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PubMed1996

Use of ankle brachial pressure index to predict cardiovascular events and death: a cohort study.

OBJECTIVE: To determine whether a low ankle brachial pressure index is associated with an increased risk of cardiovascular events and death, and whether the prediction of such events could be improved by including this index. DESIGN: Cohort study. SETTING: 11 practices in Edinburgh, Scotland. SUBJECTS: 1592 men and women aged 55-74 years selected at random from the age-sex registers of 11 general practices and followed up for 5 years. MAIN OUTCOME MEASURES: Incidence of fatal and non-fatal cardiovascular events and all cause mortality. RESULTS: At baseline 90 (5.7%) of subjects had an ankle brachial pressure index < or = 0.7, 288 (18.2%) had an index < or = 0.9, and 566 (35.6%) < or = 1.0. After five years subjects with an index < or = 0.9 at baseline had an increased risk of non-fatal myocardial infarction (relative risk 1.38, 95% confidence interval 0.88 to 2.16), stroke (1.98, 1.05 to 3.77), cardiovascular death (1.85, 1.15 to 2.97), and all cause mortality (1.58, 1.14 to 2.18) after adjustment for age, sex, coronary disease, and diabetes at baseline. The ability to predict subsequent events was greatly increased by combining the index with other risk factors--for example, hypertensive smokers with normal cholesterol concentrations had a positive predictive value of 25.0%, increasing to 43.8% in subjects with a low index and decreasing to 15.6% in those with a normal index. CONCLUSION: The ankle brachial pressure index is a good predictor of subsequent cardiovascular events, and improves on predictions by conventional risk factors alone. It is simple and accurate and could be included in routine screening of cardiovascular status.

Aged↗
PubMed1997

Longer term quality of life and outcome in stroke patients: is the Barthel index alone an adequate measure of outcome?

OBJECTIVES: To consider whether the Barthel Index alone provides sufficient information about the long term outcome of stroke. DESIGN: Cross sectional follow up study with a structured interview questionnaire and measures of impairment, disability, handicap, and general health. The scales used were the hospital anxiety and depression scale, mini mental state examination, Barthel index, modified Rankin scale, London handicap scale, Frenchay activities index, SF36, Nottingham health profile, life satisfaction index, and the caregiver strain index. SETTING: South east London. SUBJECTS: People, and their identified carers, resident in south east London in 1989-90 when they had their first in a life-time stroke aged under 75 years. INTERVENTIONS: Observational study. MAIN OUTCOME MEASURES: Comparison and correlation of the individual Barthel index scores with the scores on other outcome measures. RESULTS: One hundred and twenty three (42%) people were known to be alive, of whom 106 (86%) were interviewed. The median age was 71 years (range 34-79). The mean interval between the stroke and follow up was 4.9 years. The rank correlation coefficients between the Barthel and the different dimensions of the SF36 ranged from r = 0.217 (with the role emotional dimension) to r = 0.810 (with the physical functioning dimension); with the Nottingham health profile the range was r = -0.189 (with the sleep dimension, NS) to r = -0.840 (with the physical mobility dimension); with the hospital and anxiety scale depression component the coefficient was r = -0.563, with the life satisfaction index r = 0.361, with the London handicap scale r = 0.726 and with the Frenchay activities index r = 0.826. CONCLUSIONS: The place of the Barthel index as the standard outcome measure for populations of stroke patients is still justified for long term follow up, and may be a proxy for different outcome measures intended for the assessment of other domains.

Activities of Daily Living↗
PubMed2002

Alzheimer Disease: evaluation of a functional MR imaging index as a marker.

PURPOSE: To measure changes in functional synchrony in the hippocampus in patients with mild cognitive impairment (MCI) and Alzheimer disease (AD). MATERIALS AND METHODS: Three subject groups (nine cognitively healthy elderly control subjects, 10 patients with probable AD, and five subjects with MCI) underwent resting-state functional magnetic resonance (MR) imaging for measurement of functional synchrony in the hippocampus. Functional synchrony was defined and quantified as the mean of the cross-correlation coefficients of spontaneous low frequency (COSLOF) components between possible pairs of voxel time courses in a brain region, or the COSLOF index. The two-tailed Student t test was used to determine differences in the COSLOF index between the control group, the probable AD group, and the MCI group. An operating characteristic curve was calculated to graphically depict the tradeoff between sensitivity and specificity of the COSLOF index. RESULTS: Functional synchrony quantified with the COSLOF index was obtained in AD, MCI, and control subjects. COSLOF index values were significantly lower in AD patients than in control subjects (t = 4.32, P <.0012). For MCI subjects, COSLOF index values were significantly higher than those of AD patients (t = -2.4052, P <.047) but significantly lower than those of control subjects (t = 2.257, P <.043). The exponential-class curve significantly fits the relationship between the COSLOF index and the Mini-Mental Status Examination score (chi(2) = 20.4), indicating the rapid decrease in cognitive capacity below a threshold of the COSLOF index. CONCLUSION: Our results suggest that the COSLOF index could be used as a noninvasive quantitative marker for the preclinical stage of AD.

Aged↗
PubMed1988

Ventilation inhomogeneity during controlled ventilation. Which index should be used?

Six indexes for diagnosing uneven ventilation by tracer gas washout were studied. The indexes were lung clearance index, mixing ratio, Becklake index, multiple-breath alveolar mixing inefficiency, moment ratio, and pulmonary clearance delay, all of which increase with impaired pulmonary gas mixing. In model lung tests, indexes that compared the actual washout curve with a calculated ideal curve (mixing ratio, multiple-breath alveolar mixing inefficiency, and pulmonary clearance delay) were unaffected by changes in tidal volume and series dead space, whereas the others varied markedly. In both spontaneously breathing and mechanically ventilated patients all indexes showed a significant difference between smokers and nonsmokers (P less than 0.002), but the indexes were somewhat different in their assessment of different ventilatory patterns. However, the mean value for all indexes, with the exception of mixing ratio, was smallest with a fast insufflation followed by an end-inspiratory pause. Any of the indexes may be useful if its limitations are recognized, but mixing ratio, multiple-breath alveolar mixing inefficiency, and pulmonary clearance delay seem preferable, because they are not affected by changes in tidal volume and dead space fraction.

Adult↗
PubMed2006

Increased ambulatory arterial stiffness index is associated with target organ damage in primary hypertension.

Increased arterial stiffness has been shown to predict cardiovascular mortality in patients with primary hypertension. Asymptomatic organ damage is known to precede cardiovascular events. We investigated the relationship between a recently proposed index of stiffness derived from ambulatory blood pressure (BP) and target organ damage in 188 untreated patients with primary hypertension. Ambulatory arterial stiffness index was defined as 1 minus the regression slope of diastolic over systolic BP readings obtained from 24-hour recordings. Albuminuria was measured as the albumin:creatinine ratio, left ventricular mass index was assessed by echocardiography, and carotid abnormalities were evaluated by ultrasonography. The prevalence of microalbuminuria, left ventricular hypertrophy (LVH), and carotid abnormalities was 12%, 38%, and 19%, respectively. Ambulatory arterial stiffness index was positively related to age, triglycerides, office and 24-hour systolic BP, 24-hour pulse pressure, urinary albumin excretion, and carotid intima-media thickness. Patients with microalbuminuria, carotid abnormalities, or LVH showed higher ambulatory arterial stiffness index as compared with those without it. After adjusting for confounding factors, each SD increase in ambulatory arterial stiffness index entails an &2 times higher risk of microalbuminuria, carotid abnormalities, and LVH and doubles the risk of the occurrence of >or=1 sign of organ damage. Ambulatory arterial stiffness index is associated with organ damage in patients with primary hypertension. These data strengthen the role of this index as a marker of risk and help to explain the high cardiovascular mortality reported in patients with high ambulatory arterial stiffness index.

Adult↗
PubMedDate not supplied

A comparison of preference assessment instruments used in a clinical trial: responses to the visual analog scale from the EuroQol EQ-5D and the Health Utilities Index.

OBJECTIVES: To compare preference assessments that were made by using the EuroQol EQ-5D and the Health Utilities Index Mark II. SUBJECTS: 561 patients in a randomized trial of tirilazad mesylate for aneurysmal subarachnoid hemorrhage. MEASURES: Three preference assessments (a value score for the EuroQol instrument and value and utility scores for the Health Utilities Index) made three months after randomization. The averages for each of the three scores, stratified by clinical outcomes and attributes of the Health Utilities Index health status classification system, were compared. To evaluate potential sources of difference between the instruments, the authors estimated two alternative Health Utilities Index scoring rules that were based on patient responses to the EuroQol instrument. RESULTS: Patients' ratings of their current health made by using the 100-point visual analog scale from the EuroQol instrument were more similar to the utility scores for the Health Utilities Index than they were to the value scores for the Health Utilities Index. The biggest differences between the visual analog scores for the EuroQol instrument and the utility scores for the Health Utilities index were seen at higher levels of functioning. CONCLUSION: For states representing higher levels of functioning, differences were seen between patients' self-ratings obtained by using the EuroQol instrument and the patients' utility scores on the Health Utilities Index; for states representing lower levels of functioning, substantial agreement was observed between these two scores. Differences observed at the higher levels of functioning suggest that further research is needed to determine whether the Health Utility Index's assignment of a score of 1.0 to the reference state representing being healthy is appropriate.

Activities of Daily Living↗
PubMed2005

Modified calcaneal index: a new screening tool for osteoporosis based on plain radiographs of the calcaneum.

PURPOSES: To assess osteoporosis using plain radiography of the calcaneum by studying the performance characteristics of the modified calcaneal index through inter- and intra-observer agreement. To study the correlation of the modified calcaneal index to quantitative ultrasound of the calcaneus and bone mineral density (BMD) of the femoral neck and distal radius. METHODS: Lateral calcaneal radiographs of 252 women who participated in a clinical trial for osteoporosis were reviewed. The BMD of the hip and distal radius was measured and the calcanea were assessed using ultrasound. The calcaneal radiographs were graded by 3 clinicians according to a previously described 5-grade calcaneal index. A modified 3-grade calcaneal index was then developed. RESULTS: The highest scores of intra- and inter-observer reliability of the modified calcaneal index were 0.45 and 0.40, respectively, which were higher than those of the 5-grade calcaneal index. The correlation of the modified calcaneal index with other measures was significant (hip BMD, r=0.31; distal radius BMD, r=0.28; calcaneal speed of sound, r=0.20; broadband ultrasound attenuation, r=0.36) [p<0.005]. There were significant differences in hip BMD, distal radial BMD, calcaneal speed of sound, and broadband ultrasound attenuation between the 3 grades of the modified calcaneal index (Kruskal-Wallis 1-way ANOVA; p<0.0001). CONCLUSION: The modified calcaneal index can be used to measure bone structure and skeletal strength and is a suitable screening tool for osteoporosis in places where advanced approaches to bone-status assessment are not available.

Absorptiometry, Photon↗
PubMed2006

Improving the sensitivity of the hop index in patients with an ACL deficient knee by transforming the hop distance scores.

BACKGROUND: The one leg hop for distance is one of the most commonly employed functional tests utilized in the evaluation of the ACL deficient and reconstructed patient. While the reliability of the hop test scores has been well established, validity studies have revealed low sensitivity rates in detecting functional limitations using the hop index (the ratio or percentage of limb performance). However, the impact of the inherent limitations associated with the hop index have not been investigated to date. One specific limitation relates to the impact of the differences in the underlying hop distance scores. Therefore, this pilot study set out to determine: 1) the impact that between limb differences in hop distance has on the sensitivity of the hop index in detecting functional limitations and; 2) whether a logarithmic transformation of the underlying hop distance scores improves the sensitivity of the hop index. METHODS: A cross sectional design involving the evaluation of one leg hop for distance performance in a consecutive sample of 10 ACL deficient males with an isolated ACL tear awaiting reconstructive surgery and nine gender, age-matched controls. RESULTS: In the ACL deficient, the hop index was associated with the distance hopped on the non-injured limb (r = -0.66, p = 0.04) but not on the injured limb. Transformation (logarithmic) of the hop distance scores and re-calculation of the hop index using the transformed scores increased the sensitivity of the hop index in the detection of functional limitations from 20 to 60% and 50 to 70% using the normal limb symmetry reference norms of > or = 85% and 90% respectively. CONCLUSION: The distance hopped on the non-injured limb is a critical factor in detecting functional limitations using the hop index in patients with an ACL deficient knee. Logarithmic transformation of the hop distance scores minimizes the effect of the arithmetic differences between limbs however; the sensitivity of the hop index in detecting abnormal limb symmetry remains low.

Adult↗
PubMed2005

The association between propofol-induced loss of consciousness and the SNAP index.

The SNAP is a processed electroencephalogram monitor that uses an algorithm based on low- and high-frequency spectral components to derive a SNAP index. In this study we sought to determine the relationship of the SNAP index with loss of consciousness in subjects receiving a bolus of propofol. Unpremedicated subjects were randomized to receive 1 of 11 doses of IV propofol (0, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, or 2.4 mg/kg; n=20 per group). The SNAP index was recorded when the subject became unconscious (end-point) or at 160 s after the injection. Sixty-five percent of subjects achieved the end-point (defined as the time at which the subject dropped a weighted syringe). The 50% effective dose for propofol was 0.97 mg/kg (95% confidence interval [CI], 0.86-1.07 mg/kg). The median awake SNAP index was 92 (range 78-99) and did not differ between subjects who reached the end-point and those who did not. The end-point SNAP index decreased from baseline in the subjects who dropped the syringe to a median of 76 (range, 57-94) at doses > or =1.0 mg/kg but was not different among doses. The index was not different from baseline at 160 s in subjects who did not reach the end-point. Binary logistic regression models predicted a SNAP index 95% effective dose for loss of consciousness of 71 (95% CI, 63-74) and 19 (95% CI, 16-22) for changes in SNAP index from baseline. The areas under the receiver operator characteristic curves for these models were 0.837 and 0.864. The SNAP index correlated with propofol-induced loss of consciousness. It appears to be a useful indicator of loss of consciousness and should be further investigated as a monitor of anesthesia depth.

Adolescent↗
PubMed2001

Influence of index of individuality on false positives in repeated sampling from healthy individuals.

The index of individuality is defined as the ratio of the within-subject biological variation to the between-subject variation, i.e., the variation between the biological set-points. It has been disputed whether the index of individuality has influence on the usefulness of conventional population-based reference intervals. In this investigation we found that, as long as only a single sample is taken, for a certain change in an individual's set-point, the index of individuality has no influence on the usefulness of reference intervals. When two or more samples are taken into account, however, the outcome of the measurement is highly dependent on the index of individuality. For a low index, repeat measurement has only limited effect on the fraction of false-positive results, as the next result will be close to the first, but, when the index is high, the fraction of false-positive results will be reduced considerably through repeating the test. Moreover, the distribution of biological set-points for which the fraction of false-positive results originate is described and the influence of analytical imprecision is discussed. The calculations are performed for values of the index of individuality from 0 to 2.0 for the traditional 95% reference interval based on x +/- 2*s(total) (s(total) = total biological variation), and also for a decision limit (cut-off point) x +/- 3*s(total). The numbers are, of course, different, but the effects of the index of individuality are the same, independent of the chosen cut-off point. This concept is related to the clinical classification (diagnosis, prognosis, screening) and the difference from different principles of monitoring is discussed. Further, five examples are evaluated and aspects of index of individuality in relation to false-positive results are discussed.

Analysis of Variance↗
PubMed2004

Surveillance of mortality among atomic bomb survivors living in the United States using the National Death Index.

BACKGROUND: The National Death Index is a useful source to establish the death of an individual and to determine the cause of death. We identified deaths in atomic bomb survivors in the United States who were lost to follow-up through the National Death Index, and examined the completeness of mortality ascertainment in atomic bomb survivors in the US through the National Death Index. METHODS: Since 1977, biennial medical examinations of atomic bomb survivors in the US have been conducted. The 1,073 atomic bomb survivors in the US included 764 individuals who had medical examinations at least once in sixteen years from 1977 through 1993 and 309 individuals who reported atomic bomb survivorship to medical examination project themselves. Of the 1,073 survivors living in the US, 471 people who participated in the ninth health examinations of atomic bomb survivors living in the US in 1993 were removed, and two people among the remaining 602 individuals had no information about their birth dates and Social Security numbers. An investigation of those deceased between 1979 and 1993 was conducted among 600 of the atomic bomb survivors in the US. Death certificates for atomic bomb survivors in the US were requested from the National Death Index. A comparison was made between the information on the death certificates acquired through the National Death Index and the data ascertained from the medical examination project conducted from 1979 through 1993. RESULTS: Forty-nine death certificates were obtained using the National Death Index. By sex, the dominant cause of death in females was malignant neoplasm, accounting for 53%. In males, it was circulatory disease, accounting for 37%. The National Death Index and the medical examination project determined that 57 deaths had occurred between 1979 and 1993. The sensitivity and specificity of the National Death Index is 86% and 97% respectively. CONCLUSION: It is suggested that the National Death Index is useful to follow up mortality among atomic bomb survivors in the US.

Adult↗
PubMed1992

Sonography of renal transplants in dogs: the effect of acute tubular necrosis, cyclosporine nephrotoxicity, and acute rejection on resistive index and renal length.

Results of studies on the accuracy of the resistive index as a predictor of acute renal transplant rejection have varied widely. Clinical evaluations are limited by the inability to control the numerous coincidental factors that affect vascular resistance. We performed a controlled study in dogs to isolate the effects of acute tubular necrosis, cyclosporine toxicity, and acute rejection on the resistive index, and to compare them with a population of normal control subjects. By doing so, we hoped to identify the patterns of change in the resistive index over time and possibly explain the wide spectrum of resistive index data reported in the literature. Resistive index, a parameter calculated from relative systolic and diastolic velocity, indicates parenchymal resistance to perfusion. Since an increase in renal length also has been reported useful in predicting rejection, we studied changes in length in each of the isolated conditions. The normal control group (four dogs) had heterotopic autotransplantation with minimal cold ischemic time. The acute tubular necrosis group (six dogs) had heterotopic autotransplantation with 1 hr of warm ischemic time. The cyclosporine toxicity group (four dogs) was allowed approximately 3 months to heal from heterotopic autotransplantation. Very high (toxic) doses of cyclosporine were then administered. The acute rejection group (five dogs) had heterotopic allografting with minimal cold ischemic time. No medications were administered. In all groups, the abnormalities induced were confirmed by biopsy. Creatinine levels were also used to monitor cyclosporine toxicity. In the normal control and acute tubular necrosis groups, resistive index increased immediately after surgery, returning to baseline within 10 days. Renal length increased slightly in both groups, but the duration of increase was longer in the acute tubular necrosis group. No significant change in resistive index or renal length was seen in the cyclosporine toxicity group. In the acute rejection group, an initial decrease in resistive index during the mild to moderate phase was followed by a rapidly progressive increase with worsening rejection. Renal length increased progressively beginning immediately after surgery. Our study determined the patterns of change in resistance and renal length over time as caused by the isolated pathologic states. Our finding that vascular resistance decreased in mild to moderate acute rejection was unexpected, since almost all the literature reports resistive index elevation. This may explain some of the conflicting results obtained in Doppler investigations of rejection. Our results on renal length reinforce the positive clinical reports of its predictive value in rejection.

Animals↗
PubMed1986

Evaluation of patients with acute pancreatitis by means of chromogenic peptide substrate assays and the proenzyme functional inhibition index.

Using chromogenic peptide substrate assays the severity and clinical course were evaluated in 37 patients with acute pancreatitis. Retrospective clinical evaluation revealed that 20 patients had a severe disease, whereas 17 patients had mild acute pancreatitis. Seven of the patients with severe acute pancreatitis died. The proenzyme functional inhibition index (PFI index) is defined as the sum of deviations from the normal plasma pool values of plasma prekallikrein, functional kallikrein inhibition, plasminogen, antiplasmin, prothrombin and antithrombin III. Increased values are counted as positive, whereas reductions compared with the normal plasma pool values are recognized as negative. During the second day after admission the PFI index revealed significantly more negative values in severe cases than in patients with mild acute pancreatitis, -159 in severe case, -74 in mild cases (median values, P less than 0.05). The PFI index values were maintained strongly negative for the following 3 days in severe cases whereas the index was brought to positive values during the same period in patients with mild acute pancreatitis. The fatal cases revealed strongly negative PFI index values for the whole observation period. The patients with severe acute pancreatitis were earlier identified by means of the PFI index than by individual parameters also used for calculating the index. The results show that by means of the PFI index severity of acute pancreatitis can be recognized during early stages of the disease.

Acute Disease↗
PubMed1993

Influence of dietary buffer value index on the ruminal milieu of lactating dairy cows fed sorghum silage and grain.

The objective of this study was to evaluate the influence of dietary buffer value index on ruminal fluid pH, buffering capacity, and buffer value index in lactating cows. Three Holstein cows averaging 18 +/- 10 DIM were used in a 3 x 3 Latin square with 3-wk experimental periods. Diets contained grain:sorghum silage DM ratios of 50:50, 60:40, and 70:30. By analysis, these diets had buffer value indexes of -74, -41, and -7. The analyzed dietary buffer value index of the total diets was higher than the index that was calculated from the buffer value index of individual ingredients. Although milk fat content tended to be highest for milk from cows fed the 50:50 concentrate to forage diet and although milk protein production was highest for cows fed the 70:30 concentrate to forage diet, milk yield, 4% FCM, milk fat yield, protein content, and milk fat content were not significantly affected by dietary buffer value index. Dietary buffer equivalents were calculated to be 11% of total buffering equivalents available to the cow, and dietary acid equivalents were 15% of total acid production in the rumen. Compared with ruminal acid production and salivary buffering in the rumen, dietary acid and dietary buffer contributions to the acid-base balance of the cow are minor quantitatively. Ruminal fluid pH, hydrogen ion concentration, buffer value index, buffering capacity, and total VFA were not affected significantly by dietary buffer value index. Hence, dietary acid-base status alone is inadequate as a predictor of the need for buffers in the diet of lactating cows.

Animal Feed↗
PubMed2003

Influence of hemodialysis on echocardiographic Doppler indices of the left ventricle: changes in parameters of systolic and diastolic function and Tei index.

AIMS: Numbers of previous studies have evaluated the influence of dialysis-induced altered loading condition on Doppler-echocardiographic indices of left ventricle in patients with chronic renal failure. It has been suggested that most of Doppler-derived indices are preload-dependent. On the other hand, there are no studies that have evaluated the influence of hemodialysis on Tei index; a new Doppler-derived index obtained by isovolumetric contraction time plus isovolumetric relaxation time divided by ejection time. The aim of this study is to evaluate whether Tei index is also influenced by dialysis-induced altered loading condition as well as other Doppler-derived indices, and to assess the possibility that Tei index is also preload-dependent. PATIENTS AND METHODS: Thirty-two patients with chronic renal failure (21 men and 11 women, aged 48-93 years) on maintenance hemodialysis were evaluated for Doppler-derived indices before and after hemodialysis. We studied parameters of diastolic function (peak velocities of mitral inflow in early diastole (E) and late diastole from atrial filling (A), ratio of A to E (A/E), deceleration time (DT), and isovolumetric relaxation time (IRT)), parameters of systolic function (ejection time (ET), pre-ejection period (PEP), ratio of PEP to ET (PEP/ET), and isovolumetric contraction time (ICT)) and Tei index. RESULTS: Hemodialysis resulted in significant decreases in E, increase in A/E, prolongation of IRT, no change in A and DT; significant prolongation of ICT and PEP, shortening of ET, and increase in PEP/ET and a significant increase in Tei index (0.42 +/- 0.16 vs 0.51 +/- 0.16, p < 0.0001). When patients were subdivided into 2 groups based on weight loss after hemodialysis (> or = 1.5 kg and < 1.5 kg), only the group that lost > or = 1.5 kg had significant change in Tei index before and after hemodialysis (0.40 +/- 0.15 vs 0.52 +/- 0.17, p = 0.0002). CONCLUSION: This study demonstrates that not only most of Doppler-derived indices but also Tei index is affected by dialysis-induced altered loading condition and suggests that Tei index is possibly preload-dependent.

Aged↗
PubMed2004

Doppler sonography of renal obstruction: value of venous impedance index measurements.

OBJECTIVE: Arterial resistive index values have poor sensitivity and specificity for alterations in renal perfusion induced by collecting system obstruction. We aimed to determine whether the intrarenal venous impedance index values could be useful in evaluating renal parenchymal compliance in cases of obstruction and in differentiating acute obstruction from chronic cases. METHODS: Fifteen patients with acute renal colic having unilateral stone disease and another 15 patients having unilateral chronic obstruction due to various causes were evaluated sonographically. The diagnosis was confirmed either by computed tomography or intravenous urography in all cases. Fifteen subjects with normal kidneys were investigated as a control group. All patients were examined prospectively by conventional and Doppler sonography. The impedance indices and peak flow signals of the interlobar arteries and veins of both kidneys were calculated from spectral Doppler waveforms in all 3 groups. RESULTS: The mean venous impedance index on the acutely obstructed side was lower than the index on the unobstructed side: 0.25 +/- 0.07 and 0.53 +/- 0.3 (mean +/- SD), respectively (P = .005). The mean venous impedance index on the acutely obstructed side was less than the indices both on the chronically obstructed side and in the control subjects (P > .0001). In acute cases, the mean arterial resistive index on the obstructed side was higher than the index on the unobstructed side: 0.62 +/- 0.06 and 0.57 +/- 0.06, respectively (P = .001). No statistically significant difference was detected between other parameters evaluated for the test and control groups. CONCLUSIONS: Renal venous impedance index values may be helpful in evaluating renal hemodynamics in obstruction and in differentiating acute obstruction from chronic cases when used in conjunction with the arterial resistive index.

Adolescent↗
PubMed2003

[An epidemiological study on the index cases of severe acute respiratory syndrome occurred in different cities among Guangdong province].

OBJECTIVE: To analyze the epidemiological features of the index cases of severe acute respiratory syndrome (SARS) occurred in different cities in Guangdong province and to trace for the source of infection. METHODS: Standardized individual case inventory was adopted to conduct investigation on index cases and on persons who had close contact with index cases in Guangdong province. Data on the epidemiological characteristics, secondary cases and the links among index cases were analyzed. RESULTS: Between November 16, 2002 and April 16, 2003, there had been 13 index cases of SARS including 3 cadres, 3 farmers, 2 retirees, 2 workers and 1 shop attendant, reported from 13 cities in Guangdong province. Between November 2002 and January 2003, there had been 7 cities reported to have identified index cases of SARS with 6 of them being infected in their own cities and 1 imported from Guangzhou city. All of the cases had no close contacts to similar patients but 6 of them later caused 2nd or even 3rd generation cases of SARS. Most cases hit young people (7/13) with a sex ratio of 1:0.6. The fatality rate of index cases was high (4/13). CONCLUSION: No evidence showed that there was direct transmission among the index cases. Data regarding the geographical origin of those index cases led to the assumption that the infection had started in six cities of Pearl river delta region and the Hong Kong Special Administrative Region.

Adolescent↗
PubMedDate not supplied

[Diagnosis of middle cerebral artery spasm by determination of flow velocity and the Lindegaard index with transcranial color Doppler sonography].

BACKGROUND AND PURPOSE: Recent reports have demonstrated the high utility of transcranial color-coded duplex sonography (TCCS) in the diagnosis of advanced spasm of the middle cerebral artery, whereas its accuracy in the diagnosis of mild vasospasm is reported to be lower. Relation of blood flow velocity in the middle cerebral artery (MCA) to that in the extracranial internal carotid artery (VMCA/VICA index) is recommended as being helpful in the diagnosis of vasospasm (the so called Lindegaard Index). Nevertheless, the exact diagnostic value of this index using the TCCS method remains to be established. The purpose of this study is to estimate the accuracy of TCCS in the diagnosis of MCA vasospasm, as based on the VMCA/VICA index. MATERIAL AND METHODS: The VMCA/VICA index was calculated in 195 patients (285 middle cerebral arteries) who were scheduled for cerebral arteriography. The TCCS study and color-coded duplex sonography of the internal carotid arteries were performed immediately before arteriography. RESULTS: A mild grade of MCA spasm was diagnosed angiographically in 21, and moderate-to-severe spasm in 29 MCAs out of 285 successfully insonated arteries. Peak-systolic, mean and end-diastolic blood velocities were measured using transcranial color sonography in the MCA and related to the respective velocities in the ipsilateral extracranial internal carotid artery. Receiver-operating characteristic curves (ROC) were calculated for particular velocities and for the related VMCA/VICA indices. By comparison of the areas under the ROC curves it was shown that the use of the VMCA/VICA index does not improve the accuracy of TCCS in the diagnosis of advanced MCA spasm, whereas it improves accuracy in the diagnosis of mild vasospasm. In particular, accuracy can be improved by the use of the VMCA/VICA index based on the end-diastolic velocity. The optimal diagnostic threshold of the VMCA/VICA index was determined at 3.9. CONCLUSIONS: The use of VMCA/VICA index improves the accuracy of TCCS in the diagnosis of mild vasospasm of the middle cerebral artery.

Adult↗