Background: Cardiopulmonary resuscitation (CPR) strategies in COVID-19 patients differ from those in patients suffering from cardiogenic cardiac arrest. During CPR, both healthcare and non-healthcare workers who provide resuscitation are at risk of infection. The Working Group for Expert Consensus on Prevention and Cardiopulmonary Resuscitation for Cardiac Arrest in COVID-19 has developed this Chinese Expert Consensus to guide clinical practice of CPR in COVID-19 patients. Main recommendations: 1) A medical team should be assigned to evaluate severe and critical COVID-19 for early monitoring of cardiac-arrest warning signs. 2) Psychological counseling and treatment are highly recommended, since sympathetic and vagal abnormalities induced by psychological stress from the COVID-19 pandemic can induce cardiac arrest. 3) Healthcare workers should wear personal protective equipment (PPE). 4) Mouth-to-mouth ventilation should be avoided on patients suspected of having or diagnosed with COVID-19. 5) Hands-only chest compression and mechanical chest compression are recommended. 6) Tracheal-intubation procedures should be optimized and tracheal-intubation strategies should be implemented early. 7) CPR should be provided for 20-30 min. 8) Various factors should be taken into consideration such as the interests of patients and family members, ethics, transmission risks, and laws and regulations governing infectious disease control. Changes in management: The following changes or modifications to CPR strategy in COVID-19 patients are proposed: 1) Healthcare workers should wear PPE. 2) Hands-only chest compression and mechanical chest compression can be implemented to reduce or avoid the spread of viruses by aerosols. 3) Both the benefits to patients and the risk of infection should be considered. 4) Hhealthcare workers should be fully aware of and trained in CPR strategies and procedures specifically for patients with COVID-19.

Objective To evaluate the role of group Ⅱ metabotropic glutamate receptors (mGluRs) in cognitive decline caused by multiple administrations of ketamine in mice and the relationship with hippocampal glycogen synthase kinase-3 beta (GSK-3β) expression.Methods Forty-five SPF healthy female C57BL/6 mice,aged 6-8 weeks,weighing 20-30 g,were randomized into 3 groups (n=15 each) using a random number table method:control group (group C),ketamine group (group K) and mGluR agonist LY354740 group (group L+K).In K and L+K groups,ketamine 30 mg/kg was intraperitoneally injected three times a day at an 30-min interval for 14 consecutive days.LY354740 was intraperitoneally injected at 30 min before the first injection of ketamine in group L+K.The equal volume of normal saline was given instead in group C.Morris water maze test was performed the day after the last administration.The mice were then sacrificed,and hippocampi were harvested to determine the expression of GSK3β,NR2A and postsynaptic density protein 95 (PSD95) by Western blot.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,the frequency of crossing the original platform was decreased,the expression of GSK3β3 and NR2A was up-regulated,and the expression of PSD95 was down-regulated in group K (P＜0.05),and no significant change was found in the parameters mentioned above in group L+K (P＞0.05).Compared with group K,the escape latency was significantly shortened,the time of staying at the original platform quadrant was prolonged,the frequency of crossing the original platform was increased,the expression of GSK3β and NR2A was down-regulated,and the expression of PSD95 was up-regulated in group L+K (P＜0.05).Conclusion Group Ⅱ mGluRs are involved in the process of cognitive decline caused by multiple administrations of ketamine in mice,which is associated with up-regulated expression of hippocampal GSK-3β.

The laterodorsal tegmentum (LDT) is a brain structure involved in distinct behaviors including arousal, reward, and innate fear. How environmental stimuli and top-down control from high-order sensory and limbic cortical areas converge and coordinate in this region to modulate diverse behavioral outputs remains unclear. Using a modified rabies virus, we applied monosynaptic retrograde tracing to the whole brain to examine the LDT cell type specific upstream nuclei. The LDT received very strong midbrain and hindbrain afferents and moderate cortical and hypothalamic innervation but weak connections to the thalamus. The main projection neurons from cortical areas were restricted to the limbic lobe, including the ventral orbital cortex (VO), prelimbic, and cingulate cortices. Although different cell populations received qualitatively similar inputs, primarily via afferents from the periaqueductal gray area, superior colliculus, and the LDT itself, parvalbumin-positive (PV) GABAergic cells received preferential projections from local LDT neurons. With regard to the different subtypes of GABAergic cells, a considerable number of nuclei, including those of the ventral tegmental area, central amygdaloid nucleus, and VO, made significantly greater inputs to somatostatin-positive cells than to PV cells. Diverse inputs to the LDT on a system-wide level were revealed.

Objective Based on OpenSim platform, an improved musculoskeletal model was developed to analyze the force of lumbar muscle groups under forward flexion. Methods The existing lumbar musculoskeletal model was improved via modifying constraints of lumbar vertebrae to restore them into 6 degrees of freedom (DOF). The 30 year-old and 70 year-old muscle models were established respectively by adjusting muscle parameters according to Thelen’s model, adding stiffness matrixes and abdominal pressure (AP) characterized by concentrated force to investigate the effects of arm swing, movement velocity, varying AP and muscle aging on the force distribution of 9 lumbar muscle groups during forward flexion. Results A multi-body musculoskeletal model with 9 lumbar muscle groups was developed. Based on the computations of 0°-70° flexion, the results showed that arm swing reduced the force of psoas and external oblique abdominis, while under the movement of forward flexing to 70° and returning up-right, the force of psoas, erector spinae, rectus and external oblique abdominis obviously increased, when the time of flexing-returning process was reduced from 5 s to 2.5 s, and in the 5 s case, increasing AP reduced the force of psoas but increased the force of transversus, internal and external oblique abdominis. In the 2.5 s case, there was no obvious difference between the 30 year-old and 70 year-old muscle models under different conditions. Conclusions The developed model provides an effective method to analyze the force of lumbar spine and muscles, and it certainly shows a potential application in the fields of kinematic mechanics and rehabilitation engineering with further development of basic theory.

Objective To evaluate the role of nuclear factor kappa B (NF-κB) in cognitive decline in aged mice with sepsis.Methods Forty-five SPF healthy aged female C57BL/6 mice,aged 10-12 months,weighing 20-30 g,were assigned into 3 groups (n=15 each) using a random number table:control group (group C),sepsis group (group Sep) and NF-κB selective inhibitor pyrrolidine dithiocarbamate (PDTC) group (group PDTC).Lipopolysaccharide 250 μg/kg was injected intraperitoneally once a day for 7 consecutive days in Sep and PDTC groups,and in addition PDTC 50 mg/kg was injected intraperitoneally at 30 min before lipopolysaccharide injection once a day for 7 consecutive days in group PDTC.The equal volume of normal saline was given in group C.Five mice in each group were sacrificed at 2 h after the last administration,cardiac puncture was performed and blood samples were collected,and then the mice were sacrificed and hippocampi were harvested for determination of the levels of tumor necrosis factor-α (TNF-α),interleukin-1β (IL-1β) and IL-6 in plasma and hippocampal tissues using enzyme-linked immunosorbent assay.Cognitive function was assessed using open field,elevated plus maze and Morris water maze tests at 24 h after the last administration in the other mice left in each group.Results Compared with group C,the levels of TNF-α,IL-1β and IL-6 in plasma and hippocampal tissues were significantly increased,the time of movement at the central region was shortened,the percentage of time spent in the open arms and number of entries into the open and closed arms were decreased,the escape latency was prolonged,the time of staying at the original platform quadrant was shortened,and the frequency of crossing the platform was decreased in group Sep (P＜0.05).Compared with group Sep,the levels of TNF-α,IL-1β5 and IL-6 in plasma and hippocampal tissues were significantly decreased,the time of movement at the central region was prolonged,the percentage of time spent in the open arms and number of entries into the open and closed arms were increased,the escape latency was shortened,and the time of staying at the original platform quadrant was prolonged in group PDTC (P＜0.05).Conclusion NF-κB is involved in cognitive decline in aged mice with sepsis.

Objective To evaluate the efficacy of pressure support ventilation ( PSV ) in the infants undergoing laparoscopic hernia repair under sevoflurane anesthesia. Methods Thirty ASA physical statusⅠpediatric children, aged 9 months-1 yr, weighing 8.0-11.5 kg, undergoing elective laparoscopic hernia repair, were randomly assigned into 3 groups ( n=10 each) using a random number table: pressure control ventilation ( PCV) used for muscle relaxants in combination with low?concentration sevoflurane group ( group PCV1 ) , PCV used for high?concentration sevoflurane group ( group PCV2 ) , and PSV used for low?concentration sevoflurane group ( group PSV) . Anesthesia was induced with inhalation of 4%-6%sevoflurane and iv fentanyl 2 μg∕kg and succinylcholine 1.5 mg∕kg. The pediatric children were endotracheally intubated and mechanically ventilated. In PCV1 and PCV2 groups, PCV was used during operation. In group PSV, PCV was used first after intubation, and then PSV was applied after spontaneous breathing recovered. Anesthesia was maintained as follows: in group PCV1 , the end?tidal concentration of sevoflurane was maintained at 2.5% - 3.0%, and cisatracurium besylate 0.1 mg∕kg was injected intermittently as required; in group PCV1 , the end?tidal concentration of sevoflurane was maintained at 3.5%-4.0%; in group PSV, the end?tidal concentration of sevoflurane was maintained at 2.5%-3.0%, and succinylcholine 1.0 mg∕kg was injected intravenously before pneumoperitoneum. Narcotrend index value was maintained at 50-60 in PCV1 and PSV groups, or at 37-45 in PCV2 group. Heart rate ( HR) and mean arterial pressure (MAP) were recorded before induction of anesthesia (baseline), at the beginning of pneumoperitoneum, at 5 and 10 min of pneumoperitoneum, at the end of pneumoperitoneum, at the end of operation and immediately after extubation. The time interval from the end of surgery to extubation was recorded. Results Pulse oxygen saturation was 100% during anesthesia, and>95% during recovery from anesthesia in the three groups. Compared with the baseline value, HR was significantly faster, and MAP was increased during extubation in PCV1 and PCV2 groups, and no significant change was found in HR and MAP at each time point in group PSV. The time interval from the end of surgery to extubation was 30.3± 5.4, 18.4±4.3 and (4.1±1.2) min in PCV1, PCV2 and PSV groups, respectively. Compared with PCV1 and PCV2 groups, the time interval from the end of surgery to extubation was significantly shortened in group PSV. Conclusion When PSV is applied in the infants undergoing laparoscopic hernia repair under sevoflurane anesthesia, it can provide adequate ventilation, recovery from anesthesia is rapid, and no cardiovascular responses occur during extubation.