Renal replacement therapy (RRT) using an adsorbent cartridge to remove circulating toxins
Hemoperfusion may be considered for agents with high volumes of distribution if:
- agent is not cleared by liver or kidneys, or clearance is impaired by organ failure
- agent is not removed by dialysis or hemofiltration
- agent causes significant illness
Indications are controversial
- Toxicology: anti-epileptic drugs (e.g. carbamazepine, valproate, phenytoin, barbiturates), theophyline
- renal failure with aluminum intoxication
Many other agents bind hemoperfusion cartridges in vitro and in animal models but clinical utility is not established. Similarly, for endotoxin, superantigens and harmful cytokines.
- RRT with an adsorbent charcoal cartridge or an ion exchange resin (e.g. XAD 4 amberlite)
- Charcoal hemoperfusion results in irreversible binding
- resin hemoperfusion reversibly binds toxins via hydrogen bonds and Van Der Waal’s forces
- charcoal is coated with an ultrathin film to prevent hypersensitivty reactions and charcoal embolisation (major problems with early hemoperfusion cartridges)
METHOD OF USE
- blood flow rate typically 150-300 mL/min
- standard CVVH circuit with an adsorbant cartridge instead of a semi-permeable filter
- requires anticoagulation (may need high doses of heparin due to adsorption)
- cartridge is primed (usually 2-3L saline or dextrose solution depending on the model)
- The hemoperfusion cartridge usually gets saturated and requires replacement after 3-4 h
- Molecular weight, protein binding and lipid solubility do not significantly influence hemoperfusion
- selective sorbents have been developed (e.g. using ligands specific for agents such as endotoxin)
Venous access complications
- see central line / vascath
Complications due to exposure to charcoal filter (bioactivation and mechanical effects)
- Thrombocytopenia (30%)
- Leucopenia (10%)
- Coagulopathy (e.g. low fibrinogen)
- sorbent embolisation (major issue with early uncoated cartridges)
Complications of anticoagulation
References and Links
FOAM and web resources
— Indications for hemoperfusion
— Complications of hemoperfusion
— Hemoperfusion: The hemoperfusion circuit
— Selectivity of sorbents and efficiency of adsorption
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.