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 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 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.
Objective To analyze the effect of monitoring and modulating the portal vein pressure and blood flow during living donor liver transplantation （LDLT） on preventing small-for-size-syndrome (SFSS). Methods Data of forty-four LDLT recipients between Oct.2007 and Oct.2008 were reviewed. Actual graft-to-recipient weight ratio（GRWR）, portal vein flow and pressure during operation and syndrome of SFSS after operation were recorded. The patients received splenectomy or splenic artery ligation according to actual GRWR, portal vein flow and pressure and WBC. Relationships between patients’ GRWR, portal vein flow, portal vein pressure and occurrence of SFSS were analyzed. Results Six patients received splenectomy and 7 patients received splenic artery ligation to decrease the portal vein flow and pressure during the operation. The portal vein flow and pressure decreased after splenectomy （Plt;0.05）. The portal vein pressure decreased （Plt;0.05） and the portal vein flow had no significant change after splenic artery ligation （P＞0.05）. No SFSS occurred after operation. Conclusion Modulation of portal vein flow and pressure by splenectomy or splenic artery ligation during LDLT operation can decrease the portal vein flow and pressure, and which can prevent the incidence of SFSS.
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.
fter fracture of femoral neck , the head is often encountered ayascular necrosis. It was not clearwhether the causes of the necrosis was due to injury of the artery or stagnation of venous return orboth. We had observed the hmeodynamics of the blood circulation of both fermoral head of both sides in 27 cases of subcapital fracture by E. C. T. (Emission Computerized Tomography). The resultsshowed that either old, fresh, or heal fractures showed stagnation of venous return. There wasoblite...
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.
Objective To investigate whether pulse pressure variation( ΔPP) reflect the effects of PEEP and fluid resuscitation ( FR) on hemodynamic effects. Methods Twenty critical patients with acute lung injury was ventilated with volume control ( VT =8 mL/kg, Ti/Te = 1∶2) , and PaCO2 was kept at 35 to 45 mm Hg. PEEP was setted as 5 cm H2O and 15 cmH2O in randomized order. Hemodynamic parameters including cardiac index, pulse pressure, central venous pressure, etc. were monitered by PiCCO system.Measurements were performed after the application of 5 cmH2O PEEP ( PEEP5 group) and 15 cm H2OPEEP ( PEEP15 group) respectively. When the PEEP-induced decrease in cardiac index ( CI) was gt; 10% ,measurements were also performed after fluid resuscitation. Results Compared with PEEP5 group, CI was decreased significantly in PEEP15 group( P lt;0. 05) , and ΔPP was increased significantly( P lt; 0. 05) . In 14 patients whose PEEP-induced decrease in CI was gt; 10% , fluid resuscitation increased CI from ( 3. 01 ±0. 57) L·min - 1·m- 2 to ( 3. 62 ±0. 68) L·min- 1 ·m- 2 ( P lt;0. 01) , and decreased ΔPP from ( 17 ±3) % to ( 10 ±2) % ( P lt;0. 01) . PEEP15 -induced decrease in CI was correlated negatively with ΔPP on PEEP5 ( r= - 0.91, P lt;0. 01) and with the PEEP15 -induced increase in ΔPP ( r = - 0. 79, P lt;0. 01) . FR-induced changes in CI correlated with ΔPP before FR ( r =0. 96, P lt; 0. 01) and with the FR-induced decrease in ΔPP ( r= - 0. 95, P lt; 0. 01) . Conclusions In ventilated patients with ALI, ΔPP may be a simple anduseful parameter in predicting and assessing the hemodynamic effects of PEEP and FR.
Objective To observe the effect of lowering intraocular pressure(IOP) treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION). Methods A total of 68 patients with NAION (68 eyes) were enrolled in this study. The patients were randomly divided into treatment group (38 eyes of 38 patients) and control group (30 eyes of 30 patients). All the patients were received methylprednisolone pulse therapy (200 mg, three days), vasodilator therapy with intravenous infusion of Xueshuantong solution (300 mg), optic nerve nutritional therapy with mouse nerve growth factor (30 mu;g) and acupoint injection in temporal with compound anisodine (2 ml). The total course was 10 days. The patients of treatment group received IOP lowering treatment to reduce the IOP to ge;8 mm Hg (1 mm Hg=0.133 kPa) or in a 30% reduction. The patients of control group received no IOP lowering treatment. The peak systolic velocity (PSV), pulsatility index (PI) and resistance index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and after treatment were comparatively analyzed by color doppler flow imaging. Results The differences of PSV (t=1.023, 1.145, 0.569), PI (t=0.679, 0.956, 1.634) and RI (t=0.816, 1.657, 0.998) of OA, CRA and PCA before treatment in treatment group and control group were not statistically significant (P＞0.05). Compared with before treatment, PSV (t=3.150, 7.650, 3.520) and PI (t=2.420, 5.430, 7.650) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (t=5.320, 9.640, 18.360;P＜0.05) after treatment in treatment group. In control group, the differences of PSV (t=2.090, -2.550, -2.100) and PI (t=-2.310, -2.230, -4.490) of OA, CRA and PCA between before and after treatment were not statistically significant (P＞0.05); but the differences of RI of OA, CRA and PCA between before and after treatment was statistically significant (t=2.970, 2.160, 2.690;P＜0.05). Compared with control group, PSV (t=2.632, 2.135, 5.364) and PI (t=3.251, 2.432, 4.243) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (t=3.664, 2.938, 4.324;P＜0.05) after treatment in treatment group. Conclusion Lowering intraocular pressure treatment can improve the ocular hemodynamics in NAION patients.