Sensitivity and specificity of third-generation hepatitis C virus antibody detection assays: an analysis of the literature.

This study assessed the sensitivity and specificity of third-generation serological hepatitis C diagnostic tests from an analysis of the literature. The literature analysis was run using criteria from McMaster University for the assessment of diagnostic tests. The selected studies were grouped according to the type of population at high and low risk for hepatitis C virus (HCV) infection and to the type of reference test. The homogeneity of the sensitivity and the specificity was tested in each group using a Fisher's exact test. Of 132 studies, 10 were selected. When the estimates were homogeneous, summary point estimates and confidence intervals were computed; when the estimates were heterogeneous, subgroup analysis was performed. The sensitivity of third-generation enzyme-linked immunosorbent assay (ELISA3) was estimated at 98.9% (95% CI: 94-100%) in patients with chronic liver disease and at 97.2% (95% CI: 92-99%) in panels of sera. ELISA3 specificity was found at 100% in patients with chronic liver disease. The sensitivity of the third generation recombinant immunoblot assay (RIBA3) was assessed at 78.8% (95% CI: 65-89%) in haemodialysed patients. This analysis provides evidence for the good sensitivity and specificity of ELISA3 assays particularly in high risk patient groups and confirms their use for screening in these populations. Further studies are needed to assess properly RIBA3 in general population and in risk patients.

Epidemiology of hepatitis C virus infection in seven European Union countries: a critical analysis of the literature. HENCORE Group. (Hepatitis C European Network for Co-operative Research.

Hepatitis C is now recognized as the most common infection causing chronic liver disease in the European population. Our aim was to assess the prevalence of the antibody to hepatitis C virus (HCV), and the incidence of HCV seroconversion in the general population and the main risk groups, namely intravenous drug users, haemodialysis and transfused patients, in seven countries of the European Union, by carrying out a critical analysis of the literature. Data sources used were the Medline database and a manual search using the key words: hepatitis C, prevalence, incidence, transmission, risk factors and epidemiology. Articles published between January 1990 and March 1997 were reviewed. Articles were reviewed according to a critical analysis method regarding title, type of article, study design, period and population, tests, results and their consistency with data. The tests performed were mainly second- or third-generation serological tests. The average prevalence rate in blood donors was 1%, with a north-south gradient ranging from 0.04% to 2%. Prevalence varied from 20% to 30% in haemodialysis patients. The incidence in transfused patients was less than 1% after 1991. The prevalence in intravenous drug users was about 80%. Multicentre studies conducted in larger samples are needed to obtain more accurate and reliable results, in particular. However, the epidemiological studies available allowed us to assess the magnitude of HCV infection in Europe.

[Economic impact of the consensus conference guidelines on postoperative artificial nutrition in the Rhone-Alps region]. / Impact économique des recommandations de la conférence de consensus sur la nutrition artificielle postopératoire en région Rhône-Alpes.

OBJECTIVES: To assess the economic impact of the French guidelines produced by the 1994 consensus conference on postoperative artificial nutrition (AN) in elective surgery. STUDY DESIGN: Multicentre before-after study, conducted on a cost-containment model from the hospital perspective. PATIENTS AND METHODS: Ten hospitals were randomly selected in the Rhône-Alpes area, after a stratification of hospital category. Twenty consecutive patients, who underwent upper and lower abdominal surgery in each hospital, were included over each study period. Data were collected on site by investigators from patients' records before (1994) and after (1995) guidelines had been circulated. The calculated costs were direct and partial medical and non medical staff costs of a one-day parenteral nutrition. They included nutrients, disposable devices, staff time and laboratory tests. RESULTS: Between 1994 and 1995, the study showed a 7.4% decrease in the postoperative prescription rate of AN, a 4.7% increase in the duration of AN and a 3.6% (FF 74.07 constant francs per patient) increase in the total cost of AN in surgical patients. Guidelines had mainly a positive impact in patients suffering from denutrition, as the duration of postoperative AN increased by 23.7% in this group, leading to a 65.1% (FF 175.53) increase in cost in 1995. CONCLUSIONS: The cost variable is a valuable indicator of the impact of practice guidelines, as it includes the rate and duration of prescriptions. The consensus conference had a significant impact in patients suffering from denutrition. Conversely, only minor changes in practices concerning patients non suffering from denutrition have been observed, leading to a slight cost increase in AN.

Perioperative artificial nutrition in elective surgery: an impact study of French guidelines.

OBJECTIVE: In France, the consensus conference, held on 16 December 1994, produced guidelines on perioperative artificial nutrition (AN) use in patients undergoing elective surgery. The aim of this study was to assess the impact of these guidelines on practice patterns. METHODS: The study was a practice pattern study with a 'before-after' design and a control group in England. A retrospective cross-sectional sample of adult patients undergoing elective resection of the digestive tract was collected in France and England before and after the consensus conference. RESULTS: Malnourished patients received postoperative AN in 94% of 'before' cases and 82% 'after' but inadequate preoperative AN (40% 'before' and 26% 'after'). Postoperative AN appeared to be over-prescribed in non-malnourished patients without prolonged postoperative fasting (70% 'before' and 65% 'after'). In the English sample there was no significant variation in AN use between 'before' and 'after' periods. CONCLUSION: This study shows that clinical guidelines disseminated by consensus conference had a low impact on practice patterns in France and thus confirms the need to enforce the dissemination of the guidelines.

[Perioperative artificial nutrition in elective surgery. A descriptive study of practice patterns in France]. / Nutrition artificielle périopératoire en chirurgie réglée. Etude descriptive des pratiques en France.

OBJECTIVE: To analyse the practice patterns of perioperative artificial nutrition in France before the Consensus Conference held on 16 december 1994 and to compare them with the recommendations produced by this Conference. STUDY DESIGN: Retrospective cross-sectional practice patterns study. PATIENTS: Sample of patients collected from general or digestive tract surgeons, including for each one the last two patients having had before 10 December 1994 either elective upper (oesophagectomy, duodenopancreatectomy) or elective lower (colectomy) abdominal surgery. The response rate to the 2, 150 circulated questionnaires was 14% (309), producing a sample of 601 patients (49% with upper abdominal surgery, 51% with lower abdominal surgery). RESULTS: The geographical distribution of surgeons who replied and their type of activity (private or public) was similar to the national pattern, however with some underrepresentation of the larger Paris area. The duration of pre- or postoperative artificial nutrition was bellow seven days in 36% of the cases, and above this delay in 64% of the cases. Artificial feeding rates for upper abdominal surgery, were 9 and 75%, respectively (duration of artificial feeding of 7 days and more being only considered). For lower abdominal surgery, these rates were 5 and 41%, respectively. Enteral nutrition was given in 13% of preoperative cases and 19% of postoperative ones; the others received parenteral nutrition. When compared to the recommendations by the Consensus Conference, these results show an insufficient use of preoperative artificial nutrition in patients with malnutrition (only 22% of them received it) and an excessive use in postoperative patients, particularly after lower abdominal surgery. Furthermore, the caloric intake was in accordance with the recommendations in only 20% of the cases. It was too high in 38% of the cases and insufficient in 47% of them. Similarly, the postoperative nitrogen intake complied with the recommended figures in only 5% of the cases. CONCLUSION: This study highlights large discrepancies between the recommendations by the Consensus Conference and current practice patterns. It questions the efficiency of this therapy as it is implemented today and generates high and unwarranted expenses.

[Hemodynamic effects of fentanyl during anesthesia with 2 concentrations of enflurane]. / Effets hémodynamiques du fentanyl lors d'anesthésies à deux concentrations d'enflurane.

The cardiovascular effects of intravenous fentanyl were determined in eleven patients undergoing intra-abdominal surgical procedures under enflurane anaesthesia. The patients were curarized with pancuronium and ventilated with nitrous oxide (50%) in oxygen. The systemic arterial pressure (Pa) was measured by means of a left radial arterial catheter. The pulmonary artery pressure (Ppa), the pulmonary wedge pressure (Ppw), the cardiac output, the pH and blood gases of mixed venous blood were measured by means of a thermodilution Swan-Ganz catheter. Before the surgical procedure, the measurements were carried out 10 and 20 min after the administration of 0.8% enflurane, and 5 and 15 min after 5 micrograms X kg-1 intravenous fentanyl. During surgery, the measurements were repeated under 0.8% enflurane, and then after 10 and 20 min of receiving 1.6% enflurane, and 5 and 15 min after a second intravenous injection of fentanyl (5 micrograms X kg-1).(ABSTRACT TRUNCATED AT 250 WORDS)