Increase In Central Venous Pressure Research Articles

Airway pressure release ventilation (APRV) versus pressure support ventilation (PSV)-A prospective intervention trial comparing haemodynamic parameters in intensive care patients.

Assisted mechanical ventilation may alter the pressure profile in the thorax compared to normal breathing, which can affect the blood flow to and from the heart. Studies suggest that in patients with severe lung disease, airway pressure release ventilation (APRV) may be haemodynamically beneficial compared to other ventilator settings. The primary aim of this study was to investigate if APRV affects cardiac index in intubated intensive care patients without severe lung disease when compared to pressure support ventilation (PSV). The secondary aim comprised potential changes in other haemodynamic and ventilatory parameters. Twenty patients were enrolled in the intensive care unit (ICU) at Sahlgrenska University Hospital. Eligible patients met the inclusion criteria; 18 years of age or above, intubated and mechanically ventilated, triggering and stable on PSV mode, with indwelling haemodynamic monitoring via a pulse-induced continuous cardiac output (PiCCO) catheter. The study protocol started with a 30-min interval on PSV mode, followed by a 30-min interval on APRV mode, and finally a 30-min interval back on PSV mode. At the end of each interval, PiCCO outputs, ventilator outputs, arterial and venous blood gas analyses, heart rate and central venous pressure were recorded and compared between modes. There was no significant difference in cardiac index (3.42 vs. 3.39 L/min/m2) between PSV and APRV, but a significant increase in central venous pressure (+1.0 mmHg, p = .027). Furthermore, we found a significant reduction in peak airway pressure (-3.16 cmH2O, p < .01) and an increase in mean airway pressure (+2.1 cmH2O, p < .01). No statistically significant change was found in oxygenation index (partial pressure of O2 [pO2]/fraction of inspired oxygen) nor in other secondary outcomes when comparing PSV and APRV. There was no significant association between global end-diastolic volume index and cardiac index (R2 = 0.0089) or central venous pressure (R2 = 0.278). All parameters returned to baseline after switching the ventilator mode back to PSV. We could not detect any changes in cardiac index in ICU patients without severe lung disease during APRV compared to PSV mode, despite lower peak airwaypressure and increasedmean airway pressure.

AN UNCOMMON CASE OF SUPERIOR VENA CAVA SYNDROME FOLLOWING CARDIAC SURGERY

Abstract Superior vena cava (SVC) syndrome (SVCS) is due to the obstruction of the SVC leading to swelling of the upper body and to low cardiac output. Non tumoral causes, mainly thrombosis of endovascular devices, account for 30% of cases. We report a case of acute iatrogenic SVCS. A 7 years old 16 kg boy underwent mitral valve surgery in severe rheumatic mitral regurgitation. After induction a 15 cm 5.5 Fr 3 lumens central venous catheter (CVC) was inserted in the right internal jugular vein (IJV) under ultrasound guidance without issues. After achieving proper anticoagulation ascending aorta (18 Fr) and bicaval cannulation were performed (20 Fr single stage cannula with right–angled metal tip in the SVC and 26 Fr single stage cannula in the inferior vena cava). Cardiopulmonary bypass (CPB) was performed with pediatric circuit and the mitral valve was repaired. Despite apparently good result of the repair and uneventful weaning from CPB a more accurate transesophageal echo (TEE) showed moderate iatrogenic mitral stenosis. Cannulation was re–performed with same size cannulas and mitral valve replacement (St.Jude 25 mm) was provided. After weaning from CPB with mild cardiovascular support (adrenaline 0.03 mcg/kg/min and noradrenaline 0.05 mcg/kg/min) the TEE showed no abnormalities and the patient was transferred to the ICU in stable conditions. The central venous pressure (CVP) never raised over 10 mmHg. In the ICU the patient developed sinus tachicardia and hypotension, unresponsive to fluids and vasopressors, and swelling of the face with no increase in CVP. The chest Xray showed enlargement of the right upper mediastinum with TEE evidence of accellerated flow in the SVC around the CVC (fig.1). The patient was taken to the operating room and a too tigh pursue string suture was found on the SVC. After optimization of the suture the flow through the SVC was restored with immediate clinical improvement and de–escalation of the cardiovascular support. The face oedema quickly decreased allowing extubation on the day after surgery. The following course was uneventful. SVCS is a life threatening complication of cardiac surgery. A too tight pledgetted pursue–string suture is an uncommon cause compared to clot compression. The CVP measured by a IJV CVC is generally elevated in SVCS, but in our case the tip of the CVC was downstream to the stenosis so showing normal values. Multimodal monitoring is mandatory to lead to emergency surgical treatment in case of need.

Cannon A wave validation as a diagnostic tool in paroxysmal supraventricular tachycardias.

The presence of cannon A waves, the so called "frog sign", has traditionally been considered diagnostic of atrioventricular nodal re-entrant tachycardia (AVNRT). Nevertheless, it has never been systematically evaluated. The aim of this study is to assess the independent diagnostic utility of cannon A waves in the differential diagnosis of supraventricular tachycardias (SVTs). We prospectively included 100 patients who underwent an electrophysiology (EP) study for SVT. The right jugular venous pulse was recorded during the study. In 61 patients, invasive central venous pressure (CVP) was registered as well. CVP increase is thought to be related with the timing between atria and ventricle depolarization; two groups were prespecified, the short VA interval tachycardias (including typical AVNRT and atrioventricular reciprocating tachycardia (AVRT) mediated by a septal accessory pathway) and the long VA interval tachycardias (including atypical AVNRT and AVRT mediated by a left free wall accessory pathway). The relationship between cannon A waves and AVNRT did not reach the statistical significance (OR: 3.01; p=.058); On the other hand, it was clearly associated with the final diagnosis of a short VA interval tachycardia (OR: 10.21; p<.001). CVP increase showed an inversely proportional relationship with the VA interval during tachycardia (b=-.020; p<.001). CVP increase was larger in cases of AVNRT (4.0mmHg vs. 1.2mmHg; p<.001) and short VA interval tachycardias (3.9mmHg vs. 1.2mmHg; p<.001). The presence of cannon A waves is associated with the final diagnosis of short VA interval tachycardias.

Retinal haemorrhage after cardiopulmonary resuscitation of a patient

Aims/Purpose: We present a rare case of a patient who presented with bilateral retinal haemorrhage after cardiopulmonary resuscitation (CPR).Methods: A 37‐year‐old man, with a medical history of allergic bronchial asthma and a BMI &gt;35, was referred to our emergency department from the cardiology clinic. He complained of sudden, painless, monocular visual acuity reduction after cardiac arrest and CPR because of an acute myocardial infarction (right coronary). He underwent a complete ophthalmic examination, as well as multimodal imaging and he was under close monitoring for the following months.Results: In his initial ophthalmic examination, best corrected visual acuity was 0.1 in his right eye and 1.0 in his left eye (Snellen's chart). Intraocular pressure was 14 mmHg and 15 mmHg in his right and left eye, respectively. Dilated fundus examination showed bilaterally scattered sub‐retinal, intraretinal and pre‐retinal haemorrhages in the posterior pole, with involvement of the right fovea. After the resolution of the haemorrhages, a fluoroangiography was performed which revealed delayed central retinal vein filling in the right eye. 2 months later, during follow‐up examination, visual acuity in the right eye was 0.7 and in the left eye 1.0. The haemorrhages have been absorbed bilaterally, leaving in the right eye a sub‐foveal photoreceptor and RPE disruption.Conclusions: Retinal haemorrhages can be observed after CPR. According to the literature, there have been reports of retinal haemorrhages in infants after CPR. Meanwhile, there is only one published case of an adult with associated comorbidities with this clinical presentation. The underlying pathophysiology of this clinical entity is still unclear, although a potential relationship between the increase in central venous pressure during CPR, and sequential retinal venous stasis is suspected.

Measuring intraoperative anesthetic parameters during hepatectomy with inferior vena cava clamping.

Uncontrollable bleeding remained problematic in anatomical hepatectomy exposing hepatic veins. Based on the inferior vena cava (IVC) anatomy, we attempted to analyze the hemodynamic and surgical effects of the combined IVC-partial clamp (PC) accompanied with the Trendelenburg position (TP). We prospectively assessed 26 consecutive patients who underwent anatomical hepatectomies exposing HV trunks between 2020 and 2023. Patients were divided into three groups: use of IVC-PC (group 1), no use of IVC-PC (group 2), and use of IVC-PC accompanied with TP (group 3). In 10 of 26 patients (38%), hepatic venous pressure was examined using transhepatic catheter insertion. IVC-PC was performed in 15 patients (58%). Operating time and procedures did not significantly differ between groups. A direct hemostatic effect on hepatic veins was evaluated in 60% and 70% of patients in groups 1 and 3, respectively. Group 1 showed significantly more unstable vital status and vasopressor use (p < 0.01). Blood or fluid transfusion and urinary output were similar between groups. Group 2 had a significantly lower baseline central venous pressure (CVP), while group 3 showed a significant increase in CVP in TP. CVP under IVC-PC seemed lower than under TP; however, not significantly. Hepatic venous pressure did not significantly differ between groups. Systolic arterial blood pressure significantly decreased via IVC-PC in group 1 and to a similar extent in group 3. Heart rate significantly increased during IVC-PC (p < 0.05). IVC-PC combined with the TP may be an alternative procedure to control intrahepatic venous bleeding during anatomical hepatectomy exposing hepatic venous trunks.

Are dynamic measurements of central venous pressure in Fontan circulation during exercise or volume loading superior to resting measurements?

Abstract Background: The main objective measure to assess the health of the Fontan circulation is the pressure measurement of the superior vena cava or pulmonary arteries. We reviewed the literature for benefits of measuring resting pressure in the Fontan circuit and explored whether dynamic measurement by volume loading or exercise has the potential to refine this diagnostic tool. Methods: PubMed was searched for articles showing a relationship between resting post-operative central venous pressure or pulmonary artery pressure and Fontan failure. Relationships between post-operative central venous pressure or pulmonary artery pressure and volume loading changes, such as during exercise or volume loading during cardiac catheterization, were also queried. Results: A total of 44 articles mentioned relationships between resting central venous pressure or pulmonary artery pressure and Fontan failure. Only 26 included an analysis between the variables and only seven of those articles found pressure to be predictive of Fontan failure. Ten articles examined the relationship between exercise or volume loading and outcomes and demonstrated a large individual variation of pressures under these dynamic conditions. Conclusions: Based on current literature, there is not a lot of strong evidence to show that elevated resting central venous pressure or pulmonary artery pressure is predictive of Fontan failure. Some individuals experience dramatic increases in central venous pressure or pulmonary artery pressure under increased loading conditions with exercise or bolus fluid infusion, while others experience increases closer to that of a healthy control population. Further studies are needed to examine whether more dynamic and continuous monitoring of systemic venous pressures might better predict outcomes in patients with Fontan circulation.

Right heart failure as a source of B-lines at lung ultrasound: prevalence and functional correlates

Abstract Background Lung ultrasound is part of the standard transthoracic examination and B-lines provide an index of extravascular lung water allowing to measure pulmonary congestion in left heart failure. However, pulmonary congestion can also appear as a consequence of right heart failure and it has been assumed that depends on the increase in central venous pressure increasing the resistance to lymphatic drainage. Aim of this study was to assess the prevalence of lung B-lines in a clinical model of pure right heart failure due to idiopathic pulmonary arterial hypertension (PAH) and its correlation with haemodynamic parameters. Methods All patients referred for suspicion of pulmonary hypertension in a single tertiary centre from January 2020 to December 2022 underwent a complete diagnostic work-up including echocardiography, lung ultrasound and right heart catheterization. The diagnosis of PAH was made following the current international recommendations. Pulmonary congestion was identified by lung ultrasound B-lines using an 8-site scan. Results The study enrolled 102 patients with PAH. Patients’ characteristics are shown in Table 1. The median lung B-lines were 3 [IQR: 1-5]. Results of univariate and multivariate analysis of B-lines predictors are shown in Table 1. Right atrial pressure (RAP), tricuspid annular plane excursion (TAPSE)/ Systolic pulmonary pressure (sPAP) ratio and pro hormone brain natriuretic peptide (proBNP) were independent predictors of B lines. Conclusion RAP, TAPSE/sPAP and proBNP were independent predictors of B lines in PAH patients according to the pathophysiological hypothesis that B-lines depends on the increase in central venous pressure increasing the resistance to lymphatic drainage.Table 1

Effect of Anesthesia Induction on Cardiac Hemodynamics in Patients Undergoing Durable Left Ventricular Assist Device Implantation: The EACH-LVAD Study.

Right ventricular (RV) dysfunction is common after left ventricular assist device (LVAD) implantation leading to clinical right heart failure (RHF) associated with worsened survival and quality of life. It is likely that intraoperative events such as anesthesia induction play a role in the development or unmasking of RV dysfunction in addition to known effects from hemodynamic changes that occur after LVAD implantation. The EACH-LVAD Study is a prospective, single-center, single-arm, observational cohort study of adult patients with advanced heart failure undergoing durable LVAD implantation with standard anesthesia induction. Intraoperative RV hemodynamics via central venous pressure, mean pulmonary artery pressure, pulmonary artery pulsatility index, and vasoactive-inotropic score (a simple weighted summation of standardized drug doses) and echocardiographic parameters (RV fractional area change, RV area in diastole, RV basal diameter, septum position, RV function, tricuspid regurgitation) were measured and compared at prespecified timepoints, including postinduction. Postoperative clinical RHF was determined based on published definitions. Forty-two patients receiving a first-time LVAD were included between September 2017 and March 2019. Propofol-based induction was used in 31 patients and etomidate-based induction in eight patients. A significant increase in central venous pressure (CVP; p < 0.001), mean pulmonary artery pressure (mPAP; p < 0.001), and vasoactive inotropic score (VIS; p < 0.001) with associated decrease in pulmonary artery pulsatility index (PAPi; p < 0.001) was observed. Right ventricular function worsened throughout. Right heart failure occurred in 70% of patients. Propofol-based induction was not associated with a higher risk of RHF (relative risk [RR], 1.01 [95% confidence interval {CI}, 0.64-1.61]). The EACH-LVAD study demonstrates an effect of anesthesia induction on worsened RV hemodynamics and echocardiographic changes which may have an effect on the development of RHF.

The case report of Abernethy malformation type Ib in an adult patient with pulmonary arterial hypertension

This clinical case illustrates the diagnosis of a rare congenital pathology – an adult patient with pulmonary arterial hypertension and Abernethy malformation type Ib.Clinical observation: Patient S., 45 years old, with pulmonary arterial hypertension, was admitted with complaints of shortness of breath during intense physical exertion. Based on the anamnesis morbi, the diagnosis of idiopathic pulmonary arterial hypertension has been verified since 2017. Results of comprehensive examination: functional status (six-minute walk test), NTpro-BNP level, chest x-ray, echocardiography, right heart catheterization were assessed during the hospitalization. According to these there were signs of the high pulmonary arterial hypertension with systolic pressure in the lung arteries 68-70 mm Hg, extension of the trunk, right and left branches of the pulmonary artery. In order to exclude objective evidence of cardiac dysfunction, portal hypertension, an abdominal ultrasound was performed. We didn’t obtaine the information about an increase in central venous pressure, the presence of signs of portal hypertension, such as ascites, increased pressure in the portal system. However, echo signs of congenital pathology were determined - Abernethy malformation type Ib: porto-caval shunt between the superior mesenteric vein and the inferior vena cava. According to multispiral computed tomography of abdominal organs with contrast: the superior mesenteric vein and splenic vein join to form a short extra-hepatic portal vein which drains into a systemic vein (inferior vena cava). Taking into account the results of risk stratification, the patient underwent an escalation of pathogenetic therapy for the treatment of pulmonary arterial hypertension, and dynamic monitoring was recommended.Conclusion: The presented clinical case is unique in terms of diagnosing a rare congenital pathology of the hepatic blood flow – Abernethy malformation type Ib in an adult patient with pulmonary arterial hypertension.

The haemodynamic effects of phenylephrine after cardiac surgery.

Phenylephrine increases systemic- and pulmonary resistances and therefore may increase blood pressures at the expense of blood flow. Cardio-pulmonary bypass alters vasoreactivity and many patients exhibit chronotropic insufficiency after cardiac surgery. We aimed to describe the haemodynamic effects of phenylephrine infusion after cardiac surgery. Patients in steady state after low-risk cardiac surgery received incremental infusion rates of phenylephrine up to 1.0 μg/kg/min with the aim of increasing systemic mean arterial blood pressure 20 mmHg. Invasive haemodynamic parameters, including pulmonary wedge pressures, were captured along with echocardiographic measures of biventricular function before, during phenylephrine infusion at target systemic blood pressure, and 20 min after phenylephrine discontinuation. Thirty patients were included. Phenylephrine increased mean arterial pressure increased from 78 (±9) mmHg to 98 (±10) mmHg with phenylephrine infusion. Also, pulmonary blood pressure as well as systemic- and pulmonary resistances increased. The ratio between systemic- and pulmonary artery resistances did not change statistically significantly (p = .59). Median cardiac output was 4.35 (interquartile range [IQR] 3.6-5.4) L/min at baseline and increased significantly with phenylephrine infusion (median Δcardiac output was 0.25 [IQR 0.1-0.6] L/min) (p = .012). Pulmonary artery wedge pressure increased from 10.2 (±3.0) mmHg to 11.9 (±3.4) mmHg (p < .001). This was accompanied by significant increases in central venous pressure. Phenylephrine infusion increased left ventricular end-diastolic volume from 105 (±46) mL to 119 (±44) mL (p < .001). All results of phenylephrine infusion were reversed with discontinuation. In haemodynamically stable patients after cardiac surgery, phenylephrine increased PVR and SVR, but did not change the PVR/SVR ratio. Phenylephrine increased biventricular filling pressures and left ventricular end-diastolic area. Consequently, CO increased as ejection fraction was maintained. These findings do not discourage the use of phenylephrine after low-risk cardiac surgery. clinicaltrial.gov (identifier NCT04419662).

Diagnostic value of an increase in central venous pressure during SBT for prediction of weaning failure in mechanically ventilated patients: A cross-sectional study.

Timely and successful extubation is an essential step forward in clinical practice to minimize complications of mechanical ventilation and unsuccessful weaning processes. Thus, research into predictive factors of weaning outcome to optimize spontaneous breathing trial (SBT) precision before extubation is critical in intensive care practices. In this study, we aimed to investigate the predictive factors of the weaning outcome before and during SBT in mechanically ventilated patients. In this cross-sectional study, 159 mechanically ventilated patients who were eligible for SBT were enrolled. Of these patients, 140 had successful extubation, whereas the remainder failed. Each patient's PaCO2 and PaO2 levels, respiratory rate (RR), SpO2, mean arterial pressure (MAP), heart rate (HR), and central venous pressure (CVP) values at the start of SBT, 3 min later, and at the end of SBT were measured. These values, along with the patients'clinical characteristics, were then investigated to determine if there was any correlation between these variables and the weaning outcome. Our analysis revealed that increase in CVP, independent of hemoglobin (Hb) concentration, PaO2, SpO2, duration of mechanical ventilation (MV), length of intensive care unit (ICU) stay, and SBT process, as well as underlying disease, was positively correlated with extubation/weaning failure. While age, gender, vital signs (MAP, RR, and HR), sequential organ failure assessment (SOFA), and acute physiology and chronic health evaluation (APACHE) scores had no significant correlation with patients'extubation outcomes. According to our findings, integrating CVP assessment into SBT besides routine indices measurement and monitoring can be considered for the prediction of weaning outcome in critically ill mechanically ventilated patients.

Comparing the associations of central venous pressure and pulmonary artery pulsatility index with postoperative renal injury.

ObjectiveCardiac surgery-associated acute kidney injury (CS-AKI) is associated with significant morbidity and mortality. We investigated the association of postoperative central venous pressure (CVP) and pulmonary artery pulsatility index (PAPi) with the development of CS-AKI.MethodsThis was a single-center, retrospective cohort study of patients undergoing cardiac surgery. CVP and PAPi were acquired hourly postoperatively and averaged for up to 48 h. PAPi was calculated as [(Pulmonary Artery Systolic Pressure–Pulmonary Artery Diastolic Pressure) / CVP]. The primary aim was CS-AKI. Secondary aims were need for renal replacement therapy (RRT), hospital and 30-day mortality, total ventilator and intensive care unit hours, and hospital length of stay. Logistic regression was used to calculate odds of development of renal injury and need for RRT.ResultsOne thousand two hundred eighty-eight patients were included. The average postoperative CVP was 10.3 mmHg and average postoperative PAPi was 2.01. Patients who developed CS-AKI (n = 384) had lower PAPi (1.79 vs. 2.11, p < 0.01) and higher CVP (11.5 vs. 9.7 mmHg, p < 0.01) than those who did not. Lower PAPi and higher CVP were also associated with each secondary aim. A standardized unit decrease in PAPi was associated with increased odds of CS-AKI (OR 1.39, p < 0.01) while each unit increase in CVP was associated with both increased odds of CS-AKI (OR 1.56, p < 0.01) and postoperative RRT (OR 1.49, p = 0.02).ConclusionsBoth lower PAPi and higher CVP values postoperatively were associated with the development of CS-AKI but only higher CVP was associated with postoperative RRT use. When differences in values are standardized, CVP may be more associated with development of CS-AKI when compared to PAPi.

Cardiac response to changes in central venous sonomorphology: Mechanism of impaired heart relaxation in patients with varicose veins of lower extremities.

This study examines the interactions between central venous and cardiac sonomorphologies to explain the mechanism of impaired heart relaxation in patients with varicose veins of lower extremities. Part 1: We performed retrospective analysis of influences of inferior vena cava (IVC) diameters on tricuspid and mitral inflow and annular velocities in 64 patients with primary varicose veins. Part 2: We compared IVC diameters and IVC collapsibility index (IVC CI) in patients with varicose veins with normal values. We found a significant positive influence of an increase in maximal expiratory and minimal inspiratory IVC diameters on mitral and tricuspid early annular velocities or e'-waves (p-values < .008), inflow velocities or E-waves (p-values < .05) and early to late inflow E/A ratios (p-values < .01). Less influenced by the changes in venous biometry (p-values > .05) were late mitral and tricuspid inflow, annular and systolic velocities (A-, a'-, s-waves).Expiratory and inspiratory diameters in patients with varicose veins were significantly smaller (p-values < .05 expiratory; < .0001 inspiratory), and IVC CI was significantly higher (p-values < .0001) than the normal values. Chronic venous disease impairs the function and the morphology of the entire inferior caval system and the heart. Impaired relaxation of the heart in patients with varicose veins is the result of two factors: (1) impaired venous return resulting in the low central venous pressure and the low early diastolic cardiac inflow; (2) structural changes in the heart resulting in the compensatory increased late diastolic cardiac inflow. Increase in central venous pressure (IVC diameters) and early diastolic cardiac inflow (E-waves), accompanied by unchanged myocardial response (e'-wave) can serve as marker for return to normal physiology.

Venous waveform analysis detects acute right ventricular failure in a rat respiratory arrest model.

Peripheral intravenous analysis (PIVA) has been shown to be more sensitive than central venous pressure (CVP) for detecting hemorrhage and volume overload. We hypothesized that PIVA is superior to CVP for detecting right ventricular (RV) failure in a rat model of respiratory arrest. Eight Wistar rats were studied in accordance with the ARRIVE guidelines. CVP, mean arterial pressure (MAP), and PIVA were recorded. Respiratory arrest was achieved with IV Rocuronium. PIVA utilizes Fourier transform to quantify the amplitude of the peripheral venous waveform, expressed as the "f1 amplitude". RV diameter was measured with transthoracic echocardiography. RV diameter increased from 0.34 to 0.54 cm during arrest, p = 0.001, and returned to 0.33 cm post arrest, p = 0.97. There was an increase in f1 amplitude from 0.07 to 0.38 mmHg, p = 0.01 and returned to 0.08 mmHg, p = 1.0. MAP decreased from 119 to 67 mmHg, p = 0.004 and returned to 136 mmHg, p = 0.50. There was no significant increase in CVP from 9.3 mmHg at baseline to 10.5 mmHg during respiratory arrest, p = 0.91, and recovery to 8.6 mmHg, p = 0.81. This study highlights the utility of PIVA to detect RV failure in small-caliber vessels, comparable to peripheral veins in the human pediatric population. Right ventricular failure remains a diagnostic challenge, particularly in pediatric patients with small vessel sizes limiting invasive intravascular monitor use. Intravenous analysis has shown promise in detecting hypovolemia and volume overload. Intravenous analysis successfully detects right ventricular failure in a rat respiratory arrest model. Intravenous analysis showed utility despite utilizing small peripheral venous access and therefore may be applicable to a pediatric population. Intravenous analysis may be helpful in differentiating various types of shock.

Effect of positive end-expiratory pressure on central venous pressure in the closed and open thorax

Objective. The magnitude and mechanism of the rise of central venous pressure (CVP) after positive end-expiratory pressure (PEEP) among patients with cardiac disease is poorly understood. Therefore, the study aimed to compare the magnitude of change in CVP after PEEP in patients with TR (tricuspid regurgitation), high CVP, and high PCWP (pulmonary capillary wedge pressure) and in those with no TR, low CVP, and low PCWP. Additionally, we hypothesized that PEEP in the open thorax would also lead to a rise in CVP. Approach. This prospective, quasi-experimental study was conducted in patients undergoing cardiac surgery. Three consecutive readings of variables were obtained at 1 min intervals after PEEP (5 and 10 cm H2O) application in the closed and open thorax. Patients were stratified a priori into low CVP (<10 cm H2O) and high CVP (≥10 cm H2O), no TR and TR, and low PCWP (<15 mm Hg) and high PCWP (≥15 mm Hg) in the closed and open thorax. Main Results. Sixty-two patients were eligible for final analysis. The mean difference (MD) in ΔCVP (CVP10 cm H2O of PEEP—CVP zero end-expiratory pressure) was 2.33 ± 1.13 (95% CI, 2.04–2.62, P = 0.000) and 1.02 ± 0.77 (95% CI, 0.82–1.22, P = 0.000) in the closed and open thorax, respectively. The increase in CVP was higher among patients who had a lower CVP (2.64 ± 0.9 mm Hg versus 1.45 ± 1.17 mm Hg; p=0.000), in patients without TR (2.64 ± 0.97 mm Hg versus 2.14 ± 1.2 mm Hg, p=0.09) and in patients with a lower PCWP (2.4 ± 0.9 mm Hg versus 2.3 ± 1.4 mm Hg, p=0.67) at 10 cm H2O PEEP in the closed thorax. Significance. The rise in CVP was higher among patients without TR, low CVP, and low PCWP. Zero intrathoracic pressure in the open thorax did not abolish the effect of PEEP on CVP rise altogether.

Changes of thoracic duct flow and morphology in an animal model of elevated central venous pressure

Objective: Investigation of lymph fluid dynamics in thoracic duct during central venous pressure elevation. Background: Lymphatic flow is affected by elevated central venous pressure (CVP) in congestive heart failure. The changes of thoracic duct (TD) lymph flow have not been studied chronically in the setting of elevated CVP. This study is to investigate fluid dynamics and remodeling of the TD in the elevated CVP animal model. Methods: A flow probe was implanted on the swine TD (n = 6) and tricuspid regurgitation (TR) was created by cutting tricuspid chordae percutaneously. Six swine were used as control group animals. The TD flow was measured for 2 weeks (baseline) before TR and 4 weeks postop-TR surgery. Arterial pressure and CVP were measured. The pressure and flow in the TD were measured percutaneously. Histological and morphological analyses were performed. Results: TR resulted in an increase in CVP from 4.2 ± 2.6 to 10.1 ± 4.3 mmHg (p < 0.05). The lymph flow in the TD increased from 0.78 ± 1.06 before TR to 8.8 ± 4.8 ml/min (p < 0.05) 2 days post-TR and remained plateau for 4 weeks, i.e., the TD flow remained approximately 8–11 fold its baseline. Compared to the 8.1 ± 3.2 mmHg control group, the TD average pressures at the lymphovenous junction increased to 14.6 ± 5.7 mmHg in the TR group (p < 0.05). The TD diameter and wall thickness increased from 3.35 ± 0.37 mm and 0.06 ± 0.01 mm in control to 4.32 ± 0.57 mm and 0.26 ± 0.02 mm (p < 0.05) in the TR group, respectively. Conclusion: The elevated CVP results in a significant increase in TD flow and pressure which causes the TD’s outward remodeling and thickening. Our study implicates that the outward remodeling may result in the TD valve incompetence due to failure coaptation of leaflets.

Influence of the Trendelenburg position and carboxyperitoneum on cerebral tissue oximetry values

Background. Cerebral tissue oximetry (rSO2) can be used to assess cerebral circulation. Cerebral tissue oximetry studies have been performed in the Trendelenburg position (30º), but data for 45 o are not available.Objective. To study the effect of the Trendelenburg position (45°) under carboxyperitoneum conditions on rSO2 and hemodynamic parameters.Design and methods. A single-center, prospective, descriptive study was conducted among patients (n = 30) who underwent robot-assisted laparoscopic prostatectomy. We measured rSO2 on the left and right, central venous pressure (CVP), mean arterial pressure (MAP), venous saturation at points: T1 — after induction of anesthesia and start of measurements; T2 — 5 minutes after positioning the patient in the Trendelenburg position of 45o; T3 — 15 minutes; T4 — 30 minutes; T5 — after returning to a horizontal position. Cerebral perfusion was assessed using cerebral perfusion pressure (CPP).Results. rSO2 on the right and left at points T2, T3 and T5 significantly exceeded T1. There was a significant increase in BP mean at T2 and T3, as well as a significant increase in CVP at T2, T3 and T4 compared to T1. The CPP significantly decreased compared to T1 at points T3, T4 and T5.Conclusions. The Trendelenburg position with a tilt angle of 45º in combination with carboxyperitoneum is accompanied by an increase in rSO2, blood pressure and CVP.

Effective Sphygmomanometer Based Non-invasive Central Venous Pressure Measurement In Hospitalized Heart Failure Patients

<h3>Background</h3> : Central venous pressure (CVP) estimation is vital in treating patients with heart failure (HF) exacerbation, with the measurement being routinely performed via physical examinations, which can frequently be difficult to obtain. This difficulty is further compounded in the age of expanding telemedicine, limiting the physicians' ability to care for HF patients remotely. A simple and accurate non-invasive measurement of CVP is needed. Recently a non-invasive device using a sphygmomanometer pump and oscillometric method to measure enclosed-zone CVP (ezCVP^TM) was developed (Nihon Kohden, Corp., Japan) and was found to accurately predict invasively measured CVP. However, whether ezCVP correlates with the clinical outcome or can be used to guide clinical management is unknown. We conducted a pilot study to assess its clinical utility of this novel technology in managing hospitalized patients with a primary diagnosis of HF exacerbation. <h3>Methods</h3> : Patients admitted to the HF inpatient service were enrolled. Both HF with reduced ejection fraction and preserved ejection fraction were included. Major exclusion criteria included patients in atrial fibrillation, on inotrope, on renal replacement therapy, or have severe tricuspid valve regurgitation. Daily measurement of ezCVP was performed and values were converted to CVP_NI (CVP non-invasive) as previously described. The treatment team was blinded from the CVP_NI values. We correlated the CVP_NI values with the hospital course and parameters such as weight and renal function. Finally, we compared the length of hospital stay between patients who had high or low admission CVP_NI values. <h3>Results</h3> : 22 patients were enrolled in this pilot study, and overall the patients' CVP_NI value decreased as they received diuresis. 8 patients had CVP_NI below the detection limit of ∼2 mmHg (shown as "0") upon admission and remained unchanged. The CVP_NI values upon discharge were overall low (mean +/- SD: 5 +/- 7, median 0). 3 patients had an increase in CVP_NI at discharge, 2 of them had worsening HF and were transitioned to comfort care and therefore the increase in CVP_NI was clinically consistent. The patients with low CVP_NI values upon admission had a shorter length of hospital stay compared to patients with higher CVP_NI values. <h3>Conclusion</h3> : CVP_NI correlated with the clinical course of HF patients receiving diuresis. Admission CVP_NI value was also predictive in overall length of stay in the hospital. This pilot study showed the feasibility and utility of using CVP_NI measurement as part of inpatient HF care. A larger study to confirm these findings is needed.

Cardiorespiratory impact of intrathoracic pressure overshoot during artificial carbon dioxide pneumothorax: a randomized controlled study

BackgroundThe aim of this study is to evaluate cardiovascular and respiratory effects of intrathoracic pressure overshoot (higher than insufflation pressure) in patients who underwent thoracoscopic esophagectomy procedures with carbon dioxide (CO2) pneumothorax.MethodsThis prospective research included 200 patients who were scheduled for esophagectomy from August 2016 to July 2020. The patients were randomly divided into the Stryker insufflator (STR) group and the Storz insufflator (STO) group. We recorded the changes of intrathoracic pressure, peak airway pressure, blood pressure, heart rate and central venous pressure (CVP) during artificial pneumothorax. The differences in blood gas analysis, the administration of vasopressors and the recovery time were compared between the two groups.ResultsWe found that during the artificial pneumothorax, intrathoracic pressure overshoot occurred in both the STR group (8.9 mmHg, 38 times per hour) and the STO group (9.8 mmHg, 32 times per hour). The recorded maximum intrathoracic pressures were up to 58 mmHg in the STR group and 51 mmHg in the STO group. The average duration of intrathoracic pressure overshoot was significantly longer in the STR group (5.3 ± 0.86 s) vs. the STO group (1.2 ± 0.31 s, P < 0.01). During intrathoracic pressure overshoot, a greater reduction in systolic blood pressure (SBP) (5.6 mmHg vs. 1.1 mmHg, P < 0.01), a higher elevation in airway peak pressure (4.8 ± 1.17 cmH2O vs. 0.9 ± 0.41 cmH2O, P < 0.01), and a larger increase in CVP (8.2 ± 2.86 cmH2O vs. 4.9 ± 2.35 cmH2O, P < 0.01) were observed in the STR group than in the STO group. Vasopressors were also applied more frequently in the STR group than in the STO group (68% vs. 43%, P < 0.01). The reduction of SBP caused by thoracic pressure overshoot was significantly correlated with the duration of overshoot (R = 0.76). No obvious correlation was found between the SBP reduction and the maximum pressure overshoot.ConclusionsIntrathoracic pressure overshoot can occur during thoracoscopic surgery with artificial CO2 pneumothorax and may lead to cardiovascular adverse effects which highly depends on the duration of the pressure overshoot.Trial registrationClinicaltrials.gov (NCT02330536; December 24, 2014).

A novel sphygmomanometer for central venous pressure assessment during stress echocardiography

Abstract Funding Acknowledgements Type of funding sources: None. OnBehalf StressEcho 2030 study group Background. Central venous pressure (CVP) is important in the hemodynamic phenotyping of failing heart, and the usual invasive assessment can be surrogated by a sphygmomanometer for venous pressure (SVEN) which has been recently prototyped and validated. Aim To assess the technical success rate and correlates of CVP measurements by SVEN during stress echocardiography (SE) Methods We evaluated 22 consecutive patients (age 66 ±11 years, 15 men, ejection fraction 60 ±6%) referred for clinically-driven dipyridamole (n = 20, for chest pain) or treadmill (n = 2, for dyspnea) SE with ABCDE protocol (score range from 0= all steps normal, to 5= all steps abnormal). Step A assesses regional wall motion abnormalities (RWMA); step B, B-lines (diastolic function); step C, left ventricular contractile reserve based on force; step D, coronary flow velocity reserve (CFVR) in left anterior descending artery; step E, heart rate reserve (HRR). In each patient, the usual setting of echocardiographic, electrocardiographic and arterial blood pressure monitoring was integrated with CVP measurement by SVEN (right arm, contralateral to the arterial sphygmomanometer arm) with personalized cuff sizes. SVEN measurements of CVP were obtained at rest and peak stress. Results. SVEN preparation and automated analysis required &amp;lt; 5 minutes for positioning, inflation-deflation, acquisition and off-line reading for single measurement. SVEN success rate was 22/22 (100%). CVP did not change during SE (rest = 2.4 ± 0.5 vs stress= 3.7 ± 0.8 mmHg, p = 0.106). Resting CVP was correlated inversely to ejection fraction at rest (r=-0.489, p = 0.021) and at peak stress (r=-0.545, p = 0.001), CFVR (r=-0.505, p = 0.023), HRR (r=-0.503, p = 0.017) and directly to RWMA (r = 0.431, p = 0.045), B-lines at peak stress (r= 0.626, p = 0.002) and left atrial volume index at rest (r= 0.552, p =0.012) and at peak stress (r = 0.648, p = 0.002). CVP was significantly higher in patients with B-Lines at peak stress (Figure). ABCDE score was directly related to CVP (r = 0.560, p = 0.007). Conclusion. SVEN assessment is feasible at rest and during stress with extremely high success rate and only minimal increase in preparation and analysis time. Changes observed are consistent with the expected hemodynamic profile, with CVP increase associated with more B-lines (a sign of pulmonary congestion and elevated pulmonary capillary wedge pressure) and larger left atrium (an integrated barometer of left ventricular end-diastolic pressure). Abstract Figure.