Venous Pressure In Patients Research Articles

Three-Dimensional inferior vena cava for assessing central venous pressure in patients with cardiogenic shock

Evaluation of central venous pressure (CVP) by inferior vena cava (IVC) measurements is crucial in the management of patients with cardiogenic shock to optimize drugs therapy. IVC has a complex 3-dimensional (3D) shape but measurements used to estimate CVP remain based on 2-dimensional (2D) echocardiographic imaging. The aim of this study was to investigate the accuracy of CVP estimation by IVC size and collapsibility index obtained using 3D-echocardiography compared with 2D in patients with cardiogenic shock. Eighty consecutive echocardiographic examinations performed in 33 patients (72 ± 15 years, left ventricular ejection fraction = 19 ± 10%) admitted for cardiogenic shock were prospectively included. Two and three-dimensional images of the IVC, performed at baseline and when CVP was ≤ 10 mmHg, were acquired simultaneous with invasive measurement of CVP, both at rest and during sniff test. 2D and 3D IVC diameters, 3D IVC area and collapsibility index (IVCCI) were assessed. The eccentricity index (EI) was computed from 3D data as the ratio of maximum over minimum IVC diameter. The cut-off value of 10 mmHg of CVP defined patient with euvolemia hemodynamic status. At rest, the IVC diameter averaged 23 ± 7 mm by 2D and 25 ± 8 × 19 ± 7 mm by 3D. IVC had an eccentric shape (EI = 1.3) that increased when CVP was ≤10 mmHg and during sniff test ( P < 0.001). IVC measurements by 2D and 3D were correlated with CVP. The best correlation was obtained with IVCCI derived from 2D diameters (R = -0.69) and 3D areas (R = −0.82). Using the cutoff value of 50% for IVCCI, a discrepancy between invasive CVP measurements and IVCCI has been observed for 11 examinations (13%) by 2D but only one was misclassified by 3D. Inter and intra-observer reproducibility for IVC area was 7 ± 6% and 5 ± 3%, respectively ( Fig. 1 ). In patients with cardiogenic shock, IVCCI from area by 3D echocardiography is reproducible and accurate to evaluate CVP.

Effects of SI and PCV on respiratory mechanics, early central drive and hemodynamics in patients with ARDS.

Effects of sustained inflation (SI) and pressure- controlled ventilation (PCV) on respiratory mechanics, early central drive, and hemodynamics in patients with acute respiratory distress syndrome (ARDS) were investigated and compared. A retrospective analysis of 26 patients with ARDS, who were admitted to the Yiwu Central Hospital from March 2015 to March 2016, was performed. According to the ventilation method adopted by the patients with ARDS, 13 patients who received SI treatment were included in the SI group and 13 patients who received PCV treatment were included in the PCV group. The condition of central drive of the patients in the two groups was recorded and calculated continuously before and after recruitment maneuver (RM), the changes of each indicator of the respiratory function and hemodynamics were recorded and calculated before and after RM at 1, 10, 20 and 30 min. The differences were not statistically significant when comparing PIP, Pplate and Crs in patients in the SI group and the PCV group before RM with those after RM at 1, 10, 20 and 30 min (P>0.05), the differences were not statistically significant when comparing heart rate and mean arterial pressure in patients in the SI group and the PCV group before RM with those after RM at 1, 10, 20 and 30 min (P>0.05). Ηowever, central venous pressure in patients in the SI group after RM at 10 and 20 min was significantly higher than that in the PCV group, and the differences were statistically significant (P<0.05). VT/RMS, VE/RMS and ΔPdi/RMS in the SI group and the PCV group after RM were significantly higher than those before RM, and the differences were statistically significant (P<0.05). There was little difference in the effect between SI and PCV on respiratory mechanics, early central drive and hemodynamics in patients with ARDS, and both mechanical ventilation methods enhanced the effect of central-mechanical-ventilation coupling after RM. Therefore, the two mechanical ventilation methods, SI and PCV, were equally available for patients with ARDS.

Reliability and Variability of Hepatic Venous Pressure Gradient as a Surrogate of Portal Pressure Gradient: Insights from a Computational Model-Based Study

Hepatic venous pressure gradient (HVPG) measurement has been increasingly accepted as a useful means for indirectly measuring portal venous pressure in patients with portal hypertension (PHT) caused by chronic liver diseases. Despite the existence of numerous studies addressing the clinical utility of HVPG measurement, it is as yet unclear how the accuracy of measured HVPG as a surrogate of portal pressure gradient (PPG) is influenced by the pathological status of the hepatic circulation that not only changes with the progression of liver disease but also differs considerably among patients. In addition, it remains unclear whether HVPGs measured in different hepatic veins (HVs) are exchangeable, and if not, what factors determine inter-HV HVPG differences? In this context, we developed a stochastic computational model of the hepatic circulation, and performed a series of model-based numerical experiments to quantitatively investigate the respective/combined effects of various hepatic vascular properties on the accuracy of HVPG measurement. Major findings were: 1) a variation in presinusoidal portal vascular resistance significantly altered the difference between HVPG and PPG, whereas, an enhancement in portosystemic collateral flow (caused by growth of portosystemic collateral vessels or shunt intervention) tended to improve the accuracy of HVPG measurement; and 2) misdiagnosis of clinically significant PHT with HVPG was more likely to occur in the presence of high splanchnic vascular resistance combined with low presinusoidal and postsinusoidal portal vascular resistances. Stochastic numerical simulations of HVPG measurement in multiple HVs revealed that HVPGs measured in the right and middle HVs were basically exchangeable, whereas HVPGs measured in the left HV were relatively lower. The difference in measured HVPG between the middle/left and right HVs correlated positively with the proportion of blood flow rate through the middle/left HV, implying that the lower reading of left-HV HVPG measurement is due primarily to the lower blood flow rate through the HV. These findings may contribute as useful theoretical references for guiding data interpretation or choosing a proper HV for implementing catheterization in the clinical application of HVPG measurement.

The Importance of Ambulatory Venous Hypertension Should Be Revised

Inadequate decrease of venous pressure in patients with varicose vein while walking and exercising is called ambulatory venous hypertension (AVH). It has been considered as the main cause of chronic venous insufficiency. However, venous pressure in lower limbs while standing (95 mmHg) and sitting (70 mmHg) remains higher most of the day compared to AVH (healthy persons 26 mmHg, patients with varicose veins 41 mmHg). Published values of venous pressure in lower limbs in healthy persons and in patients with varicose veins in lower limbs, obtained while lying, standing, standing with small movements, sitting and walking, and the reported times, were used to calculate the mean venous pressure for 24 hours. Photoplethysmographic testing was used for indirect evaluation of venous haemodynamics in intensive and moderate exercise in sitting subjects. Patients with varicose veins restrict standing times; taking into account this fact, mean venous pressure for 24 hours reached 48.71 mmHg in healthy persons and 49.56 mmHg in patients with varicose vein (CEAP C2 stage). The difference is very small and cannot be the fundamental pathophysiological mechanism of development of venous insufficiency. Conclusion: 24-hour venous pressure in legs in healthy persons and in persons with varicose veins in lower limbs shows only a very small difference. The importance of AVH, particularly in initial stages of the disease, should be revised.

The Effect of Intravenous Injection of Amiodarone on Central Venous Pressure in Patients Undergoing Coronary Artery Bypass Graft Surgery

The Effect of Intravenous Injection of Amiodarone on Central Venous Pressure in Patients Undergoing Coronary Artery Bypass Graft Surgery

Renal dysfunction is associated with higher central venous pressures in patients with Fontan circulation.

Elevated central venous pressure (CVP) has deleterious effects on several organ systems in patients with Fontan circulation. However, the relationship between CVP and estimated glomerular filtration rate (eGFR) has not been assessed in patients with Fontan circulation. Patients with Fontan circulation whose hemodynamics were assessed by catheterization between 1987 and 2015 and had a serum creatinine measured within 72 hours prior to the procedure were included for analysis. Patients with primary kidney disease were excluded. Renal function was calculated by "bedside Schwartz" equation in children (< 18 years) and Modification of Diet in Renal Disease equation in adults. Renal dysfunction (RD) was defined by eGFR < 90mL/min/1.73m2 . Fontan patients with and without RD were compared based on demographics, co-morbidities, medication use, echocardiographic findings, hemodynamics assessed at time of catheterization, and laboratory testing values. Sixty-seven patients with Fontan circulation met inclusion criteria and 15 patients (22%) had RD; eGFR (mL/min/1.73m2 ) was 60-89in 13 (87%), 45-59in 1 (7%), and 30-45in 1 (7%). Compared to patients with eGFR equal to or greater than 90, patients with RD had higher CVP (18.0 [15.0-21.0] mm Hg vs 13.5 [12.3-16.0] mm Hg (P = 0.001), lower pulmonary blood flow 2.2 [1.9-2.6] L/min/m2 vs 2.8 [2.3-3.7] L/min/m2 , higher ventricular end-diastolic pressure 10.5 [7.0-17.3] mm Hg vs 8.0 [6.0-10.0] mm Hg (P = 0.050), were more likely to have worse atrioventricular valve regurgitation (P = 0.02) and were more likely to be African American (P = 0.009). In this study population, renal dysfunction in patients with Fontan circulation is associated with increased CVP and factors that affect CVP. African Americans with Fontan circulation may be at particular risk for renal dysfunction. Continued investigation of the effects of venous congestion on kidneys and other factors associated with renal dysfunction in patients with Fontan circulation is warranted.

Three-Dimensional Inferior Vena Cava for Assessing Central Venous Pressure in Patients with Cardiogenic Shock

The inferior vena cava (IVC) has a complex three-dimensional (3D) shape, but measurements used to estimate central venous pressure (CVP) remain based on two-dimensional (2D) echocardiographic imaging. The aim of this study was to investigate the accuracy of IVC size and collapsibility index obtained by 3D echocardiography for assessing CVP in patients with cardiogenic shock. Eighty consecutive echocardiographic examinations performed in 33 patients (mean age, 72±15years; mean left ventricular ejection fraction, 19±10%) admitted for cardiogenic shock were prospectively included. Two-dimensional and 3D images of the IVC were acquired simultaneously with invasive measurement of CVP, both at rest and during a sniff test. IVC diameters, 3D IVC area, and IVC collapsibility index (IVCCI) were assessed. The eccentricity index was computed from 3D data as the ratio of maximum to minimum IVC diameter. A cutoff value of 10mm Hg for CVP defined patients with euvolemic hemodynamic status. At rest, IVC diameter averaged 23±7mm by 2D imaging and 25±8×19±7mm by 3D imaging. The IVC had an eccentric shape (eccentricity index=1.3) that increased when CVP was ≤10mm Hg and during the sniff test (P<.001). IVC measurements by 2D and 3D imaging were correlated with CVP. The best correlation was obtained with IVCCI derived from 2D diameters (R=-0.69) and 3D areas (R=-0.82). Using a cutoff value of 50% for IVCCI, 11 examinations were misclassified by 2D imaging and only one by 3D imaging. Inter- and intraobserver reproducibility for IVC area was 7±6% and 5±3%, respectively. In patients with cardiogenic shock, IVCCI from area by 3D echocardiography is reproducible and accurate to evaluate CVP.

Effect of Body Mass Index on Venous Sinus Pressures in Idiopathic Intracranial Hypertension Patients Before and After Endovascular Stenting.

Elevated body mass index (BMI) has been correlated with worse outcomes after treatment for idiopathic intracranial hypertension (IIH). Venous sinus stenting (VSS) has emerged as a safe and effective treatment for a subset of patients with IIH and evidence of venous sinus stenosis. However, the association between BMI and the efficacy of VSS remains poorly characterized. To determine, in a retrospective cohort study, the effect of BMI on preoperative mean intracranial venous pressure (MVP) and post-VSS outcomes. We performed a retrospective evaluation of a prospectively collected database of patients with IIH and intracranial venous sinus stenosis who underwent VSS. Patient demographics and treatment factors, including pre- and postprocedural trans-stenosis pressure gradients, were analyzed to identify the relationship between BMI and outcomes after VSS. Increasing BMI was significantly correlated with higher maximum MVP (P = .013) and higher trans-stenosis pressure gradient (P = .043) prior to treatment. The degrees of improvement in maximum MVP and pressure gradient after VSS were greatest for obese and morbidly obese patients (BMI > 30 kg/m2). Maximum poststent MVP, clinical outcomes, and stent-adjacent stenosis requiring retreatment after VSS were not significantly associated with BMI. We provide direct evidence for a positive correlation between BMI and intracranial venous pressure in patients with IIH. VSS affords a significantly greater amelioration of intracranial venous hypertension and stenosis for IIH patients with higher BMIs. As such, obesity should not be a deterrent for the use of VSS in the management of IIH.

Pseudoexfoliation syndrome and episcleral venous pressure

Introduction. Pseudoexfoliation syndrome (PEX) is a relatively widespread generalized age-related disease, in which abnormal fibrillar extracellular material is produced and accumulates in many tissues including vessels. Glaucoma occurs more commonly in eyes with PEX than in those without it. Episcleral venous pressure (EVP) is an important determinant of intraocular pressure (IOP). It seems reasonable to evaluate episcleral venous pressure in patients with PEX. Purpose. To evaluate episcleral venous pressure in patients with PEX. Methods. 540 eyes of 270 patients were enrolled in the prospective study. We evaluated episcleral venous pressure. Results. EVP in total vein compression in lower-nasal quadrant (mmHg) in main group(with PEX) was 14.0±3.29, in control group No. 1 (non PEX, adults) - 14.38±3.77, in control group No. 2 (non PEX, young) - 10.91±2.34. EVP in total vein compression in lower-temporal quadrant (mmHg) in main group was 15.1±3.31, in control group No. 1 - 15.76±3.45, in control group No. 2 - 11.00±2.16. Difference in episcleral venous pressure between main group and age-matched control group No. 1 was not significant, and between main group and control group No. 2 was significant. Conclusion. EVP level is not influenced by PEX, but is influenced by age.

Point Shear Wave Elastography to Evaluate and Monitor Changing Portal Venous Pressure in Patients with Decompensated Cirrhosis

This study evaluated whether the stiffness of the liver and spleen, measured using the point shear wave elastography (pSWE) technique, correlates with portal venous pressure (PVP) and whether the result extends to estimate the diminishing change in PVP (ΔPVP) in patients with decompensated cirrhosis. We evaluated the data of 67 prospectively enrolled patients who underwent both transjugular intrahepatic portosystemic shunt (TIPS) and pSWE. The stiffness of liver and spleen were evaluated by measuring shear wave velocity (SWV) to determine the statistical correlation with PVP. We also analyzed whether change in SWV (ΔSWV) correlates with ΔPVP. The correlations were assessed with Spearman's rank correlation coefficients. Furthermore, receiver operating characteristic (ROC) curves were constructed to evaluate diagnostic capacity of ΔSWV. Spleen stiffness (SS) was positively correlated with PVP before and after TIPS (p < 0.002), although no correlation between liver stiffness and PVP was detected. A strong relationship between ΔSWV in SS and ΔPVP change in portal hypertension (r = 0.871) was also found in the overall population. The area under the ROC curve for the diagnosis of TIPS technical success was 0.869 and at a ΔSWV cut-off value of 0.36 m/s sensitivity was 77%. Measurement of SS can be used for non-invasive assessment and monitoring of PVP in patients with decompensated cirrhosis.

Splenic Enlargement and Bone Marrow Hyperplasia in Patients Receiving Trastuzumab-Emtansine for Metastatic Breast Cancer.

An association between trastuzumab-emtansine (T-DM1) and splenic enlargement is reported in preclinical data, and has been noted anecdotally in patients receiving T-DM1 at our institution. Use of whole-body MRI examinations (WB-MRI) allows for detailed bone marrow assessment and semi-automated splenic volume calculations. To retrospectively evaluate changes in splenic volume versus evidence of bone marrow hyperplasia and/or changes in portal venous pressure in patients receiving T-DM1 for metastatic breast cancer. Twelve metastatic breast cancer patients underwent 29 WB-MRIs before and during T-DM1 therapy. Splenic volume, portal vein diameter, bone marrow diffusion-weighted normalised signal intensity (nSI), quantitative water diffusivity (apparent diffusion coefficient, ADC) and fat fraction (rF%) were measured and correlated. Splenic volume increases were observed in 92% of patients. Mean splenic volume increased from 144cm3 (95% CI 110-177cm3) to 209cm3 (95% CI 161-257cm3) on T-DM1 therapy (p = 0.006). Splenic volume increases correlated with treatment duration (r2 = 0.43). Bone marrow hyperplasia was evidenced by an increase in bone marrow nSI (3.5 to 4.8, p = 0.12), and decreases in rF% (64.3% to 57.3%, p = 0.12) and ADC (655μm2/s to 543μm2/s, p = 0.11). No changes to portal vein diameter were seen. Previously unreported increases in splenic volume and bone marrow hyperplasia are observed on WB-MRI in patients on T-DM1 therapy. Caution must be applied to avoid misinterpreting T-DM1-induced bone marrow hyperplasia as diffuse disease progression in bone.

Effect of Positive End-Expiratory Pressure on Central Venous Pressure in Patients under Mechanical Ventilation.

Finding the probable governing pattern of PEEP and CVP changes is an area of interest for in-charge physicians and researchers. Therefore, the present study was designed with the aim of evaluating the relationship between the mentioned pressures. In this quasi-experimental study, patients under mechanical ventilation were evaluated with the aim of assessing the effect of PEEP change on CVP. Non-trauma patients, over 18 years of age, who were under mechanical ventilation and had stable hemodynamics, with inserted CV line were entered. After gathering demographic data, patients underwent 0, 5, and 10 cmH2O PEEPs and the respective CVPs of the mentioned points were recorded. The relationship of CVP and PEEP in different cut points were measured using SPSS 21.0 statistical software. 60 patients with the mean age of 73.95 ± 11.58 years were evaluated (68.3% male). The most frequent cause of ICU admission was sepsis with 45.0%. 5 cmH2O increase in PEEP led to 2.47 ± 1.53 mean difference in CVP level. If the PEEP baseline is 0 at the time of 5 cmH2O increase, it leads to a higher raise in CVP compared to when the baseline is 5 cmH2O (2.47 ± 1.53 vs. 1.57 ± 1.07; p = 0.039). The relationship between CVP and 5 cmH2O (p = 0.279), and 10 cmH2O (p = 0.292) PEEP changes were not dependent on the baseline level of CVP. The findings of this study revealed the direct relationship between PEEP and CVP. Approximately, a 5 cmH2O increase in PEEP will be associated with about 2.5 cmH2O raise in CVP. When applying a 5 cmH2O PEEP increase, if the baseline PEEP is 0, it leads to a significantly higher raise in CVP compared to when it is 5 cmH2O (2.5 vs. 1.6). It seems that sex, history of cardiac failure, baseline CVP level, and hypertension do not have a significant effect in this regard.

Peripheral venous pressure as a reliable predictor for monitoring central venous pressure in patients with burns.

Sir, The article by Sherif et al.[1] on peripheral venous pressure (PVP) was very interesting. Fluid resuscitation of burns patient is extremely important part of initial management. Peripheral access for fluid resuscitation must be used as it helps in faster initiation of fluid therapy. The use of PVP to monitor hemodynamics and volume status is very innovative. The volume of fluid infusion is calculated as per the formulae based on percentage body surface area affected by burns. The use of hemodynamic monitoring has not been proven to be of much importance in the management of such patients. Most of the studies quoted in this study that have shown any use of invasive monitoring have used pulmonary artery catheter. The benefit of both central venous pressure (CVP) and pulmonary capillary wedge pressure for hemodynamic monitoring have been questioned in various trials and meta-analyses.[2,3] We doubt if there can be a worthwhile role of PVP to help in volume resuscitation of burn patients. The use of central venous access is also important in the hemodynamically unstable patient because it helps to give vasopressor medications, which cannot be given by the peripheral route. These patients may also need mechanical ventilation, which mandates the use of sedative and analgesic medication. Thus in such patients requiring multiple infusions central venous access would be necessary as peripheral access would not be satisfactory in such cases. The Bland-Altman analysis has shown in the study a difference of −1.2 with an standard deviation of +1.96, which means that PVP and CVP can differ by a range of 5.12 mm Hg more to 2.72 mm Hg less.[4] This is not a clinically acceptable margin of error for the use of PVP as a surrogate for CVP. The interpretation of data is thus always a clinical judgment. These findings are similar to the Tugrul et al.[5] study that showed a good correlation but poor clinical agreement. We feel the range is too wide for effective utilization at the bedside. The [Figure 2] is written to be depicting the hourly mean difference between CVP and PVP but in the graph there is no hour axis. We think it's the scatter diagram of the data which has been wrongly labeled. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Peripheral venous pressure as a reliable predictor for monitoring central venous pressure in patients with burns.

Background:Optimizing cardiovascular function to ensure adequate tissue oxygen delivery is a key objective in the care of critically ill patients with burns. Hemodynamic monitoring may be necessary to optimize resuscitation in serious burn patients with reasonable safety. Invasive central venous pressure (CVP) monitoring has become the corner stone of hemodynamic monitoring in patients with burns but is associated with inherent risks and technical difficulties. Previous studies on perioperative patients have shown that measurement of peripheral venous pressure (PVP) is a less invasive and cost-effective procedure and can reliably predict CVP.Objective:The aim of the present prospective clinical study was to determine whether a reliable association exists between changes in CVP and PVP over a long period in patients admitted to the Burns Intensive Care Unit (BICU).Subjects and Methods:The CVP and PVP were measured simultaneously hourly in 30 burns patients in the BICU up to 10 consecutive hours. The predictability of CVP by monitoring PVP was tested by applying the linear regression formula and also using the Bland–Altman plots of repeated measures to evaluate the agreement between CVP and PVP.Results:The regression formula revealed a reliable and significant association between CVP and PVP. The overall mean difference between CVP and PVP was 1.628 ± 0.84 mmHg (P < 0.001). The Bland–Altman diagram also showed a perfect agreement between the two pressures throughout the 10 h period.Conclusion:Peripheral venous pressure measured from a peripheral intravenous catheter in burns patients is a reliable estimation of CVP, and its changes have good concordance with CVP over a long period of time.

Can Stroke Volume Variation Be an Alternative to Central Venous Pressure in Patients Undergoing Kidney Transplantation?

BackgroundStroke volume variation (SVV) is known to be a simple and less invasive hemodynamic parameter for evaluating fluid responsiveness and preload status. Central venous pressure (CVP) has been targeted to achieve an adequate level for improving the graft perfusion and long-term graft function in kidney transplantation (KT) recipients, despite the various potential complications. The aim of this study was to investigate whether SVV could substitute for CVP in guiding intravascular volume management during KT. MethodsThis retrospective study evaluated 635 patients who underwent KT because of end-stage renal disease. Hemodynamic variables including CVP and SVV were obtained before skin incision (T1), 5 minutes after iliac vein clamping (T2), and 10 minutes after renal graft reperfusion (T3). The ability of SVV to predict CVP level was investigated with receiver operating characteristic (ROC) curve analysis. ResultsCVPs were 6.0 ± 2.6, 8.6 ± 2.7, and 9.3 ± 2.5 mm Hg, and SVVs were 6.9 ± 3.0, 5.0 ± 2.1, and 4.3 ± 2.1% at T1, T2, and T3, respectively. ROC analysis showed that the discriminative power of SVV was fairly good with an area under the ROC curve of 0.70 (95% confidence interval, 0.67–0.72) for a CVP of 8 mm Hg, and that an optimal cutoff value of SVV was 6% as an alternative to CVP of 8 mm Hg during KT. ConclusionsSVV may replace CVP in the volume management of patients who have undergone KT. Our results suggest that SVV can guide volume management to improve graft perfusion at critical time points during KT.

The Effect of Central Retinal Venous Pressure in Patients with Central Retinal Vein Occlusion and a High Mean Area of Nonperfusion

To evaluate the effect of central venous pressure (CVP) on visual outcomes and retinal ischemic consequences in patients with central retinal vein occlusion (CRVO). Prospective, single-center cohort study. Eighty-eight patients with CRVO and a high overall mean area (21.6 disc areas) of capillary nonperfusion (CNP) who were followed for 18 months before the availability of intravitreal therapy and who were offered standard care of the time. Patients were evaluated at baseline and at 3, 8, and 18 months. At each study visit, measurements of CVP, best-corrected visual acuity (BCVA), area of CNP, retinal fluorescein transit time (FTT), and an evaluation for rubeosis iridis were performed. Evaluation of the effect of different levels of CVP on BCVA, retinal blood flow, and the development of retinal ischemia and rubeosis iridis. Mean BCVA was significantly higher in patients with lower CVP at all time points (P<0.0001). The area of CNP increased significantly with higher levels of CVP and progressed with time. The development of rubeosis iridis was significantly associated with CVP at all time points and was present in 5.6%, 27.9%, and 88.9% of those with low, moderate, and high CVP levels, respectively (P<0.0001), at the 18-month conclusion. Retinal blood flow as measured by FTT was reduced with higher levels of CVP. Spontaneous lowering of CVP had beneficial effects on BCVA, although this diminished with time. Eyes with increased CVP after more severe CRVO demonstrate significantly reduced vision, reduced retinal blood flow, a higher incidence of rubeosis iridis, and larger areas of CNP that correlate with the degree of CVP elevation.

Cerebral Circulation in Patients With Fontan Circulation: Assessment by Carotid Arterial Wave Intensity and Stiffness

Information about the cerebral circulation in the Fontan physiology is scarce. We tested our hypothesis that cerebral perfusion is impaired in the Fontan circulation by analyzing wavefront behavior (wave intensity) and assessing arterial stiffness at the carotid artery. The carotid arterial wave intensity and stiffness were computed in 34 consecutive Fontan patients (11.5±8.6 years) and 20 control subjects (13.4±6.0 years) using an echocardiographic vascular tracking system, which enabled simultaneous measurements of instantaneous carotid arterial pressure and flow velocity. The carotid arterial blood flow was significantly lower in the Fontan patients than in the controls (p<0.05). Wave intensity analysis demonstrated a significant decrease in the compression and acceleration wave, an important forward traveling wave for cerebral circulation, in the Fontan patients compared with the control subjects (31.0±2.6 versus 48.1±4.4 mm Hg⋅m⋅s3⋅10(3); p=0.001). In addition, the negative wave intensity normalized to the first positive wave, representing a wave reflection from peripheral cerebral vessels, was significantly increased in the Fontan patients compared with that in control subjects. Carotid arterial stiffness and central venous pressure were also significantly increased in the Fontan patients and were independent determinants of the decreased first positive wave, suggesting the pathophysiologic importance of carotid arterial stiffness and central venous pressure as inflow and outflow resistance to the cerebral circulation, respectively, in the Fontan physiology. These results suggest impaired cerebral perfusion caused by vascular stiffening and high central venous pressure in patients with Fontan circulation. Longitudinal studies examining the association between cerebral circulation and neurodevelopmental outcome after Fontan operation are warranted.

The condition of the microcirculatory channel of the nail bed of the upper extremities and changes of central venous pressure in patients with the second stage of essential hypertension depending on the structure of the diurnal rhythm of arterial pressure

The peculiarities of changes of the microcirculation of the nail-bed and central venous pressure (CVP) have been presented in the poper in patients the with 2nd stage of essential hypertension depending on different variants of the circadian rhythm of arterial pressure. An inverse interdependence has been established between the level and a decrease of the specific gravity of the functioning capillaries in the patients with a low (non-dipper) and negative (night-picker) diurnal index of arterial pressure that con be used as diagnostic criteria of a high risk of possible complications of essential hypertension.

The influence of positive end-expiratory pressure on central venous pressure in patients with severe craniocerebral injury

To observe the impact of positive end-expiratory pressure (PEEP) on central venous pressure (CVP) in mechanically ventilated patients with severe craniocerebral injury. A prospective, interventional, self-control study was conducted. Thirty severe craniocerebral injury patients with central respiratory failure were enrolled. The changes in CVP, mean arterial pressure (MAP), heart rate (HR) and pulse oxygen saturation [SpO2] were monitored at different PEEP levels [0, 3, 6, 9, 12, 15 cm H2O; 1 cm H2O=0.098 kPa] during mechanical ventilation and after weaning of mechanical ventilation. The influences of PEEP and its discontinuance on haemodynamics and oxygenation were analyzed. The values of CVP [cm H2O] were increased when PEEP increased (from 7.9±3.1 to 13.1±3.7), a linear correlation was found (R=0.509, P=0.000), and linear regression equation was CVP [cm H2O]=7.774+0.368×PEEP [cm H2O]; CVP was elevated about 0.368 cm H2O when PEEP increased 1 cm H2O. CVP values significantly decreased during discontinuance of mechanical ventilation, as compared to those measured at different PEEP levels during mechanical ventilation (F=24.429, P=0.000). The values of MAP, HR and SpO2 showed no significant change with increase of PEEP levels [MAP (mm Hg, 1 mm Hg=0.133 kPa): from 81.6±10.4 to 85.6±10.6; HR (beats per minute): from 79.9±13.5 to 88.1±15.4; SpO2: from 0.968±0.036 to 0.975±0.033, all P>0.05] in mechanically ventilated patients, but discontinuance of mechanical ventilation could significantly increase the levels of MAP and HR (95.3±8.4 and 94.9±10.3, respectively) and lower SpO2 levels (0.928±0.036, all P=0.000). CVP values were overestimated during an increase in PEEP in mechanically ventilated patients with severe craniocerebral injury. CVP was increased about 0.368 cm H2O following an increase of PEEP of 1 cm H2O, whereas the values of MAP, HR and SpO2 showed no significant change with increase in PEEP levels. This study could offer a theoretical base in the correct assessment of CVP values at different PEEP levels without discontinuation of mechanical ventilation.

Abstract 17313: Bedside Ultrasound for Serial Assessment of Central Venous Pressure in Patients with Volume Overload

Background: Using bedside ultrasound, we have previously shown that a greater than 17% increase in internal jugular vein (IJ) cross sectional area (CSA) during Valsalva rules out elevated right atrial pressure (RAP &gt; 12mmHg, NPV 94%). This occurs because venous compliance increases nonlinearly with increasing pressure. Here, we sought to validate this US test in the first longitudinal study of patients undergoing acute volume removal during hemodialysis (HD) as well as patients undergoing diuresis for acute decompensated heart failure (ADHF). Methods: Images of the right IJ were captured using portable bedside US before and during the strain phase of a standardized Valsalva maneuver (Fig 1) on hospitalized patients who were either admitted for ADHF or undergoing HD. For HD patients (n=11), percent change in IJ CSA with Valsalva (ΔCSA) was assessed both before and after HD treatment. For ADHF patients (n=37), ΔCSA was measured both at admission and discharge. Results: For HD patients, analysis of US images detected elevated filling pressures (ΔCSA &lt;17%) in 11 of the patients studied. In these subjects, a mean fluid volume of 1.8L was removed and 10 subjects demonstrated an increased ΔCSA after HD (ΔCSA increase of 45 ± 40%, p17% indicating restoration of normal filling pressures. Of the 37 ADHF patients studied with elevated filling pressures at admission (ΔCSA &lt;17%), 27 demonstrated euvolemia after diuresis (ΔCSA increase of 57 ± 157%, p&lt;0.01) and an average length of stay of 7.8 days. Conclusion: US of the IJ can be used to examine intravascular volume status in response to fluid changes that occur over the course of hours (HD) or days (ADHF). This simple bedside technique could be utilized for monitoring volume changes, both acutely and longer term, to guide volume management and overcome some of the difficulties associated with traditional visual assessment of jugular venous pulsations.