جستجوی مقالات مرتبط با کلیدواژه « blood flow velocity » در نشریات گروه « پزشکی »

Beta-thalassemia intermedia (BTI) is a type of hemoglobinopathy with an increased risk of cerebrovascular accidents, and transcranial cerebral Doppler ultrasonography (TCD) through determining the mean cerebral blood flow velocity (CBFV) can serve to predict the risk of a developing stroke. This study aims to compare patients with beta-thalassemia intermedia and healthy individuals in terms of the cerebral blood flow velocity.

This research was a case control study on 35 BTI patients and 25 healthy subjects. The patients were categorized into three age groups including 7-10, 11-15 and 16-20 years old. The mean CBFVs were compared between the two groups. The factors of age, gender, serum ferritin level, hemoglobin level, spleen size, thrombocytosis, and thalassemia genotypes were evaluated for their effects on CBFVs.

Mean CBFVs were significantly higher in all the intracranial arteries of BTI patients compared to normal subjects (p-value < 0.05). The hemoglobin levels showed a negative correlation between the left and right vertebral arteries of BTI patients in terms of blood flow velocity (p-value < 0.05). The mean CBFVs in the left vertebral and basilar arteries were negatively correlated to age in BTI. There was no correlation among ferritin level, thrombocytosis, splenomegaly, splenectomy, XmnI polymorphism, and cerebral blood flow velocity in the BTI patients group (p-value > 0.05).

This study showed that cerebral blood flow velocities of BTI patients were higher than normal control group. In addition, CBFVs were not affected by factors such as gender, serum ferritin, platelet count, size of spleen and XmnI genotype, however, there was negative correlation between age and hemoglobin level with CBFVs.

Despite the tendency to important infectious and mechanical complications, central venous catheters have become a common means of vascular access worldwide for patients requiring hemodialysis. In some studies, the use of fibrinolytic drugs is effective in the treatment of catheter function problems. In this study, the effects of Alteplase (a fibrinolytic drug) on catheter function was investigated.

This study was performed on 100 dialysis patients in the dialysis ward of Imam Reza Hospital in Kermanshah (Iran) who had a catheter dysfunction. After confirmation by the nephrologist, in case of catheter dysfunction and failure to resolve it with the usual methods, one milligram of Alteplase with normal saline was added to each lumen of the catheter and left in place for one hour. After aspirating the lacquered solution, the rate of blood outflow was assessed by aspiration, and catheter function was evaluated.

The mean age was 60.31 +- 11.67 years. 52 patients were male and 48 patients were female. In terms of catheter implantation time, 20 patients were less than 3 months, 12 patients were between 3 to 6 months and 68 patients were more than 6 months. The duration of proper catheter function after injection was less than 3 months in 11 patients, between 3 to 6 months in 31 patients, and more than 6 months in 58 patients. Only 6 out of 100 cases received 2 mg and others received 1 mg of the drug. 25 patients had the insufficient effect of the drug on catheter function in terms of blood flow velocity, and in 75 patients this effect was good. Only 8 patients had inoperable lock catheters. Out of 100 patients studied, 7 had temporary catheters and 93 had permanent catheters.

Alteplase is safe and effective on catheter function in hemodialysis patients.

Fatigue is one of the outcomes of reduced dialysis adequacy (DA) in patients undergoing hemodialysis (HD). Accordingly, increased blood flow velocity (BFV) can be one of the strategies to enhance DA and reduce fatigue. This study aimed to determine the effect of increased BFV on fatigue in HD patients. This two-group randomized clinical trial was conducted on 74 HD patients attending 17-Shahrivar Hospital and Shafa Dialysis Center, Mashhad, Iran, during 2018. The intervention group was subjected to 25 and 50 rounds, which were added to the mean value calculated for dialysis machine velocity. Considering the control group, the rounds of the machine were set as those mean of the first two sessions. Fatigue was measured using the standardized Multidimensional Fatigue Inventory. The blood urea nitrogen (BUN) level and DA were analyzed after the 1st, 8th, and 14th sessions. The data were analyzed in SPSS software (version 16) through independent t-test, repeated measures analysis of variance (ANOVA), Mann-Whitney U test, and Chi-square test. The mean ages of the control and intervention groups were 57.16±13.81 and 55.86±13.56 years, respectively. The results of repeated measures ANOVA showed that fatigue in the intervention group had significantly dropped during HD sessions, compared to the control group. Moreover, these patients obtained better DA (P˂0.001). Implications for Practice: Increased BFV of the dialysis machine leads to improved DA, BUN removal, and reduced fatigue in HD patients, which can be recommended to nurses as an effective strategy.

Ischemic stroke as the major cause of mortality and morbidity worldwide has different risk factors. One of its modifiable risk factors is opium addiction whose role is not clear yet. This study aimed at assessing the hemodynamic parameters in ischemic stroke patients addicted to opium using transcranial Doppler (TCD) ultrasonography and comparing them with non-addicted patients. This comparative cross-sectional study was conducted in an academic hospital in the north of Iran in 2016. All the patients diagnosed as ischemic stroke underwent cerebrovascular ultrasound in the first 4 days of symptoms onset. Frequency of hemodynamic abnormalities confirmed by pulsatility index (PI) and mean flow velocity (MFV) were determined and compared between the two groups. The data were analyzed by chi-square test, t-test, and multiple logistic regression models using SPSS software. A total of 353 patients with ischemic stroke (92 addicted and 261 non-addicted patients) were enrolled in the study. Univariate analysis indicated that the PI and MFV differences were statistically significant between two groups of addicted and non-addicted patients (P = 0.0001). By multivariate logistic regression model, the age [odds ratio (OR) = 1.143], diabetes mellitus (DM) (OR = 3.875), hypertension (HTN) (OR = 2.557), and opium usage (OR = 9.615) had influence on PI and only opium usage (OR = 3.246) had influence on MFV. Opium usage affects the cerebral hemodynamic parameters and increases the chance of having abnormal PI as ten-fold and abnormal MFV as three-fold.

The torsional parameters of the left ventricle (LV) are sensitive indicators of the cardiac performance. The torsion/twist of the LV is the wringing motion of the heart around its long axis created by oppositely directed apical and basal rotations and is determined by contracting myofibers in the LV wall which are arranged in opposite directions between the subendocardial and subepicardial layers. This motion is essential for regulating the LV systolic and diastolic functions.. Recent advances in echocardiography techniques have allowed for quantification of LV mechanics. The aim of the present study was to compare various LV twisting and untwisting parameters in healthy human subjects determined by velocity vector imaging (VVI) and tissue Doppler imaging (TDI) at rest..Patients and All volunteers (47 healthy subjects in two groups: 24 subjects in VVI group and 23 subjects in TDI group) underwent complete echocardiographic study, and LV torsional parameters were assessed by VVI or TDI methods. In addition, LV torsion and LV twisting/untwisting rate profiles were calculated throughout cardiac cycle.. Twist degree was significantly lower in the VVI group than in the TDI group (P = 0.008, r = 0.56). LV torsion was lower in the VVI group but was not significant. (P = 0.13, r = 0.38). Twisting rate (P = 0.004, r = 0.66) and untwisting rate (P = 0.0001, r = 0.61) were lower in the VVI group, but when timing of untwisting rate was normalized by systolic duration, there was no significant difference between the two groups (P = 0.41, r = 0.59). Similarly, when peak untwisting rate was normalized by LV length, there was a significant decline in normalized peak untwisting rate in the VVI group (P = 0.004, r = 0.62), but not in peak twisting rate normalized by LV length (P = 0.12, r = 0.42). Peak untwisting rate normalized by LV torsion was not statistically different between the two groups (P = 0.05, r = 0.53).. Results suggest that these methods cannot be interchanged, and VVI showed significantly lower LV peak twist, peak twisting rate and peak untwisting rate. However, when LV twist and LV twisting rates were normalized to LV length, values were comparable for both imaging techniques.