on cessation before surgical procedures.

Lung Injury After Neonatal Congenital Cardiac Surgery Is Mild and Modifiable by Corticosteroids

OBJECTIVES

The present study was performed to determine whether lung injury manifests as lung edema in neonates after congenital cardiac surgery and whether a stress-dose corticosteroid (SDC) regimen attenuates postoperative lung injury in neonates after congenital cardiac surgery.

DESIGN

A supplementary report of a randomized, double-blinded, placebo-controlled clinical trial.

SETTING

A pediatric tertiary university hospital.

PARTICIPANTS

Forty neonates (age ≤28 days) undergoing congenital cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

After anesthesia induction, patients were assigned randomly to receive intravenously either 2 mg/kg methylprednisolone or placebo b, which was followed by hydrocortisone or placebo bolus six hours after weaning from CPB for five days as follows: 0.2 mg/kg/h for 48 hours, 0.1 mg/kg/h for the next 48 hours, and 0.05 mg/kg/h for the following 24 hours.

MEASUREMENTS AND MAIN RESULTS

The chest radiography lung edema score was lower in the SDC than in the placebo group on the first postoperative day (POD one) (p = 0.03) and on PODs two and three (p = 0.03). Furthermore, a modest increase in the edema score of 0.9 was noted in the placebo group, whereas the edema score remained at the preoperative level in the SDC group. Postoperative dynamic respiratory system compliance was higher in the SDC group until POD three (p < 0.01). However, postoperative oxygenation; length of mechanical ventilation; and tracheal aspirate biomarkers of inflammation and oxidative stress, namely interleukin-6, interleukin-8, resistin, and 8-isoprostane, showed no differences between the groups.

CONCLUSIONS

The SDC regimen reduced the development of mild and likely clinically insignificant radiographic lung edema and improved postoperative dynamic respiratory system compliance without adverse events, but it failed to improve postoperative oxygenation and length of mechanical ventilation.

Impact of nosocomial infections on patient mortality following cardiac surgery

STUDY OBJECTIVE

To determine the rate of nosocomial infection among patients undergoing cardiac surgery and to identify risk factors and the impact of these infections on patient mortality.

DESIGN

Prospective observational study.

SETTING

Intensive Care Unit (ICU).

PATIENTS

1097 adult patients who underwent cardiac surgery at Hospital Clínico Universitario de Valladolid between January 2011 and January 2016.

INTERVENTIONS

None.

MEASUREMENTS

Preoperative, intraoperative and postoperative medical, surgical and anaesthetic variables.

MAIN RESULTS

A total of 111 patients (10.1%) acquired a nosocomial infection in the postoperative period. Pneumonia was the most frequent (4.2%) nosocomial infection. Three independent risk factors for the development of a nosocomial infection were identified: cardiopulmonary bypass time, kidney failure and emergency surgery. The stay in the ICU was significantly higher in patients who developed a nosocomial infection (16.6 ± 38.8 vs. 4.4 ± 17.8, P < 0.001). The mortality rate of patients who acquired a nosocomial infection was significantly greater (18%) than that of patients who did not acquire a nosocomial infection (5%) (P < 0.001). The 90-day survival was greater in the group of patients without nosocomial infection (log rank 27.55, P < 0.001). The dynamic modelling of 90-day mortality revealed that in the first week, cardiopulmonary bypass time (HR = 1.00, 95% CI 1.00-1.02, P < 0.001) and emergency surgery (HR = 0.12, 95% CI 0.04-0.37, P < 0.001) were the most important risk factors for mortality, while after the first week, nosocomial infection (HR = 6.23, 95% CI 2.49-15.63, P < 0.001) was the main risk factor, followed by cardiopulmonary bypass time (HR = 1.01, 95% CI 1.00-1.01, P = 0.001) and EuroSCORE (HR = 1.03, 95% CI 1.00-1.06, P = 0.008).

CONCLUSIONS

Nosocomial infections after cardiac surgery constitute the main independent risk factor for mortality after the first week of surgery. These data suggest that its prevention following cardiac surgery must be prioritised to improve patient outcomes.

Patient and haemodynamic factors affecting intraoperative graft flow during coronary artery bypass grafting: an observational pilot study

Transit-time flow measurement (TTFM) is frequently used to evaluate intraoperative quality control during coronary artery bypass grafting (CABG) and has the ability to assess graft failure intraoperatively. However, perioperative factors affecting TTFM during CABG remain poorly understood. Patients who underwent CABG at a single institution between July 2016 and May 2018 were prospectively evaluated. TTFM and blood viscosity were measured haemodynamically, while mean flow (mL/min), pulsatility index, and diastolic filling were recorded. Arterial blood gas was analysed immediately after left internal mammary artery to left descending artery anastomosis and before sternal closure. Factors associated with TTFM were assessed using multiple linear regression analysis. We evaluated 57 of the 62 patients who underwent CABG during the study period, including 49 who underwent off-pump and 8 who underwent on-pump surgeries. Blood viscosity was not significantly associated with TTFM (p > 0.05). However, TTFM was significantly associated with body mass index, systolic blood pressure, and cardiac index (p < 0.05 each). In conclusion, maintaining the SBP in the perioperative period and maintaining the CI with inotropic support or fluid resuscitation can be important in improving blood flow of graft vessels after surgery.

Impact of vital capacity on outcome after total arch replacement

OBJECTIVES

Although chronic obstructive pulmonary disease has been recognized as a significant risk factor for open-heart surgery, the relationship between vital capacity and postoperative outcomes remains unclear. Our objective was to analyze the effect of vital capacity on outcomes after total arch replacement.

METHODS

Between January 2003 and December 2018, 228 patients undergoing total arch replacement who were elective cases with preoperative spirometry records were retrospectively reviewed. Patients were divided into two groups, based on whether their preoperative vital capacity was less than or greater than 2.5 L. We compared perioperative data and long-term outcome after adjusting their backgrounds by propensity score matching analysis.

RESULTS

The lower vital capacity group had more tracheostomy patients (5.1% vs 0.0%; p = 0.045). The actuarial survival rate was 58.0% in the lower vital capacity group and 86.3% in the higher vital capacity group at 8 years. Log-rank analysis revealed a significant difference between the two groups (p = 0.011). In the multivariate Cox proportional hazard model, vital capacity < 2.5 L (p = 0.024) and estimated glomerular filtration rate < 30mL/minute/1.73 m² (p = 0.012) showed a significant association with a higher risk of long-term mortality.

CONCLUSIONS

Vital capacity should be considered an important risk factor for postoperative respiratory complications and long-term mortality in patients undergoing total arch replacement.

Ma Xing Shi Gan Decoction Attenuates PM2.5 Induced Lung Injury via Inhibiting HMGB1/TLR4/NFκB Signal Pathway in Rat

Ma Xing Shi Gan Decoction (MXD), a classical traditional Chinese medicine prescription, is widely used for the treatment of upper respiratory tract infection. However, the effect of MXD against particulate matters with diameter of less than 2.5 μm (PM2.5) induced lung injury remains to be elucidated. In this study, rats were stimulated with PM2.5 to induce lung injury. MXD was given orally once daily for five days. Lung tissues were harvested to assess pathological changes and edema. Myeloperoxidase (MPO) activity and malonaldehyde (MDA) content in lung were determined to evaluate the degree of injury. To assess the barrier disruption, the bronchoalveolar lavage fluid (BALF) was collected to determine the total protein content and count the number of neutrophils and macrophages. For evaluating the activation of macrophage in lung tissue, CD68 was detected using immunohistochemistry (IHC). The levels of inflammatory factors including tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-6 (IL-6) in BALF and serum were measured. In vitro, a PM2.5-activated RAW 264.7 macrophages inflammatory model was introduced. To evaluate the protective effect of MXD-medicated serum, the cell viability and the release of inflammatory factors were measured. The effects of MXD on the High mobility group box-1/Toll-like receptor 4/Nuclear factor-kappa B (HMGB1/TLR4/NFκB) pathway in lung tissue and RAW 264.7 cells were assessed by Western blot. For further confirming the protective effect of MXD was mediated by inhibiting the HMGB1/TLR4/NFκB pathway, RAW 264.7 cells were incubated with MXD-medicated serum alone or MXD-medicated serum plus recombinant HMGB1 (rHMGB1). MXD significantly ameliorated the lung injury in rats, as evidenced by decreases in the pathological score, lung edema, MPO activity, MDA content, CD68 positive macrophages number, disruption of alveolar capillary barrier and the levels of inflammatory factors. In vitro, MXD-medicated serum increased cell viability and inhibited the release of inflammatory cytokines. Furthermore, MXD treatment was found to inhibit HMGB1/TLR4/NFκB signal pathway both in vivo and in vitro. Moreover, the protection of MXD could be reversed by rHMGB1 in RAW 264.7. Taken together, these results suggest MXD protects rats from PM2.5 induced acute lung injury, possibly through the modulation of HMGB1/TLR4/NFκB pathway and inflammatory responses.

Mitochondrial transplantation enhances murine lung viability and recovery after ischemia-reperfusion injury

The most common cause of acute lung injury is ischemia-reperfusion injury (IRI), during which mitochondrial damage occurs. We have previously demonstrated that mitochondrial transplantation is an efficacious therapy to replace or augment mitochondria damaged by IRI, allowing for enhanced muscle viability and function in cardiac tissue. Here, we investigate the efficacy of mitochondrial transplantation in a murine lung IRI model using male C57BL/6J mice. Transient ischemia was induced by applying a microvascular clamp on the left hilum for 2 h. Upon reperfusion mice received either vehicle or vehicle-containing mitochondria either by vascular delivery (Mito V) through the pulmonary artery or by aerosol delivery (Mito Neb) via the trachea (nebulization). Sham control mice underwent thoracotomy without hilar clamping and were ventilated for 2 h before returning to the cage. After 24 h recovery, lung mechanics were assessed and lungs were collected for analysis. Our results demonstrated that at 24 h of reperfusion, dynamic compliance and inspiratory capacity were significantly increased and resistance, tissue damping, elastance, and peak inspiratory pressure (Mito V only) were significantly decreased (P < 0.05) in Mito groups as compared with their respective vehicle groups. Neutrophil infiltration, interstitial edema, and apoptosis were significantly decreased (P < 0.05) in Mito groups as compared with vehicles. No significant differences in cytokines and chemokines between groups were shown. All lung mechanics results in Mito groups except peak inspiratory pressure in Mito Neb showed no significant differences (P > 0.05) as compared with Sham. These results conclude that mitochondrial transplantation by vascular delivery or nebulization improves lung mechanics and decreases lung tissue injury.

Impact of Cardiopulmonary Bypass and Aorta Cross Clamp Time on the Length of Mechanical Ventilation after Cardiac Surgery among Children: A Saudi Arabian Experience

Aim Several factors determine the perioperative outcome besides the nature of the congenital heart defect. Prolonged mechanical ventilation (PMV) is a major factor that determines mortality, length of stay (LOS), residual disability, and other functional outcomes. We aim to determine the clinical variables predicting PMV and LOS in hospital, and specifically the impact from the duration of cardiopulmonary bypass (CPB) and aortic cross-clamp (ACC). Method We conducted a retrospective review of the medical records of 413 children consecutively admitted to the Pediatric Cardiac Intensive Care Unit (PCICU) in one year at a single center. We collected demographic information (e.g., age, gender, and weight), perioperative variables, clinical outcomes, length of mechanical ventilation, high-frequency ventilator use, and mortality. We used logistic regression to analyze the data. PMV was defined as mechanical ventilation for longer than seven days. Results A total of 410 records were included in our study. We found no statistically significant association between CPB time and mechanical ventilation days. Forty-seven children had PMV, 362 did not have PMV. We found no statistically significant association between CPB time and mechanical ventilation days after adjusting for covariates. Reanalyzing the data with PMV defined as longer than four days produced the same results. Using a regression model to assess the variables via the least absolute shrinkage and selection operator for feature selection, we found no statistically significant association between ACC time and mechanical ventilation days after adjusting for covariates. Conclusion According to our results, CPB and ACC time are not associated with PMV or prolonged hospital LOS.

Extracorporeal life support and systemic inflammation

Extracorporeal life support (ECLS) encompasses a wide range of extracorporeal modalities that offer short- and intermediate-term mechanical support to the failing heart or lung. Apart from the daily use of cardiopulmonary bypass (CPB) in the operating room, there has been a resurgence of interest and utilization of veno-arterial and veno-venous extracorporeal membrane oxygenation (VA- and VV-ECMO, respectively) and extracorporeal carbon dioxide removal (ECCO₂R) in recent years. This might be attributed to the advancement in technology, nonetheless the morbidity and mortality associated with the clinical application of this technology is still significant. The initiation of ECLS triggers a systemic inflammatory response, which involves the activation of the coagulation cascade, complement systems, endothelial cells, leukocytes, and platelets, thus potentially contributing to morbidity and mortality. This is due to the release of cytokines and other biomarkers of inflammation, which have been associated with multiorgan dysfunction. On the other hand, ECLS can be utilized as a therapy to halt the inflammatory response associated with critical illness and ICU therapeutic intervention, such as facilitating ultra-protective mechanical ventilation. In addition to addressing the impact on outcome of the relationship between inflammation and ECLS, two different but complementary pathophysiological perspectives will be developed in this review: ECLS as the cause of inflammation and ECLS as the treatment of inflammation. This framework may be useful in guiding the development of novel therapeutic strategies to improve the outcome of critical illness.

Risk factor analysis of postoperative acute respiratory distress syndrome after type A aortic dissection repair surgery

To investigate the incidence, outcomes, and risk factors of postoperative acute respiratory distress syndrome (ARDS) in patients undergoing surgical repair for acute type A aortic dissection.This retrospective study involved 270 patients who underwent surgical repair for acute type A aortic dissection between January 2009 and December 2015. Data on clinical characteristics and outcomes were collected. Patients who immediately died after surgery and with preoperative myocardial dysfunction were excluded. The included patients were divided into the ARDS (ARDS patients who met the Berlin definition) and non-ARDS groups. Primary outcome was postoperative ARDS, according to the 2012 Berlin definition for ARDS and was reviewed by 2 qualified physicians with expertise in critical care and cardiac surgery. Outcomes of interest were the incidence and severity of risk factors for ARDS in this population, and perioperative outcomes and survival rates were compared with patients with or without ARDS.A total of 233 adult patients were enrolled into this study; of these, 37 patients (15.9%) had ARDS. Three, 20, and 14 patients had mild, moderate, and severe ARDS, respectively, according to the Berlin definition, with no significant difference in age, sex, and underlying disease. The ARDS group had lower mean oxygenation index (OI) than the non-ARDS group in the first 3 days post-surgery and demonstrated an improvement in lung function after the fourth day. Postoperative complication risks were higher in the ARDS group than in the non-ARDS group. However, no significant difference was observed in in-hospital mortality between the 2 groups (10.8% vs 5.6%, P = .268). Additionally, there was also no significant difference in the 3-year mortality rate between the 2 groups (P of log-rank test = .274). Postoperative hemoglobin level (odds ratio [OR]: 0.78; 95% confidence interval [CI]: 0.62-0.99) and perioperative blood transfusion volume (OR: 1.07; 95% CI: 1.03-1.12) were associated with ARDS risk.Postoperative ARDS after type A aortic dissection repair surgery was associated with risks of postoperative complications but not with risk of in-hospital mortality or 3-year mortality. A higher perioperative blood transfusion volume and a lower postoperative hemoglobin level may be risk factors for ARDS.

Protective effect of oxytocin on LPS-induced acute lung injury in mice

Oxytocin (OT), a neurohypophyseal hormone synthesized in the paraventricular and supraoptic nuclei of the hypothalamus, has been reported to have an anti- inflammatory effect. However, its role in acute lung injury (ALI) has never been investigated. The aim of this study was to explore the therapeutic effects and potential mechanism action of OT on lipopolysaccharide (LPS)-induced ALI. Mice were treated with OT 30 min before the intraperitoneal injection of LPS. After 2 h, the effects of OT on lung histopathological changes, lung wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, levels of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), and expression of inflammation proteins were detected. The results showed that OT significantly reduced LPS-induced pathological injury, W/D ratio, MPO activity, and the levels of interleukin (IL)-1β, IL-18 and IL-6. Further, OT also inhibited LPS-induced Toll-like receptor 4 expression and NLR family pyrin domain containing 3 inflammasome activation. OT receptor antagonist (L-368,899) was given 90 min before injecting OT to further demonstrate the role of OT in LPS-induced ALI. The results showed OT could not alleviate the aforementioned inflammatory reactions after administering L-368,899. In conclusion, the present results indicated that OT could reduce inflammatory responses of LPS-induced ALI.

Isoalantolactone suppresses LPS-induced inflammation by inhibiting TRAF6 ubiquitination and alleviates acute lung injury

Isoalantolactone (IAL) is a sesquiterpene lactone extracted from roots of Inula helenium L and has shown anti-inflammatory effects. In this study we investigated the therapeutic effects of IAL on acute lung injury (ALI) and elucidated the mechanisms underlying its anti-inflammation potential in vitro and in vivo. Treatment with lipopolysaccharide (LPS, 100 ng/mL) drastically stimulated production of inflammatory mediators such as NO, TNF-α, IL-1β, and IL-6 in mouse bone marrow-derived macrophages (BMDMs), which was dose-dependently suppressed by pretreatment with IAL (2.5, 5, 10, 20 μM). We further revealed that IAL suppressed LPS-induced NF-κB, ERK, and Akt activation. Moreover, the downregulation of non-degradable K63-linked polyubiquitination of TRAF6, an upstream transcription factor of NF-κB, contributed to the anti-inflammatory effects of IAL. ALI was induced in mice by intratracheal injection of LPS (5 mg/kg). Administration of IAL (20 mg/kg, i.p.) significantly suppressed pulmonary pathological changes, neutrophil infiltration, pulmonary permeability, and pro-inflammatory cytokine expression. Our results demonstrate that IAL is a potential therapeutic reagent against inflammation and ALI.

Sialic Acid-Functionalized PEG-PLGA Microspheres Loading Mitochondrial-Targeting-Modified Curcumin for Acute Lung Injury Therapy

Acute lung injury (ALI) is a serious illness without resultful therapeutic methods commonly. Recent studies indicate the importance of oxidative stress in the occurrence and development of ALI, and mitochondria targeted antioxidant has become a difficult and hot topic in the research of ALI. Therefore, a sialic acid (SA)-modified lung-targeted microsphere (MS) for ALI therapy are developed, with triphenylphosphonium cation (TPP)-modified curcumin (Cur-TPP) loaded, which could specifically target the mitochondria, increasing the effect of antioxidant. The results manifest that with the increase of microsphere, lung distribution of microsphere is also increased in murine mice, and after SA modification, the microsphere exhibits the ideal lung-targeted characteristic in ALI model mice, due to SA efficiently targeting to E-selectin expressed on inflammatory tissues. Further investigations indicate that SA/Cur-TPP/MS has better antioxidative capacity, decreases intracellular ROS generation, and increases mitochondrial membrane potential, contributing to a lower apoptosis rate in human umbilical vein endothelial cells (HUVECs) compared to H₂O₂ group. In vivo efficacy of SA/Cur-TPP/MS demonstrates that the inflammation has been alleviated markedly and the oxidative stress is ameliorated efficiently. Significant histological improvements by SA/Cur-TPP/MS are further proved via HE stains. In conclusion, SA/Cur-TPP/MS might act as a promising drug formulation for ALI therapy.

Protective and Therapeutic Effects of Engeletin on LPS-Induced Acute Lung Injury

Acute lung injury (ALI) is a serious disease with morbidity and mortality in patients. Engeletin (dihydrokaempferol 3-rhamnoside) is a flavanonol glycoside. It can be found in the skin of white grapes and white wine and is widely distributed in southeast Asia. In our study, we evaluated the protective and therapeutic effects of engeletin on lipopolysaccharide (LPS)-induced ALI in animal model. We determined the level of peroxisome proliferator-activated receptor-γ (PPAR-γ), nuclear factor kappaB (NF-κB), and IκBα by western blotting. The myeloperoxidase (MPO) activity and lung wet/dry (W/D) ratio in lung tissues were also detected. Histopathological changes and the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β were determined by H&E staining and ELISA. The MPO activity and lung W/D ratio induced by LPS were attenuated by engeletin. The numbers of inflammatory cells and the levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were ameliorated by engeletin. Furthermore, the results also showed that engeletin significantly suppressed LPS-induced NF-κB activation. The expression of PPAR-γ was upregulated by treatment of engeletin. In conclusion, we found that engeletin had protective and therapeutic effects against LPS-induced ALI by activating PPAR-γ. Engeletin is a potentially effective agent for the treatment of lung injury.

Lung recruitment improves right ventricular performance after cardiopulmonary bypass: A randomised controlled trial

BACKGROUND

Atelectasis after cardiopulmonary bypass (CPB) can affect right ventricular (RV) performance by increasing its outflow impedance.

OBJECTIVE

The aim of this study was to determine whether a lung recruitment manoeuvre improves RV function by re-aerating the lung after CPB.

DESIGN

Randomised controlled study.

SETTING

Single-institution study, community hospital, Córdoba, Argentina.

PATIENTS

Forty anaesthetised patients with New York Heart Association class I or II, preoperative left ventricular ejection fraction at least 50% and Euroscore 6 or less scheduled for cardiac surgery with CPB.

INTERVENTIONS

Patients were assigned to receive either standard ventilation with 6 cmH2O of positive end-expiratory pressure (PEEP; group C, n = 20) or standard ventilation with a recruitment manoeuvre and 10 cmH2O of PEEP after surgery (group RM, n = 20). RV function, left ventricular cardiac index (CI) and lung aeration were assessed by transoesophageal echocardiography (TOE) before, at the end of surgery and 30 min after surgery.

MAIN OUTCOME MEASURES

RV function parameters and atelectasis assessed by TOE.

RESULTS

Haemodynamic data and atelectasis were similar between groups before surgery. At the end of surgery, CI had decreased from 2.9 ± 1.1 to 2.6 ± 0.9 l min m in group C (P = 0.24) and from 2.8 ± 1.0 to 2.6 ± 0.8 l min m in group RM (P = 0.32). TOE-derived RV function parameters confirmed a mild decrease in RV performance in 95% of patients, without significant differences between groups (multivariate Hotelling t-test P = 0.16). Atelectasis was present in 18 patients in group C and 19 patients in group RM (P = 0.88). After surgery, CI decreased further from 2.6 to 2.4 l min m in group C (P = 0.17) but increased from 2.6 to 3.7 l min m in group RM (P < 0.001). TOE-derived RV function parameters improved only in group RM (Hotelling t-test P < 0.001). Atelectasis was present in 100% of patients in group C but only in 10% of those in group RM (P < 0.001).

CONCLUSION

Atelectasis after CPB impairs RV function but this can be resolved by lung recruitment using 10 cmH2O of PEEP.

TRIAL REGISTRATION

Protocol started on October 2014.

Saikosaponin a Ameliorates LPS-Induced Acute Lung Injury in Mice

The purpose of this study was to investigate the protective effects of Saikosaponin a (SSa), a triterpene saponin derived from Radix bupleuri, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) using a murine model. The mice were given SSa 1 h after intranasal instillation of LPS. Then, lung histopathological examination, the wet/dry (W/D) ratio, myeloperoxidase (MPO), and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were detected in this study. The results showed that SSa reduced lung pathological injury induced by LPS. Furthermore, LPS-induced lung W/D ratio, MPO activity, and inflammatory cytokines TNF-α and IL-1β in BALF were significantly inhibited by SSa. In addition, SSa suppressed LPS-induced NF-κB activation and NLRP3 inflammasome expression. In conclusion, we found that SSa played a critical anti-inflammatory effect through inhibition of NF-κB and NLRP3 signaling pathways and protected against LPS-induced ALI.

The relationship between low survival and acute increase of tumor necrosis factor α expression in the lung in a rat model of asphyxial cardiac arrest

Cardiac arrest (CA) is sudden loss of heart function and abrupt stop in effective blood flow to the body. The patients who initially achieve return of spontaneous circulation (RoSC) after CA have low survival rate. It has been known that multiorgan dysfunctions after RoSC are associated with high morbidity and mortality. Most previous studies have focused on the heart and brain in RoSC after CA. Therefore, the aim of this research was to perform serological, physiological, and histopathology study in the lung and to determine whether or how pulmonary dysfunction is associated with low survival rate after CA. Experimental animals were divided into sham-operated group (n=14 at each point in time), which was not subjected to CA operation, and CA-operated group (n=14 at each point in time), which was subjected to CA. The rats in each group were sacrificed at 6 hours, 12 hours, 24 hours, and 2 days, respectively, after RoSC. Then, pathological changes of the lungs were analyzed by hematoxylin and eosin staining, Western blot and immunohistochemistry for tumor necrosis factor α (TNF-α). The survival rate after CA was decreased with time past. We found that histopathological score and TNF-α immunoreactivity were significantly increased in the lung after CA. These results indicate that inflammation triggered by ischemia-reperfusion damage after CA leads to pulmonary injury/dysfunctions and contributes to low survival rate. In addition, the finding of increase in TNF-α via inflammation in the lung after CA would be able to utilize therapeutic or diagnostic measures in the future.