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Biomedical subjects

R H Gregson

Publications and source records attributed to R H Gregson.

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

Eye splashes during invasive vascular procedures.

In recent years there has been an increased awareness among health care workers regarding possible risk of nosocomial transmission of blood borne pathogens. The aim of this study is to document the risk of contamination of radiologists' eyes during invasive vascular procedures. Radiologists performing these examinations were asked to wear glasses throughout. After each examination the glasses were inspected for droplets. 150 procedures were performed on 123 patients (M = 80, F = 43). 10 procedures (6.7%) resulted in splashes to glasses. In four of these cases the radiologist was not aware of the "eye splash" nor was there a spray event to account for it. Radiologists were aware of 13 spray events (8.7% of all procedures). There was a significantly increased risk of spray events and eye splashes during thrombolysis (chi 2 = 14.93, p < 0.001) and of spray events during angioplasty when compared with perfemoral arteriography (chi 2 = 8.816, p < 0.01). Procedures lasting longer than 30 min were associated with a significantly increased risk of spray events (chi 2 = 5.63, p < 0.02). Significantly more eye splashes were associated with more than two catheter changes (chi 2 = 8.912, p < 0.01). It is suggested that protective eye wear should be used routinely during invasive vascular procedures.

Angiography↗
PubMed1994

Experience with pulse-spray technique in peripheral thrombolysis.

Pulse-spray thrombolysis (PST) is a new technique of accelerated peripheral arterial thrombolysis. This technique has been evaluated on 24 patients with limb ischaemia. Severe acute limb-threatening ischaemia with sensory and motor deficit was present in 11/24 (45.8%) patients. The median dose of recombinant tissue plasminogen activator (rt-PA) used was 18 mg (10-35 mg) injected in a concentration of 0.33 mg/ml and bolus size of 0.2 ml. The median length of occlusions treated was 23 cm (range 4-55 cm). Complete initial lysis was achieved in 23/24 (95.8%) and limb salvage at 30 days was achieved in 18/24 (75%) of the cases. The overall 30-days mortality was 4/24 (16.6%) and 2/4 (50%) in those who required surgical intervention. The median duration of thrombolytic treatment was 137.5 minutes (range 35-1125 minutes) which is an 11-fold and significant reduction (p < 0.001, Mann-Whitney) in lysis time compared with the results of conventional low dose infusion of rt-PA at a rate of 0.5 mg/h in 120 consecutive patients in our unit. PST rapidly restores vascular patency and may become the treatment of choice for acute limb ischaemia including those at immediate risk of irreversible ischaemic injury which would not be considered suitable for conventional thrombolysis.

Adult↗
PubMed1994

Congenital hypertrophy of the retinal pigment epithelium and mandibular osteomata as markers in familial colorectal cancer.

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) and multiple mandibular osteomata are markers of familial adenomatous polyposis (FAP). We have assessed their prevalence in non-polyposis familial colorectal neoplasia. Multiple mandibular osteomata were present in 1/29 (3%) patients with familial colorectal neoplasia. CHRPE was present in 11/33 (33%) patients with familial colorectal neoplasia compared with 3/36 (8%) with sporadic disease (P = 0.01) and 4/32 (12.5%) control subjects (P = 0.04). Seven patients with familial colorectal neoplasia had multiple areas of CHRPE compared with one with sporadic disease (P = 0.02) and one control subject (P = 0.02). There was no obvious correlation between calculated familial colorectal cancer risk and the presence of multiple areas of CHRPE. A proportion of patients with familial colorectal cancer have a marker found in FAP and may therefore have a constitutional genetic defect, at least in part responsible for their cancer, making them an interesting group for genetic study. Ophthalmoscopy may contribute to risk assessment in familial colorectal cancer.

Adult↗
PubMed1993

Peripheral arterial thrombolysis: intermediate-term results.

To determine the intermediate-term results of intra-arterial thrombolysis, 127 consecutive patients receiving 129 courses of treatment were reviewed at a median follow-up of 3 years. At initial review, 30 days after treatment, thrombolysis was successful in 63 cases (49 per cent). Of these patients, 16 were lost to follow-up: 15 died without further vascular symptoms and one moved from the area. Some 35 patients were alive and asymptomatic, of whom 33 had either angiographic or clinical evidence of continued arterial patency. Symptomatic reocclusion occurred in 12 cases; a further two patients remained asymptomatic and reocclusion was detected at follow-up. Two of the 12 symptomatic patients required amputation. Estimated patency rates were 80 per cent at 1 year, 72 per cent at 2 years and 70 per cent at 3 years. The intermediate-term results in the 66 cases in which lysis was unsuccessful were worse, only 16 patients (24 per cent) surviving to follow-up with the treated limb intact. It is concluded that, if thrombolysis is successful at 30 days, the intermediate-term results are good.

Adult↗
PubMed1993

The role of angiography in the investigation of acute or chronic gastrointestinal haemorrhage.

We have reviewed the clinical details and radiology of all patients with non-variceal gastrointestinal haemorrhage referred for angiography during an 8 year period. Forty-six patients with a history of overt bleeding had 49 technically satisfactory angiograms of which 29 were true positives but 16 were false negatives (sensitivity 64%, accuracy 63%). The accuracy of angiography in this group was much higher (92%) in those patients referred within 24 h of admission. Nine patients who had a history of iron-deficiency anaemia due to sub-acute blood loss had 9 angiograms. Five studies in this group were correct (two true negatives and three true positives) but there were four false positive studies. Angiography is an effective means of diagnosis in patients with acute gastrointestinal haemorrhage who have a negative endoscopy but best results will only be achieved when the study is performed with minimal delay following negative endoscopy. Angiography should also be considered in patients with continuing subacute blood loss when other investigations are negative.

Acute Disease↗
PubMed1992

Recombinant tissue-type plasminogen activator is superior to streptokinase for local intra-arterial thrombolysis.

The results of local intra-arterial thrombolysis in 98 patients treated with streptokinase and 69 patients treated with recombinant tissue plasminogen activator (rtPA) have been compared. The two groups of patients were well matched and their treatment protocols were identical except with regard to the thrombolytic agent used. Strict criteria for defining successful thrombolysis were used. Successful lysis was achieved in 40 of 98 patients (41 per cent) receiving streptokinase and 40 of 69 patients (58 per cent) receiving rtPA (P less than 0.05). The time to lysis was significantly shorter with rtPA, median time 22 h, than with streptokinase, median time 40 h (P less than 0.002). There was no difference in the incidence of haemorrhagic complications. These results suggest that rtPA is superior to streptokinase for local intra-arterial thrombolysis.

Adult↗
PubMed1991

Randomized trial of intra-arterial recombinant tissue plasminogen activator, intravenous recombinant tissue plasminogen activator and intra-arterial streptokinase in peripheral arterial thrombolysis.

Sixty patients were recruited into a randomized parallel group comparison of three thrombolytic regimens for acute or subacute peripheral arterial thrombosis. There were no significant differences in age, duration of history, length of occlusion or presence of neurosensory deficit between the groups. Initially successful lysis was significantly greater with intra-arterial (IA) recombinant tissue plasminogen activator (rt-PA) than with either streptokinase (Sk) (P less than 0.04) or intravenous (IV) rt-PA (P less than 0.01). The duration of therapy varied from a median of 35 h with IA rt-PA to 40 h with Sk (P greater than 0.5). The median (confidence interval) increase in ankle:brachial pressure index following IA rt-PA of 0.57 (0.33-0.82) was significantly higher than for either Sk of 0.24 (0-0.57) or for IV rt-PA of 0.18 (0-0.41). Limb salvage at 30 days was achieved in 80, 60 and 45 per cent respectively for IA rt-PA, Sk and IV rt-PA. Haemorrhagic complications occurred in six patients following Sk and in 13 following IV rt-PA; only one minor haemorrhage occurred following a catheter perforation in a patient who received IA rt-PA (P less than 0.05). IA rt-PA provides a more effective, safer fibrinolytic regimen than conventional therapy with Sk. IV rt-PA has not been as successful and carries a significantly higher risk of haemorrhagic complications.

Aged↗
PubMed1990

Tissue plasminogen activator in peripheral arterial thrombolysis.

Thirty acute peripheral arterial thromboses in 28 patients were treated with local low-dose intra-arterial recombinant tissue plasminogen activator (t-PA). All patients received 0.5 mg h-1 t-PA and 15 also received 250 units h-1 of intra-arterial heparin. Overall limb salvage at 30 days was 83 per cent (25 out of 30 limbs). Mean(s.d.) ankle/brachial index was increased by 0.53(0.26) and there was no significant difference between the group receiving t-PA alone and that receiving t-PA and heparin. No strokes or major haemorrhages occurred but there were four (13 per cent) minor haematomas associated with the catheter entry site. There were four (13 per cent) deaths from myocardial infarction occurring between 5 and 21 days after treatment. Rethrombosis occurred in four cases (13 per cent). In two patients following t-PA alone, rethrombosis occurred after 2 and 11 days. Limb salvage was achieved with a successful repeat thrombolysis and a femoropopliteal graft respectively. Rethrombosis after t-PA and heparin occurred after 30 days in two patients due to poor run-off and extensive proximal atheromatous disease respectively. t-PA is a safe, effective thrombolytic agent when given as a low-dose intra-arterial infusion. The addition of low-dose heparin does not produce any significant benefit.

Acute Disease↗
PubMed1990

The impact of the M1 air crash on the radiological services at the Queen's Medical Centre, Nottingham.

Following the M1 air crash on 8 January 1989, 39 casualties were taken to the Queen's Medical Centre, Nottingham. A team of 31 radiographers and four radiologists used all five X-ray rooms adjacent to the Accident and Emergency Department. Patients with head and spinal injuries were further assessed in the CT suite by four radiographers and a neuroradiologist. The volume of work in the first few hours and in the subsequent days is described. All radiological examinations have been reviewed and the injuries, including those missed at initial assessment, are discussed. The role of the radiologists was to issue immediate reports, manage examinations so as to minimize any delay and assess the need for further specialized investigation. Important problems were identified, specifically: the call-out system; patient deterioration and lack of resuscitation equipment; patient flow; documentation; radiology equipment; and missed injuries. These problems are discussed and recommendations are made for X-ray Departments in dealing with disasters.

Accidents, Aviation↗
PubMed1989

Acute peripheral arterial ischemia: a prospective evaluation of differential management with surgery or thrombolysis.

In this three year prospective study of 177 patients with acute peripheral arterial ischemia those subjects with acute iliofemoral emboli or ischemia with a neurosensory deficit had urgent operations. The remainder included patients less likely to have limb salvage after surgery and who therefore were treated with thrombolytic therapy. This was done in three open studies of intravenous, acylated, plasminogen-streptokinase activator complex, low dose intraarterial streptokinase and intraarterial tissue-plasminogen activator (t-PA). The overall outcome after 30 days of thrombolytic therapy was limb salvage (55%), amputation (15%), and death (30%). The severity of the presenting ischemia was the most important prognostic indicator. In patients with a neurosensory deficit, limb salvage after either embolectomy or surgical reconstruction (59%) was more likely than after thrombolysis (31%). In patients without a neurosensory deficit, limb salvage after thrombolysis (68%) was better, though not significantly, than after surgery (53%). Local intraarterial thrombolysis with either streptokinase or t-PA produced an encouraging 66% limb salvage in 59 cases. In management of acute peripheral arterial occlusions an approach based on the severity of ischemia is optimal, with urgent surgery for patients with a neurosensory deficit and intraarterial thrombolytic therapy reserved as an alternative in selected cases with stable ischemia.

Acute Disease↗