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Biomedical subjects

E Krampl

Publications and source records attributed to E Krampl.

At least 19 recordsLinked to original sources

Can aneroid sphygmomanometers be used at altitude?

Mercury-independent devices are increasingly being used in clinical practice as mercury will soon be removed from clinical use as a result of environmental, health and safety concerns. The aim of this study was to evaluate the accuracy of a portable aneroid device in an adult population at high altitude by following the part of the protocol of the British Hypertension Society regarding comparison between device and observer. We examined 10 subjects in Cerro de Pasco, Peru, which is situated 4370 m above sea level. The aneroid device was initially calibrated at both high altitude and at sea level to ensure optimal function. Validation of the device was undertaken at high altitude by connecting it in parallel to two mercury sphygmomanometers. Eleven sequential same-arm measurements were taken from each subject by two trained observers, alternating between mercury sphygmomanometry and the aneroid device. Simultaneous mercury readings were also recorded for additional analysis. During calibration, all 60 comparisons between the aneroid and mercury sphygmomanometers were within 3 mm Hg both at sea level and at high altitude. At validation, the device achieved an A grade for both systolic and diastolic pressures and also fulfilled the requirements of the Association for the Advancement of Medical Instrumentation. The mean and standard deviation for systolic and diastolic pressures, respectively, were -1.32 (4.3) mm Hg and 3.7 (4.7) mm Hg in sequential analysis and -0.7 (2.6) mm Hg and -3.3 (2.7) mm Hg in simultaneous analysis. We conclude that the Riester-Exacta portable aneroid device can be recommended for use in an adult population at high altitude.

Adult↗

[Indications for fetal magnetic resonance imaging].

Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta.

Congenital Abnormalities↗

[Multiple pregnancy].

The incidence of multiple pregnancies has increased considerably over the past 20 years in the western world. The number of twin pregnancies has increased by approximately 25% and the rate of triplet and higher order multiple pregnancies has more than doubled. This is due to the use of ovarian hyperstimulation and assisted reproduction techniques, and to the increasing maternal age. Multiple pregnancy can be considered as the most important adverse outcome of infertility treatment. The main determinant for outcome and management of multiple pregnancies is the chorionicity. This can be determined by ultrasound until 14 weeks of gestation. Twenty percent of all twin pregnancies are monochorionic, and 15% of these develop severe twin to twin transfusion syndrome, which is best treated by LASER separation of the communicating blood vessels. Obstetric complications associated with multiple gestation also occur more frequently in monochorionic twins. They include increased incidence of preterm labor, intrauterine growth restriction and assisted or surgical delivery. Neonatal problems include low birthweight and increased prevalence of congenital malformations. Overall, there has been a decrease in neonatal mortality of twins and triplets over the past 10 years, which is mainly due to the enormous advances in neonatal intensive care.

Cross-Sectional Studies↗

Congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation.

Congenital lymphedema is an autosomal dominant condition characterized by chronic tissue swelling caused by deficient lymphatic drainage due to hypoplastic/aplastic lymphatic vessels and usually affecting the lower limbs. The locus of the gene has been identified in the long arm of chromosome 15. We report one case of congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation.

Adult↗

Haemorheological adaptation during pregnancy in a Latin American population.

OBJECTIVE: To investigate haemorheological changes during pregnancy in a Latin American population and compare to previously published data from Caucasian populations. DESIGN: Cross-sectional study. POPULATION: 75 pregnant women at 10-36 wk of gestation and 17 non-pregnant female controls in Lima, Peru. All the women and their ancestors for three generations were born and lived at sea level. METHODS: Viscosity, haematocrit and plasma fibrinogen, albumin and total protein concentrations were determined in blood samples obtained after an overnight period of fasting. RESULTS: At 10 wk of gestation, total protein concentration and plasma viscosity were above non-pregnant levels by about 15% and subsequently decreased linearly with gestation. Fibrinogen concentration was increased in the first trimester; it then decreased to a nadir at about 20 wk and subsequently increased. Albumin concentration decreased linearly with gestation. Haematocrit decreased from pre-pregnancy levels at 10 wk to a nadir at about 26 wk. Blood viscosity increased in the first trimester and then decreased with gestation to a nadir at about 26 wk. CONCLUSION: In the first trimester of pregnancy blood and plasma viscosity are increased and they subsequently fall with advancing gestation. Plasma viscosity reflects the changes in total protein concentration, and blood viscosity is dependent on the interplay of changes in plasma viscosity and haematocrit.

Adaptation, Physiological↗

Fetal Doppler velocimetry at high altitude.

OBJECTIVES: To determine impedance and velocity characteristics of the fetal circulation using Doppler ultrasound, at extremely high altitude (4300 m) in the Peruvian Andes compared to an ethnically similar population at sea level. METHODS: This was a cross-sectional study of 196 women resident at high altitude (Cerro de Pasco, 4300 m above sea level) and 196 women resident at sea level (Lima) with normal singleton pregnancies. Pulsatility index (PI), maximum velocity (Vmax) and minimum velocity (Vmin) in the umbilical artery, the descending aorta, the middle cerebral artery and the ductus venosus were compared between the two populations using fractional polynomial regression analysis. RESULTS: The PI was higher at high altitude than at sea level in the umbilical artery (regression coefficient = 0.112, P < 0.001), and not significantly different in the descending aorta, middle cerebral artery and ductus venosus. Vmax was lower at high altitude than at sea level in all three arterial vessels assessed; Vmin was lower in two: the umbilical artery and the descending aorta. The high-altitude/sea-level ratios for umbilical artery Vmax and Vmin were 0.93 and 0.82, respectively (P < 0.001 for each), the ratios for descending aorta Vmax and Vmin were 0.93 and 0.89, respectively (P = 0.003 and P < 0.001, respectively), and the regression coefficient for the middle cerebral artery Vmax was -2.844 (P = 0.003). There was no significant difference in the middle cerebral artery Vmin or in the ductus venosus Vmax and Vmin. CONCLUSIONS: Despite the lower ambient oxygen at high altitude and an increase in umbilical artery PI, the fetal circulation does not exhibit a 'brain sparing effect'. This and the overall decrease in blood flow velocities in the fetal circulation at high altitude may be due to the increased fetal hematocrit, which will result in increased blood viscosity.

Adult↗

Measurement of fetal nuchal translucency thickness by three-dimensional ultrasound.

OBJECTIVE: To investigate the feasibility and repeatability of nuchal translucency thickness measurement using three-dimensional ultrasound. METHODS: Forty consecutive women with uncomplicated singleton pregnancies attending for Down syndrome screening at 11-14 weeks' gestation were included in this prospective crossover trial. Nuchal translucency thickness was measured using both two-dimensional and three-dimensional ultrasound. In each case two three-dimensional volumes were recorded and then examined by using the technique of planar reformatted sections. The initial plane of the first volume always contained a clear image of the nuchal region ('sagittal volume'), whilst the initial plane of the second volume was selected randomly regardless of fetal position ('random volume'). The repeatability of nuchal translucency measurement was examined by constructing a scatter diagram of the difference between the measurements plotted against the mean of two readings. RESULTS: Nuchal translucency measurements could be repeated in 38/40 (95%) sagittal volumes and 24/40 (60%) random volumes. The mean difference between two-dimensional measurements and those obtained by reslicing of sagittal three-dimensional volumes was -0.097 mm (95% limits of agreement from -0.481 to 0.675) and 0.225 mm (95% limits of agreement from -0.369 to 0.819) when random volumes were examined. CONCLUSIONS: Reslicing of stored three-dimensional volumes can be used to replicate nuchal translucency measurements only when nuchal skin can also be clearly seen on two-dimensional ultrasound.

Cross-Over Studies↗

Outcome of pregnancy in chromosomally normal fetuses with increased nuchal translucency in the first trimester.

OBJECTIVES: To study the outcome of chromosomally normal pregnancies with increased nuchal translucency at the 10-14-week scan. DESIGN: Retrospective study of 1320 chromosomally normal singleton pregnancies with nuchal translucency of > or = 3.5 mm. In addition to fetal karyotyping these patients were managed with follow-up scans at 14-16 and 20-22 weeks, specialist fetal echocardiography and in selected cases by infection screening and further genetic testing. RESULTS: In the 1320 pregnancies there were 68 (5.15%) spontaneous abortions or intrauterine deaths, 18 (1.36%) neonatal and infant deaths and 154 (11.67%) terminations of pregnancy. In the 1080 (81.82%) survivors, 60 (5.56%) had abnormalities requiring medical or surgical treatment or leading to mental handicap. The chance of a livebirth with no defects in the group with nuchal translucency of 3.5-4.4 mm was 86%, for those with translucency of 4.5-5.4 mm it was 77%, for those with translucency of 5.5-6.4 mm it was 67%, and for those with translucency of > or = 6.5 mm it was 31%. CONCLUSIONS: Increased fetal nuchal translucency is associated with chromosomal abnormalities, many fetal defects and genetic syndromes. In the majority of cases a series of antenatal investigations, including fetal karyotyping, detailed scans, fetal echocardiography, as well as genetic testing and infection screening, that can be completed by 20 weeks of gestation would distinguish between the pregnancies destined to result in adverse outcome and those leading to the delivery of infants without major defects.

Female↗

Does acute hypoxia cause fetal arterial blood flow redistribution?

Chronic fetal hypoxia in fetal growth restriction due to impaired placentation is associated with centralization of blood flow to the vital organs, such as brain, heart and adrenal glands, in order to maintain oxygenation. There is a correlation between fetal hypoxemia and low impedance to blood flow in the middle cerebral artery. However, there is no association between abnormal flow velocity waveforms and fetal distress in an unselected population, and this reported case also suggests that Doppler ultrasound is of no value in identifying acute fetal distress.

Acute Disease↗

Placental villus morphology in relation to maternal hypoxia at high altitude.

Pregnancy at high altitude is associated with maternal hypoxaemic hypoxia with resultant intervillus blood hypoxia. Maternal haemoglobin concentration and blood gases were measured in pregnant women in two cities in Peru; Lima at sea level (n=18) and Cerro de Pasco at 4300 metres above sea level (n=12). Following delivery, placental sections from both groups were examined histomorphometrically using an image analysis system. Villus diameter, villus cross-sectional area, capillary diameter, capillary cross-sectional area and the percentage of villus cross-sectional area occupied by villus capillaries were calculated and parameters were compared between the two altitude groups. Maternal haemoglobin concentration and maternal blood pH were significantly higher, and maternal pO(2), pCO(2)and O(2)saturation were significantly lower in the high altitude group compared to those at sea level. The villus vessel area as a percentage of villus cross-sectional area and capillary diameter were significantly greater in the cases from the high altitude group and villus vessel area as a percentage of the villus cross-sectional area was significantly related to maternal pO(2)(r=-0.7, P=0.01), and maternal pCO(2)(r=0.7, P=0.02), but multiple regression analysis demonstrated that only pO(2)remained significantly independently associated with these villus histological findings (P=0.03). Placental terminal villi from term pregnancies at high altitude show different morphological features from pregnancies at sea level, and these changes are primarily related to maternal pO(2). The predominant morphological alteration is an increase in villus capillary diameter and therefore of the proportion of villus cross-sectional area occupied by capillary lumens.

Altitude↗

Maternal plasma glucose at high altitude.

OBJECTIVE: To compare plasma glucose in pregnant women living at very high altitude; pregnant women living at sea level; non-pregnant women living at very high altitude; and non-pregnant women living at sea level. DESIGN: Cross-sectional study. PARTICIPANTS: Ninety-four pregnant women attending for routine antenatal care at 8-42 weeks of gestation in Cerro de Pasco, Peru which is situated 4370 m above sea level; 122 pregnant women in Lima, which is at sea level; 22 non-pregnant women in Cerro de Pasco; and 31 non-pregnant women in Lima. METHODS: Plasma glucose concentrations were measured in samples obtained from the antecubital vein between 8 am and 10 am after an overnight period of fasting for at least 10 hours. RESULTS: Fasting plasma glucose was lower in women at high altitude than in those at sea level, and in both groups the level was lower in pregnant women than in non-pregnant controls. The body mass index was not significantly different between all four groups, and it did not have a significant independent contribution in explaining the variance in fasting plasma glucose. CONCLUSION: Women native at high altitude have lower plasma glucose concentrations before and during pregnancy than those at sea level.

Adult↗

Blood gases in pregnancy at sea level and at high altitude.

OBJECTIVE: 1. To measure blood gases and minute ventilation in healthy women with normal pregnancies, compare with non-pregnant women both at sea level and at high altitude; 2. to relate the results at altitude with duration of residence there. DESIGN: Cross-sectional study. SETTING: Antenatal clinics at sea level in Lima, Peru and at high altitude 4300m in Cerro de Pasco, Peru. POPULATION: A total of 304 normal pregnant women between 7 and 41 weeks of gestation were studied, including 112 who lived at sea level and 192 at high altitude (4300m). For comparison 38 non-pregnant women (19 at sea level and 19 at high altitude) were also studied. METHODS: Arterialised blood gases, haemoglobin, pulse oximetry and minute ventilation were measured once in each woman. MAIN OUTCOME MEASURES: PO2, PCO2, pH, haemoglobin, oxygen saturation, arterial oxygen content and minute ventilation and their relationship to gestation. RESULTS: PO2, PCO2, bicarbonate, base excess and oxygen saturation were lower in pregnancies at high altitude compared with sea level; pH, haemoglobin, arterial oxygen content and minute ventilation were higher. At high altitude oxygen saturation and haemoglobin decreased towards term resulting in a fall in arterial oxygen content at the end of pregnancy. Women whose family had lived at high altitude for at least three generations maintained their oxygenation throughout pregnancy better than women whose family had lived there for less than three generations. CONCLUSIONS: In pregnancy at high altitude maternal adaptation appeared adequate in the first trimester but declined towards term. However, maternal oxygenation was maintained in those whose family had lived longest at high altitude suggesting a beneficial adaptation to a hypoxic environment, occurring over generations.

Adult↗

Glucose metabolism in pregnancy at high altitude.

OBJECTIVE: To assess insulin sensitivity and beta-cell function associated with lower maternal fasting plasma glucose levels at high altitude compared with sea level. RESEARCH DESIGN AND METHODS: We studied 215 pregnant women at 8-42 weeks of gestation in Peru. The women were recruited from Cerro de Pasco, which is situated 4,370 m (14,340 feet) above sea level, and Lima, which is at sea level. We also examined 53 nonpregnant control subjects (22 in Cerro de Pasco and 31 in Lima). Fasting plasma glucose, insulin, C-peptide, and proinsulin concentrations were measured in samples obtained from the antecubital vein between 8:00 a.m. and 10:00 a.m. after an overnight period of fasting for 10-14 h Insulin resistance and beta-cell function were calculated using homeostasis model assessment. RESULTS: Fasting C-peptide levels and beta-cell function were similar, fasting concentrations of insulin and proinsulin were lower, and insulin sensitivity was higher at high altitude compared with sea level. CONCLUSIONS: Maternal fasting plasma glucose that is lower at high altitude than at sea level in the presence of similar insulin secretion is associated with higher peripheral insulin sensitivity. This may partly explain the lower birth weights at high altitudes.

Altitude↗

Transvaginal ultrasonography sonohysterography and operative hysteroscopy for the evaluation of abnormal uterine bleeding.

OBJECTIVE: To evaluate the diagnostic accuracy of transvaginal ultrasonography, sonohysterography and hysteroscopy in patients presenting with abnormal uterine bleeding. DESIGN: Prospective, blind, comparative study. SETTING: Outpatient clinic and day surgery unit of a district hospital specializing in operative hysteroscopy. PATIENTS: One hundred consecutive patients referred with abnormal uterine bleeding (AUB). INTERVENTIONS: Transvaginal ultrasonography and sonohysterography were performed in the outpatient clinic. Within 1 week, all patients underwent operative hysteroscopy. MAIN OUTCOME MEASURES: All diagnoses established by transvaginal ultrasonography, and sonohysterography were compared to the appearance of the cavity using hysteroscopy as well as the histological diagnosis from removed tissues. RESULTS: In 88 patients information suitable for analysis was obtained by all methods. The detection rate of focal intrauterine pathology using sonohysterography was (94.1%), but was significantly lower with transvaginal ultrasonography (23.5%). In about 75% of all cases none of the methods used was able to correctly detect endometrial hyperplasia. CONCLUSIONS: Sonohysterography was significantly better than transvaginal ultrasonography in detecting focal intrauterine pathology. Visual examination at operative hysteroscopy yielded no additional information to the detection or exclusion of focal lesions than was obtained at outpatient sonohysterography. All methods performed equally in assessing endometrial pathology. We conclude that sonohysterography may replace diagnostic hysteroscopy in many patients with AUB.

Adult↗

Fetal biometry at 4300 m compared to sea level in Peru.

OBJECTIVES: The aim of this study was to compare ultrasound fetal size at high altitude and sea level. METHODS: Three hundred and thirty-four women in Cerro de Pasco at 4300 m (14,100 ft) altitude and 278 women in Lima (sea level) were recruited to the study. Ultrasound fetal biometry was carried out between 14 and 42 weeks of gestation. Biparietal diameter, occipitofrontal diameter, abdominal circumference and femur length were measured and head circumference and estimated fetal weight were derived from these data. Two hundred and seventy-seven women (82.9%) in Cerro de Pasco and 216 (77.7%) in Lima had normal singleton pregnancies and certain menstrual dates. These women were selected for statistical analysis. Fractional polynomial regression analysis on gestational age was performed, controlling for maternal height and parity. RESULTS: Fetal biometry measurements were significantly smaller in Cerro de Pasco compared with Lima. When gestation bands were compared this effect was present from 25 to 29 weeks onwards, and was greater in the abdominal circumference than in the head circumference and femur length (ratios Cerro de Pasco: Lima, 0.96, 0.97 and 0.98, respectively). Estimated fetal weight was also significantly lower in Cerro de Pasco (ratio 0.88), as were birthweights (ratio 0.88). If the centiles derived from the Lima population were applied for Cerro de Pasco, 11.2% of all estimated fetal weights would be below the fifth centile, and 1.08% above the ninety-fifth. CONCLUSIONS: These data suggest that at high altitude, all fetal biometry measurements follow a lower trajectory than at sea level. Specific biometry charts should therefore be used for obstetric ultrasound at high altitude.

Altitude↗

[Ultrasound-guided transvaginal puncture of ovarian cysts].

Ultrasound-guided transvaginal aspiration of ovarian cysts offers a simple outpatient strategy for immediate pain relief and effective treatment but bears the risk of an iatrogenic spread of malignant cells. This study evaluated the cellular composition of the cyst fluids in a group of 26 sterility patients, in all of whom one or more ovarian cysts had been diagnosed and punctured. None of the patients had complications or evidence of malignant cells on cytological examination after the puncture. Only in one case dyskariotic cells were diagnosed causing an operative exploration that revealed a benign tumour. In 9 patients the ovarian cysts recurred and therefore 2 patients finally underwent an exploratory operation. In our opinion transvaginal ultrasound aspiration of functional cysts is an easy and safe procedure and may be undertaken in sterility patients in the context of specific criteria.

Adult↗

Air in the uterine cavity after embryo transfer.

OBJECTIVE: To examine the effect on the pregnancy rate (PR) caused by air bubbles loaded into the transfer catheter to bracket the embryo-containing medium. DESIGN: Prospective, randomized study. SETTING: One hundred ninety-six consecutive ETs in the Institute of Sterility Treatment. INTERVENTIONS: Air bubbles were loaded into the transfer catheter concomitantly with the medium in group I (n = 98), whereas in group II (n = 98) no air bubbles were used. RESULTS: The PR of group I equals that of group II. CONCLUSIONS: Bracketing the embryo-containing medium by air bubbles offers several advantages, especially the possibility of tracking the air on the ultrasound monitor to localize the embryos after the ET. For these reasons we recommend using the proven method.

Adult↗