[Effects of compression stockings on cutaneous microcirculation].
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Adult↗
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Results for “Laser-Doppler Flowmetry”
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Laser Doppler skin perfusion pressure in normal and vascular subjects with rest pain: an universal measurement?
Laser-Doppler (LDF) skin perfusion pressure was measured and compared with Doppler ankle pressure measurements in 40 normal subjects and 20 patients with rest pain and ankle/foot Doppler pressure lower than 70 mmHg. Six different, commercially available LDF instruments were used. To obtain perfusion pressure a standard blood pressure cuff was used measuring the pressure at which the skin flux reading reached the biological zero level when inflating the cuff (P1) and the pressure at which the LDF tracing reappeared after deflating the cuff from sovrasistolic pressure level (P2). Perfusion pressure (PP) was considered to be the average [P1 + P2]/2. No differences in PP amongst the 6 instruments both in normal and vascular subjects were observed. These results indicate that PP is an universal LDF measurement which can be easily obtained with different LDF instruments.
Ankle↗
[Cutaneous microcirculation in systemic sclerosis. Morpho-functional research using capillaroscopy and laser-Doppler].
Our previous researches proved that, in patients affected by Raynaud disease, microcirculatory alterations were greater in those cases in which the small vessels showed evocative appearances of a sclerodermatous connectivopathy. In this study we evaluated cutaneous microvasculature in 18 patients suffering from clear systemic sclerosis, compared with a group of 16 subjects affected by primitive Raynaud disease and a group of healthy subjects. We used videocapillaroscopy and laser-Doppler fluxmetry for morphological and functional study respectively. In patients affected by systemic sclerosis the rest flow was clearly reduced and morphological pattern of cutaneous small vessels deranged. The response to ischemic test allowed us to subdivide the skin-bounds in two subgroups: "no responders" 8 subjects (44%), in which reactive hyperaemia was completely absent, "responders" 10 patients (56%) in which the hyperaemia was completely overlapped with that of the two other groups, but with longer reaction times. In skinbounds the capillaroscopic pattern was clearly severe in comparison with other two groups (18.8 +/- 5.7 vs 5.7 +/- 2.3 and 3.6 +/- 1). Thus, in advanced stage of the pathology, is microangiopathy (in its tromboischemic and inflammatory aspects) that plays a very important role in the development of organ damage. Therefore, all those clinical and instrumental tests which may allow a differential early diagnosis between a primitive and a secondary Raynaud phenomenon be done, for its prognostic value in connection with the appearance of systemic sclerosis.
Adult↗
Cardiovascular and cerebrovascular effects of the applied Valsalva manoeuvre in anaesthetized neurosurgical patients.
We examined the effects of Valsalva's manoeuvre and its four phase on heart rate, central venous pressure (CVP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), and laser Doppler cerebellar cortical blood flow (CBF). Brief Valsalva manoeuvres increased CVP and markedly decreased MAP. Cerebral perfusion pressure significantly (P < or = 0.01, Dunnett's test) decreased during phases 2 and 3 of the Valsalva manoeuvre. Cortical blood flow closely paralleled CPP; CBF decreased to 59% of control during phase 2 and to 57% of control during phase 3 of the Valsalva manoeuvre. The MAP, CPP, and CBF all returned to baseline levels during phase 4 (the overshoot phase) of the Valsalva manoeuvre, and were not significantly greater than control. No autoregulatory change in cerebrovascular resistance occurred throughout the Valsalva manoeuvre. These results suggest that brief Valsalva manoeuvres, as employed during neurosurgical procedures, mainly confirm venous haemostasis, but must be used cautiously due to the marked haemodynamic changes.
Aged↗
The use of Doppler velocimetry of the umbilical artery before 24 weeks' gestation to screen for high-risk pregnancies.
OBJECTIVE: To describe the prevalence and natural history of absent end-diastolic velocities (AEDV) in the umbilical artery of the fetus between 16 and 24 weeks' gestation, and to evaluate its role as a screening test. DESIGN: Population-based descriptive study. SETTING: Tygerberg Hospital, Tygerberg, South Africa. The hospital serves a population from the lower socio-economic bracket. SUBJECTS: Doppler velocimetry was performed at routine ultrasound examinations for confirmation of gestational age in 496 women. MAIN OUTCOME MEASURES: The occurrence of perinatal death, small-for-gestational-age (SGA) babies and proteinuric hypertension. RESULTS: Forty-four (8.9%) patients had AEDVs at the first examination, but AEDV persisted in only 1. In this case, severe proteinuric hypertension developed unexpectedly at 29 weeks' gestation and the fetus needed delivery because of persistent late decelerations of the fetal heart rate pattern. There was a significant association between the group with AEDV at first examination and the development of proteinuric hypertension (P < 0.05), but no association with SGA babies. The association with proteinuric hypertension was too weak to be of clinical use. CONCLUSION: Doppler velocimetry of the umbilical artery, performed along with routine ultrasound examination to confirm gestational age, is not of use as a screening test for identifying high-risk pregnancies.
Blood Flow Velocity↗
Retinal circulatory abnormalities in type 1 diabetes.
PURPOSE: To quantify retinal circulatory abnormalities in patients with type 1 diabetes; to 1 diabetes; to compare blood speed and blood flow in major temporal retinal arteries as well as total retinal arterial cross-section measured in patients to that measured in controls without diabetes; to determine which factors are related to the measured abnormalities within the patient group. METHODS: The laser Doppler technique and monochromatic fundus photography were used to measure retinal circulatory parameters in 39 patients with type 1 diabetes with duration of diabetes between 7 and 20 years and 13 age-matched controls without diabetes. Blood pressure, intraocular pressure, and heart rate were measured in all subjects. Glycosylated hemoglobin was measured in the patients. Retinopathy was assessed using standardized color fundus photography and fluorescein angiography. RESULTS: Total retinal arterial cross-section was, on average, 17% higher (P = 0.007) in the patients than in the controls, and it increased with increasing duration of diabetes (P = 0.006). Arterial blood speed was, on average, 33% lower (P = 0.0001) in the patients than in the controls, and it decreased with increasing duration of diabetes (P = 0.03). CONCLUSIONS: The retinal circulation of patients with type 1 diabetes with no retinopathy or background retinopathy is characterized by dilated major arteries with reduced blood speeds. Dilation of the larger retinal arteries, with the accompanying decrease in vascular resistance to flow in those vessels, appears to counteract an increase in resistance to flow at the level of the smaller retinal vessels.
Adult↗
[Colored biomicrospheres for studies of cochlear microcirculation].
For many years in our laboratory, toads red blood cells have been used as biomicrospheres for study of cochlear microcirculation. In the present experiments the cochlear blood flows (CBF) was twice determined in the same animal by using colored biomicrospheres. The red blood cells were stained separately with eosin and azure blue. The biomicrospheres of two different colors were injected intracardially in the same guinea pig at two different times with an interval of 4 min. The CBF were detected by using a laser Doppler system simultaneously. The finding showed that color of red and blue biomicrospheres were contrast sharply, they were all distinguished easily from the surrounding tissue. The adequate number of microspheres injected each time was 9 x 10(6)/ml. The results of CBF were not different between the first and second injection.
Animals↗
[The effect of superior cervical sympathetic ganglionectomy on cochlear blood flow in guinea pigs].
The effect of superior cervical sympathetic ganglionectomy on cochlear blood flow (CoBF) was observed in 21 guinea pigs. The CoBF was measured with Laser Doppler Flowmeter. The systemic blood pressure (BP) was simultaneously recorded. The elevation of BP as well as the increase in CoBF following ganglionectomy were not statistically significant; the change in CoBF was somewhat consistent with the variation of BP. The results imply that there is no significant effect of superior cervical sympathetic ganglionectomy on CoBF of guinea pigs.
Animals↗
Reduced fingertip blood flow and peripheral dysautonomia in leprosy patients in Iranian Azerbaijan and in Maharashtra, India.
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Autonomic Nervous System Diseases↗
The relationship between subjective vasospastic complaints and finger blood flow measurements in Raynaud's phenomenon.
BACKGROUND: Objective circulatory tests in patients with Raynaud's phenomenon have only rarely been related to subjective complaints. METHODS: In 55 Raynaud patients the correlation between daily self-recorded frequency, duration and severity of vasospastic attacks and the measurement of finger skin blood flow during local cooling was investigated. RESULTS: No significant correlations were found between complaints as registered in the diaries and finger skin temperature and laser Doppler flux before, during and after a standardized local cooling procedure. CONCLUSION: Finger skin blood flow measurements do not necessarily reflect digital vasospasm in daily life. Besides studies on the diagnostic value and reproducibility of skin blood flow measurements in Raynaud's phenomenon, the relationship of test results to subjective complaints should be established.
Activities of Daily Living↗
Effect of preoperative irradiation on wound healing after bronchial anastomosis in mongrel dogs.
To determine the endurable radiation dose before bronchial anastomosis, the bronchial circulation of mongrel dogs was assessed after bronchoplastic surgery conducted after various single doses of radiation. Plastic surgery of the right main bronchus was carried out 1 week after cobalt 60 irradiation to the right hilar region. Bronchial blood flow was measured with laser Doppler velocimetry 7, 14, and 30 days after operation. Animals were killed 30 days after operation and the region of the bronchial anastomosis was examined histologically. The animals were divided into five groups: group A (control group without irradiation), group B (8 Gy irradiation), group C (16 Gy), group D (19 Gy), and group E (24 Gy). Wound healing of the anastomosed bronchus was excellent in groups A and B. In group A, bronchial blood flow did not drop below 80% of the preoperative level throughout the postoperative observation period. In group B, bronchial blood flow on day 7 after operation was only 65% of the preoperative level, but blood flow had returned to the preoperative level by day 30. In groups C, D, and E, bronchial blood flow was less than 60% of the preoperative level on day 30. There was a high prevalence of radiation-induced morbidity in the region of anastomosis in groups C, D, and E. Postoperative recovery of bronchial blood flow and wound healing of the anastomosed bronchus were thus delayed in dogs that had received high doses of radiation before operation. We conclude that the safe dose of preoperative radiation in clinically used fractionation is 36 Gy or less (corresponding to a single dose of 16 Gy or less in dogs).
Anastomosis, Surgical↗
[Warm ischemia and reperfusion injury in the regenerating rat liver].
The effect of warm ischemia and reperfusion injury in the regenerating rat liver after portal vein branch ligation (PBL) was examined by monitoring hepatic high energy phosphorous metabolism using in vivo Phosphorus-31 Magnetic Resonance Spectroscopy (31P-MRS). On 14 days after 70% occlusion of the portal vein, energy metabolism of non-occluded lobe of the liver was evaluated by measuring the ratio of beta-ATP to Pi obtained using 31P-MRS. During 30min-ischemia, beta-ATP/Pi dropped down similarly below the limit of observation in both of control and regenerating liver. However, after reperfusion, in the regenerating liver, the earlier and better recovery of beta-ATP/Pi was observed compared with the control. In the any examination of m-GOT, GPT, increase in enzyme level was apparently restrained in the PBL group. On the pathological examination, centrilobular necrosis and hepatocyte degeneration were remarkable in the normal liver, while in the regenerating liver, these changes were slight. In conclusion, these results suggest that reperfusion injury observed in the regenerating liver seems to be reduced compared with that in the normal liver. Functional and structural changes in the regenerating liver could be claimed as a course of this observation. However, to understand the mechanism, further study will be needed both in morphological and biochemical aspect.
Animals↗
Tooth discoloration and resolution following a luxation injury: significance of blood pigment in dentin to laser Doppler flowmetry readings.
Discoloration of teeth is common sequel of dental trauma and is often taken as a sign of irreversible pulpal degeneration, particularly if the crown becomes gray or blue-gray in appearance. If a viable blood supply remains or revascularization occurs following trauma to teeth, removal of blood pigments by normal biologic processes can occur. The assessment of blood flow with laser Doppler flowmetry is an additional diagnostic aid following dental injuries. This technology has been used to monitor the clinical progress of two central incisors that had been palatally luxated in a sporting accident. Color changes were observed and were correlated with symptomatic and radiographic evaluation, sensibility tests, and laser Doppler readings. The results of these examinations indicated that the blood pigment within a discolored tooth crown interfered with laser light transmission. The limitation of this new technology in the assessment of teeth discolored following trauma is significant. Visual radiographic and symptomatic assessment remain as the principal diagnostic criteria at the present time.
Adolescent↗
Doppler velocimetry study of maternal hemodynamics and fetal vascular pattern in a case of chronic hypertension with superimposed severe preeclampsia and impending fetal death.
A case is presented of chronic hypertension with superimposed severe preeclampsia; absence of end-diastolic velocity in the umbilical artery had been noted at gestational age of 20 weeks. Because the fetus was previable, the mother was treated with pharmacotherapy according to the maternal hemodynamics; uteroplacental circulation and fetal vascular blood flow were monitored by Doppler velocimetry. Deterioration of the fetal condition occurred during crossover of maternal hemodynamics from a low-resistance to a high-resistance state. Serial Doppler velocimetry studies done within 40 minutes of fetal death are described. There were two types of absent end-diastolic velocity in the umbilical artery, and the pathophysiology and clinical management may be quite a different in these two situations.
Adult↗
Effects of skin blood flow and temperature on bioelectric impedance after exercise.
To examine the effects of increased skin blood flow (BFsk) and skin temperature (Tsk) on bioelectric impedance (BIA), 30 young males participated as subjects. All subjects underwent the following measurements: 1) BFsk and Tsk for the chest, biceps, thigh, and calf; 2) body composition using the BIA prediction equations and underwater weighting (UW); and 3) triceps skinfold (SFtri) thickness. After the baseline studies (M1) the subjects exercised for 30 min at approximately 83% of maximal heart rate. The above measurements were repeated immediately after exercise (M2), and at 1-h recovery from exercise (M3). Repeated measures ANOVA showed that mean Tsk and BFsk, and for the four measured sites were significantly increased from M1 to M2 (P < 0.05) and decreased from M2 to M3 (P < 0.05). These changes did not affect BIA measurement for resistance (R) and reactance between M1 and M2 (P > 0.05), and between M2 and M3 (P > 0.05). With regression analysis the following independent variables were identified as strong contributing factors for predicting fat-free mass (FFM): 1) SFtri and total body water for M1 and M3; and 2) WT, SFtri, and Tsk of the chest for M2. Two FFM equations have little multicolinearity (M1 and M2), e.g., they have low root mean square errors (< or = 2.6 kg), very high values for R2 (> or = 0.94), and relatively low values for coefficient of variations (< or = 5.65%). Differences (P < 0.05) were observed between the UW method and the Lukasi equation for estimating FFM for M1 and M3, but not for M2.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Microcirculatory changes in mitral prolapse as an expression of a systemic change in the connective tissue].
Many authors hypothesize that mitral valve prolapse (MVP) can be, in most cases, only a clinical sign of a primitive and systemic disorder of the connective tissue, like in Marfan Syndrome (MS). In our previous works we supported the presence of morphological and functional alterations of the microcirculation in patients affected by MS. In order to characterize a possible common denominator between these pathologies we have studied the cutaneous microcirculation in a group of patients affected by MVP, divided into 2 groups: anatomic MVP (MVP) and MVP syndrome (MVPS). The morphologic parameters have been investigated by nailfold capillaroscopy while digital laser-Doppler was used to study skin flowmetry. The results have been compared with a control group. Capillaroscopic remarkers showed an architecturally disorganized microvasculature with aspects related to a reduced compactness of the microvasculature unit with a significatively higher score compared with controls (7.3 +/- 2.9 vs 3.6 +/- 1 p less than 0.0005). Laser-Doppler flowmetry showed a significatively reduced rest flow; ischemic test showed: spike time 48.9 +/- 36.9 vs 15.3 +/- 7.7 s (p less than 0.0005), hyperemic acme 6.6 +/- 2.7 vs 12.5 +/- 8.4 UP (p less than 0.002); % increase 32.1 +/- 20.2 vs 51.5 +/- 15.4 (p less than 0.002). Thermic test showed a significatively higher thermic acme 8.7 +/- 4.2 vs 12.6 +/- 9.11 UP (p less than 0.05). These results appeared to be correlated with stage pathology as it was observed a severe microvasculature disorders in MVPS. Therefore we suppose that a phenotypic continuum may exist between MS and MVP.
Adult↗
Effects of neural blockade and general anesthesia on the laser-Doppler skin blood flow waves recorded from the finger or toe.
Effects of neural blockade and general anesthesia on the basic wave (BW) and the reflex wave (RW) among the laser-Doppler (L-D) skin blood flow waves recorded on the finger or toe were studied in 2 volunteers and 42 patients. The BW was continuous, rhythmic and independent of respiratory movements. The RW, which was induced by a deep inspiration or a snapping sound, was a transient marked reduction in blood flow. The BW was almost flattened and the RW was no longer induced at the finger under complete wrist block (n = 2), or under cervical or upper thoracic epidural anesthesia extended caudally over T7 (n = 2). On the other hand, the BW was still detected with reducing frequency and the RW could be provoked with one exception at the finger on the side with a sympathetic ganglion block at the C6 vertebral level (n = 14). The BW and RW at the toe were retained under lumbar subdural anesthesia (n = 6) as well. However, under the combination of lumbar subdural anesthesia and lower thoracic epidural anesthesia extending rostrally over T4 (n = 6), both the BW and the RW disappeared at the toe. In the course of deepening nitrous oxide/enflurane anesthesia (n = 10), the BW gradually reduced in frequency until it was almost flattened, and it became difficult to provoke the RW. L-D flowmetry of the finger or toe could be a useful clinical measure for detecting the presence or absence of sympathetic function controlling cutaneous vasomotion.
Adult↗
Current status of noninvasive tests in the diagnosis of peripheral arterial disease.
In this review of the current status of the vascular laboratory, the major emphasis has been upon those tests that have become well-established and documented, including resting pressure, pulse volume measurements, velocity studies, and three stress measurements--exercise ankle pressure, postocclusive reactive hyperemia, and the toe pulse reappearance time. Additional technology that may have application to peripheral arterial disease includes photoplethysmography, transcutaneous oxygen tension, laser-Doppler velocimetry, fluorescein angiography, infrared thermography, and transcutaneous electromagnetic flowmetry. These techniques, which are currently in development and experimental trial, were not discussed but are likely to provide significant additional information. The future role of the vascular diagnostic laboratory in the area of peripheral arterial occlusive disease appears clear. It has already become a standard resource of the community hospital and tertiary referral center. Its functions will become more and more generally accepted with time as newly graduating physicians who have been exposed to this technology enter the practice of medicine. It should permit obtaining an evaluation of all patients at the expert level, aid in the education of all physicians concerned with peripheral arterial disease, and play an important part in guaranteeing a higher level of patient care than has heretofore been available.
Arterial Occlusive Diseases↗