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.
ObjectivesTo systematically review the efficacy of lidocaine injected prior to tracheal extubation in preventing hemodynamic responses to tracheal extubation in general anesthesia.MethodsPubMed, Ovid, Web of Science, EMbase, The Cochrane Library, CBM, CNKI, VIP and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) on the efficacy of lidocaine administrated prior to extubation in preventing hemodynamic responses to tracheal extubation in patients undergoing general anesthesia from inception to October, 2018. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 and Stata 13.0 software.ResultsA total of 10 RCTs involving 525 patients were included. The results of meta-analysis showed that: compared with control group, lidocaine could reduce mean arterial pressure in 5 min after extubation (MD=–5.10, 95%CI –9.41 to –0.79, P=0.02), weaken the increase in systolic blood pressure caused by extubation from the moment before extubation to 5 minutes after extubation (before extubation: MD=–7.22, 95%CI –10.34 to –4.11, P<0.000 01; at extubation: MD=–14.02, 95%CI –19.42 to –8.62, P<0.000 01; 1 minutes after extubation: MD=–15.82, 95%CI –22.20 to –9.45, P<0.000 01; 3 minutes after extubation: MD=–12.55, 95%CI –20.36 to –4.74, P=0.002; and 5 minutes after extubation: MD=–12.05, 95%CI –20.35 to –3.74, P=0.004), and weakened extubation-induced increase in diastolic blood pressure at extubation (MD=–9.71, 95%CI –16.57 to –2.86, P=0.005). In addition, lidocaine inhibited heart rate in all time points except the moment of before and at 10 minutes after extubation.ConclusionsCurrent evidence shows that lidocaine can inhibit the increase in blood pressure and heart rate caused by extubation at certain times. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusions.
To investigate the biomechanical effects of direct ventricular assistance and explore the optimal loading mode, this study established a left ventricular model of heart failure patients based on the finite element method. It proposed a loading mode that maintains peak pressure compression, and compared it with the traditional sinusoidal loading mode from both hemodynamic and biomechanical perspectives. The results showed that both modes significantly improved hemodynamic parameters, with ejection fraction increased from a baseline of 29.33% to 37.32% and 37.77%, respectively, while peak pressure, stroke volume, and stroke work parameters also increased. Additionally, both modes showed improvements in stress concentration and excessive fiber strain. Moreover, considering the phase error of the assist device's working cycle, the proposed assist mode in this study was less affected. Therefore, this research may provide theoretical support for the design and optimization of direct ventricular assist devices.
Objective To explore the hemodynamic monitoring value of pulse-indicated continuous cardiac output( PiCCO) during lung transplantation. Methods Twenty patients with end-stage lung disease undergone lung transplantation were enrolled. Hemodynamic states were monitored by PiCCO and Swan-Ganz standard thermodilution pulmonary artery catheter( PAC) simultaneously at six stages throughout the study. Changes in the variables were calculated by subtracting the first fromthe second measurement( Δ1 ) and so on ( Δ1 to Δ5 ) . Results The linear correlation between intra-thoracic blood volume index( ITBVI) and stroke volume index( SVIpa) was significant ( r = 0. 654, P lt; 0. 05) , whereas pulmonary artery wedge pressure ( PAWP) poorly correlated with SVIpa( P gt; 0. 05) . Changes in ITBVI correlated with changes in SVIpa ( Δ1 , r =0. 621; Δ2 , r = 0. 784; Δ3 , r = 0. 713; Δ4 , r = 0. 740; Δ5 , r = 0. 747; all P lt; 0. 05) , whereas PAWP failed. The mean bias between CIart and CIpa was ( 0. 09 ±0. 5) L·min-1 ·m-2 ; the limit of agreement was ( - 0. 89 ～1. 07) L·min-1 ·m-2 . Conclusions There is good correlation between the two methods of PiCCO and PAC for reflecting the change of heart preload. PiCCO is reliable in hemodynamic monitoring in patients undergone lung transplantation.
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 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.
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.
Controlling intraoperative bleeding is the core technology of liver surgery, and it is also an important way to improve the benefits of liver surgery and reduce the risk of surgery. In recent years, a number of methods to maintain low central venous pressure have been proposed, including inferior vena cava clamping, restricted fluid infusion, postural changes, intraoperative assisted ventilation, intraoperative hypovolemic venous incision, etc. In addition, more and more indicators used to guide intraoperative fluid input management to maintain low central venous pressure have been discovered, including global end-diastolic volume and stroke volume variability. Therefore, this article summarizes the relationship between low central venous pressure and surgical effect in liver surgery, and the ways to achieve low central venous pressure on the basis of previous research.
Objective To study the effects of different levels of intra-abdominal pressure （IAP） on hemodynamics and oxygen metabolism in pig and to find the parameters early reflecting hemodynamics and oxygen metabolism of intra-abdominal hypertension （IAH）. Methods Fifteen pigs were anaesthetized, and trachea intubation and transfemoral cannula were performed then. Swan-Ganz catheters were inserted to pulmonary artery via internal jugular vein, and aeroperitoneum was set up by airing CO2. These pigs were randomly divided into three groups (5 pigs in each group) according to different levels of IAP （IAP10, IAP20, IAP30）. Hemodynamics and oxygen metabolism values were observed and recorded before airing, 6, 12, 18 and 24 hours after airing, respectively. Results There was no remarkable changes of hemodynamics and oxygen metabolism values in IAP10 group （Pgt;0.05）； When the IAP level reached 20 cm H2O, there was significant elevation （P＜0.01) in artery blood lacticacid （ABL）, and mixed venous oxygen saturation （SvO2） decreased significantly （P＜0.05) at 24 hours. When the IAP level reached 30 cm H2O, HR began to increase significantly at 18 hours after airing （P＜0.05). After 24 hours, all the indices of hemodynamics and oxygen metabolism were either significantly increased or decreased in IAP30 group. Two pigs in the group of IAP30 died during 24 hours after airing, while other pigs survived. Conclusion This study demonstrates that the hemodynamics and oxygen metabolism values begin to change in pigs when the IAP level reaches 20 cm H2O, and high level of IAP that lasted for 24 hours shows deterioration of hemodynamic and oxygenation levels. The indices of SvO2 and ABL can early reflect tissue oxygenation in IAH.