Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the study was to test the hypothesis that significant delays in cutaneous wound healing could be demonstrated using standard wounds and high quality histological methods in patients with severe peripheral vascular disease (PVD) and/or diabetes mellitus (DM) compared to healthy elderly controls. Additionally, we proposed that standard wounds on the arms of elderly controls would heal more rapidly than comparable wounds on the legs. In order to test these hypotheses we developed and characterized a partial thickness wound model which could be used safely in human subjects. The study population consisted of 25 elderly normal volunteers, 17 patients with PVD, and 24 patients with DM. Standard wounds were created using a Simplate II bleeding-time device. A total of 309 wounds ranging in age from 1 to 25 days were determined to be suitable for analysis. A global index of wound maturity was developed based on selected epidermal and dermal events of repair which could be scored histologically. The superficial component (within 0.1 mm of the epidermis) and deep components of dermal wounds were analyzed separately. Simultaneously created arm and leg wounds were studied in 15 of the elderly controls. Transcutaneous partial pressure of oxygen (TcPO2) measurements were used to estimate the severity of cutaneous ischemia. Data analysis revealed that the most striking differences observed were in dermal events of repair. Control wounds were more mature than dermal wounds from patients with PVD (P < 0.05). A significant reduction in the number of neutrophils and macrophages (P < 0.05) was demonstrated in 7-day-old wounds of patients with PVD compared to controls. Patients with DM showed a similar trend of reduced wound maturity but it did not reach statistical significance. Wounds created in skin with TcPO2 > 20 were more mature than wounds with TcPO2 < or = 20 (P < 0.05) and arm wounds were more mature than leg wounds (P < 0.01). The most significant difference noted in this wound model was that the superficial compartment of dermal wounds was significantly more mature than the deep compartment (P < 0.001). Good agreement was observed between two independent scorers of wound histology and no complications were noted in either patients or controls when using this human wound model. We conclude that the model described allows evaluation of both epidermal and dermal events of repair with relative safety even in patients with PVD and DM.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:A model for the study of wounds in normal elderly adults and patients with peripheral vascular disease or diabetes mellitus. 764 93

Determination of the level of amputation of an ischemic lower limb presents a difficult problem. This prospective study evaluated parameter capable of predicting wound healing in patients with peripheral vascular disease. Forty-four amputations performed on 38 patients for advanced ischemia of a lower extremity were analyzed. Among them, 20 patients had diabetes mellitus and 10 received vascular reconstruction prior to the amputation. All patients except one had a skin temperature measurement and 26 patients had segmental blood pressure measurements before amputation. Of the 44 amputations, 31 healed successfully and 13 failed to heal without further intervention. Patients who had an amputation above the ankle joint had a significantly better outcome than those who had amputation below the ankle joint. Among the amputations proximal to the ankle joint, all patients with segmental blood pressures > 70 mmHg at the amputation level had successful wound healing, compared with only half of those patients with segmental pressures < 70 mmHg. However, ankle segmental pressure was not associated with the outcome of wound healing in the amputations distal to the ankle joint. The absolute skin temperature and the difference between the skin and ambient temperature were found to be poor predictors for wound healing. No significant differences were detected among the successes and failures with regard to the patient's sex, age, blood chemistry and duration of diabetes mellitus.
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PMID:Predictors for wound healing in ischemic lower limb amputation. 774 37

During the past 3 years six episodes of ischemic monomelic neuropathy (IMN) have been identified in five patients as a complication of upper extremity dialysis grafts. All patients had long-standing insulin-dependent diabetes, peripheral neuropathy, and brachial artery graft origins, whereas 60% had peripheral vascular disease. Five episodes occurred immediately after graft placement, whereas one was due to a graft-related thromboembolus. Diagnostic delay was common with initial findings attributed to anesthesia, positioning, or surgical trauma. Electrophysiologic studies showed underlying diabetic neuropathy with severe multifocal neuropathy distal to the grafts. Digital pressure indices were reduced but there was no critical ischemia. In three cases ischemia was completely corrected with improvement in one. One patient had proximal balloon angioplasty with no improvement and of the two untreated patients, one improved slightly. Ischemic monomelic neuropathy is a rare but disabling complication of dialysis access in diabetic uremic patients. Its occurrence is unpredictable and diagnostic delay is common. Correction of ischemia is indicated but usually does not improve the neuropathy. Prevention requires further research to more accurately characterize the patients at risk.
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PMID:Ischemic monomelic neuropathy: an under-recognized complication of hemodialysis access. 786 97

Lower-extremity ischemia can lead to impaired healing of saphenous vein excision sites in patients with significant peripheral vascular disease (PVD). Five patients who required infrainguinal revascularization for wound necrosis of the harvest site after coronary artery bypass grafting are described. The male/female ratio was 2:3 with a mean age of 67 (range 45-87) years. The most commonly associated problems were insulin-dependent diabetes mellitus (80%) and congestive heart failure (60%). The saphenous vein was harvested from the thigh and leg in three patients and exclusively from the leg in the others. Manifestations of ischemia ranged from persistent ulceration to complete wound disruption threatening limb loss. Impaired healing was isolated to infragenicular wounds in all patients. Pedal pulses were not detected in any of the affected extremities. Determination of the ankle/brachial pressure indices (ABI) revealed values of < 0.5 in three affected limbs. Non-compressible vessels resulted in falsely raised ABI of > 1.0 in the remaining two limbs; however, Doppler waveform analysis in these patients demonstrated significant PVD. Aggressive wound care and antibiotic therapy were continued for mean of 9 weeks before operative intervention. Infrainguinal reconstruction included femoropopliteal (two), femorotibial (two) and popliteal-tibial bypass (one). Autologous arm and saphenous veins in addition to expanded polytetrafluoroethylene grafts were used effectively. Limb salvage and wound healing were achieved in 100% of the patients without untoward sequelae. It is concluded that unrecognized PVD in patients undergoing coronary artery bypass grafting can lead to significant morbidity. Patients at risk may be identified with a combination of history, physical examination and non-invasive testing.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Vein harvest ischemia: a peripheral vascular complication of coronary artery bypass grafting. 795 53

The role of routine selective angiography of the internal mammary artery prior to myocardial revascularization is controversial. We report a patient with coronary artery disease and peripheral vascular disease in whom the left internal mammary artery supplied blood flow to the left external iliac artery via a collateral network. Thus, selective angiography of the internal mammary artery did play a major role in the proper management of this patient who required coronary bypass surgery. A major potential postoperative complication of left lower extremity ischemia may have been prevented.
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PMID:Internal mammary artery collateral to the external iliac artery: an angiographic consideration prior to coronary bypass surgery. 798 15

Resistance to O2 diffusion is reflected in the difference in pO2 between O2 reservoirs of hemoglobin (Hb) and myoglobin. The very low normal myocyte pO2 (less than one torr but adequate for optimal oxidative ATP synthesis) compared to venous pO2 indicates that blood does not achieve equilibrium with tissue during its passage through capillaries. In the lung, diffusion rate of O2 from alveolus to capillary is normally sufficient to achieve essential equilibrium. However, system-wide capillary pathology and reduced Hb saturation has been observed with distal local ischemia. In peripheral vascular disease (PVD) patients, we found a mean arterial pO2 of 77 torr (normal over 90 torr). Classical concepts based on "tissue pO2" values derived from venous blood or oxygen electrodes inserted into tissue need re-evaluation. Readings of O2 electrodes moved through tissue range widely from intracapillary levels down toward intracellular levels and do not reflect the pO2 of any particular site. Intravenous pO2 is the result of residual O2 after incomplete diffusion out of capillaries during transit through a tissue, and is not an equilibrium value with some tissue pool. The effect of HbO2 p50 on oxygen release during the passage of blood through a capillary bed, generally judged on the basis of percentage percent saturation at "tissue pO2", should be judged on the basis of the change in pO2 (the diffusion driving force) associated with a particular degree of HbO2 saturation at a particular p50. The thesis that O2 diffusion rate is a major determinant of oxygen delivery is supported by pO2 responses to treatment of PVD that does not alter blood flow or p50.
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PMID:Concepts of "tissue PO2" in relation to O2 delivery. 799 99

Revascularization after prolonged complete limb ischemia may result in severe damage to skeletal muscle and systemic alterations (postischemic syndrome). Our previous experimental studies have shown that this injury can be reduced substantially by treating the jeopardized extremity by controlling the conditions of reperfusion and composition of the initial reperfusate. In the present study this concept of controlled limb reperfusion was applied in patients with prolonged severe limb ischemia. Controlled limb reperfusion was used in 14 patients after prolonged complete uni- or bilateral ischemia. The ischemic interval ranged from 5 to 21 h. Two patients were in cardiogenic shock, 11 had associated cardiac disease, and seven coexistent peripheral vascular disease. After systemic heparinization, standard thromboembolectomy was done using a Fogarty catheter. Cannulas were placed into the iliac, profunda, and superficial femoral arteries and were connected to a reperfusion set. Oxygenated blood was drawn from the iliac artery and mixed with an asanguineous solution (ratio 6:1). This controlled reperfusate was delivered into the profunda and superficial femoral arteries using a single rollerpump. The system allows control of the composition of the reperfusate (calcium, pH, osmolarity, glucose, substrate, pO2, free radical scavengers) and the conditions of reperfusion (pressure, flow, temperature). After 30 min of controlled limb reperfusion, the cannulas were removed and normal blood reperfusion started. All 12 patients who were stable hemodynamically before the operation survived the revascularization. Eleven patients, including one with acute aortic occlusion for several hours, were discharged with functional recovery of their extremities. Despite the severe ischemic insult, controlled limb reperfusion avoided amputation and profound systemic complications. Two patients who were in cardiogenic shock preoperatively died from progressive cardiac failure. We conclude that controlled arterioarterial limb reperfusion may reduce the local manifestations of the postischemic syndrome after prolonged periods of ischemia, may salvage limbs thought previously to be damaged irreversibly by prolonged ischemia, and can be done easily in the operating room.
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PMID:New surgical treatment for severe limb ischemia. 800 66

Intra-arterial thrombolytic therapy is an important advance in the treatment of arterial occlusive disease. Reports of results, morbidity, and mortality have been highly variable. This review was undertaken to assess the recent results of thrombolytic therapy with urokinase (UK) at our institution. From 1988-1992, 42 lower extremities in 41 patients with severe peripheral vascular disease underwent intra-arterial thrombolytic therapy. Sites of occlusion consisted of 6 iliac, 21 superficial femoral, 11 popliteal, and 20 infra-popliteal segments. Lytic therapy consisted of a regional infusion of UK with concomitant heparin anticoagulation. The most common UK loading dose was 250,000 units (60,000-750,000) followed by a continuous infusion of approximately 100,000 units/hour (60,000-240,000) for up to 72 hours. Technical success, defined as partial or total resolution of the arterial occlusions, occurred in 26 (62%) limbs. A concomitant endovascular procedure was required in 19 extremities following successful lysis. Immediate clinical success, defined as restitution of a distal pulse or increase in ABI > 0.10, occurred in 22 of 26 technically successful procedures. The four clinical failures and all 16 technical failures required either a major amputation or revascularization. There were 18 major complications in 18 patients (43%): seven thromboembolic, two arterial dissections, nine hemorrhagic. Seven hemorrhagic complications required transfusion of 1-6 units of blood, and two deaths occurred due to postprocedural hemorrhage, shock, and myocardial infarction. Hemorrhage was not related either to the dose of UK or the duration of UK infusion. A combination of thrombolysis and endovascular intervention can be of significant benefit in selected patients with extremity ischemia. However, complications are frequent and may be lethal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thrombolytic therapy for arterial occlusion: a mixed blessing. 816 Oct 90

Sciatic nerve lesions occur only rarely in cardiac surgery patients. To evaluate potential causes for sciatic neuropathy, we reviewed the cardiac surgery performed at one institution during the last 15 years and found only six instances of sciatic neuropathy. We examined medical records for these six patients for potential etiologic factors and determined that four of the six patients had undergone prolonged periods of intra-aortic balloon pump therapy with a catheter placed through the femoral artery ipsilateral to the sciatic nerve lesion, and the other two patients had an ipsilateral femoral artery occlusion. In addition, four of the six patients had severe symptomatic peripheral vascular disease, and one of the other patients had severe and prolonged perioperative hypoxia. Although all these patients had pure sciatic neuropathy clinically, two of the four patients studied with electromyography had evidence of damage to the femoral nerve or quadriceps muscles ipsilaterally. In addition to the neurogenic changes, there were electromyographic findings suggestive of muscle ischemia. These results indicate that patients undergoing cardiac surgery may be at risk for development of a sciatic neuropathy if they have compromised blood flow through the femoral artery together with another cause for tissue hypoxia. Furthermore, asymptomatic ischemia of the femoral nerve or quadriceps muscles may occur in this clinical setting.
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PMID:Sciatic nerve lesions during cardiac surgery. 816 26

A higher prevalence of stroke is found in the patient with both diagnosed and undiagnosed diabetes and glucose intolerance. Because of local cerebral acidosis caused by ischemia and hyperglycemia, morbidity and mortality from a stroke are increased. Most studies show that individuals with admission serum glucose > 120 mg/dl (6.7 mM) have a higher morbidity and mortality from a stroke. The prevalence of cerebral infarcts, especially lacunar infarcts, is increased and the prevalence of subarachnoid hemorrhage, cerebral hemorrhage, and transient ischemic attacks are decreased in the diabetic patient. Age, race, hypertension, and the presence of diabetic nephropathy and coronary and peripheral vascular disease are risk factors for stroke in the diabetic patient, whereas obesity, smoking, hyperlipidemia, and glycemic control are not. Investigation and treatment of the diabetic patient with a stroke is discussed.
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PMID:Stroke in the diabetic patient. 817 50


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