severe sepsis and septic shock are common causes of mortality and morbidity in an intensive care unit ( icu ) setting .
the endotoxin ( lipopolysaccharide [ lps ] ) derived from the outer membranes of gram - negative bacteria is considered a major factor in the pathogenesis of sepsis .
the toll - like receptor ( tlr ) family can be found in mammalian cells .
endotoxins transduce their signal through the tlr4 transmembrane receptor , and innate immune cascades are initiated , which promote excessive cytokine release and tissue damage .
the endotoxin level is associated with clinical outcome and higher activity correlates with greater icu mortality .
therapeutic strategies aimed at minimizing or preventing the action of endotoxins are , therefore , attractive .
however , the blockage of an endotoxin via binding with monoclonal antibodies has failed to improve outcome in clinical studies .
the reduction of endotoxin levels or blockage of endotoxins can potentially interrupt the biological cascade of sepsis .
polymyxin b ( pmx ) is an antibiotic agent that has strong gram - negative bactericidal activity and carries very high affinity for endotoxins .
intravenous ( iv ) administration of pmx has significant nephrotoxicity and neurotoxicity , which has limited its clinical use .
pmx can be immobilized covalently on polystyrene - based carrier fibers which preserve its endotoxin binding capacity without producing toxicity .
a pmx immobilized fiber column was shown to improve blood pressure , oxygenation and mortality in patients with severe sepsis .
the alteco endotoxin hemoadsorber ( alteco medical ab , lund , sweden ) is a similar device with strong endotoxin - binding capacity . during the treatment ,
we performed this randomized controlled trial ( rct ) in patients who suffered from septic shock due to intra - abdominal sepsis .
we hypothesized that alteco endotoxin hemoadsorption may provide extraclinical benefit in terms of faster organ function improvement and hemodynamic stabilization when compared with conventional treatment .
this prospective rct was approved by the institution 's ethics committee and registered with australian new zealand clinical trials registry ( anzctr , actrn12610000892011 ) .
the study was conducted in the adult icu of pamela youde nethersole eastern hospital , which is a 2300-bed acute care tertiary hospital that provides comprehensive care , except for cardiothoracic surgery , transplant surgery , and burns .
the icu is a 22-bed closed mixed medical - surgical unit with an average admission of 1400 patients / year .
we enrolled patients who fulfilled the following inclusion criteria : ( 1 ) age 18 and 85 years old ; ( 2 ) presence of severe sepsis due to intra - abdominal infection where severe sepsis was defined using the american college of chest physicians / society of critical care medicine / european society of intensive care medicine criteria ; ( 3 ) presence of shock with mean arterial pressure ( map ) 65 mmhg ; ( 4 ) requirement of vasopressor support ( noradrenaline 0.2 g / kg / min or equivalent ) ; and ( 5 ) on hydrocortisone 200 - 300 mg iv / day or equivalent to cover potential relative adrenal insufficiency .
exclusion criteria of the study were : pregnancy , terminally ill patients with life expectancy 3 months , hypersensitivity to heparin or low molecular heparin or any component of the formulation , known history of heparin - induced thrombocytopenia ; severe thrombocytopenia ( < 50,000/mm ) , uncontrolled active bleeding except when due to disseminated intravascular coagulation , and inclusion in other icu studies .
informed consent was obtained from patients directly . for those with impaired consciousness due to underlying illness or the use of sedatives
block randomization was performed using a computer generated scheme , and the allocation sequence was concealed in sealed envelopes which were available 24 h a day in the icu .
the control group ( cg ) received conventional therapy for septic shock , namely : infective sources control , early appropriate antibiotics , fluid challenge and vasopressor infusion , and lung protected ventilatory strategy based on surviving sepsis campaign guidelines .
continuous renal replacement therapy ( crrt ) in the form of citrate - based postdilution continuous venovenous hemofiltration using polysulfone high flux hemofilter ( f  80 , fresenius medical care , germany ) was provided in the presence of acute kidney injury categorized as  injury  or more based on risk , injury , failure , loss , and end - stage ( rifle ) criteria .
treatment group ( tg ) ( endotoxin hemoadsorption group ) received endotoxin hemoadsorption in addition to conventional therapy . a double lumen 12-f hemodialysis catheter ( arrowguard blue plus antimicrobial catheter , arrow international inc . , usa )
was inserted into either the internal jugular or femoral vein for vascular access by the attending intensivists / physicians immediately after randomization .
endotoxin hemoadsorption was performed with alteco endotoxin hemoadsorber using ak10 machine ( gambro - hospal , stockholm , sweden ) at a blood flow rate of 120 - 150 ml / h . each patient received two 2-hourly sessions of hemoadsorption 24 h apart .
low molecular weight heparin ( lmwh ) was used for anticoagulation at the discretion of the treating physician , with tinzaparin 1000 iu iv as the default dosage .
crrt was started in - between two sessions of hemoadsorption and afterwards based on the same starting criteria for cg if necessary .
disease severity and prognosis were assessed with acute physiology and chronic health evaluation ( apache ) iv score .
clinical parameters and laboratory data were recorded at 0 , 24 , 48 , and 72 h of randomization .
dosage of vasopressor was expressed as vasopressor score ( vs ) using the formula : ( dopamine dose  1 ) + ( dobutamine dose  1 ) + ( adrenaline dose  100 ) + ( noradrenaline dose  100 ) + ( phenylephrine dose  100 ) , wherein all doses are expressed as g / kg / min .
dose - response relationship between vasopressor and blood pressure was expressed as vasopressor dependency index ( vdi ) and was calculated using the formula : vs / map .
primary end point was the change of the sofa score from 0 to 72 h of randomization .
secondary end points included changes of vs , vdi , pao2/fio2 ratio , icu length of stay ( los ) , hospital los , and 28-day mortality .
sample size was estimated based on previous study findings . with the power of 80% ,
type i error probability of 0.05 , mean sofa score difference of 2 , standard deviation of 1.5 , the estimated sample size was 20 .
univariate analysis was performed using fisher 's exact test for categorical data or mann - whitney u - test for continuous data where appropriate .
the analysis was performed by the statistical package for social sciences for windows , version 16.0 ( spss , chicago , il , united states ) .
this prospective rct was approved by the institution 's ethics committee and registered with australian new zealand clinical trials registry ( anzctr , actrn12610000892011 ) .
the study was conducted in the adult icu of pamela youde nethersole eastern hospital , which is a 2300-bed acute care tertiary hospital that provides comprehensive care , except for cardiothoracic surgery , transplant surgery , and burns .
the icu is a 22-bed closed mixed medical - surgical unit with an average admission of 1400 patients / year .
we enrolled patients who fulfilled the following inclusion criteria : ( 1 ) age 18 and 85 years old ; ( 2 ) presence of severe sepsis due to intra - abdominal infection where severe sepsis was defined using the american college of chest physicians / society of critical care medicine / european society of intensive care medicine criteria ; ( 3 ) presence of shock with mean arterial pressure ( map ) 65 mmhg ; ( 4 ) requirement of vasopressor support ( noradrenaline 0.2 g / kg / min or equivalent ) ; and ( 5 ) on hydrocortisone 200 - 300 mg iv / day or equivalent to cover potential relative adrenal insufficiency .
exclusion criteria of the study were : pregnancy , terminally ill patients with life expectancy 3 months , hypersensitivity to heparin or low molecular heparin or any component of the formulation , known history of heparin - induced thrombocytopenia ; severe thrombocytopenia ( < 50,000/mm ) , uncontrolled active bleeding except when due to disseminated intravascular coagulation , and inclusion in other icu studies .
informed consent was obtained from patients directly . for those with impaired consciousness due to underlying illness or the use of sedatives
block randomization was performed using a computer generated scheme , and the allocation sequence was concealed in sealed envelopes which were available 24 h a day in the icu .
the control group ( cg ) received conventional therapy for septic shock , namely : infective sources control , early appropriate antibiotics , fluid challenge and vasopressor infusion , and lung protected ventilatory strategy based on surviving sepsis campaign guidelines .
continuous renal replacement therapy ( crrt ) in the form of citrate - based postdilution continuous venovenous hemofiltration using polysulfone high flux hemofilter ( f  80 , fresenius medical care , germany ) was provided in the presence of acute kidney injury categorized as  injury  or more based on risk , injury , failure , loss , and end - stage ( rifle ) criteria .
treatment group ( tg ) ( endotoxin hemoadsorption group ) received endotoxin hemoadsorption in addition to conventional therapy . a double lumen 12-f hemodialysis catheter ( arrowguard blue plus antimicrobial catheter , arrow international inc . , usa )
was inserted into either the internal jugular or femoral vein for vascular access by the attending intensivists / physicians immediately after randomization .
endotoxin hemoadsorption was performed with alteco endotoxin hemoadsorber using ak10 machine ( gambro - hospal , stockholm , sweden ) at a blood flow rate of 120 - 150 ml / h . each patient received two 2-hourly sessions of hemoadsorption 24 h apart .
low molecular weight heparin ( lmwh ) was used for anticoagulation at the discretion of the treating physician , with tinzaparin 1000 iu iv as the default dosage .
crrt was started in - between two sessions of hemoadsorption and afterwards based on the same starting criteria for cg if necessary .
disease severity and prognosis were assessed with acute physiology and chronic health evaluation ( apache ) iv score .
clinical parameters and laboratory data were recorded at 0 , 24 , 48 , and 72 h of randomization .
dosage of vasopressor was expressed as vasopressor score ( vs ) using the formula : ( dopamine dose  1 ) + ( dobutamine dose  1 ) + ( adrenaline dose  100 ) + ( noradrenaline dose  100 ) + ( phenylephrine dose  100 ) , wherein all doses are expressed as g / kg / min .
dose - response relationship between vasopressor and blood pressure was expressed as vasopressor dependency index ( vdi ) and was calculated using the formula : vs / map .
primary end point was the change of the sofa score from 0 to 72 h of randomization .
secondary end points included changes of vs , vdi , pao2/fio2 ratio , icu length of stay ( los ) , hospital los , and 28-day mortality .
sample size was estimated based on previous study findings . with the power of 80% ,
type i error probability of 0.05 , mean sofa score difference of 2 , standard deviation of 1.5 , the estimated sample size was 20 .
univariate analysis was performed using fisher 's exact test for categorical data or mann - whitney u - test for continuous data where appropriate .
the analysis was performed by the statistical package for social sciences for windows , version 16.0 ( spss , chicago , il , united states ) .
this prospective rct was approved by the institution 's ethics committee and registered with australian new zealand clinical trials registry ( anzctr , actrn12610000892011 ) .
the study was conducted in the adult icu of pamela youde nethersole eastern hospital , which is a 2300-bed acute care tertiary hospital that provides comprehensive care , except for cardiothoracic surgery , transplant surgery , and burns .
the icu is a 22-bed closed mixed medical - surgical unit with an average admission of 1400 patients / year .
we enrolled patients who fulfilled the following inclusion criteria : ( 1 ) age 18 and 85 years old ; ( 2 ) presence of severe sepsis due to intra - abdominal infection where severe sepsis was defined using the american college of chest physicians / society of critical care medicine / european society of intensive care medicine criteria ; ( 3 ) presence of shock with mean arterial pressure ( map ) 65 mmhg ; ( 4 ) requirement of vasopressor support ( noradrenaline 0.2 g / kg / min or equivalent ) ; and ( 5 ) on hydrocortisone 200 - 300 mg iv / day or equivalent to cover potential relative adrenal insufficiency .
exclusion criteria of the study were : pregnancy , terminally ill patients with life expectancy 3 months , hypersensitivity to heparin or low molecular heparin or any component of the formulation , known history of heparin - induced thrombocytopenia ; severe thrombocytopenia ( < 50,000/mm ) , uncontrolled active bleeding except when due to disseminated intravascular coagulation , and inclusion in other icu studies .
informed consent was obtained from patients directly . for those with impaired consciousness due to underlying illness or the use of sedatives
block randomization was performed using a computer generated scheme , and the allocation sequence was concealed in sealed envelopes which were available 24 h a day in the icu .
the control group ( cg ) received conventional therapy for septic shock , namely : infective sources control , early appropriate antibiotics , fluid challenge and vasopressor infusion , and lung protected ventilatory strategy based on surviving sepsis campaign guidelines .
continuous renal replacement therapy ( crrt ) in the form of citrate - based postdilution continuous venovenous hemofiltration using polysulfone high flux hemofilter ( f  80 , fresenius medical care , germany ) was provided in the presence of acute kidney injury categorized as  injury  or more based on risk , injury , failure , loss , and end - stage ( rifle ) criteria .
treatment group ( tg ) ( endotoxin hemoadsorption group ) received endotoxin hemoadsorption in addition to conventional therapy . a double lumen 12-f hemodialysis catheter ( arrowguard blue plus antimicrobial catheter , arrow international inc . ,
usa ) was inserted into either the internal jugular or femoral vein for vascular access by the attending intensivists / physicians immediately after randomization .
endotoxin hemoadsorption was performed with alteco endotoxin hemoadsorber using ak10 machine ( gambro - hospal , stockholm , sweden ) at a blood flow rate of 120 - 150 ml / h . each patient received two 2-hourly sessions of hemoadsorption 24 h apart .
low molecular weight heparin ( lmwh ) was used for anticoagulation at the discretion of the treating physician , with tinzaparin 1000 iu iv as the default dosage .
crrt was started in - between two sessions of hemoadsorption and afterwards based on the same starting criteria for cg if necessary .
disease severity and prognosis were assessed with acute physiology and chronic health evaluation ( apache ) iv score . clinical parameters and laboratory data
dosage of vasopressor was expressed as vasopressor score ( vs ) using the formula : ( dopamine dose  1 ) + ( dobutamine dose  1 ) + ( adrenaline dose  100 ) + ( noradrenaline dose  100 ) + ( phenylephrine dose  100 ) , wherein all doses are expressed as g / kg / min .
dose - response relationship between vasopressor and blood pressure was expressed as vasopressor dependency index ( vdi ) and was calculated using the formula : vs / map .
primary end point was the change of the sofa score from 0 to 72 h of randomization .
secondary end points included changes of vs , vdi , pao2/fio2 ratio , icu length of stay ( los ) , hospital los , and 28-day mortality .
sample size was estimated based on previous study findings . with the power of 80% ,
type i error probability of 0.05 , mean sofa score difference of 2 , standard deviation of 1.5 , the estimated sample size was 20 .
univariate analysis was performed using fisher 's exact test for categorical data or mann - whitney u - test for continuous data where appropriate .
the analysis was performed by the statistical package for social sciences for windows , version 16.0 ( spss , chicago , il , united states ) .
this study was terminated early by the monitoring committee as an interim analysis could not identify any significant clinical benefit . from february 2010 to june 2012 , 15 patients were recruited ( seven in the lps hemoadsorption group and eight in the cg ) .
all patients except one from cg yielded gram - negative bacteria from saved microbiological culture specimens . among them , klebsiella species were the most commonly isolated organisms ( total 40% , tg vs. cg = 29% vs. 50% ) , followed by escherichia coli ( total 33% , tg vs. cg = 29% vs. 38% ) .
multiple bacteria were isolated from 27% of cases ( tg vs. cg = 29% vs. 25% ) .
adequate , appropriate initial antibiotic coverage ( based on subsequent microbial sensitivity pattern ) were given to 93% of patients within 24 h of recruitment ( tg vs. cg = 86% vs. 100% ) .
sofa score showed more obvious improvement among cg group at 48 h and 72 h , but this was not statistically significant [ table 2 ] .
both groups showed decreased use of vasopressor over time , but the improvement did not differ between groups .
improvement of oxygenation was more obvious among the tg group but did not reach statistical significance .
continuous veno - venous hemofiltration was given in all tg patients and 63% of cg patients .
for those icu survivors ( six from treatment and control arm respectively ) , no patient required dialysis support within 1 and 3 months after recruitment .
concerning the adverse events during alteco endotoxin hemoadsorption , severe thrombocytopenia ( platelet count < 20  10 /mm ) occurred in one patient but no bleeding event was reported .
transient hypotension ( map 60 mmhg ) occurred in one patient during the initiation of the first endotoxin hemoadsorption , who required increased vasopressor support .
to our best knowledge , the current study is the first rct to investigate the therapeutic effect of this new endotoxin hemoadsorption device ( alteco endotoxin hemoadsorber , alteco medical ab , lund , sweden ) in gram - negative septic shock patients .
unfortunately , the study was terminated early by the monitoring committee as an interim analysis showed a low probability of significant findings .
extracorporeal blood purification as a treatment for sepsis consists of multiple treatment modalities ; these either targeted inflammatory mediators or bacterial toxins like endotoxins or both .
crrt is commonly performed in icu settings for patient with septic acute kidney injury . however , the use of low or normal volume continuous venovenous hemodialysis or hemofiltration failed to demonstrate an improvement of patient outcomes in severe sepsis .
high volume hemofiltration ( hvhf ) or pulse hvhf removed cytokines effectively , and initial study showed promising results .
however , recently published ivoire study could not identify any significant mortality nor organ function benefit when compared with standard volume hemofiltration .
moreover , hvhf incurred an increase of nursing workload ( especially without the use of online treatment modality ) , higher treatment cost due to the use of large volumes of replacement fluid and potential electrolytes / drug concentration disturbances .
hemodialysis or hemodiafiltration using high cutoff membrane offers a good cytokine clearance , but significant albumin loss , together with albumin - bound drugs are the key problem which require particular attention . coupled plasma filtration adsorption is a relatively investigational tool , although initial experiences were impressive .
hemoperfusion with cytokines and/or endotoxin hemoadsorption columns require simple set up and equipment , which is more feasible in an icu setting . nowadays
, there are three different methods for endotoxin hemoadsorption in septic shock which have more clinical experience .
pmx immobilized fiber column hemoperfusion ( toraymyxin , toray industries , tokyo , japan ) is the most commonly used device .
this device has been used for the treatment of septic shock since 1994 in japan and since 2002 in europe .
it has gained popularity worldwide in recent years , especially after the euphas ( early use of pmx b hemoperfusion in abdominal sepsis ) study .
a recent meta - analysis by mitaka clearly showed that pmx hemoperfusion treatment had significant beneficial effects on patient hemodynamics , pulmonary oxygenation , and mortality .
endotoxins may also be bound to an adsorber contained albumin ( matisse , fresenius medical care , bad homburg , germany ) .
trends in the improvement of morbidity and organ dysfunction were found in initial nonrandomized studies .
however , a subsequent multicenter rct could not identify any significant clinical benefit , which then limited its clinical use .
endotoxin capture by specially designed synthetic peptides is another method ( alteco endotoxin hemoadsorber , alteco medical ab , lund , sweden ) .
it is a class iia medical extracorporeal device consisting of a rigid porous matrix which can significantly increase its blood contact area .
tailor - made synthetic peptides with a high affinity for endotoxins are connected to the surface of the polyethylene plates with a covalent bonding technique .
the clinical experience for this device is scarce and is limited to case reports and case series .
showed that the duration of noradrenaline infusion was significantly shorter in adsorber - treated patients compared to controls ( p = 0.03 ) . in our study ,
vasopressor use decreased nicely in adsorber - treated patients but this also occurred in control patients . compared with the study by ala - kokko et al .
, our study cases were older ( 75 vs. 60 years old ) , had more significant organ failure as expressed by sofa score ( 13 vs. 9 ) , were on huge doses of vasopressor ( vs 50.5 vs. 11.1 ) and had much higher predicted mortality ( 65% vs. 27% ) .
these findings also apply when compared with pmx hemoperfusion - treated patients in the euphas study . which indicated that our adsorber - treated cases were much sicker .
by closely examining the difference between the adsorber - treated patients and the controls , we noted that the control cases had faster organ recovery as expressed by a more rapid drop in sofa score , less vasopressor use , better oxygenation improvement , and lower icu length of stay .
although there was no statistically significant difference due to the small sample size , the apache iv score predicted mortality rate was much higher in adsorber - treated patients compared with controls , which may provide a good explanation on the discrepancy in clinical outcome parameters .
it is possible that with such severe cases , the addition of endotoxin hemoadsorption offered no further clinical benefit when compared with standard intensive care , although suboptimal organ support or ineffective endotoxin removal could be other reasons for this .
concerning the first alternative ( suboptimal organ support ) , the standardized mortality ratio by apache iv risk of death for the adsorber - treated patients was 0.7 which was fair ; this indicated that suboptimal care was less likely .
for the second reason , due to great difficulty in sourcing a quantitative endotoxin assay and limited funding , no endotoxin assay was performed .
therefore , we could not be sure that the patients had adequate endotoxin removal during hemoadsorption . concerning the side effects of alteco endotoxin hemoadsorption , ala - kokko et al .
in fact , thrombocytopenia ( platelet count < 150  10 /mm ) occurred in all adsorber - treated patients but only one case suffered from severe thrombocytopenia ( platelet count < 20  10 /mm ) . no bleeding event was noted , and no platelet transfusion was given . in the case
this may be related to the fact that we used lmwh for anticoagulation instead of unfractionated heparin ( ufh ) used in ala - kokko et al .
the pharmacokinetics of lmwh are more predictable than ufh , which may be more obvious in septic patients .
transient hypotension occurred once and required an increase in vasopressor support , but no arrhythmia was documented , as in the cases reported by ala - kokko et al .
the sample size was estimated based on previous studies , but early termination of this study further limited its power . given that there are early reports on the effectiveness of hemoadsorption technique on treatment of septic shock , this negative study could offer readers information on patient 's clinical response and side effect profile of this novel device .
for this single - center study , case recruitment proved to be quite difficult as the endotoxin hemoadsorption technique was a new treatment option in our locality .
recruitment rate was slow and multiple center collaboration could be the only means to resolve this issue .
an endotoxin activity assay ( eaa ) was not performed in our study , similar to the landmark euphas study , due to the unavailability of the point - of - care testing device in our locality .
although endotoxin activity reflects the severity of illness in critically ill septic shock patients , its prognostic value is poor .
we believed that the availability of eaa result should be a bonus but not a must for this study .
however , in order to minimize potential error on cases recruitment , we targeted only those suffering from intra - abdominal sepsis with shock .
so far , the microbiological findings have yielded gram - negative bacteria in almost all of the recruited cases . finally , blinding was not possible for this study and may have contributed to further bias .
we could not identify any clinical benefit on the addition of alteco endotoxin hemoadsorption to conventional therapy in patients who suffered from intra - abdominal sepsis with shock .
the side effect profile of this device was acceptable . given that there are early reports on the effectiveness of hemoadsorption technique on treatment of septic shock , larger multicenter study is indicated to further investigate the potential benefit or drawback of this novel device .
 background and aims : severe sepsis and septic shock are common causes of mortality and morbidity in an intensive care unit setting . 
 endotoxin , derived from the outer membranes of gram - negative bacteria , is considered a major factor in the pathogenesis of sepsis . 
 this study investigated the effect of alteco endotoxin hemoadsorption device on gram - negative septic shock patients.materials and methods : an open , controlled , prospective , randomized , single - center trial was conducted between february 2010 and june 2012 . 
 patients with septic shock due to intra - abdominal sepsis were randomized to either conventional therapy ( n = 8) or conventional therapy plus two 2-hourly sessions of alteco endotoxin hemoadsorption ( n = 7 ) . 
 primary endpoint was the sequential organ failure assessment ( sofa ) score changes from 0 to 72 h. secondary end points included vasopressor requirement , pao2/fio2 ratio ( pfr ) , length of stay ( los ) , and 28-day mortality.results:this study was terminated early as interim analysis showed a low probability of significant findings . 
 no significant difference was noted between the two groups with respect to change in sofa score , vasopressor score , pfr , los , and 28-day mortality . 
 side - effect was minimal.conclusions:we could not identify any clinical benefit on the addition of alteco endotoxin hemoadsorption to conventional therapy in patients who suffered from intra - abdominal sepsis with shock . 
 the side effect profile of this novel device was acceptable . 
Introduction
Materials and Methods
None
Patients
Randomization and interventions
Follow-up and data collection
Statistical analysis
Results
Discussion
Conclusion