Correlation of IVC Diameter and Collapsibility Index With Central Venous Pressure in the Assessment of Intravascular Volume in Critically Ill Patients

Sonographic findings using the SAFE-A protocol in pre- and post-hemodialysis patients

BACKGROUND

Accurate assessment of relative intravascular volume is one of the cornerstones for the proper management of hospitalized patients requiring hemodialysis. Currently, the use of dynamic parameters such as bedside ultrasonography is recommended to support the assessment of the intravascular volume profile. This study aimed to prospectively evaluate findings of sonographic assessment of intravascular volume estimate (SAFE-A) protocol among hemodialysis inpatients with end-stage renal disease, before and after the hemodialysis sessions, and correlate these findings with the net ultrafiltrate (UFNET).

RESULTS

A positive correlation was found between the negative variation of 1 point in the score of the SAFE-A protocol with the withdrawal of 426.73 mL of net ultrafiltrate.

CONCLUSIONS

There was a strong correlation between the score of the SAFE-A protocol and the net ultrafiltrate. Therefore, this study concludes that the application of the SAFE-A protocol in dialysis patients demonstrates a correlation between the suggested score and volume status, consistent with findings from the original study conducted in a distinct population.

Splanchnic Nerve Modulation Effects on Surrogate Measures of Venous Capacitance

Background Splanchnic nerve modulation (SNM) is an emerging procedure to reduce cardiac filling pressures in heart failure. Although the main contributor to reduction in cardiac preload is thought to be increased venous capacitance in the splanchnic circulation, supporting evidence is limited. We examined changes in venous capacitance surrogates pre- and post-SNM. Methods and Results This is a prespecified analysis of a prospective, open-label, single-arm interventional study evaluating the effects of percutaneous SNM with ropivacaine in chronic heart failure with elevated filling pressures at rest and with exercise. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment pre- and post-SNM. Blood pressure changes with modified Valsalva maneuver and hemoconcentration, pre- and post-SNM were compared using a repeated measures model. Inferior vena cava diameter and collapsibility (>50% decrease in size with inspiration), and presence of bendopnea pre- and post-SNM were also compared. Fifteen patients undergoing SNM (age 58 years, 47% women, 93% with left ventricular ejection fraction ≤35%) were included. After SNM, changes in systolic blood pressure during Valsalva (peak-to-trough) were greater (41 versus 48 mm Hg, P=0.025). Exercise-induced hemoconcentration was unchanged (0.63 versus 0.43 g/dL, P=0.115). Inferior vena cava diameter was reduced (1.59 versus 1.30 cm, P=0.034) with higher collapsibility (33% versus 73%, P=0.014). Bendopnea was less (47% versus 13%, P=0.025). Conclusions SNM resulted in increased venous capacitance, associated decreased cardiac preload, and decreased bendopnea. Minimally invasive measures of venous capacitance could serve as markers of successful SNM. Long-term effects of SNM on venous capacitance warrant further investigation for heart failure management. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03453151.

Spinal anesthesia does not cause left ventricular dysfunction in patients older than 60 years without cardiovascular disease

BACKGROUND

Elderly patients are undergoing surgery more frequently than ever. In this population, spinal anesthesia, which is known to cause sympathetic blockade associated with arterial vasodilation, is proposed as an excellent option. However, its effects on left ventricular systolic function have not been studied.

OBJECTIVES

To evaluate left ventricular systolic function by transthoracic echocardiography in patients older than 60 years, without prior cardiovascular disease, under spinal anesthesia.

PATIENTS AND METHODS

Prospective observational study with a total of 54 patients older than 60 years without prior cardiovascular disease, in whom, after the completion of subarachnoid anesthesia with hyperbaric 0.5% bupivacaine with sensory block equal to or greater than T10, left ventricular systolic function was measured using MAPSE. In addition, CI-IVC, LVOT-VTI and CO were measured. Values at 5 min after the blockade were compared with those obtained previously.

RESULTS

A 3.3% decrease in MAPSE and a slight decrease in LVOT-VTI and CO were found, with no statistical or clinical significance. 14.8% of the patients presented MAP equal to or less than 60 mmHg. Comparison of echocardiographic changes between hypotensive and non-hypotensive patients was not statistically significant or clinically relevant.

DISCUSSION

Our study shows that spinal anesthesia with anesthetic level T10 or higher in patients older than 60 years without cardiovascular disease is a safe technique since it does not significantly alter echocardiographic parameters measuring left ventricular systolic function.

Inferior vena cava diameter on CT angiography predicts mesenteric angiography positive for extravasation in colonic diverticular bleeding

PURPOSE

Transcatheter arterial embolization (TAE) for colonic diverticular bleeding (CDB), an established procedure for hemostasis, is sometimes complicated by spontaneous hemostasis and unclear bleeding site on angiography despite active arterial bleeding on preoperative computed tomography angiography (CTA). Therefore, to investigate and increase the feasibility of TAE, this retrospective study evaluates the clinical and radiological features related to positive extravasation on angiography.

MATERIAL AND METHODS

Sixty CDB patients with extravasation on CTA underwent TAE between January 2011 and February 2021 and were divided into extravasation-positive (P-group; n = 25) and -negative groups (N-group; n = 35) based on the superior or inferior mesenteric angiography. Patient characteristics, laboratory findings, the diameter of the inferior vena cava (IVCD), the diameter of superior and inferior mesenteric veins, and technical outcomes were evaluated.

RESULTS

TAE was successful in 24 patients in the P-group (96%) and 14 in the N-group (40%) (p < 0.001). Univariate analysis revealed "usage of anticoagulant" (p < 0.05) and "larger IVCD (p < 0.05) on preoperative CTA" to be significant predictors of positive extravasation. In the multivariate analysis, IVCD remained significant with an adjusted odds ratio of 1.17. The IVCD cutoff value was 13.6 mm (area under the curve = 0.72, sensitivity = 84.0%, specificity = 54.3%). There were no significant differences in other parameters.

CONCLUSION

Measurement of IVCD in CDB with the cutoff value of 13.6 mm can be a simple and useful indicator to predict the detectability of extravasation following TAE procedures.

Sensitivity and Reproducibility of Inferior Vena Cava Diameter and Superior Vena Cava Flow Velocity Measurements to Changes in Cardiac Preload in Subjects with Hypertension

Objectives

We investigated the sensitivity and reproducibility of inferior vena cava (IVC) diameters and superior vena cava (SVC) flow velocities in detecting changes in cardiac preload in clinically euvolemic subjects with hypertension.

Methods

Measurements were obtained during passive leg raising (PLR) and lower limb venous occlusion (LVO), interventions which respectively transiently increase and decrease cardiac preload. Measurements were made in 36 subjects and repeated on two separate occasions to examine reproducibility.

Results

During PLR, there was no significant change in IVC diameters, but peak flow velocity of the SVC S wave increased by 6.5 (95% confidence interval 1.6-11.3) cm/s (P = 0.01). During LVO, IVC diameter in expiration decreased by 3.2 (1.7-4.7) mm and the SVC S wave decreased by 9.7 (4.4-14.7) cm/s (P < 0.001). Venae cavae-derived indices can be used to assess changes in preload within the physiological range in euvolemia.

Conclusions

Despite suboptimal reproducibility of baseline measurements, high agreeability between the changes in IVC diameter and SVC flow after LVO suggests that these indices can be used to monitor changes in cardiac preload.

Remote Cardiac Monitoring in Patients With Heart Failure: A Review

Importance

Heart failure (HF) is often characterized by an insidious disease course leading to frequent rehospitalizations and a high use of ambulatory care. Remote cardiac monitoring is a promising approach to detect worsening HF early and intervene prior to an overt decompensation.

Observations

Recently, a multitude of novel technologies for remote cardiac monitoring (RCM) in patients with HF have been developed and are undergoing clinical trials. This development has been accelerated by the COVID-19 pandemic.

Conclusions and Relevance

This review summarizes the major clinical trials on RCM in patients with HF and present the most recent developments in noninvasive and invasive RCM technologies.

Ultrasound-Guided Preload Indices during Different Weaning Protocols of Mechanically Ventilated Patients and its Impact on Weaning Induced Cardiac Dysfunction

BACKGROUND: Elevation of the left ventricular (LV) filling pressure can occur during weaning of mechanical ventilation due to increase in LV preload and/or changes in LV compliance and LV afterload. AIM: The aim of the study was to evaluate respiratory changes in internal jugular vein and inferior vena cava during weaning from mechanical ventilation. METHODS: Prospective observational study conducted on 80 consecutive patients. Patients were divided randomly into two groups who met the readiness criteria to start spontaneous breathing trial (SBT) either on pressure support ventilation (PS/CPAP) for 30 min or T-piece for 120 min. Weaning failure was defined as a failed SBT or reintubation within 48 h. Echocardiographic evaluation was done on assisted controlled ventilation and at the end of SBT for preload assessment. RESULTS: Mitral Septal E/E’ Cutoff value ≥6.1 with sensitivity 81% and specificity 84.2%, and AUC 0.73 for predicting weaning failure. IVC distensibility index on CPAP cutoff value ≥66.5% with sensitivity 100% and specificity 68.4%, and AUC 0.85. In Group II, Mitral Septal E/E’ Cut off value ≥5.8 with sensitivity 83% and specificity 90.9%, AUC 0.83, IVC collapsibility index Cut off value ≥45.5% with sensitivity 72% and specificity 86%, AUC 0.73. CONCLUSION: Mitral Septal E/E’ could predict weaning-induced diastolic dysfunction. IVC plays an important role in predicting weaning failure.

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.

Non-invasive Assessment of Intravascular Volume Status for Postoperative Patients: The Correlation Between the Internal Jugular Vein/Common Carotid Artery Cross-sectional Area Ratio and the Inferior Vena Cava Diameter

Background

This study aimed to assess the correlation between the internal jugular vein/common carotid artery (IJV/CCA) cross-sectional area (CSA) ratio and the inferior vena cava (IVC) diameter as non-invasive techniques for the assessment of intravascular volume.

Methods

The study samples included 35 adult patients of both sexes (age range: 20 - 60 years) according to the criteria of the American Society of Anaesthesiology (ASA) physical status II - III, who were admitted to the surgical intensive care unit (SICU) after major surgeries for the assessment of intravascular volume status.

Results

There was a positive correlation between the IJV/CCA CSA ratio and the IVC maximum and minimum diameter before and after fluid infusion (r = 0.923, P < 0.001 and r = 0.390, P = 0.021, respectively) and between the IJV/CCA CSA ratio at inspiration and the IVC minimum diameter before and after fluid infusion (r = 0.605, P < 0.001 and r = 0.496, P < 0.001, respectively). The sensitivity and specificity analysis of the IJV/CCA CSA during inspiration after fluid correction to predict a central venous pressure (CVP) of 8 - 12 cmH₂O showed that at a ratio of 2.56, the highest sensitivity was 56.5%, and the specificity was 83.3%; at a ratio of 2.58, the highest sensitivity was 65.2% and the specificity was 75%. During expiration, at a ratio of 2.62, the highest sensitivity was 52.2%, and the specificity was 67%; and at a ratio of 2.65, the sensitivity was 56.5%, and the specificity was 50%.

Conclusions

The assessment of the IJV/CCA CSA ratio using bedside ultrasound could be a non-invasive tool for the evaluation of intravascular volume status in spontaneously breathing adult patients after major surgeries.

Can Inferior Vena Cava Diameter and Collapsibility Index Be a Predictor in Detecting Preoperative Intravascular Volume Change in Pediatric Patients?

Background: Inferior vena cava (IVC) ultrasound measurement is a reliable indicator used in the assessment of intravascular volume status. The aim of this study was to evaluate intravascular volume changes in pediatric patients by measuring the IVC diameter and collapsibility index (CI) in children whose oral feeding was restricted preoperatively. Material and Methods: From May 2018 to October 2018, a total of 55 pediatric patients who were scheduled for surgery were included in this prospective, observational, cohort study. Fasting and satiety IVC diameters and CIs of patients were determined by ultrasonographic evaluation twice: in the preoperative preliminary evaluation, when the patients were satiated, and before surgery, during a fasting period of 6–8 hours. Ultra-sonographic data were recorded and compared between fasting and satiety periods. Results: In the grey scale (B-mode), mean IVC diameter was significantly higher when the patients were satiated, compared to the measurements made just before surgery during the fasting period. In the M-mode, the mean IVC diameter was significantly higher only during the inspiratory phase when the patients were satiated, while during the expiratory phase it was detected to be statistically similar. Mean CI was significantly higher in the immediate preoperative period, compared to the assessment made when satiated. Conclusion: Preoperative ultrasound IVC diameter and CI measurement can be a practical and useful method for evaluating preoperative intravascular volume in children.

Optimal management of brain-dead organ donor

Maintaining a brain stem-dead (BSD) donor is specialized science. It is a daunting task as they are fragile patients who need to be handled with utmost care owing to extreme haemodynamically instability and need the best of monitoring for maintenance of organs. To ensure a successful transplant, a BSD donor first needs to be identified on time. This requires scrupulous monitoring of neurologically compromised patients who tend to be the most frequent organ donors. Once the donor is identified, an all-out effort should be made to legally obtain consent for the donation. This may require numerous sessions of counselling of the relatives. It needs to be performed tactfully, displaying the best of intentions. It is important to understand the physiology of a brain-dead individual. A cascade of changes occurs in BSD donor which result in a catastrophic plummeting of the clinical condition of the donor. All organ systems are involved in this clinical chaos, and best possible clinical support of all organ systems should be available and extended to the donor. Organ support includes cardiovascular, pulmonary, temperature, glycaemic, metabolic and hormonal. This article has been written as a follow-up article of previously published article on identifying an organ donor. It intends to give the reader a concept of what the BSD donor undergoes after brain death and as to how to maintain and preserve various organs for donation for successful transplantation of maximum organs.

The Relation Between Common Carotid Artery Diameter and Central Venous Pressure for Assessment of Intravascular Fluid Status after Major Surgeries; an Observational Study

Objectives

The current study aimed to find the relation between the changes in the common carotid artery (CCA) diameter and the central venous pressure (CVP) in response to a fluid challenge in spontaneously breathing adult patients.

Methods

This study included 65 adult patients aged 20 - 60 years who were admitted to the surgical ICU. The CCA diameter and CVP were measured before and after fluid challenge, and the percentage of increase in the CCA diameter and CVP were calculated. The correlation was assessed between changes in the CVP and CCA diameter.

Results

The CCA diameter before fluid administration had a significant strong positive correlation to the CVP (r = 0.8, P value < 0.001); the increase in the CCA diameter after fluid administration had a significant moderate positive correlation with the increase in the CVP (r = 0.4, P value < 0.001). The percentage of increase in CCA diameters was positively correlated to the percentage of increase in CVP (r = 0.589, P value = 0.001) following fluid administration. However, the Receiver Operating Characteristic (ROC) analysis was an invalid test (area under curve 0.513, P value = 0.885).

Conclusions

After major surgeries, the change in the CCA diameter was positively correlated with the change in the CVP values in response to fluid administration in the spontaneously breathing adult patients, but the cut-off limit cannot be reached.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

General Pediatric Clinical Applications of POCUS: Part 2

The use of point-of-care ultrasound (POCUS) performed by non-radiologists has become more widespread and is entering new arenas of clinical care, particularly in the world of pediatrics. Children are prime candidates for ultrasound because they are more at risk to the harmful effects of ionizing radiation than adults. This is the second part of a two-part article reviewing 10 uses of POCUS that pediatricians can apply to their practice in both inpatient and outpatient settings. [Pediatr Ann. 2020;49(4):e196-e200.].

Sonographic Assessment of Intravascular Fluid Estimate (SAFE) Score by Using Bedside Ultrasound in the Intensive Care Unit

Objective

The objective of the study was to use an ultrasound-based numerical scoring system for assessment of intravascular fluid estimate (SAFE) and test its validity.

Methods

A prospective, observational study was carried out in the surgical intensive care unit (ICU) of an urban tertiary care teaching hospital. Patient's intravascular volume status was assessed using the standard methods of heart rate, blood pressure, central venous pressure, cardiac output, lactate and saturation of venous oxygen, and others. This was compared with assessment using bedside ultrasound evaluation of the cardiac function, inferior vena cava, lungs, and the internal jugular vein. Applying a numerical scoring system was evaluated by Fisher's exact testing and multinomial logistic model to predict the volume status based on ultrasound scores and the classification accuracy.

Results

61 patients in the ICU were evaluated. 21 (34.4% of total) patients diagnosed with hypovolemia, and their ultrasound volume score was −4 in 14 (66.7%) patients, −3 in 5 (23.8%) patients, and 0 in 2 (9.5%) patients (p < 0.001). 18 (29.5% of total) patients diagnosed with euvolemia, and their ultrasound volume score was 0 in 11 (61.1%) patients, +1 in 4 (22.2%) patients, and −1 in 1 (5.6%) patient (p < 0.001). 18 (29.5% of total) patients diagnosed with euvolemia, and their ultrasound volume score was 0 in 11 (61.1%) patients, +1 in 4 (22.2%) patients, and −1 in 1 (5.6%) patient (p < 0.001). 18 (29.5% of total) patients diagnosed with euvolemia, and their ultrasound volume score was 0 in 11 (61.1%) patients, +1 in 4 (22.2%) patients, and −1 in 1 (5.6%) patient (p < 0.001). 18 (29.5% of total) patients diagnosed with euvolemia, and their ultrasound volume score was 0 in 11 (61.1%) patients, +1 in 4 (22.2%) patients, and −1 in 1 (5.6%) patient (

Conclusion

Using the SAFE scoring system to identify the IVV status in critically ill patients significantly correlates with the standard measures. A SAFE score of −4 to −2 more likely represents hypovolemia, −1 to +1 more likely represents euvolemia, and +2 to +4 more likely to be hypervolemia.

Comparison of inferior vena cava collapsibility, distensibility, and delta indices at different positive pressure supports and prediction values of indices for intravascular volume status

Background/aim

To compare the inferior vena cava (IVC) indices, identify their variation rates at positive pressure values and accurate predictive values for the volume status in patients with spontaneous respiration receiving different positive pressure support.

Material and methods

The study included 100 patients who were divided into 4 pressure support groups, according to the different pressure supports received, and 3 volume groups according to their CVP values. Ultrasonography was applied to all of the patients to define their IVC diameters at different pressure supports. Dynamic parameters were derived from the ultrasonographic assessment of the IVC diameter [collapsibility (CI-IVC), distensibility (dIVC), and delta (ΔIVC) indices].

Results

There were significant differences between the 3 indices (CI-IVC, dIVC, and ΔIVC) according to the pressure groups [(10/5), (10/0), (0/5), (t tube 0/0)]. The median value for the dIVC percentages was ≤18% for all of the positive pressure support hypervolemic groups, apart from the hypervolemic t tube group (19%). For the hypervolemic groups, the best estimation according to the cut-off value appeared to be for the dIVC. Values with the highest sensitivity for differentiation of the hypovolemic individuals were calculated with the dIVC.

Conclusion

The dIVC had a more accurate predictive role in predicting the volume status when compared with the CI-IVC and ΔIVC, and may be used reliably with positive pressure supports.

Maternal Venous Hemodynamic Dysfunction in Proteinuric Gestational Hypertension: Evidence and Implications

This review summarizes current knowledge from experimental and clinical studies on renal function and venous hemodynamics in normal pregnancy, in gestational hypertension (GH) and in two types of preeclampsia: placental or early-onset preeclampsia (EPE) and maternal or late-onset (LPE) preeclampsia, presenting at <34 weeks and ≥34 weeks respectively. In addition, data from maternal venous Doppler studies are summarized, showing evidence for (1) the maternal circulation functioning closer to the upper limits of capacitance than in non-pregnant conditions, with intrinsic risks for volume overload, (2) abnormal venous Doppler measurements obtainable in preeclampsia, more pronounced in EPE than LPE, however not observed in GH, and (3) abnormal venous hemodynamic function installing gradually from first to third trimester within unique pathways of general circulatory deterioration in GH, EPE and LPE. These associations have important clinical implications in terms of screening, diagnosis, prevention and management of gestational hypertensive diseases. They invite for further hypothesis-driven research on the role of retrograde venous congestion in the etiology of preeclampsia-related organ dysfunctions and their absence in GH, and also challenge the generally accepted view of abnormal placentation as the primary cause of preeclampsia. The striking similarity between abnormal maternal venous Doppler flow patterns and those observed at the ductus venosus and other abdominal veins of the intra-uterine growth restricted fetus, also invites to explore the role of venous congestion in the intra-uterine programming of some adult diseases.

The utility of point-of-care ultrasound in the assessment of volume status in acute and critically ill patients

BACKGROUND

Volume resuscitation has only been demonstrated to be effective in approximately fifty percent of patients. The remaining patients do not respond to volume resuscitation and may even develop adverse outcomes (such as acute pulmonary edema necessitating endotracheal intubation). We believe that point-of-care ultrasound is an excellent modality by which to adequately predict which patients may benefit from volume resuscitation.

DATA RESOURCES

We performed a search using PubMed, Scopus, and MEDLINE. The following search terms were used: fluid responsiveness, ultrasound, non-invasive, hemodynamic, fluid challenge, and passive leg raise. Preference was given to clinical trials and review articles that were most relevant to the topic of assessing a patient's cardiovascular ability to respond to intravenous fluid administration using ultrasound.

RESULTS

Point-of-care ultrasound can be easily employed to measure the diameter and collapsibility of various large vessels including the inferior vena cava, common carotid artery, subclavian vein, internal jugular vein, and femoral vein. Such parameters are closely related to dynamic measures of fluid responsiveness and can be used by providers to help guide fluid resuscitation in critically ill patients.

CONCLUSION

Ultrasound in combination with passive leg raise is a non-invasive, cost- and time-effective modality that can be employed to assess volume status and response to fluid resuscitation. Traditionally sonographic studies have focused on the evaluation of large veins such as the inferior vena cava, and internal jugular vein. A number of recently published studies also demonstrate the usefulness of evaluating large arteries to predict volume status.

Measurement of Internal Jugular Vein and Common Carotid Artery Diameter Ratio by Ultrasound to Estimate Central Venous Pressure

Objective

The objective of this study is to find a correlation between internal jugular vein (IJV) and common carotid artery (CCA) diameter ratio and central venous pressure (CVP) measurement and find a cut-off value for the IJV/CCA ratio to predict low CVP i.e. < 10 cm H₂0, for estimating the volume status in critically ill patients.

Methods

This prospective cross-sectional study was conducted at the critical care department of Shifa International Hospital, Islamabad, from July to December 2017. A sample of 49 patients ≥ 18 years with intrathoracic central venous catheters (CVCs) who underwent bedside sonographic assessments of IJV and CCA diameter were included in this study using convenient sampling. The IJV/CCA diameter ratio was calculated and correlated with CVP and the predictive value of the IJV/CCA diameter ratio to predict CVP < 10 cm H₂O was explored by calculating the area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, and positive and negative predictive values.

Results

A total of 49 patients, 30 males (61.2%) and 19 females (38.8%) with a mean age of 56.00±16.11 years were included in the study. The mean CVP was 8.98±2.37cm H₂O in ventilated (51%) and 10.7± 6.01 cm H₂O in non-ventilated (49%) patients. The mean IJV/CCA diameter ratio was 1.60±0.55 at expiration and 1.41±0.56 at inspiration. There was a significant correlation between the IJV/CCA diameter ratio and CVP at expiration (r=0.401, p=0.004). The correlation between IJV/CCA and CVP was significant in non-ventilated patients at expiration (r=0.439, p=0.032). The area under the ROC curve for the IJV/CCA diameter ratio for predicting CVP < 10 cm H₂O was 0.684 (p=0.028). The predictive value of the IJV/CCA diameter ratio for CVP < 10 cm H₂0 at the cutoff value of < 2 was insignificant. A new cut-off < 1.75 was taken for the IJV/CCA diameter ratio from the coordinates of the ROC curve. The sensitivity, specificity, PPV, and NPV of an IJV/CCA diameter ratio of < 1.75 for predicting a CVP < 10 cm H₂0 were 84.62%, 52.17%, 66.67%, and 75.00%, respectively.

Conclusion

The assessment of volume status by the IJV/CCA diameter ratio with a sonographic device may be a useful noninvasive alternative for a central venous catheterization with a cut-off < 1.75.

Competence of Intensivists in Focused Transthoracic Echocardiography in Intensive Care Unit: A Prospective Observational Study

Objectives:

Focused transthoracic echocardiography (fTTE) in critical care can be used to assess patient's volume status, ventricular contractility, right ventricle chamber size, and valvular abnormalities. The objective of the study was to assess the competency of intensivists in performing fTTE in Intensive Care Unit (ICU) patients after a brief training course by cardiologist using a specific ECHO protocol.

Methods:

One hundred and four patients in ICU were recruited for this prospective observational study over a period of 12 months. Intensivists were trained for 60 h (2 h/day for 30 days). Intensivists performed fTTE in 82 ICU patients using a specific ECHO protocol developed in consensus with cardiologists. Each patient was assessed by an intensivist and two blinded cardiologists. At the end of the study period, the competency of intensivists was compared with two cardiologists and analyzed using intraclass correlation coefficient (ICC).

Results:

There were excellent agreement between intensivists and cardiologists in terms of measuring ejection fraction (ICC estimate was 0.973–0.987), valvular function (ICC estimate for mitral valve was 0.940–0.972; ICC estimate for aortic valve was 0.872–0.940), and ICC estimate for pulmonary hypertension was 0.929–0.967. Good reliability has been found for the assessment of volume status with inferior vena cava diameter (ICC estimate for assessing hypovolemia was 0.790–0.902).

Conclusion:

Intensivists with requisite training in TTE were able to perform focused echocardiography with comparable accuracy to that of cardiologists. Further studies are required to elucidate the therapeutic implications of fTTE performed by the intensivists.