Rapid Ultrasound in Shock (RUSH) Velocity-Time Integral: A Proposal to Expand the RUSH Protocol

Hepatocardiorenal Syndrome: Integrating Pathophysiology with Clinical Decision-Making via Point-Of-Care Ultrasound

BACKGROUND

Accumulating evidence has challenged the traditional model of the liver-kidney connection in hepatorenal syndrome. Cirrhosis can significantly impact cardiac function, leading to cirrhotic cardiomyopathy. Recent understanding reveals how cardiac dysfunction plays a pivotal role in the development of renal dysfunction in this setting, suggesting that disturbances traditionally categorized under hepatorenal syndrome may actually represent a hepatic form of cardiorenal syndrome - hepatocardiorenal syndrome - where the liver affects the kidney through cardiorenal pathways.

SUMMARY

Effective management of hepatocardiorenal syndrome and acute kidney injury in cirrhosis relies on accurately assessing a patient's hemodynamic and volume status. Point-of-care ultrasound, including lung and focused cardiac ultrasound, is a valuable diagnostic tool that provides crucial data on fluid tolerance, subclinical pulmonary congestion, and left ventricular filling pressures. This objective, bedside approach offers a comprehensive assessment that directly influences patient management and therapeutic decisions.

KEY MESSAGES

Point-of-care ultrasound plays an essential role in evaluating and managing hepatocardiorenal syndrome, providing insights into the underlying pathophysiology. By assessing hemodynamic parameters, it helps guide therapy and monitor patient responses, ensuring more accurate and effective treatment of patients with cirrhosis and acute kidney injury.

The Left Ventricular Outflow Tract Velocity Time Integral as a Predictor of Fluid Responsiveness in Patients With Sepsis-Related Acute Circulatory Failure

BACKGROUND

Sepsis is a major contributor to global morbidity and mortality. Effective fluid resuscitation is essential for managing septic shock, but it must be carefully monitored to avoid fluid overload and related complications. Recent studies have demonstrated that both inadequate and excessive fluid resuscitation are linked to poor outcomes.

METHODS

This observational study was conducted over 18 months, including spontaneously breathing patients aged 18 to 65 with sepsis-related acute circulatory failure. Patients were enrolled through convenience sampling. Baseline vital signs and point-of-care ultrasound (POCUS) parameters were recorded. A volume expansion test (VET) was performed, administering 500 ml of normal saline over 15 minutes, followed by reassessment of vital signs and POCUS parameters. Patients were classified as responders or non-responders. The study evaluated the left ventricular outflow tract velocity time integral (LVOT VTI) as a predictor of fluid responsiveness.

RESULTS

The study enrolled 113 patients with a mean age of 48.69 years (SD: ±16.81). The most common age group was 61-70 years (24 patients; 21.2%), and there was a male predominance (73 patients; 64.6%). Forty-eight patients (42.5%) had no comorbidities, with hypertension being the most prevalent (17 patients; 15.0%). Pneumonia was the most common source of sepsis (50 patients; 44.2%), and 16 patients (14.2%) died. The percentage change in LVOT VTI following the VET demonstrated a sensitivity of 96.0% and specificity of 100%, with an area under the receiver operating characteristic (ROC) curve of 0.992. A percentage change of ≥15.19% indicated high fluid responsiveness, although a single VTI measurement alone was not a reliable predictor.

CONCLUSION

LVOT VTI measurements play a critical role in assessing fluid responsiveness in sepsis-related acute circulatory failure. While a single VTI measurement is unreliable, the percentage change in LVOT VTI after a VET offers excellent diagnostic performance. A cutoff of ≥15.19% post-expansion indicates a high likelihood of fluid responsiveness.

Assessment of change in end-tidal CO2 after fluid challenge as a marker of fluid responsiveness as measured by the aortic velocity time integral in healthy anesthetized mechanically ventilated dogs

OBJECTIVE

To evaluate if variation in the end-tidal CO2 partial pressure (∆Petco2) after a fluid challenge could predict fluid responsiveness with a sensitivity of 75% and a specificity of 70% in healthy anesthetized and mechanically ventilated dogs.

DESIGN

Diagnostic accuracy study.

SETTING

University hospital.

ANIMALS

Twenty-seven dogs admitted for neutering.

INTERVENTIONS

To obtain a balanced sample between fluid responder and nonresponder dogs, a 10-mL/kg lactated Ringer's solution was administered over 15 minutes to half of the population before the baseline measurements. All animals then received a fluid challenge of 10 mL/kg lactated Ringer's solution in 5 minutes.

MEASUREMENTS AND MAIN RESULTS

The velocity-time integral of aortic blood flow (VTIAo) was evaluated with Doppler echocardiography before and after a fluid challenge to classify the included dogs as fluid responders or nonresponders. Fluid responsiveness was defined as an increase of ≥15% of the VTIAo after the fluid challenge. Petco2 was evaluated at 1, 5, and 10 (T1, T5, T10) minutes after fluid expansion. Area under the receiver operating characteristic curve (AUROC) analysis was used to assess the ability of ∆Petco2 to predict fluid responsiveness at different time points. A total of 13 dogs were fluid responders, and 14 were nonresponders. The best predictive capacity for ∆Petco2 was observed at T10. The AUROC with its 95% confidence interval (CI) for ∆Petco2 at T10 was 0.75 (0.56-0.93), with a sensitivity of 84.62% (95% CI, 54.60-98.10), a specificity of 64.29% (95% CI, 35.10-87.20), a positive predictive value of 68.80% (95% CI, 41.30-89.00), and a negative predictive value of 81.80% (95% CI, 48.20-97.70). The optimal cutoff was 1 mm Hg.

CONCLUSIONS

The current study showed that, although minimal, ∆Petco2 predicted fluid responsiveness in the dogs studied.

Automated and reference methods for the calculation of left ventricular outflow tract velocity time integral or ejection fraction by non-cardiologists: a systematic review on the agreement of the two methods

Echocardiography is crucial for evaluating patients at risk of clinical deterioration. Left ventricular ejection fraction (LVEF) and velocity time integral (VTI) aid in diagnosing shock, but bedside calculations can be time-consuming and prone to variability. Artificial intelligence technology shows promise in providing assistance to clinicians performing point-of-care echocardiography. We conducted a systematic review, utilizing a comprehensive literature search on PubMed, to evaluate the interchangeability of LVEF and/or VTI measurements obtained through automated mode as compared to the echocardiographic reference methods in non-cardiology settings, e.g., Simpson´s method (LVEF) or manual trace (VTI). Eight studies were included, four studying automated-LVEF, three automated-VTI, and one both. When reported, the feasibility of automated measurements ranged from 78.4 to 93.3%. The automated-LVEF had a mean bias ranging from 0 to 2.9% for experienced operators and from 0% to -10.2% for non-experienced ones, but in both cases, with wide limits of agreement (LoA). For the automated-VTI, the mean bias ranged between - 1.7 cm and - 1.9 cm. The correlation between automated and reference methods for automated-LVEF ranged between 0.63 and 0.86 for experienced and between 0.56 and 0.81 for non-experienced operators. Only one study reported a correlation between automated-VTI and manual VTI (0.86 for experienced and 0.79 for non-experienced operators). We found limited studies reporting the interchangeability of automated LVEF or VTI measurements versus a reference approach. The accuracy and precision of these automated methods should be considered within the clinical context and decision-making. Such variability could be acceptable, especially in the hands of trained operators. PROSPERO number CRD42024564868.

Verification Study of In Silico Computed Intracardiac Blood Flow With 4D Flow MRI

OBJECTIVE

Major challenges for clinical applications of in silico medicine are limitations in time and computational resources. Computational approaches should therefore be tailored to specific applications with relatively low complexity and must be verified and validated against clinical gold standards.

METHODS

This study performed computational fluid dynamics simulations of left ventricular hemodynamics of different complexity based on shape reconstruction from steady state gradient echo magnetic resonance imaging (MRI) data. Computed flow results of a rigid wall model (RWM) and a prescribed motion fluid-structure interaction (PM-FSI) model were compared against phase-contrast MRI measurements for three healthy subjects.

RESULTS

Extracted boundary conditions from the steady state MRI sequences as well as computed metrics, such as flow rate, valve velocities, and kinetic energy show good agreement with in vivo flow measurements. Regional flow analysis reveals larger differences.

CONCLUSION

Basic flow structures are well captured with RWM and PM-FSI. For the computation of further biomarkers like washout or flow efficiency, usage of PM-FSI is required. Regarding boundary-near flow, more accurate anatomical models are inevitable.

SIGNIFICANCE

These results delineate areas of application of both methods and lay a foundation for larger validation studies and sensitivity analysis for healthy and diseased cases, being an essential step upon clinical translations.

Guidance for performance, utilization, and education of cardiac and lung point-of-care ultrasonography from the Japanese Society of Echocardiography

In recent years, bedside ultrasound examinations have been used in many clinical departments and are called point-of-care ultrasound (POCUS). Regarding POCUS in the cardiac field, a protocol called focus (focused) cardiac ultrasound (FoCUS) has been developed in Europe and the United States, is being used clinically, and an educational syllabus has been created. According to them, FoCUS is defined as a point-of-care cardiac ultrasound examination using standardized limited sections and protocols. FoCUS is primarily intended to be performed by non-cardiologists, and in order to avoid making mistakes in judgment, it is important to be familiar with its limitations and it is necessary to understand pathological conditions that can only be diagnosed using conventional comprehensive echocardiography. The Japanese Society of Echocardiography has edited this clinical guideline because we believe that FoCUS should be used effectively and appropriately in Japan, and that appropriate education is essential to popularize FoCUS in Japan. Furthermore, lung POCUS has recently come into clinical use. Lung POCUS is useful for the diagnosis and follow-up of heart failure when used in conjunction with FoCUS, and is especially useful in primary care where chest X-rays are not available. The working group that created this manual agreed that it is desirable to educate patients about lung POCUS in conjunction with FoCUS, so we decided to include the basic techniques of lung POCUS and how to use them in this manuscript.

Point-of-care ultrasonography in cirrhosis-related acute kidney injury: How I do it

Discerning the etiology of acute kidney injury (AKI) in cirrhotic patients remains a formidable challenge due to diverse and overlapping causes. The conventional approach of empiric albumin administration for suspected volume depletion may inadvertently lead to fluid overload. In the recent past, point-of-care ultrasonography (POCUS) has emerged as a valuable adjunct to clinical assessment, offering advantages in terms of diagnostic accuracy, rapidity, cost-effectiveness, and patient satisfaction. This review provides insights into the strategic use of POCUS in evaluating cirrhotic patients with AKI. The review distinguishes basic and advanced POCUS, emphasizing a 5-point basic POCUS protocol for efficient assessment. This protocol includes evaluations of the kidneys and urinary bladder for obstructive nephropathy, lung ultrasound for detecting extravascular lung water, inferior vena cava (IVC) ultrasound for estimating right atrial pressure, internal jugular vein ultrasound as an alternative to IVC assessment, and focused cardiac ultrasound for assessing left ventricular (LV) systolic function and identifying potential causes of a plethoric IVC. Advanced POCUS delves into additional Doppler parameters, including stroke volume and cardiac output, LV filling pressures and venous congestion assessment to diagnose or prevent iatrogenic fluid overload. POCUS, when employed judiciously, enhances the diagnostic precision in evaluating AKI in cirrhotic patients, guiding appropriate therapeutic interventions, and minimizing the risk of fluid-related complications.

Inferior vena cava collapsibility index and stroke volume as predictors of blood transfusion in upper gastrointestinal bleeding in the emergency department

BACKGROUND AND AIM

This study investigates the effectiveness of bedside ultrasonography in predicting blood transfusion requirements in patients with upper gastrointestinal bleeding (UGIB). It focuses on evaluating the inferior vena cava (IVC) diameter, IVC collapsibility index (CI), and stroke volume (SV) as ultrasonographic measures.

METHODS

A hundred adult patients enrolled in this prospective clinical study. The patients were divided into two groups (group 1: only saline administered group, group 2: saline and blood administered group). IVC diameter, IVC CI, and SV were measured at the time of admission and after treatment.

RESULTS

At the initial admission, group 1 exhibited an IVC CI of 20.4% and an SV of 65.0 mL, whereas group 2 displayed an IVC CI of 26.6% and an SV of 58.0 mL. Upon analyzing the relationship between the Glasgow-Blatchford score (GBS) and SV, we identified a significant negative correlation (r = -0.7350; P < 0.001). Similarly, a weak negative correlation was observed between the Rockall score (RS) and SV (r = -0.4718; P < 0.001). It is worth noting that patients with UGIB require blood transfusion if their SV falls below 62.5 mL, with an area under the curve (AUC) of 89.1% and a 95% confidence interval (CI) ranging from 82.8% to 95.4%.

CONCLUSION

IVC CI and SV can be used as parameters to predict the need for blood transfusion in the ED in patients with UGIB.

Dynamic changes of hepatic vein Doppler velocities predict preload responsiveness in mechanically ventilated critically ill patients

BACKGROUND

Assessment of dynamic parameters to guide fluid administration is one of the mainstays of current resuscitation strategies. Each test has its own limitations, but passive leg raising (PLR) has emerged as one of the most versatile preload responsiveness tests. However, it requires real-time cardiac output (CO) measurement either through advanced monitoring devices, which are not routinely available, or echocardiography, which is not always feasible. Analysis of the hepatic vein Doppler waveform change, a simpler ultrasound-based assessment, during a dynamic test such as PLR could be useful in predicting preload responsiveness. The objective of this study was to assess the diagnostic accuracy of hepatic vein Doppler S and D-wave velocities during PLR as a predictor of preload responsiveness.

METHODS

Prospective observational study conducted in two medical-surgical ICUs in Chile. Patients in circulatory failure and connected to controlled mechanical ventilation were included from August to December 2023. A baseline ultrasound assessment of cardiac function was performed. Then, simultaneously, ultrasound measurements of hepatic vein Doppler S and D waves and cardiac output by continuous pulse contour analysis device were performed during a PLR maneuver.

RESULTS

Thirty-seven patients were analyzed. 63% of the patients were preload responsive defined by a 10% increase in CO after passive leg raising. A 20% increase in the maximum S wave velocity after PLR showed the best diagnostic accuracy with a sensitivity of 69.6% (49.1-84.4) and specificity of 92.8 (68.5-99.6) to detect preload responsiveness, with an area under curve of receiving operator characteristic (AUC-ROC) of 0.82 ± 0.07 (p = 0.001 vs. AUC-ROC of 0.5). D-wave velocities showed worse diagnostic accuracy.

CONCLUSIONS

Hepatic vein Doppler assessment emerges as a novel complementary technique with adequate predictive capacity to identify preload responsiveness in patients in mechanical ventilation and circulatory failure. This technique could become valuable in scenarios of basic hemodynamic monitoring and when echocardiography is not feasible. Future studies should confirm these results.

Evaluation of parameters used in echocardiography and ultrasound protocol for the diagnosis of shock etiology in emergency setting

BACKGROUND

Early recognition and appropriate treatment has shown to decrease morbidity and mortality in patients with undifferentiated shock. There are many ultrasound protocols in shock; each protocol combines core ultrasound elements such as IVC and cardiac assessment which includes detection of cardiac tamponade, left ventricular function and right ventricular strain.Valvular assessment is absent in majority of ultasound protocols, while lung ultrasound is included in some of them.

OBJECTIVE

In this study we investigated which parameters used in Echo - US protocol help differentiate shock types.

METHODS

This cross sectional study was conducted on 150 patients with shock (140 patients were included while, 10 patients were excluded).Sensitivity and specificity of different parameters used in the Echo-US protocol were analyzed to detect which parameters can diffentiate shock types.

RESULTS

Velocity time integral of Aorta and IVC maximum diameter were good discriminators for distributive shock, with area under the ROC curve (AUC) = 0.8885 (95% CI 0.8144 to 0.9406) and 0.7728 (95% CI 0.6832 to 0.8473) (Z = 10.256 p < 0.0001) and (Z = 5.079 p < 0.0001) respectively. Left ventricular systolic function, presence of pneumonia, pneumothorax or valve vegetations were of great value in differentiating shock types, while CUST, FAST, TAPSE and RV diameter were not useful in differentiating shock types.

CONCLUSION

Ultrasound and echocardiography are powerful tools that can be used to identify shock etiology when the clinical picture overlaps.

Maternal circulating miRNAs contribute to negative pregnancy outcomes by altering placental transcriptome and fetal vascular dynamics

Circulating miRNAs the in blood are promising biomarkers for predicting pregnancy complications and adverse birth outcomes. Previous work identified 11 gestationally elevated maternal circulating miRNAs (HEamiRNAs) that predicted infant growth deficits following prenatal alcohol exposure and regulated epithelial-mesenchymal transition in the placenta. Here we show that a single intravascular administration of pooled murine-conserved HEamiRNAs to pregnant mice on gestational day 10 (GD10) attenuates umbilical cord blood flow during gestation, explaining the observed intrauterine growth restriction (IUGR), specifically decreased fetal weight, and morphometric indices of cranial growth. Moreover, RNAseq of the fetal portion of the placenta demonstrated that this single exposure has lasting transcriptomic changes, including upregulation of members of the Notch pathway (Dll4, Rfng, Hey1), which is a pathway important for trophoblast migration and differentiation. Weighted gene co-expression network analysis also identified chemokine signaling, which is responsible for regulating immune cell-mediated angiogenesis in the placenta, as an important predictor of fetal growth and head size. Our data suggest that HEamiRNAs perturb the expression of placental genes relevant for angiogenesis, resulting in impaired umbilical cord blood flow and subsequently, IUGR.

Correlation of Common Carotid Artery Blood Flow Parameters With Transthoracic Echocardiographic Cardiac Output for Assessing Fluid Responsiveness After Passive Leg Raising (PLR) Test in Critically Ill Patients

Introduction The passive leg raising (PLR) test is a simple, non-invasive method of knowing fluid responsiveness by acting as an internal-fluid challenge. The PLR test coupled with a non-invasive assessment of stroke volume would be the ideal method to assess fluid responsiveness. This study aimed to determine the correlation between transthoracic echocardiographic cardiac output (TTE-CO) and common carotid artery blood flow (CCABF) parameters in determining fluid responsiveness with the PLR test. Methods  We performed a prospective observational study on 40 critically ill patients. Patients were evaluated with a 7-13 MHz linear transducer probe for CCABF parameters calculated using time-averaged mean velocity (TAmean) and with a 1-5 MHz cardiac probe equipped with tissue doppler imaging (TDI) for TTE-CO calculated using left ventricular outflow tract velocity time integral (LVOT VTI) with an apical five-chamber view. Two separate PLR tests (five minutes apart) were done within 48 hours of ICU admission. The first PLR test was to assess the effects on TTE-CO. The second PLR test was performed to assess the effects on CCABF parameters. Patients were designated as fluid responders (FR) if changes in TTE-CO (Δ TTE-CO) ≥ 10 %. Results  A positive PLR test was observed in 33% of patients. A strong correlation was present between absolute values of TTE-CO calculated using LVOT VTI and the absolute values of CCABF calculated using TAmean (r=0.60, p<0.05). However, a weak correlation was found between Δ TTE-CO and changes in CCABF (Δ CCABF) during the PLR test (r=0.05, p<0.74). A positive PLR test response could not be detected by Δ CCABF (area under the curve (AUC): 0.59 ± 0.09). Conclusions We found a moderate correlation between TTE-CO and CCABF at baseline. However, Δ TTE-CO had a very poor correlation with Δ CCABF, during the PLR test. Considering this, CCABF parameters may not be recommended as a means to detect fluid responsiveness with PLR tests in critically ill patients.

End-tidal carbon dioxide's change to fluid challenge versus internal jugular vein dispensability index for predicting fluid responsiveness in septic patients: A prospective, observational study

Background and Aims

The prediction of fluid responsiveness is crucial for the fluid management of septic shock patients. This prospective, observational study was conducted to compare end-tidal carbon dioxide (ETCO2) change due to fluid challenge (FC-induced ΔETCO2) versus internal jugular vein distensibility index (IJVDI) as predictors of fluid responsiveness in such patients.

Methods

Septic hypoperfused mechanically ventilated patients were classified as fluid responders (Rs) and non-responders (NRs) according to the improvement of left ventricular outflow tract-velocity time integral (ΔLVOT-VTI) after fluid challenge (FC). The receiver operating characteristic (ROC) curves of FC-induced ΔETCO2, pre-(FC) IJVDI and their combination for prediction of fluid responsiveness were compared to that of ΔLVOT-VTI% as a gold standard.

Results

Of 140 patients who completed the study, 51 (36.4%) patients were classified as Rs and 89 (63.6%) patients as NRs. With regard to the prediction of fluid responsiveness, no significant difference (P. 0. 384) was found between the diagnostic accuracy of FC-induced ΔETCO2 >2 mmHg (area under the ROC curve [AUC] 0.908, P < 0.001) and that of pre-(FC) IJVDI >18% (AUC 0.938, P < 0.001), but a prediction model combining both markers, ΔETCO2 ≥3 mmHg and IJVDI ≥16%, achieved significantly higher accuracy (AUC 0.982, P < 0.001) than each independent one (P < 0.05).

Conclusion

Under stable ventilatory and metabolic conditions, the predictivity of FC-induced ΔETCO2 >2 mmHg can be comparable to that of pre-(FC) IJVDI >18%. A predictive model combining both FC-induced ΔETCO2 ≥3 mmHg and IJVDI ≥16% can provide higher accuracy than that recorded for each one independently.

Intra-and inter-observer variability of point of care ultrasound measurements to evaluate hemodynamic parameters in healthy volunteers

BACKGROUND

Point-of-care ultrasound (POCUS) is a valuable tool for assessing the hemodynamic status of acute patients. Even though POCUS often uses a qualitative approach, quantitative measurements have potential advantages in evaluating hemodynamic status. Several quantitative ultrasound parameters can be used to assess the hemodynamic status and cardiac function. However, only limited data on the feasibility and reliability of the quantitative hemodynamic measurements in the point-of-care setting are available. This study investigated the intra- and inter-observer variability of PoCUS measurements of quantitative hemodynamic parameters in healthy volunteers.

METHODS

In this prospective observational study, three sonographers performed three repeated measurements of eight different hemodynamic parameters in healthy subjects. An expert panel of two experienced sonographers evaluated the images' quality. The repeatability (intra-observer variability) was determined by calculating the coefficient of variation (CV) between the separate measurements for each observer. The reproducibility (inter-observer variability) was assessed by determining the intra-class correlation coefficient (ICC).

RESULTS

32 subjects were included in this study, on whom, in total, 1502 images were obtained for analysis. All parameters were in a normal physiological range. Stroke volume (SV), cardiac output (CO), and inferior vena cava diameter (IVC-D) showed high repeatability (CV under 10%) and substantial reproducibility (ICC 0.61-0.80). The other parameters had only moderate repeatability and reproducibility.

CONCLUSIONS

We demonstrated good inter-observer reproducibility and good intra-observer repeatability for CO, SV and IVC-D taken in healthy subjects by emergency care physicians.

Improving echographic monitoring of hemodynamics in critically ill patients: Validation of right cardiac output measurements through the modified subcostal window

OBJECTIVE

We aimed to assess the usefulness of using the right ventricle outflow tract (RVOT) velocity-time integral (VTI) for echocardiographic monitoring of cardiac output compared to the gold standard, the VTI along the left ventricle outflow tract (LVOT).

DESIGN

Prospective observational study.

SETTING

A tertiary intensive care unit.

PATIENTS

100 consecutive patients.

INTERVENTIONS

echocardiographic monitoring in critically ill patients.

MAIN VARIABLES OF INTEREST

We used intraclass correlation coefficients (ICC) to compare echocardiographic measurements of LVOT VTI through apical window with RVOT VTI through the parasternal and modified subcostal windows and to assess interobserver reproducibility. Preplanned post hoc analyses compared the ICC between ventilated and nonventilated patients.

RESULTS

At the time of echocardiography, 44 (44%) patients were mechanically ventilated and 28 (28%) were receiving vasoactive drugs. Good-quality measurements were obtained through the parasternal short-axis and/or apical views in 81 (81%) patients and in 100 (100%) patients through the subcostal window. Consistency with LVOT VTI was moderate for RVOT VTI measured from the modified subcostal view (ICC 0.727; 95%CI: 0.62-0.808) and for RVOT VTI measured from the transthoracic view (0.715; 95%CI: 0.59-0.807).

CONCLUSIONS

Measurements of RVOT VTI are moderately consistent with measurements of LVOT VTI. Adding the modified subcostal window allows monitoring RVOT VTI in all the patients of this selected cohort, even those under mechanical ventilation.

Point-of-Care Ultrasound: A Moving Picture Is Worth a Thousand Tests

The effective utilization of point-of-care ultrasound may decrease the utilization of conventional diagnostic modalities. This review describes the various pathologies that can be effectively and rapidly identified with point-of-care cardiac, lung, abdominal, vascular airway, and ocular ultrasonography.

Renal arterial resistive index, monocyte chemotactic protein 1 and neutrophil gelatinase-associated lipocalin, for predicting acute kidney injury in critically ill cancer patients

PURPOSE

We evaluated the renal arterial resistive index (RRI), urine monocyte chemotactic protein 1 (uMCP-1), and urine neutrophil gelatinase-associated lipocalin (uNGAL) to predict acute kidney injury (AKI) in critically ill cancer patients.

METHODS

In this prospective study, we included patients without AKI. We compared the area under the curve (AUC) of RRI, uMCP-1, and uNGAL to predict any stage of AKI and stage-3 AKI with the DeLong method, and we established cutoff points with the Youden index.

RESULTS

We included 64 patients, and 43 (67.2%) developed AKI. The AUC to predict AKI were: 0.714 (95% CI 0.587-0.820) for the RRI, 0.656 (95% CI 0.526-0.770) for uMCP-1, and 0.677 (95% CI 0.549-0.789) for uNGAL. The AUC to predict stage-3 AKI were: 0.740 (95% CI 0.615-0.842) for the RRI, 0.757 (95% CI 0.633-0.855) for uMCP-1, and 0.817 (95% CI 0.701-0.903) for uNGAL, without statistical differences among them. For stage 3 AKI prediction, the sensitivity and specificity were: 56.3% and 87.5% for a RRI > 0.705; 70% and 79.2% for an uMCP-1 > 2169 ng/mL; and 87.5% and 70.8% for a uNGAL > 200 ng/mL. The RRI was significantly correlated to age (r = 0.280), estimated glomerular filtration rate (r = - 0.259), mean arterial pressure (r = - 0.357), and serum lactate (r = 0.276).

CONCLUSION

The RRI, uMCP-1, and uNGAL have a similar ability to predict AKI. The RRI is more specific, while urine biomarkers are more sensitive to predict stage 3 AKI. The RRI correlates with hemodynamic variables. The novel uMCP-1 could be a useful biomarker that needs to be extensively studied.

Measuring the accuracy of cardiac output using POCUS: the introduction of artificial intelligence into routine care

Background

Shock management requires quick and reliable means to monitor the hemodynamic effects of fluid resuscitation. Point-of-care ultrasound (POCUS) is a relatively quick and non-invasive imaging technique capable of capturing cardiac output (CO) variations in acute settings. However, POCUS is plagued by variable operator skill and interpretation. Artificial intelligence may assist healthcare professionals obtain more objective and precise measurements during ultrasound imaging, thus increasing usability among users with varying experience. In this feasibility study, we compared the performance of novice POCUS users in measuring CO with manual techniques to a novel automation-assisted technique that provides real-time feedback to correct image acquisition for optimal aortic outflow velocity measurement.

Methods

28 junior critical care trainees with limited experience in POCUS performed manual and automation-assisted CO measurements on a single healthy volunteer. CO measurements were obtained using left ventricular outflow tract (LVOT) velocity time integral (VTI) and LVOT diameter. Measurements obtained by study subjects were compared to those taken by board-certified echocardiographers. Comparative analyses were performed using Spearman’s rank correlation and Bland–Altman matched-pairs analysis.

Results

Adequate image acquisition was 100% feasible. The correlation between manual and automated VTI values was not significant (p = 0.11) and means from both groups underestimated the mean values obtained by board-certified echocardiographers. Automated measurements of VTI in the trainee cohort were found to have more reproducibility, narrower measurement range (6.2 vs. 10.3 cm), and reduced standard deviation (1.98 vs. 2.33 cm) compared to manual measurements. The coefficient of variation across raters was 11.5%, 13.6% and 15.4% for board-certified echocardiographers, automated, and manual VTI tracing, respectively.

Conclusions

Our study demonstrates that novel automation-assisted VTI is feasible and can decrease variability while increasing precision in CO measurement. These results support the use of artificial intelligence-augmented image acquisition in routine critical care ultrasound and may have a role for evaluating the response of CO to hemodynamic interventions. Further investigations into artificial intelligence-assisted ultrasound systems in clinical settings are warranted.

Measurement of Cardiac Output by Point-of-Care Transthoracic Echocardiography

Traditionally measured with invasive methods or specialized equipment, stroke volume and cardiac output can be determined reliably with transthoracic echocardiography. This video guides the viewer in a step-by-step fashion through the technical aspects of Doppler echocardiographic assessment of cardiac output.

Diploma on Basic Echocardiography training and competencies for Intensive Care and Emergency medicine: Consensus document of the Spanish Society of Anesthesiology and Critical Care (SEDAR) and the Spanish Society of Emergency Medicine (SEMES)

Cardiac ultrasound has become an essential tool for diagnosis and hemodynamic monitoring in critically ill patients. Scientific societies need to work toward developing a training program that will allow clinicians to acquire competence in performing cardiac ultrasound and understanding its indications. The Clinical Ultrasound for Intensive Care task force of the Spanish Society of Anesthesiology and Critical Care (SEDAR) and the Spanish Society of Emergency Medicine (SEMES) have drawn up this position statement defining the learning objectives and training required to acquire the competencies recommended for basic ultrasound management in the intensive care and emergency setting in order to obtain a diploma in Basic Ultrasound in Intensive Care and Emergency Medicine. This document defines the training program and the competencies needed for basic skills in ultrasound in Intensive Care and Emergency Medicine-part of the Diploma in Ultrasound for Intensive Care and Emergency Medicine awarded by SEDAR/SEMES. The Spanish Society of Anesthesia (SEDAR), Spanish Society of Internal Medicine (SEMI) and Spanish Society of Emergency Medicine (SEMES) have drawn up a position statement determining the competencies and training program for a diploma in ultrasound (lung, abdominal and vascular) in Intensive Care and Emergency Medicine. To obtain the SEDAR/SEMES Diploma in Ultrasound in Intensive Care and Emergency Medicine, clinicians must have completed the SEDAR, SEMI and SEMES Diploma in basic ultrasound and the Diploma in lung, abdominal, and vascular ultrasound.

Left Ventricle Outflow Tract Velocity-Time Index and Right Ventricle to Left Ventricle Ratio as Predictors for in Hospital Outcome in Intermediate-Risk Pulmonary Embolism

Accurate estimation of risk with both imaging and biochemical parameters in intermediate risk pulmonary embolism (PE) remains challenging. The aim of the study was to evaluate echocardiographic parameters that reflect right and left heart hemodynamic as predictors of adverse events in intermediate risk PE. This was a retrospective observational study on patients with computed tomography pulmonary angiography diagnosis of PE admitted at Cardiology department of the Clinical Emergency Hospital of Oradea, Romania between January 2018—December 2021. Echocardiographic parameters obtained at admission were studied as predictors of in hospital adverse events. The following adverse outcomes were registered: death, resuscitated cardiac arrest, hemodynamic deterioration and need of rescue thrombolysis. An adverse outcome was present in 50 patients (12.62%). PE related death was registered in 17 patients (4.3%), resuscitated cardiac arrest occurred in 6 patients (1.51%). Another 20 patients (5.05%) required escalation of therapy with thrombolysis and 7 (1.76%) patients developed haemodynamic instability. Echocardiographic independent predictors for in hospital adverse outcome were RV/LV ≥ 1 (HR = 3.599, 95% CI 1.378−9.400, p = 0.009) and VTI ≤ 15 mm (HR = 11.711, 95% CI 4.336−31.633, p < 0.001). The receiver operator curve renders an area under curve for LVOT VTI ≤ 15 mm of 0.792 (95% CI 0.719−0.864, p < 0.001) and for a RV/LV ≥ 1 of 0.746 (95% CI 0.671−0.821, p < 0.001). A combined criterion (LVOT VTI ≤ 15 and RV/LV ≥ 1) showed a positive predictive value of 75% and a negative predictive value of 95% regarding in hospital adverse outcomes. Low LVOT VTI and increased RV/LV are useful for identifying normotensive patients with PE at risk for short term adverse outcomes. Combining an LVOT VTI ≤ 15 cm with a RV/LV ≥ 1 can identify with increased accuracy PE patients with impending risk of clinical deterioration.

Ultrasound in postresuscitation care: a narrative review

The efficacy of ultrasound (US) in real-time differential diagnosis and guiding further treatment decisions has been well demonstrated in prearrest conditions and during resuscitation. Evidence is limited regarding the application of US in postresuscitation care. Most of the patients following resuscitation remain comatose, and the requirement for transportation to other examination rooms increases their risk of injury. US can be performed at the bedside with high accessibility and timeliness without radiation. This narrative review provides an overview of current evidence regarding the application of US in identifying the cause of cardiac arrest (CA), hemodynamic monitoring, and prognostication in postresuscitation care. For identifying the cause of CA, cardiac US is mainly used to detect regional wall motion abnormality. However, postarrest myocardial dysfunction would confound the sonographic findings that a combination of electrocardiograms and biomarkers besides the cardiac US could improve the positive predictive value of coronary artery disease. For hemodynamic monitoring, left ventricular outlet tract velocity time integral has the best performance in predicting fluid responsiveness in conjunction with the passive leg raising test. The RUSH protocol assists in determining the subtypes of shock with high sensitivity and specificity in hypovolemic, cardiogenic, or obstructive shock. Evidence regarding the application of US for prognostication is still limited, and further evaluation should be needed.

Ultrasound and Other Advanced Hemodynamic Monitoring Techniques in the Intensive Care Unit

The ideal device for hemodynamic monitoring of critically ill patients in the intensive care unit (ICU) or the operating room has not yet been developed. This would need to be affordable, consistent, have a very low margin of error (<30%), be minimally or noninvasive, and allow the clinician to make a reasonable therapeutic decision that consistently led to better outcomes. Such a device does not yet exist. This article will describe the distinct options we, as critical care physicians, currently possess for this Herculean endeavor.

Clinical Application of the Fluid Challenge Approach in Goal-Directed Fluid Therapy: What Can We Learn From Human Studies?

Resuscitative fluid therapy aims to increase stroke volume (SV) and cardiac output (CO) and restore/improve tissue oxygen delivery in patients with circulatory failure. In individualized goal-directed fluid therapy (GDFT), fluids are titrated based on the assessment of responsiveness status (i.e., the ability of an individual to increase SV and CO in response to volume expansion). Fluid administration may increase venous return, SV and CO, but these effects may not be predictable in the clinical setting. The fluid challenge (FC) approach, which consists on the intravenous administration of small aliquots of fluids, over a relatively short period of time, to test if a patient has a preload reserve (i.e., the relative position on the Frank-Starling curve), has been used to guide fluid administration in critically ill humans. In responders to volume expansion (defined as individuals where SV or CO increases ≥10–15% from pre FC values), FC administration is repeated until the individual no longer presents a preload reserve (i.e., until increases in SV or CO are <10–15% from values preceding each FC) or until other signs of shock are resolved (e.g., hypotension). Even with the most recent technological developments, reliable and practical measurement of the response variable (SV or CO changes induced by a FC) has posed a challenge in GDFT. Among the methods used to evaluate fluid responsiveness in the human medical field, measurement of aortic flow velocity time integral by point-of-care echocardiography has been implemented as a surrogate of SV changes induced by a FC and seems a promising non-invasive tool to guide FC administration in animals with signs of circulatory failure. This narrative review discusses the development of GDFT based on the FC approach and the response variables used to assess fluid responsiveness status in humans and animals, aiming to open new perspectives on the application of this concept to the veterinary field.

The effect of norepinephrine on common carotid artery blood flow in septic shock patients

This study was designed to evaluate the hemodynamic effect of norepinephrine (NE) on the peak systolic velocity (PSV), diameter, and blood flow of the common carotid artery (CCA) using the point-of-care ultrasound (POCUS) in patients with septic shock. The study involved patients above 18 years old with septic shock. Arterial monitoring, carotid ultrasonography, and transthoracic echocardiography were performed before NE administration (T₀). When the mean arterial pressure exceeded 65 mmHg after NE administration (T₁), the measurement was repeated. Twenty-four patients (median age 67 [interquartile range: 54–77] years; 42% female) with septic shock were examined in this study. Before (T₀) and after (T₁) NE administration, the PSV (mean, standard deviation [SD]) changed from 85.3 (21.1) cm/s to 83.5 (23.5) cm/s (p = 0.417); this change was not significant. However, the diameter and blood flow of the CCA increased significantly from 0.6 (0.09) cm and 0.75 (0.27) L/min to 0.66 (0.09) cm and 0.85 (0.27) L/min, respectively (p < 0.001). The diameter of the left ventricular outflow tract (LVOT) remained unchanged, but the velocity time integral of the LVOT increased significantly from 21.7 (4.39) cm to 23.6 (5.14) cm. There was no significant correlation between changes in blood flow of the CCA and changes in cardiac output (coefficient −0.365, p = 0.079). In conclusion, NE increased the diameter and blood flow of the CCA significantly, without changing the PSV in patients with septic shock.

Change in left ventricular velocity time integral during Trendelenburg maneuver predicts fluid responsiveness in cardiac surgical patients in the operating room

BACKGROUND

Fluid responsiveness is an important topic for clinicians. We investigated whether changes in left ventricular outflow tract (LVOT) velocity time integral (VTI) during a Trendelenburg position (TP) maneuver can predict fluid responsiveness as a non-invasive marker in coronary artery bypass graft (CABG) surgery patients in the operating room.

METHODS

This prospective, single-center observational study, performed in the operating room, enrolled 65 elective CABG patients. Hemodynamic data coupled with transesophageal echocardiography monitoring of the LVOT VTI and the peak velocity were collected at each step [baseline 1, TP, baseline 2 and fluid challenge (FC)]. Patients whose VTI increased ≥15% after FC (500 mL of Gelofusine infusion within 30 min) were considered responders.

RESULTS

Twenty-eight (43.1%) patients were responders to fluid administration. VTI changes during the TP maneuver predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.90 (95% CI, 0.79-0.96), with a sensitivity of 100%, and a specificity of 70% at a threshold of 10% (gray zone, 8-15%). The increase in VTI during the TP was correlated with the VTI changes induced by FC (r=0.61, P<0.0001). Changes in peak velocity and pulse pressure during the TP were poorly predictive of fluid responsiveness, with an AUC of 0.72 (95% CI: 0.60-0.82) and 0.66 (95% CI: 0.53-0.77), respectively.

CONCLUSIONS

An increase in VTI induced by the TP could predict fluid responsiveness in CABG patients in the operating room. However, changes in peak velocity and pulse pressure stimulated by the TP could not reliably predict fluid responsiveness.

Perioperative echocardiography-guided hemodynamic therapy in high-risk patients: a practical expert approach of hemodynamically focused echocardiography

The number of high-risk patients undergoing surgery is growing. To maintain adequate hemodynamic functioning as well as oxygen delivery to the vital organs (DO2) amongst this patient population, a rapid assessment of cardiac functioning is essential for the anesthesiologist. Pinpointing any underlying cardiovascular pathophysiology can be decisive to guide interventions in the intraoperative setting. Various techniques are available to monitor the hemodynamic status of the patient, however due to intrinsic limitations, many of these methods may not be able to directly identify the underlying cause of cardiovascular impairment. Hemodynamic focused echocardiography, as a rapid diagnostic method, offers an excellent opportunity to examine signs of filling impairment, cardiac preload, myocardial contractility and the function of the heart valves. We thus propose a 6-step-echocardiographic approach to assess high-risk patients in order to improve and maintain perioperative DO2. The summary of all echocardiographic based findings allows a differentiated assessment of the patient's cardiovascular function and can thus help guide a (patho)physiological-orientated and individualized hemodynamic therapy.

[Perioperative optimization using hemodynamically focused echocardiography in high-risk patients-A practice guide]

BACKGROUND

The number of high-risk patients undergoing surgery is steadily increasing. In order to maintain and, if necessary, optimize perioperative hemodynamics as well as the oxygen supply to the organs (DO₂) in this patient population, a timely assessment of cardiac function and the underlying pathophysiological causes of hemodynamic instability is essential for the anesthesiologist. A variety of hemodynamic monitoring procedures are available for this purpose; however, due to method-immanent limitations they are often not able to directly identify the underlying cause of cardiovascular impairment.

OBJECTIVE

To present a stepwise algorithm for a perioperative echocardiography-based hemodynamic optimization in noncardiac surgery high-risk patients. In this context, echocardiography on demand according to international guidelines can be performed under certain conditions (hemodynamic instability, nonresponse to hemodynamic treatment) as well as in the context of a planned intraoperative procedure, mostly as a transesophageal echocardiography.

METHODS AND RESULTS

Hemodynamically focused echocardiography as a rapidly available bedside method, enables the timely diagnosis and assessment of cardiac filling obstructions, volume status and volume response, right and left heart function, and the function of the heart valves.

CONCLUSION

Integrating all echocardiographic findings in a differentiated assessment of the patient's cardiovascular function enables a (patho)physiologically oriented and individualized hemodynamic treatment.

Use of aortic flow indexes derived from transthoracic echocardiography to evaluate response to a fluid challenge in anesthetized dogs

OBJECTIVE

To evaluate the ability of transthoracic echocardiographic aortic flow measurements to discriminate response to a fluid challenge (FC) in healthy anesthetized dogs.

STUDY DESIGN

Prospective experimental study.

ANIMALS

A total of 48 isoflurane-anesthetized dogs (14.2-35.0 kg) undergoing elective surgery.

METHODS

Fluid responsiveness was evaluated before surgery by FC (lactated Ringer's 10 mL kg^-1 intravenously over 5 minutes). Percentage increases in transpulmonary thermodilution stroke volume (ΔSV_TPTD) >15% from values recorded before FC defined responders to volume expansion. A group of 24 animals were assigned as nonresponders (ΔSV_TPTD ≤15%). When ΔSV_TPTD was >15% after the first FC, additional FC were administered until ΔSV_TPTD was ≤15%. Final fluid responsiveness status was based on the response to the last FC. Percentage increases after FC in aortic flow indexes [velocity time integral (ΔVTI_FC) and maximum acceleration (ΔVmax_FC)] and in mean arterial pressure (ΔMAP_FC) were compared with ΔSV_TPTD.

RESULTS

After one FC, 24 animals were responders. For nonresponders, ΔSV_TPTD was ≤15% after one, two and three FCs in eight/24, 15/24 and one/24 animals, respectively. The FC that defined responsiveness increased ΔSV_TPTD by 29 (18-53)% in responders and by 8 (-3 to 15)% in nonresponders [mean (range)]. The area under the receiver operating characteristics curve (AUROC) of ΔVTI_FC (0.901) was larger than the AUROCs of ΔVmax_FC (0.774, p = 0.041) and ΔMAP_FC (0.519, p < 0.0001). ΔMAP_FC did not predict responsiveness (p = 0.826). Best cut-off thresholds for discriminating responders, with respective zones of diagnostic uncertainty (gray zones) were >14.7 (10.8-17.6)% for ΔVTI_FC and >8.6 (-0.3 to 14.7)% for ΔVmax_FC. Animals within the gray zone were 17% (ΔVTI_FC) and 50% (ΔVmax_FC).

CONCLUSIONS AND CLINICAL RELEVANCE

Changes in VTI induced by FC can determine responsiveness with reasonable accuracy in dogs and could play an important role in goal-directed fluid therapy.

The Effects of Positional Change on Hemodynamic Parameters in Spinal Immobilization

INTRODUCTION

The use of a long backboard and cervical collar are commonly recommended by international guidelines for spinal immobilization, but both devices may cause several side effects. In a recent study, it was reported that spinal immobilization at 20° eliminated the decrease in pulmonary function secondary to spinal immobilization performed at 0°. Spinal immobilization at 20° is a new recommendation, but other potential effects need to be explored before it can be implemented in clinical use.

STUDY OBJECTIVE

Hemodynamic observation is important in the management of trauma patients. The aim of this study was to investigate the effect of spinal immobilization at a 20° position instead of 0° on hemodynamic parameters.

METHODS

This study included 53 healthy volunteers who underwent spinal immobilization in the supine position (00) and in an elevated position (200). Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), left ventricular outflow tract velocity time integral (LVOT-VTI), left ventricular stroke volume (LVSV), cardiac output (CO), inferior vena cava diameter inspiration (IVC diameter insp), IVC diameter expiration (IVC diameter exp), and inferior vena cava collapsibility index (IVC-CI) were measured at the 0th and 30th minutes of spinal immobilization in both positions. The data were compared for demonstrating the efficiency of both positions in spinal immobilization.

RESULTS

A statistically significant difference was found in the parameters of the IVC diameter (exp), IVC diameter (insp), LVOT-VTI, LVSV, and CO through the measurements starting in the 0th minute of the transition from 0° to 20° (P <.001). Delta values (∆) of hemodynamic parameters (∆IVC diameter [exp], ∆IVC diameter [insp], ∆LVOT-VTI, ∆SV, ∆CO, ∆IVC-CI, ∆MAP, ∆SAP, ∆DAP, and ∆HR) were similar in spinal immobilization at 0° and 20°.

CONCLUSION

The findings obtained from this study illustrate that spinal immobilization at 20° does not cause clinically significant hemodynamic changes in healthy subjects compared to spinal immobilization at 0°.

Identifying cardiogenic shock in the emergency department

INTRODUCTION

Cardiogenic shock is difficult to diagnose due to diverse presentations, overlap with other shock states (i.e. sepsis), poorly understood pathophysiology, complex and multifactorial causes, and varied hemodynamic parameters. Despite advances in interventions, mortality in patients with cardiogenic shock remains high. Emergency clinicians must be ready to recognize and start appropriate therapy for cardiogenic shock early.

OBJECTIVE

This review will discuss the clinical evaluation and diagnosis of cardiogenic shock in the emergency department with a focus on the emergency clinician.

DISCUSSION

The most common cause of cardiogenic shock is a myocardial infarction, though many causes exist. It is classically diagnosed by invasive hemodynamic measures, but the diagnosis can be made in the emergency department by clinical evaluation, diagnostic studies, and ultrasound. Early recognition and stabilization improve morbidity and mortality. This review will focus on identification of cardiogenic shock through clinical examination, laboratory studies, and point-of-care ultrasound.

CONCLUSIONS

The emergency clinician should use the clinical examination, laboratory studies, electrocardiogram, and point-of-care ultrasound to aid in the identification of cardiogenic shock. Cardiogenic shock has the potential for significant morbidity and mortality if not recognized early.

Right ventricular stroke distance predicts death and clinical deterioration in patients with pulmonary embolism

PURPOSE

The right ventricular outflow tract (RVOT) velocity time integral (VTI), an echocardiographic measure of stroke distance, correlates with cardiac index. We sought to determine the prognostic significance of low RVOT VTI on clinical outcomes among patients with acute pulmonary embolism (PE).

MATERIALS AND METHODS

We conducted a retrospective review of echocardiograms on Pulmonary Embolism Response Team (PERT) activations at our institution. The main outcome was a composite of death, cardiac arrest, or hemodynamic deterioration.

RESULTS

Of 188 patients, 30 met the combined outcome (16%) and had significantly lower RVOT VTI measurements (9.0 cm v 13.4 cm, p < 0.0001). The AUC for RVOT VTI at a cutoff of 10 cm was 0.78 (95% CI 0.67-0.90) with a sensitivity, specificity, negative predictive value, and positive predictive value of 0.72, 0.81, 0.94, and 0.42, respectively. Fifty-two patients of the cohort were classified as intermediate-high-risk PE and 21% of those met the combined outcome. RVOT VTI was lower among outcome positive patients (7.3 cm v 10.7 cm, p = 0.02).

CONCLUSIONS

Low RVOT VTI is associated with poor clinical outcomes among patients with acute PE.

Rationale for using the velocity-time integral and the minute distance for assessing the stroke volume and cardiac output in point-of-care settings

Background

Stroke volume (SV) and cardiac output (CO) are basic hemodynamic parameters which aid in targeting organ perfusion and oxygen delivery in critically ill patients with hemodynamic instability. While there are several methods for obtaining this data, the use of transthoracic echocardiography (TTE) is gaining acceptance among intensivists and emergency physicians. With TTE, there are several points that practitioners should consider to make estimations of the SV/CO as simplest as possible and avoid confounders.

Main body

With TTE, the SV is usually obtained as the product of the left ventricular outflow tract (LVOT) cross-sectional area (CSA) by the LVOT velocity–time integral (LVOT VTI); the CO results as the product of the SV and the heart rate (HR). However, there are important drawbacks, especially when obtaining the LVOT CSA and thus the impaction in the calculated SV and CO. Given that the LVOT CSA is constant, any change in the SV and CO is highly dependent on variations in the LVOT VTI; the HR contributes to CO as well. Therefore, the LVOT VTI aids in monitoring the SV without the need to calculate the LVOT CSA; the minute distance (i.e., SV × HR) aids in monitoring the CO. This approach is useful for ongoing assessment of the CO status and the patient’s response to interventions, such as fluid challenges or inotropic stimulation. When the LVOT VTI is not accurate or cannot be obtained, the mitral valve or right ventricular outflow tract VTI can also be used in the same fashion as LVOT VTI. Besides its pivotal role in hemodynamic monitoring, the LVOT VTI has been shown to predict outcomes in selected populations, such as in patients with acute decompensated HF and pulmonary embolism, where a low LVOT VTI is associated with a worse prognosis.

Conclusion

The VTI and minute distance are simple, feasible and reproducible measurements to serially track the SV and CO and thus their high value in the hemodynamic monitoring of critically ill patients in point-of-care settings. In addition, the LVOT VTI is able to predict outcomes in selected populations.

Evaluation of the caudal vena cava diameter to abdominal aortic diameter ratio and the caudal vena cava respiratory collapsibility for predicting fluid responsiveness in a heterogeneous population of hospitalized conscious dogs

Fluid responsiveness, defined as the response of stroke volume to fluid loading, is a tool to individualize fluid administration in order to avoid the deleterious effects of hypovolemia or hypervolemia in hospitalized patients. To evaluate the accuracy of two ultrasound indices, the caudal vena cava to abdominal aorta ratio (CVC/Ao) and the respiratory collapsibility of the caudal vena cava (cCVC), as independent predictors of fluid responsiveness in a heterogeneous population of spontaneously breathing, conscious, hospitalized dogs. A prospective, multicenter, observational, cross-sectional study was designed in twenty-five dogs. The accuracy of CVC/Ao and cCVC in predicting fluid responsiveness was evaluated by the area under the receiver operating characteristic curve (AUROC) in a group of hospitalized dogs after receiving a mini-fluid bolus of 4 ml/kg of Hartmann's solution. Dogs with an increased aortic velocity time integral >15% were classified as fluid responders. Twenty-two dogs were finally included. Ten were classified as responders and 12 as non-responders. The AUROC curves were 0.88 for the CVC/Ao ratio (95% confidence interval, CI, 0.67-0.98; P=0.0001) and 0.54 for cCVC (95% CI 0.32-0.75; P=0.75). The CVC/Ao threshold optimized for best sensitivity (SE) and specificity (SP) values was 0.83 (SE 100%; SP 75%). In spontaneously breathing hospitalized dogs, the CVC/Ao measurement predicted stroke volume increase after a fluid bolus, while the respiratory variations in the cCVC did not discriminate between fluid responders and non-responders.

Accuracy of Passive Leg Raising Test in Prediction of Fluid Responsiveness in Children

Aim

To assess the accuracy of the passive leg raising (PLR) test to anticipate fluid responsiveness in critically ill children under age of 5 years.

Materials and methods

A prospective observational study was conducted, in a university hospital pediatric intensive care unit from June 1, 2017, to January 30, 2018. Hemodynamic parameters including stroke volume using bedside transthoracic echocardiography were assessed at baseline I (45° semi-recumbent position), after PLR, at baseline II, and following fluid challenge. Changes in the stroke volume (delta SV) and in the cardiac index (CI) were recorded after PLR and fluid challenge.

Findings

Delta SV of 10% after PLR was an excellent discriminator of the fluid responsiveness with an area under ROC (AUC) of 0.81 (95% CI 0.68-0.9) with a sensitivity of 65.38% and a specificity of 100%. The change in CI of 8.7% after PLR was a significant discriminator of fluid responsiveness with an AUC of 0.7 (95% CI 0.56-0.81) with 57.78% sensitivity and 91.67% specificity.

Conclusion

Passive leg raising can identify nonresponders among seriously ill children under the age of 5 years but it cannot identify all responders with certainty.

Clinical significance

Passive leg raising is reliable test in under 5 year-old-children if performed appropriately using bedside echocardiography for the measurement of its transient effect.

How to cite this article

El-Nawawy AA, Farghaly PM, Hassouna HM, Accuracy of Passive Leg Raising Test in Prediction of Fluid Responsiveness in Children. Int J Clin Pediatr Dent 2020;24(5):344-349.

Low left ventricular outflow tract velocity time integral is associated with poor outcomes in acute pulmonary embolism

The left ventricular outflow tract (LVOT) velocity time integral (VTI) is an easily measured echocardiographic stroke volume index analog. Low values predict adverse outcomes in left ventricular failure. We postulate the left ventricular VTI may be a signal of right ventricular dysfunction in acute pulmonary embolism, and therefore a predictor of poor outcomes. We retrospectively reviewed echocardiograms on all Pulmonary Embolism Response Team activations at our institution at the time of pulmonary embolism diagnosis. Low LVOT VTI was defined as ⩽ 15 cm. We examined two composite outcomes: (1) in-hospital death or cardiac arrest; and (2) shock or need for primary reperfusion therapies. Sixty-one of 188 patients (32%) had a LVOT VTI of ⩽ 15 cm. Low VTI was associated with in-hospital death or cardiac arrest (odds ratio (OR) 6, 95% CI 2, 17.9; p = 0.0014) and shock or need for reperfusion (OR 23.3, 95% CI 6.6, 82.1; p < 0.0001). In a multivariable model, LVOT VTI ⩽ 15 remained significant for death or cardiac arrest (OR 3.48, 95% CI 1.02, 11.9; p = 0.047) and for shock or need for reperfusion (OR 8.12, 95% CI 1.62, 40.66; p = 0.011). Among intermediate-high-risk patients, low VTI was the only variable associated with the composite outcome of death, cardiac arrest, shock, or need for reperfusion (OR 14, 95% CI 1.7, 118.4; p = 0.015). LVOT VTI is associated with adverse short-term outcomes in acute pulmonary embolism. The VTI may help risk stratify patients with intermediate-high-risk pulmonary embolism.

An Analysis Using Modified Rapid Ultrasound for Shock and Hypotension for Patients with Endogenous Cardiac Arrest

AIMS

We prospectively investigated whether or not a rapid ultrasound for shock and hypotension (RUSH) examination is useful for managing patients with endogenous cardiac arrest (CA).

SETTINGS AND DESIGN

A prospective medical chart review in a single hospital.

MATERIALS AND METHODS

From March 2016 to December 2017, we performed a modified RUSH for all patients with out-of-hospital endogenous CA. We investigated the frequency of positive findings on modified RUSH and what kind of diseases could most easily be pinpointed as the cause of CA by the modified RUSH.

RESULTS

During the investigation period, 194 participants were enrolled in the present study. They were primarily male, with an average age of 68.8-year-old, and 178/194 (91.7%) died as outpatients. The most frequent cause of CA was cardiogenic, followed by aortic disease, respiratory failure, and stroke except for unknown. There were 14/26 (54%) aortic disease patients who showed positive RUSH findings. Among cases of the aortic disease, only aortic dissections had positive findings. Aside from aortic disease, there were no cases of positive findings of the modified RUSH among the remaining diseases, and all patients with positive findings died. Only pulseless electrical activity (PEA) was a statistically significant factor for positive findings of the modified RUSH in cases of the aortic disease.

CONCLUSIONS

The present study revealed that, among patients with out-of-hospital endogenous CA, modified RUSH is useful for diagnosing ascending aortic dissection for the detection of hemothorax and/or cardiac tamponade, especially with PEA.

Vaginal Bleeding in Late Pregnancy

Bleeding in late-term pregnancy can present as an innocuous start to parturition or a catastrophic maternal-fetal hemorrhage masked by the physiologic adaptations of pregnancy. The emergency management of late-term bleeding can be challenging, especially when providing stabilizing care in a limited-resource environment. Early recognition of life-threatening vaginal bleeding, potential causes, and emergency management of maternal-fetal distress is reviewed. Maternal resuscitation with balanced versus targeted blood products replacement is presented for low-resource versus high-resource environments. Emergency department readiness for such a patient, in combination with appropriate consultation or transfer, is essential to the effective management of late-term vaginal bleeding.

The utility of limited trans-thoracic echocardiography in the stratification of pulse pressure variation: A feasibility study in major open abdominal surgery

Background and Aim:

Limitation in use of pulse pressure variation (PPV) in predicting fluid responsiveness (FR) in hypotensive patients is encountered when values are in the “gray zone” (8–13%). Dynamic arterial elastance (E_adyn= PPV/SVV) can be used in such situations to predict arterial pressure response to volume expansion (VE). In our study, we used respiratory variation of ascending aorta velocity time integral (AoVTI) calculated from suprasternal window as a surrogate of stroke volume variation (SVV). Fluids/vasopressors were administered to hypotensive patients intraoperatively based on value of E_adyn. Aim was to assess feasibility and utility of suprasternal echocardiography in the above-mentioned subset of patients.

Materials and Methods:

Hemodynamic data were monitored and respiratory variation in AoVTI was recorded using suprasternal echocardiography at all time points when patients developed hypotension (systolic blood pressure <90 mm Hg/<20% of baseline for 5 min) and at randomly selected time intervals when hemodynamic stability was maintained. VE with 250 ml of Ringer lactate (RL) was done in hypotensive patients with PPV value of 8–13% and E_adyn>0.9. Increase of >15% in AoVTI after VE defined “fluid responsiveness.”

Results:

Twenty-eight patients were enrolled, but three were excluded in view of left ventricular systolic dysfunction detected during preinduction echocardiography. Hemodynamic and echocardiographic data were recorded at 538 observation points in 25 adults. Hypotension occurred in 247 data sets, and in 168 data sets, value of PPV was 8–13%. VE was carried out in only those 131 data sets in which the value of E_adyn was >0.9. Area under the curve (AUC) for VE as an intervention in the indeterminate (PPV 8–13%) group was 0.574 (0.49–0.68, 95% CI, P < 0.049), and in the observation set with PPV >13, the AUC value was 0.7 (0.59–0.98, 95% CI, P < 0.01).

Conclusions:

Echocardiography using the suprasternal window in the operating room during abdominal surgery is feasible, but the utility of E_adyn in stratification of patients with PPV 8–13% is inconclusive.

Reference intervals and percentile curve for left ventricular outflow tract (LVOT), velocity time integral (VTI), and LVOT-VTI-derived hemodynamic parameters in healthy children and adolescents: Analysis of echocardiographic methods association and agreement

BACKGROUND

Echocardiographic reference intervals (RIs) for left ventricular outflow tract (LVOT) and velocity time integral (VTI) are scarce in pediatrics.

AIMS

(a) to generate RIs and percentiles for LVOT, VTI, and hemodynamic variables in healthy children and adolescents from Argentina; (b) to analyze the equivalence between stroke volume (SV), cardiac output (CO), and cardiac index (CI) obtained from two-dimensional echocardiography (2D) and LVOT-VTI analysis with pulsed wave Doppler (PWD); and (c) to analyze the association between subjects' characteristics and VTI and LVOT-VTI-derived parameters.

METHODS

Two-dimensional and PWD studies were done in 385 subjects (5-24 years). Mean and standard deviation age-related and body surface area (BSA)-related equations were obtained for VTI and LVOT-VTI-derived parameters (parametric regression methods based on fractional polynomials). BSA- and age-specific percentiles were determined.

RESULTS

Pulsed wave Doppler- and 2D-derived parameters were positively correlated. However, PWD values were always lower than those from 2D. Specific RIs for PWD and 2D data were necessary. Covariance analysis showed that sex-specific RIs were required for LVOT, but not for VTI, VTI-derived CO and CI. Age-related RIs were obtained for LVOT, LVOT-VTI, and VTI-derived CO and CI. BSA-related RIs for VTI-derived CO and CI were obtained.

CONCLUSIONS

Stroke volume, CO, and CI data from 2D and PWD are not equivalent. An accurate analysis of LVOT-VTI-derived parameters requires considering age and BSA. In this study, age- and BSA-related RIs and percentiles for LVOT, VTI, and hemodynamic parameters in healthy children and adolescents were determined, discriminating data according to the methodological approach (2D or PWD).