Invasive Central Venous Pressure Research Articles

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.

Organ perfusion pressure at admission and clinical outcomes in patients hospitalized for acute heart failure

Abstract Background Hypoperfusion portends adverse outcomes in acute heart failure (AHF). The gradient between end-organ inflow and outflow pressures may more closely reflect hypoperfusion than mean arterial pressure (MAP) alone. Purpose To investigate organ perfusion pressure (OPP), calculated as MAP minus central venous pressure (CVP), as a prognostic marker in AHF. Methods The SNIP-AHF study was a multicenter retrospective cohort study of 200 consecutive patients hospitalized for AHF treated with sodium nitroprusside. Only patients with both MAP and invasive CVP data available from the SNIP-AHF cohort were included. The primary endpoint was to assess OPP as a predictor of worsening heart failure (WHF) at 48 hours. Results 146 patients were included (mean age: 61.1±13.5 years, 32 [21.9%] females; mean left ventricular ejection fraction: 23.8%±11.4%, mean MAP: 80.2±13.2 mmHg, mean CVP: 14.0±6.1 mmHg). WHF occurred in 14 (9.6%) patients. At multivariable models including hemodynamic variables (OPP, shock index, MAP and CVP), OPP at admission was the best predictor of WHF at 48 hours (OR 0.91 [95%CI 0.86-0.96], p-value = 0.001) with an optimal cut-off value of 67.5 mmHg (specificity 47.3%, sensitivity 100%, AUC 0.784±0.054 [p-value&amp;lt;0.001]). In a multivariable model including univariable significant parameters available at first beside assessment, namely New York Heart Association functional class, OPP, shock index, MAP and left ventricular end-diastolic diameter, OPP significantly predicted WHF at 48 hours (OR 0.82 [95%CI 0.68-0.98], p-value=0.027). Conclusion In this retrospective analysis on patients hospitalized for AHF treated with sodium nitroprusside, on-admission OPP significantly predicted WHF at 48 hours with high sensitivity.OPP in acute heart failureMultivariable analysis on WHF

Organ perfusion pressure at admission and clinical outcomes in patients hospitalized for acute heart failure.

Hypoperfusion portends adverse outcomes in acute heart failure (AHF). The gradient between end-organ inflow and outflow pressures may more closely reflect hypoperfusion than mean arterial pressure (MAP) alone. The aim of this study was to investigate organ perfusion pressure (OPP), calculated as MAP minus central venous pressure (CVP), as a prognostic marker in AHF. The Sodium NItroPrusside Treatment in Acute Heart Failure (SNIP)-AHF study was a multicentre retrospective cohort study of 200 consecutive patients hospitalized for AHF treated with sodium nitroprusside. Only patients with both MAP and invasive CVP data available from the SNIP-AHF cohort were included in this analysis. The primary endpoint was to assess OPP as a predictor of worsening heart failure (WHF), defined as the worsening of signs and symptoms of heart failure leading to intensification of therapy at 48 h. One hundred and forty-six patients fulfilling the inclusion criteria were included [mean age: 61.1 ± 13.5 years, 32 (21.9%) females; mean body mass index: 26.2 ± 11.7 kg/m2; mean left ventricular ejection fraction: 23.8%±11.4%, mean MAP: 80.2 ± 13.2 mmHg, and mean CVP: 14.0 ± 6.1 mmHg]. WHF occurred in 14 (9.6%) patients. At multivariable models including hemodynamic variables (OPP, shock index, and CVP), OPP at admission was the best predictor of WHF at 48 h [OR 0.91 (95% confidence interval 0.86-0.96), P-value = 0.001] with an optimal cut-off value of 67.5 mmHg (specificity 47.3%, sensitivity 100%, and AUC 0.784 ± 0.054). In multivariable models, including univariable significant parameters available at first bedside assessment, namely New York Heart Association functional class, OPP, shock index, CVP, and left ventricular end-diastolic diameter, OPP consistently and significantly predicted WHF at 48 h. In this retrospective analysis on patients hospitalized for AHF treated with sodium nitroprusside, on-admission OPP significantly predicted WHF at 48 h with high sensitivity.

Abstract 15532: Pressure Measurement From a Peripheral Iv Correlates Well With Invasive Central Venous Pressure Measurement

Introduction: Despite its importance in cardiac patients, accurate central venous pressure (CVP) estimation remains a challenge. Noninvasive methods, such as jugular venous pressure measurement, are highly dependent on examiner experience, and the gold-standard invasive methods require procedures that carry risk of complication. Recent studies suggest that pressure measurement directly from a patient’s peripheral intravenous (IV) catheter, termed peripheral venous pressure (PVP), appears promising as an accurate and noninvasive method for CVP estimation. Methods: To be included in the study, patients were either receiving right heart catheterization (RHC) or had an existing pulmonary artery catheter (PAC) in place. CVP was measured using standard technique either during RHC or at bedside from the PAC. The same pressure tubing was then connecting to the patient’s existing IV, regardless of the location or catheter gauge, for measurement of the PVP. Results: Seventeen patients were prospectively enrolled. The majority (70.6%) had their CVP and PVP measured during RHC. In the overall cohort, 35.3% were on mechanical circulatory support, and 29.4% were on inotropes at the time of measurement. CVP and PVP measurements were significantly correlated with one another (Pearson’s r = 0.73, p &lt; 0.001; Figure 1A). Sensitivity analysis was performed to exclude one notable outlier, which strengthened the correlation (Pearson’s r = 0.91, p &lt; 0.001; Figure 1B). Conclusions: This data suggests that PVP is a promising and simple method for the noninvasive estimation of CVP.

Ultrasound imaging and central venous pressure in spontaneously breathing patients: a comparison of ultrasound-based measures of internal jugular vein and inferior vena cava.

Ultrasound evaluation of inferior vena cava and internal jugular vein dia-meters predicts the intravascular volume status in critical patients. The aim of the present study was to determine which ultrasound-derived index is most strongly associated with central venous pressure (CVP). Furthermore, we determined the utility of selected variables in predicting low volume status (CVP < 8 mmHg). All patients underwent a transthoracic echocardiogram, vascular ultrasound examination, invasive central venous pressure, and intra-abdominal pressure determination. The following indexes were calculated: inferior vena cava diameter, internal jugular vein maximum diameter, collapsibility index, and internal jugular vein ratio. 41 spontaneously breathing patients were recruited. Central venous pressure significantly correlated with inferior vena cava diameter ( r = 0.35, P = 0.02), internal jugular vein ratio ( r = 0.35, P = 0.03), and internal jugular vein maximum diameter ( r = 0.58, P < 0.001). The inferior vena cava collapsibility index did not show any association. The areas under the receiver operating characteristic curves to discriminate a low central venous pressure (< 8 mmHg) were the following: internal jugular vein diameter 0.80 (95% CI: 0.63-0.90); inferior vena cava diameter 0.66 (95% CI: 0.49-0.80); and internal jugular vein ratio 0.68 (95% CI: 0.51-0.82). The internal jugular vein diameter, the internal jugular vein ratio, and the inferior vena cava diameter showed a significant correlation with central venous pressure. In particular, the internal jugular vein diameter showed good accuracy in predicting a low central venous pressure.

COMPARISON OF NONINVASIVE CENTRAL VENOUS PRESSURE MEASUREMENT METHODS: INTERNAL JUGULAR VEIN VERSUS VENA CAVA INFERIOR

Objective&#x0D; Central venous pressure measurement is an effective&#x0D; method to detect the volume status of the patients.&#x0D; However, life-threatening complications such as&#x0D; pneumothorax may occur. We assume that ultrasonographic&#x0D; measurements may be used as a surrogate&#x0D; of invasive central venous pressure.&#x0D; Materials and Methods&#x0D; Our study has been conducted between January&#x0D; 2015-January 2016 on 81 patients who were over&#x0D; the age of 18 and to whom a central venous catheter&#x0D; has been placed in the internal jugular vein (IJV)&#x0D; in our Emergency Intensive Care Unit. The height of&#x0D; the blood column in the internal jugular vein, internal&#x0D; jugular vein collapsibility index (IJV-CI) and the caval&#x0D; index (CI) of vena cava inferior have been measured&#x0D; by ultrasound. Then, invasive central venous pressure&#x0D; (CVP) has been measured and the patients were&#x0D; separated into two groups as low CVP and normal&#x0D; CVP groups and statistically significance was sought&#x0D; between groups in regard of these three methods.&#x0D; Results&#x0D; The mean age was 68.58±13.33 years. Fifty-four of&#x0D; the patients (66.6%) were male. Forty-six patients&#x0D; (56.8%) were mechanically ventilated. Low CVP&#x0D; group consisted of 62 patients (76.5%). Mean invasive&#x0D; CVP was 4.83±4.26 mmHg. There were significant&#x0D; correlations between IJV-CI and invasive CVP along&#x0D; with the CI (r=-0.267, p=0.016 and r=0.319, p=0.04,&#x0D; respectively), IJV height method and CI as well as&#x0D; invasive CVP measurement (r=-0.231, p=0.03 and&#x0D; r=0.357, p=0.01, respectively). The CI did not yield&#x0D; any correlation between invasive CVP measurement&#x0D; (r=-0.010, p=0.368).&#x0D; Conclusion&#x0D; Noninvasive central venous pressure measurement&#x0D; methods may be used as a surrogate for invasive&#x0D; central venous pressure levels. The IJV-CI may be&#x0D; a useful tool to estimate CVP. Measurements of IJV&#x0D; yields better results than the measurements from&#x0D; vena cava inferior (VCI) especially in volume depleted&#x0D; patients.

Optical Hemodynamic Imaging of Jugular Venous Dynamics During Altered Central Venous Pressure.

An optical imaging system is proposed for quantitatively assessing jugular venous response to altered central venous pressure. The proposed system assesses sub-surface optical absorption changes from jugular venous waveforms with a spatial calibration procedure to normalize incident tissue illumination. Widefield frames of the right lateral neck were captured and calibrated using a novel flexible surface calibration method. A hemodynamic optical model was derived to quantify jugular venous optical attenuation (JVA) signals, and generate a spatial jugular venous pulsatility map. JVA was assessed in three cardiovascular protocols that altered central venous pressure: acute central hypovolemia (lower body negative pressure), venous congestion (head-down tilt), and impaired cardiac filling (Valsalva maneuver). JVA waveforms exhibited biphasic wave properties consistent with jugular venous pulse dynamics when time-aligned with an electrocardiogram. JVA correlated strongly (median, interquartile range) with invasive central venous pressure during graded central hypovolemia (r=0.85, [0.72, 0.95]), graded venous congestion (r=0.94, [0.84, 0.99]), and impaired cardiac filling (r=0.94, [0.85, 0.99]). Reduced JVA during graded acute hypovolemia was strongly correlated with reductions in stroke volume (SV) (r=0.85, [0.76, 0.92]) from baseline (SV: 79 ± 15mL, JVA: 0.56 ± 0.10a.u.) to -40mmHg suction (SV: 59 ± 18mL, JVA: 0.47 ± 0.05a.u.; p 0.01). The proposed non-contact optical imaging system demonstrated jugular venous dynamics consistent with invasive central venous monitoring during three protocols that altered central venous pressure. This system provides non-invasive monitoring of pressure-induced jugular venous dynamics in clinically relevant conditions where catheterization is traditionally required, enabling monitoring in non-surgical environments.

P2473Non-invasive assessment of central venous pressure in heart failure: comparing three-dimensional echocardiography and Swan-Ganz catheter

Abstract Background Assessing hemodynamics, in particular central venous pressure (CVP) is essential in heart failure diagnostics, leading individual therapy. Hereby, invasive measurement through Swan-Ganz right heart catheterization (RHC) is considered gold standard for patient evaluation, but catheterization implies risks of invasiveness including bleeding, infection, vessel and nerve injury, as well as patient discomfort. Non-invasive methods are warranted, but no alternative technique is validated yet. Two-dimensional echocardiography (2DE) is believed to be uncertain in this approach as vena cava often shows ellipse-shapes. Therefore, this study sought to investigate standardized and breathing corrected three-dimensional inferior vena cava echocardiography (3DE) to directly compare CVP with right heart catheterization. Methods and results We prospectively included 100 consecutive heart failure patients in this study (mean age 53±12 years, body mass index 27±5, New York Heart Association functional class 2.3±0.6, left ventricular ejection fraction 34.1±12.8%, brain natriuretic peptide 658.13±974.03, 76% male), all underwent Swan-Ganz right-heart catheterization and immediately both 2DE and 3DE (Philips EPIQ 7G) of inferior vena cava. From two-dimensional data the diameter of IVC was measured perpendicularly in long and short-axis. From 3DE data a cross-sectional image of IVC was reconstructed for both vertical and horizontal diameters of IVC as well as the area of IVC. Established 2DE images revealed mean vena cava sizes of 15.9±5.9 mm, while standardized cross-sectional breathing corrected 3DE images showed diameters of 19.8±7.8 mm in longitudinal axis and 15.74±7.8 in short axis. RHC mean CVP was 9.00±5.4 mmHg and correlation of CVP and 2DE measurements failed adequate correlation (2DE 95% CI 0.19–1.61; r=0.25; p=0.312). However, 3DE axis ratio assessment correlated well with invasive CVP and showed reproducible results (3DE 95% CI 0.26–0.69; r=0.89; p&lt;0.01). This resulted for a CVP cut point of 10 mmHg in a 89% true negative and 50% true positive correct detection. Conclusions Standardized 3DE correlates well with invasive CVP while established 2DE usual care assessment does not show reliable CVP correlation. 3DE CVP assessment may represent a more feasible and easily applicable method for CVP measurement, including absence for risks of right heart catheterization. Further studies are ongoing to validate these findings in the future.

Bedside hand vein inspection for noninvasive central venous pressure assessment

Rapid estimates of the central venous pressure (CVP) can be helpful to administer early fluid therapy or to manage cardiac preload in intensive care units, operating rooms or emergency rooms in order to start and monitor an adequate medical therapy. Invasive CVP measurements have inherent and non-negligible complication rates as well as great expenditures. Several noninvasive methods of CVP measurements, like ultrasound-guided techniques, are available, but require trained skills and special equipment which might not be at hand in all situations.Our purpose was to evaluate the feasibility and accuracy of CVP estimates assessed upon the height of hand veins collapse (HVC) using invasively measured CVP as the gold standard.The HVC was determined by slowly lifting the patient's hand while watching the dorsal hand veins to collapse. The vertical distance from the dorsal hand to a transducer air zero port was noted and converted to mmHg. The observer was blinded to the simultaneously measured CVP values, which were categorized as low (<7 mmHg), normal (7–12 mmHg) and high (>12 mmHg).Measurements were performed in 82 patients who had a median [IQR] age of 67 [60;74]. Median CVP was 12 [8;15] mmHg and the median absolute difference between the measured HVC and CVP was 4 [2;7] mmHg. The Spearman correlation coefficient between CVP and HVC was 0.55, 95%-CI [0.35;0.69]. Overall CVP categorization was correct in 45% of the cases. HVC had a sensitivity of 92% for a low CVP with a negative predictive value of 98%. A high HVC had a sensitivity of 29% but a high specificity of 94% for a high CVP.The overall performance of observing the hand vein collapse to estimate CVP was only moderate in the intensive care setting. However, the median difference to the CVP was low and HVC identifies a low CVP with a high sensitivity and excellent negative predictive value.

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.

Reassessment of the Accuracy of Cardiac Doppler Pulmonary Artery Pressure Measurements in Ventilated ICU Patients: A Simultaneous Doppler-Catheterization Study*

Doppler echocardiography is a well-recognized technique for the noninvasive evaluation of pulmonary artery pressure; however, little information is available concerning patients receiving mechanical ventilation. Furthermore, recent studies have debatable results regarding the relevance of this technique to assess pulmonary artery pressure. The aim of our study was to reassess the accuracy of Doppler echocardiography to evaluate pulmonary artery pressure and to predict pulmonary hypertension. Prospective observational study. Amiens ICU, France. ICU patients receiving mechanical ventilation. In 40 patients, we simultaneously recorded Doppler echocardiography variables (including tricuspid regurgitation and pulmonary regurgitation) and invasive central venous pressure, systolic pulmonary artery pressure, diastolic pulmonary artery pressure, and mean pulmonary artery pressure. Systolic pulmonary artery pressure assessed from the tricuspid regurgitation derived maximal pressure gradient added to the central venous pressure demonstrated the best correlation with the invasive systolic pulmonary artery pressure (r = 0.87) with a small bias (-3 mm Hg) and a precision of 9 mm Hg. A Doppler echocardiography systolic pulmonary artery pressure greater than 39 mm Hg predicted pulmonary hypertension (mean pulmonary artery pressure ≥ 25 mm Hg) with 100% sensitivity and specificity. Tricuspid regurgitation maximal velocity greater than 2.82 m/s as well as tricuspid regurgitation pressure gradient greater than 32 mm Hg predicted the presence of pulmonary hypertension. Pulmonary regurgitation was recorded in 10 patients (25%). No correlation was found between pulmonary regurgitation velocities and either mean pulmonary artery pressure or diastolic pulmonary artery pressure. Pulmonary acceleration time less than 57 ms and isovolumic relaxation time less than 40 ms respectively predicted pulmonary hypertension 100% of the time and had a 100% negative predictive value. Tricuspid regurgitation maximal velocity pressure gradient added to invasive central venous pressure accurately estimates systolic pulmonary artery pressure and mean pulmonary artery pressure in ICU patients receiving mechanical ventilation and may predict pulmonary hypertension.

Arterial Pulse Pressure Variation versus Central Venous Pressure as a Predictor for Fluid Responsiveness during Open Major Abdominal Operations

Introduction: Fluid resuscitation is the cornerstone in the management of hemodynamically unstable patients. Dynamic parameters of fluid responsiveness, like pulse pressure variation, have the advantage of being more reliable index for fluid management. Objective: The aim of our study was to compare between arterial pulse pressure variation (PPV) versus central venous pressure (CVP) as a predictor for fluid responsiveness during major open abdominal operations. Patients and Methods: 60 adult patients under general anesthesia with mechanical ventilation underwent open major abdominal surgical procedures were included in our prospective randomized controlled study. Intravenous fluid was infused and monitored by CVP in control group or by PPV in the other group. Hemodynamic variables (heart rate, invasive blood pressure, PPV and CVP) were measured at baseline after anesthesia induction and every 10 min, during first hour of operation, and then every 15 min, till end of surgery. Blood loss and total i.v. fluid & blood transfusion given to patients were recorded and compared between two groups intraoperatively. Results: Patients in the PPV group required more intraoperative fluid and blood transfusion than patients in CVP group to achieve more stable hemodynamic parameters. The fall in blood pressure (>20% of baseline) and increase in heart rate are more common in CVP group (p < 0.05). Conclusion: PPV is a better predictor and a good guide for fluid responsiveness. More stable hemodynamic variables are observed in PPV group.

Study of Relationship between Central Venous Pressure and Peripheral Venous Pressure during Intraoperative Period in Neurosurgical Patients

Abstract Background and Objectives Central venous pressure (CVP) and peripheral venous pressure (PVP) are strongly correlated during various surgeries. This study was designed to examine the consistency of CVP–PVP relationships in circumstances of rapidly fluctuating hemodynamics in neurosurgical patients. Prime objective of this study was to determine if PVP can be an effective alternative to invasive CVP for assessing volume status during neurosurgical procedures when expertise, equipment, and patient’s condition contraindicate invasive monitoring. Subjects and Methods After the approval by the Institutional Ethics Committee, CVP and PVP were measured in 50 neurosurgical patients of the American Society of Anesthesiologists grade I and II operated in supine position. Paired measurements of CVP and PVP were made every 20 minutes, from the starting of anesthesia until the end of surgery; however, in situations of hemodynamic instability, the readings were taken every 5 minutes of interval. Results The study showed a strong correlation between CVP and PVP (Pearson’s correlation coefficient between CVP and PVP, r = 0.89; 95% CI: 0.81–0.93; p &lt; 0.001). Mean CVP was 5.7 ± 0.8 mm of Hg, mean PVP was 10.4 ± 0.6 mm of Hg, and bias between CVP and PVP was 4.7 ± 0.4 (95% CI: − 4.61 to − 4.83). The Bland–Altman analysis showed that limit of agreement to be 4.0 to 5.5 mm of Hg. Conclusion This study demonstrated a strong correlation between CVP and PVP. Therefore, PVP monitoring may be a reliable alternative to CVP monitoring during neurosurgery.

Can non-invasive ventilation modify central venous pressure? Comparison between invasive measurement and ultrasonographic evaluation

Central venous pressure (CVP) is primarily measured to assess intravascular volume status and heart preload. In clinical practice, the measuring device most commonly used in emergency departments and intensive care units, is an electronic transducer that interconnects a central venous catheter (CVC) with a monitoring system. Non-invasive ventilation (NIV) consists in a breathing support that supplies a positive pressure in airways through a mask or a cask though not using an endotracheal prosthesis. In emergency settings, non-invasive ultrasonography evaluation of CVP, and hence of intravascular volume status entail the measurement by a subxiphoid approach of inferior vena cava diameter and its variations in relation to respiratory activity. In the literature, there are many studies analyzing the ability to estimate CVP through ultrasonography, rating inspiratory and expiratory vena cava diameters and their ratio, defined as inferior vena cava collapsibility index (IVC-CI). At the same time, the effects of invasive mechanical ventilation on blood volume and the correlation during ventilation between hemodynamic invasive measurement of CVP and inferior vena cava diameters have already been demonstrated. Nevertheless, there are no available data regarding the hemodynamic effects of NIV and the potential correlations during this kind of ventilation between invasive and non-invasive CVP measurements. Therefore, this study aims to understand whether there exists or not an interrelationship between the values of CVP assessed invasively through a CVC and non-invasively through the IVC-CI in patients with severe respiratory distress, and above all to evaluate if these means of assessment can be influenced using NIV.

New Method for Noninvasive Quantification of Central Venous Pressure by Ultrasound

The central venous pressure (CVP) is essential for assessing the cardiac preload and circulating blood volume in clinic. The invasive CVP measurement by central venous catheter has been reported with various complications. The aim of this study was to develop a new noninvasive method for quantification of CVP by ultrasound. Seventy-six patients who had their CVP monitored for intraoperative or postoperative management were recruited. By accurate location of the collapse point of the internal jugular vein and the center of the right atrium using ultrasound imaging, the height of the fluid column between those 2 points was measured as the noninvasive CVP (CVPn). A total of 118 measurements were performed and compared with the invasive CVP (CVPi). Linear correlation analysis revealed a significant correlation between CVPi and CVPn (preoperative measurements, r=0.90; P<0.01 and postoperative measurements, r=0.93; P<0.01). Bland-Altman plots showed a good agreement between CVPi and CVPn with the mean difference of 0.22 mm Hg (preoperative measurements) and -0.09 mm Hg (postoperative measurements), respectively. The new noninvasive CVP quantification method based on the location of both the collapse point of internal jugular vein and the center of right atrium by ultrasound could be used as a reliable approach for monitoring the hemodynamic status in clinic.

Noninvasive determination of central venous pressure by ultrasound imaging

Objective To determine the central venous pressure (CVP) noninvasively based on hemodynamics principles using ultrasound location of the collapse point of the internal jugular vein. Methods Forty patients were enrolled in this study. The collapse point of the internal jugular vein was located and marked by a linear transducer, the body mark of right atrium was marked on the right lateral wall of the chest. The noninvasive CVP was calculated according to the vertical distance between those two points. The invasive CVP determination by central venous catheter was also carried out on all the patients. Correlation analysis was used to compare the invasive and noninvasive methods. With invasive determination of CVP as the gold standard, the ROC curve of the noninvasive ultrasound method was sketched to explore the optimal cut-off points. Results The correlation analysis reveal high positive correlation between CVPs determined by ultrasound imaging and central venous catheter (r=0.906, P<0.01). By the ROC curve test, fluid column height of 10.75 cm by ultrasound method was determined as the cut-off point, with the sensitivity and specificity of diagnosing elevation of CVP being 88.9% and 93.5% respectively. The corresponding area under the curve was 0.971. Conclusions Ultrasound imaging could be used to determine CVP noninvasively, which would be helpful in diagnosis of the circulatingload of patients. Key words: Ultrasonography; Jugular vein; Central venous pressure

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.

Inferior Vena Cava and Hemodynamic Congestion.

Background:Among the indices able to replace invasive central venous pressure (CVP) measurement for patients with acute decompensated heart failure (ADHF) the diameters of the inferior vena cava (IVC) and their respiratory fluctuations, so-called IVC collapsibility index (IVCCI), measured by echocardiography, have recently gained ground as a quite reliable proxy of CVP.Objectives:The aims of our study were to compare three different ways of evaluating cardiac overload by using the IVC diameters and/or respiratory fluctuations and by calculating the inter-method agreementPatients and Methods:Medical records of patients hospitalized for right or bi-ventricular acute decompensated heart failure from January to December 2013 were retrospectively evaluated. The predictive significance of the IVC expiratory diameter and IVC collapsibility index (IVCCI) was analyzed using three different methods, namely a) the criteria for the indirect estimate of right atrial pressure by Rudski et al. (J Am Soc Echocardiogr. 2010); b) the categorization into three IVCCI classes by Stawicki et al. (J Am Coll Surg. 2009); and c) the subdivision based on the value of the maximum IVC diameter by Pellicori et al. (JACC Cardiovasc Imaging. 2013).Results:Among forty-seven enrolled patients, those classified as affected by persistent congestion were 22 (46.8%) using Rudski’s criteria, or 16 (34%) using Stawicki’s criteria, or 13 (27.6%) using Pellicori’s criteria. The inter-rater agreement was rather poor by comparing Rudski’s criteria with those of Stawicki (Cohen’s kappa = 0.369; 95% CI 0.197 to 0.54), as well as by comparing Rudski’s criteria with those of Pellicori (Cohen’s kappa = 0.299; 95% CI 0.135 to 0.462). Further, a substantially unsatisfactory concordance was also found for Stawicki’s criteria compared to those of Pellicori (Cohen’s kappa= 0.468; 95% CI 0.187 to 0.75).Conclusions:The abovementioned IVC ultrasonographic criteria for hemodynamic congestion appear clearly inconsistent. Alternatively, a sequential or simultaneous combination of clinical scores of congestion, IVC ultrasonographic indices, and circulating levels of natriuretic peptides could be warranted.

Abstract 18265: Determining the Adequacy of Pediatric CPR: CPP Associated With ROSC

Introduction: Human adult studies have shown that the coronary perfusion pressure (CPP) correlates positively with return of spontaneous circulation (ROSC) during CPR. Paradis et al have shown that a CPP of at least 15 mmHg during CPR was associated with ROSC in adult patients. We reviewed in-hospital CPR of pediatric patients between July 2010 and June 2012 at Arkansas Children’s hospital (ACH), who were admitted to the PICU or CVICU at the time of the cardiac arrest and had monitoring lines allowing determination of CPP. Hypothesis: We hypothesized that CPP increases during CPR and the necessary CPP for ROSC in pediatric patients is lower than reported for adults. Methods: Patients with cardiac arrests were identified through ACH CPR registry. CPP was calculated by subtracting the end-diastolic central venous pressure (CVP) from the end-diastolic arterial blood pressure (BP), representing the CPP prior to the next chest compression as defined by the Utstein criteria. We identified 43 patients that had invasive arterial BP and CVP monitoring at the time of the cardiac arrest. Complete monitoring data was available for 10 patients. The mean CPP was calculated in 15 seconds epochs. Results: The mean age for our 10 patients was 320 days (range 12 days - 5.53 years). 8 of the 10 patients had a diagnosis of congenital heart disease and 7 of these 8 patients were admitted to the CVICU for postoperative care. 6 patients were male and 4 were female. Mean weight was 5.8 kg. The mean duration of CPR was 194 seconds. All patients had ROSC; however one patient died within 24 hours of the cardiac arrest, two patients died more than 24 hours after the cardiac arrest. 7 of the 10 patients survived to hospital discharge. Mean CPP was significantly higher for the last 15 second epoch before ROSC compared to the initial 15 second epoch of CPR (22.96 mmHg (SD +/- 9.96 mmHg vs. 5.4 mmHg (SD: +/- 8.2 mmHg), P&lt;0.001). The mean CPP for the minute of CPR prior to ROSC was 15.95 mmHg (standard deviation (SD): +/- 4.8 mmHg). Conclusion: CPP increased during CPR and was significantly higher just prior to ROSC. Mean values in the minute prior to ROSC were similar to that reported in adults. To our knowledge, this is the first descriptive study of CPP during CPR in pediatric patients.

Bedside assessment of right atrial pressure in critically ill septic patients using tissue Doppler ultrasonography

PurposeRight atrial pressure (RAP) is considered a surrogate for right ventricular filling pressure or cardiac preload. It is an important parameter for fluid management in patients with septic shock. It is commonly approximated by the central venous pressure (CVP) either invasively using a catheter placed in the superior vena cava or by bedside ultrasound, in which the size and respiratory variations of the inferior vena cava (IVC) are measured from the subcostal view. Doppler imaging of the tricuspid valve from the apical 4-chamber view has been proposed as an alternative approach for the estimation of RAP. The tricuspid E/Ea ratio is measured, where E is the peak velocity of the early diastolic tricuspid inflow and Ea is the peak velocity of the early diastolic relaxation of the lateral tricuspid annulus. We hypothesized that the tricuspid E/Ea ratio may represent an alternative to IVC metrics, using invasive CVP as the criterion standard, for the assessment of RAP in critically ill septic patients. Materials and methodsA convenience sample of 30 septic patients, both mechanically ventilated and non–mechanically ventilated, was enrolled. Using a portable ultrasound system, maximum velocity of tricuspid E and Ea was measured from the apical 4-chamber view; and IVC diameter and degree of collapse were measured from the subcostal view. Decision tree induction was used to determine the performance of each model compared with invasive CVP. ResultsOur results suggest that a tricuspid E/Ea ratio of greater than 4.7 can predict a CVP greater than 10 mm Hg in septic patients with sensitivity greater than 85% and specificity greater than 90%. ConclusionsIn this pilot study, Doppler imaging of the tricuspid valve provided a valuable alternative for noninvasive bedside estimation of RAP in septic patients.