Protective effect of metformin on pulmonary fibrosis caused by paraquat through activating AMP-activated protein kinase pathway / 中华危重病急救医学

OBJECTIVE@#To observe whether metformin (MET) inhibits transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway by activating adenosine activated protein kinase (AMPK), so as to alleviate the pulmonary fibrosis caused by paraquat (PQ) poisoning in mice.@*METHODS@#Male C57BL/6J mice were randomly divided into the Control group, PQ poisoning model group (PQ group), MET intervention group (PQ+MET group), AMPK agonist group (PQ+AICAR group), and AMPK inhibitor group (PQ+MET+CC group), according to a random number table method. A mouse model of PQ poisoning was established by one-time peritoneal injection of 1 mL PQ solution (20 mg/kg). The Control group was injected with the same volume of normal saline. After 2 hours of modeling, the PQ+MET group was given 2 mL of 200 mg/kg MET solution by gavage, the PQ+AICAR group was given 2 mL of 200 mg/kg AICAR solution by intraperitoneal injection, the PQ+MET+CC group was given 2 mL of 200 mg/kg MET solution by gavage and then 1 mL complex C (CC) solution (20 mg/kg) was intraperitoneally injected, the Control group and PQ group were given 2 mL of normal saline by gavage. The intervention was given once a day for 21 consecutive days. The 21-day survival rate of ten mice in each group was calculated, and the lung tissues of remaining mice were collected at 21 days after modeling. The pathological changes of lung tissues were observed under light microscope after hematoxylin-eosin (HE) staining and Masson staining, and the degree of pulmonary fibrosis was evaluated by Ashcroft score. The content of hydroxyproline in lung tissue and oxidative stress indicators such as malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), phosphorylated AMPK (p-AMPK), TGF-β1 and phosphorylated Smad3 (p-Smad3) in lung tissue were detected by Western blotting.@*RESULTS@#Compared with the Control group, the 21 days survival rate was significantly reduced, lung fibrosis and Ashcroft score were significantly increased in PQ group. In addition, the content of hydroxyproline, MDA and the protein expressions of α-SMA, TGF-β1 and p-Smad3 in lung tissue were significantly increased, while the activity of SOD and the protein expressions of E-cadherin and p-AMPK were significantly decreased in PQ group. Compared with the PQ group, the 21 days survival rates of mice were significantly improved in the PQ+MET group and PQ+AICAR group (70%, 60% vs. 20%, both P < 0.05). The degree of pulmonary fibrosis and the Ashcroft score were significantly reduced (1.50±0.55, 2.00±0.63 vs. 6.67±0.52, both P < 0.05). The content of hydroxyproline and MDA in lung tissue, as well as α-SMA, TGF-β1 and p-Smad3 protein expressions were significantly reduced [hydroxyproline (mg/L): 2.03±0.11, 3.00±0.85 vs. 4.92±0.65, MDA (kU/g): 2.06±1.48, 2.10±1.80 vs. 4.06±1.33, α-SMA/GAPDH: 0.23±0.06, 0.16±0.06 vs. 1.00±0.09, TGF-β1/GAPDH: 0.28±0.03, 0.53±0.05 vs. 0.92±0.06 p-Smad3/GAPDH: 0.52±0.04, 0.69±0.06 vs. 1.11±0.10, all P < 0.05], SOD activity and the protein expressions of E-cadherin and p-AMPK were significantly increased [SOD (μmol/g): 39.76±1.35, 33.03±1.28 vs. 20.08±1.79, E-cadherin/GAPDH: 0.91±0.08, 0.72±0.08 vs. 0.26±0.04, p-AMPK/GAPDH: 0.62±0.04, 0.60±0.01 vs. 0.20±0.04, all P < 0.05]. However, these protective effects of MET were inhibited by the addition of AMPK inhibitor CC solution.@*CONCLUSIONS@#MET can effectively alleviate the degree of pulmonary fibrosis in mice poisoned with PQ, and its mechanism may be related to the activation of AMPK and inhibition of TGF-β1/Smad3 signaling pathway, which can be inhibited by AMPK inhibitor CC.

Research progress of S-nitrosoglutathione reductase inhibitors in the regulation of cerebral injury after cardiac arrest-cardiopulmonary resuscitation / 中华危重病急救医学

The cerebral ischemia-reperfusion injury (CIRI) after the cardiac arrest (CA)-cardiopulmonary resuscitation (CPR) was a complex pathophysiology process. Nitric oxide (NO) is a small molecule that mediates cell signal transduction in vivo and plays an important role in the regulation of brain function during ischemia/reperfusion (I/R). S-nitrosoglutathione reductase (GSNOR) inhibitor can regulate the synthesis and release of NO in vivo and has a protective effect on CIRI. Therefore, early administration of GSNOR to CA-CPR patients could be the main treatment method to improve the prognosis of those patients. A large number of studies have been done to improve the prognosis of CA-CPR in recent years. In order to provide reference for further research on the treatment and brain protection of CIRI after CA-CPR, the article reviewed the main mechanisms of brain injury after CA-CPR, the protective effect and mechanism of NO on cerebral I/R injury, the production and regulation of NO, in vivo, and the protective effect of GSNOR inhibitors on CIRI, especially the research progress of GSNOR inhibitors.

Advances in the study of optimum chest compression point for adult cardiopulmonary resuscitation / 中华危重病急救医学

Chest compressions are a key component of cardiopulmonary resuscitation (CPR). The determination of the optimal compression point (OCP) in adult CPR is an indispensable critical factor for high quality chest compressions (CCs). At present, the OCP for adult CPR is still controversial, which still needs further research and discussion. To provide theoretical reference for determining the OCP, this paper reviews the research progress of the OCP of adult CPR from the development process of compression point and hemodynamic mechanism, so as to improve the quality of CCs and the outcome of cardiac arrest (CA) patients.

Research progress on the relationship between diquat poisoning and nuclear factor E2-related factor 2 signaling pathway / 中华危重病急救医学

Since the production and use of paraquat was banned in China in 2016, the use of diquat (DQ) has been increasing and the clinical cases of DQ poisoning have also shown an increasing trend every year. The treatment of DQ poisoning is a worldwide medical problem, and there is no specific antidote. Studies have found that oxidative stress, lipid peroxidation, neurotoxicity, reproductive and developmental toxicity play an important role in DQ poisoning. Nuclear factor E2-related factor 2 (Nrf2) can inhibit oxidative stress, lipid peroxidation and inflammation by regulating the protein expression of upstream and downstream signaling molecules. Therefore, the role of Nrf2 signaling pathway in the poisoning and treatment of DQ has become a hot spot of attention for emergency critical care researchers in recent years. This paper reviews the relationship between Nrf2 signal pathway and DQ poisoning, in order to provide a theoretical basis for improving the treatment strategy for DQ poisoning.

Progress in the study of pulmonary fibrosis signaling pathways caused by paraquat poisoning / 中华危重病急救医学

Paraquat is a quaternary ammonium herbicide, which can be distributed in lung, liver, kidney, heart, brain and other organs through blood circulation, leading to multiple organ failure, especially lung injury. Due to the lack of effective treatment methods and specific antidotes, the prognosis of most patients with paraquat poisoning is very poor. The treatment of paraquat poisoning was a big problem for emergency doctors. Previous studies have found that pulmonary fibrosis caused by paraquat poisoning is closely related to a variety of pathological processes, such as oxidative stress, inflammatory reaction, mitochondrial damage, imbalance of extracellular matrixproduction (ECM) and degradation, which involve the activation or inhibition of various signaling pathways. In recent years, many researchers focused on clarifying the mechanism of paraquat induced pulmonary fibrosis, and some signaling pathways related to paraquat poisoning leading to pulmonary fibrosis have been found. A large number of studies have found that adenosine monophosphate activated protein kinase (AMPK) related signaling pathway, transforming growth factor-β/Smad (TGF-β/Smad)signaling pathway, mitogen-activated protein kinase (MAPK) related signaling pathway, Ras homolog gene/Rho associated kinases (Ras/ROCK) and Wnt/β-catenin signal pathways are closely related to paraquat induced pulmonary fibrosis. In this paper, we reviewed signaling pathways related to paraquat induced pulmonary fibrosis, in order to provide more ideas for the clinical treatment of paraquat induced pulmonary fibrosis.

Advances in the application of epinephrine in adult cardiopulmonary resuscitation / 中国中西医结合急救杂志

Objective Cardiac arrest is a major problem that cannot be ignored both at home and abroad. So far, cardiac arrest survival rates are very low. Epinephrine has been used as a major cardiopulmonary resuscitation (CPR) drug for more than half a century, but there are still many controversies about it, such as increasing the risk of malignant arrhythmia, reducing the long-term survival rate and good prognosis rate of neurological function. The history, mechanism and research progress of epinephrine in CPR is reviewed to provide a more comprehensive understanding of epinephrine and new ideas about epinephrine reasonable usage.

Application effects of mechanical chest compression combined with manual chest compression in cardiopulmonary resuscitation for patients with in-hospital cardiac arrest: a Meta-analysis / 中国中西医结合急救杂志

Objective To systematically evaluate the effects of mechanical chest compression (CC) combined with manual CC and single-manual CC on the outcome indexes of cardiopulmonary resuscitation (CPR) for patients with in-hospital cardiac arrest (IHCA). Methods The relevant publicly published literatures about the effects of mechanical CC combined with manual CC and single-manual CC on the outcome of CPR were searched by using the following Chinese keywords for retrieval: "cardiac arrest, asystole, sudden death, artificial recovery, artificial press, artificial CC, unarmed CPR, unarmed resuscitation, unarmed compressions, unarmed chest compressions, unarmed, artificial, resuscitation instrument, resuscitation machine, resuscitator, CPR, LUCAS, Autopulse, Thumper, MSCPR-1A"in databases such as China Biomedical Literature (CBM), VIP, Wanfang, and China National Knowledge Internet (CNKI) from their dates of foundation to March 11, 2019, and using the following key words in English "heart arrest, cardiac arrest, cardiopulmonary arrest, Cardiopulmonary Resuscitation, Resuscitation, Cardio-Pulmonary Resuscitation, CPR, compression, mechanical, automatic, automated, load distributing band, LBD, Autopulse, LUCAS" to retrieve all the published articles especially concerning the topics on the application effects of mechanical combined with manual CC for IHCA patients' CPR in the America National Library database (PubMed), Excerpta Medica (EMbase), Web of Science, and Cochrane Library from the establishment of the databases to March 11, 2019. The indexes of outcomes included return of spontaneous circulation (ROSC) rate, survival rate after hospital discharge and incidence of complications. The literatures were extracted independently by two reviewers, the qualities of the included randomized controlled trials (RCTs) were evaluated according to the Cochrane bias risk assessment tool, and the qualities of the included observational studies were evaluated according to the literature quality assessment form (NOS). Meta analysis was performed by using RevMan 5.3 software, and publication bias was assessed by using funnel plot. Results Twenty-one studies were enrolled, including 11 RCT articles and 10 observational studies; there were 2 005 participants. The results of this Meta-analysis showed that compared with manual CC, the ROSC rate and after discharge survival rate of IHCA patients were obviously higher in combined CC group [ROSC: odds ratio (OR) = 2.50, 95% confidence interval (95%CI) = 2.03-3.09, P < 0.000 01; discharge survival rate: OR = 2.71, 95%CI = 1.91-3.85, P < 0.000 01]; the incidence of complications of combined CC was lower than that in single manual CC (OR = 0.30, 95%CI = 0.13-0.68, P = 0.004). The funnel plots indicated that there was no apparent bias in the ROSC; because the enrolled studies were relatively few, it was difficult to evaluate the symmetrical characteristics of the funnel plots for discharge survival rate and the complication rate. Conclusions For IHCA patients, combined CC can improve ROSC, discharge survival rate, and reduce the occurrence of complications. It is suggested that during the actual rescue of IHCA patients, it is better to use combined CC, that is to say, manual CC should be adopted immediately in the early stage and then replace the mechanical CC device as soon as possible.

Effects between chest-compression-only cardiopulmonary resuscitation and standard cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: a Meta-analysis / 中华危重病急救医学

Objective To comprehensively evaluate and compare the resuscitation efficacy of chest-compression-only cardiopulmonary resuscitation (CCPR) and standard cardiopulmonary resuscitation (SCPR) for patients with out-of-hospital cardiac arrest (OHCA). Methods Databases such as PubMed, Embase, Ovid, Cochrane Library, Wanfang, CNKI, VIP, CBM were searched from the date of their foundation to March 2nd 2018, and the studies on the difference of effects between CCPR and SCPR for patients with OHCA were retrieved. The outcomes included the return of spontaneous circulation (ROSC) rate, survival to hospital discharge, neurological function completion rate. Two reviewers independently screened the literature meeting the inclusion criteria, independently collected information and evaluated the literature quality. Meta-analysis was conducted using RevMan 5.3 software, and sensitivity analysis was conducted by selecting model analysis method and removing single research method. Funnel plot was used to evaluate publication bias. Results A total of 10 cohort studies were included, including 174 163 patients with OHCA, of which 95 157 undergone CCPR and 79 006 undergone SCPR. The scores of the Newcastle-Ottawa scale (NOS) were 8-9, indicating that the quality of the literatures included was high. It was shown by the Meta-analysis that CCPR had the higher rate of survival to hospital discharge [relative risk (RR) = 1.04, 95% confidence interval (95%CI) = 1.00-1.08, P = 0.04] and neurological function completion (RR = 1.11, 95%CI = 1.06-1.17, P < 0.000 1) than SCPR, but there was no significant difference in ROSC rate between the two groups (RR = 1.01, 95%CI = 0.98-1.04, P = 0.52). In the subgroup, there was no statistical significance between CCPR and SCPR in the rate of survival to hospital discharge in cardiac OHCA patients (RR = 1.13, 95%CI = 0.82-1.57, P = 0.45). However, in non-cardiac OHCA group, SCPR showed more benefits than CCPR in improving the rate of survival to hospital discharge (RR = 0.88, 95%CI = 0.80-0.96, P = 0.004). The above analysis results were consistent in the fixed effect model and random effect model, indicating that the results were reliable and stable. It was shown by the funnel plot that most of the studies were left-right inverted funnel type, indicating a low publication bias. However, the bias could not be completely excluded due to the small number of included literatures. Conclusions For patients without OHCA etiological classification, CCPR was not less than SCPR in improving ROSC rate, discharge survival rate and good neurological function, and CCPR was more advantageous in learning and the willingness of bystanders to implement. However, when non-cardiogenic OHCA could be identified, SCPR should be recommended when conditions permit.

Protective effect of 5-aminosalicylic acid on the kidney of paraquat poisoning rats by Nrf 2-ARE signal pathway / 中华危重病急救医学

Objective To investigate the protective effect of 5-aminosalicylic acid (5-ASA) on renal injury poisoned by paraquat (PQ) in rats and its mechanism. Methods Twenty-four healthy clean male Sprague-Dawley (SD) rats were randomly divided into four groups: normal saline (NS) control group, 5-ASA control group, PQ model group and 5-ASA treatment group, with 6 rats in each group. The rat model of PQ poisoning was reproduced by intraperitoneal injection of 2% PQ solution 20 mg/kg, and the same volume of NS was given in NS control group and 5-ASA control group. Two hours later, the rats in 5-ASA control group and 5-ASA treatment group were intragastrically administered with 1 mL 5-ASA (75 mg/kg) for one time after NS or PQ administration, and those in NS control group and PQ model group were administered with 1 mL double distilled water. Behavioral changes were observed in rats. Then the rats were sacrificed at 24 hours after starting of the experiment for cardiac blood harvest which could be used to detect the biomarkers of renal injury and oxidative stress parameters. The kidney tissue was collected, and the hematein-eosin (HE) staining was conducted for observation of pathological changes in renal tissue, and protein expressions of Nrf 2 and heme oxygenase-1 (HO-1) were determined by Western Blot. Results At 30 minutes after PQ poisoning, rats appeared obvious poisoning symptoms and signs. Twenty-four hours after PQ poisoned, hemocoel of glomerular capillary, swelling of renal tubular epithelial cell and serious micronecrosis appeared under the light microscope. Compared with NS control group, blood urea nitrogen (BUN), serum creatinine (SCr), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and glutathione (GSH) levels were significantly abnormal in PQ model group, and Nrf 2 and HO-1 protein expressions in renal tissue were increased. After administration of 5-ASA, the morphological changes and pathological damage were mitigated as compared with those of PQ model group, the levels of BUN, SCr and MDA were decreased significantly [BUN (mmol/L): 11.98±1.81 vs. 18.56±2.32, SCr (μmol/L): 30.67±2.31 vs. 43.67±9.02, MDA (μmol/L):5.28±0.43 vs. 6.81±1.00], and the SOD activity, CAT and GSH contents were significantly increased [SOD (kU/L):125.49±7.63 vs. 106.76±7.94, CAT (ng/L): 30.68±3.51 vs. 23.05±1.55, GSH (μmol/L): 3.81±0.44 vs. 3.14±0.17], while the protein expressions of Nrf 2 and HO-1 were further increased [Nrf 2 protein (gray value): 0.76±0.04 vs. 0.52±0.03, HO-1 protein (gray value): 0.56±0.02 vs. 0.31±0.02, all P < 0.05]. Only 5-ASA intervention had no significant effect on behavior, pathology, renal injury markers and oxidative stress parameters, but it could induce the expressions of Nrf 2 and HO-1 protein in renal tissue, which were significantly higher than those of NS control group [Nrf 2 protein (gray value): 0.78±0.02 vs. 0.41±0.04, HO-1 protein (gray value): 0.51±0.03 vs. 0.23±0.01, both P < 0.01]. Conclusion 5-ASA attenuates the damage of acute renal injury (AKI) caused by PQ, which mechanism may be related with the activation of Nrf 2-antioxidant response element (ARE) signaling pathway.

Regularity of agonal respiration after untreated cardiac arrest in a swine model / 中华危重病急救医学

Objective To explore the regularity of incidence of agonal respiration (AR) and agonal respiration frequency rate (ARFR) during untreated cardiac arrest (CA) after ventricular fibrillation (VF) in a swine model.Methods Ten healthy male domestic pigs weighing (25.0± 3.0) kg were employed in this experiment.VF was induced by intraventricular shock with alternating current without treatment for 8 minutes.The incidence of AR and ARFR per minute were recorded for 8 minutes.Statistical analysis was performed using SPSS 19.0 system software.Results AR occurred in all animals after VF induced CA within 8 minutes.There was 1 animal showed AR at the first minute with ARFR (0.2±0.1) times/min,4 animals showed AR at the second minute with ARFR (1.2 ± 1.0) times/min,7 animals showed AR at the third minute with ARFR (2.7 ± 1.4) times/min,all animals showed AR at the fourth to fifth minute with ARFR (3.7 ± 1.6) times/min and (3.2 ± 1.9) times/min,7 animals showed AR at the sixth minute with ARFR (1.3 ± 1.0) times/min,no animal showed AR at the seventh minute,and 1 animal showed AR at the eighth minute with ARFR (0.2±0.1) times/min.The first and the last AR were observed at (2.02±0.84) minutes and (5.21 ± 1.12) minutes respectively.Occurrence of AR reached its peak at the fourth to fifth minute,and it was absent at the seventh minute.ARFR after CA showed a crescendo-decrescendo pattern,which increased from (0.2±0.1) times/min to (3.7±1.6) times/min followed by a fall to (0.2±0.1) times/min.Conclusions AR is one of the symbolic signs after CA.AR occurred in all animals during untreated VF,and it reaches its peak at the fomrth to fifth minute,with a crescendo-decrescendo pattern of ARFR.Effective identification and treatment in victim with AR timely can help to improve the success rate of cardiopulmonary resuscitation and survival rate.

Comparative study of sufentanil combined with dexmedetomidine on the awake patients with fiber bronchoscope intubation / 重庆医学

Objective To observe the effect of different doses of sufentanil on intubation guided by fiber bronchoscope in diffi‐cult airways .Methods One hundred and eighteen patients with difficult airways who underwent tracheal intubation were randomly divided into 3 groups [groupⅠ(n=40) ,groupⅡ (n=42) ,and groupⅢ (n=36)] .First all group received 1 μg/kg dexmedetomi‐dine ,then groupⅠ ,groupⅡ and group Ⅲ received sufentanil 0 .1μg/kg ,0 .2 μg/kg ,0 .3μg/kg infusion in bolus respectively .Heart rate(HR) ,mean arterial pressure(MAP)and saturation of pulse oximetry(SpO2 )were recorded at 5 min after patients arriving at operation room (T0 ) ,after drug infusion(T1 ) ,the time of intubation and seeing the epiglottis (T2 ) ,1 min(T3 )and 5 min(T4 )after intubation .side effect was recorded throughout the process .Results HR at T2 and T3 in groupⅡ and group Ⅲ were significantly lower than those in group Ⅰ(P<0 .05) .MAP at T2 and T3 in groupⅡ and group Ⅲ were significantly lower than those in groupⅠ(P<0 .05) .SpO2 at T2 in group Ⅲ was significantly lower than those of groupⅠ and groupⅡ(P<0 .05) .Cough reflex in groupⅠwas much frequent than others .Only group Ⅲ had respiratory inhibition .Conclusion Intravenous sufentanil (0 .2 μg/kg)could in‐hibit effectively stress reaction from endotracheal intubation ,in which less side effects such as haemodynamic changes and respirato‐ry depression occur .

Therapeutic effects of gastric lavage with fuller earth combined with QingyiⅡ catharsis in treatment of oral paraquat poisoning in rabbits / 中华危重病急救医学

ObjectiveTo observe the therapeutic effects of gastric lavage with fuller earth combined with QingyiⅡ catharsis in treatment of oral paraquat poisoning in rabbits.Methods Thirty healthy adult Japanese white rabbits were randomly divided into five groups: namely control group, model group, gastric lavage group (lavage of 10%fuller earth suspension), catharsis group (QingyiⅡ catharsis), and combination group (10 minutes after gastric lavage of fuller earth suspension liquid, giving QingyiⅡ for catharsis), with 6 rabbits in each group. All groups were challenged with paraquat (100 mg/kg) diluted to 5 mL with normal saline by lavage to reproduce the model of acute poisoning, while the control group was given 5 mL of normal saline instead. Each treatment group was treated accordingly at 1 hour after gavages of paraquat, and treatment continued for 3 days. The animal survival rate was observed. Venous blood samples were collected from ear marginal vein to determine the plasma concentration of paraquat by ultraviolet spectrophotometer at 1, 2, 4, 8 and 24 hours after the poisoning. The animals were sacrificed by intravenous air injection on the 8th day after the poisoning, and the right lower lobe of lung was harvested to observe the lung tissue pathological changes with hematoxylin-eosin (HE) staining.Results① Survival rate: the surviving rate of the combination group (6 rabbits) was higher than that of gastric lavage group (5 rabbits), catharsis group (2 rabbits) and model group (0 rabbit) on the 2nd day with statistically significant difference (P< 0.001). The survival rate on the 7th day in combination group (5 rabbits) was higher than that of gastric lavage group (3 rabbits), and catharsis group (0 rabbit) with statistically significant difference (P = 0.003).② Plasma concentrations of paraquat: plasma paraquat concentration in all groups peaked at 2 hours after intoxication, and its levels in the gastric lavage, catharsis and combination groups were significantly lower than that of the model group (mg/L: 1.830±0.068, 1.890±0.048, 1.800±0.052 vs. 1.960±0.063, allP< 0.01). As the time prolonged, the plasma concentration of paraquat was lowest in combination group than that of gastric lavage group and catharsis group (allP< 0.01). Gastric lavage and catharsis had interaction at 4 hours in combination group [F = 5.194,P = 0.034; the concentrations of paraquat (mg/L) was 0.670±0.057 vs. 1.010±0.018, 1.210±0.052].③ Lung histopathology: obvious expansion and hyperemia of the alveolar capillary, widened alveolar septum, a large number of inflammatory cell infiltrations were observed in model group and catharsis group. Lung histopathology was more improved in combination group and gastric lavage group, and it was improved more obviously in combination group than that in gastric lavage group.Conclusions Early start of gastric lavage with fuller earth combined with QingyiⅡ catharsis, can reduce the animal plasma concentrations of paraquat in oral paraquat poisoning rabbits. At the same time, it can alleviate the degree of lung injury and significantly improve survival rates compared with the single gastric lavage or catharsis alone. Gastric lavage with fuller earth combined with QingyiⅡ catharsis can improve the prognosis of animal synergistically.

Effects of spontaneous agonal respiration on coronary perfusion pressure during untreated cardiac arrest in swine model / 中华急诊医学杂志

Objective To investigate the effects of spontaneous agonal respiration on coronary perfusion pressure (CPP) during untreated cardiac arrest (ventricular fibrillation) in swine model.Methods Ten male healthy domestic swines (25.0 ± 1.5) kg were anaesthetised,intubated and mechanically ventilated.The catheterizations were separately inserted into the right atrium and thoracic aorta to monitor aortic pressure (AOP) and right atrial pressure (RAP).A pacing electrode was inserted into the right ventricle to induce ventricular fibrillation (VF).VF was induced by intra-ventricular stimulation withalternating electric current and untreated for 8 minutes.AOP and RAP were recorded until respiratory activity ceased.The CPP before and after agonal respiration was calculated and analyzed by paired-sample T test.Results All animals presented with agonal respiration from 1 to 6 minutes after VF during the first attempt.The CPP was (7.18 ±4.22) mmHg at 1 sec before agonal respiration,(11.78 ±5.16) mmHg at 0 sec after agonal respiration,(8.75 t:4.38) mmHg at 5 sec after agonal respiration and (8.23 ± 4.55)mmHg at 6 sec after agonal respiration.The CPP at 0 sec after agonal respiration was higher than that before agonal respiration (t =-3.140,P =0.012).The CPP at 5 sec after agonal respiration was higher than that at 1 sec before agonal respiration (t =-2.828,P =0.020).There was no difference in CPP between at 6 sec after agonal respiration and at 1 sec before agonal respiration (t =-1.778,P =0.109).Conclusions Agonal respiration accompanies ventricular fibrillation.After agonal respiration,the coronary perfusion pressure is increased for 5 seconds being in favor of cardiaopulmonary resuscitation.

Effects of sustained abdominal aorta compression-CPR on resuscitation of cardiac arrest in swines / 重庆医学

Objective To investigate the effects of sustained abdominal aorta compression (SAAC) method combined with sim-plex chest compression (SCC) on partial pressure of end-tidal CO2 (PETCO2 ) ,return of spontaneous circulation(ROSC) ,resuscita-tion success rate and 24 h survival rate of the cardiac arrest model in domestic swines .Methods 20 healthy domestic swines were randomly divided into two groups ;the standard cadiopulmonary resuscitation group (S-CPR) by adopting SCC and the SAAC-CPR group by adopting SCC combined with SAAC during the resuscitation process .The cardiac arrest model was established by the ven-tricular fibrillation induced through the right atrium electrode alternating current stimulation .After 9 min of untreated interval ,CPR was performed .The two groups were firstly given SCC ,after 30 s ,the SAAC-CPR group was added with SAAC .PETCO2 ,coronary perfusion pressure(CPP) ,ROSC rate ,resuscitation success rates ,and 24 h survival rate were compared between the two groups .Re-sults PETCO2 in the SAAC-CPR group was higher than that during the SCC period in the SAAC-CPR group and in the S-CPR group during CPR[(22 .50 ± 3 .17 )mm Hg vs .(11 .80 ± 2 .57) mm Hg ,(13 .40 ± 3 .53) mm Hg ,P<0 .01)] .CPP in the SAAC-CPR group was also higher than that during SCC in the SAAC-CPR group and the S-CPR group[(50 .30 ± 6 .49) mm Hg vs .(14 . 12 ± 3 .01)mm Hg ,(14 .62 ± 2 .59)mm Hg ,P<0 .01)] .3 cases in the S-CPR group and 9 cases in the SAAC-CPR group restored ROSC within 3 times defibrillation ,succeeded in resuscitation after 20 min ROSC and underwent 24 h survival .The ROSC rate ,the resuscitation success rate and the 24 h survival rate in the SAAC-CPR group were significantly higher than those in the S-CPR group(P<0 .05) .No abdominal viscera damage was found in post mortem examinations of all the swines subjects .Conclusion SAAC combined with SCC can elevate PETCO2 ,CPP ,ROSC ,resuscitation success rate and 24 h survival rate ,which is conducive to CPR ,safe and easy to operate .