IVC measurement for the noninvasive evaluation of central venous pressure

Heart in Focus: Advancing Pericardial Effusion Diagnosis With Point-of-Care Ultrasound

Pericardial effusion refers to the accumulation of fluid within the pericardial sac, the double-layered membrane surrounding the heart. It can be caused by various medical conditions and may lead to serious complications if not diagnosed and managed promptly. Point-of-care ultrasound (POCUS) has emerged as a valuable tool in the clinical evaluation of pericardial effusions, offering real-time visualization and aiding in the assessment of its size, characteristics, and potential hemodynamic impact. This comprehensive revision explores the utility of POCUS in diagnosing and managing pericardial effusions. POCUS has gained prominence as a bedside diagnostic tool due to its immediacy, accuracy, and non-invasive nature. This study investigates how POCUS can address critical gaps in current diagnostic approaches, such as delays in diagnosis using traditional imaging modalities and challenges in resource-limited settings, thereby enhancing patient outcomes and clinical decision-making. A search was conducted on PubMed in August of 2023, using the keywords "POCUS" and "pericardial" as MeSH terms and reference mining. A total of 19 articles were included in this review. Characterization and quantification of pericardial effusion (PEF) using POCUS can provide clinicians with critical clues regarding the underlying etiology. This information, combined with other hemodynamic parameters, should guide subsequent management decisions. POCUS enables the identification of key sonographic findings, such as diastolic collapse of the right chambers, abnormal septal movement, and an engorged inferior vena cava (IVC), which together raise a high clinical suspicion of cardiac tamponade. Beyond its utility in identifying tamponade, POCUS plays a significant role in detecting subtle yet life-threatening conditions, such as aortic dissection, which may manifest as pericardial effusion due to hemopericardium. While POCUS is not definitive for diagnosing aortic dissection, indirect findings such as a pericardial effusion with hemodynamic compromise, coupled with high clinical suspicion, should prompt further imaging like CT angiography for confirmation. We propose an algorithmic approach: if cardiac tamponade is confirmed on POCUS, emergent pericardiocentesis is warranted. If ruled out, further investigations should be directed toward identifying the underlying cause of the PEF, including potentially ruling out aortic dissection to avoid missing a subtle but critical condition. POCUS has revolutionized the clinical evaluation of pericardial effusions, providing clinicians with a rapid and accurate bedside tool for diagnosis and management. Its ability to assess effusion size, identify cardiac tamponade, and guide pericardiocentesis procedures has proven invaluable in improving patient outcomes. Integrating POCUS into routine clinical practice enhances diagnostic accuracy and timely intervention, ensuring better care for patients with pericardial effusions. However, it is important to acknowledge its limitations. POCUS is highly operator-dependent, with diagnostic accuracy varying based on the clinician's experience and training. Additionally, the availability of ultrasound equipment and adequately trained personnel can be a barrier, particularly in resource-limited settings. Addressing these challenges is crucial to maximizing the utility of POCUS in clinical practice.

Hepatic vein Doppler ultrasound to estimate central venous pressure in mechanically ventilated children

Monitoring central venous pressure (CVP) is crucial for managing critically ill patients yet poses challenges in pediatric cases. This study aimed to correlate CVP with hepatic vein Doppler and IVC ultrasound variables in children. Mechanically ventilated children underwent simultaneous ultrasound and CVP measurements. Hepatic vein Doppler assessed peak velocities (A, S, V, D) and systolic filling fraction. IVC ultrasound included respiratory variability indices, IVC/aorta ratio, and IVC/body surface area ratio. Fifty-three children were included (median age of 8.3 months and weight of 6.3 kg). Significant correlations were found between CVP values and all hepatic vein Doppler-based variables. The strongest correlation was found between CVP and the sum of the absolute values of the A- and D-wave peak velocities (AD velocity), with a ρ = 0.61 (95% confidence interval [CI] of 0.40 to 0.75; p < 0.001). The AD velocity > 38.55 cm/s was able to discriminate patients with CPV > 12 mmHg with a sensitivity of 100%, specificity of 95.3%, positive predictive value of 83.3%, and negative predictive value of 100%. No correlations were observed between CVP and variables derived from IVC respiratory variability indices or the IVC/aorta ratio. Conclusion: Hepatic vein Doppler ultrasound provides variables that significantly correlate with CVP and may be useful for estimating cardiac preload in mechanically ventilated children. Indices derived from IVC ultrasound were not reliable for estimating CVP. What is known? • Increased central venous pressure (CVP) can cause interstitial edema and reduce vital organ perfusion, leading to organic dysfunctions, with encapsulated organs such as the kidneys and liver being at higher risk. • However, measuring CVP in children poses challenges due to the difficulties and risks of central venous catheterization, frequent partial or total luminal obstructions in venous catheters, and potential technical errors in measurements. What is new? • Variables obtained through hepatic vein Doppler ultrasonography outperformed those obtained by inferior vena cava ultrasound for estimating CVP in this population. • Hepatic vein Doppler ultrasonography holds potential as an accurate, safe, and non-invasive method for discriminating patients with increased cardiac preload.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Use of Real-Time Cine MRI to Assess the Respirophasic Variation of the Inferior Vena Cava-Proof-of-Concept and Validation Against Transthoracic Echocardiography

BACKGROUND

In clinical practice, the right heart filling status is assessed using the respirophasic variation of the inferior vena cava (IVC) assessed by transthoracic echocardiography (TTE) showing moderate correlations with the catheter-based reference standard.

PURPOSE

To develop and validate a similar approach using MRI.

STUDY TYPE

Prospective.

POPULATION

37 male elite cyclists (mean age 26 ± 4 years).

FIELD STRENGTH/SEQUENCE

Real-time balanced steady-state free-precession cine sequence at 1.5 Tesla.

ASSESSMENT

Respirophasic variation included assessment of expiratory size of the upper hepatic part of the IVC and degree of inspiratory collapse expressed as collapsibility index (CI). The IVC was studied either in long-axis direction (TTE) or using two transverse slices, separated by 30 mm (MRI) during operator-guided deep breathing. For MRI, in addition to the TTE-like diameter, IVC area and major and minor axis diameters were also assessed, together with the corresponding CIs.

STATISTICAL TESTS

Repeated measures ANOVA test with Bonferroni correction. Intraclass correlation coefficient (ICC) and Bland-Altman analysis for intrareader and inter-reader agreement. A P value <0.05 was considered statistically significant.

RESULTS

No significant differences in expiratory IVC diameter were found between TTE and MRI, i.e., 25 ± 4 mm vs. 25 ± 3 mm (P = 0.242), but MRI showed a higher CI, i.e., 76% ± 14% vs. 66% ± 14% (P < 0.05). As the IVC presented a noncircular shape, i.e., major and minor expiratory diameter of 28 ± 4 mm and 21 ± 4 mm, respectively, the CI varied according to the orientation, i.e., 63% ± 27% vs. 75% ± 16%, respectively. Alternatively, expiratory IVC area was 4.3 ± 1.1 cm2 and showed a significantly higher CI, i.e., 86% ± 14% than diameter-based CI (P < 0.05). All participants showed a CI >50% with MRI versus 35/37 (94%) with TTE. ICC values ranged 0.546-0.841 for MRI and 0.545-0.704 for TTE.

CONCLUSION

Assessment of the respirophasic IVC variation is feasible with MRI. Adding this biomarker may be of particular use in evaluating heart failure patients.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 2.

Comparison of various surrogate markers for venous congestion in predicting acute kidney injury following cardiac surgery: A cohort study

BACKGROUND

Venous congestion has been demonstrated to increase the risk of acute kidney injury (AKI) after cardiac surgery. Although many surrogate markers for venous congestion are currently used in clinical settings, there is no consensus on which marker is most effective in predicting AKI.

METHODS

We evaluated various markers of venous congestion, including central venous pressure (CVP), inferior vena cava (IVC) diameter, portal pulsatility fraction (PPF), hepatic vein flow pattern (HVF), intra-renal venous flow pattern (IRVF), and venous excess ultrasound grading score (VExUS) in adult patients undergoing cardiac surgery to compare their ability in predicting AKI.

RESULTS

Among the 230 patients enrolled in our study, 53 (23.0%) developed AKI, and 11 (4.8%) required continuous renal replacement therapy (CRRT). Our multivariate logistic analysis revealed that IRVF, PPF, HVF, and CVP were significantly associated with AKI, with IRVF being the strongest predictor (odds ratio [OR] 2.27; 95% confidence interval [CI], 1.38-3.73). However, we did not observe any association between these markers and CRRT.

CONCLUSION

Venous congestion is associated with AKI after cardiac surgery, but not necessarily with CRRT. Among the markers tested, IRVF exhibits the strongest correlation with AKI.

Focused Cardiac Ultrasound Diagnosis of Dilated Cardiomyopathy

ABSTRACT

We report the case of a 6-year-old boy presenting to the emergency department after a syncopal event during a flu-like illness. Intermittent ventricular tachycardia was noted during Emergency Medical Services transport, and a focused cardiac ultrasound (FOCUS) in the emergency department revealed a dilated left ventricle and left atrium as well as severe global systolic dysfunction. Point-of-care ultrasound findings prompted expedited evaluation and management of this critically ill patient.

Is caval index a sufficient parameter for determining and monitoring dehydration in intoxication patients?

BACKGROUND

Cases of intoxication are increasing day by day and these patients are presenting to emergency departments. These patients are usually individuals with poor self-care, inadequate oral intake, and unable to meet their own needs, and may have significant dehydration due to the agents they have taken. The caval index (CI) is a recently used index to determine fluid requirement and response.

AIMS

We aimed to evaluate the success of CI in determining and monitoring dehydration in intoxication patients.

METHODS

Our study was conducted prospectively in the emergency department of a single tertiary care center. A total of ninety patients were included in the study. Caval index was calculated by measuring inspiratory and expiratory inferior vena cava diameters. Caval index measurements were repeated after 2 and 4 h.

RESULTS

Patients who were hospitalized, took multiple drugs, or needed inotropic agents had significantly higher caval index levels. A further increase in caval index levels was observed on second and third caval index evaluations in patients who received inotropic agents along with fluid resuscitation. Levels of systolic blood pressure recorded at admission (0. hour) showed a significant correlation with caval index and shock index. Caval index and the shock index were highly sensitive and specific at predicting mortality.

CONCLUSION

In our study, we found that CI can be used as an index to assist emergency clinicians in determining and monitoring fluid requirement in cases of intoxication presenting to the emergency department.

Closed thoracic drainage in elderly patients with chronic obstructive pulmonary disease complicated with spontaneous pneumothorax: A retrospective study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) combined with spontaneous pneumothorax, is characterized by significant decline in lung function, and even cause cardiopulmonary failure and hypoxia.

AIM

To evaluate the clinical effectiveness of central venous catheters and indwelling pleural catheters (IPC) in managing closed thoracic drainage in patients diagnosed with COPD with concomitant by spontaneous pneumothorax.

METHODS

Retrospective analysis was conducted on the clinical information of 60 elderly patients with COPD complicated by spontaneous pneumothorax admitted to the Shexian Branch of the second affiliated hospital of Zhejiang university school of medicine between March 2020 and March 2023. The clinical efficacy, complications, hospitalization duration, and costs were compared between patients with an indwelling thoracic catheter and those with a central venous catheter. Univariate logistic regression was used to analyze the causes of catheter displacement.

RESULTS

According to our findings, there were significant differences in the IPC group's clinical efficacy, catheter operation time, and lung recruitment time (P < 0.05). Comparing the complications after catheter treatment between the two groups revealed statistically significant variations in the incidence of postoperative analgesics, catheter abscission, catheter blockage, and subcutaneous emphysema in the IPC group (P < 0.05). Univariate analysis demonstrated significant differences between patients with and without catheter dislodgement regarding duty nurse's working years (less than three), Acute Physiology and Chronic Health Evaluation II (APACHE II) scores (less than 15), lack of catheter suture fixation, and the proportion of catheters not fixed twice (P < 0.05).

CONCLUSION

Our results demonstrated that when treating elderly COPD patients with spontaneous pneumothorax, indwelling thoracic catheters are more effective than the central venous catheter group. Patients' catheter shedding is influenced by the primary nurse's working years, APACHE II scores, and catheter fixation technique.

Safety and performance of a novel implantable sensor in the inferior vena cava under acute and chronic intravascular volume modulation

AIMS

The management of congestion is one of the key treatment targets in heart failure. Assessing congestion is, however, difficult. The purpose of this study was to investigate the safety and dynamic response of a novel, passive, inferior vena cava (IVC) sensor in a chronic ovine model.

METHODS AND RESULTS

A total of 20 sheep divided into three groups were studied in acute and chronic in vivo settings. Group I and Group II included 14 sheep in total with 12 sheep receiving the sensor and two sheep receiving a control device (IVC filter). Group III included an additional six animals for studying responses to volume challenges via infusion of blood and saline solutions. Deployment was 100% successful with all devices implanted; performing as expected with no device-related complications and signals were received at all observations. At similar volume states no significant differences in IVC area normalized to absolute area range were measured (55 ± 17% on day 0 and 62 ± 12% on day 120, p = 0.51). Chronically, the sensors were completely integrated with a thin, reendothelialized neointima with no loss of sensitivity to infused volume. Normalized IVC area changed significantly from 25 ± 17% to 43 ± 11% (p = 0.007) with 300 ml infused. In contrast, right atrial pressure required 1200 ml of infused volume prior to a statistically significant change from 3.1 ± 2.6 mmHg to 7.5 ± 2.0 mmHg (p = 0.02).

CONCLUSION

In conclusion, IVC area can be measured remotely in real-time using a safe, accurate, wireless, and chronic implantable sensor promising to detect congestion with higher sensitivity than filling pressures.

Non-Invasive Estimation of Right Atrial Pressure Using a Semi-Automated Echocardiographic Tool for Inferior Vena Cava Edge-Tracking

The non-invasive estimation of right atrial pressure (RAP) would be a key advancement in several clinical scenarios, in which the knowledge of central venous filling pressure is vital for patients’ management. The echocardiographic estimation of RAP proposed by Guidelines, based on inferior vena cava (IVC) size and respirophasic collapsibility, is exposed to operator and patient dependent variability. We propose novel methods, based on semi-automated edge-tracking of IVC size and cardiac collapsibility (cardiac caval index—CCI), tested in a monocentric retrospective cohort of patients undergoing echocardiography and right heart catheterization (RHC) within 24 h in condition of clinical and therapeutic stability (170 patients, age 64 ± 14, male 45%, with pulmonary arterial hypertension, heart failure, valvular heart disease, dyspnea, or other pathologies). IVC size and CCI were integrated with other standard echocardiographic features, selected by backward feature selection and included in a linear model (LM) and a support vector machine (SVM), which were cross-validated. Three RAP classes (low < 5 mmHg, intermediate 5−10 mmHg and high > 10 mmHg) were generated and RHC values used as comparator. LM and SVM showed a higher accuracy than Guidelines (63%, 71%, and 61% for LM, SVM, and Guidelines, respectively), promoting the integration of IVC and echocardiographic features for an improved non-invasive estimation of RAP.