The influence of acute and intermittent hypoxia on respiratory mechanics in the range of tidal volume of adult rabbits was studied. All is based on the assumption that the tissue structure of lung constitutes a conservative mechanical system and hence that pressure(P)-volume(V)hysteresis is primarily a result of surface tension(r)-surface area(s)hysteresis. It was found that the lung compliance of rabbits to acute hypoxia was decreased and respiratory work increased. Compared to control group (3.5?1.1mm),the working limbs of P-V loops of acute hypoxic rabbits increased by 49% (5.2?0.6mm). Such changes could be corrected in part by appropriate intermittent hypoxia, the length of working limbs of 5-day adaptation rabbits was 4.2?1.1(P

Objective To evaluate the effectiveness and safety of dexmedetomidine for the sedation of the patients after coronary artery bypass grafting (CABG).Methods The selective 96 CABG patients,ASA Ⅱor Ⅲ,aged 36 to 68 years old,58 males and 38 females,were randomly divided into 2 groups (n =48):dexmedetomidine group (group A) and midazolam group (group B).Group A patients received Dexmedetomidine (1.0 μg/kg)over 10 min,followed by 0.2-0.7 μg · kg-1 · h-1 to maintain sedation,whereas the other group patients received midazolam (0.05 mg/kg) over 10 min,followed by 0.02-0.10 mg · kg-1 · h-1 to maintain sedation.Two groups of patients stopped using drug when they were fit off-line and extubation.Observe the percentage of time within target sedative scope (Riker range 3-4),the changes of vital signs before and after treatment,the prevalence of delirium,the awakening time,the duration of mechanical ventilation,ICU length of stay,the adverse events of blood pressure and heart rate.Results There were no significant difference in the percentage of time within target sedative scope between two groups (75.5％ for dexmedetomidine group vs 74.6％ for midazolam group,P ＞ 0.05).Compared to midazolam group,the Dexmedetomidine group has a shorter awakening time [(14.0 ± 6.2) min for dexmedetomidine group vs (50.4 ± 12.8) min for midazolam group,P ＜ 0.05] and duration of mechanical ventilation,and also the prevalence of delirium was lower(15.3％ for dexmedetomidine group vs 34.6％ for midazolam group,P ＜0.05).ICU length of stay was similar.Dexmedetomidine-treated patients were more likely to develop bradcardia,with a non significant increase in the proportion requiring treatment,but had a lower likelihood of tachycardia or hypertension requiring treatment.Conclusion Dexmedetomidine is safe and effective in patients after CABG surgery.

BACKGROUND: Studies have shown that basic fibroblast growth factor has effects on stimulating vessel regeneration and collateral reconstruction. However, administration was performed mostly by peripheral vein, left atrium or percutaneous coronary intervention, and it is difficult to achieve an effective therapeutic concentration in the local myocardium. OBJECTIVE: Based on the property of poly(D, I-lactic-coglycolic acid) (PLGA), to investigate outcomes of inducing neovascularization in the myocardium in combination of basic fibroblast growth factor (bFGF) by ensuring target release of protein growth factor in local tissue. METHODS: PLGA and bFGF were dissolved in dichloromethane. This liquid mixture was rolled into the form of a hollow tube (3.0 mm outer diameter, 2.8 mm inner diameter, 0.1 mm thick, 10 mm length) for further use. The middle third of the left anterior descending coronary artery of mini-swines was ligated, and the local myocardium became dark purple. After the successful establishment by abnormal regional wall motion in the cardiac apex at anterior wall using ultrasound, the mini-swines were assigned to channels and bare scaffolds (BS) group and channels and bFGF-incorporating scaffolds (FS) group. The scaffold was implanted in the myocardium using self-made hollow bit. At 6 weeks, the number of proliferative cells was quantified by immunohistochemical staining. New vessels were quantified utilizing Image-Pro Plus software package in both groups. Quantitative analysis of changes in mass defect percentage was performed by Emory Cardiac Toolbox software combined with single-photon-emission computed tomography. RESULTS AND CONCLUSION: At 6 weeks, number of proliferative cells and the density of new vessels were significantly increased in the FS group compared with BS group(P<0.001). Single-photon-emission computed tomography illustrates that MDP was significantly lower in the FS group compared with the BS group (P < 0.001). Results have suggested that PLGA scaffolds that incorporate bFGF were able to induce angiogenesis and enhance blood-flow perfusion.

Objective This study aims to analyze the independent risk factors associated with postoperative delirium of patients undergoing Stanford A aortic dissection surgery.Methods Clinical data of the patients who underwent Stanford A aortic dissection surgery from December 2014 to October 2015 were collected.All patients received surgery under deep hypothermic circulatory arrest(DHCA) and the nasal temperature goal was below 23℃.After surgery,patients were transferred to the cardiovascular ICU,where they received standard postoperative care.The delirium was diagnosed according to the criteria of the confusion assessment method for the intensive care unit(CAM-ICU).The possible risk factors of pre-operation,during operation or post-operation were analyzed via univariate analysis and multivariate logistic regression to determine the independent risk factorsof postoperative delirium.Results 148 patients underwent Stanford A aortic dissection surgery which the incidence of postoperative delirium was 31.1％ (46/148).Univariate analysis showed the associated risk factors were age,hypertension,cognitive impairment,emergency operation,operation time,aorta clamping time,DHCA time,fluctuation of blood pressure during operation,blood transfusion,quality of sleep,length of ICU stay and electrolyte disturbance(P ＜ 0.05).Multivariate logistic regression analysis revealed that hypertension,cognitive impairment,fluctuation of mean arterial blood pressure(MAP) ＞ 30 mmHg (1 mmHg =0.133 kPa),DHCA time ＞ 40 min,postoperative poor quality of sleep and electrolyte disturbance were independently associated with postoperative delirium after Stanford A aortic dissection surgery(P ＜ 0.05).Conclusion Delirium is a frequent complication.Factors independently associated with delirium are hypertension,cognitive impairment,DHCA time,postoperative poor quality of sleep and electrolyte disturbance.Prevent,assess and manage delirium should be paid more attention and reinforced.

Objective To discuss the clinical epidemiology features and change trend of aortic dissection (AD) in Henan Province.Methods Retrospective analysis of consecutive 906 patients with AD over 10 years in Henan Provincial People' s Hospital,the First Affiliated Hospital of Zhengzhou University and Henan Provincial Chest Hospital.Hospital records and prognosis were compared between two five-year periods.Results 906 cases with AD were hospitalized during the past 10years.The mean age was (50.2 ± 9.8) years.The male/female ratio was 3.49 ∶ 1.Hypertension was present in 60.3 ％ of all patients.Heavy smoking history was elicited in 32.2％ of all patients.Type A dissection were identified in 57.8％ of all the cases,and type B in 42.2％.In-hospital mortality of acute type A dissection was 21.8％,acute type B dissection 6.8％.In two five-year periods,the total number of cases increased by 216％,among which type A was the fastest,increased by 294％,Changes of mean age and male/female ratio were not significant.For acute AD,changes of prognosis in one year improved,and reach statistical significance (P ＜ 0.05).Conclusion This study provides insight into current regional profiles of AD.The number of hospitalized patients with AD is increasing dramatically.The mean age of the first-attack is much younger and the male ration is much higher than that reported by other regional researchers.These data support the urgent need for further improvement in prevention and treatment of AD.

Objective To investigate the correlation between carotid artery plaque and blood pressure variability (BPV) in elderly patients with hypertension.Methods One hundred sixty elderly patients with hypertension were divided into plaque and non-plaque groups according to the results of carotid artery ultrasonography.All the patients were measured by ambulatory blood pressure monitoring.The mean blood pressure,mean pulse pressure,and blood pressure variability coefficient of two groups were calculated and compared during whole day,daytime,and nighttime.The related factors of carotid artery plaque were analyzed by multivarite logistic regression analysis.Results The 24 h systolic blood pressure standard deviation,daytime and nighttime of systolic blood pressure standard deviation,daytime diastolic blood pressure standard deviation of plaque group were higher than those of non-plaque group (P ＜ 0.05).The 24 h systolic blood pressure variation (24 h SBPV) and night systolic blood pressure variation (nSBPV) were higher than those of non-plaque group (P ＜0.01).Multivariate regression analysis results showed that carotic artery plaque was associated positively with 24 h BPV and blood pressure variability coefficient of nighttime (P ＜ 0.05).Conclusions The elderly hypertensive patients with carotid artery plaque is associated positively with 24 h systolic blood pressure variability coefficient and blood pressure variability of nighttime.

Objective To study the brain protection of sequential double-sided antegrade cerebral perfusion to central nervous system in arotie arch surgery. Methods 24 patients received aortic arch replacement under deep hyperthermic circulatory arrest (DHCA) ,with fight-sided, and following double-sided, and left-sided,if necessary, antagrade cerebral perfnsion through right axillary arterial cannula or right femoral arterial eannula homeochronously. Post-operation recovery and the central nervous complications (CNC) were recorded and analyzed. Results 2 cases died, one of whom died of refractory low cardiac output syndrome and the other died of late massive gastrointestinal tract hemorrhage. No patient suffered severe CNC. Conclusion Sequential double-sided antegrade cerebral perfusion combined with DHCA can provide good brain protection in arotic arch replacement.

Objective: To explore the blood-saving effect of autologous platelet-rich plasma (PRP) back-transfusion in patients with Stanford type A aortic dissection surgery. Methods: A total of 59 consecutive patients who received Stanford type A aortic dissection surgery in our hospital from 2013-01 to 2015-10 were studied. The patients were at the age of (50±6) years with mean body weighting at (80±12) kg and were randomly divided into 2 groups: Traditional (T) group,n=31 and Autologous PRP back-transfusion (P) group,n=28. Blood levels of Hb, platelet counts, PT, APTT were measured at pre-induction of anesthesia (T1), before CPB (T2), prior ifnishing of CPB (T3) and at 1 h (T4), 24 h (T5), 48 h (T6) after the operation. The in-operative, 48 h post-operative volumes of allogeneic blood transfusion and the volume of chest tube drainage at 48h after operation were recorded; the complication occurrence at peri-operative period was recorded. Results: In P group, whole blood processing volume was (1269±197) ml, PRP volume was (753±78) ml, PRP separation time was (35±9) min and the separated platelets were about (22±3)% of total platelet counts. Compared with T group, P group had decreased Hb at T2 (131.0±15.0) g/L vs (101.0±10.0) g/L, decreased platelet counts at T3 (115.0±51.0)×109 /L vs (83.0±23.0)×109/L, while increased platelet counts at T4 (103.0±25.0)×109/L vs (151.0±27.0)×109/L, T5 (105.0±25.0)×109 /L vs (147.0±39.0)×109/L and T6 (101.0±26.0) ×109/L vs (149.0±35.0)×109/L, allP<0.05; P group presented reduced PT at T4 (17.6±2.1) s vs (14.1±1.1) s and T5 (17.6±2.7) s vs (13.5±0.8) s, allP<0.05. The in-operative transfusions of platelet, plasma, cold precipitation and post-operative transfusions of red blood cells, platelets, plasma, cold precipitation and the volume of chest tube drainage at 48h after operation were less in P group,P<0.05. Compared with T group, P group had the lower rates of acute post-operative lung injury (32.1% vs 19.4%), shorter mechanical ventilation time (69.1±5.9) h vs (43.1±1.5) h and ICU staying time (8.1±2.8) d vs (5.3±1.1) d, allP<0.05. Conclusion: Autologous PRP back-transfusion could reduce the post-operative bleeding and allogeneic blood transfusion for Stanford A aortic dissection surgery, it has obvious blood-saving effect.

Objective To explore the risk factors and optional treatment strategies for postoperative hypoxemia in patients undergoing acute Stanford A aortic dissection surgery.Methods From December 2012 to April 2014,108 patients received acute Stanford A aortic dissection surgery in Henan Provincial People' s Hospital.Of them,74 men vs.34 women,age (43.2 ± 10.1) years old,and weight (71.3 ± 18.4) kg.The operation was performed within 14 days since disease onset.All patients received surgery under deep hypothermic circulatory arrest(DHCA) and the nasal temperature goal was below 20 ℃ .Postoperative hypoxemia was defined as the arterial partial oxygen over inspired oxygen fraction(PaO2/FiO2) more than 200 after admission to ICU.Pulmonary protective ventilation management took place immediately after hypoxemia was diagnosed.Comparison analysis was performed between hypoxemia group and non-hypoxemia group in age,gender,body mass index (BMI),smoking history,duration of cardiopulmonary bypass(CPB),duration of DHCA,blood transfusion,length of mechanical ventilation,length of ICU stay and mortality.Results The incidence of postoperative hypoxemia was 40.7％ (44/108).There were no statistical differences in age,gender,hypertension,diabetes mellitus or COPD history.In the hypoxemia group,11 cases developed pulmonary infection,3 cases underwent tracheotomy and 10 cases died.In the non-hypoxemia group,4 patients died.Postoperative hypoxemia was significantly associated with more mortality,length of ventilation time,length of ICU stay and in hospital(P ＞ 0.05).Univariate analysis showed the associated factors were BMI,smoking history,preoperative hypoxemia,LVEF ＜ 0.45,operation time,aorta clamping time,DHCA time and blood transfusion.Multivariate analysis showed the independent predictive factors were preoperative hypoxemia,DHCA ＞40 min,blood transfusion ＞ 10 U and BMI ＞25 kg/ m2.Conclusion Obesity,massive blood transfusion,long DHCA time and preoperative hypoxemia are independent risk factors of postoperative hypoxemia in patients undergoing acute Stanford A aortic dissection surgery.Perioperative pulmonary protection should be paid more attention and reinforced.

Objective To investigate certain risk factors for postoperative atrial fibrillation (AF) in elderly patients with coronary heart disease after off-pump coronary artery bypass grafting (OPCAB)surgery in order to provide a basis for the prevention and treatment of AF after OPCAB.Methods A total of 139 elderly patients with coronary heart disease who had undergone OPCAB surgery in our hospital were collected as research subjects and divided into the AF group and the nonAF group according to the occurrence of AF after operation.The patients' general information and clinical data were retrospectively analyzed.Risk factors for AF after OPCAB surgery in elderly patients with coronary heart disease were investigated.Results The incidence of AF after OPCAB was 15.8％ in elderly patients with coronary heart disease.There were no statistical differences in gender,history of diabetes,history of myocardial infarction,preoperative β-blocker usage,number of coronary artery lesions,or operation time between the AF group and the non-AF group (P＞0.05).The percentage of patients who were of older age (t=9.960) or had a left ventricular ejection fraction ≥40％ (x2=4.942),a left atrial diameter ≥40 mm (x2 =4.491),a history of hypertension (x2 =12.357),dopamine medication after operation (x2 =8.511),or a bypass vessel count≥ 3 (x2 =5.385) was higher in the AF group than in the non-AF group (all P＜0.05).Logistic regression analysis showed that age,history of hypertension,dopamine medication after operation,left atrial diameter and bypass vessel count were the risk factors for AF after OPCAB surgery in elderly patients with coronary heart disease (OR 3.080,2.435,2.465,3.593,and 1.921,respectively,P＜0.05 for all).Conclusions The incidence of AF after OPCAB is high in elderly patients with coronary heart disease and is affected by many risk factors.These risk factors should be assessed before surgery so that appropriate prevention measures can be taken.