High Central Venous Pressure and Right Ventricle Size Are Related to Non-decreased Left Ventricle Stroke Volume After Negative Fluid Balance in Critically Ill Patients: A Single Prospective Observational Study

Correlation between ultrasound-measured inferior vena cava diameter and peripherally inserted central catheter measured central venous pressure in low birth weight infants

OBJECTIVE

To evaluate the correlation between ultrasound-measured inferior vena cava (IVC) diameter and central venous pressure (CVP) measured by peripherally inserted central catheter (PICC) in low birth weight infants (LBWI) and explore potential influencing factors.

METHODS

This retrospective study included 120 LBWI with birth weights below 2500 g who required umbilical vein catheterization at Huadu District People's Hospital of Guangzhou from May 2022 to April 2024. Infants were categorized based on PICC catheterization into two groups. Clinical data, including ultrasound-measured IVC small diameter (SD) and large diameter (LD) at the level of the left portal vein, were collected. The SD/LD ratio (S/L) was calculated, and logistic regression analyses (univariate and multivariate) were performed to identify factors influencing PICC catheterization. Correlations between SD, LD, S/L, and CVP were analyzed.

RESULTS

Multivariate logistic regression identified gestational age, birth weight, SD, S/L, and CVP as significant factors influencing PICC catheterization in LBWI (all P < 0.05). SD and S/L showed a positive correlation with CVP (both P < 0.05). The S/L ratio was significantly correlated with gestational age, birth weight, ventilator mode, tricuspid regurgitation, and vasoactive drug use (all P < 0.05).

CONCLUSION

Birth weight, SD, S/L ratio, and CVP are significant factors affecting PICC placement in LBWI. There is a notable correlation between ultrasound-measured IVC SD and S/L ratio and PICC-measured CVP in LBWIs.

Central Venous Pressure as a Predictor of Acute Kidney Injury in Cardiac Surgery: A Systematic Review of Observational Studies

Background/Objectives: Acute kidney injury (AKI) is a syndrome characterized by impaired kidney function, which is associated with reduced survival and increased morbidity. Central venous pressure (CVP) is a widely used hemodynamic parameter for assessing the volume status of patients and evaluating their response to fluid resuscitation. This systematic review aims to analyze various prospective and retrospective observational and controlled trials to determine the association between CVP and the risk of developing AKI in patients undergoing cardiac surgery. Additionally, it examines whether elevated CVP serves as an accurate predictor of AKI in this patient population. Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using PubMed as the primary database. The search focused on studies published after 2014 that included adult patients undergoing cardiac surgery with reported measurements of CVP and kidney function assessment. Studies conducted on animals, pediatric populations, those published before 2014, or in languages other than English were excluded from the review. Results: Through the analysis of 21 studies, a clear association between higher CVP and increased AKI risk emerged. The most critical CVP thresholds identified were 10 mmHg, 12 mmHg, 14 mmHg, and 20 mmHg, with risk increasing progressively beyond these values. CVP ≥ 10 mmHg was the most commonly reported cutoff for elevated AKI risk, showing 1.42 to 4.53 times increased odds. CVP ≥ 12 mmHg further amplified the risk, while CVP ≥ 14 mmHg was consistently associated with severe AKI and the need for RRT. The highest threshold (CVP ≥ 20 mmHg) showed the greatest risk escalation, linked to fluid overload, right heart failure, and mortality. Studies also suggest an optimal CVP range of 6-8 mmHg to minimize AKI incidence. Conclusions: Elevated CVP is an independent risk factor for the development of AKI in patients undergoing cardiac surgery. These findings suggest that CVP monitoring can play a significant role in predicting AKI and guiding perioperative management strategies.

Cardiovascular Subphenotypes in ARDS: Diagnostic and Therapeutic Implications and Overlap with Other ARDS Subphenotypes

Acute respiratory distress syndrome (ARDS) is a highly heterogeneous clinical condition. Shock is a poor prognostic sign in ARDS, and heterogeneity in its pathophysiology may be a barrier to its effective treatment. Although right ventricular dysfunction is commonly implicated, there is no consensus definition for its diagnosis, and left ventricular function is neglected. There is a need to identify the homogenous subgroups within ARDS, that have a similar pathobiology, which can then be treated with targeted therapies. Haemodynamic clustering analyses in patients with ARDS have identified two subphenotypes of increasingly severe right ventricular injury, and a further subphenotype of hyperdynamic left ventricular function. In this review, we discuss how phenotyping the cardiovascular system in ARDS may align with haemodynamic pathophysiology, can aid in optimally defining right ventricular dysfunction and can identify tailored therapeutic targets for shock in ARDS. Additionally, clustering analyses of inflammatory, clinical and radiographic data describe other subphenotypes in ARDS. We detail the potential overlap between these and the cardiovascular phenotypes.

Diuretics depletion improves cardiac output and ventriculo-arterial coupling in congestive ICU patients during hemodynamic de-escalation

PURPOSE

Congestion was shown to hamper organ perfusion, but the exact timing of diuretic initiation during hemodynamic de-escalation in shock is unclear. The aim of this study was to describe the hemodynamic effects of diuretic initiation in the stabilized shock.

METHODS

We performed a monocentric, retrospective analysis, in a cardiovascular medico-surgical ICU. We included consecutive resuscitated adult patients, for whom the clinician decided to introduce loop diuretic treatment for clinical signs of fluid overload. The patients were hemodynamically evaluated at the moment of diuretic introduction and 24 h later.

RESULTS

Seventy ICU patients were included in this study, with a median duration of ICU stay before diuretic initiation of 2 [1-3] days. 51(73%) patients were classified as congestive (central venous pressure > 12 mmHg). After treatment, the cardiac index increased towards normal values in the congestive group (2.7 ± 0.8 L min^- 1 m^- 2 from 2.5 ± 0.8 L min^- 1 m^- 2, p = 0.042), but not in the non-congestive group (2.7 ± 0.7 L min^- 1 m^- 2 from baseline 2.7 ± 0.8 L min^- 1 m^- 2, p = 0.968). A decrease in arterial lactate concentrations was observed in the congestive group (2.1 ± 2 mmol L^- 1 vs. 1.3 ± 0.6 mmol L^- 1, p < 0.001). The diuretic therapy was associated with an improvement of ventriculo-arterial coupling comparing with baseline values in the congestive group (1.69 ± 1 vs. 1.92 ± 1.5, p = 0.03). The norepinephrine use decreased in congestive patients (p = 0.021), but not in the non-congestive group (p = 0.467).

CONCLUSION

The initiation of diuretics in ICU congestive patients with stabilized shock was associated with improvement of cardiac index, ventriculo-arterial coupling, and tissue perfusion parameter. These effects were not observed in non-congestive patients.

Should central venous pressure be used to guide critical care management?

Central venous pressure is no longer routinely used to guide therapy in UK intensive care units, owing to evidence that it poorly predicts fluid responsiveness. This article reviews whether central venous pressure monitoring should be used to guide critical care management in certain patients.

Portal Vein Pulsatility as a Dynamic Marker of Venous Congestion Following Cardiac Surgery: An Interventional Study Using Positive End-Expiratory Pressure

We aimed to assess variations in the portal vein pulsatility index (PI) during mechanical ventilation following cardiac surgery.

METHOD

After ethical approval, we conducted a prospective monocentric study at Amiens University Hospital. Patients under mechanical ventilation following cardiac surgery were enrolled. Doppler evaluation of the portal vein (PV) was performed by transthoracic echography. The maximum velocity (VMAX) and minimum velocity (VMIN) of the PV were measured in pulsed Doppler mode. The PI was calculated using the following formula (VMAX - VMIN)/(VMax). A positive end-expiratory pressure (PEEP) incremental trial was performed from 0 to 15 cmH2O, with increments of 5 cmH2O. The PI (%) was assessed at baseline and PEEP 5, 10, and 15 cmH2O. Echocardiographic and hemodynamic parameters were recorded.

RESULTS

In total, 144 patients were screened from February 2018 to March 2019 and 29 were enrolled. Central venous pressure significantly increased for each PEEP increment. Stroke volumes were significantly lower after PEEP incrementation, with 52 mL (50-55) at PEEP 0 cmH2O and 30 mL (25-45) at PEEP 15 cmH2O, (p < 0.0001). The PI significantly increased with PEEP incrementation, from 9% (5-15) at PEEP 0 cmH2O to 15% (5-22) at PEEP 5 cmH2O, 34% (23-44) at PEEP 10 cmH2O, and 45% (25-49) at PEEP 15 cmH2O (p < 0.001).

CONCLUSION

In the present study, PI appears to be a dynamic marker of the interaction between mechanical ventilation and right heart pressure after cardiac surgery. The PI could be a useful noninvasive tool to monitor venous congestion associated with mechanical ventilation.