Why Does Vascular Access Dysfunction Occur despite Brachial Artery Blood Flow Being Higher than Preset Blood Flow?

Background: In recent years, many reports have investigated the usefulness of brachial artery blood flow (BAF) measured by ultrasonography as an evaluation index for the vascular access (VA) stenosis of hemodialysis patients. However, the mechanism of VA dysfunction, despite BAF being higher than the preset blood flow, has not been clarified to date. Methods: The relationship between actual blood-removal flow and recirculation rate with decreasing VA flow was examined using a VA flow path model and pure water as a model fluid. The blood-flow rate was set at 180 mL/min, and the set VA flow rate was lowered stepwise from 350 to 50 mL/min. VA flow rate, blood-removal flow rate, and flow waveform measured between two needle-puncture sites were recorded, and then the actual blood-removal flow rate and recirculation rate were calculated. Results: Recirculation was observed at a VA flow rate < 300 mL/min. The recirculation was due to the VA flow rate, which was transiently reduced to the level below the blood-removal flow rate, resulting in backflow. In contrast, no decrease in the actual blood-removal flow rate was observed. Conclusion: It is suggested that the mechanism of the VA dysfunction, despite the BAF being higher than the preset blood-flow rate, was due to the diastolic BAF being lower than the blood-removal flow rate.

An Exploratory Study on the Relationship between Brachial Arterial Blood Flow and Cardiac Output

Background. We have obtained prospective clinical outcomes using the brachial artery largely, such as Korotkoff sound and vasomotor function measurement by ultrasound guidance to predict the prognosis of cardiovascular diseases. Very few reports on the quantitative measurement of the relationship between the brachial artery blood flow and cardiac output have been reported. Purpose. (1) To investigate whether the quantitative relationship between the brachial artery blood flow and cardiac output existed. (2) To provide a theoretical basis for taking advantage of artificial intelligence (AI) using Korotkoff sound analogously as far as possible to predict the cardiac output. Methods. A total of 586 patients who underwent cardiac color ultrasound in our center from 2021.3 to 2021.7 were included for analyses. The vascular parameters of the right upper limb brachial artery (such as the Diameter, Area, Blood Velocity, and Flow) were measured immediately after the cardiac color ultrasound, and some basic clinical parameters (Age, Sex, BMI, and Disease) were recorded subsequently. Ultimately, the Mann–Whitney and independent sample T-test were used to analyze the data. Results. (1) The mean Rate of the brachial arterial blood flow to cardiac output was 1.23%, and the mean 95% CI was (1.18%, 1.29%), indicating that the value was mainly concentrated in the current value interval. The indicator demonstrates that there is no significant difference currently among the patients with hypertension, coronary heart disease, and cardiac dysfunction. (2) The brachial artery wall diameter (Dist) is significantly thicker in patients with coronary heart disease and hypertension compared to patients with other cardiovascular diseases. (3) Cardiac output augments remarkably in patients with hypertension. Conclusion. Our study suggests that the Rate (brachial artery blood flow/cardiac output) is a constant of 1.23% approximately. It provides a theoretical basis for the subsequent application of the artificial intelligence (AI) method to predict heart function using Korotkoff sound, cope with large computational amounts, and improve computational speed. It is also indirectly proved that hypertension can lead to a change in peripheral vascular hyperplasia and increase cardiac output.

Correlation between Parturients’ Uterine Artery Blood Flow Spectra in the First and Second Trimesters of Pregnancy and Fetal Growth Restriction

Objective. To explore the correlation between parturients’ uterine artery blood flow spectra in the first and second trimesters of pregnancy and fetal growth restriction (FGR). Methods. The data of parturients treated in our hospital from February 2018 to February 2020 were retrospectively analyzed, 50 parturients with FGR were selected as the FGR group, and other 50 healthy cases were selected as the control group. In the first trimester (11-12 weeks of gestation) and the second trimester of pregnancy (13–24 weeks of gestation), the parturients of the two groups accepted the color Doppler ultrasonography (CDS), their hemodynamics indicators of uterine artery were recorded, and the correlation between their uterine artery blood flow spectra in the two periods and FGR was analyzed with the Receiver Operating Characteristic (ROC) curve. Results. No statistical differences in the parturients’ general information including age, gestational weeks, gravidity, and parity between the two groups were observed ( P > 0.05); the newborn’s body weight, Apgar scores, number of preterm infants, and the number of infants transferring to the neonatal intensive care unit (NICU) were significantly different between the two groups ( P < 0.05); in the first and second trimesters of pregnancy, the uterine artery pulsatility index (UtA-PI), uterine artery resistance index (UtA-RI), maximal systolic flow velocity, and systolic/diastolic (UtA-S/D) ratio were significantly higher in the FGR group than in the control group ( P < 0.05), and the time-averaged maximal velocity (TAMX) was significantly lower in the FGR group than in the control group ( P < 0.001); in early pregnancy, the incidence of early diastolic notch at bilateral uterine arteries between the two groups was not significantly different ( P > 0.05), and the unilateral and total incidence in the first trimester as well as the unilateral, bilateral, and total incidence in the second trimester were significantly higher in the FGR group than in the control group ( P < 0.05); in the first trimester, the sensitivity of detecting FGR with a uterine artery blood flow spectrum was 0.820, AUC (95% CI) = 0.840 (0.757–0.923), and in the second trimester, it was 0.860, AUC (95% CI) = 0.900 (0.832–0.968). Conclusion. There is a correlation between uterine artery blood flow spectra in the first and second trimesters of pregnancy and FGR, and the sensitivity of spectrum in the first trimester is higher than that in the second trimester, presenting a better clinical application value.

Acceleration time to Ejection time ratio in fetal pulmonary artery system can predict neonatal respiratory disorders in gestational diabetic mellitus women

BACKGROUND: Few researches studied fetal pulmonary pulse wave doppler and the clinical end point disorders in gestational diabetic mellitus (GDM) cohort. OBJECTIVE: To investigate fetal pulmonary artery acceleration time to ejection time ratio (PATET) in the prediction of neonatal respiratory disorders (NRD). METHODS: 238 pregnant women diagnosed with GDM who attended our hospital between February 2018 and March 2020 were retrospectively included. Fetal pulmonary artery Doppler wave measurements were recorded, including main, left and right pulmonary artery blood flow, and left and right peripheral pulmonary artery blood flow. Acceleration time (At)/ejection time (Et) were calculated. RESULTS: 183 GDM pregnant women and neonates were divided into NRD(+)(n = 42) and NRD(–) group (n = 141). 16 cases were neonatal pneumonia (NP) within 28 days after birth in NRD(+) group. The area under curve (AUC) of left peripheral pulmonary artery acceleration time to ejection time (LPPATET) was 0.967 (95% CI: 0.927∼1.000, P < 0.001) and the AUC of right peripheral pulmonary artery acceleration time to ejection time (RPPATET) was 0.967 (95% CI: 0.927∼1.000, P < 0.001), indicating that LPPATET and RPPATET are both predictors for NRD. The results of interobserver variabilty and intraobserver variability showed a good consistency. CONCLUSIONS: The At/Et of fetal peripheral pulmonary artery (PPA) in GDM women may be predictors for NRD, and the indicator can provide assistance in clinical management of diabetes pregnant patients.

Evaluation of radial and ulnar artery blood flow after radial artery decannulation using colour Doppler ultrasound

Background There is a lack of reports in the literature regarding changes in radial artery blood flow after decannulation. The objective of this study was to investigate changes in radial and ulnar artery blood flow after radial artery decannulation using Doppler ultrasound and to explore the factors that influence radial artery blood flow recovery. Methods In current observational study, we used colour Doppler ultrasound to measure the cross-sectional area of the radial (SR) and ulnar artery (SU) and peak systolic velocity of the radial (PSVR) and ulnar artery (PSVU) for both hands at four time points in patients with radial artery cannulation: pre-cannulation (T0), 30 min after decannulation (T1), 24 h after decannulation (T2), and 7 days after decannulation (T3). Repeated measures analysis of variance and logistic regression analysis were performed to analyse the data. Results Overall, 120 patients were included in the present study. We obtained the following results on the side ipsilateral to the cannulation: compared with T0, the ratio of PSVU/PSVR increased significantly at T1 and T2 (p < 0.01); compared with T1, the ratio of PSVU/PSVR decreased significantly at T2 and T3 (p < 0.01); compared with T2, the ratio of PSVU/PSVR decreased significantly at T3 (p < 0.01). Female sex (OR, 2.76; 95% CI, 1.01–7.57; p = 0.048) and local hematoma (OR 3.04 [1.12–8.25]; p = 0.029) were factors that were significantly associated with the recovery of radial artery blood flow 7 days after decannulation. Conclusions There was a compensatory increase in blood flow in the ulnar artery after ipsilateral radial artery decannulation. Female sex and local hematoma formation are factors that may affect the recovery of radial artery blood flow 7 days after catheter removal.