AIM: To investigate the effects of non-invasive ischemic preconditioning on nitric oxide (NO)/endothelin-1 (ET-1) imbalance and gas exchange impairment following limb ischemia reperfusion in patients undergoing unilateral lower extremity surgery with tourniquet. METHODS: Twenty-seven patients aged 25-65 years, whose tourniquets duration varied from 1 h to 1.5 h and matched American Society of Anesthesiologists Physical Status Ⅰ-Ⅱ, were randomized into two groups: a control group (n=14) and a ischemic preconditioning group (IPC group, n=13) in which patients received three cycles of 5 min of ischemia/5 min of reperfusion before tourniquet inflation. Radial arterial blood gas, plasma malondialdehyde (MDA) and NO, serum ET-1 and interleukin-6 (IL-6) were measured just before tourniquet inflation(T_0), 1 h after inflation(T_1), and 0.5 h(T_2), 2 h(T_3), 6 h(T_4), 24 h(T_5) after tourniquet deflation. Meanwhile NO/ET-1 ratio, alveolar-arterial oxygen gradient (P_(A-a)DO_2) and intrapulmonary shunt (Qs/Qt) were calculated. RESULTS: In control group, arterial partial pressure of oxygen (PaO_2) were decreased, while P_(A-a)DO_2 and Qs/Qt were increased significantly at T_4 compared to the baselines at T_0 (P<0.01). Plasma NO levels and NO/ET-1 ratios decreased gradually after tourniquets deflation and statistical significances were observed at T_3 (P<0.01) with a valley at T_4 (P<0.01) and recovered to baselines at T_5. Serum ET-1, IL-6 and plasma MDA began to increase remarkably after T_3 (P<0.05 or P<0.01), peaked at T_4 and dropped slightly at T_5. The changes above-mentioned could be well attenuated by the application of IPC (P<0.05 or P<0.01) except PaO_2 (P>0.05). CONCLUSION: Clinical application of unilateral tourniquet within safe time limit (1.5 h) may lead to limb ischemia reperfusion and further pulmonary gas exchange impairment, which could be partially attenuated by the application of IPC via alleviating NO/ET-1 imbalance.

Objective: To investigate the status of depression and anxiety symptoms in mothers with autistic child, and explore the association between coping styles and emotional problems.To provide theoretical evidence of mental health intervention for mothers with autistic children. Methods: A cross-section study was conducted in three autism rehabilitation centres of Changsha city.A total of 135 mothers of autistic child were recruited from March to November 2018.The self-designed questionnaires, patient health questionnaire-9 (PHQ-9), generalized anxiety disorder scale-7 (GAD-7), simple coping style questionnaire(SCSQ) and autism behaviour checklist(ABC) were used in the study.Spearman analysis was used to explore the correlation between emotional problems and copying styles.The ordinal logistic regression was conducted to explore the impact of the coping styles for emotional problems. Results: The scores of anxiety and depression symptoms were 9.0 (5.0, 13.0) and 7.0 (3.0, 11.0), respectively.The occurrence rate of anxiety and depression symptoms was 44.5% and 28.1%, respectively.The scores of positive and negative coping were (1.75±0.90) and (1.05±1.03), respectively.There were 72 (53.3%) and 63 (46.7%) of participants adopted positive and negative coping styles, respectively.There was a positive correlation between negative coping and anxiety symptoms (r=0.182, P<0.05). There was a negative correlation between positive coping and depression symptoms (r=-0.184, P<0.05). The ordinal logistic regression showed positive coping was a protective factor for anxiety symptoms (OR=0.444, 95%CI: 0.205-0.965). Conclusion The anxiety and depression symptoms are common problems in mothers of children with ASD.It is necessary to take suitable psychological interventions to encourage them to adopt positive copying styles.