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Biomedical subjects

R S Brown

Publications and source records attributed to R S Brown.

At least 91 records · Page 5Linked to original sources
PubMed1998

Tranexamic acid and aprotinin reduce postoperative bleeding and transfusions during primary coronary revascularization.

UNLABELLED: We evaluated the blood conservation effects of tranexamic acid (TA) or aprotinin administered before and during cardiopulmonary bypass (CPB) in a prospective, randomized, double-blind study of 150 adult patients undergoing primary coronary artery bypass grafting surgery. Patients received either TA (2 g) or large-dose aprotinin (7 million KIU). Thirty additional untreated patients otherwise managed in a similar fashion were included from a recently completed study for comparison of outcomes. Demographic, medical, surgical, laboratory, mediastinal chest tube drainage (MCTD), transfusion, and outcome data were collected. Allogeneic blood product administration was tightly controlled. The demographic, medical, and surgical characteristics did not significantly differ between the two therapy groups. The median postoperative MCTD loss in the TA group did not significantly differ from that in the aprotinin-treated group (708 vs 600 mL). The percentage of patients that received no allogeneic blood products was 25% for the TA group and 27% for the aprotinin group (P = not significant). The median number of allogeneic blood products administered to the TA group (0 U) did not significantly differ from that administered to the aprotinin group (0 U). The percentage of patients with excessive MCTD (>1000 mL/24 h) did not significantly differ between groups (19% and 17%, respectively). In comparison, the control group had a significantly greater (P < 0.05) median MCTD (1020 mL), median allogeneic blood product exposure (4.5 U), and incidence of excessive MCTD (66%) and transfusion therapy (66%). These data help to support the use of pharmacologic methods to improve clinically relevant indicators of blood conservation for primary CPB procedures. Furthermore, the data show that TA is equivalent to aprotinin for blood conservation in patients at risk of excessive post-CPB bleeding and transfusion therapy. IMPLICATIONS: In a randomized, blind trial, we evaluated the effects of tranexamic acid or aprotinin on blood conservation after primary cardiopulmonary bypass surgery. Both drugs were equally effective in reducing blood loss, the incidence of transfusion, and the amount of blood products transfused compared with placebon.

Antifibrinolytic Agents↗
PubMed1998

Enterococcal bacteremia after transjugular intrahepatic portosystemic shunts (TIPS).

The objective of this study was to analyze a series of patients with Enterococcus faecium infection following transjugular intrahepatic portosystemic shunts (TIPS) in order to define the risk factors, outcome, and role of treatment including hepatic transplantation. This study is a case series from a tertiary referral center for liver transplantation. The medical records of four patients referred to one teaching hospital in San Francisco between 1990 and 1995 for evaluation or management of Enterococcal infection following TIPS were reviewed. A review of the microbiology records of all 314 patients who underwent TIPS at that institution and a MEDLINE search were performed to assess whether any other cases existed. The effect of therapy on survival was assessed, in particular, the repeated use of TIPS and prolonged courses of antibiotics. All four patients had thrombosis of their TIPS at the time of diagnosis of enterococcal bacteremia. All were treated with prolonged courses of intravenous antibiotics. One patient had echocardiographic evidence of subacute bacterial endocarditis with chronic aortic insufficiency. In all cases, liver transplantation was contraindicated in the acute setting because of uncontrolled endovascular infection. Two of four patients survived; these were the only two patients who had had a successful repeat TIPS. Enterococcal bacteremia is a rare complication following TIPS but carries a high mortality. It usually occurs in the setting of technically difficult TIPS with shunt thrombosis. Management should be focused on long term antibiotics and attempts at reestablishment of portal decompression with another TIPS. Liver transplantation should not be considered until the infection is cleared. Prophylaxis for Enterococcus species should be considered in technically difficult or unsuccessful TIPS.

Adult↗
PubMed1998

Effect of insulin on uptake of FDG by experimental mammary carcinoma in diabetic rats.

PURPOSE: To determine whether insulin improves tumor uptake of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) in diabetic rats with mammary carcinoma. MATERIALS AND METHODS: Rats were inoculated subcutaneously with mammary carcinoma cells. Four weeks later, diabetes was established with streptozocin while controls were given saline. Two weeks later, after overnight fasting, 12 diabetic and 11 control rats received saline and five diabetic rats received insulin 60 minutes before FDG injection (100 microCi [3.7 MBq]). Three diabetic rats received insulin 30 minutes before FDG injection. One hour after FDG injection (i.e., at sacrifice), F-18 activity in tumor and normal tissues was measured. RESULTS: Insulin significantly reduced blood glucose levels in diabetic rats at sacrifice. Tumor FDG uptake, which significantly declined with untreated diabetes (P < .005 vs controls), was not significantly different between insulin-treated and untreated diabetic rats. Insulin significantly improved tumor/lung and tumor/liver uptake ratios in diabetes (P < .005), although the tumor/muscle uptake ratio significantly decreased to 40% of the diabetic value with insulin (P < .005). CONCLUSION: Diabetes markedly impairs tumor targeting with FDG. In diabetic patients, the judicious use of insulin may improve tumor/nontumor uptake ratios in specific organs such as the liver or lung, although insulin consistently reduces tumor/muscle uptake ratios.

Animals↗
PubMed1998

Synthetic hair braid extension artifacts in panoramic radiographs.

The authors present two case reports that illustrate synthetic hair braid extension artifacts in panoramic radiographs. They found that hairstyles using synthetic hair braid extensions created radiopaque patterns that varied according to hairstyles. They discuss how these hair extensions may affect panoramic radiographs and the importance of determining whether patients are wearing synthetic hair braid extensions.

Adult↗
PubMed1997

Outcomes of stroke patients in Medicare fee for service and managed care.

CONTEXT: Increasing numbers of Medicare beneficiaries have been enrolling in health maintenance organizations (HMOs) because HMO participation reduces out-of-pocket expenses, and the federal government views HMOs as a way to contain Medicare costs. However, results comparing outcomes and quality of care in HMOs vs fee for service (FFS) have been mixed, and outcomes after stroke have not been adequately assessed. OBJECTIVE: To compare discharge destinations and survival rates following stroke in Medicare HMOs with similar FFS settings. DESIGN: An observational study for 2 groups evaluating stroke patients' discharge destinations and survival times from the date of hospital admission. SETTING: A total of 19 HMOs were selected from 12 states. The FFS sample was drawn from the same geographic areas. PATIENTS: The sample included 402 HMO patients from 71 hospitals and 408 FFS patients from 60 hospitals. PROCESS AND OUTCOME MEASURES: Data were abstracted from medical records on demographics, clinical characteristics of stroke, comorbid illnesses, and discharge destinations following hospitalization. Data on survival were obtained from Medicare files and included 25 to 37 months of follow-up (median, 30.4 months, HMO; 31.1 months, FFS) from the date of hospital admission. RESULTS: There were 109 patients who died during the hospitalization (49 HMO, 12.2%; 60 FFS, 14.7%), and a total of 410 patients had died by the end of follow-up (191 HMO, 47.5%; 219 FFS, 53.7%). Approximately one fourth of both groups had do-not-resuscitate orders (HMO, 25.4%; FFS, 27.9%; P=.68). After controlling for age, marital status, and characteristics of dependency at discharge, HMO patients were more likely than FFS patients to be sent to nursing homes (HMO, 41.8%; FFS, 27.9%; P=.001) and less likely to be discharged to rehabilitation hospitals or units (HMO, 16.2%; FFS, 23.4%; P=.03). At follow-up, no significant differences in relative risk of dying were found between HMO and FFS groups (relative risk, 0.96; 95% confidence interval, 0.73-1.26; P=.77). CONCLUSIONS: Patients in Medicare HMOs who experience strokes are more likely to be discharged to nursing homes and less likely to go to rehabilitation facilities following the acute event. However, they have similar survival patterns compared with comparable patients in FFS settings after adjusting for other factors.

Aged↗
PubMed1997

The impact of surgical complications after liver transplantation on resource utilization.

OBJECTIVE: To evaluate the impact of surgical complications on length of stay and hospital charges after liver transplantation. DESIGN: A retrospective economic evaluation of the outcomes during initial hospitalization after liver transplantation. SETTING: University hospital treating referred patients. PATIENTS: The study population was 109 patients undergoing 111 liver transplantations during fiscal year 1993. MAIN OUTCOME MEASURES: Hospital charges and length of stay during the initial hospitalization after liver transplantation. Multivariate regression methods were used to analyze the impact of surgical complications on costs. RESULTS: Of the 111 transplantations, 30 (27%) had a surgical complication that required a return to the operating room during the initial hospitalization. The effect of a surgical complication was to increase the mean hospital charges (excluding physician charges) from $150,092 to $347,728 (difference of mean, $197,636; confidence interval of difference, $114,153 to $319,326). The median length of stay was 16 days for patients without complications and 45 days for those with complications. Univariate and multivariate models suggested that surgical complications had the greatest effect on length of stay and hospital charges among the factors studied. Complications tended to occur more frequently among patients with United Network for Organ Sharing (UNOS) status 1 (42% vs 22%), but this did not reach statistical significance (P = .09). CONCLUSIONS: Surgical complications after liver transplantation have a marked impact on the cost of the procedure. The magnitude of this effect is greater than that of UNOS status, presence of rejection, or other demographic or clinical factors studied. Complications tend to occur in the most ill patients. Identifying strategies to reduce the risk of complications, particularly in patients with UNOS status 1, likely can reduce the cost of transplantation.

Adolescent↗
PubMed1997

Intratumoral microdistribution of [131I]MB-1 in patients with B-cell lymphoma following radioimmunotherapy.

Intratumoral microdistribution of radiolabeled anti-CD37 murine monoclonal antibody, [131I]MB-1, in lymph nodes from five patients with non-Hodgkin's B-cell lymphoma following radioimmunotherapy were evaluated by microautoradiography and image analysis of macroautoradiographs. Microdistribution of radioactivity was highly heterogeneous: silver grain counts varied from 28-70 to 8-10 per 400 X field, and the coefficients of variations calculated by image analysis ranged between 42.5 and 79.3%. Variable radiation doses delivered could have contributed to the limited durability of tumor regression.

Antibodies, Monoclonal↗
PubMed1997

"Scalded mouth syndrome" caused by angiotensin converting enzyme inhibitors: two case reports.

Two cases of "scalded mouth syndrome" are presented and discussed. This condition is a rare side effect of angiotensin converting enzyme inhibitors. Angiotensin converting enzyme inhibitors are known to cause several other oral and extra-oral side effects. In scalded mouth syndrome, the patient's complaints concern a burning pain of the oral soft tissues. There are no clinical findings.

Aged↗
PubMed1997

Routine skin cleansing with povidone-iodine is not a common cause of transient neonatal hypothyroidism in North America: a prospective controlled study.

A high incidence of transient neonatal hypothyroidism has been observed in premature infants after routine skin cleansing with iodine. Because these reports have been predominantly from Europe, a borderline, iodine-deficient area, we wished to determine whether this was also true in North America, an iodine-sufficient area. A prospective, controlled study was performed in premature babies < or = 36 weeks gestation admitted to a neonatal intensive care nursery. Thyroxine (T4) and thyrotropin (TSH) were measured at day 1, days 4 to 6, and 10 to 12 after skin preparation with iodine or with a noniodine-containing antiseptic solution (chlorhexidine) that served as control. If repeat cleansing was required, this sequence was repeated. Urinary iodine was quantitated on days 1 to 3 to estimate iodine exposure. There was no difference in the mean T4 concentration at any of the time points evaluated nor in the incidence of transient hypothyroidism between the iodine-exposed (2/17) and control babies (0/14) despite urinary iodine excretion up to 88 times the control value. Unexpectedly 5 iodine-exposed but 0 control babies developed severe hypothyroxinemia (T4 < 40 nmol/L), compatible with the sick euthyroid syndrome; one of them died. We conclude that, unlike in Europe, transient hypothyroidism is not a common sequela of routine skin cleansing with iodine in premature newborn infants in North America. This difference in incidence may be due to prior iodine status. Whether excessive iodine absorption in premature infants is associated with thyroid-independent toxic effects remains to be clarified.

Anti-Infective Agents, Local↗
PubMed1997

Tranexamic acid is effective in decreasing postoperative bleeding and transfusions in primary coronary artery bypass operations: a double-blind, randomized, placebo-controlled trial.

UNLABELLED: We evaluated the effects of tranexamic acid (TA) administered before and after cardiopulmonary bypass (CPB) in a prospective, randomized, placebo-controlled, double-blind study of adult patients undergoing primary coronary artery bypass grafting surgery. Patients received placebo (n = 30) or TA 15 mg/kg before CPB, followed by a TA infusion of 1 mg x kg(-1) x h(-1) for 5 h (n = 30) or TA 15 mg/kg after CPB, followed by a TA infusion of 1 mg x kg(-1) x h(-1) for 5 h (n = 30). Demographic, medical, surgical, laboratory, mediastinal chest tube drainage (MCTD), hemoglobin loss, transfusion, and outcome data were collected. Allogenic blood product administration was tightly controlled. The demographic, medical, and surgical characteristics were similar in all three groups. The median postoperative MCTD and hemoglobin loss in the pre-CPB TA group (710 mL, 8.6 g) was significantly less (P < 0.001) compared with the control (1202 mL, 44.2 g) and post-CPB TA groups (1020 mL, 23.4 g). The percentage of patients who received no allogenic blood products was 27% for the pre-CPB TA group and 33% for the post-CPB TA group (not significant). These percentages were significantly lower than those in the placebo group (66%, P < 0.001). The median number of allogenic blood products administered to the pre-CPB TA group (0 units) was significantly less compared with the control group (4.5 units). The thromboelastogram and fibrinogen split product levels in the pre-CPB TA group indicated better platelet function and less activation of the fibrinolytic system compared with the other two groups (P < 0.05). There were no intergroup differences in reoperation, myocardial infarction, stroke, infections, or death. These data support the use of pre-CPB TA to decrease patient exposure to postcardiopulmonary bypass allogenic blood products. IMPLICATIONS: In this randomized, placebo-controlled trial, we investigated the efficacy of tranexamic acid to decrease bleeding and blood transfusions after open-heart operations. Tranexamic acid administered before and during the operation was effective in decreasing both bleeding and transfusions. When tranexamic acid was administered immediately after the operation, it had a minor beneficial effect.

Aged↗
PubMed1997

Transjugular intrahepatic portosystemic shunt as a form of treatment for portal hypertension: indications and contraindications.

The TIPS clearly has had a major impact on the treatment of complications of portal hypertension in the cirrhotic patient. Currently, TIPS is performed in community hospitals as well as university centers in the United States. While the shunt is placed under local anesthesia in a nonoperative fashion, it must be remembered that it does function as a highly effective side-to-side shunt with its attendant complications including hepatic encephalopathy and occasional liver failure. Early reports of clinical and hemodynamic results after TIPS have clearly demonstrated it to be an effective bridge to liver transplantation. Nonetheless, transplantation candidates who experience their initial episode of variceal hemorrhage still should be managed with sclerotherapy or variceal band ligation. However, if bleeding recurs during a course of treatment or cannot be acutely controlled, TIPS has proved invaluable in stabilizing patients prior to liver transplantation. Refractory variceal bleeding in Child's class C patients, in whom the perioperative mortality associated with surgical shunts is high, is also reasonable indication for TIPS. Potential, but less well-proved indications for TIPS include refractory ascites, hepatic hydrothorax, and the Budd-Chiari syndrome. Refractory variceal hemorrhage in Child's class A or B patients, bleeding from portal hypertensive gastropathy, and HRS represent possible, but unproved, indications. Preoperative reduction in portal hypertension prior to liver transplantation does not appear to represent an appropriate indication for TIPS. In spite of the wide acceptance of TIPS, it will be important to continue to study its indications and its complications so that it can be optimally used in the treatment of patients with portal hypertension.

Algorithms↗
PubMed1996

Outcome of patients with renal insufficiency undergoing liver or liver-kidney transplantation.

Renal insufficiency (RI) is a common finding with end-stage liver disease. RI is generally not regarded as a contraindication to liver transplantation. However, the impact of RI on outcome following transplantation and the role of combined liver-kidney transplant are not well understood. The effect of RI on patients with fulminant hepatic failure (FHF) or chronic liver disease (cirrhosis) was investigated using the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Liver Transplantation Database. Patients were analyzed based on the presence of RI, defined as creatinine >1.6 mg/dl, or on dialysis. Patients undergoing liver-kidney transplantation were analyzed separately. For patients with FHF, the RI group had a lower patient survival rate at 1 year (50% vs. 83%, P=0.04) and tended to have a lower graft survival rate (50% vs. 71%). Stay in the intensive care unit (ICU) was prolonged in the RI group but hospital stay was not. Among patients with cirrhosis, RI did not affect patient survival, except for patients on dialysis or those with liver-kidney transplants. One-year patient and graft survival rates were 65% and 60% for the dialysis group, 74% and 70% for the liver-kidney transplant group, 89% and 86% for RI patients not on dialysis, and 89 and 84% for non-RI patients. ICU and hospital stays were prolonged for all of the RI groups compared with the non-RI patients. Patients with RI had higher rates of posttransplant dialysis; however, the differences tended to equalize after 4 weeks. We conclude that RI in FHF and RI requiring dialysis or liver-kidney transplantation in cirrhosis predict lower posttransplant patient and graft survival rates. Patients with RI have longer hospital and ICU stays and an increased need for dialysis, which likely increases the cost of transplantation. Whether liver-kidney transplantation improves outcome and thus represents an appropriate use of cadaver kidneys requires further study.

Adult↗
PubMed1996

Incidence and significance of Aspergillus cultures following liver and kidney transplantation.

Aspergillus infection is a rare but devastating complication following solid organ transplantation, with mortality rates that approach 100%. Aspergillus species (sp) are also ubiquitous in our environment and may contaminate culture plates. To determine the significance of positive Aspergillus cultures, we analyzed all positive cultures from the liver and kidney transplant services at our center for the treatments used and clinical outcomes. Aspergillus sp. were cultured from 4.5% of liver and 2.2% of kidney transplant recipients. A. fumigatus was the most common isolate, followed by A. niger and A. flavus. The lung was the most common site of positive cultures. Body fluids (ascites, pleural fluid) were common sources of positive cultures but were never associated with clinical disease. Positive brain biopsies occurred in 10% of patients. Analysis of risk factors for significant infection revealed that cultures with >2 colonies or more than one site of infection were predictive of significant infection and portended a poor prognosis even with aggressive therapy. Two or fewer colonies from a single site likely represented contamination and may be followed with repeat cultures. The high mortality rate associated with Aspergillus sp. infections in transplant recipients highlights the need for better anti-fungal prophylaxis and treatment.

Adult↗
PubMed1996

Do school-based health centers improve adolescents' access to health care, health status, and risk-taking behavior?

PURPOSE: The purpose of this investigation was to assess the School-Based Adolescent Health Care Program, which provided comprehensive health-related services in 24 school-based health centers. METHODS: The outcomes evaluation compared a cohort of students attending 19 participating schools and a national sample of urban youths, using logit models to control for observed differences between the two groups of youths. Outcome measures included self-reports concerning health center utilization, use of other health care providers, knowledge of key health facts, substance use, sexual activity, contraceptive use, pregnancies and births, and health status. RESULTS: The health centers increased students' access to health care and improved their health knowledge. However, the estimated impacts on health status and risky behaviors were inconsistent, and most were small and not statistically significant. CONCLUSIONS: School-based health centers can increase students' health knowledge and access to health-related services, but more intensive or different services are needed if they are to significantly reduce risk-taking behaviors.

Adolescent↗