Objective To investigate the influence of two different mechanical ventilation modes of bi-level positive airway pressure ventilation(BIPAP)and synchronized intermittent ventilation (SIMV)on the respiratory function and clinical curative effect in children patients with severe hand foot and mouth disease(HFMD)complicating neurogenic pulmonary edema.Methods Thirty children patients with severe HFMD complicating neurogenic pulmonary edema receiving mechanical ventilation were divided into the SIMV group (control group)and BIPAP group (experimental group).The lung protective ventilation strategy was applied in both groups.After 30 min use of SIMV and positive end expiratory pressure (PEEP)ventilation,the experimental group changed to use the BIPAP ventilation mode,while the control group still used the initial parameters.The airway peak pressure,alveolar plat-form (Pplat)pressure,lung compliance,pH value,arterial blood CO2 partial pressure (PaCO2 )and oxygenation index (PaO2/FiO2 )at 0 h (baseline value),24,48,72 h after mechanical ventilation were monitored.Besides,the duration of mechanical ventila-tion,28 d mortality rate and the length of ICU stay were observed.Results Thirty children patients smoothly spent their acute re-spiratory failure period.One case in each group during the later period of treatment was transferred to the other hospital for contin-uous therapy.Among them the transferred case in the control group finally died due to give up treatment.The rest 28 cases all were cured and discharged from hospital.The 28 d mortality rates in the two groups were 6.67% and 0% respectively,with no statistical difference (P >0.05).Compared with the control group,the airway peak pressure,Pplat and PaCO2 after mechanical ventilation for 24,48,72 h in the experimental group were significantly decreased(P <0.05);the lung compliance and PaO2/ FiO2 improvement was significantly higher than that in the control group(P <0.05);meanwhile the duration of mechanical ventilation and the length of ICU stay in the experimental group were shorter than those in the control group (P <0.05).Conclusion The BIPAP mode used in the mechanical ventilation therapy of the children patients with severe HFMD complicating neurogenic pulmonary edema can pro-vide better effective ventilation,improve oxygenation and respiratory function,and shorten the duration of mechanical ventilation.

Frailty is a syndrome characterized by vulnerability to stressors due to loss of physiological reserve. In recent years, many researches have confirmed that frailty is a risk factor for postoperative complications of cardiac surgery, such as readmission, adverse cardiovascular events, and death in elderly patients. This paper reviews the concept of frailty, the relationship between frailty and cardiac surgery, the frailty assessment and intervention strategy in perioperative period, aimed at providing decision making basis for the risk stratification and perioperative management of cardiac surgery in elderly patients.

Objective    To systematically evaluate the risk factors for hypoxemia after coronary artery bypass grafting (CABG). Methods    Eight electronic databases including PubMed, EMbase, CENTRAL, Web of Science, CNKI, CBM, VIP and Wanfang data were searched by computer to collect cochort and case-control studies about CABG and hypoxemia published from inception to March 2020. Two authors independently assessed the quality using the Newcastle-Ottawa Scale (NOS), and a meta-analysis was performed by RevMan 5.3 software. Results    A total of 15 studies involving 4 277 patients were included in this study and among them 1 273 patients suffered hypoxemia. Meta-analysis showed that age (OR=1.55, 95%CI 1.22 to 1.96, P=0.000 3), smoking (OR=3.22, 95%CI 2.48 to 4.17, P<0.000 01), preoperative chronic pulmonary diseases (OR=4.75, 95%CI 3.28 to 6.86, P<0.000 01), diabetes (OR=2.49, 95%CI 1.86 to 3.33, P<0.000 01), left ventricular ejection fraction (OR=3.15, 95%CI 2.19 to 4.52, P<0.000 01), number of coronary artery lesions (OR=2.20, 95%CI 1.63 to 2.97, P<0.000 1) were independent risk factors for hypoxemia after CABG; body mass index (OR=1.31, 95%CI 0.97 to 1.77, P=0.08) and cardiopulmonary bypass time (OR=3.40, 95%CI 0.72 to 15.94, P=0.12) were not associated with hypoxemia. Conclusion    Current evidence shows that age, preoperative chronic pulmonary diseases, smoking, diabetes, left ventricular ejection fraction, number of coronary artery are risk factors for hypoxemia after CABG, which can be used to identify high-risk patients and provide guidance for medical staff to develop perioperative preventive strategies to reduce the incidence of hypoxemia. The results should be validated by large-scale standard studies in the future.

Objective     To systematically evaluate the risk factors for hypoxemia after Stanford type A aortic dissection (TAAD) surgery. Methods     Electronic databases including PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP and CBM were searched by computer to collect studies about risk factors for hypoxemia after TAAD published from inception to November 2021. Two authors independently assessed the studies' quality, and a meta-analysis was performed by RevMan 5.3 software. Results    A total of 19 case-control studies involving 2 686 patients and among them 1 085 patients suffered hypoxemia, included 21 predictive risk factors. The score of Newcastle-Ottawa scale≥7 points in 16 studies. Meta-analysis showed that: age (OR=1.10, 95%CI 1.06 to 1.14, P<0.000 01), body mass index (OR=1.87, 95%CI 1.49 to 2.34, P<0.000 01), preoperative partial pressure of oxygen in arterial blood/fractional concentration of inspiratory oxygen (PaO2/FiO2)≤300 mm Hg (OR=7.13, 95%CI 3.48 to 14.61, P<0.000 01), preoperative white blood cell count (OR=1.34, 95%CI 1.18 to 1.53, P<0.000 1), deep hypothermic circulatory arrest time (OR=1.33, 95%CI 1.14 to 1.57, P=0.000 4), perioperative blood transfusion (OR=1.89, 95%CI 1.49 to 2.41, P<0.000 01), cardiopulmonary bypass time (OR=1.02, 95%CI 1.00 to 1.03, P=0.02) were independent risk factors for hypoxemia after TAAD surgery. Preoperative serum creatinine, preoperative myoglobin, preoperative alanine aminotransferase were not associated with postoperative hypoxemia. Conclusion     Current evidence shows that age, body mass index, preoperative PaO2/FiO2≤300 mm Hg, preoperative white blood cell count, deep hypothermic circulatory arrest time, perioperative blood transfusion, cardiopulmonary bypass time are risk factors for hypoxemia after TAAD surgery. These factors can be used to identify high-risk patients, and provide guidance for medical staff to develop perioperative preventive strategy to reduce the incidence of hypoxemia. The results should be validated by higher quality researches.

Objective    To analyze the changes of perioperative thyroid hormone in patients undergoing cardiac surgery under cardiopulmonary bypass, and to provide guidance for postoperative cardiac management. Methods    The clinical data of 72 patients receiving cardiac surgery under cardiopulmonary bypass in our hospital from January to May 2019 were collected, including 35 males and 37 females, aged 19-72 (52.35±10.40) years. The changes of thyroid hormones before operation, 2 hours and 24 hours after operation were analyzed. Results    There was a statistical difference in thyroid stimulating hormone (TSH), triiodothyronine (T3), tetraiodothyronine (T4) and free tetraiodothyronine (FT4) between postoperative 2 hours and preoperation (P<0.05). There was a statistical difference in TSH, T3, free triiodothyronine (FT3), T4 and FT4 between postoperative 24 hours and preoperation (P<0.05). There was a statistical difference in TSH, T3, FT3 and T4 between postoperative 24 hours and 2 hours (P<0.05). Postoperatively T3 and FT3 decreased, TSH increased and then decreased while T4 and FT4 were within the normal range. Repeated measures analysis of variance showed a statistical difference of time effect in TSH, T3, FT3, T4 and FT4. Conclusion    Patients with cardiac surgery under cardiopulmonary bypass have different thyroid hormones postoperatively compared with preoperatively. T3 and FT3 decrease, TSH increases and then decreases, while T4 and FT4 are in the normal range. The results require further large-scale, multi-center, high-quality clinical studies to be confirmed.