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Biomedical subjects

L Jivegård

Publications and source records attributed to L Jivegård.

At least 37 records · Page 2Linked to original sources
PubMed1992

Preoperative assessment of the risk for cardiac death following thrombo-embolectomy for acute lower limb ischaemia.

Cardiac monitoring and the selective use of initial non-operative management is reported to reduce the high mortality rate in patients with acute lower limb ischaemia. Early estimation, prior to selection of initial therapy, of the risk for intraoperative or postoperative cardiac death following thrombo-embolectomy is therefore important. The aim of this prospective multi-centre study was to develop a simple and clinically useful index for assessment of the risk of post-operative cardiac death. Patients judged to need thrombo-embolectomy for acute lower limb ischaemia were evaluated on admission for routine clinical, cardiac and limb ischaemia parameters that could be related to cardiac function and these parameters compared to postoperative cardiac outcome. Sixteen per cent of the 117 patients died from intraoperative or postoperative cardiac complications. Analysis revealed five admission parameters that significantly and independently predicted a high risk for cardiac death: mean arterial blood pressure below 90 mmHg, clinical sign(s) of cardiac decompensation, ischaemia affecting the thigh, haemoglobin concentration exceeding 140 gl-1, and a history of a myocardial infarction in the previous 4 weeks. Definition of risk points for each risk factor allowed a simple classification of each patient into one of three significantly different cardiac risk classes with cardiac death rates of 6 +/- 3%, 27 +/- 8% and 75 +/- 16%, respectively. More than two thirds of the patients belonged to the low risk group. The described risk index provides a tool for preoperative assessment of the cardiac death risk associated with early thrombo-embolectomy in patients with acute lower limb ischaemia.

Aged↗
PubMed1992

Location of enkephalinase and functional effects of [Leu5]enkephalin and inhibition of enkephalinase in the feline main pancreatic and bile duct sphincters.

1. Morphological studies have demonstrated enkephalinergic nerve fibres in proximity to the sphincter of Oddi, and opiates are known to contract this sphincter. In this study, the flow resistances in the common bile duct and main pancreatic duct sphincters were studied simultaneously in anaesthetized cats using a perfusion technique. 2. Naloxone did not affect the activity of these sphincters under basal conditions, indicating that there is no basal enkephalinergic tone. 3. The response to [Leu5]enkephalin (0.015-15 micrograms/kg), morphine (1 mg/kg) and ketamine (10 mg/kg) was a naloxone-sensitive increased activity in the sphincters with a raised frequency of phasic contractions. The threshold dose for an effect of [Leu5]enkephalin on the sphincter of Oddi was 0.015 microgram/kg and a maximal response was observed at 0.75 microgram/kg. There were no differences in the response of the main pancreatic duct sphincter and the bile duct sphincter to the different drugs. 4. Immunoautoradiographic studies demonstrated enkephalinase in the sphincter++ of Oddi. 5. Acetorphan (3 mg/kg intravenously), which inhibits endogenous enkephalinase both in the peripheral and the central nervous system when administered parenterally, caused a naloxone-sensitive contraction, whereas thiorphan (3-20 mg/kg), an enkephalinase inhibitor that does not easily penetrate the blood-brain barrier, had no effect on the sphincter of Oddi. 6. These results show that endogenous and exogenous opiates influence the function of the feline sphincter of Oddi and that enkephalins may be involved in the physiological control of this sphincter, although not under basal conditions.

Animals↗
PubMed1991

Chronic lower limb ischaemia. A prospective randomised controlled study comparing the 1-year results of vascular surgery and percutaneous transluminal angioplasty (PTA).

In a prospective randomised study, performed over a 6-year period, 102 patients with severe lower limb ischaemia or claudication resistant to exercise training were randomised either to percutaneous transluminal angioplasty (PTA) or vascular surgery. Only patients who could be treated by both methods were included, constituting only 5% of the total number of patients treated during this period. The two groups were similar regarding age, severity of symptoms and diabetes. The immediate and 1-year results showed similar success and complication rates. There was, however, a significantly shorter hospital stay for patients treated with PTA. Due to early complications and initial failures PTA should, however, only be used in institutions where vascular surgical facilities are available since PTA demands access to such treatment.

Adult↗
PubMed1991

Abdominal aortic aneurysm with perianeurysmal fibrosis: experience from 11 Swedish vascular centers.

Case records of 2026 patients operated on because of abdominal aortic aneurysms from 11 Swedish Vascular Centers were reviewed and revealed 98 cases (4.8%) of inflammatory abdominal aortic aneurysm. Also included in this case-control study was an analysis of a randomized group of 82 patients from the same centers who had noninflammatory abdominal aortic aneurysms. Four inflammatory aneurysms were ruptured, compared with 16 in the noninflammatory group (p less than 0.01). A higher proportion of patients with inflammatory abdominal aortic aneurysms had symptoms that led to radiographic investigations. The median erythrocyte sedimentation rate was 39 mm versus 19 mm (26% of patients with inflammatory abdominal aortic aneurysms had erythrocyte sedimentation rates greater than 50 mm; p less than 0.001), and the serum creatinine level was increased in 27 and 8 patients (p less than 0.01) in the inflammatory and noninflammatory groups, respectively. Preoperative investigations revealed ureteral obstruction in 19 patients with inflammatory abdominal aortic aneurysms, of whom 12 had preoperative nephrostomy or ureteral catheter placement. At operation, 20 additional patients exhibited fibrosis around one or both ureters. Although ureterolysis was performed in 19 patients, preoperative and postoperative creatinine levels did not differ between these patients and the conservatively treated ones. Duration of surgery (215 vs 218 minutes), intraoperative blood loss (2085 vs 2400 ml) and complications did not differ significantly between the groups. Overall operative (30-day) mortality was equal (11% vs 12%) but was increased for patients undergoing elective surgery for inflammatory abdominal aortic aneurysms (9% vs 0%; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Acute lower limb ischemia: failure of anticoagulant treatment to improve one-month results of arterial thromboembolectomy. A prospective randomized multi-center study.

The value of short-term anticoagulant treatment in improving the early outcome in patients operated on for acute lower-limb ischemia has been debated and so far unproven. In this prospective randomized multi-center study, 188 such patients were randomized on admission, either to preoperative and postoperative anticoagulant medication (AC group, n = 94) or no anticoagulant treatment during the first month after surgery (O group, n = 94). Background factors were evenly distributed in the two groups, and 89% of the cases were considered as embolic. Analysis on an intention-to-treat basis showed no differences in outcome after 30 days. Good results, survivors who had amputation, and patients who died in the two groups are given respectively: AC group, 61%, 9%, 30%; O group, 65%, 11%, 24%. The results were similar in the two treatment groups also if only patients with a cardiac source of embolism were analyzed. Local bleeding complications were more common in the AC group (17% vs 2%, p less than 0.01). It is concluded that preoperative and early postoperative anticoagulant medication should not be routinely administered since such treatment is unlikely to improve the short-term results of lower-limb arterial thromboembolectomy while bleeding complications increase. The possible value of late (beyond 1 month) long-term anticoagulant treatment remains to be studied.

Amputation, Surgical↗
PubMed1990

Acute embolic lower limb ischaemia is associated with decreased red cell deformability.

Red cell deformability is an important determinant of peripheral blood flow. In this study the red cell filtration rate (RFR) was measured in 17 patients admitted for acute embolic lower limb ischaemia. The severity of the limb ischaemia on admission was scored from 0 to 6 depending on the degree of pain, and loss of motor and sensibility functions in the ischaemic extremity. Patients who presented with very severe ischaemia on admission underwent early embolectomy whereas those with less severe ischaemia (range from 0 to approximately 3 in ischaemic score) initially were treated conservatively with heparin. Red cell filtration rate was assessed with a standard microfiltration method and expressed in microliters/sec. On admission the RFR averages 30 +/- 5 microliters/sec (mean +/- S.D.), significantly lower than the corresponding value in a normal population of similar age (50 +/- 5 microliters/sec). There was an inverse relationship (r = 0.74, P less than 0.001 by use of linear regression analysis) between the ischaemic score and the RFR on admission, with low RFR values being related to high ischaemic scores. Forty-eight hours after revascularisation, the RFR had improved significantly in the patients having undergone successful revascularisation, whereas it was unchanged in conservatively treated patients. It is concluded that patients with acute embolic lower limb ischaemia have an impaired red cell filtration rate suggesting decreased red cell deformability, the impairment being related to the severity of the ischaemia. A poor red cell filtration rate on admission is related to increased risk of postoperative gangrene and/or cardiac death. Successful revascularisation, but not conservative heparin treatment is associated with increasing deformability.

Aged↗
PubMed1990

A stable prostacyclin analogue (iloprost) in the treatment of ischaemic ulcers of the lower limb. A Scandinavian-Polish placebo controlled, randomised multicenter study.

The clinical efficacy of the prostacyclin analogue iloprost was studied during a 2 week treatment and 6 month follow-up period in 103 patients with ischaemic ulcers who were randomised to receive active treatment or placebo. Responders were defined as those patients who achieved healing of at least one third of the ulcer area during the study period. The overall responder rate was 41.3%, compared with 25% for the control group (P = 0.086). Side effects including flushing and headache, were common. The study population had a mortality of 23% during the 6 month period, the amputation rate was 43.5% for iloprost and 50% for placebo treated patients. In this severely diseased population of patients a treatment period limited to 2 weeks did not sufficiently improve ulcer healing.

Adult↗
PubMed1990

Cardiac output in patients with acute lower limb ischaemia of presumed embolic origin--a predictor of severity and outcome?

Cardiodynamic studies using a non-invasive computerised thoracic electrical bioimpedance (TEB) equipment were performed in 35 patients presenting with acute lower limb ischaemia of presumed embolic origin, and in 36 age-matched control patients without emboli. Patients who presented with imminent gangrene were promptly operated upon, whereas those who had less severe ischaemia were treated initially with heparin only. In the former group, cardiac output and myocardial contractility were very low on admission, while systemic vascular resistance was high. Cardiac output was further decreased when measured immediately after revascularisation, whereas it had become normal 2 days later. In patients with less severe acute ischaemia, cardiac output and myocardial contractility values on admission were similar to those of control patients, and no changes were observed after 2 days of conservative treatment. Overall, cardiac output on admission was significantly related to the simultaneously observed severity of the limb ischaemia. A low cardiac output (less than 1.7 l/min m2) on admission was found to predict severe cardiac complications (60% mortality within 10 days), whereas clinical assessment of cardiac failure on admission was poorly related to outcome. We conclude that patients with acute lower limb ischaemia of presumed embolic origin often have unrecognised poor cardiac function, which is related to the severity of the limb ischaemia and to outcome. By routine non-invasive TEB cardiodynamic measurements, high risk patients can rapidly be identified and proper treatment regimes be instituted in each individual patient.

Aged↗
PubMed1990

Cardiac output determinations in the pig--thoracic electrical bioimpedance versus thermodilution.

The accuracy of transthoracic electrical bioimpedance (TEB) for continuous, noninvasive measurement of cardiac output (Qt) in pigs was assessed in comparison with the thermodilution (TD) technique. Using the TEB technique, the different thoracic habitus of the pig had to be corrected for A good correlation with the TD technique was obtained (r = .87; p less than .001; n = 86) using thoracic length value (the measured value plus 25%) in an NCCOM3-R6 cardiodynamic computer for Qt values ranging from 2.9 to 9.8 L/min in pigs weighing from 40 to 75 kg. However, the Qt values given by the NCCOM3 were systematically 11% to 15% higher over the full range of values than the average of NCCOM-3 and TD Qt values. On the basis of the good agreement in the present study between the TEB and TD techniques over a broad range of Qt values, we conclude that TEB offers a valuable continuous, noninvasive alternative to TD for Qt determinations in experimental porcine models.

Animals↗
PubMed1990

A porcine model for acute distal aortic occlusion.

Periarterial and intramural nerves and lymphatics as well as the vascular endothelium may influence pathophysiologic responses to acute arterial occlusion. For study of such pathophysiologic patterns, experimental models resembling the clinical situation are therefore preferable. In this porcine study acute distal aortic occlusion was mimicked by use of a balloon catheter introduced via a vascular graft anastomosed to the lateral aortic wall. Peripheral circulatory disturbance was assessed by measurements of femoral vein blood flow, skin blood flow in the hind foot and oxygen tension in the calf muscle, which verified the degree of ischemia. During the 4-hour ischemic period, repeated arterial and venous blood gas analyses showed increasing acidosis in effluent venous blood from the hind limbs, which after reperfusion slowly normalized. As highly reproducible conditions are achievable with the present experimental model, it can be used for studies of pathophysiologic responses to acute distal aortic occlusion.

Animals↗
PubMed1989

Vasoactive intestinal peptide in the normal and inflamed feline gallbladder.

Intravenous infusion of vasoactive intestinal peptide (VIP) causes gallbladder mucosal fluid secretion by an action on epithelial cell receptors in the cat. Gallbladder fluid secretion is observed also in experimental cholecystitis and this secretion is abolished when the intramural gallbladder nerves are blocked. In the present study, immunoreactive VIP was detected in the gallbladder contents (29 +/- 5 (S.E.M.) pM) in the obstructed lumen of the gallbladder in cats with experimental cholecystitis and gallbladder mucosal fluid secretion, but not in the normal feline gallbladder. During luminal perfusion of the gallbladder in vivo, the calculated secretion of VIP into the gallbladder lumen in animals with experimental cholecystitis was significantly higher (0.31 +/- 0.08 (S.E.M.), pmol/h) than in controls (0.11 +/- 0.02 (S.E.M.), pmol/h) while plasma levels of VIP were similar. Recovery of exogenously administered VIP was similar in normal and inflamed gallbladders. The present results support the hypothesis that intramural VIP-releasing nerve fibers may be activated in cholecystitis.

Animals↗
PubMed1989

Naloxone-reversible inhibition of gall-bladder mucosal fluid secretion in experimental cholecystitis in the cat by acetorphan, an enkephalinase inhibitor.

1. Enkephalin immunoreactive nerve fibres have been demonstrated in the gall bladder of various mammals including man. In various tissues, enkephalins are partly degraded by a membrane metallo-endopeptidase, enkephalinase (EC 3.4.24.11). 2. Using 3H-labelled [D-Ala2,Leu5]enkephalin as a substrate, enkephalinase activity, immunoprecipitated by a monoclonal antibody directed against the rabbit kidney enzyme, was demonstrated in the feline gall bladder. Using the same antibody in 125I-labelled form, the peptidase was immunolocalized by autoradiography, mainly in the epithelium. 3. In experimental cholecystitis, elicited by implantation of human gall-stones into the cat gall bladder, the continuous fluid secretion into the lumen was inhibited by exogenous enkephalins. 4. Acetorphan, an enkephalinase inhibitor, was found to block fluid secretion by the inflamed gall bladder via a naloxone-sensitive mechanism, but not to affect fluid transport in the normal gall bladder. The drug also transiently contracted the gall bladder and increased bile outflow from the liver. 5. It is suggested that acetorphan, by reducing the degradation of endogenous enkephalins in the inflamed gall bladder, decreases fluid secretion by the epithelium and that enkephalinase inhibitors may find clinical applications in acute cholecystitis.

Animals↗
PubMed1989

Flow resistance in the feline choledocho-duodenal sphincter as studied by constant-pressure and constant-perfusion techniques.

During interdigestive periods, there is a resistance to flow in the biliary tract exerted by the sphincter of Oddi, resulting in a pressure gradient between the common bile duct and the duodenum. In this experimental study, this flow resistance was studied with both a constant-flow and a constant-perfusion technique in fasted, anaesthetized cats. The flow resistance exerted by the sphincter is higher when it is perfused by a constant flow compared to when the common bile duct pressure is kept constant and the flow varies in response to its muscular activity. It was demonstrated with each method that the flow resistance in the choledocho-duodenal junction is reduced in response to distension of the biliary tree and gallbladder and also by distension of the duodenum. Cholecystokinin was shown to reduce the flow resistance in the choledocho-duodenal junction as estimated with either method.

Ampulla of Vater↗