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Objective To observe any changes in spinal cord hemodynamics after spinal cord injury and to investigate their mechanism. Methods Twenty female Sprague-Dawley rats were divided into a control group and a moderate injury group,10 rats in each group.A rat model of spinal cord injury caused by moderate compression was established using Nystrom's method.Changes in the velocity and volume of blood flow and in the diameters of vessels of the spinal cord were monitored for 6 hours using laser speckle imaging. Results No changes in the velocity or volume of blood flow or in the diameter of vessels were observed in the control group,but all of these indices diminished significantly in the injury group. Conclusions Laser speckle imaging can be used to monitor changes in spinal cord hemodynamics.Such changes after acute spinal cord injury indicate progressive post-injury ischemia.The occlusion of veins may be an important contributor to post-injury ischemia.
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Objective To investigate the combination of color Doppler flow imaging (CDFI) and transcranial Doppler (TCD) in the assessment of the hemodynamic changes of vertebral artery occlusion disease and their clinical value. Methods A total of 101 patients with vertebral artery occlusion detected by the combination of CDFI and TCD and confirmed by DSA were enrolled from January 2005 to January 2009. Taking the result of digital subtraction angiography (DSA) as a golden standard, The differences between the different types of the side of vertebral artery occlusion and contralateral vertebral artery on the extra- and intracranial segments were compared and analyzed in peak systolic velocity (PSV), end diastolic velocity (EDV), resistive indices (RI), pulsatility index (PI), spectrum morphology, and hemodynamics. Results No blood flow signals were detected by CDFI and TCD in patients of complete occlusion of the vertebral artery; the weak blood flow signals were detected by CDFI in patients of the occlusion in the intracranial segment of the vertebral artery. 3he blood flow signals after the establishment of collateral circulation in patients of the segmental occlusion were detected in the extraeranial segment or intraeranial segment of the vertebral artery. The PSV on the occluded sides of the extraeranial segments were decreased more significantly than that on the unoccluded sides (27.39 ± 12.44 cm/s vs. 62.61 ± 13.22 cm/s, P = 0.000); RI was significantly higher than the unoccluded sides (0. 99 ± 0. 21 vs. 0. 62 ± 0.07, P = 0. 000). When a vertebral artery had the segmental occlusion and the collateral circulation was established, the PSV, EDV, and PI of the intracranial segment of the vertebral artery on the occluded sides were decreased more significantly than those on the unoccluded sides, PSV were 37. 81 ± 12.28 cm/s and 73.17±30. 99 cm/s, respectively (P =0. 000), EDV were 17.58 ± 7.10 cm/s and 29.31 ± 12.94 cm/s, respectively (P = 0. 000), PI were 0.84 ± 0.22 and 1.01 ±0. 18, respectively (P=0. 000). The compard DSA showed that the sites of vertebral artery occlusion were different, There was significant difference in the Doppler flow velocity spectrum between the CDFI and TCD. Conclusions PSV, EDV, RI, and PI are the hemodynamic parameters of accurately assessing vertebral artery occlusion, and the combination of CDFI and TCD has significant value for the hemodynamie changes of different types of vertebral artery occlusion and the clinical comprehensive assessment.
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Objective To investigate whether pulse pressure variation (△PP) 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 cm H2O 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 cm H2O PEEP (PEEPs group)and 15 cm H2O PEEP (PEEP15 group) respectively.When the PEEP-induced decrease in cardiac index (CI) was > 10%, measurements were also performed after fluid resuscitation.Results Compared with PEEPs group, CI was decreased significantly in PEEP15 group(P < 0.05), and APP was increased significantly (P < 0.05).In 14 patients whose PEEP-induced decrease in CI was > 10%, fluid resuscitation increased CI from (3.01±0.57)L · min-1· m-1to (3.62±0.68)L · min-1 · m-2(P<0.01),and decreased △PP from (17±3)% to (10±2) % (P < 0.01).PEEP15-induced decrease in CI was correlated negatively with APP on PEEP5 (r =-0.91,P < 0.01) and with the PEEP15-induced increase in △PP (r =-0.79, P < 0.01).FR-induced changes in CI correlated with APP before FR (r = 0.96, P < 0.01) and with the FR-induced decrease in APP (r =-0.95, P < 0.01).Conclusions In ventilated patients with ALI, △PP may be a simple and useful parameter in predicting and assessing the hemodynamic effects of PEEP and FR.
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Objective To investigate the relationship between refractory hypertension and renal hemodynamics in end stage renal diseases (ESRD) patients.Methods ESRD patients were classified into:patients with refractory hypertension (group A) and patients with normal blood pressure(group B).Renal hemodynamic indices were ex- amined by duplex ultrasonography.Fasting serum lipid (TC,TG,HDL-C,LDL-C,Lp(a),ox-LDL) and serum parathyroid hormane (PTH) were determined in all patients.Results Significant differences were found in renal hemodynamic indices such as peak systolic velocity (PSV),mean flow velocity (MV),pulsatility index (PI),renal- aortic ratio (RAR) and in clinical index such as Lp(a) and ox-LDL between the two group.Refractory hyperten- sion patients had lower renal hemodynamic indices and higher Lp(a) and ox-LDL levels than in patients with con- trolled BP.Logistic regression analysis revealed that refractory hypertension was related with PSV,EDV,Pl and RAR,but not relevant with sex,age,dialysis time,hematocrit,BUN,creatinine,TC,TG,HDL-C,LDL-C, PTH,MV and RI.Conclusion Atherosclerotic renal artery stenosis and severe disorder in renal hemodynamics is likely the cause for refractory hypertention in ESRD patients.The rise of serum Lp(a) and ox-LDL might acceler- ate renal artery atherosclerosis.
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This review summarized the current studies about the abnormality of blood cells morphology,transmembrane transport and membrane receptor and the change of Hemodynamies in essential hypertention.It suggests that these alternations play an important role in the pathogenesis of hypertention.
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Obiective: To verify the effects of aminoguanidine on hemodynamics in sepsis.Method:Experiments were conducted in five groups of anesthetized dogs (each group n=8).In group 1,lipopolysaccharide (LPS)was injected intravenously, Group 2 received both LPS and L-arginine (300mg/kg)intravenously. Group 3 received both LPS and N-nitro-Larginine (L-NNA,20mg/kg) intravenously.Group 4 received both LPS and aminoguanidine (30mg/kg) intravenously. Group 5 received only saline. Hemodynamic and oxygenational data were measured or calculated. Extravascular lung water (EVLW)was measured. Result:L-arginine increased CI and decreased PVRI,while treatment with aminoguanidine without significant increased the BP,SVRI and PVRI.But all of untoward hemodynamic effcts of LPS were exacerbated by the addition of L-NNA,as DO_2 was significantly decreased by L-NNA,Therefore,though O_2ER was also increase (insufficiently),VO_2 was still decreased significantly.EVLW was markedly increased by LNNA. Conclusion:The No-selective inhibition with adiministration of aminoguanidine may have considerable value in the therapy of endotoxin shock.
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Objective To investigate the effects of transection of cervical sympathetic trunk (TCST) on the blood flow of uterine artery (BFUA) and plasma concentrations of norepinephrine (NE) and nitric oxide (NO) in rats with pregnancy hypertension (PIH) . Methods Forty pregnant Wistar rats weighing 240-270 g were randomly divided into 5 groups with 8 animals in each group: control group( group C) , L-NAME induced hypertension groupl and 2 (group Bl, B2); TCST group and sham operation group. In control group no hypertension was induced. In group Bl and B2 hypertension was induced with L-NAME 12.5 mg.100-1 or 6.25 mg. 100-1 injected subcutaneously from 14 th to 20 th day of gestation. In TCST group TCST was performed on the 14th day of gestation and hypertension was induced as in group B1. In sham operation group cervical sympathetic trunk was exposed but not transected on the 14 th day of gestation and hypertension was induced as in group Bl. BFUA was measured and blood samples were taken from abdominal aorta for determination of plasma NE and NO concentrations on the 21 st day of gestation. Results (1) The mean BFUA during systole and systole + diastole was significantly lower in group Bl and B2 than that in group C ( P 0.05). (2) The plasma NE levels in group Bl and B2 were significantly higher than in that in group C (P