LIVER BIOPSY VERSUS ULTRASOUND IN METHOTREXATE-TREATED PSORIASIS: A DECISION ANALYSIS

Before starting methotrexate therapy for cases of recalcitrant psoriasis, a liver biopsy has been usual in order to exclude cirrhosis and moderate or severe fibrosis, which are contraindications for methotrexate treatment. As mortality and morbidity of liver biopsy are not negligible, and as this invasive procedure is unpleasant for the patient and urges clinical admission, we evaluated the possibility of ruling out severe liver pathology by means of ultrasonography, which we compared to liver biopsy. We made this comparison by means of a decision tree. The advantages of this analysis are the clear definition of the decision problem and its alternatives, and the possibility of calculating the risk of each alternative, thus being able to choose the best diagnostic method. In this study, the results of various research groups are discussed, in which liver biopsy and liver ultrasound were compared. In our decision tree we used some of these results and other assumptions, based on comparable studies. We varied the biopsy mortality and the sensitivity of ultrasound to show the change in the risk of each alternative. Our analysis shows that the differences of expected values between the liver biopsy branch and the ultrasonography branch are relatively small. Therefore, we advise each center, which has at its disposal a specialist in liver ultrasonography, to re-evaluate its guidelines with regard to the detection of severe liver pathology before starting methotrexate for the treatment of psoriasis.     

A survey of forensic psychologists’ work with sex offenders in England and Wales

This paper describes the results of a survey of the extent and variety of work with sex offenders by psychologists working in different forensic settings in England and Wales. A postal questionnaire was sent out to all 199 psychologists in the special hospitals, regional forensic psychiatry services, prisons and youth treatment service requesting details about their work with sex offenders during the year June 1991 to July 1992. The results are described under the headings of assessment and treatment; supervision, consultation, teaching and training; research and evaluation. The discussion highlights some of the patterns and trends of the work of forensic psychologists with sex offenders, together with the range of psychological interventions. There are also patterns within services. Results of the survey highlight the links psychologists have with other disciplines in working with sex offenders and raise questions about the most appropriate model of psychology practice, given the limited resources.     

Evaluation of an Australian intervention to encourage breast feeding in primiparous women

Breast feeding has nutritional, immunologic and antiallergicadvantages for the infant. Although it has been widely recommendedthat infants be exclusively breast fed until 4–6 monthsof age, only about half of all Australian babies currently receiveextended breast feeding. The present study evaluated an intensiveprogramme designed to increase the proportion ofprimi-parousmothers who breast fed for 4 months or longer. Women who registeredwith the hospital at least 20 weeks before delivery and whointended to breastfeed were eligible for the study. Two hundredand thirty-five women were allocated to receive either usualcare or an intensive breast feeding programme when they registeredwith the hospital. The intensive programme consisted of writtenmaterials, and group and individual sessions with a lactationcounsellor. It also included a visit from a breastfeeding consultantwhile in hospital after the birth and contact on return home.Women were followed up 6 weeks and 4 months after delivery.There were no significant differences in breastfeeding ratesbetween the control and intervention groups at either follow-uppoint. Breast feeding until 4 months was more likely among womenwhose baby did not receive a bottle feed while still in hospitaland who did not smoke, use the combined oral contraceptive pillor introduce solid food before 4 months. Those mothers who enjoyedand felt satisfied with breastfeeding were more likely to continueto 4 months. It seems likely that programmes designed to increasebreastfeeding will need to address underlying factors such ashospital policy rather than simply providing more health education.     

A Critical Period of Ventricular Fibrillation More Susceptible to Defibrillation: Real-Time Waveform Analysis Using a Single ECG Lead

Previous studies have suggested that variations in the underlying ventricular fibrillation (VF) waveform may be one of the factors responsible for the probabilistic nature of defibrillation. The heart appeared to be more susceptible to defibrillation at higher absolute VF voltages (AVFV). This study investigated in an open-chest canine model (n = 8), a newly developed system that analyzed the VF waveform in real-time, instantaneously determined the time to shock, and immediately delivered a fixed low energy DC shock. A two parameter tracking technique using a running long-term and short-term AVFV average was devised to automatically identify a high voltage peak area of the VF waveform, which has been hypothesized to represent a critical period susceptible to defibrillation. Using a DC shock estimated at the 50% success level, the performance using this technique in 58 defibrillation trials was compared to the performance of the conventional method of shocking at a fixed time (random shock method) in 62 trials. Patch size, electrode location, and discharge voltage were kept constant while VF duration, transmyocardial resistance (TMR), energy delivered, and AVFV at the point of shock were measured. Shock energy and current, TMR, and VF duration were similar with both shock methods. A significantly higher AVFV was observed for trials performed with the peak shock method (0.66 ± 0.02 mV) as compared to trials performed with the random shock method (0.25 ± 0.09 mV) (P < 0.003). Using lead II as the only sensing lead, the success rate was increased in 6 of 8 dogs (75%) with the new method. One animal showed identical performance, and one animal a worse performance. The overall increase in success rate was 24% using a single ECG lead (range 0%-100%; P < 0.04). Our data document that using this algorithm a period of high VF voltage can be detected in realtime. The improved success in the majority of animals supports the hypothesis that a critical period susceptible to defibrillation exists during VF. However, the high AVFV detected using a single ECG lead did not translate to an improved success rate in all animals. This suggests that other factors in addition to the VF voltage measured on a single lead of the ECG are important in characterizing this critical period.     

Rate-Related and Autonomic Effects on Atrioventricular Conduction Assessed Through Beat-to-Beat PR Interval and Cycle Length Variability

Atrioventricular Conduction Variability. Introduction: Atrioventricular AV) conduction time varies on a beat-by-beat basis in response to the influences of cardiac efferent autonomic activity and rate-dependent electrical recovery processes. The goals of this study were to distinguish these effects on AV conduction time and to compare the variability in sinoatrial and AV nodal function. Methods and Results: The PR interval on the surface ECG served as an index of AV conduction time in this study of 14 adult human subjects undergoing a random interval breathing protocol. P and R waves were located by a template-matching algorithm. Spectral analysis allowed frequency-domain comparisons between PR and RR interval variability. Spectra of PR and RR intervals had similar power distributions, although the power of the RR interval spectra was much greater. Autonomic blockade with atropine plus propranolol reduced the power of both spectra. Standing significantly decreased the spectral power from 0.15 to 0.5 Hz for PR and RR spectra, and introduced a peak near 0.1 Hz in the mean PR and RR spectra, although the latter finding was significant only for the RR interval spectra. Propranolol had no significant effects on the PR and RR interval spectra. Linear regression analysis allowed quantification of the autonomic and recovery effects on AV conduction and showed which effect predominated. Simple linear regression confirmed in adults a previous finding in children that conduction time may be either positively or negatively correlated with cycle length. By multiple regression and transfer function analysis, the inverse relation seen in some subjects was attributed to the effect of recovery from the preceding cycle. With the preceding recovery period accounted for, the conduction time and cycle length of the current beat were positively correlated, presumably due to the parallel autonomic effects on the sinoatrial and AV nodes. The magnitude of the recovery effect predicted by the regression analysis was similar to published values. Conclusion: A noninvasive evaluation of the surface ECG can be used to compare variability in AV conduction time and cycle length and characterize the effects of autonomic efferent activity and rate-related recovery on AV nodal function.     

USE OF I.M. RANITIDINE FOR THE PROPHYLAXIS OF ASPIRATION PNEUMONITIS IN OBSTETRICS

Twenty patients who underwent elective Caesarean section receivedranitidine 150 mg by mouth 8–14 h, and 50 mg i.m. 90 min,before surgery. Intraoperative gastric aspiration resulted incontents with a pH > 2.5 and volume < 25 ml in all patients(mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patientsin labour, who received ranitidine 50 mg i.m. 6-hourly, underwentemergency surgery. Half of this group received, in addition,a single preinduction dose of either 15 or 30 ml of sodium citrate0.3 mol litre^-1. A further 30 patients who remained unmedicatedduring labour and required emergency surgery received a preinductiondose of 15 or 30 ml of sodium citrate 0.3 mol litre^-1 alone.Ranitidine medication resulted in a mean aspirated gastric volumeof 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients hada pH < 2.5. The addition of sodium citrate 0.3 mol litre^-1resulted in gastric pH > 2.5 in all patients and a mean gastricvolume of 43.2 (38.3) ml. The group who received only sodiumcitrate 0.3 mol litre^-1 had a mean pH of 5.3 (1.1) and a meanvolume 122.7 (98.2) ml.     

A Hemodynamically Responsive Antitachycardia System: Theoretical Bases for Design

Current antitachycardia systems such as the automatic implantable cardioverter/defibrillator (AICD), detect tachyarrhythmias primarily by sensing rate and thereby perform inadequately in differentiating hemodynamically stable from unstable arrhythmias. As a result, these devices may discharge during stable tachycardias (such as sinus tachycardia), causing discomfort to the patient and depleting the device's limited energy supply. If a parameter which could reflect the particular hemodynamic state of a tachycardia were incorporated into the sensing algorithm of these systems, function may be more hemodynamically precise and discharge specificity may be improved.     

Intrapartum Care of a Woman With Aortic Aneurysms

Advances in technology and complex care have enabled women with various health problems to become and remain pregnant. Consequently, health-care practitioners are seeing an increasing number of pregnant women who have aortic aneurysms. This case study describes the culturally sensitive intrapartum care of a Middle Eastern woman with ascending and descending aortic aneurysms.