Objective To explore the influence of dexmedetomidine on wake-up test during spinal orthopaedic surgery. Methods All 80 patients taking spinal orthopaedic surgery were randomly divided into the trial group and the control group, with 40 cases in each group. The endotracheal intubation anesthesia was adopted in both groups with same anesthesia induction. Additionally, dexmedetomidine 0.8 μg/ (kg·h) was infused within 10 min in the trial group before anesthesia induction, and then another 0.5 μg/ (kg·h) was also infused from the intraoperation to suture of incision. For the control group, the same amount of normal saline was infused, and all the narcotics were stopped pumping 15 min before the wake-up test, but then were continued pumping after the wake-up test. Finally, the following indexes were analyzed: wake-up time, wake-up quality, hemodynamic changes at the time of 15 min before wake-up (T1), recovery of spontaneous breathing (T2), wake-up (T3) and 15 min after wake-up (T4), dosage of narcotics, and the incidence of adverse events. Results There was no significant difference in the operation time before wake-up between the two groups (P=0.07). For the trial group, the dosage of sevoflurane (P=0.03) and sufentanil (P=0.00) used before wake-up was significantly lower, the wake-up time (P=0.04) and bleeding amount during wake-up (P=0.00) were significantly less, the wake-up quality (P=0.03) was significantly higher, the blood pressure (P=0.00) and heart rate (P=0.00) when wake-up were significantly lower, and the incidence of adverse events (P=0.04) was significantly lower, compared with the control group. Conclusion Dexmedetomidine adopted in spinal orthopaedic surgery can significantly improve patient’s wake-up quality, shorten wake-up time, reduce bleeding amount when wake-up and adverse events after wake-up, and maintain the hemodynamic stability, so it has better protective effects.
PURPOSE:To investigate the relationship between the development of the diabetic retinopathy(DR)and the changes of ocular hemodynamics. METHODS:The hemodynamic parameters (Vmax,Vmin,RI)of central relinal artery(CRA )and central retinal vein(CRV)were measured both in the diabetes mellitus(DM) group(72 cases)and the control group(28 cases)with color Doppler flow imaging(Acuson-128XP/10). RESULT:The hemodynamic changes in CRA and CRV in the different stages of DR had their own characteristicS. The blood flow in CRA of the DM patients without DR was higher than that of the control (Plt;0.05). With tile deterioration of the retinopathy the blood flow in CRA decreased. The velocity of the blood flow in CRA of the proliferative DR group was less than that in the control ,DM without DR patients and background DR patients(Plt;0.05). The velocity of the flow in CRV of the DM patients was higher than that of control (Plt;0.001 )and exhibited its remarkable pulsative pattern. CONCLUSIONS:The changes of the hemodynamics in CRA.CRV was associated with the development of the diabetic retinopathy. （Chin J Ocul Fundus Dis,1997,13: 210-212 ）
Objective To study the influence of the pedicle length on the perforator flaps in hemodynamics. Methods Four mature swine (2 males, 2 females; weight, 23.0±2.0 kg) were applied to the experiment.Two transverse abdominal skin flaps, based on the superior epigastric pedicle orits rectus abdominal muscle perforators, were designed; each swine was used as its own control. At 2 hours and 1, 2, 3 weeks postoperatively, the skin paddle perfusion and the blood stream velocity in the superior epigastric artery were measured by the Laser Doppler Flowmeter and the Color Doppler Ultrasound, respectively. Flap survival percentages were calculated by the grid method at 1 week postoperatively. The swine were euthanatized, and they underwent angiography at 3 weeks postoperatively. Results At 2 hours and 1 week after operation, edema of the perforator flaps with the superior epigastric pedicle was more severe than that of the skin flaps with the rectus abdominal muscle perforator, and the skin perfusion had a statistical difference between the two kindsof flaps (Plt;0.05). The skin paddle viability and the skin perfusion had nostatistical difference after the first week postoperatively (Pgt;0.05). At 2hours and 1 week after operation, the blood stream velocity in the superior epigastric artery in the perforator flap with the superior abdominal artery pediclewas reduced, and there was a statistical difference between the two kinds of flaps (Plt;0.05); however, the velocity was almost the same after the first week postoperatively. Conclusion The excessively long pedicle of the perforator skin flap may have an unfavorable influence on the flap perfusion,especially during the first week after operation, because of the vascular compromise during the dissection of the long pedicle. The blood vessel anastomosis atthis level of the blood vessels may have no relationship with the perforator flap in hemodynamics. This study can also indicate that the ligation of the branches in the recipient vessels cannot make the perforator flaps overperfused.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation. MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope. ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups. ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.
Abstract: Objective To examine the cell viability and hemodynamic functions of the stented homograft valves preserved in liquid nitrogen. Methods Cell viability of the stented homograft valve preserved in liquid nitrogen after 3 months of preservation (experimental group，n=6) was examined using flow cytometer. Fresh homografts served as control group (n=6). We prepared three sorts of stented homograft valve(21#, 23#, 25#) preserved by liquid nitrogen. In vitro pulsatile flow tests were performed on valves of two groups. Effective opening area EOA),transvalve pressure gradient and regurgitation ratio were recorded at various flow volume, and compare with Perfect bioprosthetic valve. Results The results revealed that the death ratio of endothelial cell was 10.24%±1.71% in the experimental group, and 9.09%±2.72% in the control group (P=0.441). The death ratio of smooth muscle cell was 8.76%±1.82% in the experimental group, and 7.84%±0.59% (P=0.178) in the control group. The death ratio of total cell was 8.79%±1.44% in the experimental group, and 7.40%±0.49% in the control group (P=0.072). There were no significantly differences between two groups. The transvalve pressure gradient of two groups of valve depended on the flow volume, and increased with the flow volume increasing. The transvalve pressure gradient of the stented homograft valve was higher than that of Perfect valve. Regurgitation ratio of the stented homograft valve was bigger than Perfect valve’s. EOA had an increasing character when flow volume increased. EOA of the stented homograft valve was smaller than that of Perfect valve’s. Conclusion Liquid nitrogen can offer the benefit of cell viability of the stented homograft bioprosthetic valves. The stented homograft valve has salisfactory hemodynamic functions.
Objective To approach the effect of neck hyperextension position on hemodynamics of vertebral artery following thyroidectomy， and analyze the correlation between the change of hemodynamics and nausea and vomiting. Methods One hundred and fifty-eight patients with preparing for thyroidectomy （thyroidectomy group） and 89 patients with laparoscopic cholecystectomy （LC， LC group） were selected. The anesthesia method and the anesthesia drugs were the same in two groups. The indexes of hemodynamics of the bilateral vertebral artery at 6 h before and after thyroidectomy were measured. The difference of nausea and vomiting was observed and compared in two groups. Results The average blood flow velocity of the bilateral vertebral artery reduced and the blood flow decreased at 6 h after thyroidectomy as compared with at 6 h before thyroidectomy （P＜0.05）. The rates of nausea and vomiting of 0，2， 3， 4 times in the thyroidectomy group were significantly higher than those in the LC group （P＜0.05， P＜0.01）. The durations of nausea and vomiting of 1， 2， 3， 4 times in the thyroidectomy group were also significantly longer than those in the LC group （P＜0.01）. There was a positive correlation between the nausea and vomiting and the changes of blood flow velocity or blood flow （change of blood flow velocity：rs=0.697， P=0.03；change of blood flow：rs=0.897， P=0.01）. Conclusions There is a certain effect of the neck hyperextension position on hemodynamics of the bilatreal vertebral artery， and which might affect the nausea and vomiting following thyroidectomy.
Objective To investigate change of bispectral index(BIS) and hemodynamic index during induction and orotracheal intubation of sevoflurane anesthesia. Methods This study was a prospective before-after study in the same patients. A total of 30 ASA physical status I and II adult patients without airway abnormalities were enrolled to receive inhalation induction of anesthesia with 8% sevoflurane. Mean arterial pressure(MAP),heart rate(HR) and BIS were recorded before anesthesia(T1),when patients loss of consciousness(T2), before intubation (T3),at 1 min(T4) and 3 min(T5) after intubation. Results BIS at T1-T5 were 96.8±1.7,70.4±8.8,39.2±8.4,43.6±12.9 and 41.6±9.3 respectively, the measurements at T2-T5 were all markedly lower than at T1(Plt;0.05). HR at T3-T5 were all markedly higher than at T1(Plt;0.05). MAP at T2 and T3 were markedly lower than at T1, but at T4 was higher than at T1(Plt;0.05), and recovered to the level at T1 at T5(Pgt;0.05).BIS,HR and MAP at T4 were all significantly higher than T3(Plt;0.05). Conclusion Anesthesia induction with sevoflurane and small dose of succinylchoiline we used can provide adequate depth of general anesthesia,but can not prevent cardiovascular adverse reactions to intubation.
Objective To investigate the hemodynamic performance of valved bovine jugular vein conduits (BJVC) for right ventricular outflow tract reconstruction in canine model. Methods The BJVC that were treated with the glutaraldehyde were implanted between the pulmonary artery and right ventricle in seven young canines. Right ventricular and pulmonary artery pressures were measured directly before and after the implantation. Hemodynamic evaluations were carried out by echocardiography and cardiac catheterization after the implantation. Results Seven canines were survival one year after the implantation. The pulmonary artery pressures (including systolic pressure, diastolic pressure and mean pressure) had not significantly changed after reconstruction with the conduits. The right ventricular diastolic pressures had not increased after the reconstruction, but the right ventricular systolic pressure and mean pressure had increased. One year later, the echocardiography showed valve motion with no obvious thickening of the leaflets. No graft kinking or obvious regurgitation of the valve was observed. Cardiac catheterization and angiography showed that the pressure gradients between the right ventricle and the conduits varied from 3 to 19mmHg, the diastolic pressures in the conduits were higher than that of right ventricle((Plt;)0.01), and the conduits and pulmonary arteries had no obvious obstruction. Conclusion The glutaraldehyde-fixed bovine jugular vein conduit has good hemodynamic performance in the pulmonary circulation.
ObjectiveTo explore the effects of metoprolol on hemodynamics of early septic shock patients with myocardial injury. MethodsWe prospectively recruited 22 septic shock patients with myocardial injury, who were admitted to the ICU of Xiaolan Hospital during March 2014 and February 2015.The metoprolol was injected through central venous catheter to reduce heart rate by 20% from baseline and maintain for 6h.Hemodynamic and oxygen metabolic parameters were collected to establish database. ResultsHeart rate decreased significantly to (98±18), (95±16) and (92±18) beat/min respectively at 1h, 3h and 6h post-dosing, compared with (125±28) beat/min at pre-dosing (P < 0.05).Cardiac index decreased significantly to (3.2±1.5), (3.3±1.9) and (3.3±1.6) L·min-1·m-2 respectively at 1h, 3h and 6h post-dosing, compared with (3.9±2.5) L·min-1·m-2 at pre-dosing (P < 0.05).The mean blood pressure, central venous pressure, pulmonary artery wedge pressure, pulmonary vascular resistance index, systemic vascular resistance index and stroke volume index showed no significant changes between pre-dosing and post-dosing (all P > 0.05). Lactate concentration decreased significantly to (9.8±4.1) and (8.1±3.6)mmol/L respectively at 3h and 6h post-dosing, compared with (13.4±5.2)mmol/L at pre-dosing (all P < 0.05), but mixed venous oxygen saturation showed no significant changes (P > 0.05). ConclusionMetoprolol may reduce heart rate and cardiac output in septic shock patients with myocardial injury, without obvious adverse effects on circulatory function and systemic perfusion.
Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.