west china medical publishers
Keyword
  • Title
  • Author
  • Keyword
  • Abstract
Advance search
Advance search

Search

find Keyword "Hemodynamics" 39 results
  • Impact of Splenectomy Plus Pericardial Devascularization on Liver Hemodynamics and Liver Function for Liver Cirrhosis Patients with Portal Hypertension

    ObjectiveTo investigate impact of splenectomy plus pericardial devascularization on liver hemodynamics and liver function for liver cirrhosis patients with portal hypertension. MethodsThe internal diameter, maximum velocity, minimum velocity, mean velocity, and flow volume of portal vein and hepatic artery of 42 cases of liver cirrhosis with portal hypertension were measured by Doppler ultrasonic instrument on day 1 before operation and on day 7 after operation. The free portal pressures at different phases (after open abdomen, after splenic artery ligation, after splenectomy, and after devasculanrization) were read from the disposable pressure sensor. Twenty-four healthy people through physical examination were selected as control. Results① The free portal pressure of liver cirrhosis patients with portal hypertension was decreased from (29.12±1.40) mm Hg after open abdomen to (22.71±1.21) mm Hg after splenic artery ligation, and further decreased to (21.32±1.12) mm Hg after splenectomy, but increased to (22.42±1.15) mm Hg after devasculanrization, the difference was statisticly different (all P < 0.01). ② Compared with the healthy people, for the liver cirrhosis patients with portal hypertension, the internal diameter, maximum velocity, minimum velocity, and flow volume of portal vein were significantly enlarged (all P < 0.01), which of hepatic artery were significantly reduced (all P < 0.01) on day 1 before operation; On day 7 after operation, the internal diameter of portal vein was significantly reduced (P < 0.01), the maximum velocity, minimum velocity, and mean velocity of portal vein were significantly enlarged (all P < 0.01), but the internal diameter of hepatic artery was significantly reduced (P < 0.01), the maximum velocity, minimum velocity, mean velocity, and flow volume of hepatic artery were significantly enlarged (all P < 0.01). For the liver cirrhosis patients with portal hypertension, compared with the values on day 1 before operation, the internal diameter and the flow volume of portal vein were significantly reduced (all P < 0.01) on day 7 after operation; the internal diameter, maximum velocity, minimum velocity, mean velocity, and flow volume of hepatic artery were significantly enlarged (all P < 0.01) on day 7 after operation. ③ The Child-Pugh classification of liver function between before and after surgery had no significant difference (χ2=1.050, P > 0.05). ④ No death and no hepatic encephalopathy occurred, no thrombosis of splenic vein or portal vein was observed on day 7 after surgery. Conclusionsplenectomy plus pericardial devascularization could decrease portal vein pressure and reduce blood flow of portal vein, while increase blood flow of hepatic artery, it doesn't affect liver function.

    Release date:2016-10-02 04:54 Export PDF Favorites Scan
  • MECHANICAL AND HEMODYNAMIC CHANGES IN AUTOGENOUS VEIN GRAFTS

    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.

    Release date:2016-09-01 11:33 Export PDF Favorites Scan
  • A STUDY ON HEMODYNAMIC AND MORPHOLOGIC CHANGES OF DERMAL NUTRIENT DISTURBANCE IN VENOUS DISEASE

    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.

    Release date:2016-08-29 03:18 Export PDF Favorites Scan
  • Ocular ischemic appearance associated with different carotid artery stenosis degree and its effects on hemodynamics of eye and central retinal artery

    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.

    Release date: Export PDF Favorites Scan
  • INFLUENCE OF PEDICLE LENGTH ON PERFORATOR FLAP IN HEMODYNAMICS

    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.

    Release date:2016-09-01 09:22 Export PDF Favorites Scan
  • Ocular hemodynamic changes and flow direction of the ophthalmic artery and its relationship with degree of stenosis in patients with severe internal carotid stenosis

    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 highgrade 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.

    Release date:2016-09-02 05:22 Export PDF Favorites Scan
  • THE HEMODYNAMIC CHANGES AFTER END-TO-END ANASTOMOSIS OF THE SMALL ARTERIES IN RATS

    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.

    Release date:2016-09-01 11:07 Export PDF Favorites Scan
  • Change of Bispectral Index and Hemodynamic Index During Induction and Orotracheal Intubation of Sevoflurane Anesthesia

    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.

    Release date:2016-08-25 03:35 Export PDF Favorites Scan
  • Neurofeedback technology based on functional near infrared spectroscopy imaging and its applications

    Neurofeedback (NF) technology based on electroencephalogram (EEG) data or functional magnetic resonance imaging (fMRI) has been widely studied and applied. In contrast, functional near infrared spectroscopy (fNIRS) has become a new technique in NF research in recent years. fNIRS is a neuroimaging technology based on hemodynamics, which has the advantages of low cost, good portability and high spatial resolution, and is more suitable for use in natural environments. At present, there is a lack of comprehensive review on fNIRS-NF technology (fNIRS-NF) in China. In order to provide a reference for the research of fNIRS-NF technology, this paper first describes the principle, key technologies and applications of fNIRS-NF, and focuses on the application of fNIRS-NF. Finally, the future development trend of fNIRS-NF is prospected and summarized. In conclusion, this paper summarizes fNIRS-NF technology and its application, and concludes that fNIRS-NF technology has potential practicability in neurological diseases and related fields. fNIRS can be used as a good method for NF training. This paper is expected to provide reference information for the development of fNIRS-NF technology.

    Release date:2022-12-28 01:34 Export PDF Favorites Scan
  • Effect of Prone Position Ventilation on Hemodynamics in Patients with Interstitial Lung Disease Concurrent with Acute Respiratory Distress Syndrome

    Objective To investigate the effect of prone position ventilation (PPV) on hemodynamics in patients with interstitial lung disease (ILD) concurrent with acute respiratory distress syndrome (ARDS) or not. Methods Severe ARDS patients received PPV treatment in intensive care unit from 2013 to 2015 were retrospectively analyzed. Pulse index continuous cardiac output (PiCCO) monitoring indices were compared 2h before PPV (PPV-2), in-PPV (PPVmean) and 2h after turn back to supine position (PPV+2), including mean arterial pressure (MAP), cardiac index (CI), intrathoracic blood volume index (ITBVI), etc. Heart function, liver function, renal function, coagulative function were compared before and after all the PPV treatment. Results Thirty-six severe pulmonary ARDS patients were recruited. Norepinephrine (NE) dose was (0.14±0.10) μg·kg-1·min-1 and lactate concentration was (1.70±0.57) mmol/L before PPV. CI in all the patients was increased [(4.06±0.95) L·min-1·m-2 vs. (3.98±1.05) L·min-1·m-2, P > 0.05) and central venous oxygen saturation, ITBVI [(76.94±8.94)% vs. (70.67±8.23)%, (982.17±245.87) mL/m2 vs. (912.97±177.65) mL/m2, P < 0.05)] were significantly increased compared with PPV-2, while heart rate (HR), MAP, urine volume were decreased (P > 0.05). The patients were divided into an ILD group (n=17) andanon-ILD group (n=19),and no significant differences were found in baseline data between two groups. Compared with PPV-2, MAP was significant decreased at PPV+2 [(85.44±10.84) mm Hg vs. (89.21±10.92) mm Hg, P < 0.05) in the ILD group. Compared with PPVmean, CI was obviously declined at PPV+2 in the ILD group. Activated partial thromboplastin time was increased [(67.04±97.52)s vs. (41.24±8.72) s, P < 0.05] and BUN was higher [(10.64±4.95) μmol/L vs. (8.18±3.88) μmol/L, P < 0.05] in the ILD group, while no significant difference was found in the non-ILD group. Conclusion PPV will not affect cardiac output in severe ARDS patients with ILD. It can increase venous return and improve tissue perfusion, but the perfusion of the abdomen organ need to be monitored cautiously.

    Release date:2016-10-02 04:56 Export PDF Favorites Scan
4 pages Previous 1 2 3 4 Next

Format

Content