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Objective To study the incidence,possible risk factors,and influence on patient outcomes of diaphragmatic dysfunction in patients after surgical treatment of type A aortic dissection using ultrasound.Methods Patients who received replacement of hemiarch or total arch with concomitant procedures concerning aortic pathology,and an elephant trunk procedure for the descending aorta were prospectively enrolled in this study from February to May 2017.After surgery,they were transferred to the cardiac surgical intensive care unit.They were divided into two groups based on diaphragmatic excursion:diaphragmatic dysfunction (DD) group and diaphragmatic function normal (DN) grouBilateral diaphragmatic excursions were evaluated using ultrasound during spontaneous breathing trial by T-tube.The differences in demographic characteristics,operation-related variables and outcomes were compared between the two groups.Results A total of 42 patients were enrolled in this study,and 32 of them suffered from diaphragmatic dysfunctions.Compared with DN group,the excursion of the influenced diaphragm in DD group was significantly reduced[(0.450 ± 0.331)cm vs.(1.801 ± 0.616)cm,P＜0.01],while the excursion of the non-influenced diaphragm was not reduced[(2.013±0.655)cm vs.(1.801 ±0.616) cm,P=0.254].Diaphragmatic thickness was comparable [(0.184±0.028)cm vs.(0.189±0.028)cm,P=0.559 ] between the two groups while thickening fraction was significantly reduced in DD group[(4.67％±3.63)％ vs.(23.58％±10.69)％,P＜0.01].Meanwhile,respiratory rate was significantly higher in DD group as compared to DN group [(24.13 ± 4.98)times/min vs.(20.50 ± 3.17)times/min,P=0.037].Patients in DD group showed longer cross-clamp duration[(121.78±27.75)min vs.(93.10±18.84)min,P=0.004] and longer cardiopulmonary bypass duration [(208.09±32.78)min vs.(182.70±24.38)min,P=0.03] than patients in DN grouFurthermore,binary logistic analysis indicated that longer cross-clamp duration was the potential risk factor for diaphragmatic dysfunction after type A aortic dissection surgery.Mechanical ventilation duration was longer in DD group than in DN group (88 h vs.37 h,P=0.194) but without statistical significance.The usage of noninvasive ventilation was significantly increased in DD group as compared to DN group (46.88％ vs.10％,P=0.036).Other outcomes such as post-operative complications,mortality,ICU length of stay were comparable between the two groups.Conclusions Diaphragmatic dysfunction was very common after surgical treatment of type A aortic dissection.Longer duration of cross-clamp was considered as a potential risk factor of diaphragmatic dysfunction.A sequential management of noninvasive ventilation after extubation was feasible for diaphragmatic dysfunction after surgical treatment of type A aortic dissection.
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Objective To investigate the efficacy of dexmedetomidine on sedation in post-cardiac surgery patients with NIV intolerance.The changes of respiratory function and hemodynamics of the patients as well as non-invasive ventilation (NIV) failure rate were also under evaluation.Methods Thirty-five post-cardiac surgery patients with NIV intolerance and hypoxemia were enrolled in this prospective study.All patients were sedated with dexmedetomidine.NIV was standardized according to the uniform protocol.The main outcome was NIV success (avoiding endotracheal intubation) or NIV failure (requiring endotracheal intubation or die).The cardiorespiratory parameters (BP,HtR and RR) and artery blood gas analysis were prospectively recorded before and after sedation.The respiratory function and hemodynamics changes in both groups (NIV success group and NIV failure group) were then evaluated.Factors independently associated with NIV failure were identified using a logistic regression model.Results Twenty out of 35 patients (57.14％) survived while 15 (42.86％) patients failed NIV.After 1 h and 4 h of NIV with dexmedetomidine sedation,respiratory rate in both groups were decreased compared with baseline,especially in NIV success group.The PaO2/FiO2 was also improved after 1h and 4h of NIV treatment compared with baseline.The improvement was more significantly in NIV success group.The heart rate was decreased compared with baseline with no differences between two groups.There were no significant changes on PaCO2 and mean arterial pressure (MAP) during the treatment.The respiratory and hemodynamics variables identified as predictors of NIV failure were included in a multivariate logistic regression.RR ＞ 23 time/min (OR =3.2,95％ CI:2.043 ～ 4.301,P ＜ 0.01) 1 h after NIV,RR ＞ 20 time/min (OR =2.1,95％ CI:1.659～3.231,P=0.025) 4 h after NIV,PaO2/FiO2 ＜178 mmHg (OR=2.4,95％CI:1.892 ～ 3.287,P ＜0.01) 1 h after NIV and PaO2/FiO2 ＜ 185 mmHg (OR =1.7,95％ CI:1.243 ～ 2.365,P =0.041) 4 h after NIV independendy predicted NIV failure.Conclusions Dexmedetomidine might be considered as an effective and safe sedative for post-cardiac surgery patients with NIV intolerance.Early identification of predictors of NIV failure may facilitate early intervention.
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Objective:To observe the effect of ketogenic diet on the growth of human colon cancer cells in nude mice and to de-termine its possible mechanisms. Methods:A total of 24 male BALB/C nude mice were injected subcutaneously with the tumor cells of the colon cancer cell line HCT116. These animals were randomized into two feeding groups. One group was fed with a ketogenic diet (KD group;n=12), and the other group was given a standard diet (SD group;n=12) ad libitum. Experiments were completed upon at-taining a target tumor volume of 600 mm3 to 700 mm3. The two diets were compared based on body weight, serum glucose, ketone body, insulin, tumor growth, and survival time, which is the interval between tumor cell injection and attainment of target tumor vol-ume. Results:The tumor growth was significantly more delayed in the KD group than in the SD group. Tumors in the KD and SD groups reached the target tumor volume at 33.8 ± 6.7 days and 24.8 ± 3.1 days, respectively. The ketone body in the KD group was ele-vated with a slight reduction in serum insulin, and the difference in serum glucose in the two groups was insignificant. Importantly, the KD group had significantly larger necrotic areas and less vessel density than the SD group. Conclusion:The application of an unre-stricted ketogenic diet delayed tumor growth in a mouse xenograft model. Further studies are needed to address the mechanism of this diet intervention and its effect on other tumor-relevant functions, such as invasive growth and metastasis.