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Biomedical subjects

T Rafferty

Publications and source records attributed to T Rafferty.

At least 19 recordsLinked to original sources
PubMed2000

Deliberate self-poisoning presenting at a rural hospital in Northern Ireland 1976-1996: relationship to prescribing.

PURPOSE: This study reports on a project to monitor deliberate self-poisoning in a rural area of Northern Ireland over a 20-year period. Comparison is made with reports from large urban centres. In addition, a local prescribing database allows assessment of any association between psychotropic drug prescription and use for deliberate self-poisoning. MATERIALS AND METHODS: Frequency of self-poisoning, demographic details and drugs used were recorded for all episodes of deliberate self-poisoning occurring at Craigavon Area Hospital for the years 1976, 1986, 1991 and 1996. It was possible to compare prescriptions of psychotropic drugs with their use for deliberate self-poisoning between the years 1991 and 1996 in the region served by the hospital, using the Defined Daily Dose (DDD) system. RESULTS: In this rural area the pattern of deliberate self-poisoning has changed, as in urban centres, with a rise in frequency and the male/female ratio approaching unity. The pattern of drug use has altered, with paracetamol overtaking benzodiazepines as the most commonly used agent. More recently, antidepressants have become the second most frequently used drug class for this purpose. Psychotropic medications used for self-poisoning altered in proportion to their prescription between the years 1991 and 1996. CONCLUSIONS: In the face of a continuing rise in deliberate self-poisoning, which is effecting both urban and rural areas, care should be taken to prescribe the least toxic agent available as this is associated with likely frequency of self-poisoning for most classes of psychotropic drug.

Adult↗
PubMed2000

Field-by-field evaluation of intraoperative transoesophageal echocardiography interpretative skills.

A quality assurance system is essential for the credibility and structured growth of anaesthesiology-based transoesophageal echocardiography (TEE) programmes. We have developed software (Q/A Kappa), involving a 400-line source code, capable of directly reporting kappa correlation coefficient values, using external reviewer interpretations as the 'gold standard', and thereby allowing systematic assessment of the validity of intraoperative echocardiographic interpretation. This paper presents assessment of the validity of 240 intraoperative anaesthesiologists' echocardiographic interpretations, and, in addition, the results of field testing of this prototypical software. Data, derived from consecutive cardiac surgery patients, consisted of standardized two-dimensional transoesophageal echocardiographic, colour flow and Doppler imaging sequences. Intraoperative and off-line 'gold standard' TEE interpretations were compared for 19 fields or variables using the Q/A Kappa program. The kappa correlation coefficients were highly variable and dependent on the examination field, ranging from 0.08 for apical regional wall motion scores to 1.00 for tricuspid regurgitation grade, left atrial measurement, aortic valve anatomy and left ventricular long axis and short axis global function. The correlation coefficients were also operator dependent. These data (480 interpretations) were also manually integrated into the equation required for calculation of values of the variable kappa correlation coefficient. The relationship between Q/A Kappa-derived values and manually calculated values was highly significant (p < 0.001; r = 1.0). The implications and possible explanations of the results for particular examination fields are discussed. This study also demonstrates successful seamless functioning of this software program from data entry, segmentation into tables and valid statistical analysis. These findings suggest that it is practical to provide sophisticated continuous quality improvement TEE data on a routine basis.

Adult↗
PubMed1997

How has fundholding in Northern Ireland affected prescribing patterns? A longitudinal study.

OBJECTIVE: To compare prescribing patterns in general practices before and after the introduction of fundholding in April 1993 to determine whether fundholding changed prescribing patterns among practices that joined the scheme. DESIGN: Analysis of prescribing data from the Drug Utilisation Research Unit's database for all practices in Northern Ireland during April 1989 to March 1996. SETTING: Northern Ireland. SUBJECTS: 23-first wave fundholders, 34 second wave fundholders, 9 third wave fundholders, and 268 non-fundholders. MAIN OUTCOME MEASURES: Prescribing costs per 1000 patients, prescription items per 1000 patients, average cost per item, and rate of generic prescribing. RESULTS: Prescribing costs and frequency increased in all groups throughout the study. Among the fundholders the rate of increase in costs after fundholding was significantly lower than among non-fundholders. The rate of increase in cost per item fell, coinciding with a significant increase in the rate of generic prescribing. However, with regard to first wave fundholders, their yearly increase in costs in their third year as fundholders (1995-6) was similar to that of the non-fundholders. The earlier practices that joined the scheme seemed to differ in some important respects from those that joined later. CONCLUSIONS: After fundholders joined the fundholding scheme their patterns of prescribing changed compared with those of non-fundholders: the rate of increase in costs fell and there was a significant rise in the rate of generic prescribing.

Drug Costs↗
PubMed1997

Temporal trends in drug use in one UK region, revealed by chemical group matching.

(1) The pharmaceutical pricing data for Northern Ireland were amended to include defined daily dosages (DDD) for all single chemical entities. Eight therapeutic groups were studied: antiasthmatics, antidepressants, antimicrobials, benzodiazepines, hormone replacement therapy (HRT), hypoglycaemics, lipid-lowering agents and ulcer-healing drugs. Each group was then subdivided into its main chemical groups. The regional use of each chemical group was defined as the combined DDDs of its individual chemical entities per quarter year, from January 1989 until December 1994. (2) During this period, drug use increased in all eight therapeutic groups and in most of their constituent chemical groups. Increased use of newer drugs did not cause the expected decrease in use of established drugs. Use of all broad-spectrum antimicrobials increased by 314%. Use of sedative benzodiazepines decreased slowly and steadily (16%) throughout the study period but use of all hypnotics increased inexplicably by 21% in 1992 reaching a plateau in 1993 and 1994. SSRI antidepressant use increased sharply (5333%) following their introduction in 1989, accompanied by a 24% increase in use of tricyclic antidepressants. There was a 23,626% increase in the use of proton pump inhibitors and a smaller but steady increase of 38% in use of histamine H(2) antagonists; it is unlikely that much of the prescribing of anti-ulcer and antimicrobials was accurately targeted and rationally defensible. (3) More positively, use of beta(2)-agonist inhalers increased by 45% despite a 254% increase in the use of inhaled steroids. Use of HRT increased by 389% though evidence of under-use is given. There was a steady increase in the use of both insulins (28%) and oral hypoglycaemics (34%). The use of 'statins' (690%) and fibrates (123%) increased. (4) The possible interpretations and implications of these patterns of drug use is discussed, together with their potential as proxies for morbidity incidence in the community.

Journal Article↗
PubMed1996

Validation of a test of competence in transesophageal echocardiography.

OBJECTIVE: A test was developed that is based on intraoperative findings to evaluate knowledge of intraoperative echocardiography. This study examines the performance of attending anesthesiologists and residents at various levels of training in order to validate the test's ability to measure physician competence in intraoperative echocardiographic diagnosis. DESIGN: This study was a prospective evaluation of a test of competence in transesophageal echocardiography. SETTING: Two university medical centers. PARTICIPANTS: Volunteer anesthesia faculty and residents. INTERVENTIONS: The participants took an echocardiographic examination that consisted of 34 "K"-type multiple-choice questions and a 45-second video-loop sequence for each question. The video sequences were chosen for their high quality and unambiguous representation of both normal and pathologic images obtained by transverse transesophageal echocardiographic imaging. The questions were written by experienced echocardiographers. The test was administered to 25 individuals at two academic institutions: 11 residents with minimal transesophageal echocardiography exposure and 14 faculty who were relatively experienced with transesophageal echocardiography. All of the residents repeated the examination at the end of their third clinical anesthesia year, which included transesophageal echocardiography training. The differences between the groups' scores were analyzed using the Kruskal-Wallis test and Wilcoxon's rank-sum test. To correct for the multiple comparisons, p < 0.025 was deemed significant. MEASUREMENTS AND MAIN RESULTS. Before their transesophageal echocardiography training, the residents scored significantly lower than the faculty (p < 0.002). After 1 year of training, their scores significantly increased (p = 0.021), and their scores were not significantly different from the faculty level (p = 0.052). CONCLUSIONS: Test performance differed according to level of experience. This suggests that the test is a valid measure of intraoperative transesophageal echocardiography competence.

Anesthesiology↗
PubMed1994

A 'compass' for general practitioner prescribers.

This paper records the result of research and development in interrogating a general practitioner prescription pricing database to provide customised analysis for every practice. The system 'COMPASS' (Computerised On-line Monthly Prescribing Analysed for Science and Stewardship) is described, and identifies instances where each practice might improve cost-effectiveness and scientific rationality in prescribing. One hundred and two such instances are interrogated. This initial COMPASS report is then supplemented by screening the database to show a practice's: 1. range of drugs used--an excessive range should be discouraged. 2. use of drugs often used imprecisely--eg, antibiotics. 3. predicted prescribing cost--based on practice demography. 4. use of drugs with very limited GP value--eg, peripheral vasodilators. Northern Irish fundholding general practitioners are finding COMPASS valuable in planning improvement in cost-effectiveness and quality.

Cost Savings↗
PubMed1993

An integrated software system for quality assurance-related kappa coefficient analysis of intraoperative transesophageal echocardiography interpretive skills.

This report describes the development of a quality assurance-oriented integrated software system designed for an anesthesiology-based intraoperative transesophageal echocardiography service. Entry data include patient and operation demographics, two-dimensional echocardiographic, saline-contrast, and color flow/pulsed Doppler assessments of the heart and great vessels, presented in a defined sequence. A statistical analysis component (kappa coefficient analysis) allows for comparison of intraoperative real-time interpretations with laboratory interpretations made by experienced full-time echocardiographers on a field-by-field basis. This provides a means of quantifying expertise in each individual aspect of the patient examination sequence. We believe that such self-appraisal data are essential for delineating the status and tracking the progress of service being provided.

Echocardiography, Transesophageal↗
PubMed1993

A clinical computer database entry form for an intraoperative anesthesiology-based transesophageal echocardiography monitoring service.

Transesophageal echocardiography (TEE) has been increasingly applied to supplement and, in instances, to supplant conventional intraoperative cardiac monitoring. Our body of experience (> 1600 intraoperative TEE procedures), combined with insights gleaned from an intramural quality assurance study, and clinical implications of certain recent advances in the field, led us to develop the following TEE computer database entry form. The form, completed intraoperatively, consists of a patient and surgical procedure demographics section, followed by fields based on the TEE examination. The scans encompass transverse plane basal short axis, long axis, and transgastric views of the heart and great vessels. The two-dimensional echocardiographic, saline-contrast, color flow and pulsed Doppler data represent both right and left ventricular performance, valvular function and specific lesions. This database entry form is intended to serve as a guide for performance of a nominally complete intraoperative study and facilitate maintenance of a TEE archive consistent with current advances.

Anesthesia Department, Hospital↗
PubMed1993

Transesophageal two-dimensional echocardiographic analysis of right ventricular systolic performance indices during coronary artery bypass grafting.

Sixteen patients (aged 59 +/- 14 years) undergoing coronary artery bypass surgery were evaluated to delineate the intraoperative course of transesophageal echocardiographic right ventricular (RV) systolic performance indices. Pre-induction data included thermodilution RV ejection fraction (RVEFTD), 0.43 +/- 0.13, RV end-diastolic volume index (EDVI), 110 +/- 33 mL/m2, cardiac index (CI), 3.4 +/- 1.0 L/min/m2, RV end-diastolic pressure (EDP), 7.1 +/- 4.2 mmHg, and mean pulmonary artery pressure (PAP), 21 +/- 6 mmHg. Eleven patients had significant right coronary artery (RCA) disease (> 70% occlusion). Five patients arrived with an ongoing nitroglycerin infusion (1 to 3 micrograms/kg/min), which was maintained intraoperatively. Echocardiographic measurements included longitudinal-axis (LA) and short-axis (SA) planimetered area excursion fractions (2DLA and 2DSA, respectively) and LA maximal major and minor axis shortening fractions (max majorLA and max minorLA, respectively). Hemodynamic measurements included RVEFTD, EDVI, CI, EDP, and PAP. Measurements were determined following induction/endotracheal intubation, following sternotomy/pericardiotomy, and after cardiopulmonary bypass (CPB) with the chest open. All patients were maintained on vasodilator therapy post-CPB (nitroglycerin, 1 to 3 micrograms/kg/min [N = 16] and nitroprusside, 0.5 to 4.5 microgram/kg/min [N = 4]) post-CPB. Two patients received inotropic support (epinephrine, 0.2 to 0.3 microgram/kg/min). CPB was associated with significant decreases in max major axisLA and 2DLA (P < 0.05) as compared to measurements determined prior to CPB. Maximum major axisLA values pre-CPB were 0.35 +/- 0.06 and 0.33 +/- 0.08 versus post-CPB values of 0.24 +/- 0.08.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1993

The relationship between "normal" transesophageal color-flow Doppler-defined tricuspid regurgitation and thermodilution right ventricular ejection fraction measurements.

Twenty coronary artery revascularization patients, aged 58 +/- 15 years, were studied intraoperatively to define the impact of Doppler-defined tricuspid regurgitation on measurement of thermodilution right ventricular ejection fraction (50 msec response pulmonary artery catheter). Right ventricular function was also estimated using a measurement technique independent of flow patterns across the tricuspid valve (transesophageal two-dimensional echocardiographic 5.0 MHz phased-array transducer). Measurements included transverse plane long- and short-axis planimetered area ratio, respectively, and tricuspid annular plane systolic excursion ratio (ratio = end-diastolic minus end-systolic value divided by end-diastolic value). Data were expressed as thermodilution-echocardiographic gradients, ie, thermodilution ejection fraction minus long-axis planimetered area ratio, short-axis planimetered area ratio, and tricuspid annular plane systolic excursion ratio, respectively. Tricuspid regurgitation was quantified by color-flow Doppler perimetry of maximal regurgitation jet area and analysis of transduced right atrial pressure waveform. Doppler estimates were expressed as absolute values and as a function of corresponding atrial area (tricuspid regurgitation index = planimetered jet area divided by right atrial area). Data were obtained following endotracheal intubation, sternotomy, pericardiotomy, cardiopulmonary bypass, and chest closure. Data were evaluated by regression analysis, with separate analyses performed for each time period. Profiles were unassociated with right atrial pressure waveform abnormalities. There was no significant relationship between thermodilution ejection fraction variance values and tricuspid regurgitation jet area or regurgitation index, respectively. In each measurement period, thermodilution-echocardiographic gradients were also unrelated to the tricuspid regurgitation estimates.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization, Swan-Ganz↗
PubMed1993

Transoesophageal echocardiographic assessment of haemodynamic function during laparoscopic cholecystectomy.

We have measured cardiovascular changes associated with insufflation of carbon dioxide and the reverse Trendelenburg position during laparoscopic cholecystectomy, using transoesophageal echocardiography in 13 healthy patients. End-tidal carbon dioxide values increased after insufflation of carbon dioxide, with values significantly (P < 0.05) increased after lateral tilt positioning. Creation of a pneumoperitoneum was associated with increases (P < 0.05) in left ventricular end-systolic wall stress, concomitant with increases (P < 0.01) in peak airway pressure and systemic arterial pressure. In addition, left ventricular end-diastolic area decreased (P < 0.05) after reverse Trendelenburg positioning. Left ventricular ejection fraction was maintained throughout the study.

Adult↗
PubMed1993

Quality assurance for intraoperative transesophageal echocardiography monitoring: a report of 846 procedures.

We evaluated our experience with 846 consecutive transesophageal echocardiography (TEE) intraoperative monitoring procedures performed between November 1989 and July 1991. TEE frequency was 36 +/- 11 per month (range 16-55) and represented 69.8% of cardiac valve surgery cases, 40.2% of coronary artery bypass graft cases, and 2.2% of total operative caseload. Major patient complications consisted of transient vocal cord paresis and ingestion of glutaraldehyde-disinfectant solution. Minor complications consisted of a chipped tooth (one case) and pharyngeal abrasions (three cases). The Quality Assurance (Q/A) Program evaluated both record keeping and quality of imaging, as judged by cardiologist echocardiographer reviewers. The percentage of completion for each Q/A indicator was as follows: medical record documentation, 88%; database form annotation, 94%; and provision of videotape recording, 91%. TEE database forms were analyzed further in terms of the percentage of fields completed. Completion scores were 73%. The following scoring system was utilized for videotape evaluation by the cardiologists: 1 = excellent; 2 = good; 3 = poor. The median grade for both two-dimensional echocardiography and color flow Doppler (CFD) examinations was 2. Poor quality images (grade 3) were present in 15.2% of two-dimensional echocardiography and 20.3% of color flow Doppler examinations, and disproportionately associated with 4/26 attendings. Supplemental audit of the cardiology reviewers performance demonstrated 569/846 videotapes showed no objective evidence of review. The cardiology reviewer forms of the remaining 277 videotapes were evaluated in terms of the percentage of fields completed. The completion score was 56%. These data suggest the need for formal Q/A for intraoperative TEE, both for anesthesiologists and reviewing cardiologists.

Echocardiography↗
PubMed1992

Thermodilution right ventricular ejection fraction measurement reproducibility--a study in patients undergoing coronary artery bypass graft surgery.

OBJECTIVE: To assess the effects of heart rate, right ventricular systolic performance (ejection fraction), chamber dimensions, and flow rate (cardiac index) on the reproducibility of algorithm-derived triplicate thermodilution right ventricular ejection fraction measurements. DESIGN: Prospective study; combined hemodynamic and echocardiographic clinical evaluation. SETTING: Operating room in a university hospital. PATIENTS: Twenty-one coronary artery bypass graft patients. MEASUREMENTS AND MAIN RESULTS: The right atrial delivery site was positioned by analysis of transduced pressure waveform and echocardiographic imaging of tracer agitated saline cavitations. Measurement reproducibility was quantified by determining the variation (standard deviation) within 101 triplicate thermodilution measurement sets. There was no significant relationship between measurement reproducibility and estimates of right atrial area (21.6 +/- 6.9 cm2), diameter (5.1 +/- 0.8 cm) and supero-inferior length (5.1 +/- 0.9 cm) and right ventricular maximal minor axis diastolic diameter (4.21 +/- 1.05 cm). Reproducibility was also unrelated to right ventricular end-diastolic volume index (97.9 +/- 32.7 mL/m2) and cardiac index (2.9 +/- 0.9 L/min/m2). Measurement reproducibility was directly related to mean right ventricular ejection fraction (0.39 +/- 0.14) and inversely related to heart rate (80.8 +/- 18.6 beats/min) (p < .01 and < .001, respectively). CONCLUSIONS: Thermodilution-derived right ventricular ejection fraction measurement reproducibility was unrelated to estimates of right atrial and ventricular dimensions and cardiac index. Measurement reproducibility was a direct function of right ventricular systolic performance and an indirect function of heart rate. Measurement should be interpreted with these constraints in mind.

Adult↗
PubMed1992

Transesophageal color flow Doppler imaging for aortic insufficiency in patients having cardiac operations.

Transesophageal color flow Doppler findings were studied in 30 patients with aortic insufficiency who had cardiac operations. Measurements were expressed as ratios of corresponding left ventricular outflow tract dimensions. Regurgitant jet proximal width ratio was significantly related to jet area ratio (r = 0.92) and correlated poorly with the degree of jet penetration into the left ventricular cavity (r = 0.32). The vectors of the regurgitant jets were variable. Nine patients had undergone aortography. Regurgitant jet proximal width and area ratios were significantly related to angiographic grade (r = 0.88 and 0.87, respectively) in these patients. We concluded that the esophagus offers a satisfactory transducer orientation for color flow Doppler assessment of aortic insufficiency.

Adult↗
PubMed1992

Transesophageal echocardiographic evaluation of aortic valve integrity with antegrade crystalloid cardioplegic solution used as an imaging agent.

Forceful intravascular injection of crystalloid causes microbubble (cavitation) formation. The resulting ultrasound-opaque medium is widely used in echocardiography as a source of contrast. The following study was performed to determine the feasibility of using antegrade crystalloid cardioplegic solution as a transesophageal two-dimensional echocardiographic imaging agent to evaluate aortic valve integrity. In patients with preexisting aortic regurgitation (n = 12), cardioplegic solution administration (driving pressure 150 to 200 mm Hg) was associated with the appearance of intracardiac cavitations in 12 of 12 patients. Among patients without preexisting valve dysfunction (n = 22), intracardiac cavitations were manifested in 20 of 22, with extension of the cavitations to the left atrium in 17. Associated cardiac dimensions (left ventricular outflow tract area and left ventricular diameter) did not exceed preceding cardiopulmonary bypass values in these patients (2.0 +/- 1.6 cm2 versus 2.6 +/- 1.2 cm2 and 1.4 +/- 0.7 cm versus 1.5 +/- 0.8 cm, respectively). It was concluded that antegrade crystalloid cardioplegic solution can be used as an echocardiographic contrast agent in this context. The inability to establish a relationship between the extent of cardioplegic intracardiac penetration and left ventricular dimensional changes limits the technique, as presently employed, to qualitative analysis of valve dysfunction.

Adult↗