To The Editor:
I read with great interest "Rattlesnake Bites in Children: Antivenin Treatment and Surgical Indications" (2002;84:1624-9), by Shaw and Hosalkar. I was, however, perplexed by the conclusions drawn by the authors. The authors reported on a retrospective review of twenty-four patients managed at their hospital. They did not report on a trial that compared specific treatment methodologies.
In the Discussion, the authors made two statements that concern me. First, they stated: "We believe that fasciotomy and/or débridement in the face of acute tissue toxicity creates further morbidity and should be avoided whenever possible." The information available in the authors' paper does not support this statement. While I agree that prudent practitioners exercise caution when recommending fasciotomy, in selected cases it is necessary. According to the authors' own report, the single patient in this study who underwent a fasciotomy convalesced without significant complications.
The authors also stated that they "believe that surgery for rattlesnake bites is indicated for patients who have a confirmed compartment syndrome that is refractory to antivenin treatment." The implication is that antivenin is a treatment for acute established compartment syndrome. Antivenin has never been shown to be a treatment for acute established compartment syndrome. The treatment of choice for such syndromes of the extremity is fasciotomy.
The authors presented an interesting single-cohort retrospective review with a 33% rate of long-term follow-up. While, in general, I agree with their treatment regimen, the aforementioned statements in the Discussion cannot be supported by the data in their article.
B.A. Shaw replies:
Dr. Seiler states that the data in our retrospective study do not support two of our conclusions. With respect to study design, he may be correct; this was not a controlled, prospective, blinded study with statistically significant findings and therefore was not as rigorous as perhaps other studies published in
The Journal. However, designing such a study and obtaining institutional review board approval, especially for a study of children, would be extremely challenging and perhaps take a decade or more to complete as a result of the extreme rarity of compartment syndromes following rattlesnake bites. Given the combination of data obtained in our study and the wealth of data obtained from studies of adult envenomations published before and after ours, we stand by our conclusions.
First, surgery for any condition, including snakebite, always carries a certain level of morbidity and potential for complications. Incising a traumatized or envenomated extremity adds morbidity. When débridement is performed, one cannot visualize the venom to remove it, and damaged tissues are exposed to possible bacterial contamination. Additionally, there are no established guidelines for determining precisely which tissues should be débrided because of envenomation. Intravenous antivenin can reach all tissues that still have an effective blood supply and neutralize the venom throughout the extremity and systemically.
Second, Dr. Seiler disputes our conclusion that "surgery for rattlesnake bites is indicated for patients who have a confirmed compartment syndrome that is refractory to antivenin treatment." Subsequent to our study, Hall reported a series of 1257 cases, for which only two fasciotomies were required
1 . For confirmed compartment syndromes (pressure over 30 mm Hg), Walter et al.
2 recommended giving an additional twenty vials of antivenin and waiting up to four hours for reduction to <30 mm Hg. We presented a single unpublished case in which compartment pressures decreased to <30 mm Hg following antivenin treatment in a child. Gold et al.
3 , in their recent review article, also recommended that additional antivenin be given in cases of established compartment syndrome, pointing out that fasciotomy "does not prevent the progression of envenomation, treat coagulopathy, or obviate the need for additional antivenom . . . may substantially lengthen the course of treatment, and may be associated with nerve damage, disfiguring scars, contractures, and loss of limb function."
3 In their seminal laboratory work on a dog model, Garfin et al. definitively showed the ability of antivenin to decrease compartment pressures from 49 to <30 mm Hg within several hours after administration
4 . They also showed that the permanent muscle necrosis was due to the venom itself, rather than to elevated compartment pressures
5 . There is no evidence that fasciotomy can prevent or reverse venom-induced myonecrosis.
Finally, Dr. Seiler mentions our "33% rate of long-term follow-up," and we admit this weakness; however, our short-term follow-up (at the time of discharge) was 100%, and any serious impairments were likely to have appeared by then.
In the setting of less-than-perfect data, we maintain that antivenin and more antivenin should always be the first treatment for severe rattlesnake envenomation and that literature written since our publication supports this position. We thank Dr. Seiler for the opportunity to debate this issue.