Correlation of Inferior Vena Cava Respiratory Variability Index with Central Venous Pressure and Hemodynamic Parameters in Ventilated Pigs with Septic Shock

Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure （CVP） of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.

Do Changes Occur in Hemodynamic Parameters, Hemogram, Renal Function and Serum Electrolytes during Percutaneous Nephrolithotomy? Its Correlation with Irrigation Fluid and Intravenous Fluid

Introduction: Percutaneous nephrolithotomy (PCNL) is a standard minimally invasive urological procedure for the treatment of large renal calculi. It is also associated with complications arising from absorption of irrigation fluid and intravenous fluid injection. We evaluated the changes occurring in vital and blood parameters during PCNL using 0.9% normal saline (NS) as an irrigation fluid. Materials and Methods: We prospectively studied 71 patients who underwent PCNL in our hospital between 2016 and 2018. NS (0.9%) was used as irrigation fluid in all patients. Changes in hemodynamics, hemogram, renal function tests and serum electrolytes were noted and assessed for significance using paired t-test. These changes were correlated with ASA grade, BMI, total operating time, total irrigation fluid used and total intravenous fluid used using Pearson’s correlation test. Results: A significant fall in serum creatinine was present (1.30 ± 0.96 vs. 1.24 ± 0.93) along with a rise in eGFR (85.39 ± 24.10 vs. 90.18 ± 22.58). A significant rise in serum potassium (4.34 ± 0.45 vs. 4.5 ± 0.56) and chloride levels (104.79 ± 3.51 vs. 106.69 ± 3.14) post-operatively was noted. A significant rise in pulse rate (80.84 ± 10.13 vs. 87.76 ± 13.12) and systolic blood pressure (127.67 ± 15.90 vs. 136.88 ± 19.56) post-operatively was noted. There was no significant change noted in hemoglobin, PCV, platelets and serum sodium levels. Total operating time and irrigation fluid volume showed a positive correlation with changes in eGFR, serum chloride, post-operative pulse rate and blood pressure values. Intravenous fluids volume correlated positively with changes in serum potassium, chloride, post-operative pulse rate and blood pressure values. Conclusion: High amount of irrigation fluid absorption can cause early post-operative changes in patients’ hemodynamics and blood indices. Overzealous hydration during PCNL with potassium containing fluids can also lead to hyperkalemia and hyperchloremic acidosis. Thus, early post-operative monitoring of serum electrolytes should be done in all patients after PCNL to prevent complications arising from dyselectrolytemia.

EXPERIMENTAL STUDY OF CHUANXIONG ON CEREBROVASCULAR HEMODYNAMIC PARAMETERS

In the experimental rabbit arteriosclerosis, the change of the cerebrovascular hemodynamic parameters (CVHP) and the effect of Chuanxiong (CX) on CVHP were observed. In arteriosclerosis group (AS group), the mean flow (Qmean), mean velocity (Vmean), maximal velocity (V max) and minimal velocity (Vmin) of the carotid blood flow and cerebrovascular compliance for zero pressure (CO) were significantly decreased (P < 0.05, 0.01), but the values of cerebrovascular peripheral resistance (R) and characteristic impedance (Zc) were significantly increased (P<0.05 and 0.01), and the value of R showed significant positive correlation with the extent of carotid lesions (P < 0.01). All indexes of CVHP of the Chuanxiong group (CX group) were close to and had no significant difference from those of the normal group (N group) but Qmean, Vmean, Vmin, CO and R were significantly better than those of the AS group (P<0.05, 0.01). These results showed that CX can effectively improve cerebrovascular hemodynamics.

Use of a rat model to characterize 35 arterial pulse wave parameters in a comparative study of isoflurane and Zoletil/ xylazine anesthesia and the effect of Acanthopanax senticosus extract

Background : Information obtained from arterial pulse waveforms (APW) can be usefulfor characterizing the cardiovascular system. To achieve this, it is necessary to know thedetailed characteristics of APWs in different states of an organism, which would allowAPW parameters (APW- Ps) to be assigned to particular (patho)physiological conditions.Therefore, our work aimed to characterize 35 APW- Ps in rats under the influence ofisoflurane (ISO) and Zoletil/xylazine (ZO/XY) anesthesia and to study the effect of rootextract from Acanthopanax senticosus (ASRE) in these anesthetic conditions.Methods : The right jugular vein of anesthetized rats was cannulated for the administrationof ASRE and the left carotid artery for the detection of APWs from which 35APW- Ps were evaluated.Results : We obtained data on 35 APW- Ps, which significantly depended on the anesthesia,and thus, they characterized the cardiovascular system under these two conditions.ASRE transiently modulated all 35 APW- Ps, including a transient decrease insystolic and diastolic blood pressure (BP) and heart rate or increases in pulse BP, d P /d t max , and systolic and diastolic areas. Whereas the transient effects of ASRE weresimilar, the extract had prolonged disturbing effects on the cardiovascular system inrats under ZO/XY but not under ISO anesthesia. This negative effect can result fromthe disturbance caused by ZO/XY anesthesia on the cardiovascular system.Conclusions : We characterized 35 APW- Ps of rats under ISO and ZO/XY anesthesiaand found that ASRE contains compounds that can modulate the properties of thecardiovascular system, which significantly depended on the status of the cardiovascularsystem. This should be considered when using ASRE as a nutritional supplementby individuals with cardiovascular problems.

Wall shear stress in intracranial aneurysms and adjacent arteries

Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

Computational Fluid Dynamics Analysis of the Aortic Coarctation

In this work, we first investigated the hemodynamic parameters in the case of a normal aortic arch anatomy and in the case of aortic coarctation anatomy, both generated by using CFX-ICEM-ANSYS simulations. Then, we compared these results with those obtained for a proposed model without and with aortic coarctation, while introducing a real tridimensional magnetic resonance imaging geometry in the simulation process. The conclusion is that our proposed model reproduces, with a high agreement, the real case obtained from imaging data.

Axonal loss and blood flow disturbances in the natural course of indirect traumatic optic neuropathy

Background Indirect traumatic optic neuropathy （TON） is an acute injury of the optic nerve associated with severe visual dysfunction, which may be a result of secondary mechanical injury and vascular disorder of the optic nerve due to trauma. We analyzed the natural course of axonal loss and blood flow disturbances in patients with indirect TON to find a possible therapeutic window. Methods A cohort of 54 patients with indirect TON recruited between October 2008 and October 2010 at Beijing Tongren Hospital was retrospectively analyzed. The patients were divided into no light perception group （NLP） and better than NLP （btNLP） group. Specifically, the thickness of the retinal nerve fiber layer （RNFL） measured by spectral domain optical coherence tomography （SD-OCT）, and hemodynamic parameters of the ophthalmic artery （OA）, central retinal artery （CRA） and posterior ciliary artery （PCA） were determined. Results Two weeks after injury, there was a statistically significant decrease in the thickness of RNFL in the btNLP group as compared with the fellow control eyes （P 〈0.05）. In contrast, in the NLP group, RNFL thickness slightly increased for 2 weeks following injury, then overtly reduced after 4 weeks （P 〈0.05）. Peak systolic velocity （PSV） of CRA was significantly decreased 4 weeks after injury （P 〈0.05） in both the NLP group and btNLP group （P 〈0.05）. The thickness of RNFL in the NLP group was negatively correlated with PSV of CRA after 1 week of injury （P 〈0.05, r=-0.962）. Conclusions SD-OCT is a useful supplement in detecting the axonal loss in TON. The dynamic change of the thickness of RNFL appears to correlate with the hemodynamic disturbances in the natural course of TON. The first 2 weeks following an injury is critical and should be considered as the therapeutic window for TON patients.

The application of color Doppler flow imaging in the diagnosis and therapeutic effect evaluation of erectile dysfunction

We aim to investigate the correlations between hemodynamic parameters, penile rigidity grading, and the therapeutic effects of phosphodiesterase type 5 inhibitors using color Doppler flow imaging after intracavernosal injection in patients with erectile dysfunction. This study involved 164 patients. After intracavernosal injection with a mixture of papaverine （60 mg）, prostaglandin E1 （10 μg）, and lidocaine （2%, 0.5-1 ml）, the penile vessels were assessed using color Doppler flow imaging. Penile rigidity was classified based on the Erection Hardness Score system as Grades 4, 3, 2 or 1 （corresponding to Schramek Grades Ⅴ to Ⅱ）. Then, the patients were given oral sildenafil （50-100 mg） and scored according to the International Index of Erectile Function （IIEF-5） questionnaire. The number of patients with penile rigidities of Schramek Grades Ⅱ to Ⅴ was 14, 18, 21, and 111, respectively. The IIEF-5 score was positively correlated with the refilling index of the penile cavernosal artery （r = 0.79, P 〈 0.05）, the peak systolic velocity （r= 0.45, P〈 0.05）, and penile rigidity （r= 0.75, P〈 0.05）, and was negatively correlated with the end diastolic velocity （r = -0.74, P 〈 0.05）. For patients with erectile dysfunction, both the IIEF-5 score after sildenafil administration, which is correlated with penile rigidity, and the hemodynamic parameters detected using color Doppler flow imaging may predict the effects of phosphodiesterase type 5 inhibitor treatment and could provide a reasonable model for the targeted-treatment of erectile dysfunction.