Over-expression of programmed death-ligand 1 and programmed death-1 on antigen-presenting cells as a predictor of organ dysfunction and mortality during early sepsis: a prospective cohort study.

BACKGROUND: This study aimed to explore the changes of programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) expression on antigen-presenting cells (APCs) and evaluate their association with organ failure and mortality during early sepsis. METHODS: In total, 40 healthy controls and 198 patients with sepsis were included in this study. Peripheral blood was collected within the first 24 h after the diagnosis of sepsis. The expression of PD-L1 and PD-1 was determined on APCs, such as B cells, monocytes, and dendritic cells (DCs), by flow cytometry. Cytokines in plasma, such as interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), IL-6, IL-10, and IL-17A were determined by Luminex assay. RESULTS: PD-1 expression decreased significantly on B cells, monocytes, myeloid DCs (mDCs), and plasmacytoid DCs (pDCs) as the severity of sepsis increased. PD-1 expression was also markedly decreased in non-survivors compared with survivors. In contrast, PD-L1 expression was markedly higher on mDCs, pDCs, and monocytes in patients with sepsis than in healthy controls and in non-survivors than in survivors. The PD-L1 expression on APCs (monocytes and DCs) was weakly related to organ dysfunction and inflammation. The area under the receiver operating characteristic curve (AUC) of the PD-1 percentage of monocytes (monocyte PD-1%)+APACHE II model (0.823) and monocyte PD-1%+SOFA model (0.816) had higher prognostic value than other parameters alone. Monocyte PD-1% was an independent risk factor for 28-day mortality. CONCLUSION: The severity of sepsis was correlated with PD-L1 or PD-1 over-expression on APCs. PD-L1 in monocytes and DCs was weakly correlated with inflammation and organ dysfunction during early sepsis. The combination of SOFA or APACHE II scores with monocyte PD-1% could improve the prediction ability for mortality.

Glucocorticoid receptor expression in patients with cardiac arrest in the early period after the return of spontaneous circulation: a prospective observational single-centre study.

OBJECTIVES: Rapid changes in glucocorticoid (GC) levels and adrenal insufficiency are related to the development of post-cardiac arrest (CA) syndrome. However, GC receptor (GR) expression changes have not been studied. Hence, this study aimed to investigate the association of early changes in GR expression and prognosis and immune response in patients who experienced CA. DESIGN: Prospective observational study. SETTING: Emergency department. PARTICIPANTS: Patients (85) in the early period of return of spontaneous circulation (ROSC) after CA were admitted between October 2018 and October 2019. After a physical examination, age-matched and sex-matched healthy individuals (40) were recruited for the control group. PRIMARY AND SECONDARY OUTCOME MEASURES: GR expression and cell counts of circulatory T and B lymphocytes, natural killer cells and regulatory T (Treg) cells were assessed. Plasma total cortisol and adrenocorticotrophic hormone (ACTH) levels were also tested. RESULTS: All cell counts were lower, and plasma total cortisol levels were higher (p<0.001) in patients who experienced CA than in the healthy control group. GR expression in Treg cells and CD3+CD4+ T lymphocytes were not significantly different, but the mean fluorescence intensity and GR expression in other cells were lower in patients who experienced CA (p<0.05) than in the healthy control group. ACTH levels were not different. There were no significant differences between survivors and non-survivors. CONCLUSIONS: This study revealed that GR expression and cell counts rapidly decreased, whereas plasma total cortisol levels increased in the early period after ROSC among patients who experienced CA. Our findings provide important information about GR level and function, and immunosuppressive status in these patients. Assessing GR expression in patients who experienced CA may help screening for those who are more sensitive to GC therapy.

Effects of ulinastatin on renal perfusion evaluated by Doppler ultrasonography in a porcine model of septic shock.

The present study aimed to evaluate the effect of ulinastatin (UTI) on renal perfusion using Doppler ultrasonography in a porcine model of septic shock induced by smoking inhalation and live methicillin-resistant Staphylococcus aureus instillation. A total of 32 healthy Landrace pigs were randomly assigned into the following four groups: Sham group (SH; n=5), septic shock group (SS; n=9), septic shock treated with vancomycin (15 mg/kg) group (VAN; n=9) and septic shock treated with UTI (50,000 U/kg) + vancomycin (UTI; n=9) group. Renal perfusion was evaluated by contrast-enhanced ultrasound (CEUS) at baseline and at the end of the protocol (24 h). The spectrum of interlobar or arcuate artery was selected to calculate the corrected resistive index (cRI). Sulphur hexafluoride microbubbles were bolus injected via a venous catheter. The peak intensity (Pi) and area under curve (AUC) were calculated using a time-intensity curve. Compared with the baseline group, cRI was increased significantly at the end of the protocol, except for that in the SH group, whereas Pi decreased significantly after injury in all experimental groups but was higher in the UTI group compared with that in the SS and VAN groups (both P<0.001). Linear correlation was found between the cardiac output (CO) and Pi (R2=0.752; P<0.001). The AUC was significantly decreased after injury in the SS and VAN groups compared with the baseline group. All parameters detected by CEUS were improved in the UTI group, and significant differences were found between the UTI and SS or VAN group (all P<0.05). In conclusion, acute renal injury, which occasionally occurs during septic shock, is accompanied with a significantly lower perfusion rate in the renal microcirculation. By contrast, UTI can significantly improve renal perfusion, which can be reliably evaluated using CEUS.

A Novel Porcine Model of Septic Shock Induced by Acute Respiratory Distress Syndrome due to Methicillin-resistant Staphylococcus aureus.

BACKGROUND: Sepsis is one of the main causes of mortality in critically ill patients following progression to septic shock. To investigate the pathophysiologic changes of sepsis, we developed a novel porcine model of septic shock induced by acute respiratory distress syndrome (ARDS) due to methicillin-resistant Staphylococcus aureus(MRSA) pneumonia. METHODS: Twenty-six male Landraces (Lvyuanweiye, Beijing, China) weighing 30 ± 2 kg were divided into four groups: sham group (SH; n = 5); cotton smoke inhalation group (SM; n = 6); MRSA pneumonia group (MR; n = 6); and septic shock group with cotton smoke inhalation + MRSA pneumonia (SS; n = 9). Extensive hemodynamics, oxygen dynamics, and lung function were monitored for 24 h following the injury or until death. Tissues were collected, and histopathology evaluations were carried out. RESULTS: Blood cultures from 6 of 9 animals in the SS group were positive for MRSA. Two hours following the injury, decreased mean arterial blood pressure (60-70 mmHg) and cardiac index (<2 L.min-1.m-2) were observed in the animals in the SS group, while systemic vascular resistance index was increased. The hemodynamic characteristics of septic shock were only observed in the SS group but not significant in the other groups. The PO2/FiO2in the SM and SS groups decreased to 300 and 100, respectively. In the SS group, extravascular lung water index increased to 20 ml/kg, whereas thoracopulmonary compliance decreased to 10 ml/H2O after injury. Deterioration of pulmonary function in the SS group was more serious than the SM and MR groups. Severe lung injury in the SS group was confirmed by the histopathology evaluations. The lung injury confirmed by high-resolution thin-section computed tomography and histopathology in the SS group was more serious than those of other groups. CONCLUSIONS: In the present study, we developed a novel porcine model of septic shock induced by ARDS due to severe MRSA pneumonia with characteristic hyperdynamic and hypodynamic phases in 24 h, which mimicked the hemodynamic changing of septic shock in human.

Evaluation of serum neutrophil gelatinase-associated lipocalin in predicting acute kidney injury in critically ill patients.

Objective This investigation evaluated the real-time point-of-care testing (RT-POCT) of neutrophil gelatinase-associated lipocalin (NGAL) for detecting acute kidney injury (AKI) and prognosis of critically ill patients. Methods A total of 249 critically ill patients in the emergency department (ED), who were diagnosed with acute decompensated heart failure, sepsis or diabetic ketoacidosis were enrolled in this study. All enrolled patients were followed up for 28 days or to death and the mortalities were recorded. Serum creatinine (sCr) and NGAL were measured. Results 40.6% enrolled patients deteriorated to AKI during the observation period. The NGAL level was significantly higher in the AKI versus non-AKI group. The NGAL levels in the non-survivors group at 7-day and 28-day were significantly higher than in the survivors group. NGAL was detected as an independent risk factor of AKI, and 7-day and 28-day morality. The receiver operating characteristic curve of NGAL was calculated for diagnosing AKI; the area under the curve (AUC) was significantly higher than that of 1-day eGFR. Conclusions NGAL is an independent predictor of AKI, and 7-day and 28-day mortality in critically ill ED patients, and can be an early alert for AKI and useful for determining prognosis.

Effects of Shenfu Injection () on cerebral metabolism in a porcine model of cardiac arrest.

OBJECTIVE: To investigate the effects of Shenfu Injection (, SFI) on cerebral metabolism in a porcine model of cardiac arrest (CA). METHODS: Thirty Wuzhishan minipigs were randomly assigned to the control group (n=6), epinephrine group (EP group, n=12) and Sfigroup (n=12). After 8 min of untreated ventricular fifibrillation (VF), pigs in the EP group or Sfigroup were administered with either EP (0.02 mg/kg) or Sfi(1.0 mL/kg), respectively. After successful resuscitation, cerebrospinal fluid (CSF) levels of glucose, pyruvate, lactate, glutamate and glycerol were measured at 1, 6, 12 and 24 h after recover from spontaneous circulation (ROSC). In addition, neurologic defificit score (NDS) was calculated at 24 h after ROSC. Surviving pigs were killed at 24 h after ROSC, and the brain tissue was obtained for ultra-microstructure examination. RESULTS: Compared with the EP group, CSF glucose and pyruvate levels were higher (all P<0.01), and lactate levels were lower in the Sfigroup (P<0.01). Meanwhile, CSF glutamate and glycerol levels in the Sfigroup were lower in comparison to the EP group (all P<0.05). In addition, Sfidecreased NDS at 24 h after ROSC (P<0.01), and alleviated the histopathological damage of the brain. CONCLUSIONS: Sficould alleviate brain injury after CA, which may be associated with improving cerebral metabolism.

[Protective Effect of Shenfu Injection on Postresuscitation Lung Injury in a Porcine Model of As- physia-induced Cardiac Arrest].

Objective To observe the protective effect of Shenfu Injection ( SFI) on post-resusci- tation lung injury in a porcine model of asphyxia-induced cardiac arrest. Methods Thirty-four anaesthe- tized Wuzhi Mountain inbred miniature piglets of both sexes were subjected to asphyxia by intubation clip- ping, followed by standard cardiopulmonary resuscitation. Eighteen successfully resuscitated pigs [with recovery of return of spontaneous circulation ( ROSC) ] were divided into the SFI group and the normal saline (NS) group according to random digit table, 9 in each group. SFI at 0. 24 mg/min was intravenously pumped to piglets in the SFI group immediately from ROSC to 6 h after resuscitation, while NS at 0. 24 mg/min was intravenously pumped to piglets in the NS group immediately from ROSC to 6 h after resusci- tation. Oxygen metabolism, respiratory mechanics indices including oxygenation index (ΟI) , respiration index ( RI) , oxygen delivery ( DO2), oxygen consumption ( VO2), oxygen extraction ratio (Ο2 ER), PaCO2, lactic acid (LAC) were detected using blood gas analyzer at basic state, immediately after ROSC, 15 and 30 min, 1, 2, 4, and 6 h after ROSC. Dynamic lung compliance (Cdyn) , airway resistance (Raw), external vascular lung water index (EVLWI) , pulmonary vascular permeability index (PVPI) were monitored at each aforesaid time point. Activities of Na+-K +-ATPase and Ca² +-ATPase, contents of SOD and MDA, concentrations of TNF-α, IFN-γ, and IL-4 were determined using ELISA.IFN-γ/IL-4 ratio was calculated. Cell apoptosis was detected using TUNEL and apoptotic index (Al) calculated. Protein concentrations of Bcl-2 and Bax were detected using immunohistochemical assay, and Bax/Bcl-2 ratio calculated. Caspase-3 protein was quantitatively detected using Western blot. Results The survival rate was 88. 9% (8/9) in the SFI group and 66. 7% (6/9) in the NS group at 6 h after ROSC. The mean survival time was (5. 77 ±0. 71) h in the SFI group, longer than that in the NS group [ (4. 77 ±0. 59) h, P >0. 05]. Compared with the basic state, 01 and Cdyn obviously decreased immediately after ROSC (P <0. 05) ; RI, DO2, VΟ2, O2ER, Raw, EVLWI, PVPI, PaCO2, and LAC obviously increased immediately after ROSC (P<0. 05). All indices were recovered as time went by. Compared with the NS group, ΟI, Cdyn, DO2, VΟ2, and Ο2 ER at each time points after ROSC were significantly higher in the SFI group than in the NS group (P <0. 05, P <0. 01); RI, Raw, EVLWI, PVPI, PaCO2, and LAC were significantly lower in the SFI group than in the NS group (P <0. 05, P <0. 01 ). Compared with the NS group, activities of Na'-K '-AT- Pase and Ca² +-ATPase, contents of SOD, level of IFN-γ, IFN-γ/IL-4 ratio, concentrations of Bcl-2 in- creased more; MDA, TNF-α, IL-4 level, Al, Bax/Bcl-2 ratio, Caspase-3 protein level decreased more (P <0. 05, P <0. 01). Conclusion SFI could improve cell energy metabolism, enhance antioxidant ca- pacity of cells, reduce the release of inflammatory mediators, regulate the Thl/Th2 balance, and attenu- ate cell apoptosis of lung tissue, thereby protecting post-resuscitation lung injury.

Renal Doppler and Novel Biomarkers to Assess Acute Kidney Injury in a Swine Model of Ventricular Fibrillation Cardiac Arrest.

BACKGROUND: Majority of the research on cardiac arrest (CA) have focused on post-CA brain injury and myocardial dysfunction, the renal dysfunction and acute kidney injury (AKI) in other critical illnesses after CA have not been well described. This study was designed to assess AKI with renal Doppler and novel AKI biomarkers in a swine model of ventricular fibrillation cardiac arrest (VFCA). METHODS: Thirty healthy piglets were divided into VFCA group (n = 22) and Sham group (n = 8) in a blinded manner. Mean arterial pressure, heart rate, and cardiac output were recorded continuously. Cardiac arrest (CA) was induced by programmed electric stimulation in the VFCA group, and then cardiopulmonary resuscitation was performed. Twenty piglets returned of spontaneous circulation (ROSC) and received intensive care. Blood and urine samples were collected for AKI biomarkers testing, and Color Doppler flow imaging was performed at baseline, 6 h, 12 h, and 24 h, respectively after ROSC. At ROSC 24 h, the animals were sacrificed and a semi-quantitative evaluation of pathologic kidney injury was performed. RESULTS: In the VFCA group, corrected resistive index (cRI) increased from 0.47 ± 0.03 to 0.64 ± 0.06, and pulsatility index (PI) decreased from 0.82 ± 0.03 to 0.68 ± 0.04 after ROSC. Cystatin C (CysC) in both serum and urine samples increased at ROSC 6 h, but neutrophil gelatinase-associated lipocalin (NGAL) in serum increased to 5.34 ± 1.68 ng/ml at ROSC 6 h, and then decreased to 3.16 ± 0.69 ng/ml at ROSC 24 h while CysC increasing constantly. According to the renal histopathology, 18 of 20 animals suffered from kidney injury. The grade of renal injury was highly correlated with RI, cRI, NGAL, and CysC. Linear regression equation was established: Grade of renal injury = 0.002 × serum CysC + 6.489 × PI + 4.544 × cRI - 8.358 (r2 = 0.698, F = 18.506, P < 0.001). CONCLUSIONS: AKI is common in post-CA syndrome. Renal Doppler and novel AKI biomarkers in serum and urine are of significant importance as early predictors of post-CA AKI.

Comparison of Cerebral Metabolism between Pig Ventricular Fibrillation and Asphyxial Cardiac Arrest Models.

BACKGROUND: Morbidity and mortality after resuscitation largely depend on the recovery of brain function. Ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are the two most prevalent causes of sudden cardiac death. Up to now, most studies have focused on VFCA. However, results from the two models have been largely variable. So, it is necessary to characterize the features of postresuscitation cerebral metabolism of both models. METHODS: Forty-four Wuzhishan miniature inbred pigs were randomly divided into three groups: 18 for VFCA group, ACA group, respectively, and other 8 for sham-operated group (SHAM). VFCA was induced by programmed electric stimulation, and ACA was induced by endotracheal tube clamping. After 8 min without treatment, standard cardiopulmonary resuscitation (CPR) was initiated. Following neurological deficit scores (NDS) were evaluated at 24 h after achievement of spontaneous circulation, cerebral metabolism showed as the maximum standardized uptake value (SUVmax) was measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. Levels of serum markers of brain injury, neuron specific enolase (NSE), and S100ß were quantified with an enzyme-linked immunosorbent assay. RESULTS: Compared with VFCA group, fewer ACA animals achieved restoration of spontaneous circulation (61.1% vs. 94.4%, P < 0.01) and survived 24-h after resuscitation (38.9% vs. 77.8%, P < 0.01) with worse neurological outcome (NDS: 244.3 ± 15.3 vs. 168.8 ± 9.71, P < 0.01). The CPR duration of ACA group was longer than that of VFCA group (8.1 ± 1.2 min vs. 4.5 ± 1.1 min, P < 0.01). Cerebral energy metabolism showed as SUVmax in ACA was lower than in VFCA (P < 0.05 or P < 0.01). Higher serum biomarkers of brain damage (NSE, S100ß) were found in ACA than VFCA after resuscitation (P < 0.01). CONCLUSIONS: Compared with VFCA, ACA causes more severe cerebral metabolism injuries with less successful resuscitation and worse neurological outcome.

Neuroprotective effect of Shenfu Injection () following cardiac arrest in pig correlates with improved mitochondrial function and cerebral glucose uptake.

OBJECTIVE: To test whether Shenfu Injection (, SFI) might attenuate the impact of cerebral energy dysfunction after resuscitation in a pig model of cardiac arrest (CA). METHODS: Thirty-four Wuzhishan miniature inbred pigs were randomly divided into three groups: the SFI group (n=12), the saline group (SA group, n=12), and the sham-operated group (sham group, n=10). Following successful return of spontaneous circulation (ROSC) from 8-min untreated ventricular fibrillation, animals received a continuous infusion of either SFI (0.2 mL/min) or saline for 6 h. Cerebral performance category score was evaluated at 24 and 48 h after ROSC, followed by positron emission tomography and computed tomography scans of cerebral glucose uptake. Surviving pigs were euthanized 48 h after ROSC, and the brains were removed for detecting mitochondrial function. RESULTS: Compared with the SA group, SFI treatment produced a better neurologic outcome 48 h after ROSC (P<0.05). However, there was no significant difference of survival rate between the SA and SFI groups (83.3% vs. 81.8%, P>0.05). After ROSC, the SA group showed a decrease in the maximum standardized uptake value of different regions in the brain tissue, where SFI treatment can ameliorate these decreases (P<0.01 or P<0.05). Improved mitochondrial respiratory properties and higher mitochondrial membrane potential were also found following SFI treatment compared with the SA group at 48 h after ROSC (P<0.05 or P<0.01). CONCLUSION: SFI treatment after resuscitation has significant neuroprotective effects against disruption of cerebral energy metabolism from CA by improving glucose uptake and by normalizing mitochondrial function.

Acute kidney injury after cardiac arrest of ventricular fibrillation and asphyxiation swine model.

PURPOSES: The purposes of the study are to investigate the renal function in ventricular fibrillation (VF) and asphyxiation cardiac arrest in a swine model and to estimate the value of novel biomarkers in the acute kidney injury (AKI) after cardiac arrest. METHOD: Thirty-two healthy inbred Wu-Zhi-Shan miniature piglets were randomized into 2 groups (n = 16 per group). Cardiac arrest was induced by programmed electric stimulation and clamping the endotracheal tube in the VF group and asphyxiation group, respectively. Cardiopulmonary resuscitation was done for return of spontaneous circulation (ROSC). RESULTS: One hundred percent (16/16) ROSC was observed in the VF group, and 50% (8/16) in the asphyxiation group (P < .01). All AKI biomarkers elevated significantly after ROSC. The novel biomarkers changed much earlier than the creatinine. The concentration of novel biomarkers in the asphyxiation group was higher than the VF group. Live animals had an oliguria and developed AKI. Characteristic morphological injuries in renal tissues were observed under light microscope and transmission electron microscope and were more serious in the asphyxiation group. CONCLUSIONS: Acute kidney injury at early stage of postresuscitation is common in different causes of cardiac arrest. Asphyxiation has more severe kidney injury and gets worse prognosis.

Differences of postresuscitation myocardial dysfunction in ventricular fibrillation versus asphyxiation.

PURPOSE: This study aims to characterize postresuscitation myocardial dysfunction in 2 porcine models of cardiac arrest (CA): ventricular fibrillation cardiac arrest (VFCA) and asphyxiation cardiac arrest (ACA). METHODS: Thirty-two pigs were randomized into 2 groups. The VFCA group (n = 16) were subject to programed electrical stimulation, and the ACA group (n = 16) underwent endotracheal tube clamping to induce CA. Once induced, CA remained untreated for 8 minutes. Two minutes after initiation of cardiopulmonary resuscitation (CPR), defibrillation was attempted until return of spontaneous circulation (ROSC) was achieved or animals died. RESULTS: Return of spontaneous circulation was 100% successful in VFCA and 50% successful in ACA. Cardiopulmonary resuscitation duration in VFCA was about half as short as in ACA. The survival time of VFCA was significantly longer than that of ACA. Ventricular fibrillation cardiac arrest had better mean arterial pressure, cardiac output, and left ventricular ± dp/dt(max) after ROSC than ACA. Echocardiography revealed significantly lower left ventricular ejection fraction in ACA than in VFCA. Myocardial perfusion imaging using single-photon emission computed tomography demonstrated that myocardial injuries after ACA were more severe and widespread than after VFCA. Under a transmission electron microscope, the overall heart morphologic structure and the mitochondrial crista structure were less severely injured in the VFCA group than in the ACA group. Moreover, the percentage of apoptotic cardiomyocytes was higher in ACA than in VFCA. CONCLUSIONS: Compared with VFCA, ACA causes more severe cardiac dysfunction associated with less successful resuscitation and shorter survival time.