Effects of dynamic versus static parameter-guided fluid resuscitation in patients with sepsis: A randomized controlled trial.

Background: Fluid resuscitation is an essential component for sepsis treatment. Although several studies demonstrated that dynamic variables were more accurate than static variables for prediction of fluid responsiveness, fluid resuscitation guidance by dynamic variables is not standard for treatment. The objectives were to determine the effects of dynamic inferior vena cava (IVC)-guided versus (vs.) static central venous pressure (CVP)-guided fluid resuscitation in septic patients on mortality; and others, i.e., resuscitation targets, shock duration, fluid and vasopressor amount, invasive respiratory support, length of stay and adverse events. Methods: A single-blind randomized controlled trial was conducted at Thammasat University Hospital between August 2016 and April 2020. Septic patients were stratified by acute physiologic and chronic health evaluation II (APACHE II) <25 or ≥25 and randomized by blocks of 2 and 4 to fluid resuscitation guidance by dynamic IVC or static CVP. Results: Of 124 patients enrolled, 62 were randomized to each group, and one of each was excluded from mortality analysis. Baseline characteristics were comparable. The 30-day mortality rates between dynamic IVC vs. static CVP groups were not different (34.4% vs. 45.9%, p=0.196). Relative risk for 30-day mortality of dynamic IVC group was 0.8 (95%CI=0.5-1.2, p=0.201). Different outcomes were median (interquartile range) of shock duration (0.8 (0.4-1.6) vs. 1.5 (1.1-3.1) days, p=0.001) and norepinephrine (NE) dose (6.8 (3.9-17.8) vs. 16.1 (7.6-53.6) milligrams, p=0.008 and 0.1 (0.1-0.3) vs. 0.3 (0.1-0.8) milligram⋅kilogram -1, p=0.017). Others were not different. Conclusions: Dynamic IVC-guided fluid resuscitation does not affect mortality of septic patients. However, this may reduce shock duration and NE dose, compared with static CVP guidance.

Nitroglycerin versus milrinone for low central venous pressure in patients undergoing laparoscopic hepatectomy: a double-blinded randomized controlled trial.

BACKGROUND: Conventional anesthesia used to reduce central venous pressure (CVP) during hepatectomy includes fluid restriction and vasodilator drugs, which can lead to a reduction in blood perfusion in vital organs and may counteract the benefits of low blood loss. In this study, we hypothesized that milrinone is feasible and effective in controlling low CVP (LCVP) during laparoscopic hepatectomy (LH). Compared with conventional anesthesia such as nitroglycerin, milrinone is beneficial in terms of intraoperative blood loss, surgical environment, hemodynamic stability, and patients' recovery. METHODS: In total, 68 patients undergoing LH under LCVP were randomly divided into the milrinone group (n = 34) and the nitroglycerin group (n = 34). Milrinone was infused with a loading dose of 10 µg/kg followed by a maintenance dose of 0.2-0.5 µg/kg/min and nitroglycerin was administered at a rate of 0.2-0.5 µg/kg/min until the liver lesions were removed. The characteristics of patients, surgery, intraoperative vital signs, blood loss, the condition of the surgical field, the dosage of norepinephrine, perioperative laboratory data, and postoperative complications were compared between groups. Blood loss during LH was considered the primary outcome. RESULTS: Blood loss during hepatectomy and total blood loss were significantly lower in the milrinone group compared with those in the nitroglycerin group (P < 0.05). Both the nitroglycerin group and milrinone group exerted similar CVP (P > 0.05). Nevertheless, the milrinone group had better surgical field grading during liver resection (P < 0.05) and also exhibited higher cardiac index and cardiac output during the surgery (P < 0.05). Significant differences were also found in terms of fluids administered during hepatectomy, urine volume during hepatectomy, total urine volume, and norepinephrine dosage used in the surgery between the two groups. The two groups showed a similar incidence of postoperative complications (P > 0.05). CONCLUSION: Our findings indicate that the intraoperative infusion of milrinone can help in maintaining an LCVP and hemodynamic stability during LH while reducing intraoperative blood loss and providing a better surgical field compared with nitroglycerin. TRIAL REGISTRATION: ChiCTR2200056891,first registered on 22/02/2022.

CENTRAL VENOUS-TO-ARTERIAL CARBON DIOXIDE PARTIAL PRESSURE DIFFERENCE AS A GUIDING PARAMETER FOR CARDIOTONIC DRUG ADMINISTRATION IN PATIENTS WITH EARLY-STAGE SEPTIC SHOCK.

ABSTRACT: Objective: This study aimed to investigate the effect of the central venous-to-arterial carbon dioxide partial pressure difference (Pcv-aCO2) on the administration of cardiotonic drugs in patients with early-stage septic shock. Methods: A retrospective study was conducted on 120 patients suffering from septic shock. At admission, the left ventricular ejection fraction (LVEF) and Pcv-aCO2 of the patients were obtained. On the premise of mean arterial pressure ≥ 65 mm Hg, the patients were divided into two groups according to the treatment approaches adopted by different doctors-control group: LVEF ≤50% and observation group: Pcv-aCO2 ≥ 6. Both groups received cardiotonic therapy. Results: The two groups of patients had similar general conditions and preresuscitation conditions ( P > 0.05). Compared with the control group, the observation group had a higher mean arterial pressure, lactic acid clearance rate, and urine output after 6 h of resuscitation ( P < 0.05), but a lower absolute value of lactic acid, total fluid intake in 24 h, and a lower number of patients receiving renal replacement therapy during hospitalization ( P < 0.05). After 6 hours of resuscitation, the percentages of patients meeting central venous oxygen saturation and central venous pressure targets were not significantly different between the control and observation groups ( P > 0.05). There was no difference in the 28-day mortality rate between the two groups ( P > 0.05). Conclusion: Pcv-aCO2 is more effective than LVEF in guiding the administration of cardiotonic drugs in the treatment of patients with septic shock.

Intraoperative central venous pressure during cardiopulmonary bypass is an alternative indicator for early prediction of acute kidney injury in adult cardiac surgery.

BACKGROUND: The relationship between venous congestion in cardiopulmonary bypass (CPB) and acute kidney injury (AKI) in cardiac surgery has not utterly substantiated. This study aimed at investigate the relationship between CVP in CPB and the occurrence of AKI. METHODS: We retrospectively reviewed 2048 consecutive patients with cardiovascular disease undergoing cardiac procedure with CPB from January 2018 to December 2022. We used the median CVP value obtained during CPB for our analysis and patients were grouped according to this parameter. The primary outcomes were AKI and renal replacement therapy(RRT). Multivariable logistic regression was used to explore the association between CVP and AKI. RESULTS: A total of 2048 patients were enrolled in our study and divided into high CVP group (CVP ≥ 6.5 mmHg) and low CVP group (CVP < 6.5 mmHg) according to the median CVP value. Patients in high CVP group had the high AKI and RRT rate when compared to the low CVPgroup[(367/912,40.24%)vs.(408/1136,35.92%),P = 0.045;(16/912,1.75%vs.9/1136;0.79%), P = 0.049]. Multivariate logistic regression analysis displayed CVP played an indispensable part in development of renal failure in surgical. CONCLUSIONS: Elevated CVP(≥ 6.5mmH2OmmHg) in CPB during cardiac operation is associated with an increased risk of AKI in cardiovascular surgery patients. Clinical attention should be paid to the potential role of CVP in predicting the occurrence of AKI.

Haemodynamic monitoring during noncardiac surgery: past, present, and future.

During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery - and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential. We therefore revisit the pathophysiologic rationale for intraoperative monitoring of haemodynamic variables, describe the history, current use, and future technological developments of monitoring methods, and finally briefly summarise the evidence that haemodynamic management can improve patient-centred outcomes.

Echocardiographic features of right ventricle in septic patients with elevated central venous pressure.

BACKGROUND: Elevated central venous pressure (CVP) is deemed as a sign of right ventricular (RV) dysfunction. We aimed to characterize the echocardiographic features of RV in septic patients with elevated CVP, and quantify associations between RV function parameters and 30-day mortality. METHODS: We retrospectively reviewed a cohort of septic patients with CVP ≥ 8 mmHg in a tertiary hospital intensive care unit. General characteristics and echocardiographic parameters including tricuspid annular plane systolic excursion (TAPSE), pulmonary vascular resistance (PVR) as well as prognostic data were collected. Associations between RV function parameters and 30-day mortality were assessed using Cox regression models. RESULTS: Echocardiography was performed in 244 septic patients with CVP ≥ 8 mmHg. Echocardiographic findings revealed that various types of abnormal RV function can occur individually or collectively. Prevalence of RV systolic dysfunction was 46%, prevalence of RV enlargement was 34%, and prevalence of PVR increase was 14%. In addition, we collected haemodynamic consequences and found that prevalence of systemic venous congestion was 16%, prevalence of RV-pulmonary artery decoupling was 34%, and prevalence of low cardiac index (CI) was 23%. The 30-day mortality of the enrolled population was 24.2%. In a Cox regression analysis, TAPSE (HR:0.542, 95% CI:0.302-0.972, p = 0.040) and PVR (HR:1.384, 95% CI:1.007-1.903, p = 0.045) were independently associated with 30-day mortality. CONCLUSIONS: Echocardiographic findings demonstrated a high prevalence of RV-related abnormalities (RV enlargement, RV systolic dysfunction and PVR increase) in septic patients with elevated CVP. Among those echocardiographic parameters, TAPSE and PVR were independently associated with 30-day mortality in these patients.

Positive correlation between echocardiographic tricuspid E peak velocity and central venous pressure in dogs: A preliminary study.

In the absence of vascular obstruction, central venous pressure (CVP) is a hydrostatic pressure in the cranial and caudal vena cava, providing valuable information about cardiac function and intravascular volume status. It is also a component in evaluating volume resuscitation in patients with septic shock and monitoring patients with right heart disease, pericardial disease, or volume depletion. Central venous pressure is calculated in dogs by invasive central venous catheterization, which is considered high-risk and impractical in critically ill patients. This study aimed to investigate the feasibility of using echocardiographic tricuspid E/E' as a noninvasive method to estimate CVP in anesthetized healthy dogs under controlled hypovolemic conditions. Ten male mixed-breed dogs were included in the study after a thorough health assessment. For hypovolemia induction, blood withdrawal was performed, and echocardiographic factors of the tricuspid valve, including peak E and E' velocities, were measured during CVP reduction. Repeated measures analysis of variance and Bonferroni post hoc tests were employed to compare the average difference between measured echocardiographic indices and CVP values derived from catheterization and intermittent measurement methods. Spearman's ρ correlation coefficient was used to evaluate the correlation between echocardiographic indices and CVP. E peak velocity had a significant negative correlation with venous blood pressure phases (r = -0.44, P = .001), indicating a decrease in peak E velocity with progressive CVP reduction. However, tricuspid valve E' peak velocity and E/E' did not correlate with CVP, suggesting that these parameters are not reliable for CVP estimation in dogs.

Exploring congestion endotypes and their distinct clinical outcomes among ICU patients: A post-hoc analysis.

BACKGROUND: In the intensive care unit (ICU) patients, fluid overload and congestion are associated with worse outcomes. Because of the heterogeneity of ICU patients, we hypothesized that there may exist different endotypes of congestion. The aim of this study was to identify endotypes of congestion and their association with outcomes. METHODS: We conducted an unsupervised hierarchical clustering analysis on 145 patients admitted to ICU to identify endotypes. We measured several parameters related to clinical context, volume status, filling pressure, and venous congestion. These parameters included NT-proBNP, central venous pressure (CVP), the mitral E/e' ratio, the systolic/diastolic ratio of hepatic veins' flow velocity, the mean diameter of the inferior vena cava (IVC) and its variations, stroke volume changes following passive leg raising, the portal vein pulsatility index, and the venous renal impedance index. RESULTS: Three distinct endotypes were identified: (1) "hemodynamic congestion" endotype (n = 75) with moderate alterations of ventricular function, increased CVP and left filling pressure values, and moderate fluid overload; (2) "volume overload congestion" endotype (n = 50); with normal cardiac function and filling pressure despite high positive fluid balance (fluid overload); (3) "systemic congestion" endotype (n = 20) with severe alterations of left and right ventricular functions, increased CVP and left ventricular filling pressure values. These endotypes vary significantly in ICU admission reasons, acute kidney injury rates, mortality, and length of ICU/hospital stay. CONCLUSIONS: Our analysis revealed three unique congestion endotypes in ICU patients, each with distinct pathophysiological features and outcomes. These endotypes are identifiable through key ultrasonographic characteristics at the bedside. CLINICAL TRIAL GOV: NCT04680728.

Estimation of the transpulmonary pressure from the central venous pressure in mechanically ventilated patients.

Transpulmonary pressure (PL) calculation requires esophageal pressure (PES) as a surrogate of pleural pressure (Ppl), but its calibration is a cumbersome technique. Central venous pressure (CVP) swings may reflect tidal variations in Ppl and could be used instead of PES, but the interpretation of CVP waveforms could be difficult due to superposition of heartbeat-induced pressure changes. Thus, we developed a digital filter able to remove the cardiac noise to obtain a filtered CVP (f-CVP). The aim of the study was to evaluate the accuracy of CVP and filtered CVP swings (ΔCVP and Δf-CVP, respectively) in estimating esophageal respiratory swings (ΔPES) and compare PL calculated with CVP, f-CVP and PES; then we tested the diagnostic accuracy of the f-CVP method to identify unsafe high PL levels, defined as PL>10 cmH2O. Twenty patients with acute respiratory failure (defined as PaO2/FiO2 ratio below 200 mmHg) treated with invasive mechanical ventilation and monitored with an esophageal balloon and central venous catheter were enrolled prospectively. For each patient a recording session at baseline was performed, repeated if a modification in ventilatory settings occurred. PES, CVP and airway pressure during an end-inspiratory and -expiratory pause were simultaneously recorded; CVP, f-CVP and PES waveforms were analyzed off-line and used to calculate transpulmonary pressure (PLCVP, PLf-CVP, PLPES, respectively). Δf-CVP correlated better than ΔCVP with ΔPES (r = 0.8, p = 0.001 vs. r = 0.08, p = 0.73), with a lower bias in Bland Altman analysis in favor of PLf-CVP (mean bias - 0.16, Limits of Agreement (LoA) -1.31, 0.98 cmH2O vs. mean bias - 0.79, LoA - 3.14, 1.55 cmH2O). Both PLf-CVP and PLCVP correlated well with PLPES (r = 0.98, p < 0.001 vs. r = 0.94, p < 0.001), again with a lower bias in Bland Altman analysis in favor of PLf-CVP (0.15, LoA - 0.95, 1.26 cmH2O vs. 0.80, LoA - 1.51, 3.12, cmH2O). PLf-CVP discriminated high PL value with an area under the receiver operating characteristic curve 0.99 (standard deviation, SD, 0.02) (AUC difference = 0.01 [-0.024; 0.05], p = 0.48). In mechanically ventilated patients with acute respiratory failure, the digital filtered CVP estimated ΔPES and PL obtained from digital filtered CVP represented a reliable value of standard PL measured with the esophageal method and could identify patients with non-protective ventilation settings.

Oxygen inhalation decreases the central venous pressure in adult patients late after Fontan operations.

BACKGROUND: Elevated central venous pressure (CVP) and decreased arterial oxygen saturation (SaO2) are the characteristics of patients after Fontan operations and determine morbidity and mortality in the long-term. Oxygen inhalation therapy theoretically increases SaO2 and may decrease the elevated CVP in these patients. However, there is no previous study to support this hypothesis. This study aimed to determine the acute effects of oxygen inhalation on the hemodynamics of adult patients late after Fontan operations using cardiac catheterization. METHODS: This study enrolled 58 consecutive adult patients (median age, 30 years; female, n = 24) who had undergone Fontan operations. We assessed the hemodynamic changes during oxygen inhalation (2 L/min) with a nasal cannula in cardiac catheterization. We divided the studied patients into two groups according to the reduction in CVP during oxygen inhalation using the median value: responders (>2 mmHg) and non-responders (≤2 mmHg). Clinical characteristics of the responders to oxygen inhalation were investigated with uni- and multivariate analyses. RESULTS: SaO2 increased from 93.3 % (91.3-94.5 %) to 97.5 % (95.2-98.4 %) (p < 0.001) and CVP decreased from 12 mmHg (11-14 mmHg) to 10 mmHg (9-12 mmHg) (p < 0.001) after oxygen inhalation. There was a weak but significant correlation between the increase in SaO2 and the decrease in CVP (R = 0.29, p = 0.025). Pulmonary blood flow increased from 4.1 L/min (3.5-5.0 L/min) to 4.4 L/min (3.7-5.3 L/min) (p = 0.007), while systemic blood flow showed no significant changes. A multivariate analysis revealed that high baseline CVP was associated with a larger decrease in CVP (>2 mmHg) after oxygen inhalation. CONCLUSIONS: Oxygen inhalation increased SaO2 and decreased CVP, especially in patients with high baseline CVP. Further studies with home oxygen therapy are needed to investigate the long-term effects of oxygen inhalation in adult patients who underwent Fontan operations.

The Ultrasound Hepato-Jugular Reflux: Measuring the Hepato-Jugular Reflux with Ultrasound with Comparison to Invasive Right Heart Catheterization.

BACKGROUND: Ultrasound can overcome barriers to visualizing the internal jugular vein, allowing hepato-jugular reflux and jugular venous pressure measurement. We aimed to determine operating characteristics of the ultrasound hepato-jugular reflux and ultrasound jugular venous pressure predicting right atrial and pulmonary capillary occlusion pressures. METHODS: In a prospective observational cohort at three US academic hospitals the hepato-jugular reflux and jugular venous pressure were measured with ultrasound before right heart catheterization. Receiver operating curves, likelihood ratios, and regression models were utilized to compare the ultrasound hepato-jugular reflux and ultrasound jugular venous pressure to the right atrial and pulmonary capillary occlusion pressures. RESULTS: In 99 adults undergoing right heart catheterization, an ultrasound hepato-jugular reflux had a negative likelihood ratio of 0.4 if 0 cm and a positive likelihood ratio of 4.3 if ≥ 1.5 cm for predicting a pulmonary capillary occlusion pressure ≥ 15 mmHg. Regression modeling predicting pulmonary capillary occlusion pressure was not only improved by including the ultrasound hepato-jugular reflux (P < .001), it was the more impactful predictor compared with the ultrasound jugular venous pressure (adjusted odds ratio 2.6 vs 1.2). The ultrasound hepato-jugular reflux showed substantial agreement (kappa 0.76; 95% confidence interval, 0.30-1.21), with poor agreement for the ultrasound jugular venous pressure (kappa 0.11; 95% confidence interval, -0.37-0.58). CONCLUSION: In patients undergoing right heart catheterization, the ultrasound hepato-jugular reflux is reproducible, has modest impact on the probability of a normal pulmonary capillary occlusion pressure when 0 cm, and more substantial impact on the probability of an elevated pulmonary capillary occlusion pressure when ≥ 1.5 cm.

Simultaneous Venous-Arterial Doppler Ultrasound During Early Fluid Resuscitation to Characterize a Novel Doppler Starling Curve: A Prospective Observational Pilot Study.

Background: The likelihood of a patient being preload responsive-a state where the cardiac output or stroke volume (SV) increases significantly in response to preload-depends on both cardiac filling and function. This relationship is described by the canonical Frank-Starling curve. Research Question: We hypothesize that a novel method for phenotyping hypoperfused patients (ie, the "Doppler Starling curve") using synchronously measured jugular venous Doppler as a marker of central venous pressure (CVP) and corrected flow time of the carotid artery (ccFT) as a surrogate for SV will refine the pretest probability of preload responsiveness/unresponsiveness. Study Design and Methods: We retrospectively analyzed a prospectively collected convenience sample of hypoperfused adult emergency department (ED) patients. Doppler measurements were obtained before and during a preload challenge using a wireless, wearable Doppler ultrasound system. Based on internal jugular and carotid artery Doppler surrogates of CVP and SV, respectively, we placed hemodynamic assessments into quadrants (Qx) prior to preload augmentation: low CVP with normal SV (Q1), high CVP and normal SV (Q2), low CVP and low SV (Q3) and high CVP and low SV (Q4). The proportion of preload responsive and unresponsive assessments in each quadrant was calculated based on the maximal change in ccFT (ccFTΔ) during either a passive leg raise or rapid fluid challenge. Results: We analyzed 41 patients (68 hemodynamic assessments) between February and April 2021. The prevalence of each phenotype was: 15 (22%) in Q1, 8 (12%) in Q2, 39 (57%) in Q3, and 6 (9%) in Q4. Preload unresponsiveness rates were: Q1, 20%; Q2, 50%; Q3, 33%, and Q4, 67%. Interpretation: Even fluid naïve ED patients with sonographic estimates of low CVP have high rates of fluid unresponsiveness, making dynamic testing valuable to prevent ineffective IVF administration.

Central venous pressure combined with renal venous impedance index in predicting the acute kidney injury after thoracic and abdominal (non-cardiac) surgery.

BACKGROUND: In the 21st century, 13% of patients undergoing open abdominal surgery, 25% of patients undergoing heart surgery, and 57% of patients admitted to the intensive care unit (ICU) are affected by acute kidney injury (AKI). METHODS: This prospective observational study included patients admitted directly to the ICU between June 2021 and December 2021. RESULTS: A total of 81 patients were enrolled after thoracic and abdominal (non-cardiac) surgery; 36 patients (44.4%) were diagnosed with AKI occurred within 7 days after surgery. Six-hour postoperative central venous pressure(CVP) was a risk factor for AKI in thoracic and abdominal (non-cardiac) postoperative patients (odds ratio [OR], 1.418; 95% confidence intervals [CI], 1.106-1.819; P = 0.006). Six-hour postoperative vein impedance index(VII) and CVP were significantly positively correlated (P = 0.031). The combination of 6-h postoperative VII with CVP (VII ≥0.34, CVP ≥7.5 mmHg) showed an area under the curve (AUC) of 0.787, In the subgroup analysis of patients with 6-h postoperative CVP <7.5 mmHg, there was a significant statistical difference in 6-h postoperative VII between the groups and those without AKI (P = 0.048). At 6-h postoperative CVP <7.5 mmHg, VII of ≥0.44 had a predictive value for AKI after thoracic and abdominal (non-cardiac) surgery, with an AUC of 0.669, a sensitivity of 41.2%, and a specificity of 94.4%. CONCLUSION: Six-hour postoperative CVP combined with VII can better predict the occurrence of AKI occurred within 7 days after thoracic and abdominal (non-cardiac) surgery but cannot predict the severity of AKI.

Goal-directed fluid therapy during post-resection phase in low central venous pressure assisted laparoscopic hepatectomy: a randomized controlled superiority trial.

PURPOSE: The purpose of this prospective single blinded randomized controlled trial was to find out whether goal-directed fluid therapy (GDFT) strategy in post-transection period in low central venous pressure (CVP) assisted laparoscopic hepatectomy (LH) has more benefit than traditional fluid strategy. METHODS: Between April 2020 and Dec 2021, patients who were scheduled for laparoscopic liver resection surgery were eligible to participate in the study. Patients were randomly divided into two groups: control group that received traditional fluid strategy in post-transection period in low CVP assisted laparoscopic hepatectomy and GDFT strategy group that received GDFT strategy in post-transection period. The primary outcome parameter is the incidence of postoperative complications. Secondary outcome parameters include perioperative clinical outcomes, postoperative clinical outcomes, length of hospital stay after surgery, postoperative lactic acid, fluids and vasoactive medications during the operation. RESULTS: A total of 159 patients in the control group and 160 patients in the GDFT were included. Two groups had no significant difference in the incidence of postoperative complications including pneumonia (P = 0.34), acute kidney injury (P = 0.72), hepatic insufficiency (P = 0.25), pleural effusion (P = 0.08) and seroperitoneum (P = 1.00), respectively. The amount of perioperative urine output is fewer in GDFT group than in the control group (P = 0.0354), while other perioperative variables and postoperative variables were comparable between two groups. CONCLUSIONS: The results show the implementation of GDFT strategy is not associated with fewer postoperative complications. GDFT strategy did not result in improved outcomes in low CVP-assisted laparoscopic hepatectomy.

Method for measuring jugular venous pulse with a miniature gyroscope sensor patch.

The right internal jugular vein is connected to the right atrium of the heart via the superior vena cava, and consequently its pressure, known as the jugular venous pressure or the jugular venous pulse (JVP), is an important indicator of cardiac function. The JVP can be estimated visually from the neck but it is rather difficult and imprecise. In this article we propose a method to measure the JVP using a motion sensor patch attached to the neck. The JVP signal was extracted from the sensor's 3-axes gyroscope signal and aligned with simultaneously measured ECG and seismocardiogram signals.The method was tested on 20 healthy subjects. The timings of the characteristic JVP waves were compared with the ECG R peaks and seismocardiogram heart sounds S1 and S2. The JVP was reliably measured from 18 subjects with all three waves identified. The timings of the waves were also physiologically plausible when compared to the ECG R peak and the heart sounds. Importantly, the JVP was also found to modulate with respiration, further indicating that the measured signal was indeed the JVP and not the carotid pulse.The results show that the JVP can be measured with a wearable patch-like device registering the delicate motions of the right internal jugular vein. The method has potential to be developed into a clinical tool to measure cardiac health in diseases such as heart failure and chronic obstructive pulmonary disease (COPD).Clinical relevance-The developed method could enable an affordable measurement of clinically important cardiac parameter, jugular venous pulse, as a part of a routine examination.

Assessment of venous pressure by compression sonography of the internal jugular vein during 3 days of bed rest.

Compression sonography has been proposed as a method for non-invasive measurement of venous pressures during spaceflight, but initial reports of venous pressure measured by compression ultrasound conflict with prior reports of invasively measured central venous pressure (CVP). The aim of this study is to determine the agreement of compression sonography of the internal jugular vein (IJVP) with invasive measures of CVP over a range of pressures relevant to microgravity exposure. Ten healthy volunteers (18-55 years, five female) completed two 3-day sessions of supine bed rest to simulate microgravity. IJVP and CVP were measured in the seated position, and in the supine position throughout 3 days of bed rest. The range of CVP recorded was in line with previous reports of CVP during changes in posture on Earth and in microgravity. The correlation between IJVP and CVP was poor when measured during spontaneous breathing (r = 0.29; R2  = 0.09; P = 0.0002; standard error of the estimate (SEE) = 3.0 mmHg) or end-expiration CVP (CVPEE ; r = 0.19; R2  = 0.04; P = 0.121; SEE = 3.0 mmHg). There was a modest correlation between the change in CVP and the change in IJVP for both spontaneous ΔCVP (r = 0.49; R2  = 0.24; P < 0.0001) and ΔCVPEE (r = 0.58; R2  = 0.34; P < 0.0001). Bland-Altman analysis of IJVP revealed a large positive bias compared to spontaneous breathing CVP (3.6 mmHg; SD = 4.0; CV = 85%; P < 0.0001) and CVPEE (3.6 mmHg; SD = 4.2; CV = 84%; P < 0.0001). Assessment of absolute IJVP via compression sonography correlated poorly with direct measurements of CVP by invasive catheterization over a range of venous pressures that are physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time. NEW FINDINGS: What is the central question of this study? Compression sonography has been proposed as a novel method for non-invasive measurement of venous pressures during spaceflight. However, the accuracy has not yet been confirmed in the range of CVP experienced by astronauts during spaceflight. What is the main finding and its importance? Our data show that compression sonography of the internal jugular vein correlates poorly with direct measurement of central venous pressures in a range that is physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time.

Early persistent exposure to high CVP is associated with increased mortality and AKI in septic shock: A retrospective study.

PURPOSE: This study's objective was to investigate the association between exposure to different intensities of central venous pressure (CVP) over time in patients with septic shock with 28-day mortality and acute kidney injury (AKI). MATERIALS AND METHODS: We obtained data from the AmsterdamUMCdb, which includes data on patients ≥18 years old with septic shock undergoing CVP monitoring. The primary outcome was mortality by day 28. Piecewise exponential additive mixed models were used to estimate the strength of the association over time. RESULTS: 9668 patients were included in the study. They exhibited 8.2% overall mortality at 28 days and 41.1% AKI incidence. Daily time-weighted average CVP was strongly associated with increased mortality at 28 days, primarily within 24 h of ICU admission. The mortality rate of patients was lowest when the CVP was 6-12 cmH2O. When the time of high CVP (TWA-CVP >12 cmH2O) exposure within the first 24 h was >5 h, the risk of death increased by 2.69-fold. Additionally, patients exposed to high CVP had a significantly increased risk of developing AKI. CONCLUSIONS: The optimal CVP range for patients with septic shock within 24 h of ICU admission is 6-12 cmH2O. Mortality increased when patients were exposed to high CVP for >5 h.