Biomedical subjects

Robert Gagnon

Publications and source records attributed to Robert Gagnon.

11 recordsLinked to original sources

PubMed2003

Placental insufficiency and its consequences.

Placental insufficiency is a process leading to progressive deterioration in placental function and a decrease in transplacental transfer of oxygen and nutrients to the fetus. The resulting fetal hypoxemia is the major stimulus involved in the reduction in fetal growth as an attempt to reduce metabolic demands by the growing fetus. Fetal growth restriction (FGR) is the second cause of perinatal death after prematurity and can complicate up to 6% of all pregnancies. It is becoming apparent that its occurrence has major impacts on the fetus and placenta with consequences on the cardiovascular, metabolic and neurological development up to adulthood. We are just starting to unveil some of the basic mechanisms involved in this complex adaptation that may lead to reprogramming of fetal organs development mostly the heart, pancreas, lungs and brain. It is becoming clear that future research is needed to develop strategies to improve antenatal detection of FGR, in addition to reduce the risk of abnormal neurodevelopment during childhood, and onset of common diseases in adulthood following pregnancies complicated with placental insufficiency.

Animals↗

PubMed2003

Intrauterine herpes simplex infection.

Neonatal herpes simplex virus (HSV) infection is usually acquired at birth. We present an infant with intrauterine HSV infection acquired after rupture of membranes. The infant was born prematurely to a woman with a first episode of genital herpetic infection in early pregnancy and rupture of membranes 11 days prior to delivery. The infant, at delivery had extensive brain damage, hemorrhage, and cystic encephalomalacia due to herpes infection. On 2nd day of life, Magnetic Resonance Imaging, suggested that the hemorrhage had occurred 7 to 14 days before the scan and the placental pathology was supportive of an ascending infection. The case of an ascending herpetic intrauterine infection after rupture of the membranes raises the question of prevention and suppressive antiviral therapy.

Abnormalities, Multiple↗

PubMed2003

The risks of adverse neonatal outcome among preterm small for gestational age infants according to neonatal versus fetal growth standards.

OBJECTIVE: To evaluate neonatal and fetal growth standards in determining the impact of small for gestational age (SGA) on neonatal mortality and morbidity. DESIGN: A hospital-based cohort study of infants born in a regional tertiary care center and admitted to the neonatal intensive care unit. SETTING AND PARTICIPANTS: A total of 1267 singleton neonates of <34 weeks gestational age, without any congenital anomalies, born between January 1, 1993 and December 31, 2001. OUTCOME MEASURES: Each outcome variable including mortality, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage (IVH), periventricular leukomalacia, and necrotizing enterocolitis was related to growth status as defined by fetal and neonatal growth standards after adjustment for potential confounders. RESULTS: The number of SGA infants was 11.6% (n = 147) of the study population according to neonatal growth standards, but it was increased to 23.3% (n = 295) when fetal growth standards were used. According to fetal growth standards, when SGA was compared with appropriate for gestational age infants, it was associated with an increased risk of respiratory distress syndrome (odds ratio [OR] 1.40; 95% confidence interval [CI] 1.00-1.95), bronchopulmonary dysplasia (OR 2.18; 95% CI 1.33-3.59), IVH (OR 1.67; 95% CI 1.13-2.45), and retinopathy of prematurity (OR 3.88; 95% CI 2.33-6.48). However, only neonatal mortality (OR 3.64; 95% CI 1.64-8.09), retinopathy of prematurity (OR 5.38; 95% CI 2.87-10.90), and necrotizing enterocolitis (OR 2.47; 95% CI 1.21-5.07) were positively associated with SGA when using neonatal growth standards. CONCLUSIONS: Compared with the neonatal growth standards, the fetal growth standards are better in identifying increased risk of respiratory morbidity and IVH among preterm SGA infants.

Cohort Studies↗

PubMed2003

The use of fetal Doppler in obstetrics.

OBJECTIVE: To develop national guidelines on the use of fetal Doppler in obstetrics. OPTIONS: Whether umbilical cord artery, umbilical cord venous, ductus venosus, and middle cerebral artery Doppler are useful in assessing fetal health. OUTCOME: Prediction of adverse perinatal outcome or prediction of fetal anemia. EVIDENCE: MEDLINE search and review of bibliographies in identified articles. VALUES: The evidence was reviewed by the Diagnostic Imaging Committee and the principal authors. A quality of evidence assessment was undertaken as outlined in the report of the Canadian Task Force on the Periodic Health Examination. BENEFITS, HARMS, AND COSTS: Intrauterine growth restriction complicates 5% to 10% of all pregnancies and up to 30% of multiple pregnancies. In 60% of these pregnancies, the primary cause is placental insufficiency. Improvement in the identification of the fetus at risk of intrauterine demise may lead to more successful management strategies. Management of fetal red blood cell isoimmunization requires a prediction of fetal anemia. If invasive procedures to predict fetal anemia can be replaced with noninvasive tests, fetal morbidity and mortality can be reduced. RECOMMENDATIONS: 1. Umbilical artery Doppler should be available for assessment of the fetal-placental circulation in pregnant women with suspected severe placental insufficiency. (I-A) 2. Depending on other clinical factors, reduced, absent, or reversed umbilical artery end-diastolic flow is an indication for enhanced fetal surveillance or delivery. If delivery is delayed to enhance fetal lung maturity with maternal administration of glucocorticoid, intensive fetal surveillance until delivery is suggested for those fetuses with reversed end-diastolic flow. (II-1B) 3. Umbilical artery Doppler should not be used as a screening tool in healthy pregnancies, as it has not been shown to be of value in this group. (I-A) 4. Umbilical venous double pulsations, in the presence of abnormal umbilical artery Doppler waveforms, necessitate a detailed assessment of fetal health status. (II-3B) 5. Measurement of the fetal middle cerebral artery Doppler peak systolic flow velocity is a predictor of moderate or severe fetal anemia and can be used to avoid unnecessary invasive procedures in pregnancies complicated with red blood cell isoimmunization. (II-1A) 6. Since inaccurate information concerning fetal Doppler studies could lead to inappropriate clinical decisions, it is imperative that measurements be undertaken and interpreted by expert operators who are knowledgeable about the significance of Doppler changes and who practise appropriate techniques. Duplex mode with pulsed Doppler and colour Doppler flow mapping is the minimum required ultrasound equipment. (II-1A)

Blood Flow Velocity↗

PubMed2002

Assessment of clinical reasoning competence in urology with the script concordance test: an exploratory study across two sites from different countries.

OBJECTIVES: The script concordance (SC) test is designed to measure the organisation of knowledge that allows interpretation of data in clinical reasoning. This study explores the use of this new written examination tool in urology. MATERIALS AND METHODS: An 80 items SC test was administered to participants from a French and a Canadian university. Three levels of experience were tested: urologists (n = 22), residents in urology (n = 25) and students (n = 23). Scores between groups were compared by analysis of variance. Reliability analysis was studied with Cronbach alpha coefficient. RESULTS: Mean global scores were 51.45 +/- 5.29 for students, 58.19 +/- 3.81 for residents and 62.27 +/- 5.46 for urologists. The difference between the three groups was statistically significant (P < 0.00001). Interaction between levels of expertise and sites was apparently not significant (P = 0.326). Cronbach alpha was 0.79 for the test. CONCLUSIONS: This study shows that the SC test is able to discriminate among participants according to their levels of clinical experience in urology. The results are similar in two different learning environments. The SC test appears as a simple and direct approach to testing organisation and use of knowledge in urology.

Clinical Competence↗

PubMed2002

Amniotic fluid and fetal urinary responses to severe placental insufficiency in sheep.

OBJECTIVE: Our purpose was to test the hypothesis that severe placental insufficiency leads to reductions in fetal urine production and amniotic fluid volume in late-gestation fetal sheep. STUDY DESIGN: At 0.85 of gestation, chronically catheterized fetal sheep with ligated urachus were either embolized for 5 days by repeated injection of boluses of 15-microm microspheres into the common fetal umbilical artery until fetal arterial oxygen content was reduced by 50% (n = 6) or were infused with saline solution (n = 6). Amniotic fluid volume was measured daily before embolization by means of an indicator dilution technique and by drainage at autopsy. Fetal urine production, heart rate, and mean arterial blood pressure were measured continuously for 1 hour before embolization and 1 hour after embolization each day. Fetal arterial blood gases, oxygen content, electrolytes, and osmolality were also monitored. RESULTS: Five days of placental insufficiency, which reduced fetal arterial oxygen content by 50% and arrested fetal growth, resulted in a reduced amniotic fluid volume without a reduction in fetal urine production. Compared with that of controls, amniotic fluid volume was reduced over the 5-day period by 547 +/- 144 mL (-62%, P <.01). Amniotic fluid composition was also altered, with a significant increase in lactate and sodium concentrations and osmolality on days 4 to 5. On days 2 to 5, there was a progressive increase in amniotic fluid osmolality above that of controls, which paralleled the changes in amniotic fluid sodium concentration (P <.05). Fetuses became hypertensive on days 2 to 4 of embolization, although this response was attenuated by day 5. CONCLUSIONS: Chronic severe placental insufficiency caused a reduction in amniotic fluid volume not attributable to reduced fetal urine production. Changes in amniotic fluid composition induced by placental insufficiency suggest an excess intramembranous absorption of amniotic fluid water, in relation to solutes, into the fetal and maternal compartments, which may lead to the development of oligohydramnios.

Amniotic Fluid↗

PubMed2002

Stability of clinical reasoning assessment results with the Script Concordance test across two different linguistic, cultural and learning environments.

The Script Concordance (SC) test is designed to measure the organization of knowledge that allows interpretation of data in clinical reasoning. An originality of the test is that answer keys use an aggregate scoring method based on answers given by a panel of experts. Previous studies have shown that the SC test has good construct validity. This study, done in urology, explores (1) the stability of the construct validity of the test across two different linguistic and learning environments and (2) the effect of the use of experts who belong to different environments. An 80-item SC test was administered to participants from a French and a Canadian university. Two levels of experience were tested: 25 residents in urology (11 from the French university and 14 from the Canadian university) and 23 students (15 from the French faculty, eight from the Canadian faculty). Reliability analysis was studied with Cronbach's alpha coefficient. Scores between groups were compared by analysis of variance. Reliability coefficient of the 80 items test was 0.794 for the French participants and 0.795 for the Canadian participants. Scores increased with clinical experience in urology in the two sites. Candidates obtained higher scores when correction was done using the answer key provided by the experts from the same country. These data support the stability of the construct validity of the tool across different learning environments.

Adult↗

PubMed2002

Methods for data mining from large multinational surveillance studies.

Traditionally, large surveillance studies have been analyzed by the use of the MICs at which 90% of isolates tested are inhibited (MIC(90)s), MIC(50)s, frequency distributions, and percent susceptibility. In the past, these approaches have proved satisfactory for the monitoring of resistance. From these traditional uses, one can readily detect an increase in MICs for organism and drug combinations. Now that large surveillance studies have been conducted for a number of years and databases have grown to include a large number of datum points, new approaches to the extraction of useful information from these studies are needed. The present study proposes approaches, including the use of antibiotypes, principal components analysis, phylogenetics, and population genetic analysis, to the evaluation of data from large multinational surveillance studies. Application of these types of analyses can be used to describe genetic diversity, analyze changes in susceptibility patterns over time, and possibly, shed light on the origins and evolution of antimicrobial resistance. As global surveillance studies become more common and new questions concerning the evolution of resistance are raised, innovative approaches to analysis of the data will increase in importance.

Algorithms↗

PubMed2002

Comparison of an aggregate scoring method with a consensus scoring method in a measure of clinical reasoning capacity.

BACKGROUND: Diversity of clinical reasoning paths of thought among experts is well known. Nevertheless, in written clinical reasoning assessment, the common practice is to ask experts to reach a consensus on each item and to assess students on a unique "good answer." PURPOSES: To explore the effects of taking the variability of experts answers into account in a method of clinical reasoning assessment based on authentic tasks: the Script Concordance Test. METHODS: Two different methods were used to build answer keys. The first incorporated variability among a group of experts (criterion experts) through an aggregate scoring method. The second was made with the consensus obtained from the group of criterion experts for each answer. Scores obtained with the two methods by students and another group of experts (tested experts) were compared. The domain of assessment was gynecology-obstetric clinical knowledge. The sample consisted of 150 clerkship students and seven other experts (tested experts). RESULTS: In a context of authentic tasks, experts' answers on items varied substantially. Amazingly, 59% of answers given individually by criterion group experts differed from the answer they provided when they were asked in a group to provide the "good answer" required from students. The aggregate scoring method showed several advantages and was more sensitive to detecting expertise. CONCLUSIONS: The findings suggest that, in assessment of complex performance in ill-defined situations, the usual practice of asking experts to reach a consensus on each item reduces and hinders the detection of expertise. If these results are confirmed by other researches, this practice should be reconsidered.

Cluster Analysis↗

PubMed2002

Participants' perception of impact of a workshop on their preventive practices.

A 90-minute interactive workshop, offered to small groups on request, was developed to help physicians include evidence-based preventive interventions in their practices. Between 25 September 1996 and 10 December 1997, 593 family physicians throughout the Province of Quebec (Canada) participated in one of the 40 workshops presented in all the regions of Quebec. Almost all participants (98%) completed the self-administered questionnaire. Their opinion of the achievement of three workshop objectives were evaluated using a seven-point Likert scale (-3 to +3)as their perception of the direct impact of the workshop on their practice. The workshop objectives were reached to a high degree: 2.1 (sd 0.90) for prescribing a proper check-up for adults; 1.83(sd 1.02) for explaining to the patient the reasons motivating his/her choice to include or exclude certain tests; 2.09 (sd 0.93)for using concrete and useful tool facilitating the integration of preventive measures in his/her professional practice. Female physicians and those under 40 perceived that the objectives were reached to a greater degree. Participants indicate their intention to modify their practice according to the clinical practice guidelines presented in the workshop.

Adult↗

PubMed2002

Performance assessment. Family physicians in Montreal meet the mark!

OBJECTIVE: To assess the clinical performance of a representative non-volunteer sample of family physicians in metropolitan Montreal, Que. DESIGN: Assessment of clinical performance was based on inspection visits to offices, peer review of medical records, and chart-stimulated recall interviews. The procedure was the one usually followed by the Professional Inspection Committee of the Collège des médecins du Québec. SETTING: Family physicians' practices in metropolitan Montreal. PARTICIPANTS: One hundred randomly selected family physicians. INTERVENTIONS: For each physician, 30 randomly chosen patient charts with data on three to five previous visits were reviewed using explicit criteria and a standard scale using global scores from 1 to 5 (unacceptable to excellent). MAIN OUTCOME MEASURES: Scores were assigned for office practices; record keeping; number of continuing medical education (CME) activities; and quality of clinical performance assessed in terms of investigation plan, diagnostic accuracy, treatment plan, and relevance of care. RESULTS: Overall performance was judged to be good to excellent for 98% of physicians in their private practices; for 90% of physicians concerning CME activities; for 94% of physicians concerning their clinical performance in terms of quality of care; and for 75% of physicians as to record keeping. There was a link between record keeping and quality of care as well as between the number of CME activities and quality of care. CONCLUSION: The overall clinical performance of family physicians in the greater Montreal region is excellent.

Adult↗