Comparison of inferior vena cava collapsibility and central venous pressure in assessing volume status in shocked patients

Abnormal characteristics of inferior vena cava and abdominal aorta among neonates with early onset septic shock

BACKGROUND

The variety of shocks in neonates, if not recognized and treated immediately, is a major cause for fatality. The use of echocardiography may improve assessment and treatment, but its reference values across gestational age (GA) and birth weight (BW) are lacking. To address the information gap, this study aimed at correlating GA and BW of newborns with nonhemodynamic abnormalities, and at evaluating the usefulness of such reference values in neonates with early onset septic (EOS) -shock.

METHODS

A total of 200 normal newborns were enrolled as controls and subdivided into groups based on GA, BW, days of age, and patent ductus arteriosus (PDA). Echocardiography was used to document inferior vena cava diameter (IVC), inferior vena cava collapsibility index (IVC-CI), and inferior vena cava to abdominal aorta ratio (IVC/AO). In addition, 18 neonates with EOS shock were recruited and evaluated using echocardiography.

RESULTS

Among the control newborns, IVC and AO were significantly increased with GA and BW (P < 0.05) but IVC-CI and IVC/AO did not correlate with GA, BW, day of age, and PDA. Compared to the control group, the EOS-shock group had significantly decreased IVC and IVC/AO, and increased IVC-CI (P < 0.05). The cut-off values for indicating EOS-shock were > 34.15% for IVC-CI, < 47.58% for IVCmin/AO, and < 66.11% for IVCmax/AO.

CONCLUSIONS

The IVC-CI, IVCmin/AO, and IVCmax/AO indices are applicable to all neonates. Although the number of neonates with EOS-shock in our study is small, the cut-off values showed usefulness for diagnosis. Further research is needed to determine the application of the indices in a larger population and among other populations, especially for clinical application in treatment of shock among neonates.

Assessment of Fluid Responsiveness via Central Venous Ultrasound Measurement: A Network Meta-Analysis

Background: Ultrasonographic assessment of the diameters of various veins and their indices are among the most applied diagnostic tools for evaluating fluid responsiveness in clinical practice. Despite their widespread use, there is no definitive answer on which is preferable. Our study aimed to investigate the diagnostic accuracy of different venous diameters and their indices to assess fluid responsiveness. Methods: We conducted a systematic review and network meta-analysis, analyzing prospective studies evaluating the diagnostic accuracy of venous diameters (inferior vena cava [IVC], internal jugular vein [IJV], superior vena cava, and subclavian vena) and their indices for fluid responsiveness. Electronic databases were searched from inception until March 2024; this search was supplemented by snowballing methods. The risk of bias was evaluated with QUADAS-2, and evidence certainty was assessed using the GRADE approach. Nine prospective cohort studies (560 patients) were included. Results: The network meta-analysis revealed that the ΔCaval index exhibited a significant performance advantage over other "venous" test parameters. The caval index significantly outperformed IJV min/max and IVCmax. IJV index and IVCmin significantly outperformed IJVmin/max. The caval index was comparable to the IJV index. The caval index was comparable during mechanical ventilation and spontaneous breathing. Conclusions: In this meta-analysis, the ΔCaval index test showed higher diagnostic accuracy for fluid responsiveness compared with other venous tests. Caval and jugular indices displayed similar accuracy, and caval indices were consistent under mechanical ventilation and spontaneous breathing. Indices generally outperformed absolute values, except for IVCmin, which equaled the caval index in efficacy. This study was registered on the International Platform for Registered Protocols for Systematic Reviews and Meta-Analyses: INPLASY202430104.

Evaluation of the role of repeated inferior vena cava sonography in estimating first 24 h fluid requirement in resuscitation of major blunt trauma patients in emergency department Suez Canal University Hospital

INTRODUCTION

The assessment of hemodynamic status in polytrauma patients is an important principle of the primary survey of trauma patients, and screening for ongoing hemorrhage and assessing the efficacy of resuscitation is vital in avoiding preventable death and significant morbidity in these patients. Invasive procedures may lead to various complications and the IVC ultrasound measurements are increasingly recognized as a potential noninvasive replacement or a source of adjunct information.

AIMOF THIS STUDY

The study aimed to determine if repeated ultrasound assessment of the inferior vena cava (diameter, collapsibility (IVC- CI) in major trauma patients presenting with collapsible IVC before resuscitation and after the first hour of resuscitation will predict total intravenous fluid requirements at first 24 h.

PATIENTS & METHODS

The current study was conducted on 120 patients presented to the emergency department with Major blunt trauma (having significant injury to two or more ISS body regions or an ISS greater than 15). The patients(cases) group (shocked group) (60) patients with signs of shock such as decreased blood pressure < 90/60 mmHg or a more than 30% decrease from the baseline systolic pressure, heart rate > 100 b/m, cold, clammy skin, capillary refill > 2 s and their shock index above0.9. The control group (non-shocked group) (60) patients with normal blood pressure and heart rate, no other signs of shock (normal capillary refill, warm skin), and (shock index ≤ 0.9). Patients were evaluated at time 0 (baseline), 1 h after resucitation, and 24 h after 1st hour for:(blood pressure, pulse, RR, SO2, capillary refill time, MABP, IVCci, IVCmax, IVCmin).

RESULTS

Among 120 Major blunt trauma patients, 98 males (81.7%) and 22 females (18.3%) were included in this analysis; hypovolemic shocked patients (60 patients) were divided into two main groups according to IVC diameter after the first hour of resuscitation; IVC repleted were 32 patients (53.3%) while 28 patients (46.7%) were IVC non-repleted. In our study population, there were statistically significant differences between repleted and non-repleted IVC cases regarding IVCD, DIVC min, IVCCI (on arrival) (after 1 h) (after 24 h of 1st hour of resuscitation) ( p-value < 0.05) and DIVC Max (on arrival) (after 1 h) (p-value < 0.001). There is no statistically significant difference (p-value = 0.075) between repleted and non-repleted cases regarding DIVC Max (after 24 h).In our study, we found that IVCci0 at a cut-off point > 38.5 has a sensitivity of 80.0% and Specificity of 85.71% with AUC 0.971 and a good 95% CI (0.938 - 1.0), which means that IVCci of 38.6% or more can indicate fluid responsiveness. We also found that IVCci 1 h (after fluid resuscitation) at cut-off point > 28.6 has a sensitivity of 80.0% and Specificity of 75% with AUC 0.886 and good 95% CI (0.803 - 0.968), which means that IVCci of 28.5% or less can indicate fluid unresponsiveness after 1st hour of resuscitation. We found no statistically significant difference between repleted and non-repleted cases regarding fluid requirement and amount of blood transfusion at 1st hour of resuscitation (p-value = 0.104).

CONCLUSION

Repeated bedside ultrasonography of IVCD, and IVCci before and after the first hour of resuscitation could be an excellent reliable invasive tool that can be used in estimating the First 24 h of fluid requirement in Major blunt trauma patients and assessment of fluid status.

[Treatment of cardiogenic shock due to right ventricular involvement]

The right ventricle is susceptible to changes in preload, afterload, and contractility. The answer is its dilation with dysfunction/acute failure; filling is limited to the left ventricle and cardiac output. Systemic venous congestion is retrograde to the right heart, it is involved in the genesis of cardiogenic shock due to right ventricle involvement. This form of shock is less well known than that which occurs due to left ventricular failure, therefore, treatment may differ. Once the primary treatment has been carried out, since no response is obtained, supportive treatment aimed at ventricular pathophysiology will be the next option. It is suggested to evaluate the preload for the reasoned indication of liquids, diuretics or even ultrafiltration. Restore or maintain heart rate and sinus rhythm, treat symptomatic bradycardia, arrhythmias that make patients unstable, use of temporary pacing or cardioversion procedures. Improving contractility and vasomotility, using vasopressors and inotropes, alone or in combination, the objective will be to improve right coronary perfusion pressure. Balance the effect of drugs and maneuvers on preload and/or afterload, such as mechanical ventilation, atrial septostomy and pulmonary vasodilators. And the increasing utility of mechanical support of the circulation that has become a useful tool to preserve/restore right heart function.

The Role of Ultrasonographic Inferior Vena Cava Measurement in the Volume-Based Classification of Patients With Hyponatremia

OBJECTIVES

To demonstrate the role of inferior vena cava (IVC) collapsibility in the assessment of volume status in hyponatremic critically ill patients in the emergency department (ED) with bedside IVC imaging and to predict volume status with response to fluid therapy.

METHODS

A prospective 110 hypotonic hyponatremic patients aged >18 years with a serum sodium level under 125 mEq/L and at least one symptom of hyponatremia, who presented or referred to the ED was conducted. Demographical, clinical, and laboratory characteristics with bedside measurement of IVC diameter of patients were recorded. Volume status was divided into 3 subgroups: hypovolemic-G1, euvolemic-G2, and hypervolemic-G3. An ED trainee with a certification to perform basic and advanced ultrasonography (USG) training carried out the USG examinations. A diagnostic algorithm approach was made according to the results.

RESULTS

Symptom severity was significantly greater in the hypervolemic group than the other groups (P = .009 and P = .034, respectively). Systolic blood pressure (SBP) and mean arterial pressure (MAP) were significantly lower in the hypovolemic group compared with the other groups (P < .001 and P = .003, respectively). There was a significant difference between the ultrasonographically measured IVC min, IVC max, and mean IVC values across the three volume-based groups (P < .001).

CONCLUSION

Considering the diversity of physical examination (PE) findings, with the highly heterogenous nature of hyponatremia, a new measurable algorithm can be developed on the basis of contemporary hyponatremic patient management guidelines.

Assessing the Efficacy of Inferior Vena Cava Collapsibility Index for Predicting Hypotension after Central Neuraxial Block: A Systematic Review and Meta-Analysis

The use of ultrasonography to predict spinal-induced hypotension (SIH) has gained significant attention. This diagnostic meta-analysis aimed to investigate the reliability of the inferior vena cava collapsibility index (IVCCI) in predicting SIH in patients undergoing various surgeries. Databases, including Embase, Cochrane Library, Medline, and Google Scholar, were screened until 28 July 2023, yielding 12 studies with 1076 patients (age range: 25.6-79 years) undergoing cesarean section (CS) (n = 4) or non-CS surgeries (n = 8). Patients with SIH had a significantly higher IVCCI than those without SIH (mean difference: 11.12%, 95% confidence interval (CI): 7.83-14.41). The pooled incidence rate of SIH was 40.5%. IVCCI demonstrated satisfactory overall diagnostic reliability (sensitivity, 77%; specificity, 82%). The pooled area under the curve (AUC) was 0.85, indicating its high capability to differentiate patients at risk of PSH. The Fagan nomogram plot demonstrated a positive likelihood ratio (PLR) of 4 and a negative likelihood ratio (NLR) of 0.28. The results underscore the robustness and discriminative ability of IVCCI as a predictive tool for SIH. Nevertheless, future investigations should focus on assessing its applicability to high-risk patients and exploring the potential enhancement in patient safety through its incorporation into clinical practice.

Central Venous Waveform Analysis and Cardiac Output in a Porcine Model of Endotoxemic Hypotension and Resuscitation

BACKGROUND

Cardiac output (CO) is a valuable proxy for perfusion, and governs volume responsiveness during resuscitation from distributive shock. The underappreciated venous system has nuanced physiology that confers valuable hemodynamic information. In this investigation, deconvolution of the central venous waveform by the fast Fourier transformation (FFT) algorithm is performed to assess its ability to constitute a CO surrogate in a porcine model of endotoxemia-induced distributive hypotension and resuscitation.

STUDY DESIGN

Ten pigs were anesthetized, catheterized, and intubated. A lipopolysaccharides infusion protocol was used to precipitate low systemic vascular resistance hypotension. Four crystalloid boluses (10 cc/kg) were then given in succession, after which heart rate, mean arterial pressure, thermodilution-derived CO, central venous pressure (CVP), and the central venous waveform were collected, the last undergoing fast Fourier transformation analysis. The amplitude of the fundamental frequency of the central venous waveform's cardiac wave (f0-CVP) was obtained. Heart rate, mean arterial pressure, CVP, f0-CVP, and CO were plotted over the course of the boluses to determine whether f0-CVP tracked with CO better than the vital signs, or than CVP itself.

RESULTS

Distributive hypotension to a 25% mean arterial pressure decrement was achieved, with decreased systemic vascular resistance (mean 918 ± 227 [SD] dyne/s/cm-5 vs 685 ± 180 dyne/s/cm-5; p = 0.038). Full hemodynamic parameters characterizing this model were reported. Slopes of linear regression lines of heart rate, mean arterial pressure, CVP, f0-CVP, and CO were -2.8, 1.7, 1.8, 0.40, and 0.35, respectively, demonstrating that f0-CVP values closely track with CO over the 4-bolus range.

CONCLUSIONS

Fast Fourier transformation analysis of the central venous waveform may allow real-time assessment of CO during resuscitation from distributive hypotension, possibly offering a venous-based approach to clinical estimation of volume responsiveness.