Karl-Gösta Ljungström

The Incidence of Clinical Postoperative Thrombosis After Gastric Surgery for Obesity During 16 Years

Background: Suggested risk factors for postoperative thrombosis such as high fatty acid levels, hypercholesterolemia and diabetes are common in obese patients. Methods: In a retrospective study, the case records of 328 patients operated for obesity by gastric procedure from September 1977 until December 1993 were analyzed: 253 women and 75 men with a mean age of 38 years and a mean body mass index (BMI) of 44 kg/m2. The operation time, use of epidural anesthesia, and the occurrence of risk factors; fatty acid levels, hypercholesterolemia and diabetes were recorded. Symptomatic thromboses were verified by phlebography or phylethysmography and pulmonary embolism with ventilation/perfusion scintigraphy or autopsy. Results: The mean operating time was 128 minutes, 77% had epidural anesthesia and the mean hospital stay was 12.3 days. The long hospital stay was due to the fact that most patients took part in different scientific studies perioperatively. The incidence of thromboembolism was 2.4%. Four patients ad pulmonary embolism, in one of them this was fatal. Three patients had deep leg vein thrombosis and one patient had arm thrombosis secondary to a central venous catheter. None of these patients had high fatty acids, catheter. None of these patients had high fatty acids, diabetes or high cholesterol. Of the patients, 298 were given dextran-70 (Macrodex®, Pharmacia) as prophylaxis, seven were given heparin and 23 were given no prophylaxis. In the patient group without diagnosed thrombosis, 31% had high fatty acid levels, 2% had high cholesterol levels and 9% had diabetes. Conclusions: Obese patients seem to have a moderate risk of developing postoperative thrombosis when an effective prophylaxis is used. High free fatty acids, hypercholesterolemia and diabetes are not obvious extra risk factors in obese patients. Thromboprophylaxis should be given to all operated obesity patients regardless of age. The surgeons must be aware and investigate promptly any symptoms suggestive of thromboembolism.

Safety of Dextran in Relation to Other Colloids – Ten Years Experience with Hapten Inhibition

OBJECTIVE The effects of hapten inhibition with dextran 1 (molecular weight: 1,000 D, Promit), which is in use since 1982 for the prevention of severe dextran-induced anaphylactic reactions (DIAR) caused by immune complexes, were studied. DESIGN Spontaneous reports to the manufacturer and to the WHO database INTDIS regarding adverse reactions to clinical dextran after preinjection of dextran 1 and to dextran 1 alone were collected from 1983 to 1992. During this period a total of 5.1 million doses of dextran 1 were sold in 15 countries. INTERVENTIONS Analysis of pre- and post-reaction titers of dextran-reactive antibodies (DRA) was made in most Scandinavian reports. RESULTS The incidence of severe DIAR (grades III-V) to clinical dextran after the prophylactic use of hapten inhibition was approximately 1/200,000 patients receiving dextran 1. In Sweden, where reporting of severe adverse drug reactions is mandatory, the incidence was approximately 1/70,000, indicating a 35-fold reduction. Only 2 fatal reactions were reported, an incidence of 1/2.5 million doses, indicating a 90-fold reduction. Both these occurred in patients with extremely high titers of DRA. Side effects to dextran 1, mostly mild, were reported in approximately 1 case per 100,000 doses. These side effects were not antibody mediated. CONCLUSIONS The above findings, together with other recent safety profile data, suggest that dextran with hapten inhibition has possibly become the safest plasma substitute in current clinical practice.

Effects of desmopressin on blood loss in hip arthroplasty. Controlled study in 50 patients.

50 patients undergoing elective total hip replacement under epidural anesthesia and dextran infusion were given two doses of the vasopressin analogue desmopressin 0.3 micrograms/kg BW or placebo in a double-blinded randomized prospective study. Intraoperative blood loss and drainage loss did not differ significantly between groups, but desmopressin reduced the mean total blood loss (calculated from hemoglobin decrease and blood transfusions) by 310 mL (P less than 0.05).

Clinical relevance of the fibrinogen uptake test in patients undergoing elective general abdominal surgery—relation to major thromboembolism and mortality

Postoperative thromboembolic complications were evaluated in 2578 patients undergoing elective abdominal surgery, all receiving prophylaxis with low molecular weight heparin. A positive fibrinogen uptake test (FUT) developed in 217 patients (8.4%), while 37 patients (1.4%) had major thromboembolism (TE, defined as proximal deep vein thrombosis and/or pulmonary embolism, verified with phlebography, pulmonary scintigraphy or autopsy). In only 14% a positive FUT was associated with a major TE event. In 19% of the patients with major TE the FUT was negative. In multiple logistic regression the independent predictors for major TE were partially different from those for positive FUT. Thirty day mortality was 3.0%. There were significant associations between both positive FUT and major TE on one hand and mortality on the other (relative risks 2.4 and 5.8, respectively). FUT is not a good predictor of major TE. Both positive FUT and major TE indicate a significant risk of postoperative death.

Effects of desmopressin and dextran on coagulation and fibrinolysis in healthy volunteers

The effects of desmopressin and dextran on haemostasis and fibrinolysis were studied in four healthy volunteers. Both drugs were compared to placebo, each volunteer being subject to four experiments. Dextran 70 (30 g i.v.) moderately decreased VIII:C and vWF:Ag and slightly increased antithrombin III, also when haemodilution and diurnal variation were considered. Desmopressin (0.3 micrograms/kg BW i.v.), alone as well as in combination with dextran, increased VIII: C, vWF:Ag, protein C and tPA and decreased PAI-1. The combination of desmopressin and dextran stimulated coagulation and fibrinolysis and might be of relevance to surgical blood loss as well as to postoperative thromboembolism.

Thromboprophylaxis in Emergency Surgery

Except for hip fracture surgery, emergency surgery has been only exceptionally studied concerning thromboprophylaxis. There are, however, several reasons to believe the frequency to be fairly high and that the patient group would be in need of prophylaxis. This paper discusses various emergency situations and also gives the design for an ongoing controlled study on the effect of postoperative start of thromboprophylaxis with low molecular weight heparin in emergency abdominal surgery.

Histopathological lung changes in immune complex mediated anaphylactic shock in humans elicited by dextran

Severe dextran-induced anaphylactic reaction (DIAR) is being recognized as a form of immediate IgG mediated immune complex reaction. Support for this pathogenesis is found in the correlation between the titer of dextran-reactive antibodies of IgG class and the severity of the reaction. Autopsy records were reviewed in 27 certified cases of fatal DIAR. The most frequent macroscopic findings were dilatation of the right side of the heart and acute pulmonary stasis. Autopsy lung specimens were collected from 17 of these patients. In 15 of the 17 lung specimens pulmonary microemboli were found. The microemboli had the appearance of hyaline eosinophilic globules, and the lung vasculature also contained leukocytes, platelets and disintegrated erythrocytes. These findings show similarity to the findings in a monkey model of known IgG mediated anaphylaxis, and give further support to the proposed pathogenesis of severe DIAR.

Dextran excretion rate in desmopressin treated volunteers

Desmopressin, or DDAVP, the vasopressin analogue, can be used to reduce blood loss in patients with congenital and acquired hemostatic disorders (1) and also when such disorders have been induced by drugs used in relation with surgery (2). It is a potent antidiuretic drug, although there seems to be a physiological compensation of this effect in patients undergoing surgery (3). The polysaccharide dextran, which is used for plasma expansion and thromboprophylaxis, has an additive effect with desmopressin on the blood volume in healthy volunteers (3). Desmopressin does not impair the effect of dextran to prevent postoperative thromboembolism (4). In order to further elucidate possible desmopressin-dextran interactions we have studied how desmopressin affects the pharmacokinetics of dextran.

Does Vaccination of Splenectomized Patients against Pneumococci Induce Dextran-Reactive Antibodies?

Polyvalent pneumococcal vaccine containing polysaccharides from serotypes known to be cross-reactive with dextran was used for vaccination of 72 patients either shortly before or on the average 6.25 years after splenectomy. The titer of dextran-reactive antibodies was determined by passive hemagglutination before as well as 6 weeks and 6 months after vaccination. Already prior to vaccination the patients had moderately elevated titers of these antibodies and the titer was somewhat reduced during the study period. Small intergroup differences were observed but the titers of patients who had received cytostatic and/or radiation therapy did not appear to react differently to vaccination. It is concluded that this type of vaccine does not induce dextran-reactive antibodies when given to asplenic individuals.