Continuous renal replacement therapies can either combine convection and diffusion (CVVHDF) or preponderate one over the other (CVVH or CVVHD). Besides, there are other non continuous (24h) options such as SLED that can also be used.
Dont you think that SLED for 4 - 8 hours in a septic shock condition would be a little bit short in terms of fluid management and electrolitic balance?
I agree with Sonali Vadi, Xosé Pérez and Stephen Lapinsky. Our practice is to use SLED.
As in my department we´re not very familiar with SLED we basically use CRRT. However, i would like to ask again SLED experts if we´re talking of 24 h SLED or 6-8 hours extended dialysis? Remember majority of our ICU patients requiring RRT are under unstable hemodynamic condition.
This 4-6 h schedule doesn´t seem to fit in our septic shock patients who present an anuric AKI with high fluid entries specially in the first 24-48 h of resuscitation. Do you really handle this patients with 4-6 h SLED?
Would anyone use continuous hemodialysis (CVVHD) in this type of patient? We sometimes find it quite useful in order to increase filter life (in fact the overall cost would be similar to SLED).
So, keeping on with our septic shock patient, how many of you would use citrate anticoagulation supposing our patient has multiorgan dysfunction (billirrubine 50 ukat/L; PT 1.8).
We still use heparin as anticoagulation system (although nearly 50% of our septic shock patients receive no anticoagulation due to DIC or low platelets). However, we´re trying to start some patients on citrate. Is nice to hear your experience in the field as this encourages us to change our practice in order to improve. Thanks again.
With the patients with DIC, as you recently stated, we would use no anticoagulants. For those patients with essentially normal clotting's yet low platelets, we would use epoprostenol to try and conserve the filter. With this, there is the myocardial effects at high rate. It has been noted that some patients with abnormal clotting's can use a filter to it's full life without problems. We are at present looking at introducing citrate instead of heparin to try an cut down on the complications and conserve the life of the filters.
I am at present looking at the warming of septic patients!
We use predominantly CVVHD in this setting. And following the same evidence as Stephen Lapinsky we prefer citrate, unless systemic heparinisation is indicated for another reason. Historically we avoided citrate in patients with liver dysfunction, but are using it more and more in these patients too, especially if the liver function has "stabilised", i.e. not worsening each day.
We as a unit are considering transferring to citrate in the use of our CVVHDF, but as yet there is some reluctance to do so.
With regards to the use of Heparin, there needs to be tight control of it's use, especially in the regards to conserving the filter lifespan and patient condition, with therapeutic ranges being difficult to reach in an effective time span to conserve the filter and stop it clotting off. With epoprostenol, it is the monitoring of the filter pressures. It is down to personal preference as to which product is used, and how effective they utilise this product.
Cytokines clearance is not the only explanation for the beneficial effect of CRRT and a moderate cooling, a high rate of fluid exchange between interstitial and intravascular compartments or a fast normalization of pH (a proinflammatory stimulus that conditions vasopressor unresponsiveness) can in part explain this beneficial effect (and these mechanisms are shared by diffusion and convection), but clearance of cytokines is the central key factor proposed as mechanism for hemodynamic improvement and the intrinsic capability of high dose CRRT to clear cytokines (based in convection) is an attractive theory that rests on sound experimental studies. So, until more evidence is at our disposal, and having always in mind that use of CRRT aiming to modulate the septic process must be considered an experimental procedure, we aim for convective/adsorptive therapies with preference over isolated diffusion. So, in general we aim for high dose convection, complement dose when technically necessary with diffusion (J Trauma Acute Care Surg, 2012; 73:855-60) and in special cases (very early, gram-negative suspected, abdominal focus) adsortion may be preferred.
I was wondering how can CVVHD be applied to citrate use as we consider neccesary to reinfuse citrate fluid (prismocitrate in our case) prefilter. That means that at least CVVHDF would be neccesary. I´m not so sure about CVVH...Citrate experts?
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