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Biomedical subjects

D H Bennett

Publications and source records attributed to D H Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Closure of large psychiatric hospitals in England].

Contrary to the procedure followed in German-speaking countries, British national health policy since the fifties has been to promote and actively effect the closure and winding up of large psychiatric hospital centres in favour of alternative structures. The present article presents a preliminary balance sheet on 39 hospitals that have been closed since 1961 to the present day in the course of this shift-in-emphasis policy.

Community Mental Health Services↗
PubMed1994

The hospital cost (fiscal year 1991/1992) of a simple perioperative allogeneic red blood cell transfusion during elective surgery at Duke University.

We sought to determine the actual cost to Duke University Medical Center of a perioperative red blood cell transfusion. A recent audit at Duke University Medical Center determined the base average direct and indirect hospital costs for providing a unit of red blood cells. The Transfusion Service's base cost for providing an allogeneic unit of red blood cells was $113.58. To obtain the actual hospital cost of transfusing a unit of red blood cells in the perioperative period, associated costs were calculated and added to the Transfusion Service's base cost. These associated costs included compatibility tests on multiple units per each unit transfused in the perioperative period, performing ABO and Rh typing and antibody screening on samples from patients who were not subsequently transfused, compatibility tests on units not issued, handling costs of units issued but not used, physically administering the blood, and the cost of the recipient contracting an infectious disease or developing a transfusion reaction. These associated costs increased the cost of transfusing an allogeneic unit of red blood cells in the perioperative period to $151.20. Perhaps the techniques described in the study can be used to quantify cost/benefit ratios associated with future changes in transfusion practice.

Blood Banks↗
PubMed1993

Late symptom recurrence after successful coronary angioplasty: angiographic outcome.

OBJECTIVES: To determine the angiographic appearance of the dilated coronary artery and the cause of symptoms in patients who presented with a return of chest pain more than 1 year after successful percutaneous transluminal coronary angioplasty (PTCA). DESIGN: Retrospective analysis of coronary angiograms and review of case histories. PATIENTS AND METHODS: 112 patients who underwent repeat coronary arteriography for investigation of chest pain 13-105 (median, 30) months after successful coronary angioplasty were studied. All patients were free of symptoms for at least 12 months after the initial angioplasty. RESULTS: A return of chest pain was attributed to restenosis in 12 patients (11%), to a new lesion or worsening of pre-existing coronary lesion in 56 patients (50%), and to both restenosis and stenosis in non-dilated coronary segments in 10 patients (9%). There was no restenosis in 112 of the 134 dilated lesions (84%). In 34 patients (30%), there was no significant stenosis in either dilated or non-dilated coronary segments. CONCLUSIONS: In patients undergoing coronary angiography for the investigation of recurrent chest pain more than 1 year after successful coronary angioplasty, the majority of dilated coronary segments had a good angiographic appearance. Late onset angina following PTCA is usually due to new coronary lesions or worsening of pre-existing mild stenosis.

Angina Pectoris↗
PubMed1993

Cardiomyopathy secondary to sinus tachycardia.

We describe a case of cardiomyopathy resulting from a tachycardia of high-right atrial origin indistinguishable from sinus tachycardia. The symptoms and angiographic appearances improved dramatically with beta blockade.

Adult↗
PubMed1993

Catheter ablation of the atrioventricular junction by radiofrequency energy delivered across the interventricular septum using a left sided approach.

We describe seven successful cases of ablation of the atrioventricular (AV) junction by passing radiofrequency (RF) energy between the tip of an electrode on the left ventricular aspect of the interventricular septum and a further electrode on the right side of the His bundle. All had undergone unsuccessful attempts at conventional unipolar RF ablation from the right and left side of the heart.

Aged↗
PubMed1993

Use of a remotely controlled mechanical pump for coronary arteriography: a study of radiation exposure and quality implications.

BACKGROUND: Exposure to radiation is a hazard of invasive cardiology. To minimise the risk it is essential to keep the doses received as low as possible. AIM: To assess the effect on cardiologist radiation exposure and the quality of coronary artery opacification of the use of a remotely controlled mechanical pump for coronary arteriography. A secondary aim was to assess any disadvantages and safety. METHODS: 319 patients were randomised to have coronary arteriography carried out with contrast injected either by hand or by a remotely controlled mechanical pump. Six cardiologists participated: two catheter laboratories were used and both brachial and femoral approaches were included. The exposure of the cardiologists to radiation was assessed by film badge dosimetry. The badges were worn on the hat. The total time for the procedure, screening time, the dose-area product meter reading, and any complications were recorded for each examination. The quality of arterial opacification was reported on a scale of 0-5. RESULTS: The mean radiation dose per procedure was 0.011 mSv for hand injection of contrast and 0.005 mSv for mechanical injection (p < 0.01). There were no differences in procedure times or screening times. There were no complications attributable to mechanical injection. Arterial opacification was not significantly different in the two groups (4.01 v 4.03 for the left coronary artery, 4.68 v 4.78 for the right coronary artery). The right coronary artery was consistently better opacified than the left by both techniques (4.59 v 3.89, p < 0.001). CONCLUSIONS: Use of a remotely controlled mechanical pump for coronary arteriography reduced cardiologist radiation exposure by half. It was not associated with any inconvenience, expense, or complications and produced arterial opacification at least as good as injection by hand.

Cardiology↗
PubMed1993

Home ranges of feral cats at Avonmouth Docks (United Kingdom).

The feral cat population at a 178 ha dockland site was studied for eighteen months using direct observation assisted by radio-tracking. Though food appeared to be abundant and widely distributed, the population density was low (10-15 adults/km2). Home ranges were similar for males and females, and were much smaller (15 +/- 17 ha and 10 +/- 7 ha, respectively) than would be expected from the low density. The implications of the findings for feral cat control were discussed, with particular emphasis on rabies emergency measures.

Animals↗
PubMed1992

Reduction of radiation exposure to the cardiologist during coronary angiography by the use of a remotely controlled mechanical pump for injection of contrast medium.

Selective coronary cineangiography was carried out in 103 consecutive patients. In half the examinations (53) injection of contrast medium was performed by hand using a syringe, with the cardiologist standing in the usual position next to the X-ray table. In the other half (50) contrast medium was injected by a remotely controlled mechanical pump whilst the cardiologist stood well away from the X-ray source. Radiation dose to the lens of the cardiologists eye was estimated for the two groups by measurement of head badge dosimetry. In the first group (hand injection) total radiation dose was 1.30 mSv; in the second group (mechanical injection) it was reduced five-fold, to 0.25 mSv. This technique therefore represents an important means of achieving substantial reductions in radiation exposure to cardiologists.

Cineangiography↗
PubMed1992

Acute and chronic performance of a steroid eluting electrode for ventricular pacing.

Studies have demonstrated consistently low stimulation thresholds in the first months following implantation of steroid eluting electrodes. There have been no reported cases of exit block. There is little information on the long-term performance of these leads. Data were collected on 15 patients in whom Medtronic steroid eluting leads (5023 and 4003) had been implanted in 1987. Stimulation thresholds were measured at implantation and at weeks 1, 2, 3, 4, 5, 6 and 12. Stimulation threshold, lead impedance and sensing thresholds were monitored periodically for 3 yr using the telemetered function of the pulse generator. Three-month follow-up was obtained in all the patients and 3-yr follow-up in 10. Stimulation thresholds remained low throughout the follow-up period in all but one patient who developed exit block necessitating the replacement of the pacing system. In the remaining patients there was a significant increase in mean stimulation threshold from implantation to week 1 (mean stimulation threshold at implantation = 0.106 ms, mean ST at week 1 = 0.182 ms; p = 0.05), and also a gradual increase in the stimulation threshold over the first 2 yr of follow up (mean stimulation threshold 1 week = 0.182 ms, mean stimulation threshold months 13-24 = 0.243 ms; p = 0.05). Lead impedance showed no significant change over the follow-up period (mean change in impedance = 4.3 omega, SD 163.2, p = 0.97). Unlike many conventional electrodes, steroid eluting leads show no early peak in stimulation threshold but exit block can occur. Stimulation thresholds show a small but significant rise over time.

Atrial Fibrillation↗
PubMed1992

Atrial latency in a dual chambered pacing system causing inappropriate sequence of cardiac chamber activation.

A transvenous atrioventricular pacemaker was implanted in a patient in whom junctional bradycardia and recurrent ventricular tachycardia had occurred after coronary artery bypass surgery. The period between delivery of the atrial stimulus and resultant atrial excitation was prolonged by up to 0.22 seconds and exceeded the programmed delay between atrial and ventricular stimulation. Consequently, ventricular stimulation preceded atrial excitation. Cardiac failure resulted: it was resolved by reprogramming the pacemaker to the atrial inhibited mode.

Atrial Function↗
PubMed1992

[What must the community contribute to the managements of chronic psychiatric patients?--Reflections from England].

Chronically disabled psychiatric patients who are living outside hospital still need help. The degree of disability they show and the support which they receive from family or friends differs greatly. How they manage will depend on their ability to adapt and one can recognize the difference between those who adapt well in spite of disability and those for whom this is very difficult. In consequence their need for support from others varies. In England some national voluntary agencies traditionally offer support. However, today the combined work of voluntary organisations, hospitals and statutory community authorities in local areas is often impressive and two examples are described. Even so families are perhaps still the most important form of support although some are unable or unwilling to help. Other alternative forms of help noted are two-patient marriages, long-term hospital support of discharged patients and regular employment. Examples of innovations in Australia and the U.S.A. are also described.

Chronic Disease↗