Atrial natriuretic peptide and blood volume in patients with chronic glomerulonephritis: effects of albumin and frusemide administration

Blood volume, blood pressure, plasma concentrations of atrial natriuretic peptide (ANP), cyclic 3',5'-guanosine monophosphate (cGMP), angiotensin II, aldosterone, and arginine vasopressin (AVP), and urinary excretion rates of cGMP, sodium, and water were determined before and after infusion of human albumin 20%, 3.5 ml/kg body-weight to 12 patients with chronic glomerulonephritis and 19 healthy control subjects (Study 1); and before and after frusemide injection, 0.75 mg/kg to 15 patients with chronic glomerulonephritis and 19 healthy control subjects (Study 2). In Study 1 blood volume was expanded to the same degree in patients (8.8 and 7.5%, medians, after 90 and 180 min) and controls (8.6 and 6.1%). ANP was enhanced in the patients (5.9 to 11.0 pmol/l, P less than 0.01) and the controls (4.9 to 7.1 pmol/l, P less than 0.01), but the elevated level was protracted in the patients simultaneously with a delayed sodium excretion. Plasma cGMP increased, aldosterone decreased and AVP was unchanged in both groups, whereas angiotensin II decreased in the patients (P less than 0.01), but not in the controls. In Study 2 blood volume was reduced to a smaller extent in the patients than in the controls (8.9% versus 9.9%, P less than 0.05). ANP an cGMP decreased, and angiotensin II, aldosterone and AVP increased in both patients and controls. In conclusion, patients with glomerulonephritis respond to albumin- and frusemide induced changes in blood volume with essentially the same counter-regulatory changes in ANP, angiotensin II, aldosterone and AVP as do healthy subjects. The more protracted increase in ANP and the decrease in angiotensin II after albumin, and the smaller blood volume reduction after frusemide suggest an abnormal regulation of blood volume in glomerulonephritis.     

Negative symptoms in schizophrenia: considerations for clinical trials

There is little agreement about the methodology of clinical trials of antipsychotic drugs in patients with negative symptoms. A literature review revealed wide variation in experimental design, rating scales and study duration. This reflects differing views as to the definition and response to treatment of negative symptoms. Some degree of standardization would improve comparability of studies and aid the development of new compounds. Patients included in such studies should have displayed negative symptoms for at least 6 months. Depressive symptoms, positive schizophrenic symptoms and extrapyramidal signs may all influence or be confused with negative symptoms and may respond to treatment; they should be at a low level at baseline and should be measured during the study period. Studies should last at least 8 weeks. Several scales are available for measuring negative symptoms and are reviewed; a global impression score should be used additionally.     

Country-specific cost-effectiveness of early intervention with budesonide in mild asthma.

Early intervention with budesonide is an effective strategy for mild persistent asthma, which has been shown to provide additional clinical benefits at a low incremental cost using USA cost data. The present authors analysed whether this strategy would be cost-effective using cost data for other countries. Based on the 3-yr prospective, randomised, double-blind inhaled Steroid Treatment As Regular Therapy (START) in early asthma study (comparing budesonide and placebo combined with usual asthma therapy), the cost-effectiveness was estimated separately for eight different countries, from both healthcare payer and societal perspectives, of adding budesonide to usual asthma therapy. Local unit costs were applied to data for the total trial population. Incremental cost-effectiveness ratios (ICER) were estimated as cost per symptom-free day (SFD) gained. Budesonide increased SFDs by an average of 14.1 days annually. From a healthcare payer perspective, budesonide would reduce the total cost of asthma care in Australia. In Sweden, Canada, France, Spain, UK, China and the USA, the ICER ranged from US$2.4-11.3 per SFD. From a societal perspective, budesonide would be cost-saving in Australia, Canada and Sweden. In conclusion, for countries where costs with budesonide are higher, the policy implication has to be determined by that health system's willingness to pay for an additional symptom-free day. However, where budesonide therapy increases symptom-free days and reduces total costs, the policy conclusion clearly favours early intervention.     

Curriculum factors influencing knowledge of communication skills among medical students

Background  

Communication training builds on the assumption that understanding of the concepts related to professional communication facilitates the training. We know little about whether students' knowledge of clinical communication skills is affected by their attendance of communication training courses, or to what degree other elements of the clinical training or curriculum design also play a role. The aim of this study was to determine which elements of the curriculum influence acquisition of knowledge regarding clinical communication skills by medical students.     

Left main coronary artery stenosis no longer a risk factor for early and late death after coronary artery bypass surgery--an experience covering three decades.

OBJECTIVE: To analyse early and late mortality after coronary artery bypass grafting (CABG) in patients with and without left main coronary artery (LMCA) stenosis during the 30-year period 1970-1999. METHODS: A total of 1888 of 10,647 patients (18%) who underwent a first isolated CABG at the Karolinska Hospital in Stockholm, Sweden, during 1970-1999 had significant left main coronary artery stenosis. The Swedish National Cause of Death Register was used to determine mortality up to five years after the operation. RESULTS: The proportion of patients with LMCA stenosis of all CABG patients increased from 7% during the 1970s to 26% in 1999. During 1970-1984 early mortality was 5.8% in patients with LMCA stenosis compared with 1.5% in patients without LMCA stenosis (odds ratio (OR) 3.7 (95% confidence interval (CI) 1.8-7.6)). The corresponding rates during 1995-1999 were 2.0% versus 2.2% (OR 0.8 (95% CI 0.5-1.5)), respectively. The increased risk of early death in patients with LMCA stenosis was neutralised in males during 1985-1994 and in females during 1995-1999. Five-year survival in males was 88% after operations performed during 1994-1999 compared with 82% after CABG performed during 1970-1984. Five-year mortality, exclusive of early deaths, during 1970-1984 was higher in patients with LMCA stenosis (12.8%) than in those without (8.4%) (relative risk 1.7 (95% CI 1.1-2.5)). An increased risk of late mortality in patients with LMCA stenosis was neutralised in males during 1985-1994 and in females during 1995-1999. CONCLUSIONS: During 1970-1999 there was a decrease of early and five-year mortality in patients with LMCA stenosis after CABG despite increase of patient age and risk factors. There were gender differences so that the risk of death in patients with compared with in those without LMCA stenosis was neutralised in males during 1985-1994 and in females during 1994-1999. The continuous decline of mortality during three decades most likely reflects improvement of the peri- and postoperative management of patients undergoing CABG during this period.     

Anal sphincter size measured by endosonography in healthy volunteers. Effect of age, sex, and parity.

The anal sphincter muscles consist of the circular internal and external sphincters together with the sling-shaped associated puborectalis muscle. Ten men, 10 women with no vaginal deliveries, and 10 women with one or more vaginal deliveries were studied with anal endosonography using a 7 MHz multiplanar endoprobe. The thickness of the internal sphincter and the thickness, length, and cross-sectional area of the external sphincter were measured and related to age, sex, and parity. Reproducibility was assessed by similar measurements on different days in 10 volunteers. Anal sphincter size was the same in men and women and was not affected by the number of child births. Internal sphincter muscle thickness increased with age. Anal manometry and electromyography with an anal sponge were performed in all volunteers but the results did not correlate to any of the anal sphincter dimensions. Our conclusion is that although there are some limitations, endosonography can be used to determine the size of the anal sphincter muscles.     

Cerebral blood flow, cerebral metabolic rate of oxygen and relative CO2 reactivity during neurolept anaesthesia in patients subjected to craniotomy for supratentorial cerebral tumours

In 10 patients subjected to craniotomy for supratentorial cerebral tumours in neurolept anaesthesia, cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were measured twice peroperatively by a modification of the Kety & Schmidt technique, using 133Xe. The relative CO2 reactivity was assessed indirectly as the % change of the arteriovenous oxygen difference (AVDO2) per mm change in PaCO2. The patients were premedicated with diazepam 10-15 mg perorally. For induction, thiopentone 4-6 mg/kg, droperidol 0.2 mg/kg and fentanyl 5 micrograms/kg were used, and for maintenance N2O 67% and fentanyl 4 micrograms/kg/h. During the first flow measurement the median and range of CBF was 30 ml/100 g/min (range 17-45), of AVDO2 8.0 vol % (range 4.1-9.5), and of CMRO2 2.28 ml O2/100 g/min (range 1.57-2.84). During the second CBF study, AVDO2 increased to 9.3 vol % (range 3.4-11) (P less than 0.05), and CMRO2 increased to 2.51 ml O2/100 g/min (range 1.88-3.00) P less than 0.05, while CBF was unchanged. The CO2 reactivity was present in all studies, median 1.8%/mmHg (range 0.5-15.1). The correlation coefficients between jugular venous oxygen tension/saturation, respectively, and CBF were high at tensions/saturations exceeding 4.0 kPa and 55%, indicating that hyperperfusion is easily unveiled by venous samples from the jugular vein during this anaesthesia.