Ringer’s solution but not hydroxyethyl starch or modified fluid gelatin enhances platelet microvesicle formation in a porcine model of septic shock{dagger}

T. Schuerholz*,1, R. Sümpelmann1, S. Piepenbrock1, M. Leuwer2 and G. Marx2

1 Department of Anaesthesia, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. 2 University Department of Anaesthesia, University of Liverpool, L69 3GA, UK

*Corresponding author. E-mail: schuerholz.tobias{at}mh-hannover.de

Accepted for publication: December 5, 2003


    Abstract
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Background. Sepsis is associated with volume deficit and clotting system activation. Platelet activation in sepsis results in an increased formation of microvesicles, which in turn, have been associated with increased mortality. We hypothesized an effect of different volume replacement solutions on platelet-derived microvesicle formation in septic shock.

Methods. Anaesthetized, mechanically ventilated and multi-catheterized pigs received 1 g kg–1 body weight faeces into the abdominal cavity to induce sepsis and were observed over 8 h. Five animals in each group received volume replacement therapy with modified fluid gelatin 4% or 8% (MFG4%, MFG8%), 6% hydroxyethylstarch (HES) 200/0.5 or Ringer’s solution (RS) to maintain a central venous pressure of 12 mm Hg. Flow cytometry was used for determination of microvesicles before induction of sepsis (baseline) and after 8 h. Platelets and microvesicles were identified with an anti-platelet monoclonal Ab and a secondary antibody. Microvesicles were determined as the smallest 1–3% positive cells in forward scatter. Intergroup comparisons were performed using Wilks–Lambda and Ryan–Einot–Gabriel–Welsh F-test. Differences within groups were compared using a two-tailed Student’s t-test.

Results. Baseline values were considered as 100%. While microvesicle formation was reduced in HES (73 (SD 19)%), MFG4% (63 (41)%) and MFG8% groups (53 (17)%), an increase in the RS-group (210 (121)%) was observed. Eight hours after induction of sepsis, formation of microvesicles was significantly higher in the RS group compared to all colloid-treated groups.

Conclusion. In this porcine septic shock model the formation of platelet-derived microvesicles was significantly increased by volume replacement with Ringer’s solution in comparison to colloid solutions.

Br J Anaesth 2004; 92: 716–21

Keywords: blood, plasma substitutes; blood, platelets; complications, sepsis; complications, septic shock; microvesicles


    Introduction
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Despite recent progress in understanding of the pathophysiology of sepsis and improvements in supportive intensive care, the incidence of sepsis and the number of sepsis-related deaths is increasing.1 An epidemiological survey estimated that there are 751 000 severe sepsis cases per year in the US with a mortality of 28.6%.2 A variety of mediators and inflammatory cascade reactions that occur in sepsis induce activation of platelets. Activated platelets, in turn, form microvesicles by shedding of membranes from the cell surface.3 These microvesicles have been shown to have anticoagulant as well as procoagulant properties.4 In particular, it has been demonstrated that they are able to reduce bleeding time in a model of thrombocytopenia5 and to shorten the activated partial thromboplastin time (aPTT).6

Larson and colleagues7 have described the induction of platelet microvesicle formation in gram-negative induced human septic shock and experimental endotoxaemia. Increased microvesicle formation has been associated with a higher mortality in a porcine model of endotoxaemia,8 and has been related to fatal outcome in patients with activated coagulation.9

Our study is based on the assumption that the choice of volume replacement therapy may also have an important impact on the coagulation process, as it has been recently demonstrated that the use of crystalloids resulted in an enhancement of coagulation.10 This might be particularly important in patients with severe sepsis/septic shock who generally present with large fluid deficits and therefore need volume replacement therapy.11 Although it is widely accepted that volume replacement therapy is important for restoration and maintenance of the intravascular volume in order to improve organ perfusion and nutritive microcirculatory flow, the type of solution which should be used in the treatment of sepsis remains controversial.12

Given the lack of data in respect to the effect of different volume replacement solutions on microvesicle formation during sepsis the aim of our study was to investigate the effects of 4 and 8% modified fluid gelatin, hydroxyethyl starch with a mean molecular weight (MW) of 200 kD and a substitution ratio of 0.5 and Ringer’s solution on platelet-derived microvesicle formation in a porcine septic shock model.


    Methods
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Animals
German landrace pigs (n=20) of either gender, mean weight 20.8 (SD 1.8) kg, were used. The study protocol was approved by the University Animal Care Committee as well as the federal authorities for animal research of the Bezirksregierung Hannover, Niedersachsen, Germany and the principles of laboratory animal care were followed. The experiments were performed at the animal laboratory of Hannover Medical School (Germany). Animals were fasted for 24 h with access to water ad libitum.

Anaesthesia
As previously described,13 animals received a premedication of of Azaperon 5 mg kg–1 (Stressnyl®, Jansen, Neuss, Germany) intramuscularly. Thereafter a peripheral venous catheter was placed in an ear vein and anaesthesia was induced by intravenous injection of propofol (Disoprivan®, Zeneca, Plankstadt, Germany) until intubating conditions were achieved. Pigs were orally intubated and placed in the supine position. Anaesthesia was maintained with infusion of thiopentone 5 mg kg–1 h–1 (Trapanal®, Byk Gulden, Konstanz, Germany), and fentanyl 0.01 mg kg–1 h–1 (Fentanyl Curamed®, Curamed, Karlsruhe, Germany). Controlled mode ventilation was chosen to ventilate the animals (Servo 900, Siemens-Elema, Solna, Sweden) with an inspiratory oxygen fraction of 0.4, an inspiratory/expiratory ratio of 1:2, and a respiratory rate of 16 bpm. The tidal volume was adjusted to maintain a PCO2 of 35 to 45 torr (4.6 to 5.9 kPa). The core body temperature was maintained at 37–39°C using an infrared lamp, a circulating water-mattress and warmed solutions.

Surgical procedures
Right jugular vein and right carotid artery, as well as the left femoral artery were surgically exposed. For drug and fluid administration a central venous catheter was inserted into the superior vena cava, and a balloon-tipped thermodilution pulmonary artery catheter (131F7, Baxter Healthcare, Irvine, CA, USA) was inserted via the right jugular vein. Catheters and infusion systems were not lined with heparin.

In all animals a midline laparotomy and cystotomy were performed using standardized sterile surgical techniques. A urinary catheter was placed to drain and determine urine output. An opening of 2 cm was made in the caecum and 1 g kg–1 body weight of its content was aspirated. The caecotomy was then closed and a sterile catheter positioned intra-abdominally before the abdomen was closed with a suture. The catheter was tunnelled out through the subcutaneous tissue of the lateral flank. Following surgical preparation animals were allowed to recover for 120 min before baseline measurements (baseline) were performed. A continuous infusion of Ringer’s solution (RS; 10 ml kg–1 h–1 i.v.) was given during surgery and the postsurgical period. To induce sepsis, autologous faeces (1 g kg–1) suspended in 150 ml of warm isotonic NaCl (37°C) was injected through the abdominal catheter.

Monitoring and laboratory measurements
Mean arterial pressure (MAP), central venous pressure (CVP) and pulmonary arterial occlusion pressure (PAOP) were recorded from calibrated pressure transducers (Peter v. Berg, Medizintechnik, Engelharting, Germany). Cardiac output (CO) was determined by thermodilution with a CO computer (Vigilance®; Baxter Healthcare, Irvine, CA, USA). Data reported being the mean of three injections of 5 ml ice-cold 5% glucose randomly spread over the respiratory cycle. Arterial and mixed venous blood was sampled in heparinized syringes and immediately analyzed (System 860 including co-oximetry system 835, Bayer Diagnostics, Fernwald, Germany) to determine blood gases, pH, PCO2, PO2, and the calculated variables base excess, standard bicarbonate, and oxygen saturation. This also allowed calculation of systemic oxygen delivery (DO2) and oxygen consumption (VO2) from haemoglobin, oxygen saturation, PO2 and CO according to standard formulae.

Haematocrit (Hct) and platelet count were determined using an automatic cell counter. Cumulative fluid balance was calculated as fluid input minus urinary output over the observation period (8 h).

Experimental procedure
According to a predefined random list, five animals in each group were allocated for fluid therapy with 4% modified fluid gelatin (MFG4%) (Gelafundin, B Braun, Melsungen, Germany) or 8% modified fluid gelatin (MFG8%) (Braun Medical AG, St Gallen, Switzerland), 6% hydroxyethyl starch (HES) (MW 200 kD/0.5 degree of substitution, Hemohes, B Braun, Melsungen, Germany), and Ringer’s solution (DAB 7, B Braun, Melsungen, Germany). The pH of the Ringer’s solution used varies between 5.0 and 7.0 (manufacturer’s information). In our study we did not check individual bag pH values. Haemodynamic treatment scheme was aimed at maintenance of CVP of 12 mm Hg. After induction of sepsis, animals were observed for 8 h. All variables and blood samples were measured simultaneously before induction of sepsis (baseline) and 8 h after induction. Blood samples for determination of microvesicles were collected in 1.4 ml sodium citrate tubes (No. 06.1668.001, Sarstedt, Nuembrecht, Germany).

Measurement of plasma volume and albumin escape rate
For measurement of the red blood cell volume (RBV) 10 ml of blood was withdrawn and erythrocytes in the plasma-free suspension were labelled with chromium-51-tagged erythrocytes (51Cr) (Berthold MAG 312, Germany). After central venous reinjection of the labelled erythrocytes, arterial blood samples (2 ml) were taken after 30, 45, 240 and 480 min. RBV was calculated from the radioactivity of the isotope before injection and after distribution in the blood: RBV=Total 51Cr activity injectedxHaematocrit (Hct)xf/Blood 51Cr activity of the samplex100. Concentration with f=correction factor (0.91) for whole body Hct. Plasma volume (PV) was determined using a standard formula: PV=(100–Hct)xfxRBV/Hctxf.

Preparation of samples for flow cytometry
Platelet-rich plasma (5 µl) was added to polystyrene tubes containing 30 µl HEPES-diluted anti-platelet antibody (mouse-anti-pig, DH Sachs, Charlestown, PA, USA). The samples were incubated for 20 min at room temperature. After washing with HEPES-buffer the second fluorescent antibody (goat-anti-mouse-Phycoerythrin, DAKO, Denmark) was added and incubated for 15 min at room temperature. Again the samples were washed with HEPES and then diluted and fixed with 500 µl ice-cold PBS, containing 1% p-formaldehyde. Flow cytometry-analysis was performed within 1 h of sampling.

Flow cytometry
Porcine platelets were analyzed using an Epics XL® cytometer (Beckman Coulter, Krefeld, Germany). Data processing from 20 000 platelets was carried out using WinMDI software.14 The cytometer gives information related to mean cell size (forward scatter), complexity (side scatter) and percentage of positive antibody-stained cells based on their light-scattering properties. Each single cell is represented by a point in a coordinate system. Analytical markers were set in the fluorescence channel to divide a negative control sample into fractions containing 97–99% of platelets and 1–3% of the smallest platelets. Platelets with forward scatter lower than the marker were identified as microvesicles. All measurements were run in duplicate. Microvesicles were counted as a percentage of the platelets smaller than a predetermined size in forward scatter in flow cytometry.7

Statistical analysis
Data were analysed using SPSS for Windows (release 10.07) and all results are presented as mean (SD). After verifying normal distribution (skewness <1.5),15 first a multivariate analysis of variance for repeated measurements using Wilks–Lambda16 was performed, followed by a multiple test strategy of Ryan–Einot–Gabriel–Welsh F-test17 for pairwise intergroup comparison. Differences within groups were compared by two-tailed Student’s t-test for paired samples. In order to test the formation of microvesicles and platelets, count baseline values were set as 100% and differences to baseline were calculated.

A P-value <0.05 was considered statistically significant. For this significance level of {alpha}=0.05 an analysis for the prospective power of the experimental design was performed for a 2-sided test. A 50% difference in means of the microvesicle formation between two groups was regarded as clinically important. To achieve a power level of 90% five animals in each group were needed.


    Results
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
Systemic haemodynamic parameters following the induction of sepsis are summarized in Table 1. Baseline values were comparable in all groups. During sepsis there was a significant decrease in MAP and CO in all groups. Eight hours after induction of sepsis, CO was higher in the HES-treated group when compared with MFG4%, MFG8% and RS groups (Table 1). To maintain a CVP of 12 mm Hg, cumulative fluid balance in the RS group was significantly higher compared to HES and MFG4% and MFG8% (Table 2). Compared to baseline, PV was significantly reduced in the RS group. PV could be maintained by HES, MFG4% and MFG8% (Table 2). Compared to baseline the platelet count was significantly reduced in HES group with no differences between the groups 8 h after induction of sepsis (Fig. 1). Compared to baseline, microvesicle formation in the MFG8% group was significantly reduced 8 h after induction of sepsis (Fig. 2). The formation of microvesicles was significantly increased 8 h after induction of sepsis in the RS group when compared to MFG4%, MFG8% and HES treated animals (Fig. 2).


View this table:
[in this window]
[in a new window]
 
Table 1 Haemodynamic parameters. There were five animals in each group; data are presented as mean (SD). HR=heart rate; MAP=mean arterial pressure; CVP=central venous pressure; PAOP=pulmonary artery occlusion pressure; CO=cardiac output; RS=Ringer’s solution; HES=hydroxyethyl starch; MFG4%=modified fluid gelatin 4%; MFG8%=modified fluid gelatin 8%. *P<0.05 RS vs HES, MFG4%, MFG8%; **P<0.05 HES vs MFG4%, MFG8%, RS; #P<0.05 vs baseline
 

View this table:
[in this window]
[in a new window]
 
Table 2 Laboratory parameters. There were five animals in each group; data are presented as mean (SD). (PV=plasma volume; pHa=arterial pH; DO2=systemic oxygen delivery; VO2=systemic oxygen consumption; RS=Ringer’s solution; HES=hydroxyethyl starch; MFG4%=modified fluid gelatin 4%; MFG8%=modified fluid gelatin 8%). *P<0.05 RS vs HES, MFG4%, MFG8%; **P<0.05 HES vs RS, MFG4%, MFG8%; #P<0.05 vs baseline
 


View larger version (16K):
[in this window]
[in a new window]
 
Fig 1 Percent change in platelet count 8 h following induction of sepsis compared to baseline. There were five animals in each group; data are presented as percent for each animal. (RS, Ringer’s solution; HES, hydroxyethyl starch; MFG4%, modified fluid gelatin 4%; MFG8% modified fluid gelatin 8%.) #P<0.05 vs baseline.

 


View larger version (17K):
[in this window]
[in a new window]
 
Fig 2 Percent change in microvesicle formation at 8 h following induction of sepsis compared to baseline. There were five animals in each group; data are presented as percent for each animal. (RS, Ringer’s solution; HES, hydroxyethyl starch; MFG4%, modified fluid gelatin 4%; MFG8%, modified fluid gelatin 8%.) *P<0.05 RS vs HES, MFG4%, MFG8%; #P<0.05, vs baseline.

 

    Discussion
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
The most important finding of our study was a significant increase in the formation of platelet-derived microvesicles in animals treated with Ringer’s solution compared to treatment with artificial colloids HES, MFG4% and MFG 8% in a porcine model of septic shock.

Compared to baseline there was a reduction in the platelet count in RS, MFG8%, HES group, which was significant in the latter. The increase in the MFG4% group is due to one animal, which had a very low baseline platelet count, which increased to sub-normal values at the end of the study period. In our study the platelet count did not differ between the groups 8 h after induction of sepsis. Thus, our results confirm the findings of Larsson and colleagues who support the view that microvesicle formation is not a simple reflection of a decrease in platelet count.7

Similar to our results, increased formation of platelet-derived microvesicles has been reported in human gram-negative septic shock and experimental porcine sepsis. During clinical sepsis the activation of platelets and the coagulation system is well known.18 Recently, it has been suggested that activation of platelets and monocytes as well as adhesion of platelets to neutrophils may play a role in the development of organ dysfunction.19

In our model, we observed that the massive fluid input in the Ringer’s solution group comprising a total fluid volume of 11.5 (3.6) litre (576 (183) ml kg–1), and a positive fluid balance after 8 h of 7.3 (1.0) litre (366 (49) ml kg–1) was associated with a reduced plasma volume. In contrast, restoration of adequate intravascular volume was obtained in the colloid groups. This was combined with a metabolic acidosis and significant lower VO2 in the RS group compared to the colloid groups. This may indicate circulatory alterations and sequestration occurring in the RS group, thereby reducing functional capacity of vital organs and contributing further to an activation of the coagulation cascade. RS may increase tissue oedema compared to the colloids used. One effect of such an oedema would be to retard oxygen uptake by increasing the distance from blood vessels to the mitochondria; this in turn could reduce functional capacity and contribute to the development of coagulopathy and multiple organ failure.20 The composition of the different solutions may also be important. Recently, it has been shown that a crystalloid solution in which lactate was substituted by ethyl pyruvate ameliorated intestinal hyperpermeability in rats.21 Pyruvate probably serves as an endogenous scavenger of ROS, which have been implicated in the pathogenesis of coagulopathy and sepsis. In a murine model of lethal endotoxaemia, treatment with a Ringer’s ethyl pyruvate solution in place of a Ringer’s lactated solution prolonged survival and blunted the release of interleukin-6.22 According to our results, Ruttmann and colleagues23 could demonstrate enhanced coagulation measured by TEG with a volume load of about 1000 ml h–1 for 3 h.

The underlying reasons for the enhanced activation of platelets using crystalloid Ringer’s solution remains speculative. It has been discussed that a direct endotoxin effect may cause the increased formation of platelet-derived microvesicles.7 Another explanation is that the release of platelet-derived microvesicles could be mediated by complement activation.24 Furthermore, platelet-derived microparticles formed during complement activation in vivo could provide a membrane surface that facilitates the assembly and dissemination of procoagulant enzyme complexes. In this respect, platelet-derived microvesicles might have a potential role in the pathogenesis of disseminated intravascular coagulation.24 Interestingly, we demonstrated previously, that the complement system is activated in our porcine septic shock model.25

Another interesting aspect may be the influence of crystalloids on coagulation. In vitro haemodilution with saline26 or other crystalloid solutions27 exerted a procoagulant effect, possibly by enhancement of thrombin formation. Recent clinical work demonstrated that haemodilution of up to 30% with saline can induce a hypercoagulable state.10 This increase in coagulation seems to be independent of the type of crystalloid used.28 The reduction in antithrombin caused by dilution has been postulated as a possible important mechanism for the enhancement of haemodilution-induced coagulation.29 In contrast, Innerhofer and colleagues, investigating primary platelet-mediated haemostasis and clot formation, demonstrated that perioperative administration of 6% HES 200/0.5 or MFG4% interfered more with fibrin polymerization and resulting total clot strength than did RS.30

There may be clinical implications in measuring the production of microvesicles: in order to elucidate the effects of different fluid types, appropriate study endpoints need to be developed, as mortality does not seem to be a useful endpoint for fluid resuscitation. Since activation of coagulation occurs in septic shock, measuring the formation of platelet-derived microvesicles might possibly be used as a guide towards therapy.

In conclusion, in a porcine model of septic shock we have shown that the formation of platelet-derived microvesicles was significantly increased in animals treated with Ringer’s solution, but not in animals treated with artificial colloids HES, MFG4% and MFG 8%. These results suggest that the intravascular activation of platelets in experimental sepsis may be enhanced by crystalloids.


    Acknowledgement
 
We thank Professor H. Hecker for his statistical advice.


    References
 Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
1 Martin GS, Mannino DM, Eaton S, Moss M. The Epidemiology of Sepsis in the United States from 1979 through 2000. N Engl J Med 2003; 348: 1546–54[Abstract/Free Full Text]

2 Angus DC, Linde-Zwirble WT, Lidicker J, Clermont G, Carcillo J, Pinsky MR. Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med 2001; 29: 1303–10[ISI][Medline]

3 Heijnen HFG, Schiel AE, Fijnheer R, Geuze HJ, Sixma JJ. Activated platelets release two types of membrane vesicles: microvesicles by surface shedding and exosomes derived from exocytosis of multivesicular bodies and alpha-granules. Blood 1999; 94: 3791–9[Abstract/Free Full Text]

4 Tans G, Rosing J, Thomassen MC, Heeb MJ, Zwaal RF, Griffin JH. Comparison of anticoagulant and procoagulant activities of stimulated platelets and platelet-derived microparticles. Blood 1991; 77: 2641[Abstract]

5 McGill M, Fugman DA, Vittorio N, Darrow C. Platelet membrane microvesicles reduced microvascular bleeding times in thrombocytopenic rabbits. J Lab Clin Med 1987; 109: 127–33[ISI][Medline]

6 Howard MA, Coghlan M, David R, Pfueller SL. Coagulation activities of plasma microparticles. Thromb Res 1988; 50: 145–56[CrossRef][ISI][Medline]

7 Larsson A, Lundahl T, Eriksson M, Lundkvist K, Lindahl T. Endotoxin induced platelet microvesicle formation measured by flow cytometry. Platelets 1996; 7: 153–8[ISI]

8 Eriksson M, Nelson D, Nordgren A, Larsson A. Increased platelet microvesicle formation is associated with mortality in a porcine model of endotoxemia. Acta Anaesthesiol Scand 1998; 42: 551–7[ISI][Medline]

9 Holme PA, Solum NO, Brosstad F, Roger M, Abdelnoor M. Demonstration of platelet-derived microvesicles in blood from patients with activated coagulation and fibrinolysis using a filtration technique and western blotting. Thromb Haemost 1994; 72: 666–71[ISI][Medline]

10 Ng KFJ, Lam CCK, Chan LC. In vivo effect of haemodilution with saline on coagulation: a randomized controlled trial. Br J Anaesth 2002; 88: 475–80[Abstract/Free Full Text]

11 Imm A, Carlson RW. Fluid resuscitation in circulatory shock. Crit Care Clin 1993; 9: 313–33[ISI][Medline]

12 Marx G. Fluid therapy in sepsis with capillary leakage. Eur J Anaesthesiol 2003; 20: 429–42[ISI][Medline]

13 Marx G, Cobas Meyer M, Schuerholz T, Vangerow B, Gratz KF, Hecker H, Sümpelmann R, Rueckoldt H, Leuwer M. Hydroxyethyl starch and modified fluid gelatin maintain plasma volume in a porcine model of septic shock with capillary leakage. Intensive Care Med 2002; 28: 629–35[CrossRef][ISI][Medline]

14 Trotter J. WinMDI 28. Scripps Research Institute, La Jolla, CA, USA

15 Pearson ES. Please NW Relation between the shape of population distribution and the robustness of four simple test statistics. Biometrika 1975; 62: 223–41[ISI]

16 Rencher AC. The contribution of individual variables to Hotelling’s T2, Wilk’s lambda and R2. Biometrics 1993; 49: 479–89[ISI][Medline]

17 Einot I, Gabriel KR. A study of the powers of several methods of multiple comparisons. J Am Stat Assoc 1975; 70: 574–83[ISI]

18 Mavrommatis AC, Theodoridis T, Orfanidou A, Roussos C, Christopoulou-Kokkinou V, Zakynthinos S. Coagulation system and platelets are fully activated in uncomplicated sepsis. Crit Care Med 2000; 28: 451–57[ISI][Medline]

19 Russwurm S, Vickers J, Meier-Hellmann A, Spangenberg P, Bredle P, Reinhart K, Lösche W. Platelet and leukocyte activation correlate with the severity of septic organ dysfunction. Shock 2002; 17: 263–8[CrossRef][ISI][Medline]

20 Groeneveld AB. Albumin and artificial colloids in fluid management: where does the clinical evidence of their utility stand? Crit Care 2000; 4: S16–20[ISI][Medline]

21 Tawadrous ZS, Delude RL, Fink MP. Resuscitation from hemorrhagic shock with Ringer’s ethyl pyruvate solution improves survival and ameliorates intestinal mucosal hyperpermeability in rats. Shock 2002; 17: 473–7[CrossRef][ISI][Medline]

22 Venkataraman R, Kellum JA, Song M, Fink MP. Resuscitation with Ringer’s ethyl pyruvate solution prolongs survival and modulates plasma cytokine and nitrite/nitrate concentrations in a rat model of lipopolysaccharide-induced shock. Shock 2002; 18: 507–12[CrossRef][ISI][Medline]

23 Ruttmann TG, James MFM, Finlayson J. Effects on coagulation of intravenous crystalloid or colloid in patients undergoing peripheral vascular surgery. Br J Anaesth 2002; 89: 226–30[Abstract/Free Full Text]

24 Sims PJ, Faioni EM, Wiedmer T, Shattil SJ. Complement proteins C5b-9 cause release of membrane vesicles from the platelet surface that are enriched in the membrane receptor for coagulation factor Va and express prothrombin activity. J Biol Chem 1988; 263: 18205–12[Abstract/Free Full Text]

25 Marx G, Cobas Meyer, M Schuerholz T, Vangerow B, Gratz KF, Hecker H, Sümpelmann R, Rueckoldt H, Leuwer M. Terminal complement complex in porcine septic shock with capillary leak syndrome. Br J Anaesth 2001; 87: 172–3P

26 Ruttmann TG, James MFM, Viljoen JF. Haemodilution induces a hypercoagulable state. Br J Anaesth 1996; 76: 412–14[Abstract/Free Full Text]

27 Ruttmann TG, James MF, Wells KF. Effect of 20% in vitro haemodilution with warmed buffered salt solution and cerebrospinal fluid on coagulation. Br J Anaesth 1999; 82: 110–11[Abstract/Free Full Text]

28 Boldt J, Haisch Gm, Suttner S, Kumle B, Schellhase F. Are lactated Ringer’s solution and normal saline solution equal with regard to coagulation? Anesth Analg 2002; 94: 378–84[Abstract/Free Full Text]

29 Ruttmann TG, James MFM, Aronson I. In vivo investigation into the effects of haemodilution with hydroxyethyl starch (200/05) and normal saline on coagulation. Br J Anaesth 1998; 80: 612–16[CrossRef][ISI][Medline]

30 Innerhofer P, Fries D, Margreiter J, Klingler A, Kuhbacher G, Wachter B, Oswald E, Salner E, Frischhut B, Schobersberger W. The effects of perioperatively administered colloids and crystalloids on primary platelet-mediated hemostasis and clot formation. Anesth Analg 2002; 95: 858–65[Abstract/Free Full Text]





This Article
Abstract
Full Text (PDF)
All Versions of this Article:
92/5/716    most recent
aeh127v1
E-Letters: Submit a response to the article
Alert me when this article is cited
Alert me when E-letters are posted
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in ISI Web of Science
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Search for citing articles in:
ISI Web of Science (1)
Disclaimer
Request Permissions
Google Scholar
Articles by Schuerholz, T.
Articles by Marx, G.
PubMed
PubMed Citation
Articles by Schuerholz, T.
Articles by Marx, G.