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Biomedical subjects

R D Levy

Publications and source records attributed to R D Levy.

At least 55 records · Page 3Linked to original sources
PubMed1996

Penetrating injuries of the abdominal inferior vena cava.

This is a retrospective study of 74 patients with penetrating injuries of the abdominal inferior vena cava; the cause of injury was gunshot in 91% and stabbing in 9%. Of the patients, 77% underwent lateral venorrhaphy, 5% underwent infrarenal ligation of the inferior vena cava (IVC), and 18% died perioperatively before any caval repair could be carried out. There was an overall perioperative mortality of 39%. Persistent shock, the site of the venous injury, particularly in the retrohepatic position, and the number of associated vascular injuries were directly related to mortality. Irrespective of the improvements in resuscitation and the various operative methods available, penetrating trauma of the abdominal IVC remains a life-threatening injury.

Abdominal Injuries↗
PubMed1995

Short-term pulmonary vasodilation with L-arginine in pulmonary hypertension.

BACKGROUND: Endothelial dysfunction may contribute to the pathogenesis of pulmonary hypertension through impaired production of the endothelium-derived vasodilator nitric oxide (NO). L-Arginine, the substrate for NO synthase (NOS), has a vasodilatory effect in systemic vascular beds and can correct abnormal endothelium-dependent vasodilation. It has been suggested that these two effects of L-arginine are mediated through NOS metabolism and enhanced NO production. Therefore, we assessed the short-term pulmonary hemodynamic effects of exogenous L-arginine in patients with pulmonary hypertension of various origins. METHODS AND RESULTS: During continuous hemodynamic monitoring, 10 subjects with pulmonary hypertension (mean pulmonary artery pressure [PAP], 54 +/- 5 mm Hg [mean +/- SEM]) received a 30-minute control infusion of hypertonic saline followed by a 30-minute infusion of 500 mg/kg of L-arginine. The hemodynamic effects of L-arginine were compared with those of prostacyclin titrated to maximally tolerated doses. The hemodynamic response to L-arginine was also studied in 5 subjects with heart failure but without pulmonary hypertension (mean PAP, 20 +/- 2 mm Hg) and 5 healthy control subjects. In subjects with pulmonary hypertension, infusion of L-arginine reduced mean PAP by 15.8 +/- 3.6% (P < .005) and pulmonary vascular resistance (PVR) by 27.6 +/- 5.8% (P < .005) compared with decreases of 13.0 +/- 5.5% (P < .005) and 46.6 +/- 6.2% (P < .005), respectively, with prostacyclin. L-Arginine infusion also increased the mean plasma level of L-arginine from 59 +/- 6 mumol/L to 10,726 +/- 868 mumol/L (P < .005), which was associated with a significant increase in the plasma level of L-citrulline, the immediate product of NOS metabolism of L-arginine. Moreover, the peak plasma level of L-citrulline correlated significantly with the reductions in mean PAP (r = .71, P < .05) and PVR (r = .70, P < .05), consistent with vasodilation mediated by NOS metabolism of exogenous L-arginine and increased NO production. L-Arginine also had a modest hypotensive effect in healthy control subjects and reduced systemic vascular resistance in subjects with heart failure in the absence of pulmonary hypertension. However, only small reductions in absolute pulmonary vascular resistance were observed in this latter group in response to L-arginine that did not reach significance. CONCLUSIONS: An exaggerated short-term pulmonary vasodilatory response to L-arginine in patients with pulmonary hypertension suggests a relative impairment in pulmonary vascular endothelial NO production that may contribute to increased pulmonary vascular tone and thus be important in the pathophysiology of pulmonary hypertension.

Adult↗
PubMed1995

Acute effects of glyburide on the regulation of peripheral blood flow in normal humans.

Recent animal studies have demonstrated that selective blockade of ATP-sensitive K+ (KATP) channels of vascular smooth muscle results in a significant increase in peripheral vascular tone. The main aim of this study was to assess whether glyburide, a selective blocker of KATP channels and commonly used antidiabetic agent, influences resting blood flow and reactive hyperemic response of peripheral tissues of normal subjects. Baseline calf blood flow was measured non-invasively in six normal subjects with femoral venous occlusive plethysmography. Calf blood flow was also serially measured every 30-60 s after the release of calf arterial occlusion (10 min duration). Reactive hyperemia was expressed in terms of peak post-occlusive flow, duration of hyperemia and reactive hyperemic volume. In each subject, baseline flow and reactive hyperemia were measured before (control) and every hour for 5 h after the oral ingestion of either 7.5 mg glyburide or a placebo on two separate days. Baseline calf flow declined by 30 and 42% of control values after 1 and 2 h of glyburide intake (P < 0.05) with a return to control values by hours 3, 4 and 5. Peak post-occlusive flow after 1, 2 and 3 h of glyburide ingestion was lower than control values by 22, 30 and 28%, respectively (P < 0.05). The duration of reactive hyperemia after 2 and 3 h of glyburide ingestion was significantly longer than control values (P < 0.05), whereas reactive hyperemic volume remained unaffected by glyburide intake. Placebo elicited no significant changes in baseline flow or reactive hyperemia throughout the 5-h experimental period.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

Penetrating injuries of the femoral artery.

This is a retrospective study of 106 patients with penetrating injuries to the femoral artery. The cause of injury was gunshot in 82 per cent, stabbing in 13 per cent and pellets in 5 per cent. We believe that angiography is unnecessary in patients with 'hard' signs of vascular injury: 97 patients underwent immediate exploration with positive findings. The presence of 'soft' signs alone mandates angiography as five of 12 patients with suspected injury were saved a negative exploration. Proximity of injury was a poor predictor of arterial injury. There were four amputations. Ligation of the femoral vein is not reliably associated with amputation but it was an aggravating factor in the setting of severe arterial disruption and delay to surgery.

Adolescent↗
PubMed1995

Distal pancreatectomy for gunshot injuries of the distal pancreas.

This study comprised 57 patients with gunshot injury of the distal pancreas. There were 16 grade II, 29 grade III and 12 grade IV pancreatic injuries. The intraoperative mortality rate was 12 per cent. Patients with the most severe grade II injuries and all those with grade III and IV injuries had distal pancreatectomy and splenectomy, with a 14 per cent fistula formation rate and 2.3 per cent postoperative mortality rate directly related to the pancreatic injury. The remaining patients with grade II injuries were managed by debridement and drainage; there were no fistulas or deaths. The method of closure of the pancreatic resection margin is unrelated to fistula formation, and identification of the duct for ligation is unnecessary. Liberal use of distal pancreatectomy with splenectomy for gunshot injuries of the distal pancreas is suggested.

Adult↗
PubMed1995

Penetrating injuries of the brachial artery.

This is a retrospective study of 72 patients with non-iatrogenic penetrating injuries of the brachial artery treated between 1991 and 1993. The mechanism of injury was stabbing in 39 per cent, a bullet in 51 per cent, pellets in 4 per cent and a dog bite in 6 per cent. We believe that angiography is rarely indicated, as in all our patients the diagnosis was made on clinical grounds. The proximity of the injury to neurovascular bundles was a poor predictor of arterial injury. One month after discharge 95 per cent of the patients had palpable distal pulses. Long-term morbidity is mainly attributed to associated nerve injuries.

Adolescent↗
PubMed1995

Gunshot injuries of the liver: the Baragwanath experience.

BACKGROUND: This study comprised 304 patients with gunshot injuries of the liver, many of which from high-velocity firearms. The purpose of this study is to evaluate our management policy in gunshot injuries of the liver in light of our recent wider experience. METHODS: All grade I and II injuries and most grade III injuries were managed by simple operative measures, without postoperative mortality directly related to the liver trauma. RESULTS: Grade III, IV, and V injuries had 8.5%, 52%, and 16% resectional debridement rates and 8.5%, 38%, and 84% perihepatic packing rates, respectively. In the resectional debridement group the postoperative mortality rate was 15% (half the deaths were directly caused by the hepatic injury). The postoperative mortality rate in the perihepatic packing group was 31.5% of which 45% of deaths were due to ongoing bleeding, 27.5% to sepsis, and 27.5% to associated trauma. The septic complications were less common when packs were removed early. CONCLUSIONS: We suggest that resectional debridement and perihepatic packing should be liberally applied in the most severe grade III, most grade IV, and grade V gunshot injuries of the liver and that perihepatic packing should be removed as early as the physiologic derangements are corrected. Our experience with grade VI injuries is very limited, and their management should be studied in larger series.

Adolescent↗
PubMed1995

Extraperitoneal rectal gunshot injuries.

Extraperitoneal rectal gunshot injuries are rare, but may be encountered in civilian practice. We report on a series of 26 such cases. The aim of the study is to attempt to evolve a treatment policy of this injury. The principles of management include the repair of rectal wound in selected cases and the formation of a diverting colostomy. Distal rectal washout and presacral drainage, although advocated by some authors, do not seem to be indispensable adjuncts to the management of these injuries.

Adolescent↗
PubMed1995

Arterial gunshot injuries of the extremities: a South African experience.

This is a retrospective study of 173 patients with gunshot injuries of the major arteries of the extremities. A selective policy for the use of angiography was followed. The arterial repair was achieved by various means: primary end-to-end anastomosis, vein interposition graft, and polytetrafluoroethylene (Teflon) interposition grafts. Overall, there were nine amputations in the lower limb. Ninety-eight percent of the patients had a palpable pulse on discharge. There were 3 preoperative deaths, 1 intraoperative death, and 5 postoperative deaths (overall perioperative mortality, 3.5%). We conclude that the results of vascular extremity gunshot injuries are satisfactory when standard methods of management are used. Morbidity and mortality can be further reduced by prompt admission to appropriate centers.

Adolescent↗
PubMed1995

Penetrating injuries of the axillary artery.

This is a retrospective study of 32 patients with penetrating injury of the axillary artery. There was an overall mortality of 6% entirely accounted for by associated injuries. Pre-operative angiography was used in 12 of these patients either to confirm the presence of an injury or to define its location. Twelve patients underwent lateral arteriorrhaphy or an end-to-end anastomosis and 19 patients had an interposition graft. No immediate problems were experienced with polytetrafluoroethylene grafts compared with autogenous vein grafts. There were 14 patients with a concomitant venous injury; 13 were repaired and only transient arm oedema was experienced. Eleven patients had a brachial plexus injury and, of these, nine underwent a secondary nerve repair with a poor outcome. Axillary artery injury has a good prognosis with a morbidity related mainly to associated nerve injury and a mortality accounted for by injuries to other body systems.

Adolescent↗
PubMed1995

Constrictive bronchiolitis obliterans following gold therapy for psoriatic arthritis.

A 41 year old male with psoriatic arthritis developed progressive dyspnoea and airflow obstruction following 4 months of intramuscular gold therapy. Open lung biopsy revealed bronchiolitis obliterans of the constrictive type. This case suggests a possible aetiological role for gold in the pathogenesis of constrictive bronchiolitis obliterans, or alternatively an association between psoriatic arthritis and this inflammatory airway condition.

Adult↗
PubMed1995

Leiomyosarcoma of the breast. A case report.

A case of primary leiomyosarcoma of the breast in a 35-year-old woman is presented. The condition is rare, only 11 cases of primary leiomyosarcoma of the breast having been reported previously. The clinical and pathological features are reviewed.

Adult↗
PubMed1994

Penetrating injuries of the subclavian vessels.

A study was made of 76 patients with subclavian vessel injury. The mechanism of trauma was stabbing in 40 patients (53 per cent) and gunshot in 36 (47 per cent). There were marked differences between the two groups in clinical presentation, operative management and outcome. The group with gunshot injury was characterized by a more immediate threat to life, and a greater need for a median sternotomy and use of interposition grafts. The mortality rate in patients with gunshot wounds was more than twice that in the group with stab injury.

Adult↗
PubMed1994

Penetrating cardiac injuries: clinical classification and management strategy.

The management of penetrating cardiac injury is controversial. To facilitate decision making, a simple clinical classification of patients with such an injury is proposed. Five categories are considered: (1) lifeless, (2) critically unstable, (3) cardiac tamponade, (4) thoracoabdominal injury and (5) benign presentation. Investigation, if indicated, and the timing and setting of surgical intervention are discussed for each category.

Emergencies↗
PubMed1994

Aortic valve replacement for end-stage aortic valve disease.

To evaluate the outcome of surgical intervention for end-stage aortic valve disease, we carried out a retrospective, longitudinal survey of 85 patients (65 males, 20 females; mean age 53 period. All the patients presented in New York Heart Association (NYHA) class IV in cardiac failure (3 had cardiogenic shock and 27 had bacterial endocarditis). In-hospital mortality was 9.4% (8/85) overall. Those with endocarditis had a significantly higher mortality, 6/27 (22%) vs 2/58 (3.4%), p < 0.01. In-hospital mortality was not significantly increased in those with renal failure, reoperation, simultaneous coronary artery surgery, age > 65 years nor was it related to the predominance of aortic regurgitation or stenosis. After a mean follow-up period of 5.9 years (range 0 to 12.5 years), the overall actuarial survival was 82% and 74% at 5 and 10 years respectively. For 66 late survivors, the NYHA status improved to class I in 51, to II in 10, to III in 4 patients, and one patient remained in class IV. The incidence of paraprosthetic leak, reoperation, thromboembolism, anticoagulant-related haemorrhage, and endocarditis were respectively 0.8, 0.8, 1.6, 1.4, and 0.2 per 100 patient-years. Aortic valve replacement in the patient with end-stage aortic valve disease is a high-risk procedure, the risk being higher in the presence of endocarditis. The favourable long-term survival, long-term improvement in functional class and the relatively low incidence of valve-related complications justify surgical intervention in such patients, who would otherwise have a very poor prognosis.

Adolescent↗
PubMed1994

Do specific HLA antigens predispose to ischaemic heart disease or idiopathic dilated cardiomyopathy?

BACKGROUND: The aetiology of idiopathic dilated cardiomyopathy is believed to have an immunological component. Association with human leucocyte antigens (HLAs) has been previously reported, particularly with HLA-DR4. AIM: To determine the association of HLA type with diagnosis in a group of patients assessed for heart transplantation. METHODS: A comparison was made of frequencies of HLA types in patients with a diagnosis of idiopathic dilated cardiomyopathy or (n = 98) ischaemic heart disease (n = 170) and in controls from the North Western region (n = 857). RESULTS: Neither the patients with idiopathic dilated cardiomyopathy nor those with ischaemic heart disease showed a significant increase or decrease in any HLA frequency compared with the controls. CONCLUSION: These results suggest that there is no HLA association with idiopathic dilated cardiomyopathy or ischaemic heart disease. This conflicts with the results of some previous studies.

Cardiomyopathy, Dilated↗