Acta chirurgica Scandinavica. Supplementum最新文献

Central and renal hemodynamics, renal oxygenation, renal uptake of glucose, lactate, fats, renal carnitine metabolism, arterial atrial natriuretic factor (ANF) and catecholamine release were studied in sixteen adult beagle dogs during pentobarbital anesthesia. Renal cortical oxygen tension was recorded by means of a Silastic tonometer. Twelve animals underwent acute circulatory shock induced by intravenous Escherichia coli endotoxin 0.5 mg/kg. Four control dogs received normal saline. The endotoxin infusion resulted in decreased cardiac function, renal blood flow and renal cortical PO2. The renal venous PO2 increased during the experiment. Arterial and renal venous glucose concentrations increased transiently during endotoxemia. Circulating lactate concentrations increased significantly whereas the arteriovenous lactate difference remained almost unchanged. Renal uptake of lactate and glucose were not influenced during the moderate renal hypoperfusion caused by endotoxin. Arterial free fatty acid (FFA) concentrations increased significantly 2 hours after onset of the endotoxin infusion whereas renal venous FFA levels remained rather stationary. The renal uptake of FFA increased with increasing arterial FFA concentrations. Circulating free carnitine concentrations increased significantly in endotoxin shock. Blood acyl-carnitine concentrations remained essentially unchanged. Carnitine concentrations declined significantly in endotoxic renal tissue. The arterial concentrations of ANF, epinephrine, norepinephrine and the norepinephrine metabolite 3,4-dihydroxyphenylglycol (DHPG) increased in plasma during early endotoxemia. The levels of these hormones remained very low and constant in the controls. To summarize, endotoxin injection resulted in impaired renal perfusion and oxygenation, increased uptake of free fatty acids and unchanged uptake of glucose, lactate, glycerol and triglycerides. Decreased renal carnitine concentrations were observed. Arterial plasma concentrations of ANF and catecholamines increased in endotoxin shock.

Unfractionated heparin in the extrinsic system has an action on prothrombinase that is insignificant compared to its antithrombin action. In the intrinsic system, unfractionated heparin does have an indirect antiprothrombinase action because its antithrombin activity inhibits the feedback activation of Factor VIII. Most low molecular weight heparins are not different from unfractionated heparin, although their antiprothrombinase action may be slightly higher. Among these, enoxaparin has the highest antiprothrombinase action, due to a relatively high content of very low molecular weight material. In platelet rich plasma, there is an important difference between unfractionated and low molecular weight heparin in that, up to 0.3 U/ml, unfractionated heparin is completely neutralized by activated platelets (300,000 microliters/l) whereas low molecular weight heparins are not. Therefore, unfractionated heparin in platelet rich plasma acts only on the lag phase of thrombin production and not on the amount of thrombin produced. Low molecular weight heparins significantly prolong the lag time and inhibit the thrombin peak in platelet rich plasma.

The colectomy rate in patients with ulcerative colitis has increased during the last 30 years in Stockholm County due to increased incidence and a more liberal attitude to colectomy in acute cases. In an area of Stockholm's size, about 30 patients with UC will require colectomy every year and of these, 12 will be acute cases. The main factor affecting the colectomy rate was the extent of disease at diagnosis. The 25-year cumulative colectomy rate was 65% in patients with total colitis compared to 45% in all patients. The probability of undergoing a colectomy decreased as the duration of disease increased and after five years duration of disease the colectomy rate was about 1% per year. The choice of primary surgical procedure has changed during the study period and subtotal colectomy and ileostomy is now preferred as the surgical procedure of choice, both in acute and elective cases. The frequency of major complications was constant during the period of study but increased with the urgency of intervention, being 25% in elective cases and 46% in acute cases. The overall postoperative mortality fell from 13% during 1960 to 1964 to 2% during 1980-1984. In acute cases the mortality during the same time periods decreased from 36% to 3%. The long-term results of ileorectal anastomosis showed a substantial failure rate and the most common cause of failure was recurrent rectal disease. In patients who still had their ileorectal anastomosis at the time of follow-up the functional results were better than for the pelvic pouch. The ileorectal anastomosis is for some patients a definite solution and in others it avoids or delays an ileostomy and at the same time still permits a pelvic pouch at a later date. The need for secondary surgery after colectomy for UC is great. The cumulative probability of a fist small intestinal obstruction requiring surgery in 483 patients treated by colectomy was 23% after 15 years. The annual incidence was highest in patients treated by pelvic pouch and lowest in patients treated by IRA. The cumulative probability of a first ileostomy revision was 21% after 15 years. In patients with a Kock's pouch the cumulative probability of a first nipple revision was as high as 52% after two years. The need for secondary surgery was initially high in patients treated by pelvic pouch but the need has decreased during the latter years due to improved technique and increasing surgical experience.(ABSTRACT TRUNCATED AT 400 WORDS)

Interest in low molecular weight heparins as potential antithrombotic agents has been stimulated by two observations. These were that low molecular weight heparins have a different anticoagulant profile from unfractionated heparin and that some low molecular weight heparins are less haemorrhagic in animal models than unfractionated heparins for equivalent antithrombotic effects. Subsequently, it was shown that low molecular weight heparins inhibit platelet function and impair vascular permeability less than unfractionated heparin and that low molecular weight heparins have a longer biological half-life than unfractionated heparin. A number of low molecular weight heparins have been evaluated in clinical trials in general surgery, orthopaedic surgery and in the treatment of venous thrombosis. Low molecular weight heparins are highly effective in orthopaedic surgery where they appear to be more effective than unfractionated heparin. Low molecular weight heparins have also been shown to be either as effective or more effective than unfractionated heparin in preventing post-operative thrombosis following general surgery. In preliminary studies, low molecular weight heparins appear to be as effective as unfractionated heparin in the treatment of venous thrombosis but larger studies are required using clinically relevant outcome measures.