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Biomedical subjects

D Bergqvist

Publications and source records attributed to D Bergqvist.

At least 91 records · Page 5Linked to original sources
PubMed2000

A new method of intrathecal PO2, PCO2, and pH measurements for continuous monitoring of spinal cord ischemia during thoracic aortic clamping in pigs.

BACKGROUND: Impaired spinal cord circulation during thoracic aortic clamping may result in paraplegia. Reliable and fast responding methods for intraoperative monitoring are needed to facilitate the evaluation of protective measures and efficiency of revascularization. METHODS: In 11 pigs, a multiparameter PO2, PCO2, and pH sensor (Paratrend 7, Biomedical Sensors Ltd, United Kingdom) was introduced into the intrathecal space for continuous monitoring of cerebrospinal fluid (CSF) oxygenation during thoracic aortic cross-clamping (AXC) distal to the left subclavian artery. A laser-Doppler probe was inserted into the epidural space for simultaneous measurements of spinal cord flux. Registrations were made before and 30 minutes after clamping and 30 and 60 minutes after declamping. The same measuring points were used for systemic hemodynamic and metabolic data acquisition. RESULTS: The mean CSF PO2 readings of 41 mm Hg (5.5 kPa) at baseline decreased within 3 minutes to 5 mm Hg (0.7 kPa) during AXC (P < .01). Spinal cord flux measurement responded immediately in the same way to AXC. Both methods indicated normalization of circulation during declamping. Significant (P < .01) changes were also observed in the CSF metabolic parameters PCO2 and pH. CONCLUSIONS: In this experimental model of spinal ischemia by AXC, online monitoring of intrathecal PO2, PCO2, and pH showed significant changes and correlated well with epidural laser-Doppler flowmetry (P < .01).

Animals↗
PubMed2000

Hemorheologic variables in critical limb ischemia before and after infrainguinal reconstruction.

PURPOSE: Plasma and whole blood viscosity are elevated in patients with intermittent claudication. The objectives of this study were to investigate whether critical limb ischemia influences hemorheologic variables and whether the rheologic variables in blood from the affected limb differ from the general circulation. We also intended to study whether successful infrainguinal reconstruction improved hemorheologic variables. METHODS: Ten consecutive patients with critical limb ischemia (CLI) underwent arterial reconstruction, one patient with profundaplasty and nine patients with bypass procedures. Venous blood was sampled from the antecubital vein (arm) and the femoral vein (leg) of the affected limb 1 day before and 1 month after surgery. Ten control subjects (matched according to age, sex, diabetic status, and renal insufficiency) were also sampled. Whole blood viscosity, plasma viscosity, erythrocyte aggregation tendency, and erythrocyte fluidity (the latter variable describing the deformability of the erythrocytes) were measured by means of rotational viscometry. Erythrocyte volume fraction was also determined. Fibrinogen was measured in the patients with CLI. RESULTS: Erythrocyte fluidity, blood viscosity, and erythrocyte volume fraction were lower in patients with CLI than in control subjects (P <.01, P <.01, and P <.05, respectively). No major differences between cubital and femoral vein blood were seen before or after the operation in patients with CLI or in control subjects. Successful revascularization did not influence the hemorheologic variables, except for a decrease in blood viscosity in femoral vein blood (P <.05). CONCLUSION: Hemorheologic properties was impaired in patients with CLI. Because no differences were seen between the systemic and local circulation and because no major improvement occurred 1 month after arterial reconstruction, other mechanisms besides local tissue ischemia may play a role.

Aged↗
PubMed2000

Cost-effectiveness of prolonged out-of-hospital prophylaxis with low-molecular-weight heparin following total hip replacement.

Several studies have demonstrated that prolongation of thromboprophylaxis after elective hip replacement significantly reduces the frequency of venographically demonstrated deep vein thrombosis. This paper reports an economic evaluation of prolonged prophylaxis with low-molecular-weight heparin (LMWH), based on outcome data from one of these trials. Analysis showed a net saving per patient of 3,400 Swedish kronor. Consequently, if the costs of administering the LMWH -- which includes the cost of teaching the patient to self-administer whilst in hospital and the cost of a follow-up visit by a district nurse to ensure compliance -- are below this amount, the intervention will prove to be cost saving.

Anticoagulants↗
PubMed2000

Intimal hyperplasia recurs after removal of PDGF-AB and -BB inhibition in the rat carotid artery injury model.

Several antagonists specific for platelet-derived growth factor (PDGF) or its receptors have recently been developed and shown to inhibit intimal hyperplasia formation in various animal models, but data investigating the durability of this intervention is limited. The present study was designed to investigate the potency of PDGF B-chain aptamer, a novel type of PDGF-AB and -BB antagonist, in the rat carotid model and to characterize intermediate-term effects on lesion formation. One hundred thirty-four animals were randomized to aptamer treatment or placebo. Daily treatment with the antagonist resulted in a 50% reduction in lesion size at 2 weeks (P<0.001). The beneficial effect involved increased apoptosis and possibly an interference with smooth muscle cell migration. Discontinuing administration 1 week earlier did not give any significant benefit compared with phosphate-buffered saline-treated controls. When the antagonist was administered for 2 weeks and the vessels analyzed 6 weeks later, the beneficial effect was lost and the treated lesions had a higher intima-media and area-cell ratio compared with the treated lesions in the 2-week-endpoint study. Our findings confirm a role of PDGF B-chain in intimal hyperplasia, but the successful use of PDGF antagonists may require either prolonged treatment or combination therapy with other agents.

Angioplasty, Balloon↗
PubMed2000

Incidence of pulmonary embolism: is it declining?

Several factors make analysis of time trends in the incidence of pulmonary embolism difficult. Apart from the methodologic problems, a number of factors could explain an increasing as well as a decreasing incidence. The few studies on pulmonary embolism discovered after death are discussed, and the evidence shows a decrease in incidence, especially after the mid 1970s. This can be explained by many factors, of which the 2 most important are the increased use of thromboprophylaxis and better treatment of established deep vein thrombosis.

Adult↗
PubMed1999

Coagulation and fibrinolysis after open infrarenal abdominal aortic aneurysm repair in a long-term perspective.

In patients with abdominal aortic aneurysms (AAA) the coagulation and fibrinolytic systems have been found to be activated preoperatively. Does the increased activity of the coagulation and fibrinolytic systems persist after AAA surgery in a long-term perspective? Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), tissue plasminogen activator (tPA), human plasminogen activator inhibitor type 1, and human cross-linked fibrin degradation product (D-dimer) were analysed in 18 patients after open AAA surgery (postop-AAA). The median time between surgery and blood sampling was 19 months (range, 5-37 months). Comparisons were made with both preoperative values of 23 patients with AAA (preop-AAA) as well as 20 age-matched healthy controls (AMC). F1+2, TAT, and D-dimer in preop-AAA were significantly higher compared to AMC (p<0.001). In post-op AAA patients these parameters were significantly lower compared to preop-AAA (p<0.05 for F1+2 and TAT, p<0.001 for D-dimer). However, TAT and D-dimer levels were still higher in postop-AAA than in AMC (p<0.01 for both). The activity of the coagulation and fibrinolytic systems seems to decrease after AAA surgery. However, the activity is still higher than in healthy AMC. A possible explanation may be that the thrombogenicity is lower in a vascular graft than in an aneurysmal sac but still higher than in a nonaneurysmal aorta.

Aged↗
PubMed1999

[Intestinal ischemia after abdominal aorta surgery. A dreaded complication surveyed by a combination of different methods].

The article consists of a review of findings in previously published reports on intestinal ischaemia after abdominal aortic surgery. In a combined cohort and case-control study of 2,824 patients from the Swedish vascular registry, the incidence of intestinal ischaemia was 2.8%. The independent risk factors identified were preoperative shock, emergency surgery, renal insufficiency, advanced age, operation at a regional hospital, aortabifemoral grafting, ligation of one or both internal iliac arteries, bleeding > 10 litres, and operating and cross-clamping time. Cardinal symptoms were unreliable predictors. Sigmoidoscopy was potentially diagnostic in 95 per cent of cases. In a clinical study of 34 patients, sigmoid colon pHi was highly predictive of ischaemic colitis and other life-threatening complications. In a por-cine model of ischaemic colitis, blood flow in the superior mesenteric artery, colonic pHi and histological mucosal damage were unaffected by dobutamine.

Aged↗
PubMed1999

[Clinical assessment of critical ischemia is always to be done prior to amputation].

Patients with critical limb ischemia (rest pain and/or ulcer/gangrene, together with low ankle pressure) are at risk of amputation, and should therefore undergo arterial reconstruction if that is at all technically possible. Thorough clinical investigation will usually distinguish patients in need of further evaluation by a vascular surgeon. No amputation should be undertaken without such evaluation. Diabetic patients belong to a special category, in that neuropathy makes it difficult to evaluate pain, and ankle pressure is often falsely high due to medial arterios sclerosis.

Amputation, Surgical↗
PubMed1999

[The diabetic foot. Optimal prevention and treatment can halve the risk of amputation].

Almost half of all lower leg amputations are performed in patients with diabetes. In over 70 per cent of these cases, amputation is precipitated by progression of foot ulceration to deep gangrenous infection. Most foot ulcers are preceded by trauma, usually due to ill-fitting shoes, and are precipitated by sensory motor neuropathy with varying degrees of peripheral vascular disease. The Swedish Medical Research Council and the Swedish Institute for Health Services Development arranged a conference on diabetic foot problems in April 1998, the purpose of which was to arrive at a consensus regarding the prevention and management of diabetic foot. It was concluded that a satisfactory multidisciplinary approach should include regular control of feet and footwear, preventive foot care (education, footwear, chiropody), continuous follow-up of high-risk feet, and early recognition of revascularisation. Continuous registration of amputation, irrespective of type, cause and site, might substantially reduce the amputation rate among diabetics. Were such an approach to reduce the incidence of diabetes-related amputation by 50 per cent, annual costs for the management of diabetic foot in Sweden would be reduce by SEK 400 million (the value of improved quality of life not taken into consideration).

Amputation, Surgical↗
PubMed1999

Intestinal ischemia -- the basics.

INTRODUCTION: In this review the physiology of the intestinal circulation of importance for the understanding of intestinal ischemia is briefly outlined. PERSPECTIVES: The potential threat of massive intestinal vasoconstriction causing nonocclusive intestinal ischemia is discussed, as is the clinical importance of the reperfusion component of the ischemic injury. The clinical causes of intestinal ischemia are outlined. The delay in the usual clinical diagnostic process and its severe consequences are emphasized. Emphasis is made to discuss the special situation with sigmoid gangrene following surgery for ruptured aortic aneurysm. Laparotomy upon clinical suspicion of intestinal ischemia is generally recommended. The various therapeutic surgical measures available if diagnosis is made before massive intestinal gangrene are discussed.

Aortic Aneurysm↗
PubMed1999

Relationship of femorodistal bypass patency to clinical outcome. Iloprost Bypass International Study Group.

OBJECTIVE: To investigate the relationship between bypass patency, limb survival and clinical symptoms after femorodistal bypass procedures. DESIGN: Multicentre, prospectively planned 12-month postoperative follow-up. PATIENTS AND METHODS: Five hundred and seventeen patients undergoing femorodistal bypass surgery for severe ischaemia. Clinical symptoms, bypass patency were recorded at regular intervals up to 12 months postoperatively. RESULTS: Complete follow-up data was obtained on 498 patients (96%). Fifty-six (17%) of the 341 patients with patent bypasses had either rest pain or ulcers or had undergone major amputation at 12 months. Of the 167 patients with an occluded bypass, 22 patients (13%) had improved clinical symptoms and a total of 59 patients (35%) had avoided major amputation at 12 months. The clinical outcome for patients classified preoperatively as Fontaine stage IV was significantly worse than for those in stage III preoperatively despite similar bypass patency rates. CONCLUSIONS: There is a fair correlation between technical and clinical outcome after femorodistal bypass surgery at 12 months, but there are significant numbers of patients with occluded bypasses who have a good clinical outcome and of patients with patent bypasses who have a poor clinical outcome. The reporting of symptoms in addition to bypass patency would aid the interpretation of surgical results.

Adult↗
PubMed1999

Cytokine and fibrinogen response in patients undergoing open abdominal aortic aneurysm surgery.

OBJECTIVES: To assess whether open abdominal aortic aneurysm (AAA) surgery influences cytokines and fibrinogen. METHODS: Twenty-three consecutive patients operated on for AAA were compared to 11 operated controls and 20 age-matched controls. Cubital blood was sampled pre-, intra- and postoperatively and femoral blood also sampled intraoperatively. RESULTS: Preoperatively, interleukin (Il)-6 was elevated in AAA patients. During aortic clamping, Il-6, Il-10 and monocyte chemoattractant protein-1 (MCP-1) increased significantly (p < 0.001, p < 0.01 and p < 0.05 respectively) while soluble interleukin-2 receptor (sIl-2R) and fibrinogen decreased significantly (p < 0.001 for both). After aortic declamping, Il-6, Il-10 and MCP-1 had further significant increases compared with levels during aortic clamping while sIl-2R had a further non-significant and fibrinogen a significant decrease (p < 0.05 in cubital and p < 0.001 in femoral blood). One week postoperatively Il-6, Il-10 and MCP-1 had all decreased but were still significantly elevated compared with baseline values while sIl-2R and fibrinogen showed an increase in comparison with baseline (p < 0.001 for both). Intraoperative levels of Il-6 and Il-10 showed a significant co-variation with the magnitude of operative trauma. CONCLUSIONS: These data indicate that open AAA surgery induces a profound inflammatory and coagulative response which persists at one week postoperatively.

Aged↗
PubMed1999

Ischaemia and reperfusion during open abdominal aortic aneurysm surgery induce extensive thrombin generation and activity.

OBJECTIVES: does open surgery for abdominal aortic aneurysm (AAA) influence coagulation? METHODS: in 23 patients operated on for AAA, cubital blood was sampled pre-, intra- and postoperatively. Femoral blood was also sampled intraoperatively. RESULTS: preoperatively, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and soluble fibrin (SF) were elevated in AAA patients. During aortic clamping all parameters increased significantly in cubital blood (p<0.01) as well as in femoral blood (p<0.001) and after aortic declamping F1+2 and TAT increased further. F1+2, TAT and SF were significantly higher in femoral than cubital blood. Postoperatively F1+2 and TAT returned to preoperative values, while SF still had a significantly higher level than preoperatively (p<0.001). Blood loss showed co-variation with F1+2 increase in femoral blood after aortic declamping (p<0.05). CONCLUSIONS: these data indicate that the coagulation system was strongly activated by the occurrence of an AAA. During AAA surgery a further extensive activation was seen. The activity was still high, but on decline, one week postoperatively. Ischaemia and reperfusion of the lower part of the body were the major stimuli for thrombin generation and activity.

Adult↗