Toxicology posts by agent
Hemoperfusion for intoxications
- By Dr. Scherly Leon
In 2014, about 2.2 million human exposures were reported to a poison control center in the United States. Many of these exposures led to visit in a healthcare facility. The exposures often require supportive care but when necessary extracorporeal treatments like intermittent hemodialysis (IHD), continuous renal replacement therapy (CRRT), hemoperfusion (HP), exchange transfusion, and extracorporeal membrane oxygenation (ECMO) may be required for the management of such exposures. The EXTRIP workgroup has produced a concise review that covers the history, technical aspects and utility of hemoperfusion.
What is hemoperfusion?
An extracorporeal form of treatment, blood is pumped through a device outside the body and passing through a column with absorptive properties with the goal of removing specific toxic substances from the blood.
What is the mechanism?
HP removes small to medium sized molecules that are more difficult to remove by hemodialysis. The adsorbent substances most commonly used in hemoperfusion are activated charcoal (binds hydrophilic compounds) and resins (binds lipophilic compounds). However, eventual saturation of this absorbent material also means that the abdsorbent cartridge has to be replaced after 3-4 hours if longer treatment is required.
What toxins/drugs are removed with hemoperfusion?
Dialysis generally removes low molecular weight, water-soluble molecules which are not protein-bound while hemoperfusion is considered for removal of high molecular weight, highly-protein bound molecules. Some of the drugs traditionally considered to be removed better by hemoperfusion compared to hemodialysis are theophylline, barbiturates, phenytoin and valproic acid.
What are complications of hemoperfusion?
Complications of hemoperfusion may include severe thrombocytopenia, leukocytopenia, hypocalcemia, hypophosphatemia and hypoglycemia. The risk of bleeding is also higher because of reduction in platelets and clotting factors.
Overall, given these significant complications, higher cost and technical complexity, and lack of data about its superiority compared to hemodialysis hemoperfusion use has decreased significantly in the US in recent years. However, it is still used in certain parts of the world for treatment of pesticide overdoses (eg paraquat).
About the author
Scherly Leon is completing nephrology fellowship at SUNY Downstate Medical Center this month. She is passionate about patient education, health advocacy, policy, and disparities. She tweets at @SLeonMD.