Search PubMed⌕ Search

Biomedical subjects

A M Jenkins

Publications and source records attributed to A M Jenkins.

At least 37 records · Page 2Linked to original sources
PubMed1993

Pressure natriuresis following therapy for "one-clip one-kidney" hypertension in man.

Decreased renal tubular reabsorption of sodium in response to increased renal artery perfusion pressure, or "pressure natriuresis", has been demonstrated directly in animal experiments but not in man. In bilateral or single-kidney renovascular hypertension, hypertension has been attributed to reduced pressure natriuresis, and a similar mechanism may operate in chronic renal failure. We report a patient who presented with bilateral renovascular disease and was treated initially by unilateral nephrectomy. At a second operation the remaining ischemic kidney was revascularised. There followed a dramatic natriuresis, sufficient to cause clinical and biochemical features of hypovolemia. However, despite the natriuresis, systemic blood pressure remained elevated in the few weeks following surgery. We attribute the natriuresis to increased renal artery perfusion pressure, and conclude that acute pressure natriuresis sufficient to over-ride neurohormonal antinatriuretic mechanisms does occur in man. However, the failure to normalize blood pressure acutely following the natriuresis suggests that decreased sodium excretion is not the only mechanism which maintains hypertension in this unusual syndrome.

Adult↗
PubMed1993

Above-knee femoropopliteal bypass grafts and the consequences of graft failure.

In all, 290 femoral to above-knee popliteal artery bypasses were performed between January 1983 and September 1991. PTFE grafts were used in 113 cases (39%) and vein grafts in 177 (61%) (reversed in 146 cases and in situ in 31). Patients were followed up for a median time of 20 months. The 2-, 4- and 6-year patency rates for vein and PTFE grafts were 70%, 62% and 57%, respectively, compared with 58%, 46% and 41% (no statistical difference in survival curves, P = 0.2). The 2-, 4- and 6-year limb salvage rates were 82%, 78% and 62% compared with 75%, 64% and 58% (no statistical difference in survival curves, P = 0.6). A total of 99 grafts occluded during follow-up (45 PTFE and 54 vein grafts). Major amputation was required in 63 limbs; below-knee in 37 limbs (59%), and above-knee in 26 limbs (41%). There was no statistical difference in the amputation level with respect to the graft type. Final healing at the below-knee level was achieved in 23 of 35 (66%) failed vein grafts and in 14 of 28 (50%) failed PTFE grafts.

Adult↗
PubMed1991

Reoperations for late complications following abdominal aortic operation.

Fifty patients were identified who, following abdominal aortic operation, developed late complications affecting the vascular graft or endarterectomy and who underwent their first reoperation between 1979 and 1989. Thrombosis was the commonest complication affecting 28 (56 per cent) patients, followed by false aneurysm in 11 (22 per cent), enteric fistula in nine (18 per cent) and graft infection in two (4 per cent). The 30-day mortality rate for reoperation was 8 per cent; longer follow-up revealed mortality rates of 22, 50 and 63 per cent at 1, 3 and 5 years respectively. Thirty-four complications required reoperation within 5 years of the original surgery. Reoperation was needed for 35 patients whose original pathology was occlusive disease and for 15 whose original pathology was aneurysm. The nature of the complication was related to initial pathology; thrombosis was far commoner in those with occlusive disease, and enteric fistula and false aneurysm were commoner in those with aneurysmal disease.

Adult↗
PubMed1991

Ruptured aortic aneurysm: a proposed classification.

There is a wide variation in reported operative mortality rates for ruptured abdominal aortic aneurysm, ranging from 14 to 70 per cent. Although many factors influence this variation, such as the expertise and facilities available at an individual institution, considerable differences could be due to variations in the pattern of referral and the proportion of cases accepted for operation. In this paper a classification applicable to all patients with ruptured aortic aneurysm is proposed; it has been applied prospectively to 100 consecutive patients with ruptured abdominal aortic aneurysm referred to the Edinburgh Vascular Surgical Unit. The classification illustrates how surgical mortality rates ranging from 29 to 52 per cent may be reported using the same mortality data. Two major benefits may derive from the use of such a standard reporting system. Firstly, it allows management deficiencies to be identified easily and, secondly, it should facilitate comparison of results reported from different centres.

Age Factors↗
PubMed1991

Transcranial Doppler monitoring during carotid endarterectomy.

Transcranial Doppler monitoring of the middle cerebral artery blood flow velocity was used as an adjunct to routine methods of cerebral monitoring in a prospective study of 30 consecutive patients undergoing carotid endarterectomy to investigate whether transcranial Doppler monitoring provided information influencing operative technique. Application of carotid clamps caused a significant fall in middle cerebral artery velocity and there was a linear relationship between middle cerebral artery velocity and internal carotid artery stump pressure. Assuming a stump pressure of less than 50 mmHg to be an indication for shunting, this would correspond to a systolic middle cerebral artery velocity of less than 42 cm/s and a mean velocity of less than 30 cm/s. Transcranial Doppler monitoring immediately identified problems with shunt function and demonstrated a higher frequency of intraoperative embolization than had been anticipated, particularly after shunt insertion and final restoration of flow. With revision of operative technique this phenomenon is rarely encountered now. Two of the 30 patients exhibited a minor neurological deficit on recovery of consciousness, and transcranial Doppler monitoring was able to identify the probable underlying cause in both cases. Unnecessary and potentially hazardous re-exploration was avoided. In the absence of transcranial Doppler monitoring the neurological deficit in one of the patients might have been much worse.

Blood Flow Velocity↗
PubMed1990

Traumatic aneurysm of the extracranial internal carotid artery due to hyperextension of the neck.

Aneurysms of the extracranial internal carotid artery (ICA) are rare. The majority arise iatrogenically after surgery, but a few follow trauma. Traumatic aneurysms of the ICA may follow penetrating injury, direct "blunt trauma" injury or hyperextension of the neck. We report a case of traumatic ICA aneurysm which probably followed a hyperextension injury to the cervical spine in a young woman.

Adult↗
PubMed1990

Bacteriology of aortic aneurysm sac contents.

Aerobic and anaerobic cultures from the intraluminal thrombus of infrarenal aortic aneurysms were obtained from 239 patients. Culture results were related to the mode of presentation and the incidence of graft infection. Positive cultures were obtained from 27 patients (11.3%). No statistical correlation between the result of thrombus culture and the mode of presentation was found.

Aorta, Abdominal↗
PubMed1989

Acute ischaemia of the upper limb compared with acute lower limb ischaemia; a 5-year review.

A series of 61 patients with acute upper limb ischaemia treated over a 5-year period is analysed and compared with patients presenting with acute lower limb ischaemia during the same period. The mean age was 74 years with a female to male ratio of 2.2:1. Eighty-two per cent were treated by operation. Three patients died and no survivors required a major or minor limb amputation, in contrast to a 5 per cent major limb amputation rate in patients with acute lower limb ischaemia. Mortality for upper limb ischaemia was 5 per cent compared with a 30 per cent mortality rate in patients with acute lower limb ischaemia in whom cardiopulmonary debility (New York Heart Association score 3-4) was significantly greater.

Acute Disease↗
PubMed1989

Acute ischaemia of the lower limb: the effect of centralizing vascular surgical services on morbidity and mortality.

Surgical audit data for two 5-year periods (1974-78 and 1983-87) have been compared in a Health Board Area to assess the impact of centralization of emergency vascular services on the treatment of the acutely ischaemic lower limb. Patient populations in each period were comparable. Mortality rates remained constant in both periods at approximately 30 per cent. A significant improvement in overall limb salvage was observed (from 54 to 67 per cent, P less than 0.05). Limb salvage in survivors was improved from 80 to 95 per cent (P less than 0.001) and was paralleled by an increase in the number of reconstructive vascular procedures performed. We concluded that the centralization of emergency vascular services has not led to a reduced risk of mortality but has been associated with improved limb salvage.

Acute Disease↗
PubMed1989

Ten-year review of non-ruptured aortic aneurysms.

Between 1978 and 1987, 587 cases of abdominal aortic aneurysm were operated on in the Vascular Unit of the Royal Infirmary of Edinburgh. Over this ten-year period there was a dramatic increase in the number of patients treated. Rupture had occurred in 278 patients. Of the 309 patients with non-ruptured aneurysm 175 were asymptomatic, 84 were symptomatic and 50 were acutely symptomatic. Two hundred and fifty-nine patients underwent elective operation and the 50 acutely symptomatic patients were operated on as emergencies. The overall mortality for the non-ruptured series was 2.9 per cent. The mortality in patients undergoing elective surgery was 1.9 per cent (1.1 per cent in asymptomatic and 3.6 per cent in symptomatic patients) and 4.0 per cent for patients undergoing emergency surgery.

Adult↗
PubMed1989

Accuracy of interpretations of emergency department radiographs: effect of confidence levels.

We conducted a prospective study to assess the relationship between the interpretive agreement rate for emergency department radiographs and the degree of interpretive confidence. We hoped to identify a subset of ED radiographs that did not require mandatory review by a radiologist. For each of the 1,872 plain radiographs studied, emergency physicians assigned a confidence level to the interpretation before comparing it with the radiologist's dictated report. A second radiologist was consulted to resolve disagreements. The overall rate of interpretive agreement was 94.6%. Agreement varied significantly (P less than .001) as a function of confidence level and by type of radiograph, but not by training level. Agreement varied significantly (P less than .001) as a function of confidence level for some types of radiographs (eg, chest, extremities) and for some types of radiographic findings (acute positive). No subset of radiographs had 100% agreement. Treatment was potentially altered in 38 patients as a result of the interpretive disagreement that occurred in 2% of studied radiographs. We conclude that the interpretive agreement rate increases in relation to interpretive confidence but that confidence levels cannot safely exclude certain radiographs from mandatory review by a radiologist.

Emergency Medicine↗
PubMed1989

Morbidity and mortality in acute lower limb ischaemia: a 5-year review.

A series of 204 consecutive patients with acute lower limb ischaemia was treated over a 5-year period in a Regional Vascular Unit. The mean age was 70 years, with a range of 41-98 and a female to male ratio of 1:0.94. Eighty-eight percent were treated by operation. Twenty-one had simultaneous vascular reconstructive procedures. Fifty-three patients died within 30 days (mortality rate 26%), and 12 required major amputation. Of these, four died resulting in a limb salvage rate of 95% in the survivors. An analysis of factors affecting outcome has shown increasing age, level of occlusion, recent myocardial infarction, pre-existing peripheral arterial disease and cardiopulmonary functional class to be major determinants of morbidity and mortality.

Adult↗
PubMed1988

Effect of metoclopramide, bethanechol and the cholecystokinin receptor antagonist, L-364,718, on gastric emptying in the rat.

The prokinetic effects of metoclopramide, bethanechol and L-364,718 on a semisolid meal and solid pellet gastric emptying were evaluated and compared. Each compound increased the rate of meal emptying as measured 90 min post-dose. L-364,718, a non-peptide CCK antagonist, was the most potent of these three agents with statistically significant activity observed at 0.03, 0.1 and 0.3 mg/kg p.o. Only metoclopramide significantly enhanced pellet emptying in a dose-dependent manner (3-30 mg/kg p.o.). The effects of each test agent and the potential physiologic role of cholecystokinin in regulating gastric emptying are discussed.

Animals↗