Showing papers by "Wanchun Tang published in 2018"

Effects of Polyethylene Glycol-20k on Postresuscitation Myocardial and Cerebral Function in a Rat Model of Cardiopulmonary Resuscitation.

Abstract: OBJECTIVES Polyethylene glycol-20k is a hybrid cell impermeant that reduces ischemia injury and improves microcirculatory flow during and following low flow states through nonenergy-dependent water transfer in the microcirculation. We investigated the effects of polyethylene glycol-20k on postresuscitation microcirculation, myocardial and cerebral function, and duration of survival in a rat model of cardiopulmonary resuscitation. DESIGN Ventricular fibrillation was induced in 20 male Sprague Dawley rats and untreated for 6 minutes. Animals were randomized into two groups (n = 10 for each group): polyethylene glycol-20k and control. Polyethylene glycol-20k (10% solution in saline, 10% estimated blood volume) and vehicle (saline) were administered at the beginning of cardiopulmonary resuscitation by continuous IV infusion. Resuscitation was attempted after 8 minutes of cardiopulmonary resuscitation. SETTING University-Affiliated Research Laboratory. SUBJECTS Sprague Dawley Rats. INTERVENTIONS Polyethylene glycol-20k. MEASUREMENTS AND MAIN RESULTS Buccal microcirculation was measured at baseline, 1, 3, and 6 hours after return of spontaneous circulation using a side-stream dark-field imaging device. Myocardial function was measured by echocardiography at baseline and every hour postresuscitation for 6 hours. The animals were then returned to their cage and observed for an additional 72 hours. Neurologic Deficit Scores were recorded at 24, 48, and 72 hours after resuscitation. Postresuscitation ejection fraction, cardiac output, and myocardial performance index were significantly improved in animals treated with polyethylene glycol-20k (p < 0.05). Perfused buccal vessel density and microcirculatory flow index values were significantly higher at all time points in the polyethylene glycol-20k group compared with the control group. Postresuscitation cerebral function and survival rate were also significantly improved in animals that received polyethylene glycol-20k. CONCLUSIONS Administration of polyethylene glycol-20k following cardiopulmonary resuscitation improves postresuscitation myocardial and cerebral function, buccal microcirculation, and survival in a rat model of cardiopulmonary resuscitation.

Is the Collapsibility Index of the Inferior Vena Cava an Accurate Predictor for the Early Detection of Intravascular Volume Change

Abstract: The ultrasonographic evaluation of inferior vena cava (IVC) parameters, particularly the collapsibility index (CI), has been widely used in the assessment of the fluid responsiveness of critically ill patients, but the results are conflicting. In this study, we aimed to investigate the early change in CI after increased intravascular volume (IVV) induced by passive leg raising (PLR). A total of 145 healthy volunteers over 18 years old were enrolled between September and December in 2015. Before and 2 min after PLR, the maximum and minimum IVC diameters (maxIVC and minIVC) were measured by color Doppler ultrasonography, and the difference in CI (ΔCI) was calculated. The heart rate (HR) and noninvasive mean arterial pressure (MAP) were also monitored. We found that there was a significant increase in the mean maxIVC and minIVC values and a reduction in CI. Nevertheless, no significant differences in HR or MAP were observed before or 2 min after PLR. The baseline CI had no relationship with individual characteristics and a multiple linear regression analysis of the ΔCI and individual characteristics showed that age, baseline CI, and BMI were independent variables for ΔCI. In conclusion, IVC-CI measured by ultrasound is useful for the detection of early IVV change induced by 2 min PLR. However, its ability to detect the increased IVV value is influenced by age, BMI, and baseline CI. Moreover, only 50.3% of the subjects had an IVC-CI reduction of more than 10%, making IVC-CI of little value for clinical applications, due to its poor sensitivity.

Analyses of changes in myocardial long non-coding RNA and mRNA profiles after severe hemorrhagic shock and resuscitation via RNA sequencing in a rat model

Abstract: Ischemia–reperfusion injury has been proven to induce organ dysfunction and death, although the mechanism is not fully understood. Long non-coding RNAs (lncRNAs) have drawn wide attention with their important roles in the gene expression of some biological processes and diseases, including myocardial ischemia–reperfusion (I/R) injury. In this paper, a total of 26 Sprague–Dawley (SD) rats were randomized into two groups: sham and ischemia–reperfusion (I/R) injury. Hemorrhagic shock was induced by removing 45% of the estimated total blood volume followed by reinfusion of shed blood. High-throughput RNA sequencing was used to analyze differentially expressed (DE) lncRNAs and messenger RNAs (mRNAs) in the heart tissue 4 h after reperfusion. Myocardial function was also evaluated. After resuscitation, the decline of myocardial function of shocked animals, expressed by cardiac output, ejection fraction, and myocardial performance index (MPI), was significant (p < 0.05). DE lncRNAs and mRNAs were identified by absolute value of fold change ≥ 2 and the false discovery rate ≤ 0.001. In rats from the I/R injury group, 851 lncRNAs and 1015 mRNAs were significantly up-regulated while 1533 lncRNAs and 1702 m RNAs were significantly down-regulated when compared to the sham group. Among the DE lncRNAs, we found 12 location-associated with some known apoptosis-related protein-coding genes which were up-regulated or down-regulated accordingly, including STAT3 and Il1r1. Real time PCR assays confirmed that the expression levels of five location-associated lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2, NONRATT006035.2 and NONRATT029969.2) and their location-associated mRNAs (STAT3 and Il1r1) in the rats from the I/R injury group were all significantly up-regulated versus the sham group. The DE lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2 and NONRATT006035.2) could be compatible with their role in myocardial protection by stimulating their co-located gene (STAT3) after hemorrhagic shock and resuscitation. The final prognosis of I/R injury might be regulated by different genes, which is regarded as a complex network.

Decreased cAMP Level and Decreased Downregulation of β1-Adrenoceptor Expression in Therapeutic Hypothermia-Resuscitated Myocardium Are Associated With Improved Post-Resuscitation Myocardial Function.

Abstract: Background Epinephrine administered during cardiopulmonary resuscitation (CPR) is associated with severe post‐resuscitation myocardial dysfunction. We previously demonstrated that therapeutic hypothermia reduced the severity of post‐resuscitation myocardial dysfunction caused by epinephrine; however, the relationship between myocardial adrenoceptor expression and myocardial protective effects by hypothermia remains unclear. Methods and Results Rats weighing between 450 and 550 g were randomized into 5 groups: (1) normothermic placebo, (2) normothermic epinephrine, (3) hypothermic placebo, (4) hypothermic epinephrine, and (5) sham (not subject to cardiac arrest and resuscitation). Ventricular fibrillation was induced and untreated for 8 minutes for all other groups. Hypothermia was initiated coincident with the start of CPR and maintained at 33±0.2°C for 4 hours. Placebo or epinephrine was administered 5 minutes after the start of CPR and 3 minutes before defibrillation. Post‐resuscitation ejection fraction was measured hourly for 4 hours then hearts were harvested. Epinephrine increased coronary perfusion pressure during CPR (27±6 mm Hg versus 21±2 mm Hg P P 1 ‐adrenoceptor expression decreased with normothermia cardiac arrest but not with hypothermia regardless of epinephrine. Conclusions Epinephrine, administered during normothermic CPR, increased the severity of post‐resuscitation myocardial dysfunction. This adverse effect was inhibited by intra‐arrest hypothermia resuscitation. Declined cAMP with more preserved β 1 ‐adrenoceptors in hypothermia‐resuscitated myocardium is associated with improved post‐resuscitated myocardial function in vivo.

Quantitative CT assessment of lung injury after successful cardiopulmonary resuscitation in a porcine cardiac arrest model of different downtimes.

Abstract: Background: Utilize quantitative computed tomography (QCT) to detect and evaluate the severity of lung injury after successful cardiopulmonary resuscitation (CPR) in a porcine cardiac arrest (CA) model with different downtimes. Methods: Twenty-one male domestic pigs weighing 38±3 kg were randomized into 3 groups: the sham group (n=5), the ventricular fibrillation (VF) 5 min (VF5) group (n=8), and the VF 10 min (VF10) group (n=8). VF was induced and untreated for 5 (VF5 group) or 10 (VF10 group) min before the commencement of manual CPR. Eight animals (8/8, 100%) in VF5 and 6 (6/8, 75%) in VF10 were successfully resuscitated. Chest QCT scans and arterial blood gas tests were performed at baseline and 6 h post-resuscitation. The QCT score, volume, and weight of ground-glass opacification (GGO), which was defined as poorly aerated regions with a CT value ranging from −500 Hounsfield units (HU) to −100 HU, and intense parenchymal opacification (IPO), which was defined as a non-aerated area with a CT value greater than −100 HU, were quantitatively measured. Results: Significantly shorter durations of CPR and fewer defibrillations were observed in the VF5 group compared with the VF10 group [duration of CPR: VF5 (6±0 minutes) versus VF10 (8.3±1.5 minutes), P<0.05; numbers of defibrillation: VF5 (1±0) versus VF10 (2.2±0.8), P<0.05]. Compared with the baseline or sham animals, declining gas exchanges (end-tidal CO 2 , PO 2 , oxygen index) were observed in both VF groups; however, there were no significant differences in gas exchanges between the VF groups. Compared with the VF5 group, the GGO QCT score, volume, and weight were significantly greater in the VF10 group (P=0.002, 0.001, and 0.002 respectively), while no significant differences were found in the IPO QCT score, volume, or weight between two the VF groups (P=0.354, 0.447, and 0.512 respectively). Conclusions: QCT analysis enables unique non-invasive assessments of different lung injuries (IPO and GGO lesions) that can clearly distinguish heterogeneous lesions and allow for early detection and quantitative monitoring of the severity of lung injury following CPR. QCT could provide a basis for clinical early ventilation strategy management after CPR.

355: the effects of repeat dosing of polyethylene glycol 20k on myocardial function

Abstract: www.ccmjournal.org Critical Care Medicine • Volume 46 • Number 1 (Supplement) Learning Objectives: Polyethylene Glycol-20K (PEG-20K) is a hybrid cell impermeant that reduces ischemia injury and improves microcirculatory flow during and following low flow states through non-energy dependent water transfer in the microcirculation. In our previous study, a single dose of PEG-20K following cardiopulmonary resuscitation (CPR) improved post-resuscitation myocardial function in a rat model of CPR. Since the half life of PEG-20K is 4 hours, we hypothesized that a second, later dose of PEG-20K may provide additional protective effects on myocardial function in a rat model of cardiopulmonary resuscitation Methods: Ventricular fibrillation was induced in 18 male SpragueDawley rats and was left untreated for 6 min. Animals were randomized into two groups (n = 9 for each group): a single dose of PEG-20K (SP group) and a second dose of PEG-20K (DP group). PEG-20K (10%, 2ml) was administered at the beginning of CPR within the SP group. PEG-20K (10%, 2ml) was administered at the beginning of CPR and 4h post-resuscitation (PR) in the DP group. Resuscitation was attempted after 8 min of CPR. Myocardial function was measured by echocardiography at baseline (BL) and every 2 hours post resuscitation for 6 hours. Results: All animals were resuscitated successfully. Post-resuscitation ejection fraction (EF) (74.65 ± 2.39%vs 74.92 ± 2.18%, 62.83 ± 2.56% vs 61.3 ± 3.25%, 59.54 ± 7.92% vs 59.03 ± 7.88% and 65.31 ± 6.18% vs 65.71 ± 5.64%, BL, PR2h, PR4h, and PR6h, respectively) and cardiac output (CO) (144.44 ± 23.76vs 133.33 ± 26.53, 94.67 ± 15.78 vs 99.29 ± 10.55, 90.00 ± 14.15 vs 89.33 ± 10.88 and 95.13 ± 21.16 vs 97.29 ± 4.19, BL, PR2h, PR4h, and PR6h, respectively) were not significantly different between the 2 groups. Conclusions: A second dose of polyethylene glycol-20K administered 4 hours post ROSC does not confer additional protective effects on myocardial function compared to a single dose administered at the onset of CPR in a rat model of cardiopulmonary resuscitation.