IJV collapsibility index vs IVC collapsibility index by point of care ultrasound for estimation of CVP: a comparative study with direct estimation of CVP

Correlation of Internal Jugular Vein Collapsibility With Central Venous Pressure in Patients With Liver Cirrhosis

We aimed to compare internal jugular vein and inferior vena cava ultrasonography as predictors of central venous pressure in cirrhotic patients. We performed ultrasound assessments of the internal jugular vein (IJV) and the inferior vena cava and then invasively measured central venous pressure (CVP). We then compared their correlation with CVP and performed area under the receiver operating characteristic curves to determine which had best sensitivity and specificity. IJV cross-sectional area collapsibility index at 30° correlated better with CVP ( r = -0.56, P < 0.001), and an IJV AP-CI at 30° ≤ 24.8% was better at predicting a CVP ≥8 mm Hg, with 100% sensitivity and 97.1% specificity. Thus, IJV point-of-care ultrasound might be superior than inferior vena cava point-of-care ultrasound as a predictor of CVP in cirrhotic patients.

Role of Internal Jugular Vein Collapsibility Index in Predicting Post-spinal Hypotension in Pregnant Women Undergoing Cesarean Section: A Prospective Observational Study

Introduction Post-spinal hypotension (PSH) frequently occurs in women undergoing cesarean section. In recent studies, Ultrasound-guided measurements of the internal jugular vein (IJV) have been reported to predict fluid responsiveness. We planned to evaluate the correlation between the internal jugular vein collapsibility index (IJVCI) and PSH in cesarean section patients. Methods Ninety-one parturients who underwent elective lower segment cesarean section with a singleton pregnancy were recruited. Preoperatively, patients were placed in a supine position with a 15-degree left lateral tilt. Maximum (at the end of expiration) and minimum (at the end of inspiration) IJV diameters (mm) and IJVCI were assessed using M-mode imaging during spontaneous and deep breathing. Spinal anaesthesia was performed at the L3-4 or L4-5 level. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, respiratory rate, and SpO2 were recorded from baseline till the delivery of the baby. Results Among 91 patients, 40 (45.5%) patients had at least one episode of hypotension. Demographic variables and baseline vitals were comparable between the hypotensive and normotensive groups (p>0.05). In spontaneous and deep breathing, IJV diameter at the end-expiration (IJVdmax), end-inspiration (IJVdmin), and IJVCI amongst both hypotensive and non-hypotensive pregnant women were statistically similar. Receiver Operating Characteristic (ROC) curve analysis showed that during spontaneous breathing, using a cut-off point of 29.5%, IJVCI had a sensitivity and specificity of 70% and 23%, respectively, for predicting PSH; whereas during deep breathing, IJVCI had a sensitivity and specificity of 77% and 27%, respectively, for predicting the same using a cut-off value of 37.5%. Conclusion We conclude that internal jugular vein parameters such as maximum diameter, minimum diameter, and IJVCI during spontaneous and deep breathing cannot be used as reliable predictors of post-spinal hypotension in pregnant patients undergoing elective cesarean section.

Point-of-care ultrasonography in nephrology comes of age

The physical exam is changing. Many have argued that the physical exam of the 21st century should include point-of-care ultrasound (POCUS). POCUS is being taught in medical schools and has been endorsed by the major professional societies of internal medicine. In this review we describe the trend toward using POCUS in medicine and describe where the practicing nephrologist fits in. We discuss what a nephrologist's POCUS exam should entail and we give special attention to what nephrologists can gain from learning POCUS. We suggest a 'nephro-centric' approach that includes not only ultrasound of the kidney and bladder, but of the heart, lungs and vascular access. We conclude by reviewing some of the sparse data available to guide training initiatives and give suggested next steps for advancing POCUS in nephrology.

Internal jugular vein ultrasound for the diagnosis of hypovolemia and hypervolemia in acutely ill adults: a systematic review and meta-analysis

Accurate volume status assessments allow physicians to rapidly implement therapeutic measures in acutely unwell patients. However, existing bedside diagnostic tools are often unreliable for assessing intravascular volume. We searched PUBMED, EMBASE, CENTRAL, and Web of Science for English language articles without date restrictions on January 20, 2022. Studies reporting the diagnostic accuracy of IJV-US for hypovolemia and/or hypervolemia in an acute care setting were screened for inclusion. We included studies using any method of IJV-US assessment as the index test, compared against any reference standard. We fitted hierarchical summary receiver operating characteristic (HSROC) models for meta-analysis of diagnostic test accuracy, separately for hypovolemia and hypervolemia. Two reviewers independently extracted data and assessed risk of bias using QUADAS-2. We assessed certainty of evidence using the GRADE approach. A total of 26 studies were included, of which 19 studies (956 patients) examined IJV-US for hypovolemia and 13 studies (672 patients) examined IJV-US for hypervolemia. For the diagnosis of hypovolemia, IJV-US had a pooled sensitivity of 0.82 (95% CI 0.76 to 0.87; moderate-certainty evidence) and specificity of 0.82 (95% CI 0.73 to 0.88; moderate-certainty evidence). Measurement of IJV collapsibility indices had higher diagnostic accuracy (sensitivity 0.85, 95% CI 0.80 to 0.89; specificity 0.78, 95% CI 0.64 to 0.88) than static IJV indices (sensitivity 0.73, 95% CI 0.60 to 0.82; specificity 0.70, 95% CI 0.48 to 0.86). For the diagnosis of hypervolemia, IJV-US had a pooled sensitivity of 0.84 (95% CI 0.70 to 0.92; moderate-certainty evidence) and specificity of 0.70 (95% CI 0.55 to 0.82; very low-certainty evidence). IJV-US has moderate sensitivity and specificity for the diagnosis of hypervolemia and hypovolemia. Randomized controlled trials are needed to determine the role of IJV-US for guiding therapeutic interventions aimed at optimizing volume status.

Bedside ultrasound to assess acute central venous pressure change during treatment of decompensated heart failure

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Volume status assessment by physical exam in heart failure patients is often inaccurate.

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Right heart catheterization (RHC) carries safety, pragmatic and financial burdens.

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A non-invasive, safe, and reliable alternative for accurate assessment of volume status is needed for optimal management of heart failure.

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Serial portable ultrasonic assessment of internal jugular vein compliance can act as a surrogate for RHC to determine volume status.

Background

Accurate volume status assessment is crucial for the treatment of acute decompensated heart failure (ADHF). Volume status assessment by physical exam is often inaccurate, necessitating invasive measurement with right heart catheterization (RHC), which carries safety, pragmatic (scheduling, holding anticoagulants, etc.), and financial burdens. Therefore, a reliable, non-invasive, cost-effective alternative is desired. Previously, we developed an ultrasound (US) based technique to measure internal jugular vein (IJV) compliance during RHC which was used for single time point central venous pressure (CVP) predictions. We now aim to apply this technique to track acute changes in CVP during diuresis for ADHF in patients with an in-dwelling pulmonary artery catheter (PAC).

Methods

We used an observational, prospective study design and recruited 15 patients from the cardiac critical unit (CCU) being treated for ADHF (systolic or diastolic) with intravenous (IV) diuretics with/without inotropic agents who underwent Swan- Ganz catheter/PAC insertion for continuous CVP monitoring. 13 of 15 patients received milrinone infusions. US images of the IJV were obtained at end-expiration and during the strain phase of Valsalva at multiple 2–3 hours intervals. Change in IJV cross-sectional area (CSA) (ImageJ) was used as a measure of IJV compliance. Patients unable to perform the Valsalva maneuver were excluded.

Results

Calculated percentage change (%Δ) in CSA of IJV was plotted against CVP. An inverse relationship was observed between CVP and %Δ in CSA of IJV. The data was fit with a polynomial regression curve (R² = 0.36, root mean square error = 3.19). Fivefold cross-validation showed a stable model for predicting CVP based on CSA (R² = 0.31, root mean square error = 3.18)

Conclusion

Serial portable US assessment of IJV compliance can act as a surrogate measure of CVP and, therefore, can provide reliable information on acute hemodynamic changes in ADHF.

Pre-operative Ultrasonographic Evaluation of the Internal Jugular Vein Collapsibility Index and Inferior Vena Cava Collapsibility Index to Predict Post Spinal Hypotension in Pregnant Women Undergoing Caesarean Section

Background: Post spinal anesthesia hypotension (PSAH) is frequently encountered in anesthetic practice, especially during cesarean section. Ultrasound is a safe and easy technique for hemodynamic monitoring. Objectives: This study was conducted to assess the efficacy of pre-operative inferior vena cava collapsibility index (IVCCI) and internal jugular vein collapsibility index (IJVCI) in predicting PSAH. Methods: This cross-sectional blinded study included 55 pregnant females prepared for elective cesarean section. They were divided into two groups based on the incidence of PSAH: (1) cases with PSAH (26 cases); and (2) cases without PSAH (29 cases). All the cases underwent ultrasound-guided measurement of IVCCI and IJVCI. The efficacy of these parameters was assessed in predicting PSAH. Results: Cases in both groups expressed non-significant differences regarding demographic data. However, IVCCI had mean values of 38.27 and 23.97%, while IJVCCI had mean values of 46.50 and 33.41%, respectively, in cases with and without PSAH. For IVCCI, using a cut-off point of 33% had sensitivity and specificity (84.6 and 93.1%, respectively) for predicting PSAH, with a diagnostic accuracy of 89.1%. IJVCI had sensitivity and specificity of 84.6 and 82.8%, respectively, for predicting the same complication using a cut-off value of 38.5%. Conclusion: IVCCI and IJVCI are efficacious and reliable tools in predicting PSAH in pregnant ladies undergoing cesarean section, with a slight superiority for IVCCI regarding specificity and accuracy.

Point-of-Care Ultrasound for the Trauma Anesthesiologist

Purpose of Review

With advances in technology and availability of handheld ultrasound probes, studies are focusing on the perioperative care of patients, but a limited number specifically on trauma patients. This review highlights recent findings from studies using point of care ultrasound (POCUS) to improve the care of trauma patients.

Recent Findings

Major findings include the use of POCUS to assess volume status of trauma patients upon arrival to measure the major vasculature. Additionally, several studies have advanced the use of POCUS to identify pneumothorax in trauma patients. Finally, the ASA POCUS certification and ASRA expert guidelines are examples of international organizations establishing guidelines for utilization and training of anesthesiologists in the field of POCUS, which will be discussed.

Summary

Despite the COVID-19 pandemic, and considerable resources being diverted to fight this global healthcare crisis, advances are being made in utilization of POCUS to aid the care of trauma patients.

Ultrasound-guided estimation of internal jugular vein collapsibility index in patients with shock in emergency department

OBJECTIVE:

To correlate ultrasound-guided estimation of Internal Jugular Vein Collapsibility Index (IJV-CI) with inferior vena cava CI (IVC-CI) and invasively monitored central venous pressure (CVP) in patients with shock in the emergency medicine department.

METHODS:

A prospective observational study was done in the emergency department (ED). The study was conducted over 15 months (November 2019 to April 2021). It included patients more than 18 years presenting to the ED in shock. The IJV and IVC diameter and cross-sectional area were measured using ultrasound. The corresponding collapsibility indexes were then calculated and correlated with the invasively monitored CVP of the patient. Data were then analyzed using the Statistical Package for the Social Science (SPSS): Version 23 for windows. Pearson's correlation was used between CVP and collapsibility indexes.

RESULTS:

The mean (±standard deviation) age of the patients was 49.01 (±15.6). There was a 47 (64%) male predominance which outnumbered females 26 (36%). The correlation coefficient was statistically significant between CVP and the collapsibility indices for various IJV and IVC parameters. The highest correlation (r = −0.541, P = 0.005) was seen between IVC-CI (CI 5) and CVP. This was followed by a correlation seen at a 30° position for IJV CI (cross-sectional area) with CVP (r = −0.453, P = 0.001). Similarly, the correlation between IJV CI (AP diameter) and CVP, followed (r = −0.412, P = 0.008) was statistically significant.

CONCLUSION:

Both IJV and IVC collapsibility indices correlated significantly with invasively measured CVP. Hence, they present as an effective tool in fluid resuscitation in patients with shock in ED.

Ultrasonography in Acute Kidney Injury

Advances in the use of ultrasonography can enhance our ability to better characterize acute kidney injury (AKI). AKI is a clinical syndrome characterized by a rapid decrease in kidney excretory function with the accumulation of products of nitrogen metabolism and other clinically unmeasured waste products, and may proceed to include clinical manifestations including decreased urine output, development of metabolic acidosis, and electrolyte abnormalities [1]. The Kidney Disease Improving Global Outcomes (KDIGO) criteria defines AKI (Table 1). Staging severity of AKI guides the physician in respect to medical management and prognosis. The overall incidence of AKI is around 20% of patients hospitalized worldwide, and around 50% in intensive care unit (ICU) patients [2, 3]. AKI has been found to have increasing morbidity and mortality, no matter the cause of admission, as well as an in-hospital mortality of close to 50% [4]. In a large study of 8 ICUs over 8 years, Kellum et al. found that AKI was associated with increasing mortality rate with worsening AKI stage. A decrease in urine output alone, without an increase in serum creatinine, was associated with decreased 1-year survival [5]. Recurrent AKI has also been associated with increased mortality, further demonstrating the importance of detecting, monitoring, and diagnosing AKI [6].

Measuring the ratio of femoral vein diameter to femoral artery diameter by ultrasound to estimate volume status

Background

Currently, the accepted effective method for assessing blood volume status, such as measuring central venous pressure (CVP) and mean pulmonary artery pressure (mPAP), is invasive. The purpose of this study was to explore the feasibility and validity of the ratio of the femoral vein diameter (FVD) to the femoral artery diameter (FAD) for predicting CVP and mPAP and to calculate the cut-off value for the FVD/FAD ratio to help judge a patient’s fluid volume status.

Methods

In this study, 130 patients were divided into two groups: in group A, the FVD, FAD, and CVP were measured, and in group B, the FVD, FAD, and mPAP were measured. We measured the FVD and FAD by ultrasound. We monitored CVP by a central venous catheter and mPAP by a Swan-Ganz floating catheter. Pearson correlation coefficients were calculated. The best cut-off value for the FVD/FAD ratio for predicting CVP and mPAP was obtained according to the receiver operating characteristic (ROC) curve.

Results

The FVD/FAD ratio was strongly correlated with CVP (R = 0.87, P < 0.0000) and mPAP (R = 0.73, P < 0.0000). According to the ROC curve, an FVD/FAD ratio ≥ 1.495 had the best test characteristics to predict a CVP ≥ 12 cmH₂O, and an FVD/FAD ratio ≤ 1.467 had the best test characteristics to predict a CVP ≤ 10 cmH₂O. An FVD/FAD ratio ≥ 2.03 had the best test characteristics to predict an mPAP ≥ 25 mmHg. According to the simple linear regression curve of the FVD/FAD ratio and CVP, when the predicted CVP ≤ 5 cmH₂O, the FVD/FAD ratio was ≤ 0.854.

Conclusion

In this study, the measurement of the FVD/FAD ratio obtained via ultrasound was strongly correlated with CVP and mPAP, providing a non-invasive method for quickly and reliably assessing blood volume status and providing good clinical support.