Simultaneous Venous-Arterial Doppler Ultrasound During Early Fluid Resuscitation to Characterize a Novel Doppler Starling Curve: A Prospective Observational Pilot Study.

Background: The likelihood of a patient being preload responsive-a state where the cardiac output or stroke volume (SV) increases significantly in response to preload-depends on both cardiac filling and function. This relationship is described by the canonical Frank-Starling curve. Research Question: We hypothesize that a novel method for phenotyping hypoperfused patients (ie, the "Doppler Starling curve") using synchronously measured jugular venous Doppler as a marker of central venous pressure (CVP) and corrected flow time of the carotid artery (ccFT) as a surrogate for SV will refine the pretest probability of preload responsiveness/unresponsiveness. Study Design and Methods: We retrospectively analyzed a prospectively collected convenience sample of hypoperfused adult emergency department (ED) patients. Doppler measurements were obtained before and during a preload challenge using a wireless, wearable Doppler ultrasound system. Based on internal jugular and carotid artery Doppler surrogates of CVP and SV, respectively, we placed hemodynamic assessments into quadrants (Qx) prior to preload augmentation: low CVP with normal SV (Q1), high CVP and normal SV (Q2), low CVP and low SV (Q3) and high CVP and low SV (Q4). The proportion of preload responsive and unresponsive assessments in each quadrant was calculated based on the maximal change in ccFT (ccFTΔ) during either a passive leg raise or rapid fluid challenge. Results: We analyzed 41 patients (68 hemodynamic assessments) between February and April 2021. The prevalence of each phenotype was: 15 (22%) in Q1, 8 (12%) in Q2, 39 (57%) in Q3, and 6 (9%) in Q4. Preload unresponsiveness rates were: Q1, 20%; Q2, 50%; Q3, 33%, and Q4, 67%. Interpretation: Even fluid naïve ED patients with sonographic estimates of low CVP have high rates of fluid unresponsiveness, making dynamic testing valuable to prevent ineffective IVF administration.

The predictive role of carotid artery flow time for anesthesia-induced hypotension in high-risk elderly patients.

Hypotension induced by general anesthesia is associated with postoperative complications, increased mortality, and morbidity, particularly elderly patients. The aim of this study was to investigate the effectiveness of corrected carotid artery flow time (FTc) for predicting hypotension following anesthesia induction in patients over 65 years old. After faculty ethical committee approval and written informed consent, 138 patients (65 years and older, ASA physical status I-III) who scheduled for elective surgery were included in this study. In the pre-operative anesthesia unit, the carotid artery FTc value was measured by ultrasound and hemodynamic values were recorded. Following anesthesia induction with propofol, hemodynamic data were recorded at 1-minute intervals for 3 min. Measurements were terminated prior to endotracheal intubation, as direct laryngoscopy and endotracheal intubation could cause sympathetic stimulation and hemodynamic changes. Hypotension occurred in 52 patients (37.7%). The preoperative FTc value of the patients who developed hypotension was statistically lower (312.5 ms) than the patients who did not (345.0 ms) (p < 0.001). The area under the ROC curve for carotid artery FTc was 0.93 (95% CI for AUC:0.89-0.97; p < 0.001) with an optimal cut-off of value for predicting post-anesthesia hypotension 333 ms, a sensitivity of 90.4% and a specificity of 84.9%. As a result of the multiple logistic regression model, carotid artery FTc emerged as the sole independent risk factor for hypotension following anesthesia induction. Preoperative carotid artery FTc measurement is a simple, bedside, noninvasive, and reliable method for predicting anesthesia-induced hypotension in elderly patients.

Pitfalls in Carotid Doppler Interpretation and How to Avoid Them.

Imaging pitfalls commonly occur in carotid Doppler ultrasound and may lead to false positive diagnosis of stenosis, missed diagnosis of stenosis, and errors in grading stenosis severity. These pitfalls may result from suboptimal technique and/or patient-specific factors including coexisting cardiovascular pathology, contralateral high-grade stenosis/occlusion, tortuous vessels, tandem lesions, long-segment stenosis, nearly occlusive stenosis, and heavily calcified plaque. Awareness of these pitfalls and careful assessment of the extent of plaque on grayscale and color Doppler as well as analysis of the spectral Doppler waveforms can help avoid misinterpretation of the carotid Doppler examination.

Carotid artery corrected flow time and respiratory variations of peak blood flow velocity for prediction of hypotension after induction of general anesthesia in elderly patients.

BACKGROUND: Postinduction hypotension is closely related to postoperative complications. Elderly patients with compromised cardiovascular compensatory reserve are more susceptible to hypotension after induction of general anesthesia. This study investigated whether the carotid artery corrected flow time (FTc) and respiratory variation of peak blood flow velocity in the common carotid artery (ΔVpeak) could predict postinduction hypotension in elderly patients. METHODS: This prospective observational study included elderly patients aged 65 to 75 who were scheduled for elective surgery under general anesthesia with ASA physical status class of I-II, without cardiovascular disease, hypertension, diabetes, or obesity. Anesthesia was induced by midazolam, sufentanil, and etomidate and was maintained by sevoflurane. The carotid artery FTc and ΔVpeak were measured by ultrasound before induction of anesthesia. Hemodynamic data were recorded before induction and then during the first 10 min after induction. RESULTS: Ninety-nine patients were included in the final analysis, of whom 63 developed postinduction hypotension. The area under the receiver operating characteristic curves was 0.87 (0.78 to 0.93) for carotid artery FTc and 0.67 (0.56 to 0.76) for ΔVpeak, respectively. The optimal cutoff value for predicting postinduction hypotension was 379.1 ms for carotid artery FTc, with sensitivity and specificity of 72.2 and 93.7%, respectively. The best cutoff value was 7.5% for ΔVpeak, with sensitivity and specificity of 55.6 and 75.0%, respectively. CONCLUSIONS: The carotid artery FTc is a reliable predictor of postinduction hypotension in elderly patients with ASA status of I or II, without cardiovascular disease, hypertension, diabetes, or obesity. Elderly patients with a carotid artery FTc less than 379.1 ms before anesthesia have a higher risk of postinduction hypotension. TRIAL REGISTRATION: Clinical Trial Registry on August 2nd, 2020 ( www.chictr.org.cn ; ChiCTR2000035190).

Correlation of carotid corrected flow time and respirophasic variation in blood flow peak velocity with stroke volume variation in elderly patients under general anaesthesia.

BACKGROUND: Accurate assessment of volume responsiveness in elderly patients is important as it may reduce the risk of post-operative complications and enhance surgical recovery. This study evaluated the utility of two Doppler ultrasound-derived parameters, the carotid corrected flow time (FTc) and respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak), to predict volume responsiveness in elderly patients under general anaesthesia. METHODS: A total of 97 elderly patients undergoing elective abdominal surgery under general anaesthesia were enrolled in this prospective observational study. After entering the operating room, all patients underwent radial artery puncture connected with a LiDCO device to measure stroke volume variation (SVV), and fluid therapy was performed after anaesthesia induction. Patients were classified as responders if SVV ≥ 13% before fluid challenge and nonresponders if SVV < 13%. The FTc, ΔVpeak, SVV and haemodynamic data were measured by ultrasound at baseline (T0) and before (T1) and after (T2) fluid challenge. The correlations between the Doppler ultrasound-derived parameters and SVV were analysed, and the receiver operating characteristic (ROC) curves was computed to characterize both FTc and ΔVpeak as measures of volume responsiveness in elderly patients. RESULTS: Forty-one (42.3%) patients were fluid responders. Carotid FTc before fluid challenge was negatively correlated with SVV before fluid challenge (r = -0.77; P < 0.01), and ΔVpeak was positively correlated with SVV (r = 0.72; P < 0.01). FTc and ΔVpeak predicted SVV ≥ 13% after general anaesthesia in elderly patients, with areas under the receiver operating characteristic curves (AUROCs) of 0.811 [95% confidence interval (CI), 0.721-0.900; P < 0.001] and 0.781 (95% CI, 0.686-0.875; P < 0.001), respectively. The optimal cut-off values of FTc and ΔVpeak to predict SVV ≥ 13% were 340.74 ms (sensitivity of 76.8%; specificity of 80.5%) and 11.69% (sensitivity of 78.0%; specificity of 67.9%), respectively. CONCLUSIONS: There was a good correlation between carotid artery ultrasound parameters and SVV. FTc predicted fluid responsiveness better than ΔVpeak in elderly patients during general anaesthesia. Further study is needed before these parameters can be recommended for clinical application. TRIAL REGISTRATION: www.chictr.org.cn (ChiCTR2000031193); registered 23 March 2020.

Correlation of Carotid Doppler Blood Flow With Invasive Cardiac Output Measurements in Cardiac Surgery Patients.

OBJECTIVE: Carotid Doppler ultrasound has been a topic of recent interest, as it may be a promising noninvasive hemodynamic monitoring tool. In this study, the relation between carotid artery blood flow and invasive cardiac output (CO) was evaluated. DESIGN: A prospective, observational study. SETTING: A single-institution, tertiary referral hospital. PARTICIPANTS: Eighteen elective cardiac surgery patients. INTERVENTIONS: CO was measured by calibrated pulse contour analysis. Simultaneously, carotid artery pulsed-wave Doppler measurements were obtained in the operating room in three clinical settings: after induction of anesthesia (T1), after a passive leg raise maneuverer (T2), and at the end of surgery (T3). MEASUREMENTS AND MAIN RESULTS: Correlation and trending between carotid artery blood flow and invasive CO were evaluated. Furthermore, two Bland-Altman plots were constructed to evaluate the level of agreement between carotid artery-derived CO and invasive CO measurements. Carotid artery blood flow correlated moderately with invasive CO (ρ = 0.67, 95% confidence interval 0.56-0.76, p < 0.05). Concordance between the percentage change of carotid artery blood flow and invasive CO from T1 to T3 was 72%. The level of agreement between carotid artery-derived CO and invasive CO was ±2.29; ±2.57 L/min, with a bias of 0.1; -0.54 L/min, and mean error of 50% and 48%, for the two Bland-Altman analyses, respectively. Intraexamination precision was acceptable. CONCLUSIONS: In cardiac surgery patients, carotid artery blood flow correlated moderately with invasive CO measurements. However, the trending ability of carotid artery blood flow was poor, and carotid artery-derived CO tended not to be interchangeable with invasive CO.

Correlation of carotid Doppler flowmetry with fluid responsiveness in mechanically ventilated patients undergoing coronary artery bypass grafting-A popular gray zone.

The authors conducted a prospective, observational study to evaluate the correlation of fluid responsiveness with commonly used carotid Doppler-derived indices like carotid artery blood flow, carotid corrected flow time, respirophasic variation in carotid artery blood flow peak velocity in patients undergoing coronary artery bypass grafting. They claimed that altough only ΔVpeak demonstrated some predictive power with areas under receiver operating characteristic of 0.671, carotid Doppler ultrasound indices were found to be not dependable as a substitute for invasive methods to assess fluid responsiveness. The presence of studies advocating quite different sentiments in the literature regarding feasibility and reliability show that there is a long way gone and a long way to go.

Functional Hemodynamic Monitoring With a Wireless Ultrasound Patch.

In this Emerging Technology Review, a novel, wireless, wearable Doppler ultrasound patch is described as a tool for resuscitation. The device is designed, foremost, as a functional hemodynamic monitor-a simple, fast, and consistent method for measuring hemodynamic change with preload variation. More generally, functional hemodynamic monitoring is a paradigm that helps predict stroke volume response to additional intravenous volume. Because Doppler ultrasound of the left ventricular outflow tract noninvasively measures stroke volume in realtime, it increasingly is deployed for this purpose. Nevertheless, Doppler ultrasound in this manner is cumbersome, especially when repeat assessments are needed. Accordingly, peripheral arteries have been studied and various measures from the common carotid artery Doppler signal act as windows to the left ventricle. Yet, handheld Doppler ultrasound of a peripheral artery is susceptible to human measurement error and statistical limitations from inadequate beat sample size. Therefore, a wearable Doppler ultrasound capable of continuous assessment minimizes measurement inconsistencies and smooths inherent physiologic variation by sampling many more cardiac cycles. Reaffirming clinical studies, the ultrasound patch tracks immediate SV change with excellent accuracy in healthy volunteers when cardiac preload is altered by various maneuvers. The wearable ultrasound also follows jugular venous Doppler, which qualitatively trends right atrial pressure. With further clinical research and the application of artificial intelligence, the monitoring modalities with this new technology are manifold.

Respiratory Fluctuation of Peak Systolic Velocities in the Carotid Doppler Waveforms of Patients With Obstructive Airway Disease: Evidence of Pulsus Paradoxus With Experimental Validation.

OBJECTIVES: To characterize fluctuations in peak systolic velocities (PSVs) in Doppler waveforms of the carotid artery in patients with and without obstructive airway disease and in volunteers subjected to incremental levels of airway resistance in an experimental model. METHODS: The PSV variation in common carotid waveforms was measured in 100 patients who had had a carotid ultrasound examination and no respiratory or carotid disease. This was compared to that of patients who had this study during an admission for acute exacerbation of chronic obstructive pulmonary disease (COPD). The PSV variation was correlated with pulmonary function testing. In addition, 14 healthy volunteers were asked to breathe through 5 resistors. Simultaneous recordings were made of Doppler waveforms in the common carotid artery, cardiac activity, and respiration. Peak systolic velocity changes from inspiration to expiration were calculated. RESULTS: Of the 100 patients without respiratory disease, the magnitude of the PSV variation averaged 6.3 cm/s. Of the 33 patients with COPD, the PSV variation averaged 16.5 cm/s. Nineteen of the 33 patients with COPD had concurrent pulmonary function testing; there was a statistically significant correlation between the PSV variation and forced vital capacity and forced expiratory volume indices. For the volunteers, mean velocity changes were 7.1, 6.6, 8.3, 15.1, and 16.1 cm/s for 0.00-, 2.15-, 3.27-, 3.58-, and 5.77-cm H2 O/L/s levels of breathing resistance, respectively. There was a statistically significant relationship between an increasing airway load and the decline in PSV during inspiration (P = .02). CONCLUSIONS: The PSV variation is greater in patients with increased airway resistance. Similar changes are evident in volunteers breathing into resistors. These findings likely reflect pulsus paradoxus.

Carotid Doppler ultrasonographic findings of dapagliflozin use in type 2 diabetic patients.

AIM: Sodium-glucose cotransporter 2 inhibitors have been shown to reduce the risk of cardiovascular disease in type 2 diabetes (T2DM) patients. The purpose of this study was to evaluate cardiovascular disease risk indirectly through Doppler ultrasonography (USG) of carotid artery vascular markers in T2DM patients using dapagliflozin. METHODS: One hundred forty-five patients presenting to our clinic between March 2016 and June 2018 and diagnosed with T2DM were included in the study. These were divided into two groups - a dapagliflozin group of 85 patients and a 60-member non-dapagliflozin control group. Common carotid artery end-diastolic velocity (EDV), peak systolic velocity (PSV), and resistive index (RI) parameters were evaluated using Doppler USG in both groups. RESULTS: The mean duration of follow-up was 2.2 ± 0.4 years. Mean ages were 45 ± 14 years in the dapagliflozin group and 42 ± 15 in the control group. Mean HbA1c was 7.4 ± 1.6 in the dapagliflozin group and 7.3 ± 2.1 in the control group. Common carotid artery, PSV, and EDV parameters were higher (p = .012/p = .036), while RI was lower (p ˂ .001), in the dapagliflozin group than in the control group. CONCLUSION: Vascular resistance was lower in the group using dapagliflozin for diabetes management.

Carotid Artery Corrected Flow Time and Respiratory Variations of Peak Blood Flow Velocity for Prediction of Hypotension After Induction of General Anesthesia in Adult Patients Undergoing Elective Surgery: A Prospective Observational Study.

OBJECTIVES: Hypotension is common after induction of general anesthesia, and intraoperative hypotension is associated with postoperative end-organ injury such as acute kidney injury and myocardial ischemia. This study was designed to determine the utility of the carotid corrected flow time (cFT) and carotid artery peak blood flow velocity variation (ðVpeak ) for prediction of hypotension after induction of general anesthesia. METHODS: Adult patients (n = 112) undergoing any elective surgery under general anesthesia who fasted for at least 6 to 8 hours were recruited in this prospective observational study. The common carotid artery cFT and ðVpeak were measured with ultrasound 10 minutes before induction of general anesthesia. After that, general anesthesia with propofol was used, and hemodynamic data were collected until 3 minutes after induction of anesthesia. RESULTS: The carotid cFT was significantly correlated with percentages of the fall in the systolic blood pressure at 2 minutes (P < .0001) and 3 minutes (P < .0001) and percentages of the fall in the mean arterial pressure at 1 minute (P = .0006), 2 minutes (P < .0001), and 3 minutes (P < .0001). The cFT was a predictor of hypotension after induction of general anesthesia, with an area under the receiver operating characteristic curve of 0.91. The best cutoff value obtained from this study was 330.2 milliseconds or less, which predicted postinduction hypotension with sensitivity and specificity of 85.7% and 96.8%, respectively. The ðVpeak was an inferior predictor of postinduction hypotension, with an area under the receiver operating characteristic curve of 0.68. The optimum cutoff value was 18.8%, with sensitivity and specificity of 61.9% and 67.4%. CONCLUSIONS: The cFT measured in the common carotid artery is a reasonable predictor of hypotension after induction of general anesthesia in American Society of Anesthesiologists physical status I and II patients. Further studies are required to identify its role in high-risk patients such as older groups and patients with cardiovascular diseases and also to identify interobserver and intraobserver variability of cFT and ðVpeak measurements.

Concordance and prevalence of subclinical atherosclerosis in different vascular territories.

BACKGROUND: Subclinical atherosclerosis (SA) in the carotid, femoral, and coronary territories is a powerful predictor of cardiovascular (CV) events. Whether it is sufficient to assess SA in a single vascular territory in early-stage disease is uncertain. We aimed to determine the prevalence and concordance of SA in these vascular beds in asymptomatic patients without known CV disease. METHODS: We enrolled patients aged 35 to 75 years who were asymptomatic, without known CV disease, and had undergone carotid and femoral Doppler ultrasonography and calcium scoring. Those receiving statins were excluded. SA was defined as the presence of plaques in the carotid and/or femoral arteries or the presence of calcium in the coronary arteries (Agatston score >0). RESULTS: A total of 212 patients were identified with a mean age of 53 ± 7 years, of which 60% (128 patients) were men. The prevalence of SA was 62%. The distribution of SA between the three territories was similar, involving the carotid territory in 38% of cases, the femoral in 31%, and the coronaries in 37%. The concordance between the different vascular territories was weak, with a k index of 0.21 between the coronary and carotid territories, 0.27 between the coronary and femoral territories, and 0.34 between the carotid and femoral territories. CONCLUSIONS: The prevalence of SA in asymptomatic patients without known CV disease is high. The concordance in the presence of SA between the three vascular territories is weak. Therefore, all three vascular beds need to be investigated.

Is carotid screening redundant for patients undergoing coronary artery bypass grafting?

OBJECTIVES: Stroke is a devastating complication following coronary artery bypass grafting, which thankfully occurs with low incidence. The role of preoperative carotid ultrasound remains unclear. Whilst it is a cheap and reliable way of diagnosing carotid stenosis (CS), it is unclear if and how this knowledge should impact on subsequent patient management. METHODS: A systematic review of the literature was performed using the PRISMA guideline. A literature search was conducted on the MEDLINE database from 1950 to May 2020 using the OVID interface. Fifteen papers out of a total of 5931 were identified for inclusion. RESULTS: The evidence overall suggests that patients with severe CS are likely to have an increased incidence of postoperative stroke-however, the prevalence of severe CS is low, and even in this cohort of patients, the incidence is not particularly high. CONCLUSION: In screened patients identified to have severe CS, there appears to be a generally low appetite for undertaking carotid intervention internationally either before or concurrently with the coronary artery bypass grafting. Putting this all together, the widespread screening of asymptomatic patients would appear to not be justified.

Sonographic Clue in Non-traumatic Carotid-cavernous Fistula: Report of a Case and Literature Review.

BACKGROUND: Failure to recognize a carotid-cavernous fistula (CCF) promptly may lead to worse prognosis due to a setback in providing proper treatment. To promote early diagnosis of non-traumatic CCF, we report a case with classic clinical symptoms and signs that was diagnosed and followed up with carotid Doppler sonography (CDS) and transcranial color-coded duplex (TCD). CASE REPORT: A 45-year-old woman developed an intermittent headache, pulsatile tinnitus, and double vision sequentially within ten days. Progressive left retro-orbital pain, continuous ringing in the left ear, sensory impairment of trigeminal nerve and abducens nerve palsy were also noted on examination. Despite insignificant findings on computed tomography (CT) of the brain, TCD revealed an aberrant flow pattern with high velocity and low resistance at the left carotid siphon. Digital subtraction angiography (DSA) later confirmed a left direct type CCF by illustrating a quick opacification of left cavernous sinus via the internal carotid artery. CONCLUSION: In addition to invasive DSA, non-invasive CDS and TCD may serve as useful apparatus during the initial evaluation and subsequent follow-ups. The positive sonographic clues, including abnormal turbulent and hemodynamic parameters, are quite exhibitive in the existence of CCFs.

Ultrasound Assessment of Extracranial Carotids and Vertebral Arteries in Acute Cerebral Ischemia.

Assessing ischemic etiology and mechanism during the acute phase of an ischemic stroke is crucial in order to tailor and monitor appropriate treatment and determine prognosis. Cervical Duplex Ultrasound (CDU) has evolved since many years as an excellent screening tool for the evaluation of extracranial vasculature. CDU has the advantages of a low cost, easily applicable, bed side examination with high temporal and spatial resolution and without exposing the patients to any significant complications. It represents an easily repeatable test that can be performed in the emergency room as a first-line examination of cervical artery pathology. CDU provides well validated estimates of the type of the atherosclerotic plaque, the degree of stenosis, as well as structural and hemodynamic information directly about extracranial vessels (e.g., subclavian steal syndrome) and indirectly about intracranial circulation. CDU may also aid the diagnosis of non-atherosclerotic lesions of vessel walls including dissections, arteritis, carotid-jugular fistulas and fibromuscular dysplasias. The present narrative review outlines all potential applications of CDU in acute stroke management and also highlights its potential therapeutic implications.

A comparison of carotid doppler ultrasonography and capnography in evaluating the efficacy of CPR.

INTRODUCTION AND PURPOSE: The end-tidal carbon dioxide (ETCO2) measurement is accepted as the gold standard method for assessing cardiopulmonary resuscitation (CPR) efficacy. In recent studies, the use of Carotid Doppler Ultrasonography has become widespread in showing CPR efficacy. In the present study, the carotid blood flow measurement was compared with ETCO2 measurement and an evaluation was made of whether this method could be used as an alternative method to capnography in the assessment of CPR efficacy. MATERIAL AND METHOD: This study was conducted on patients who presented at the Emergency Department (ED) with non-traumatic arrest or began to suffer from arrest during emergency service follow-up. The main carotid artery peak systolic velocity (PSV), end diastolic velocity (EDV) and time-dependent mean flow velocity (MNV), and ETCO2 values were measured and recorded after the 100th chest pressure of the CPR cycle and the results were statistically analyzed. RESULTS: The mean age of the patients was 54.5±12.3years and 65.6% of the patients were male. The mean values of patients measured from the carotid artery during the CPR were PSV 67.1±17.3, EDV 16.3±4.5, MNV 25.5±8.1 and ETCO2 22.2±8.1. A significant difference was found between in-hospital and out-of-hospital arrests in terms of patient outcome (return of spontaneous circulation (ROSC) and death) (p<0.05). The mean ETCO2 values of those who died were found to be lower than those of the ROSC group (p<0.05). Although there was a positive and low-level of correlation between the ETCO2 values and PSV values, and a positive and very low-level of correlation between the EDV and MNV values of all patients, these correlations were not statistically significant. (p>0.05). CONCLUSION: A low correlation was found between the PSV and ETCO2 values. With effective CPR, the results close to carotid blood flow in normal healthy individuals were obtained. However, the study showed that carotid blood flow measurement results during CPR were not as valuable as ETCO2 in demonstrating CPR efficacy.

Accuracy of Carotid Duplex Criteria in Diagnosis of Significant Carotid Stenosis in Asian Patients.

BACKGROUND: Extracranial carotid stenosis can be diagnosed by velocity criteria of carotid duplex. Whether they are accurately applied to define severity of internal carotid artery (ICA) stenosis in Asian patients needs to be proved. The purpose of this study was to evaluate the accuracy of 2 carotid duplex velocity criteria in defining significant carotid stenosis. METHODS: Carotid duplex studies and magnetic resonance angiography were reviewed. Criteria 1 was recommended by the Society of Radiologists in Ultrasound; moderate stenosis (50%-69%): peak systolic velocity (PSV) 125-230 cm/s, diastolic velocity (DV) 40-100 cm/s; severe stenosis (>70%): PSV greater than 230 cm/s, DV greater than 100 cm/s. Criteria 2 used PSV greater than 140 cm/s, DV less than 110 cm/s to define moderate stenosis (50%-75%) and PSV greater than 140 cm/s, DV greater than 110 cm/s for severe stenosis (76%-95%). RESULTS: A total of 854 ICA segments were reviewed. There was moderate stenosis in 72 ICAs, severe stenosis in 50 ICAs, and occlusion in 78 ICAs. Criteria 2 had slightly lower sensitivity, whereas higher specificity and accuracy than criteria 1 were observed in detecting moderate stenosis (criteria 1: sensitivity 95%, specificity 83%, accuracy 84%; criteria 2: sensitivity 92%, specificity 92%, and accuracy 92%). However, in detection of severe ICA stenosis, no significant difference in sensitivity, specificity, and accuracy was found (criteria 1: sensitivity 82%, specificity 99.57%, accuracy 98%; criteria 2: sensitivity 86%, specificity 99.68%, and accuracy 99%). CONCLUSIONS: In the subgroup of moderate stenosis, the criteria using ICA PSV greater than 140 cm/s had higher specificity and accuracy than the criteria using ICA PSV 125-230 cm/s. However, there was no significant difference in detection of severe stenosis or occlusion of ICA.

Exploring the best predictors of fluid responsiveness in patients with septic shock.

OBJECTIVE: To evaluate respiratory variations in carotid and brachial peak velocity and other hemodynamic parameters to predict responsiveness to fluid challenge. METHODS: A prospective observational study was performed on mechanically ventilated patients with septic shock. Outcomes included the measurements of central venous pressure, intrathoracic blood volume index, stroke volume variation (SVV), pleth variability index(PVI), and ultrasound assessments of respiratory variations in inferior vena cava diameter (ΔIVC), carotid Doppler peak velocity (ΔCDPV), and brachial artery peak velocity (ΔVpeak brach). RESULTS: All patients received 200 mL normal saline challenge. There were 27 responders and 22 non-responders. Responders had higher SVV, PVI, ΔIVC, ΔCDPV, and ΔVpeak brach measurements. In addition, all these measurements had statistically significant linear correlations with changes in cardiac index (CI).When responders were defined by ΔCI≥10%, receiver operating characteristics (ROC) curve analysis showed that fluid responsiveness could be predicted:11.5% optimal cut-off 1evels of SVV with sensitivity of 75% and specificity of 85%, 15.5% optimal cut-off 1evels of PVI with sensitivity of 65% and specificity of 80%, 20.5% optimal cut-off 1evels of ΔIVC with sensitivity of 67% and specificity of 77%, 13% optimal cut-off 1evels of ΔCDPV with sensitivity of 78%% and specificity of 90%, 11.7% optimal cut-off 1evels of ΔVpeak brach with sensitivity of 70% and specificity of 80%. CONCLUSION: Ultrasound assessment of ΔIVC and ΔVpeak brach, especially ΔCDPV, could predict fluid responsiveness and might be recommended as a continuous and noninvasive method to monitor functional hemodynamic parameter in mechanically ventilated patients with septic shock.

Characteristics of Cerebral Hemodynamics in Patients with Ischemic Leukoaraiosis and New Ultrasound Indices of Ischemic Leukoaraiosis.

OBJECTIVE: The diagnosis of ischemic leukoaraiosis (ILA) is based on head magnetic resonance imaging (MRI) and exclusion of other causes of white matter hyperintensities (WMHs). Recent studies have shown increased arterial stiffness and diminished carotid flow in ILA patients. So far, there are very little data on intracerebral hemodynamic parameters in ILA. Due to the specific structure of the intracranial arteries, our aim was to investigate intracerebral hemodynamic parameters in ILA patients and, possibly, to find a reliable ultrasound index of combined intra- and extracranial cerebral arteries. METHODS: We compared different hemodynamic parameters in the middle cerebral artery (MCA) and local carotid stiffness parameters in 53 ILA patients to 40 gender and risk factor-matched controls with normal head MRI. The ILA diagnosis was based on head MRI and exclusion of other causes of WMH. In addition, we introduced new ischemic leukoariosis indices (ILAi) that are ratios of carotid stiffness parameters and MCA mean blood flow velocity. The diagnostic significance of ILAi for the prediction of ILA was analyzed. RESULTS: We found significantly lower diastolic, systolic, and mean MCA blood flow velocities and increased carotid stiffness in the ILA group (P ≤ .05). All ILAi significantly differed between the groups (P < .05), were significantly associated with ILA (P < .01), and were sensitive and specific for predicting ILA (P < .05). CONCLUSION: MCA blood flow velocities in ILA patients are lower compared to risk factor-matched controls. A combination of lower velocities and increased carotid stiffness represented as ILAi could have a potential diagnostic value for ILA.