Abstract
To the Editor:
We found the description of 2 cases of severe Amanita phalloides (AP) toxicity interesting and are grateful that physicians continue to strive to improve care for such patients. 1 However, we are concerned that the description of success attributed to hemodialysis (HD) with a medium cut-off membrane may prompt unnecessary intervention or transfer of patients to receive HD based on very low quality and incomplete evidence of benefit. Broad supportive care measures are the mainstay of treatment for AP toxicity, including intravenous fluid administration and maintenance of normal electrolyte concentrations. Studies of other treatments directed specifically at AP toxicity, such as N-acetylcysteine and silibinin, yielded mixed results. 2 -5
Similarly, studies of HD in patients with AP toxicity report conflicting results and are limited by confounding treatments, uncontrolled observations, and lack of data to demonstrate amatoxin clearance.6,7 In the current study, HD was performed for renal replacement and thus served a supportive care role for the patient.
The authors’ conclusion that the use of an HD membrane with amatoxin filtering possibly reduced toxicity is unsupported in their study because no data demonstrating amatoxin removal are reported. In fact, prior studies reported little if any circulating amatoxin at the time patients can reasonably be started on HD.6,8 Future studies aiming to demonstrate a benefit of HD in AP toxicity must measure some form of amatoxin clearance. Without direct evidence of removal of toxin, HD seems to provide useful but ultimately only supportive care.