Biomedical subjects

Yuchiao Chang

Publications and source records attributed to Yuchiao Chang.

42 records · Page 3Linked to original sources

PubMed2002

A utilization management intervention to reduce unnecessary testing in the coronary care unit.

BACKGROUND: There have been no studies of interventions to reduce test utilization in the coronary care unit. OBJECTIVE: To determine whether a 3-part intervention in a coronary care unit could decrease utilization without affecting clinical outcomes. METHODS: Practice guidelines for routine laboratory and chest radiographic testing were developed by a multidisciplinary team, using evidence-based recommendations when possible and expert opinion otherwise. These guidelines were incorporated into the computer admission orders for the coronary care unit at a large teaching hospital, and educational efforts were targeted at the house staff and nurses. Utilization during the 3-month intervention period was compared with utilization during the same 3 months in the prior year. The hospital's medical intensive care unit, which did not receive the specific intervention, provided control data. RESULTS: During the intervention period, there were significant reductions in utilization of all chemistry tests (from 7% to 40%). Reductions in ordering of complete blood counts, arterial blood gas tests, and chest radiographs were not statistically significant. After controlling for trends in the control intensive care unit, however, the reductions in arterial blood gas tests (P =.04) and chest radiographs (P<.001) became significant. The reductions in potassium, glucose, calcium, magnesium, and phosphorus testing, but not other chemistries, remained significant. The estimated reduction in expenditures for "routine" blood tests and chest radiographs was 17% (P<.001). There were no significant changes in length of stay, readmission to intensive care, hospital mortality, or ventilator days. CONCLUSION: The utilization management intervention was associated with significant reductions in test ordering without a measurable change in clinical outcomes.

Adult↗

PubMed2002

Higher frequency of high-grade rejections in cardiac allograft patients after Quilty B lesions or grade 2/4 rejections.

BACKGROUND: To better understand how different histologic patterns of allograft inflammation found on biopsies of human cardiac allografts progress to high-grade rejection, we undertook a statistical analysis of our institutional database to detect statistical patterns among different types of myocardial allograft inflammations found on sequential biopsies. METHODS: Biopsies were analyzed for statistical associations between high-grade rejections (International Society of Heart and Lung Transplantation [ISHLT] grade > or = 3A/4) and the type of cardiac allograft inflammation found on prior biopsies. Case cross-over and case control designs were used to compare the antecedent patterns of inflammation on biopsies with high-grade rejection compared to biopsies with low-grade rejection, all within the same subject. Quilty lesions were correlated with cyclosporine levels. RESULTS: Patients with Quilty B lesions or ISHLT grade 2/4 rejections show an increased risk for high-grade rejection on their next biopsies (Odds ratio 5.9 to 11.2). The presence of two pathological findings, especially Quilty B and grade 2/4 rejection, creates additional risk in excess of that found independently (Odds ratio >14). Quilty lesions are found only in cardiac allografts, and do not correlate with trough cyclosporine levels. CONCLUSIONS: The morphological patterns of several types of human cardiac allograft inflammation found on sequential protocol biopsies are not randomly associated. Patients with grade 2/4 rejections and Quilty B lesions show an increased risk for high-grade rejections on their next biopsies. Quilty B lesions, similar to ISHLT grade 2/4 rejections, may represent subclinical rejection. Both are more likely to progress to a high-grade rejection.

Biopsy↗

PubMed2002

Effects of removing gatekeeping on specialist utilization by children in a health maintenance organization.

BACKGROUND: The "gatekeeping" model of access to specialty care has been an essential managed care tool, intended to control costs of care and promote coordination between generalists and specialists. OBJECTIVE: To investigate the impact of removing gatekeeping on specialist utilization. METHODS: A capitated multispecialty group discontinued a gatekeeping system on April 1, 1998. We assessed the overall number and distribution of patient visits to primary care physicians and specialists and initial patient visits to specialists before and after the removal of gatekeeping. We performed focused analyses for specific specialties, children with chronic conditions, and children with specific diagnoses. RESULTS: Elimination of gatekeeping was not associated with changes in the mean number of visits to specialists (0.28 visits per 6 months before and after gatekeeping was removed) or the percentage of all child visits to specialists (11.6% vs 12.1%; 95% confidence interval, 11.3%-11.9% vs 11.8%-12.4%). The proportion of all specialist visits that were initial consultations increased after gatekeeping was removed, from 30.6% (95% CI, 29.4%-31.8%) to 34.8% (95% CI, 33.6%-36.1%). Visits to any specialist by children with chronic conditions increased from 18.6% (95% CI, 17.7%-19.1%) to 19.8% (95% CI, 19.0%-20.7%). New patient visits to specialists by children with chronic conditions as a proportion of all specialist visits increased from 28.1% (95% CI, 25.9%-30.2%) to 32.3% (95% CI, 30.1%-34.5%). CONCLUSIONS: Replacing a gatekeeping system with open access to all specialty physicians in a managed care organization resulted in minimal changes on the utilization of specialists. Visits to specialists by children with chronic conditions increased after the removal of gatekeeping.

Allergy and Immunology↗

PubMed2002

Prognostic histologic indicators of curatively resected hepatocellular carcinomas: a multi-institutional analysis of 425 patients with definition of a histologic prognostic index.

Despite growing information on the clinical behavior of hepatocellular carcinoma, the histologic features associated with survival are not well characterized. Clinical and pathologic data on 425 patients who underwent complete resection for hepatocellular carcinoma were reviewed. Six microscopic features, namely, microvascular invasion, nuclear pleomorphism, mitosis, tumor architecture, growth interface, and tumor necrosis, were examined. Independent predictors of survival were identified and combined into a simple prognostic index. By univariate analysis, microvascular invasion, seen in 51.3% of patients (p <0.001), nuclear grade 3, present in 42% of the cases (p <0.001), and mitosis (p <0.008) were significant predictors of poor survival. Hepatocellular carcinoma with a compact growth pattern had a better prognosis as compared with macrotrabecular (p = 0.014) and acinar (p = 0.051) patterns. By multiple regression analysis, only microvascular invasion (p <0.001) and nuclear grade 3 (p = 0.008) were independent predictors of poor survival. The predictive values of microvascular invasion and nuclear grade allowed the construction of a hepatocellular prognostic index (HPI) whereby HPI = (microvascular invasion status x 0.459) + (nuclear grade x 0.287), with microvascular invasion either absent (0) or present (1) and nuclear grade scored as 1, 2, or 3. Using a cut-off of 0.746 (corresponding to at least nuclear grade 2 with microvascular invasion), two groups could be segregated: fair prognosis (HPI < or = 0.746), with a 50% survival of 5.06 years, and poor prognosis (HPI >0.746) with a 50% survival of 2.71 years (p <0.001). HPI was more discriminating than Edmondson grade, with Edmondson II hepatocellular carcinomas dispersed in both fair and poor prognosis groups. Microvascular invasion and nuclear grade 3 emerge as strong prognostic indicators, and their combination provides adequate prognostic stratification. Practically, hepatocellular carcinoma can be stratified in two groups with regard to prognosis: 1) fair prognosis group (nuclear grade 1 with or without microvascular invasion and nuclear grade 2 without microvascular invasion), and 2) poor prognosis (nuclear grade 2 with microvascular invasion and nuclear grade 3 with or without microvascular invasion). The combination of these histologic parameters provides adequate prognostic stratification.

Adolescent↗

PubMed2002

The technical aspects of epidural steroid injections: a national survey.

UNLABELLED: Although epidural steroid injections (ESIs) are a common treatment for chronic pain conditions, it is not clear whether there is consensus on their technical aspects. The current literature suggests that variations in technical aspects may affect ESI outcomes. The goal of the survey was to help establish a standard frame of reference for the performance of ESIs. We analyzed survey results from 68 academic anesthesia programs and 28 private practices in the United States. The main finding in this survey is that there is no clear-cut consensus as to the ideal method to perform ESI. There is a wide variation among individual practices in almost every technical aspect of ESI. Private practices use significantly more fluoroscopy than academic centers. The large difference was found in the cervical region where 73% of private practices and only 39% of academic institutions polled perform the ESIs with fluoroscopic guidance (P = 0.005). A similar discrepancy was found in approaches to the epidural space after laminectomy where 61% of private practices, but only 15% of academic centers, use the transforaminal approach. The study results indicate that there is no consensus, and that there is a wide variation in current practices. IMPLICATIONS: A national survey of practices performing epidural steroid injections was conducted. The purpose was to establish whether consensus exists on technical aspects of this procedure. The study results indicate that there is no consensus, and that there is a wide variation in current practices.

Analgesia, Epidural↗

PubMed2002

Dynamic single-section CT demonstrates reduced cerebral blood flow in acute intracerebral hemorrhage.

Optimum blood pressure (BP) management in acute intracerebral hemorrhage (ICH) remains controversial. BP reduction may limit hematoma expansion, but may also exacerbate ischemia. Reduced regional cerebral blood flow (rCBF) has been reported in ICH. Its extent and precise pattern, however, remain uncertain. Dynamic single-section CT perfusion (CTP) is rapid, easily performed and offers superior spatial resolution to PET, SPECT and MRI. It may be the most applicable method for assessing the effects of BP management on rCBF in ICH. We sought to assess whether CTP can identify rCBF abnormalities in acute ICH in 5 patients with ICH who underwent CTP within 24 h of symptom onset. rCBF was measured in serially expanded 2-mm rings around the hematoma and compared with rCBF in the uninvolved hemisphere. Mean time to CTP was 9 h (range 3-23). Mean ICH volume was 25 ml (range 9-64). Perihematoma perfusion was reduced in all patients compared with contralateral hemisphere rCBF. rCBF reduction was most pronounced immediately adjacent to the hematoma (p < 0.05 at 2 mm, p = 0.084 at 4 mm, p > 0.2 at 6 and 8 mm). Perihematoma rCBF increased as a function of the distance from hematoma perimeter. Rate of rCBF increase over distance correlated with time from onset (p = 0.006). We conclude that CTP identifies a rim of reduced rCBF in ICH. A gradient of hypoperfusion appears to extend at least 4 mm beyond the hematoma edge and may be time dependent. Whether reduced CBF is associated with perihematoma ischemia requires additional study.

Aged↗