Coagulation changes and edema formation during long-distance bus travel

Long-distance travel in a cramped position by aircraft or by bus and car has been suggested to be associated with an increased risk for thromboembolic events. Recently, we demonstrated moderate activation of coagulation after a long-haul flight. At present the single contributing factors (i.e. hypoxia and low humidity on board an aircraft and prolonged sitting in an aircraft, car or bus inducing venous stasis) have not yet been investigated. Therefore we measured markers of coagulation and fibrinolysis as well as functional parameters of coagulation using activated thrombelastography in 19 healthy volunteers before, during and after a real 10-h bus journey. In addition, changes in leg volume were measured. Thrombelastography revealed moderate activation of coagulation in all travelers, which was accompanied by a significant increase in prothrombin fragment F1 + 2. Thrombin-antithrombin III complexes and D-dimer remained unchanged, and tissue-type plasminogen activator and plasminogen-activator inhibitor 1 decreased after travel. After the travel we found a significant increase in leg volume that was exclusively distributed in the calf. We conclude that beside long-haul flights also long-distance bus travel induces a certain activation of the coagulation system. Thus, it is questionable whether hypoxia is the crucial risk factor for thromboembolic events after long-haul flights.

The effects of perioperatively administered crystalloids and colloids on concentrations of molecular markers of activated coagulation and fibrinolysis

To explore whether intravenous administration of routinely used crystalloid or colloid solutions differently affects the coagulation system, we investigated orthopaedic patients. Since crystalloid solutions might cause hypercoagulability, we here present our results on molecular markers of coagulation and fibrinolysis. Patients undergoing knee replacement surgery randomly received isovolemic amounts of lactated Ringer's solution, 6% hydroxyethyl starch 200/0.5 or 4% modified gelatine. Arterial blood samples for determination of specific molecular markers of activated coagulation (thrombin/antithrombin complex, D-dimer, prothrombin fragment F1 + 2), fibrinolysis (plasmin/alpha 2-antiplasmin complex, tissue plasminogen activator, plasminogen activator inhibitor-1), and concentrations of coagulation factor XIII were obtained at baseline, before tourniquet release, at the end of surgery and 2 h after operation. During the observation period, thrombin/antithrombin complex increased from 4.8 to 54.7 microg/l, D-dimer increased from 0.3 to 6.0 mg/ml, prothrombin fragment F1 + 2 increased from 1.7 to 5.9 nmol/l, tissue plasminogen activator decreased from 7.3 to 6.7 ng/ml, plasminogen activator inhibitor-1 increased from 68.4 to 71.0 ng/ml, plasmin/alpha 2-antiplasmin complex increased from 281.5 to 884 microg/l and factor XIII decreased from 89.0 to 58.5%. All parameters changed significantly but without any detectable difference in the response profile between the groups receiving different intravenous fluids. During knee replacement surgery a pronounced activation of the coagulation/fibrinolytic system was observed, regardless of whether patients received crystalloid or colloid fluids. Thus, these results cannot confirm the hypothesis that crystalloid fluids per se cause hypercoagulability in vivo.

Continuous administration of heparin in patients with deep vein thrombosis can increase plasma levels of diamine oxidase

Besides its anticoagulant activity, the sulfated polysaccharide heparin has numerous other biological effects. Especially the antiinflammatory and immunoregulatory properties of heparin may be associated with its ability to release the histamine-degrading enzyme diamine oxidase (DAO) from tissue-bound sites into the circulation. Whereas DAO activity is at the limits of detection in normal human plasma, the application of heparin leads to a significant increase of plasma DAO activity. However, previously, only the effect of bolus injection of unfractionated heparin (UFH) had been studied. To investigate DAO release during continuous heparin infusion, 28 patients with deep vein thrombosis (DVT) undergoing heparin therapy were analyzed. Whereas continuous heparin infusion did not lead to any increase of plasma DAO activity in 12 patients (43%), 6 patients (21%) showed a single elevated and 10 patients (36%) permanently elevated plasma DAO activity. The groups of patients exhibiting different DAO release responses did not differ in age, sex, body weight, concomitant diseases, heparin infusion rates, coagulation indices, location and extension of thrombosis, or clinical outcome. However, the rate of idiopathic DVT was significantly higher in the group of patients releasing DAO. This study shows, for the first time, that continuous heparin infusion can lead to DAO release and that individuals exhibit considerable differences in their release response. Although the significance of heparin-induced DAO release needs further clarification, our results indicate that postheparin plasma DAO activity could be an interesting parameter correlated with idiopathic DVT.

Formation of edema and fluid shifts during a long-haul flight

BACKGROUND

More than 1.5 billion passengers travel by aircraft every year. Leg edema, as a sign of venous stasis, is a well-known problem among passengers during and after long-haul flights. Until now, no studies have been done on the development of leg edema and fluid shifts under real flight conditions. The aim of our study was to evaluate edema formation in the leg and to investigate possible fluid shifts to the interstitial space under real flight conditions.

METHODS

Twenty participants, 10 without risk and 10 with moderate risk for venous thrombosis, were selected. They flew from Vienna to Washington, flight time 9 h, and returned 2 days later. Investigations were done 48 h before the flight, between the fifth and eighth flight hour on board to Washington and back to Vienna, immediately after arrival in Vienna, and 1 and 3 days after arrival. Plethysmographic measurements were carried out using an optoelectronic scanner system (Perometer). Thickness of the skin was measured at the forehead and in front of the tibia.

RESULTS

There were no differences in all measurements between both groups. The volume of the leg increased from 8242 +/- 1420 mL to 8496 +/- 1474 mL after the flight (p <.001). Volume accumulation was distributed to the lower leg as well as to the thigh. Skin thickness in front of the tibia increased significantly during the flight (p <.05), and remained elevated 1 day after arrival.

CONCLUSION

We have demonstrated that long-haul flights induce significant fluid accumulation in the lower extremity, involving the lower leg and thigh. This increase in tissue thickness was maintained for some days after the flights.

Serum levels of cartilage oligomeric matrix protein. A predicting factor and a valuable parameter for disease management in rheumatoid arthritis

OBJECTIVE

To examine whether cartilage oligomeric matrix protein (COMP) correlates with inflammation and/or joint destruction of patients with rheumatoid arthritis (RA) and to test COMP as predicting factor for the outcome of patients with established RA.

METHODS

Serum levels of COMP were measured in sera of 62 patients, suffering from RA according to the ACR criteria and treated in intervals in our department, over a period of 5 years. A commercially available sandwich--type ELISA-kit developed by AnaMar Medical AB, Sweden, was used. The results of serum COMP were compared with the Disease Activity Score (DAS), the Larsen Score, and clinical and laboratory parameters.

RESULTS

We found a positive correlation between serum levels of COMP at baseline and deterioration of Larsen score even after 5 years (p < 0.007; r = 0.34). To confirm serum COMP as an independent predicting factor for patients with RA we looked at a subgroup of patients (n = 17) with elevated serum levels of COMP (mean 11,7 U/l) and low clinical prognostic factors. In this subgroup we also found a significant correlation with delta Larsen score (p < 0.01; r = 0.59) after 5 years.

CONCLUSION

Serum levels of COMP is known to reflect increased cartilage turnover. The results indicate that serum COMP may be used as a prognostic marker of cartilage degradation in a patient group with established RA.

Prevention of severe ovarian hyperstimulation syndrome (OHSS) in IVF patients by steroidal ovarian suppression--a prospective randomized study

Ovarian hyperstimulation syndrome (OHSS) is the major complication associated with artificial reproductive technologies. The aim of this study was to assess the potential of exogenous steroids to prevent OHSS without adversely affecting pregnancy rate. A prospective and randomized study including 945 consecutive cycles in 603 women (mean age 28.6 years) was carried out to evaluate the efficiency of high-dose progesterone and oestradiol administration during the luteal phase to prevent OHSS. After ovulation induction, patients were allocated by a series of computer-generated random numbers to receive either 5000 iu human chorionic gonadotrophin (hCG) 4 and 8 days after embryo transfer (group 1, n = 534) or 500 mg hydroxy-progesterone caproate and 10 mg oestradiol valerate on days 2, 6, 10 and 14 after embryo transfer (group 2, n = 411), by i.m. injection. Total pregnancy rate was 24% (97 of 411) and 23% (121 of 534), and median serum progesterone concentrations on day 15 after embryo transfer were 5.8 ng ml(-1) (range 0.1-298) and 0.1 ng ml(-1) (range 0.1-372) in groups 1 and 2, respectively (P = 0.001). One hundred and sixty-three (30.5%) women in group 1 and 22 (5.4%) women in group 2 developed signs of OHSS (P < 0.0001). These results indicate that steroidal ovarian suppression during the luteal phase is a promising tool to reduce the incidence and severity of OHSS in a high-risk population without compromising the pregnancy rate.

Prospective multicentre trial comparing the efficacy of, and compliance with, glimepiride or acarbose treatment in patients with type 2 diabetes not controlled with diet alone

AIM

To determine the efficacy of, and compliance with, glimepiride or acarbose in patients with Type 2 diabetes.

METHODS

Two hundred and nineteen patients with Type 2 diabetes uncontrolled by diet alone were randomized to receive either glimepiride (1, 2, 3, 4 or 6 mg once daily, n = 111) or acarbose (50, 100, 150 or 200 mg 3 times daily, n = 108). Both drugs were titrated in a 6-week dose-finding phase to achieve a fasting blood glucose (FBG) concentration < or = 7.8 mmol/ (140 mg/dl). Patients achieving this target entered a 20-week treatment period. Efficacy was assessed by responder rate, number of patients achieving a FBG of < or = 7.8 mmol/l, HbA1c, blood glucose concentrations in response to a standard breakfast, body weight and compliance.

RESULTS

Glimepiride was associated with a significantly greater responder rate than acarbose (61 vs 34%, p < 0.001), significantly greater decreases in HbA1c (2.5 +/- 2.2% vs 1.8 +/- 2.2%, p = 0.014) and FBG (2.6 +/- 2.6 mmol/l vs 1.4 +/- 2.8 mmo/l, p = 0.004), a decreased glucose response to breakfast compared with acarbose [area under curve (AUC) end: 8.9 +/- 2.7 mmol/l vs 11.3 +/- 3.9 mmol/l, p = 0.0001], and was accompanied by significantly greater compliance (91 < or = 12% vs 66 +/- 26%, p = 0.0001). Weight loss during the study was observed in both the acarbose group (1.9 +/- 3.9 kg, p = 0.001) and glimepiride group [0.4 +/- 5.2 kg, p = 0.8 (NS)].

CONCLUSIONS

Improved efficacy and greater compliance were observed in response to treatment with glimepiride compared with acarbose, in patients with Type 2 diabetes.

Effects of glimepiride on HbA(1c) and body weight in Type 2 diabetes: results of a 1.5-year follow-up study

Sulphonylureas are effective and well tolerated in patients with Type 2 diabetes, but may be associated with weight gain, and lack of compliance due to multiple daily dosing. This open, uncontrolled surveillance study examined the efficacy and safety of glimepiride, a new sulphonylurea, administered once daily in patients with Type 2 diabetes. A total of 1,770 patients were enrolled in the study, and 284 patients were selected for follow-up. Patients received 0.5 to >4 mg glimepiride once daily for 1.5 years. HbA(1c) was reduced from 8.4% at baseline to 7.1% after 4 months and 6.9% after 1 and 1.5 years (median intra-individual change from baseline: -1.4, -1.5, and -1.7%, respectively; P<0.0001). Treatment with glimepiride also resulted in significant and stable weight loss relative to baseline, with the exception of patients with a body mass index of <25 kg/m(2). Mean body weight was reduced from 79.8 kg at baseline to 77.9 kg after 4 months, 77.2 kg after 1 year, and 76.9 kg after 1.5 years (mean intra-individual change from baseline: -1.9 kg, P<0.0001; -2.9 kg, P<0.05; -3.0 kg, P<0.005, respectively). Therefore, once daily glimepiride provides effective glycaemic control, and may have advantages over other sulphonylureas, because it exhibits weight neutralizing/reducing effects in patients with Type 2 diabetes.

Plasma amine oxidase: a postulated cardiovascular risk factor in nondiabetic obese patients

Increased activity of semicarbazide-sensitive plasma amine oxidase (SSAO), an enzyme converting various amines, has been implicated in the generation of endothelial damage through formation of cytotoxic reaction products. We investigated if SSAO activity is elevated in morbidly obese patients, which might contribute to the increased cardiovascular risk associated with obesity. SSAO activity was determined in 74 nondiabetic, obese patients (median body mass index [BMI]: 42.9 kg/m(2)) and in 32 healthy, non-obese controls (median BMI: 23.3 kg/m(2)) using a radiometric assay based on the conversion of [(14)C]benzylamine. SSAO and parameters of glucose and lipid metabolism were compared for subgroups of obese patients with normal (n = 49) and impaired (n = 25) glucose tolerance using nonparametric statistical tests. Median SSAO activity was 434 microU/mL in obese patients, which was significantly higher than in healthy, non-obese controls (median SSAO activity: 361 microU/mL). Median SSAO activity in patients with normal and impaired glucose tolerance was 423 and 464 microU/mL, respectively. SSAO activity was not correlated with any other clinical or laboratory parameters characteristic of the metabolic alterations associated with obesity. Elevated SSAO activity is found in nondiabetic, morbidly obese patients and might be an interesting independent risk factor for obesity-related cardiovascular morbidity. Long-term follow-up of SSAO and its possible role in pathogenic events is warranted since intervention with specific SSAO inhibitors is available.

Vertical Mayo repair of midline incisional hernia: suggested guidelines for selection of patients

OBJECTIVE

To find out whether the vertical Mayo repair should be done for midline incisional hernias.

DESIGN

Retrospective study.

SETTING

University hospital, Austria.

SUBJECTS

208 patients who presented with a primary midline incisional hernia during the period January 1991 to December 1996.

INTERVENTIONS

Incisional hernia repair using the vertical Mayo technique.

MAIN OUTCOME MEASURES

Recurrence rates, risk factors, common practice.

RESULTS

There were 60 recurrences (29%) and median follow up was 6 years (range 4-8). Four risk factors (cirrhosis, chronic cough, obesity (BMI > 30), and hernia width > 4 cm) were identified, which were independently predictive of hernia recurrence. All 60 patients with a recurrent hernia had at least two of the four risk factors. The remaining 148 patients who did not develop a recurrence had no risk factors, or only one. Recurrence could therefore be predicted with a sensitivity of 80% and a specificity of 96%.

CONCLUSION

The vertical Mayo repair is a good method for the repair of incisional hernias if not more than one of the four significant risk factors is present. The presence of two or more risk factors is predictive of a high rate of recurrence, and other techniques, such as alloplastic mesh repair, should be considered.

Austrian Moderate Altitude Study (AMAS 2000) - fluid shifts, erythropoiesis, and angiogenesis in patients with metabolic syndrome at moderate altitude (congruent with 1700 m)

It was hypothesized that subjects with metabolic syndrome (hypertension, obesity, hyperlipidemia, diabetes mellitus): (1) develop measurable peripheral edema at moderate altitude and (2) might show differences on erythropoiesis, iron status and vascular endothelial growth factor (VEGF) in comparison to healthy subjects during and after a long-term stay (3-week exposure) at moderate altitude (congruent with 1700 m). Twenty-two male subjects with metabolic syndrome were selected. Baseline investigations (t1) were performed in Innsbruck (500 m). All participants were transferred by bus to 1700 m (Alps) and remained there for 3 weeks with examinations on day 1 (after the first night at altitude, t2), day 4 (t3), day 9 (t4) and day 19 (t5). After returning to Innsbruck, post-altitude examinations were conducted after 7-10 days (t6) and 6-7 weeks (t7), respectively. Body mass was decreased from t1 to t7 (P<0.01). Total body water was decreased at t2 (P<0.01), returned to control level (t3, t4), and was found elevated at t7 (P<0.01). Lean body mass did not change, but body fat decreased during the study (P<0.01). Tissue thickness at the forehead decreased during and after altitude exposure (P<0.01), whereas tissue thickness at the tibia did not alter. Erythropoietin (EPO) was elevated as early as t2 and remained increased until t5. Reticulocyte count was increased at t3 and remained above pre-altitude values. VEGF levels were unchanged. After a 3-week exposure to moderate altitude, patients with metabolic syndrome had reduced their body mass, mainly because of a reduction in body fat. The moderate altitude was found to stimulate erythropoiesis in these patients but this was not sufficient to increase serum VEGF concentration.

Austrian Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1,700 m) on cardiovascular and metabolic variables in patients with metabolic syndrome

We investigated the changes in the cardiovascular system [resting blood pressure (BP) and heart rate (HR), measured by means of a 24-h ambulatory BP and a holter-electrocardiogram (ECG)], glycemic parameters, and lipid metabolism of subjects suffering from metabolic syndrome during a 3-week sojourn at 1,700 m in the Austrian Alps. A total of 22 male subjects with metabolic syndrome were selected. Baseline investigations were performed at Innsbruck (500 m above sea level). During the 3-week altitude stay the participants simulated a holiday with moderate sports activities. Examinations were performed on days 1, 4, 9, and 19. After returning to Innsbruck, post-altitude examinations were conducted after 7-10 days and 6-7 weeks, respectively. The 24-h ambulatory BP and holter ECG revealed a decrease in average HR, BP, and rate pressure product (RPP: systolic blood pressure x HR) after 3 weeks of altitude exposure. In some patients, an increase in premature ventricular beats was observed at the end compared to the beginning of the exposure to moderate altitude. The ECG revealed no ischemic ST-segment changes. Maximal physical capacity as measured by symptom-limited maximal cycle ergometry tests remained unchanged during the study. Six weeks after the altitude exposure the blood pressure increased again and returned to pretest levels. The Homeostasis Model Assessment index, which is a measure of insulin resistance, decreased significantly and glucose concentrations obtained after an oral glucose tolerance test were significantly lower after the stay at altitude compared to the basal values. We conclude that after a 3-week exposure to moderate altitude, patients with metabolic syndrome (1) tolerated their sojourn without any physical problems, (2) exhibited short-term favorable effects on the cardiovascular system, and (3) had significant improvements in glycemic parameters that were paralleled by a significant increase in high-density-lipoprotein-cholesterol.

Splenectomy versus medical treatment for idiopathic thrombocytopenic purpura

BACKGROUND

Treatment strategies for idiopathic thrombocytopenic purpura (ITP) are still uncertain and its management is primarily empirical. The aim of this study was to investigate the role of splenectomy in the therapy of ITP and to evaluate whether medical or surgical treatment is superior.

METHODS

Ninety-two patients with ITP were included in the study. All of these patients had medical therapy and 38 of them underwent splenectomy subsequently. Follow-up was completed in 91 patients after a median of 64 months.

RESULTS

Side effects of medical therapy were noticed in 32 patients (35%), whereas after surgery only 2 patients (5%) had minor complications. A complete or partial remission was achieved in 35 patients (92%) after splenectomy, whereas this was achieved in only 27 patients (30%) after medical therapy. On multivariate analysis splenectomy and age were the only significant independent factors for complete and partial remission.

CONCLUSIONS

Splenectomy is highly effective and safe in the treatment of ITP and is superior over medical therapy. These results should stimulate the discussion about splenectomy for ITP, possibly establishing evidence-based guidelines for surgical treatment in hematology.

Influence of antithrombin on ischemia/reperfusion injury in the isolated blood-free perfused rat heart

INTRODUCTION

Antithrombin (AT) is well known as an important inhibitor of the coagulation system. An interesting new hypothesis is that antithrombin exerts specific anti-inflammatory effects by stimulating the production of prostacyclin in endothelial cells. Recent studies report beneficial influence on ischemia/reperfusion injury in several organs. These effects are independent of the coagulation system. We investigated the influence of antithrombin on ischemia/reperfusion injury and prostacyclin release in the isolated rat heart. Since the perfusion of the hearts was without blood, the used model essentially describes effects of antithrombin on endothelial cells.

MATERIAL AND METHODS

Experiments were performed using the temperature-controlled and pressure-constant Langendorff apparatus. The hearts of 32 male Sprague-Dawley rats were subjected to 20 min of global ischemia followed by 30 min of reperfusion. Antithrombin was administered in three different concentrations (1, 4 and 8 U/ml) 15 min prior to global ischemia. Cardiac contractility parameters and biochemical parameters were measured.

RESULTS

Treatment with antithrombin did not increase the release of prostacyclin significantly after ischemia. Antithrombin at a concentration of 8 U/ml led to a significant increase in creatine kinase (CK; p<0.05) and troponin I (p<0.05), whereas measurements of lactate dehydrogenase (LDH) revealed no significant differences between treated and untreated hearts.

CONCLUSION

Our study shows that antithrombin did not reduce ischemia/reperfusion injury in the isolated heart, and prostacyclin is not significantly released following antithrombin treatment. High concentrations of antithrombin, however, might have a negative influence on the reperfused heart. The underlying mechanism remains unclear.

Changes of biochemical markers and functional tests for clot formation during long-haul flights

INTRODUCTION

Long-haul flights have been suggested to be associated with an increased risk for thromboembolic events. Until now, changes in the coagulation system during an actual flight have not been investigated.

MATERIALS AND METHODS

To explore whether any changes occur in the coagulation system during a real long-haul flight molecular markers for coagulation and fibrinolysis were measured in 20 volunteers (10 subjects with a low and 10 with a moderate risk for venous thromboembolism (VTE)) during and after a return flight from Vienna to Washington. In addition, functional measurements of coagulation were performed using activated thrombelastography.

RESULTS

Thrombelastographic measurements revealed activation of coagulation in all passengers, who showed an increased activity of FVII and FVIII as well as suppressed fibrinolysis. There was no evidence of a pronounced thrombin and fibrin formation. We did not find any differences between both groups concerning coagulation changes.

CONCLUSION

Long-haul flights induce a certain activation of the coagulation system. This activated coagulation could be a risk factor for VTE during long-haul flights mainly when other risk factors are present.

The effects of perioperatively administered colloids and crystalloids on primary platelet-mediated hemostasis and clot formation

To explore whether routinely administered colloids and crystalloids influence the hemostatic system, we studied 60 patients undergoing knee replacement surgery during randomized intravascular fluid administration using 6% hydroxyethyl starch 200/0.5 (HES) or 4% modified gelatin (GEL) in addition to a basal infusion of lactated Ringer's solution (RL), or exclusively RL. In addition to routine coagulation tests, measurements of coagulation factors were performed. Also, functional measurements of the in vitro bleeding time by use of the platelet function analyzer (PFA-100 and ROTEG analysis (ROTEG(R); extrinsically and intrinsically [Ex; In] activated measurements of clotting time, CT [s]; clot formation time, CFT [s]; clot strength, A20 [mm]; fibrinogen component of the clot, FibA20 [mm]; and maximal clot elasticity) were used. Time dependency of variables was analyzed with a repeated-measures analysis of variance (all groups pooled); differences between groups were detected by comparing the calculated area under the curve (AUC(A-D)). For all variables, except ExCT, ExCFT, and InCFT, a significant time dependency was demonstrated, indicating that impaired platelet-mediated hemostasis and clot formation occurred with IV administration of fluids. Total clot strength, fibrinogen part, and clot elasticity decreased significantly more in the colloid groups than in the RL group (InA20: HES, -13.0 mm; GEL, -11.5 mm; RL, -1.3 mm; P = 0.042; FibA20: HES, -10.5 mm; GEL, -6.0 mm; RL, -1.3 mm: P < 0.0001; MCE: HES, -48; GEL, -35; RL, -15.8; P < 0.0001). The decrease in fibronectin concentrations was significantly smaller with GEL as compared with HES, whereas a weak trend toward a larger decrease in fibrinogen concentrations was observed with both colloids. Results show that colloid administration reduces final clot strength more than does RL alone, which also exhibited effects, albeit minor, on the coagulation system. The reduction in total clot strength was due to impaired fibrinogen polymerization, resulting in a decreased fibrinogen part of the clot and reduced clot elasticity.

IMPLICATIONS

Our data suggest that during deliberate colloid administration, critically impaired fibrinogen polymerization and reduced fibrinogen concentrations might be reached earlier than expected. Therefore, maintaining fibrinogen concentrations seems essential when continuing blood loss is bridged by colloid infusion until transfusion triggers are reached, especially in patients already exhibiting borderline fibrinogen levels at baseline.

The effect of the combined administration of colloids and lactated Ringer's solution on the coagulation system: an in vitro study using thrombelastograph coagulation analysis (ROTEG

Gelatin solutions are often given in clinical practice once the maximal dose of a median-weight hydroxyethyl starch (HES) has been reached. Colloids are usually combined with lactated Ringer's solution (RL). Whether the combined administration of colloids and/or crystalloids affects blood coagulation is not known. We diluted blood by 20%, 40%, and 60% with RL, gelatin (Gelofusin), 6% HES 130/0.4 (Voluven), and 6% HES 200/0.5 (Iso-Hes), as well as with combinations of these solutions at a ratio of 1:1 (gelatin/RL, 6% HES 130/0.4:RL, 6% HES 200/0.5:RL, 6% HES 130/0.4:gelatin, 6% HES 200/0.5:gelatin). Thereafter, blood was analyzed by using modified thrombelastograph coagulation analysis (ROTEG) and clotting time, clot formation time, and maximal clot firmness were determined. RL had the least effect on hemostasis. Gelatin administered alone impaired the coagulation system significantly less than each median-weight HES administered alone. We conclude that gelatin combined with 6% HES 200/0.5 or 6% HES 130/0.4 decreases hemostasis <6% HES 200/0.5 or 6% HES 130/0.4 administered alone.

IMPLICATIONS

The effect of the combined administration of different colloids and/or crystalloids on coagulation is not known. We show that hemostasis is less impaired using a combination of gelatin and median-weight starches than using median-weight starches alone. Furthermore, the combination of lactated Ringer's solution and gelatin decreases the coagulation system to the same extent as the combination of lactated Ringer's solution and 6% hydroxyethyl starch 130/0.4.

Antifactor Xa activity in intensive care patients receiving thromboembolic prophylaxis with standard doses of enoxaparin

BACKGROUND

Low-molecular-weight heparins (LMWHs) have become increasingly used to prevent thromboembolic complications in intensive care patients. Unlike in medical and surgical patients, no data on the anticoagulant effectiveness of standard LMWH dosages exist in intensive care patients. Therefore, we prospectively investigated antifactor Xa (aFXa) levels after subcutaneous administration of 40 mg of enoxaparin in 89 intensive care patients over a 24-h period.

METHODS

AFXa levels were measured before, 4, 12 and 24 h after subcutaneous administration of enoxaparin. Laboratory parameters including prothrombin time, activated partial thromboplastin time, antithrombin III, fibrinogen as well as platelet count were collected at same intervals. Demographics included age, sex, height, weight, body mass index, admission diagnosis, a thromboembolic risk score and a modified Goris multiple organ dysfunction score.

RESULTS

At 4, 12 and 24 h, 56.5%, 39.3% and 12.6% of the study patients were within recommended antithrombotic aFXa levels (0.1-0.3 U ml(-1)). Presence of multiple organ dysfunction as well as high body weight were significantly correlated with low aFXa levels.

CONCLUSION

European standard dosages of 40 mg of enoxaparin once daily proved to be ineffective in achieving recommended antithrombotic aFXa levels in intensive care patients. This was most pronounced in patients with high body weight and presence of multiple organ dysfunction.

Are leukocytes in salvaged washed autologous blood harmful for the recipient? The results of a pilot study

To explore whether polymorphonuclear leukocytes (PMNL) are activated to the priming threshold through intraoperative blood salvage, and are thus able to induce endothelial damage, we investigated chemotactic response (n = 20) and respiratory burst (RB; n = 20) of PMNL without (basal respiratory burst, bPMNL-RB) and after in vitro stimulation with formyl-Met-Leu-Phe (fMLP-RB) and phorbol myristate acetate (PMA-RB). Blood was processed with a continuous autotransfusion device (CATS). Heparin (Heparin group) and sodium citrate (Citrate group) were used alternately as an anticoagulant for each half of the chemotaxis and RB studies. Comparison of measurements from the processed autologous erythrocyte concentrates (paEC) to pre- and intraoperative arterial blood samples showed no statistically significant difference for any test of PMNL functional responses in an orthopedic patient population. Analysis of intraindividual changes demonstrated a significantly increased bPMNL-RB (both groups, P = 0.0032; Heparin group, P = 0.0098), fMLP-RB (both groups, P = 0.0484; Citrate group, P = 0.0371), and PMA-RB (Citrate group, P = 0.002) in the paEC compared with intraoperative arterial samples, whereas the chemotactic response did not change. Nevertheless, median values of all RB measurements in the paEC were within the range of pre- and intraoperative values, indicating that PMNLs contained in the paEC are neither impaired nor activated to the priming threshold. The results confirm the clinical experience that intraoperative blood salvage is safe to use during major orthopedic surgery and questions the beneficial effect of special leukocyte-removing filters.

Blunted erythropoietic response to anemia in multiply traumatized patients

OBJECTIVES

To assess the relations between anemia, serum erythropoietin (EPO), iron status, and inflammatory mediators in multiply traumatized patients.

DESIGN

Prospective observational study.

SETTING

Intensive care unit.

PATIENTS

Twenty-three patients suffering from severe trauma (injury severity score > or =30).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood samples were collected within 12 hrs after the accident (day 1) and in the morning on days 2, 4, 6, and 9 to determine blood cell status, serum EPO, tumor necrosis factor-alpha (TNF-alpha), soluble tumor necrosis factor-receptor I (sTNF-rI), interleukin-1 receptor antagonist (IL1-ra), interleukin-6 (IL-6), neopterin, and iron status, respectively. Hemoglobin concentration was low at admission (mean, 10.0 g/dL; range, 6.8-12.9 g/dL) and did not increase during the observation time. Serum EPO concentration was 49.8 U/L (mean value) on day 1 and did not show significant increases thereafter. No correlation was found between EPO and hemoglobin concentrations. TNF-alpha remained within the normal range. sTNF-rI was high at admission and increased further. IL1-ra was above the normal range. IL-6 was very high at admission and did not decrease thereafter. The initial neopterin concentration was normal, but increased until day 9. Serum iron was significantly decreased on day 2 posttrauma and remained low during the study. Serum ferritin increased steadily from day 2, reaching its maximum on day 9. In contrast, concentrations of transferrin were low from admission onward.

CONCLUSIONS

Multiply traumatized patients exhibit an inadequate EPO response to low hemoglobin concentrations. Thus, anemia in severe trauma is the result of a complex network of bleeding, blunted EPO response to low hemoglobin concentrations, inflammatory mediators, and a hypoferremic state.

Selection of patients for laparoscopic antireflux surgery

Since the first laparoscopic fundoplication was performed, the frequency of antireflux surgery has increased rapidly with some centers now having an experience of about 1,000 procedures. The question arises whether this increase is due to a change in indications for the surgical treatment of gastrointestinal reflux disease (GERD) despite the simultaneous appearance of powerful antisecretory medications. Adequate knowledge of the pathophysiology of GERD is necessary in order to establish selection criteria for patients suitable for laparoscopic antireflux surgery. In this article, we review the epidemiology and pathophysiology, and provide a rationale for medical and surgical treatment. We also offer an approach to patient selection for antireflux surgery.