Valores de referencia del Doppler fetal en el Instituto Nacional de Parinatología Isidro Espinosa de los Reyes / Reference values of fetal Doppler at the Instituto Nacional de Perinatología Isidro Espinosa de los Reyes

Resumen OBJETIVO: Establecer los valores de referencia del índice de pulsatilidad con Doppler pulsado en la valoración materna y fetal de los embarazos en seguimiento entre las 18 y 39 semanas de gestación. MATERIALES Y MÉTODOS: Estudio descriptivo y transversal, efectuado en pacientes con embarazo único, entre las 18 a 40 semanas, que acudieron al Departamento de Medicina Materno Fetal del Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, entre los meses de septiembre de 2017 a mayo de 2018. La evaluación Doppler se practicó con medición del índice de pulsatilidad de las arterias uterinas, umbilical, cerebral media y conducto venoso en cada semana del embarazo. Se crearon tablas de referencia para cada semana de la gestación y se establecieron los percentiles 3, 5, 10, 90 y 95. RESULTADOS: Se registraron 862 pacientes. Los valores del índice de pulsatilidad de la arteria umbilical reportaron 17% en semanas tempranas de la gestación y 21% en edades gestacionales mayores. Los valores de la arteria umbilical fueron 3% menores en edades gestacionales tempranas y 10% menores al término del embarazo; 20% para la arteria umbilical, 15% para el conducto venoso y 10% para la arteria cerebral media. Los valores del índice de pulsatilidad medio de las arterias uterinas fueron mayores un 3% en edades gestacionales tempranas y 28% menores al término del embarazo. CONCLUSIONES: Los hallazgos de este estudio sugieren diferencias significativas con las poblaciones de Europa y Norteamérica; incluso difieren de los valores de referencia utilizados en la actualidad en la población mexicana, lo que supone una subestimación de las condiciones fetales o maternas al hacer las evaluaciones de la unidad fetoplacentaria.

Abstract OBJECTIVE: Establish the reference values for the pulsatility index using pulsed Doppler in the maternal and fetal assessment of pregnancies followed at 18 and 39 weeks of gestation. MATERIALS AND METHODS: Descriptive and cross-sectional study, carried out in patients with a singleton pregnancy, between 18 and 40 weeks, who attended the Department of Maternal Fetal Medicine of the National Institute of Perinatology, from September 2017 to May 2018. The Doppler evaluation was performed, with measurement of the pulsatility index of the uterine, umbilical, middle cerebral arteries, and venous duct in each week of pregnancy. Reference tables were created for each gestational age, establishing percentiles 3, 5, 10, 90 and 95. RESULTS: A total of 862 patients were registered. The umbilical artery pulsatility index values were reported to be 17% at early gestational ages and 21% at older gestational ages; Umbilical artery values were 3% lower at early gestational ages and 10% lower at term of pregnancy; 20% for the umbilical artery, 15% for the ductus venosus and 10% for the middle cerebral artery. The values of the mean pulsatility index of the uterine arteries were 3% higher at early gestational ages and 28% lower at the end of pregnancy. CONCLUSIONS: The findings of this study suggest significant differences with the populations of Europe and North America; They even differ from the reference values currently used in the Mexican population, which represents an underestimation of fetal and/or maternal conditions when carrying out evaluations of the feto-placental unit.

Improved Transcranial Doppler Waveform Analysis for Intracranial Hypertension Assessment in Patients with Traumatic Brain Injury.

BACKGROUND: Transcranial Doppler (TCD) is a noninvasive bedside tool for cerebral hemodynamic assessments in multiple clinical scenarios. TCD, by means of measuring systolic and diastolic blood velocities, allows the calculation of the pulsatility index (PI), a parameter that is correlated with intracranial pressure (ICP). Nevertheless, the predictive value of the PI for raised ICP appears to be low, as it is subjected to several, often confounding, factors not related to ICP. Recently, the pulsatile apparent resistance (PaR) index was developed as a PI corrected for arterial blood pressure, reducing some of the confounding factors influencing PI. This study compares the predictive value of PaR versus PI for intracranial hypertension (IH) (ICP > 20 mm Hg) in patients with traumatic brain injury. METHODS: Patients with traumatic brain injury admitted to the neurocritical care unit who required invasive ICP monitoring were included prospectively within 5 days of admission. TCD measurements were performed in both middle cerebral arteries, allowing calculations of the PI and PaR. The optimal cutoff, discriminative power of these parameters for ICP ≥ 20 mm Hg, was assessed by calculating the area under the receiver operator characteristics curve (AUC). RESULTS: In total, 93 patients were included. A total of 20 (22%) patients experienced IH during the recording sessions. The discriminative power was low for PI (AUC 0.63) but slightly higher for PaR (AUC 0.77). Nonparametric analysis indicated significant difference for PaR when comparing patients with (median 0.169) and without IH (median - 0.052, p = 0.001), whereas PI medians for patients with and without IH were 0.86 and 0.77, respectively (p = 0.041). Regarding subanalyses, the discriminative power of these parameters increased after exclusion of patients who had undergone a neurosurgical procedure. This was especially true for the PaR (AUC 0.89) and PI (AUC 0.72). Among these patients, a PaR cutoff value of - 0.023 had 100% sensitivity and 52.9% specificity. CONCLUSIONS: In the present study, discriminative power of the PaR for discriminating IH was superior to the PI. The PaR seems to be a reliable noninvasive parameter for detecting IH. Further studies are warranted to define its clinical application, especially in aiding neurosurgical decision making, following up in intensive care units, and defining its ability to indicate responses according to the therapies administered.

Evaluating feline lower urinary tract disease: Doppler ultrasound of the kidneys.

OBJECTIVES: Ultrasonography is used in the evaluation of urinary disorders, and the resistivity index (RI) and pulsatility index (PI) have been successfully used to detect early hemodynamic changes in the course of kidney diseases in humans and dogs. The aim of this study was to investigate RI and PI in cats with feline lower urinary tract disease (FLUTD). METHODS: Twenty-nine client-owned cats were selected and divided into a control group (CG; n = 10), a group of animals with obstructive FLUTD (OG; n = 11) and non-obstructive FLUTD (nOG; n = 8). Clinical, laboratory and ultrasound evaluations were performed in all cats. RESULTS: RI and PI values for cats in the CG were below the upper limit of normal suggested in other studies, while cats with FLUTD showed significantly higher values in the assessment of RI (P = 0.027 and P = 0.034, respectively) and PI (P = 0.044 and P = 0.048, respectively) of the right and left kidneys. CONCLUSIONS AND RELEVANCE: Alteration in renal blood flow was observed in cats with lower urinary tract disorders, even in the nOG group. To the best of our knowledge, this is the first report of renal blood flow changes related to non-obstructive FLUTD.

Accuracy of Doppler assessment of the uterine arteries in healthy girls for the diagnosis of pubertal onset.

PURPOSE: To evaluate the accuracy of the uterine artery pulsatility index (PI) for the diagnosis of pubertal onset in girls. METHODS: Cross-sectional study of girls with normal pubertal development. Puberty was diagnosed by the presence of Tanner breast development score ≥2. All girls underwent pelvic ultrasound and Doppler imaging of the uterine arteries. We evaluated the uterine artery PI and uterine, endometrial, and ovarian measurements. We used ROC curves with cutoffs determined by Youden index for data analysis. RESULTS: We included 169 girls aged 5-16 years who underwent 202 pelvic ultrasound examinations. Prepubertal girls had a significantly higher mean PI (6.70 ± 2.15) than girls in initial puberty (4.14 ± 1.55) and in late puberty (2.81 ± 1.05) (P < 0.001 for all comparisons), which reflects a progressive increase in blood flow to the uterus with the progression of puberty. ROC curve analysis showed that the PI was able to identify the onset of puberty with a mean area under the curve of 0.838 ± 0.04 (P < 0.001), and the PI cutoff point of 5.05 had a sensitivity of 77%, specificity of 85%, positive predictive value (PPV) of 92%, and accuracy of 79%. The combination of PI < 5.05 plus uterine volume >3.75 cm³ had a sensitivity of 73%, specificity of 95%, PPV of 97%, and accuracy of 79% to detect initial puberty. CONCLUSIONS: We found a significant reduction in the PI during pubertal development, which can possibly be a valuable noninvasive tool in the evaluation of pubertal disorders, alone or in combination with uterine and ovarian volumes.

Doppler de arteria umbilical en fetos con síndrome de Down / Umbilical artery Doppler in fetuses with Down syndrome

INTRODUCCIÓN: La aneuploidía más común entre los recién nacidos vivos es el síndrome de Down (SD). En estos niños el crecimiento está disminuido, con una frecuencia del 25% de restricción del crecimiento intrauterino, pero no se ha establecido el papel de la insuficiencia placentaria. El objetivo es estudiar la resistencia placentaria a través del Doppler de arteria umbilical con índice de pulsatilidad (IP) y el tiempo medio de desaceleración (t/2), y el posible efecto de la insuficiencia placentaria en fetos con SD. MÉTODO: Se realizó Doppler en la arteria umbilical en 78 fetos con SD, se midieron el IP y el t/2, y se compararon los resultados con los pesos de nacimiento. RESULTADOS: Se estudiaron 78 fetos con SD con 214 mediciones Doppler. El t/2 y el IP estaban alterados en el 71,5% y el 65% de las mediciones, respectivamente. La incidencia de t/2 alterado aumenta con la edad gestacional desde un 28,6% a las 15-20 semanas hasta un 89,3% sobre las 36 semanas (p < 0,01); cifras similares se observan para el IP. La clasificación de los pesos fue: 64% adecuados, 12% grandes y 24% pequeños para la edad gestacional. La última medición de t/2 antes del parto era normal en el 17% y estaba alterada en el 83%. En el caso del IP, los valores fueron normales en el 27% y anormales en el 73%. El peso de nacimiento, la edad gestacional y el porcentaje de niños adecuados para la edad gestacional eran significativamente mayores en el grupo con Doppler normal que en el grupo con Doppler alterado. El z-score del t/2 estaba marcadamente alterado (−2.23), pero el del peso de nacimiento solo estaba algo disminuido (−0,39). La mortalidad perinatal fue del 10%, significativamente mayor cuando el flujo diastólico era ausente o reverso. CONCLUSIONES: El estudio demuestra que los fetos con SD tienen una alta incidencia de alteración del Doppler umbilical para el IP y el t/2, lo cual sugiere una insuficiencia placentaria grave. Este deterioro parece iniciarse hacia el final del segundo trimestre y aumenta con la edad gestacional. Sin embargo, en estos fetos, la insuficiencia placentaria produce una ligera caída en el crecimiento fetal. Como hipótesis general pensamos que en los fetos con SD hay datos claros de insuficiencia placentaria, pero habría algún factor que les protegería de una restricción grave del crecimiento.

INTRODUCTION: The most common aneuploidy in live newborns is Down syndrome (DS), in these children growth is decreased, with a frequency of 25-36% of fetal growth restriction (FGR); however, it is not established the role of placental insufficiency. The objective is to study the Doppler of the umbilical artery with pulsatility index (PI) and half peak systolic velocity (hPSV) deceleration time and the possible role of placental insufficiency in fetuses with DS. METHOD: Doppler was performed in fetuses with DS, the umbilical artery and IP and hPSV were measured, and the results were compared with birth weights. RESULTS: 78 fetuses with DS were studied with 214 Doppler measurements. hPSV and the IP were altered in 71.5% and 65% of the measurements; the incidence of abnormal hPSV increases with gestational age from 28.6% between 15 to 20 weeks, to 89.3% over 36 weeks (p < 0.01), similar figures are observed with respect to the PI. The weight classification was: 24% of FGR, 12% of great for age and 64% of adequate for gestational age (AGA). The last measurement of hPSV before delivery was normal in 17% of the fetuses and was abnormal in 83%, in the case of PI the normal and abnormal values were 27 and 73%, respectively. Birth weight, gestational age, and the percentage of AGA children were significantly higher in the normal Doppler group than in the abnormal Doppler group. The hPSV z-score was markedly altered (−2.23), but the birth weight z-score is slightly decreased (−0.39). Perinatal mortality is 10% and is significantly higher when diastolic flow is absent or reverse. CONCLUSIONS: The study shows that DS fetuses have a high incidence of abnormal umbilical Doppler measured with IP and hPSV, which suggests severe placental insufficiency, this deterioration seems to start towards the end of the second trimester and increases with gestational age. However, in these fetuses, placental insufficiency causes a discrete drop in fetal growth. As a general hypothesis, we think that there is clear evidence of placental insufficiency in fetuses with DS, but there would be some factor that would protect these fetuses from severe growth restriction.

Cerebral hemodynamics in the non-alcoholic fatty liver.

INTRODUCTION AND OBJECTIVES: The association between non-alcoholic fatty liver disease and cerebral hemodynamics arises from cardiovascular damage mechanisms such as endothelial dysfunction, arterial wall increased stiffness, high thickness of the intimate index of the internal carotid artery, left ventricular hypertrophy, left diastolic dysfunction, calcification coronary arteries and increased epicardial fat. The multidirectional relationship between systemic inflammation and lipid metabolism constitutes a common and simultaneous mechanism that causes vascular damage. This study aims to provide insight into the relationship between non-alcoholic fatty liver disease and the function of systemic circulation and cerebral circulation using Doppler ultrasound. PATIENTS AND METHODS: Is an observational, cross-sectional, prospective, comparative study conducted at Medica Sur Hospital. Thirty-five patients were selected consecutively. The patients consulted neurological service for various symptoms without severity criteria, such as vertigo, primary headache and balance disturbances. RESULTS: There is a difference in the variables mean of the right MCA PI (p = 0.023), left MCA PI" (p = 0.004), and left VA PI (p = 0.036) between the control and NAFLD groups. The correlation analysis between these variables and the CAP showed a positive correlation of the three variables with the CAP, "right MCA PI" (r = 0.384), left MCA PI "(r = 0.509) and" left VA PI " (r = 0.551). CONCLUSIONS: This study demonstrates a subclinical process of the middle cerebral artery in subjects with NAFLD, which suggests it may be involved in the disease development and points the need to make decisions for this liver manifestation prevention and treatment.

International gestational age-specific centiles for umbilical artery Doppler indices: a longitudinal prospective cohort study of the INTERGROWTH-21st Project.

BACKGROUND: Reference values for umbilical artery Doppler indices are used clinically to assess fetal well-being. However, many studies that have produced reference charts have important methodologic limitations, and these result in significant heterogeneity of reported reference ranges. OBJECTIVES: To produce international gestational age-specific centiles for umbilical artery Doppler indices based on longitudinal data and the same rigorous methodology used in the original Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. STUDY DESIGN: In Phase II of the INTERGROWTH-21st Project (the INTERBIO-21st Study), we prospectively continued enrolling pregnant women according to the same protocol from 3 of the original populations in Pelotas (Brazil), Nairobi (Kenya), and Oxford (United Kingdom) that had participated in the Fetal Growth Longitudinal Study. Women with a singleton pregnancy were recruited at <14 weeks' gestation, confirmed by ultrasound measurement of crown-rump length, and then underwent standardized ultrasound every 5±1 weeks until delivery. From 22 weeks of gestation umbilical artery indices (pulsatility index, resistance index, and systolic/diastolic ratio) were measured in a blinded fashion, using identical equipment and a rigorously standardized protocol. Newborn size at birth was assessed using the international INTERGROWTH-21st Standards, and infants had detailed assessment of growth, nutrition, morbidity, and motor development at 1 and 2 years of age. The appropriateness of pooling data from the 3 study sites was assessed using variance component analysis and standardized site differences. Umbilical artery indices were modeled as functions of the gestational age using an exponential, normal distribution with second-degree fractional polynomial smoothing; goodness of fit for the overall models was assessed. RESULTS: Of the women enrolled at the 3 sites, 1629 were eligible for this study; 431 (27%) met the entry criteria for the construction of normative centiles, similar to the proportion seen in the original fetal growth longitudinal study. They contributed a total of 1243 Doppler measures to the analysis; 74% had 3 measures or more. The healthy low-risk status of the population was confirmed by the low rates of preterm birth (4.9%) and preeclampsia (0.7%). There were no neonatal deaths and satisfactory growth, health, and motor development of the infants at 1 and 2 years of age were documented. Only a very small proportion (2.8%-6.5%) of the variance of Doppler indices was due to between-site differences; in addition, standardized site difference estimates were marginally outside this threshold in only 1 of 27 comparisons, and this supported the decision to pool data from the 3 study sites. All 3 Doppler indices decreased with advancing gestational age. The 3rd, 5th 10th, 50th, 90th, 95th, and 97th centiles according to gestational age for each of the 3 indices are provided, as well as equations to allow calculation of any value as a centile and z scores. The mean pulsatility index according to gestational age = 1.02944 + 77.7456*(gestational age)-2 - 0.000004455*gestational age3. CONCLUSION: We present here international gestational age-specific normative centiles for umbilical artery Doppler indices produced by studying healthy, low-risk pregnant women living in environments with minimal constraints on fetal growth. The centiles complement the existing INTERGROWTH-21st Standards for assessment of fetal well-being.

Prognostic utility of cervical length and uterine artery pulsatility index for imminent preterm delivery in symptomatic patients / Utilidad pronóstica de la longitud cervical e índice de pulsatilidad de la arteria uterina en el parto pretérmino inminente en pacientes sintomáticas

ABSTRACT Objective : To establish the prognostic usefulness of cervical length and uterine artery pulsatility index for imminent preterm delivery in symptomatic patients. Design : Case-control study. Setting: Central Hospital "Dr. Urquinaona ", Maracaibo, Venezuela. Participants : Patients with preterm delivery within 7 days (group A) and pregnant women with preterm delivery within more than 7 days (group B). Methods : Cervical length and uterine artery pulsatility index were determined at hospital admission and all were followed until delivery. Main outcome measures: General characteristics, cervical length, uterine artery pulsatility index, imminent preterm delivery, and prognostic efficacy. Results : 119 participants were assigned to group A and 362 patients to group B. Cervical length was lower in group A, and the uterine artery pulsatility index was higher compared with group B (p <0.0001). Cervical length showed an area under the curve of 0.972, while the uterine artery pulsatility index presented an area under the curve of 0.843. The difference between the two measurements was significantly different between groups A and B (p <0.001). Combination of both measurements showed a significantly lower value in prediction capacity (0.987) compared with both measurements individually (p <0.0001). Conclusion : The combined use of cervical length and pulsatility index of the uterine artery was useful in the prediction of imminent preterm delivery in symptomatic patients.

RESUMEN Objetivo . Establecer la utilidad pronóstica de la longitud cervical e índice de pulsatilidad de la arteria uterina en el parto pretérmino inminente en pacientes sintomáticas. Diseño . Estudio de casos-controles. Institución. Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Participantes . Pacientes con parto pretérmino en los siguientes 7 días (grupo A) y embarazadas con parto pretérmino más allá de los 7 días (grupo B). Métodos . Las mediciones de la longitud cervical e índice de pulsatilidad de la arteria uterina se realizaron al ingreso de las gestantes al hospital y todas fueron seguidas hasta el parto. Principales medidas de resultado. Características generales, longitud cervical, índice de pulsatilidad de la arteria uterina, parto pretérmino inminente y eficacia pronóstica. Resultados . 119 participantes fueron asignadas al grupo A y 362 pacientes al grupo B. La longitud cervical fue menor en el grupo A, mientras que el índice de pulsatilidad de la arteria uterina fue mayor comparado con el grupo B (p < 0,0001). La medición de la longitud cervical presentó un valor de área bajo la curva de 0,972, mientras que el índice de pulsatilidad de la arteria uterina mostró un área bajo la curva de 0,843. La diferencia de la diferencia entre ambas mediciones se consideró estadísticamente significativa (p < 0,001). La combinación de ambas mediciones tuvo un valor bajo la curva significativamente superior en capacidad de predicción (0,987) comparada con ambas mediciones en forma individual (p < 0,0001). Conclusión . El uso combinado de las mediciones de la longitud cervical y el índice de pulsatilidad de la arteria uterina resultó útil en la predicción de parto pretérmino inminente en pacientes sintomáticas.

Uterine hemodynamics during a short-term progesterone synchronization protocol in ewes.

Twenty-eight pluriparous and non-lactating Santa Inês sheep were synchronized with vaginal sponge and an intramuscular (IM) injection of 37.5 µg of cloprostenol on random days of the estrous cycle (D0); day 6 (D6), at 7:00 am, the devices were removed, and after 24 h (D7), GnRH analog (25 µg of lecirelin) was administrated. Fixed-time artificial insemination (FTAI) with cervical traction by the transcervical route was performed 52 to 58 h after sponge removal. Doppler velocimetry of both uterine arteries was performed on D0, D2, D4, and the morning of D6 (every 48 h), and then every 12 h from D6 to D8 (7:00 a.m. and 7:00 p.m.). We analyzed the peak systolic velocity (PSV), end-diastolic velocity (EVD), time-averaged maximum and mean velocity (TAMAX, TAMEAN), pulsatility index (PI), resistance index (RI), systolic/diastolic ratio (S/D), arterial diameter (AD), and blood flow volume (BFV), with the objective of evaluating the hemodynamic behavior of blood flow velocity parameters of the uterine artery during a short-term progesterone synchronization protocol in ewes. With respect to phases, we noted increases in the means of TAMAX and TAMEAN and decreases of EDV, PI, and RI (P < 0.05). S/D, EDV, TAMEAN, PI, RI, SD, AD, and BFV showed differences between the time of progesterone insertion and the estimated time of ovulation (which was considered the last evaluation) (P < 0.05). The PI and RI values were different when comparing the times of insertion and withdrawal of the progesterone device (PI 2.53-1.54 and RI 0.76-0.68) (P < 0.05). The PI was different with respect to side (P < 0.001), but no side effect was seen in the RI. In conclusion, the two uterine arteries behave differently under the effect of progesterone (intravaginal sponges) and the effect of estradiol during the follicular phase, and estrous phase was responsible for increasing uterine blood flow.

Umbilical artery pulsatility index and half-peak systolic velocity deceleration time in fetuses with trisomy 21.

Objective: To analyze placental vascular resistance and the role of placental insufficiency in the etiology of reduced fetal growth in fetuses with trisomy 21 as determined by umbilical artery (UA) Doppler velocimetry.Methods: Second- and third-trimester UA Doppler ultrasound studies were performed in fetuses with trisomy 21 at the time of clinically indicated obstetric ultrasound assessment. The UA pulsatility index (PI) and half-peak systolic velocity deceleration time (hPSV-DT) were measured and recorded. Perinatal outcome was reviewed and the results from UA Doppler velocimetry were compared with birthweight according to gestational age at the time of the delivery.Results: A total of 60 fetuses with trisomy 21 were studied and information from 147 UA Doppler studies was analyzed. Overall, at least one of the UA PI and hPSV-DT values was abnormal in 82% (n = 49) and 90% (n = 54) of the cases, respectively. The incidence of abnormal UA PI values increased with gestational age from 39% (7/18) before 21 weeks to 78% (18/23) after 35 weeks (p < .05). The increase was even more evident for UA hPSV-DT values from 28% (5/18) before 20 weeks to 91% (21/23) after 35 weeks (p < .01). After exclusion of four fetuses with hydrops or isolated hydrothorax/ascites, 16 (29%) were classified at birth as small for gestational age (SGA), 34 (61%) as adequate for gestational age, and six (11%) as large for gestational age, with a mean birthweight z-score of -0.36. When only considering the last Doppler ultrasound assessment prior to delivery, UA PI and hPSV-DT values were abnormal in 73% (41/56, mean z-score = +1.72) and 82% (46/56; mean z-score = -2.18) of the cases, respectively. Mean gestational age at delivery and birth weight were significantly lower in the group with abnormal compared to normal UA PI and hPSV-DT values. Similarly, the incidence of SGA fetuses was significantly higher in the group with abnormal compared to normal UA PI and hPSV-DT values, with 94 (n = 15) and 100% of the 16 SGA newborn infants having abnormal UA PI and hPSV-DT values prior to delivery, respectively.Conclusions: Trisomy 21 fetuses have a progressively higher incidence of abnormal UA impedance indices throughout pregnancy, which suggests developing placental vascular resistance as the pregnancy progresses. This alteration likely begins around the mid second trimester and increases with gestational age; however, increasing placental vascular resistance seems to produce a discrete decrease in fetal growth, despite severe alteration of the UA Doppler impedance indices. As a general hypothesis, we postulate that trisomy 21 fetuses have increasing placental vascular resistance but there may be some factors that protect these fetuses from severe fetal growth restriction.

Dopplerfluxometria da artéria femoral de cães adultos hígidos (Canis lupus familiaris) / Femoral artery Dopplerfluxometry of adult healthy dogs (Canis lupus familiaris)

Background: In Veterinary Medicine, there are several methods for early and accurate assessment of blood flow dynamics. The Dopplerfluxometry can access the peak systolic velocity, mean velocity and end diastolic velocity, including Resistive Index and Pulsatility Index. Normal values of Dopplerfluxometry in healthy dogs allow the identification of vascular abnormalities and authors’ knowledge there are no reference regarding the values of Dopplerfluxometry of the femoral artery in healthy dogs. The aim of the study was to assess the femoral Dopplerfluxometry of adult healthy dogs by Resistive Index, Pulsatility Index, systolic and diastolic velocities, and femoral artery diameter.Materials, Methods & Results: Eighteen healthy intact beagle dogs, male and female, aging from 2 to 4 years old (mean ± SD: mean 3 ± 0.8 years), weighing from 10.1-17.9 kg [22.3-39.5 lb] [mean ± SD: 14.3 ± 2.7 kg (31.5 ± 5.96 lb)] were used. The dogs underwent to physical examination, complete blood cell count, serum biochemistry examination urinalysis, and radiographs examination, muscular and cardiac evaluation. Females had to be in anestrous. All dogs were submitted to right femoral artery Dopplerfluxometry. The dogs were positioned in dorsal recumbency by one person without any chemical restraint. A high definition ultrasound device equipped with a 3 - 13 MHz multi-frequency linear transducer was used. The right femoral artery was identified with the transducer positioned transversely on the right triangle femoral area. Peak systolic velocity, end-diastolic velocity was measured. The Resistivity Index and Pulsatility Index were calculated automatically by the ultrasound machine software. Three measurements were obtained with the Doppler spectrum. The values of peak systolic velocity, end-diastolic velocity, Resistivity Index, Pulsatility Index and femoral artery diameter were expressed as Mean ± Standard Deviation (SD).[...]

Dopplerfluxometria da artéria femoral de cães adultos hígidos (Canis lupus familiaris) / Femoral artery Dopplerfluxometry of adult healthy dogs (Canis lupus familiaris)

Background: In Veterinary Medicine, there are several methods for early and accurate assessment of blood flow dynamics. The Dopplerfluxometry can access the peak systolic velocity, mean velocity and end diastolic velocity, including Resistive Index and Pulsatility Index. Normal values of Dopplerfluxometry in healthy dogs allow the identification of vascular abnormalities and authors knowledge there are no reference regarding the values of Dopplerfluxometry of the femoral artery in healthy dogs. The aim of the study was to assess the femoral Dopplerfluxometry of adult healthy dogs by Resistive Index, Pulsatility Index, systolic and diastolic velocities, and femoral artery diameter.Materials, Methods & Results: Eighteen healthy intact beagle dogs, male and female, aging from 2 to 4 years old (mean ± SD: mean 3 ± 0.8 years), weighing from 10.1-17.9 kg [22.3-39.5 lb] [mean ± SD: 14.3 ± 2.7 kg (31.5 ± 5.96 lb)] were used. The dogs underwent to physical examination, complete blood cell count, serum biochemistry examination urinalysis, and radiographs examination, muscular and cardiac evaluation. Females had to be in anestrous. All dogs were submitted to right femoral artery Dopplerfluxometry. The dogs were positioned in dorsal recumbency by one person without any chemical restraint. A high definition ultrasound device equipped with a 3 - 13 MHz multi-frequency linear transducer was used. The right femoral artery was identified with the transducer positioned transversely on the right triangle femoral area. Peak systolic velocity, end-diastolic velocity was measured. The Resistivity Index and Pulsatility Index were calculated automatically by the ultrasound machine software. Three measurements were obtained with the Doppler spectrum. The values of peak systolic velocity, end-diastolic velocity, Resistivity Index, Pulsatility Index and femoral artery diameter were expressed as Mean ± Standard Deviation (SD).[...](AU)

Cerebral pulsatility index in older adults with silent lacunar strokes (The Atahualpa Project) / Índice de pulsatilidad cerebral en adultos mayores con infarto lacunar silente (Proyecto Atahualpa)

ABSTRACT Background: Diagnosis of silent lacunar infarcts is complicated in remote rural areas where MRI is not available. Hospital series have suggested an association between the pulsatility index of intracranial arteries - as assessed by transcranial Doppler - and some neuroimaging signatures of cerebral small vessel disease. We aimed to assess the reliability of cerebral pulsatility indices to identify candidates for MRI screening in population-based studies assessing prevalence of silent lacunar infarctions. Methods: A random sample of stroke-free Atahualpa residents aged ≥60 years investigated with MRI underwent transcranial Doppler for calculating the pulsatility index (PI) of the middle cerebral artery (MCA). For each person, mean PI was obtained by averaging both MCAs. Using conditional logistic regression for matched pairs data, we evaluated whether the pulsatility index of both MCAs correlate with silent lacunar infarcts. Results: Silent lacunar infarcts were noticed in 28 (12%) of 234 scanned persons. Six of them were excluded due to poor insonation through transtemporal windows. The remaining 22 participants were considered case-patients and were matched 1:1 with individuals free of infarcts (controls). Moderate-to-severe white matter hyperintensities were noticed in 12 (55%) case-patients and 7 (32%) controls (p=0.228). The mean MCA PI value in the 44 participants was 1.15 ± 0.21, with no difference found across case-patients and controls, after adjustment for white matter hyperintensities (β coefficient: 3.361, 95% C.I.: -0.693 to 7.417, p=0.104). Conclusions: Cerebral PI should not be used to identify candidates for MRI screening in population-based studies assessing the burden of silent lacunar infarcts.

RESUMEN Antecedentes: El diagnóstico de infartos lacunares silentes es complicado en áreas rurales donde no se dispone de IRM. Series hospitalarias han sugerido una asociación entre el índice de pulsatilidad (IP) de las arterias intracraneales -evaluadas mediante Doppler transcraneal- y algunas de las imágenes sugestivas de enfermedad cerebral de pequeños vasos. Nuestro objetivo fue evaluar la confiabilidad del IP para identificar candidatos para la práctica de IRM en estudios poblacionales que evalúen prevalencia de infartos lacunares. Métodos: Una muestra aleatoria de residentes de Atahualpa sin evidencia de ictus, con edad ≥60 años e investigados con IRM, fueron sometidos a Doppler transcraneal, para calcular el IP de las arterias cerebrales medias. El IP medio se obtuvo promediando el IP de ambas arterias cerebrales medias. Usando regresión logística condicional, se evaluó si el IP de las arterias cerebrales medias se correlacionó con la presencia de infartos lacunares. Resultados: Se detectaron infartos lacunares silentes en 28 (12%) de 234 personas exploradas. Seis de ellos fueron excluidos debido a mala insonancia a través de ventanas transtemporales. Los 22 participantes restantes se consideraron casos y se emparejaron 1: 1 con individuos libres de infartos (controles). Se observaron hiperintensidades de sustancia blanca de moderada a grave en 12 (55%) pacientes y 7 (32%) controles (p = 0.228). El valor medio de IP en los 44 participantes fue de 1,15 ± 0,21, sin diferencias entre pacientes y controles, después del ajuste para hiperintensidades de sustancia blanca (coeficiente β: 3,361, 95% C.I.: -0,693 a 7,417, p = 0,104). Conclusiones: El IP cerebral no se debe utilizar para identificar candidatos para el cribado de IRM en estudios poblacionales que evalúen la presencia de infartos lacunares silentes.

B-mode and Doppler ultrasound of chronic kidney disease in dogs and cats.

Ultrasound is the imaging test of choice for renal evaluation, because it provides information about the position, size, shape, internal architecture and hemodynamics of the kidneys without harming the patient. In chronic kidney disease, the main findings observed in B-mode ultrasound images are increased cortical echogenicity, loss of corticomedullary differentiation, reduced renal volume and irregular renal contour, and when these changes are associated, they are indicative of end-stage renal disease. However, the cause of kidney disease cannot be determined by ultrasonography, but must be confirmed by means of biopsy, although the presence of ultrasonographic changes indicative of the end-stage of the disease may contraindicate this procedure. The Doppler ultrasound test complements the ultrasonic B-mode examination and enables the assessment of renal perfusion based on a calculation of the hemodynamic indices, which are increased in cases of chronic kidney lesions, with higher values ​​in the most severe cases. Thus, ultrasound examinations are not only useful in diagnostics but also play an important role in defining the prognosis of patients with chronic kidney disease.

Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja).

Twenty harpy eagles (Harpia harpyja) without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI) and pulsatility index (PI) were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation.

Valores de referencia del índice de pulsatilidad de la arteria uterina durante el embarazo

Objetivo: Establecer los valores de referencia del índice de pulsatilidad promedio de la arteria uterina entre las 11 y 40 semanas de gestación. Métodos: Se realizó un estudio prospectivo, transversal y no experimental. Se evaluaron con ultrasonido doppler las arterias uterinas de 559 gestantes con fetos únicos y con crecimiento normal entre las semanas 11 a 40 de gestación. Se calculó el índice de pulsatilidad promedio (índice de pulsatilidad promedio de las uterinas igual al índice de pulsatilidad de la uterina derecha más el índice de pulsatilidad de la izquierda dividido entre dos), y se identificó la prevalencia de muesca protodiastólica en cada semana de gestación. Para la obtención de los valores normales del índice de pulsatilidad promedio se calculó la mediana como medida de tendencia central y los percentiles como medidas de posición. El estudio se realizó en el Hospital “Dr. Adolfo Prince Lara”. Resultados: Los valores de índice de pulsatilidad de ambas arterias uterinas evidenciaron correlación inversa con la edad gestacional. La prevalencia unilateral y bilateral de la muesca protodiastólica durante la gestación fue de 19,6 % y 17,45 % respectivamente. Conclusión: El índice de pulsatilidad promedio de las uterinas muestra una disminución progresiva hasta las últimas etapas del embarazo.

Objective: To establish the normal reference values of the mean pulsatility index of the uterine artery between 11 and 40 gestation weeks. Methods: A prospective type, cross-sectional and non-experimental study was performed. Doppler ultrasound was used to evaluate uterine arteries of 559 pregnant women with singleton fetuses with normal growth between weeks 11-40 of gestation. Average pulsatility index (Average pulsatility index = pulsatility index of right uterine artery plus pulsatility index of left uterine artery/2) was calculated and the prevalence of early diastolic notch in each week of gestation was identified. To obtain normal values of average pulsatility index, the median was calculated as a measure of central tendency and percentiles as measures of position. Seting: Hospital “Dr. Adolfo Prince Lara. Results: The pulsatility index values of both uterine arteries showed inverse correlation with gestational age. The prevalence of unilateral and bilateral early diastolic notch during pregnancy was 19.6% and 17.45% respectively. Conclusions: The Average Pulsatility index of the uterine arteries shows a progressive decline until the late stages of pregnancy.

Brachial artery Doppler flux parameters before and after hot flush in Mexican postmenopausal women: preliminary report.

OBJECTIVE: To analyse brachial artery flux parameters in postmenopausal women before and after hot flush. MATERIAL AND METHODS: Two groups of postmenopausal women were studied: Group I, without vasomotor symptoms (n = 10) and Group II, with vasomotor symptoms (n = 10). In all them a brachial artery Doppler ultrasound was done, measuring before and after hyperaemic stimulus of the arterial diameter (AD), the pulsatility index (PI), and the resistive index (RI). In Group I, measurements were done at baseline and five minutes after. In Group II, measurements were at baseline, and one and five minutes after the hot-flush. Comparison between the groups was done with Mann-Whitney U test, and within the groups with Wilcoxon test. RESULTS: No differences were found among the groups in Doppler parameters. When comparing each group separately, in Group I, at baseline and at five minutes measurements, the AD was greater after the hyperaemic stimulus than before it. In group II at baseline, the PI was significantly greater after the hyperaemic stimulus than before to it. At the first and fifth minute, the AD was significantly greater after the hyperaemic stimulus than before to it. CONCLUSIONS: No differences were found between those who did not have and those who had hot flushes.

Brachial artery flow mediated dilation and pulsatility index change as independent predictors for hypertensive disorders in the second trimester of pregnancy.

OBJECTIVE: To assess brachial artery flow mediated dilatation (FMD) and pulsatility index change (PIC) as independent parameters for prediction hypertensive disorders (preeclampsia - PE and gestational hypertension - GH) in the second trimester of pregnancy. STUDY DESIGN: We performed a prospective cohort study with 372 singleton pregnant women who underwent routine second trimester morphology scan. FMD and PIC were measured immediately after the ultrasound scan using the following formulas: FMD (%)=[(post occlusion arterial diameter-baseline arterial diameter)/baseline arterial diameter]×100 and PIC (%)=[(pulsatility index pre-pulsatility index post)/pulsatility index pre]. The control and hypertensive disorder groups were compared using the Kruskal-Wallis to continue variables and Chi-square and Fisher exact tests to categorical variables. We assessed the predictive accuracy of FMD and PIC by the area under the receiver operating characteristics (ROC) curve with its respective 95% confidence interval (CI). RESULTS: We did not observe statistical difference between control and hypertensive disorder groups regarding the FMD and PIC (p=0.17 and p=0.38, respectively). Areas under ROC curve for prediction of GH using FMD and PIC were 0.59 (CI95% 0.48-0.71) and 0.60 (CI95% 0.47-0.73), respectively. Areas under ROC curve for prediction of PE using FMD and PIC were 0.55 (CI95% 0.46-0.64) and 0.52 (CI95% 0.61-0.69), respectively. CONCLUSION: Brachial artery FMD and PIC as independent parameters did not show good prediction for hypertensive disorders in the second trimester of pregnancy.

Hemodynamics of the pectinis oculi artery in American pekin ducks (Anas platyrhynchos domestica).

OBJECTIVE: To measure blood velocity parameters of the main detectable branch of the pectinis oculi artery and compare with values found in other arteries in other species to form a hypothesis of the function of the pecten oculi in birds. METHODS: Eleven American pekin ducks (Anas platyrhynchos domestica) without ocular diseases were examined with ocular Doppler ultrasonography. The pectinate artery resistive index (RI) and pulsatility index (PI) were calculated. RESULTS: The mean of RI and PI values resulted, respectively, in: left eye (0.43 ± 0.07; 0.58 ± 0.13), right eye (0.37 ± 0.09; 0.47 ± 0.14), and both eyes (0.40 ± 0.08; 0.53 ± 0.14). DISCUSSION: The low RI and PI values found in the main branch of the pectinis oculi artery compared with other arteries in other tissues suggest a high metabolic activity in the pecten oculi, and it could indicate a nutritional function and/or intraocular pressure regulation.

Disappointing reliability of pulsatility indices to identify candidates for magnetic resonance imaging screening in population-based studies assessing prevalence of cerebral small vessel disease.

BACKGROUND: Diagnosis of cerebral small vessel disease (SVD) is a challenge in remote areas where magnetic resonance imaging (MRI) is not available. Hospital-based studies in high-risk or stroke patients have found an association between the pulsatility index (PI) of intracranial arteries - as derived from transcranial Doppler (TCD) - and white matter hyperintensities (WMH) of presumed vascular origin. We aimed to assess the reliability of cerebral pulsatility indices to identify candidates for MRI screening in population-based studies assessing prevalence of SVD. METHODS: A representative sample of stroke-free Atahualpa residents aged ≥65 years investigated with MRI underwent TCD. Using generalized linear models, we evaluated whether the PI of major intracranial arteries correlate with WMH (used as a proxy of diffuse SVD), after adjusting for demographics and cardiovascular risk factors. RESULTS: Out of 70 participants (mean age 70.6 ± 4.6 years, 57% women), 28 (40%) had moderate-to-severe WMH. In multivariate models, there were no differences across categories of WMH in the mean PI of middle cerebral arteries (1.10 ± 0.16 vs. 1.22 ± 0.24, ß: 0.065, 95% confidence interval (CI): -0.084-0.177, P = 0.474) or vertebrobasilar arteries (1.11 ± 0.16 vs. 1.29 ± 0.27, ß: 0.066, 95% CI: -0.0024-0.156, P = 0.146). CONCLUSIONS: Cerebral PI should not be used to identify candidates for MRI screening in population-based studies assessing the burden of SVD.