The hemodynamics changes of the common carotid arteries in 10 SD rats were measured with a color doppler flowmetry in an attempt to define the changes resulting from end-to-end anastomosis. The left common carotid arteries were divided and followed by end-to-end anastomosis. The systolic mean peak velocities in the left arteries were measured at the proximal, distal and anastomotic sites and in the right intact arteries as well at 6, 12, 24, 48, 72 and 120 hours after repair. The percentage of area reduction at anastomosis was calculated from these data. The results indicated that the systolic mean peak velocity at the anastomotic sites was significantly increased as compared to the velocity at the proximal, distal and contralateral sites (P lt; 0.05). The velocity at the distal sites was significantly lower than that from the proximal and contralateral sites (P lt; 0.05), the mean percentage of the reduction was 33.18% and 33.33%, respectively. From 6 hours to 120 hours after anastomosis of arteries there was various degree of narrowing at the site of anastomosis. The mean per cent of stenosis was 42.48%. It was concluded that from 6 to 120 hours after end-to-end anastomosis of the small arteries, the velocity at the anastomotic site was increased as compared to the velocities at pre- and post-anastomotic sites. The increase of velocity at the site of anatomosis was caused by stenosis at the anastomosis.
ObjectiveTo observe ocular ischemic appearance (OIA) associated with carotid artery stenosis and its effects on the hemodynamics of central retinal artery (CRA) and ophthalmic artery (OA). MethodsA total of 30 normal persons and 60 patients with carotid artery stenosis diagnosed by color Doppler flow imaging (CDFI) and digital subtraction angiography (DSA) were enrolled in this prospective study.Sixty patients were randomly divided into 2 groups:30 patients with the carotid artery stenosis degree < 60% and 30 cases with the carotid artery stenosis degree≥60%. Thirty normal persons were enrolled in the normal control group. All patients underwent a comprehensive eye examination to determine if OIA exists. The Doppler spectral patterns of CRA and OA were observed by CDFI. The peak systolic velocity (PSV), end diastolic velocity (EDV), blood vessel diameter (BVD) and resistance index (RI) of CRA and OA were measured. ResultsIn the group of the carotid artery stenosis degree≥60%, 24/30 patients (80.0%) had the ophthalmic symptoms and 9/30 patients (30.0%) had ophthalmic signs. In the group of the carotid artery stenosis degree < 60%, 9/30 patients (30.0%) had the ophthalmic symptoms and 3/30 patients (10.0%) had ophthalmic signs. For patients with≥60% stenosis, CDFI revealed a bread-like waveform of CRA, and single peak of OA instead of the typical 3-peak/2-notch waveform. For patients with < 60% stenosis, CDFI revealed a normal pattern of CRA and OA (3-peak/2-notch). The PSV(t=5.255, P=0.007) and EDV(t=4.949, P=0.005) of CRA in the stenosis≥60% group were statistically decreased compared to the normal control group, but the BVD(t=0.457, P > 0.05)and RI(t=0.213, P > 0.05)were normal. The PSV, EDV, BVD and RI of CRA in the stenosis < 60% group were normal(P > 0.05). The PSV(t=4.457, P=0.010)and EDV(t=4.588, P=0.009)of CRA in the stenosis≥60% group were statistically decreased compared to the stenosis < 60% group, but the BVD and RI were the same between these 2 groups. ConclusionPatients with carotid stenosis≥60% had a higher OIA incidence, reduced PSV, EDV of their CRA, while had no significant changes of OA hemodynamics.
ObjectiveTo investigate the effects of prone position ventilation on oxygenation,hemodynamics and airway drainage in patients with severe aspiration pneumonia with acute respiratory distress syndrome (ARDS). Methods28 patients with severe aspiration pneumonia with ARDS admitted between January 2010 and June 2012 were recruited in the study. They were ventilated in prone position with sedation and paralysis. Mean blood pressure (MAP),heart rate (HR),central venous pressure (CVP),pulse oxygen saturation (SpO2),arterial oxygen tension (PaO2),carbon dioxide partial pressure (PaCO2),oxygenation index (PaO2/FiO2) and sputum drainage were recorded in the time points of initial supine position,prone position 1h,prone position 2h,and return to supine position 2h. ResultsCompared with the time point of initial supine position,PaO2 and PaO2/FiO2 increased significantly after 1 and 2 hours in prone position [PaO2:(85±12)mm Hg and (97±10)mm Hg vs. (65±11)mm Hg;PaO2/FiO2:(150±37)mm Hg and (158±50)mm Hg vs. (130±28)mm Hg;all P<0.05]. The effects of oxygenation improving were persistent 2h after return to supine position [PaO2:(87±11)mm Hg;PaO2/FiO2:(150±52)mm Hg,P<0.05]. There was no significant difference in MAP,HR,CVP,or SpO2 during the study. Airway sputum drainage was significantly increased 2h after in prone position compared with that in initial supine position [(15.3±2.0)mL vs. (8.1±1.1)mL,P<0.05]. Airway sputum drainage had no significant difference among 1h afer prone position,2h after return to supine position and the initial supine position [(9.1±1.0)mL and (8.3±1.2) mL vs. (8.1±1.1)mL,P>0.05]. ConclusionProne position ventilation can improve the oxygenation in patients with severe aspiration pneumonia with ARDS,and the effects of oxygenation improvement can be persistent till 2h after return to supine position. Prone position ventilation can improve sputum drainage without significant influence on hemodynamics,thus can be used as an adjuvant treatment for severe aspiration pneumonia with ARDS. The duration of prone position ventilation needs to be prolonged for patients with much airway secretion.
Objective To observe the ocular hemodynamic changes and flow direction of ophthalmic artery of patients with severe internal carotid stenosis (ICAS) and investigate the relationship between flow direction of ophthalmic artery and degree of stenosis. Methods Forty eyes of 40 patients with unilateral highgrade ICAS (29 eyes, 72.5%) and internal carotid artery occlusion (11 eyes, 27.5%) diagnosed by color Doppler flow imaging (CDFI) were enrolled in this study. There were 14 eyes (35.0%) with obvious ocular signs of ischemia, 26 eyes (65.0%) without obvious signs of ocular ischemia. The peak systolic velocity (PSV) of central retinal artery (CRA) was measured. The flow direction of the ophthalmic artery was observed by digital subtraction angiography (DSA). The PSV of CRA in eyes with different flow directions in the ophthalmic artery was comparatively analyzed. The relationship between flow direction of the ophthalmic artery and degree of stenosis was also analyzed. Results The PSV of CRA in ICAS eyes was (6.59plusmn;1.49) cm/s, which was decreased compared to fellow eye (8.95plusmn;1.35) cm/s, the difference was statistically significant (t=-7.24,P＜0.01). The PSV of CRA in eyes with signs of obvious ocular ischemia was (5.84plusmn;1.42) cm/s, which was decreased compared to eyes without signs of obvious ocular ischemia (7.00plusmn;1.39) cm/s, the difference was statistically significant (t=-2.49,P＜0.05). There were 15 eyes (37.5%) with retrograde flow in the ophthalmic artery, 25 eyes (62.5%) with forward flow of ophthalmic artery. The PSV of CRA in eyes with retrograde flow and forward flow of ophthalmic artery were (6.96plusmn;2.09), (7.01plusmn;1.42) cm/s, the difference was not statistically significant (t=-0.09，P＞0.05). Among 15 eyes with retrograde flow of ophthalmic artery, there were five eyes (33.3%) with unilateral high-grade ICAS, 10 eyes (66.7%) with internal carotid artery occlusion. The incidence rate of retrograde flow in the ophthalmic artery in eyes with internal carotid artery occlusion was higher than that in eyes with unilateral high-grade ICAS (P＜0.01). Conclusions The PSV of CRA in eyes with severe ICAS decreased compared to fellow eyes. The PSV of CRA in eyes with signs of obvious ocular ischemia also decreased compared to eyes without obvious signs of ocular ischemia. With the increase of the degree of the internal carotid artery stenosis, the incidence of retrograde flow of ophthalmic artery increased.
ObjectiveTo evaluate the effect of positive end-expiratory pressure (PEEP) on respiratory function and hemodynamics in acute lung injury (ALI) with intra-abdominal hypertension (IAH). MethodsSix pigs were anesthetized and received mechanical ventilation (MV). Volume controlled ventilation was set with tidal volumn(VT) of 8 mL/kg,respiratory rate(RR) of 16 bpm,inspired oxygen concentration (FiO2) of 0.40,and PEEP of 5 cm H2O. ALI was induced by repeated lung lavage with diluted hydrochloric acid (pH<2.5) until PaO2/FiO2 declined to 150 mm Hg or less to established ALI model. Intra-abdominal hypertension was induced by an nitrogen inflator to reach intra-abdominal pressure of 20 mm Hg. Respiratory parameters and hemodynamics were continuously recorded at different PEEP levels(5,10,15,and 20 cm H2O). Every level was maintained for one hour. ResultsPaO2/FiO2 in PEEP5,10,15 and 20 were 90±11,102±10,172±23 and 200±34 mm Hg respectively. PaO2/FiO2 in PEEP15 and 20 were significantly higher than those in PEEP5 and 10 (P<0.05). Chest wall compliance (Ccw) in PEEP5,15 and 20 were 26±3,76±15 and 85±14 mL/cm H2O respectively. Ccw in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in lung compliance (CL) in different PEEP levels (P>0.05). Plateau pressure(Pplat) in PEEP5,10,15 and 20 were 30±3,31±2,36±2 and 38±4 cm H2O respectively. Pplat in PEEP15 and 20 were significantly higher than those in PEEP5 and 10 (P<0.05). There was no significant difference in Pplat between PEEP15 and 20 (P>0.05). Heart rate (HR) in PEEP5,15 and 20 were 113±17,147±30,and 160±30 beat/min respectively. HR in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in HR between PEEP15 and 20 (P>0.05).Cardiac index (CI) in PEEP5 and 20 were 4.5±0.6 and 3.5±0.6 L·min-1·m-2 respectively. CI in PEEP20 was significantly lower than that in PEEP5 (P<0.05). There was no significant difference in CI in PEEP5,10 or 15(P>0.05). Central venous pressure(CVP) in PEEP5,15 and 20 were 12±2,17±2,and 18±3 mm Hg respectively. CVP in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in CVP between PEEP15 and 20 (P>0.05). There were no significant differences in MAP,SVRI,ITBVI,GEDI,PVPI,or EVLWI between different PEEP levels. ConclusionConcomitant ALI and IAH can induce great impairments in respiratory physiology. When PEEP is gradually increased,oxygenation and the respiratory function are improved without significant secondary hemodynamic disturbances.
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.
By using noninvasive venous plethysmography, venography and skin morphology, 44 patients (57 limbs) with chronic venous insufficiency (CVI) in lower extremity were studied , and compared with 12 normal subjects (24 limbs). The results showed that dermal nutrient disturbance caused by deep venous insufficiency accounted for 68%, and followed by perforating venous insufficiency was 44%. Furthermore compared venous refill time (VRT), segmented venous capacitancy (SVC) and maximum venous outflow (MVO) of dermal nutrient disturbance with those of exterior normal skin and normal subjects; and compared VRT, SVC, MVO of deep vein 3-4 stage reflux with those of 1-2 stage reflux and normal subjects,the differences were very significant (Ｐ＜0.05). Compared the VRT of perforating incompetence with that of competence (Ｐ＜0.01). Dermal pathology and ultramicrostructure showed that leucocytes trapping in capillary was a cause of microangiopathy. These results suggest that deep vein 3-4 stage reflux followed by calf perforating insufficiency was a main cause for dermal nutrient disturbance; lower extremity VRT reduced obviously and SVC increased significantly were hemodynamic character, leucocytes trapping in capillary was pathology basis of skin damage.
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.
This study was performed on canine femoral veins which were interpositionally implanted into the femoral arteries and the investigation was in terms of zero-stress state, compliance and hemodynamic assessment. The results revealed that the vein grafts had the similar characteristics of compliance with the normal veins. Using Doppler ultrasonography to monitor the blood flow velocity through the vein grafts, the hemodynamic parameters such as pulsatility index (PI) and blood flow volume were evaluated consecutively within one month after the operations .No significant differences were found between these parameters at different time points. It was suggested that autogenous vein graft had an adaptive course when operating in an arterial hemodynamic circumstances and It’s mechanical changes did not bear upon the hemodynamics through the vein graft.