Letters To the Editor: September 2014
Epidural Steroid Contaminants
Thank you for publishing the recent article about Adhesive Arachnoiditis by Dr. Forest Tennant.1 I wish to point out one important error of factual information, however.
In discussing the events of inoculation of fungal contaminants with epidural steroid injections, Dr. Tennant stated: “The offending agent was a mold known as Exserohilum rostratum.” I submit that Exserohilum was the cause of only the most dramatic consequences, but it is probably not “the (only) offending agent.”
In fact, Exserohilum is only the most notorious offending agent. The bellwether case was caused by Aspergillus as the primary infectious agent, with one postmortem tissue sample growing Cladisporium species. Recent publications have identified evidence of 13 and 10 different fungal species in victims of this event, respectively.2,3 The CDC and FDA have identified numerous species of fungus in vials from the contaminated lots.4
In the first publication, Gade et al analyzed tissue samples obtained in surgery and/or at postmortem examination.2 They reported 13 different fungal species contaminating these human tissues. They did not examine blood or other body fluids that are easy to obtain in living subjects.
Zhao et al reported on using PCR analysis of blood and joint fluids obtained from surviving, but symptomatic victims of inoculation with contaminated steroids. The researchers found evidence of RNA of 10 different fungal species in these fluids obtained months after epidural steroids were delivered. The PCR test used is not commercially available, and it is effectively not available because it would cost about $500 per test.
These two reports raise many unanswered questions and attention is diverted away from full clinical evaluation by focusing only on Exserohilum. How pathogenic are these other species of fungus when inoculated into the epidural space and/or surrounding tissues? Are they responsible for many cases of arachnoiditis? The fact that fungal RNA fragments are identified a full year or more after patient exposure has frightening implications for ongoing clinical management.
On a more general note, these events raise the question as to whether previously unidentified, and probably unidentifiable, fungal contamination is in fact a cause of at least some cases of arachnoiditis.
The unfortunate focus on Exserohilum is preventing full diagnosis and optimal clinical management of the people who have ongoing symptoms and subtle but active disease.
Richard C. Dobson, MD (retired)
Dear Dr. Dobson,
You are absolutely correct, and we appreciate your detailed summary of infections following injection of contaminated corticosteroid solutions. In our future writings, we will not refer to the single fungal agent Exserohilum rostratum, but add Aspergillus and other fungi as well.
Forest Tennant, MD, DrPH
Opioid Calculator Daily Dose
I was just introduced to your opioid calculator. While I think it is a very good resource, I did uncover a potential medication error issue that I wanted to bring to your attention. When selecting the link to begin an opioid on an opioid-naive patient, I chose the <50 kg choice to see how this would work for a potential pediatric patient. When I selected morphine IV, the dose displayed with the header “Starting DAILY dose” was 0.075 mg/kg Q4-6.
Having a pediatrics background, I am very sensitive to the errors that can result from
mg/kg/DAY compared with mg/kg/DOSE. This result is clearly
mg/kg/DOSE yet the heading suggests that it is a daily dose. This might be something that you would want to clarify to prevent future potential errors in dosing.
Sheri Flatt, PharmD, BCPS
Dear Dr. Flatt,
You are correct. The calculator does say daily dose—and then it gives the single dose to be given every 4-6h. I checked about 10 other choices, and it always gives the single dose for the answer. We will get rid of the word ‘DAILY’ in Starting daily Dose, but leave the word ‘daily’ for the Max daily Dose line.
Editor’s Note: This change has been made to the Opioid Calculator.
Jeffrey Fudin, BS, PharmD