PubMed Health⌕ Search

Biomedical subjects

H Doyle

Publications and source records attributed to H Doyle.

At least 19 recordsLinked to original sources
PubMed2001

Applying split-thickness skin grafts: a step-by-step clinical guide and nursing implications.

Wounds in the lower extremities represent a complex medical dilemma and a significant financial burden on the healthcare system. Often, skin grafts and flaps must be incorporated into the treatment of complex defects. Wound management has developed from a multidisciplinary to a collaborative forum, blurring treatment lines among the specialties. Various clinicians and specialists are playing an increasingly larger role in the healing algorithm of wounds in the lower extremities, including the application of skin grafts. This allows the plastic surgeon to deal with the more complex free flaps and microscopic surgical procedures. A patient's status following skin grafting can be an issue in many nursing care environments. This paper provides a pictorial review of a reliable split-thickness skin graft technique that fosters imbibition and inosculation. The points relevant to nursing care include nursing implications (for the graft and donor site), complications, and what to expect in patients who have undergone the procedure.

Bandages↗
PubMed1999

Medical knowledge and the intractable patient: the case of chronic low back pain.

Chronic low back pain (CLBP) is endemic in Western societies, and while a good deal of attention has been paid to the lay experience of such pain, much less sociological attention has been paid to the way in which medical ideas about it have been formulated. This paper takes the latter course, tracing the development of clinical notions about the relationship between pathological signs and expressed symptoms from the 1820's to the 1930's, and then placing these developments in the context of postwar notions of 'somatization'. We point to the extent to which the disparity between expressed symptoms, pathological signs and perceived disability in CLBP has led to the moral character of the sufferer forming a constant subtext to medical discourse about the condition. We also note the extent to which medical ideas themselves have been constructed in intimate linkage with socio-legal questions of compensation and worker's insurance.

Attitude of Health Personnel↗
PubMed1998

Orthotopic liver transplantation in high-risk patients: risk factors associated with mortality and infectious morbidity.

BACKGROUND: One of the most controversial areas in patient selection and donor allocation is the high-risk patient. Risk factors for mortality and major infectious morbidity were prospectively analyzed in consecutive United States veterans undergoing liver transplantation under primary tacrolimus-based immunosuppression. METHODS: Twenty-eight pre-liver transplant, operative, and posttransplant risk factors were examined univariately and multivariately in 140 consecutive liver transplants in 130 veterans (98% male; mean age, 47.3 years). RESULTS: Eighty-two percent of the patients had postnecrotic cirrhosis due to viral hepatitis or ethanol (20% ethanol alone), and only 12% had cholestatic liver disease. Ninety-eight percent of the patients were hospitalized at the time of transplantation (66% United Network for Organ Sharing [UNOS] 2, 32% UNOS 1). Major bacterial infection, posttransplant dialysis, additional immunosuppression, readmission to intensive care unit (P=0.0001 for all), major fungal infection, posttransplant abdominal surgery, posttransplant intensive care unit stay length of stay (P<0.005 for all), donor age, pretransplant dialysis, and creatinine (P<0.05 for all) were significantly associated with mortality by univariate analysis. Underlying liver disease, cytomegalovirus infection and disease, portal vein thrombosis, UNOS status, Childs-Pugh score, patient age, pretransplant bilirubin, ischemia time, and operative blood loss were not significant predictors of mortality. Patients with hepatitis C (HCV) and recurrent HCV had a trend towards higher mortality (P=0.18). By multivariate analysis, donor age, any major infection, additional immunosuppression, posttransplant dialysis, and subsequent transplantation were significant independent predictors of mortality (P<0.05). Major infectious morbidity was associated with HCV recurrence (P=0.003), posttransplant dialysis (P=0.0001), pretransplant creatinine, donor age, median blood loss, intensive care unit length of stay, additional immunosuppression, and biopsy-proven rejection (P<0.05 for all). By multivariate analysis, intensive care unit length of stay and additional immunosuppression were significant independent predictors of infectious morbidity (P<0.03). HCV recurrence was of borderline significance (P=0.07). CONCLUSIONS: Biologic and physiologic parameters appear to be more powerful predictors of mortality and morbidity after liver transplantation. Both donor and recipient variables need to be considered for early and late outcome analysis and risk assessment modeling.

Adult↗
PubMed1998

[Hilar and peripheral cholangiocarcinomas].

Cholangiocarcinoma is the most frequent malignant neoplasm of the bile ducts. It continues to be a diagnostic and therapeutic challenge because of its form of growth and intimate relation with hepatic hilus structures. While cholangiocarcinomas situated distal to the biliary confluence have well-defined characteristics and treatment, cholangiocarcinomas situated in or proximal to the biliary confluence are problematic. A study was made of the so-called intrahepatic cholangiocarcinomas by establishing two types, peripheral and hilar. Their features and therapeutic options are analyzed and published results are reviewed.

Age Factors↗
PubMed1997

Invasive fungal infections in liver transplant recipients receiving tacrolimus as the primary immunosuppressive agent.

Invasive fungal infections and their risk factors were prospectively assessed in 130 consecutive liver transplant recipients receiving tacrolimus as the primary immunosuppressive agent. Eleven percent (14) of the 130 patients had 17 episodes of invasive fungal infections. These included candidiasis (5%; 6 patients), cryptococcosis (5%; 6), aspergillosis (3%; 4), and chromomycosis (1%; 1). An elevated pretransplantation creatinine level, requirement of dialysis (pretransplantation or posttransplantation), duration of intensive care unit stay after transplantation surgery, and antibiotic use (other than for prophylaxis) within 4 weeks of transplantation were significant risk factors for fungal infections occurring within 100 days of transplantation. For fungal infections occurring after 100 days, persistence of renal dysfunction (serum creatinine level of >2.5 mg/dL at 3 months), dialysis, and histopathologically documented recurrence of hepatitis C virus hepatitis were significant risk factors. Mortality was significantly higher among patients with fungal infections than among all other patients (57% vs. 15%; P = .0009). Our study identified specific risk factors for invasive fungal infections in liver transplant recipients receiving tacrolimus; strategies to prevent fungal infections or to initiate early antifungal therapy might be most effectively targeted at these patients.

Adult↗
PubMed1996

Computer-guided randomized concentration-controlled trials of tacrolimus in autoimmunity: multiple sclerosis and primary biliary cirrhosis.

A randomized concentration-controlled clinical trial (RCCCT) is a trial design in which patients are randomized to predefined blood drug concentrations (low, medium, high). If the concentration ranges are sufficiently separated, this study design can reveal important blood concentration-response relations. Tacrolimus is a potent yet "infant" immunosuppressant for the treatment and prevention of graft rejection and has been shown to exhibit significant clinical activity in some immune-mediated disorders. A tacrolimus artificial intelligence modeling system (AIMS) was used to guide patient dosing to achieve target concentrations specified by the study protocols. In the Multiple Sclerosis study group, we were able to define a concentration range (0.3-0.7 ng/ml) that appeared to show efficacy and minimal tacrolimus toxicity. Patients randomized to the high zone (0.6-1.2 ng/ml) in the Primary Biliary Cirrhosis study group showed significant reduction (approximately 50%) in surrogate efficacy markers [aspartate aminotransferase (SGOT), alanine aminotransferase (SGPT)] compared with patients in the low zone (0.1-0.6 ng/ml). Therefore the RCCCT allowed the detection and delineation of clinically significant concentration-response relations in an ethical and efficient manner.

Artificial Intelligence↗
PubMed1994

Single-center experience with primary orthotopic liver transplantation with FK 506 immunosuppression.

OBJECTIVE: The efficacy for primary orthotopic liver transplantation of a new immunosuppressive agent, FK 506 (tacrolimus, Prograf, Fujisawa USA, Deerfield, IL), was determined. SUMMARY BACKGROUND DATA: After 3 years of preclinical research, a clinical trial of FK 506 for orthotopic liver transplantation was begun in February 1989, first as a rescue therapy for patients with intractable rejection with conventional immunosuppression, then as a primary drug. METHODS: Between August 1989 and December 1993, 1391 recipients (1188 adult and 203 pediatric) of primary liver allografts were treated with FK 506 from the outset. Results from these patients were analyzed and compared with those of 1212 historical control patients (971 adult and 241 pediatric) given cyclosporine-based immunosuppression. RESULTS: Actuarial survival at 4 years was 86.2% with FK 506 versus 65.5% with cyclosporine in the pediatric patients (p < 0.0000) and 71.4% versus 65.5% in the adults (p < 0.0005). The need for retransplantation was reduced significantly for FK 506 patients. Four-year graft survival was 77.0% with FK 506 versus 48.4% with cyclosporine in the pediatric patients (p < 0.0000), and 61.9% with FK 506 versus 51.4% with cyclosporine in the adult recipients (p < 0.0000). Regression analysis revealed that reduction in mortality or graft loss from uncontrollable rejection, sepsis, technical failure, and recurrent original liver disease were responsible for the improved results with FK 506 therapy. CONCLUSIONS: FK 506 is a potent and superior immunosuppressive agent for orthotopic liver transplantation.

Actuarial Analysis↗
PubMed1994

Follow-up study of young attenders at an alcohol unit.

A follow-up study of all under 21 year olds satisfying DSM-III-R criteria for alcohol dependence treated as in-patients at an alcohol treatment unit over a 10-year period was conducted. A total of 52 individuals were identified and of these 80% (44) were traced. The mean period of follow-up was just over 4 years. A poor outcome (no abstinence or controlled drinking for the past 6 months) was adjudged in 61.4% (27) of the cases. This was associated with indicators of early personality difficulties and unsatisfactory schooling experiences. There was considerable concurrent illicit drug use associated with continuing problem drinking. Both good and poor outcome groups initially had striking forensic histories and significant differences developed over the follow-up period with the poor outcome group continuing to have marked legal problems. In addition the poor outcome group continued to make heavy demands on the medical services over the period. One person died from an alcohol related cause. Greater attention to the specific needs of this group is required and specialized treatment units for young problem drinkers is suggested.

Adolescent↗
PubMed1993

Baboon-to-human liver transplantation.

Our ability to control both the cellular and humoral components of xenograft rejection in laboratory experiments, together with an organ shortage that has placed limits on clinical transplantation services, prompted us to undertake a liver transplantation from a baboon to a 35-year-old man with B virus-associated chronic active hepatitis and human immunodeficiency virus infection. Liver replacement was performed according to conventional surgical techniques. Immunosuppression was with the FK 506-prednisone-prostaglandin regimen used routinely for hepatic allotransplantation, to which a daily non-myelotoxic dose of cyclophosphamide was added. During 70 days of survival, there was little evidence of hepatic rejection by biochemical monitoring or histopathological examination. Products of hepatic synthesis, including clotting factors, became those of the baboon liver with no obvious adverse effects. Death followed a cerebral and subarachnoid haemorrhage that was caused by an angioinvasive aspergillus infection. However, the underlying cause of death was widespread biliary sludge that formed in the biliary tree despite a seemingly satisfactory choledochojejunostomy. During life and in necropsy samples, there was evidence of the chimerism that we believe is integral to the acceptance of both xenografts and allografts. Our experience has shown the feasibility of controlling the rejection of the baboon liver xenograft in a human recipient. The biliary stasis that was the beginning of lethal infectious complications may be correctable by modifications of surgical technique. In further trials, the error of over-immunosuppression should be avoidable.

AIDS-Related Opportunistic Infections↗
PubMed1993

An intelligent and cost-effective computer dosing system for individualizing FK506 therapy in transplantation and autoimmune disorders.

The accuracy and precision of an intelligent dosing system (IDS) for FK506 in predicting doses to achieve target drug levels has been prospectively evaluated in transplant and autoimmune patients. For dose individualization, the knowledge base is updated with patient-specific feedback including the current dose, drug level, and the new target level. The study population of 147 patients consisted of 97 transplant patients (liver and kidney) and 50 patients with autoimmune disorders. Patients in the transplant study group were entered sequentially and followed as a cohort. Patients in the autoimmune study group were randomly assigned to one of three predefined FK506 concentration windows (low, 0.1-.3; medium, 0.4-.7; and high, 0.8-1.3 ng/mL) as part of a concentration controlled clinical trial. Predictions of steady-state plasma drug levels were made throughout the clinical course of autoimmune patients and during the first 6 weeks post-transplant in liver and kidney recipients. FK506 concentration in plasma was measured by a monoclonal antibody based ELISA assay. Accuracy was computed as the mean prediction error (mpe). Precision was computed as the root mean squared prediction error (rmspe). The accuracy of the IDS in each study group was as follows: 0.016 ng/mL (liver), -0.034 ng/mL (kidney), and -0.022 ng/mL (autoimmune). Because the 95% confidence interval included zero in each case, the IDS showed no bias. The precision of the IDS in each study group was as follows: 0.133 ng mL (liver), 0.1903 ng/mL (kidney), and 0.1188 ng/mL (autoimmune). These results indicate that the FK506 IDS is both accurate and very precise (reproducible) in transplant and autoimmune patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The relationship of systemic hemodynamics and oxygen consumption to early allograft failure after liver transplantation.

The early postoperative hemodynamic data of 88 patients who underwent primary liver transplantation between July 1989 and October 1990 at the University Health Center of Pittsburgh were analyzed to establish the relationship of systemic hemodynamics and oxygen consumption to perioperative allograft function. The 15 patients whose allografts failed within the 1st month following transplantation were designated as group 1, while 73 patients who retained adequate graft function constituted group 2. Although the cardiac index and oxygen delivery did not differ significantly between the groups, group 1 consistently demonstrated a lower mean arterial pressure, oxygen consumption, arteriovenous oxygen content difference, and arterial ketone body ratio. The etiology of reduced oxygen consumption in group 1 patients is speculative, but the data support the notion that oxygen consumption is a useful, predictive indicator for liver allograft function after transplantation.

Adolescent↗
PubMed1993

Computer-guided concentration-controlled trials in autoimmune disorders.

A randomized concentration-controlled clinical trial (RCCCT) is an alternate experimental design to the standard dose-controlled study. In a RCCCT, patients are randomly assigned to predefined plasma or blood drug concentration ranges (low, medium, and high). With the caveat that concentration ranges are sufficiently separated, this design should enhance the ability to discover important concentration response relationships. FK-506, a potent and promising immunosuppressive agent for prevention and treatment of graft rejection, has shown significant clinical activity in some immune-mediated disorders. To implement the RCCCT design, a novel FK-506 intelligent dosing system (IDS) was used to guide all doses to prospectively achieve the target concentration range specific in the study protocol. Patients enrolled in these trials suffered from a variety of autoimmune disorders, including multiple sclerosis, primary biliary cirrhosis, psoriasis, autoimmune chronic active hepatitis, and nephrotic syndrome. We observed excellent predictive performance of the IDS for all patients. The accuracy (mean prediction error) of the IDS was -0.022 ng/ml and the precision (standard deviation of the prediction error) was 0.119 ng/ml. Thus, the IDS is both accurate and reproducible for autoimmune patients. We conclude that the RCCCT design, guided by an accurate and precise IDS, is an informative and cost-effective approach for evaluation of efficacy and safety of effective but highly toxic agents.

Autoimmune Diseases↗
PubMed1993

Assessing what high risk young children know about drugs: verbal versus pictorial methods.

Very young children are generally not targeted for drug education efforts for two basic reasons. First, it is generally assumed that young children are not cognitively ready to learn about specific drugs through systematic drug prevention efforts. And second, it is difficult to measure pre- and posttest changes on the part of young children if drug education intervention is instituted. This study involved measuring what children three to eight years old learned from systematic drug education over the course of eight months. Two assessment methods were compared: pictorial and verbal interviews. The posttest results revealed that the children who received the intervention knew significantly more about several drugs than a matched comparison group. Both methods were useful in providing a comprehensive view of what the children knew about alcohol and other drugs.

Audiovisual Aids↗