Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Venom induced pressure elevation reversible syndrome: a severe pediatric rattlesnake envenomation, evidence for conservative management, and call for naming the syndromeVenom induced pressure elevation reversible syndrome: a severe pediatric rattlesnake envenomation, evidence for conservative management, and call for naming the syndrome

 


Venom induced pressure elevation reversible syndrome: a severe pediatric rattlesnake envenomation, evidence for conservative management, and call for naming the syndromeVenom induced pressure elevation reversible syndrome: a severe pediatric rattlesnake envenomation, evidence for conservative management, and call for naming the syndrome

Abstract

Introduction: Rattlesnake envenomation frequently mimics traumatic compartment syndrome, as both are characterized by severe pain, swelling, and elevated compartment pressures. Unlike traumatic compartment syndrome there have been no documented cases of ischemic limb injury after envenomated patients have received antivenom. Furthermore, there is experimental evidence that fasciotomy worsens myonecrosis. This has led medical toxicologists and surgical guidelines to shift from liberally recommending fasciotomy to near universal recommendation of antivenom alone. Despite this, fasciotomies continue to be recommended and performed on rattlesnake envenomated patients. This case highlights a pediatric patient who met objective criteria for compartment syndrome and received repeated recommendations for surgical intervention but was successfully treated with antivenom alone.

Case presentation: A 5-year-old female presented with respiratory failure, hypotension, and a tense, ecchymotic right lower extremity without distal pulses following a rattlesnake bite. The patient met criteria for compartment syndrome and emergent fasciotomy was recommended by orthopedic surgery. After multidisciplinary discussions, surgical intervention was deferred in favor of medical management with antivenom. The patient received a total of 30 vials of Crotalidae immune F(ab’)2 antivenom (Anavip®), in addition to limb elevation. Following antivenom administration, serial measurements showed a progressive decline in compartment pressures over the first 24 hours. While the initial exam was consistent with traumatic compartment syndrome, the patient improved with medical management alone and was discharged on hospital day seven. Long-term follow-up confirmed a return to unassisted ambulation without neurovascular impairment or tissue loss.

Discussion: This case demonstrates that elevated pressures from rattlesnake envenomation can be reversed with antivenom therapy. Despite clinical similarities, traumatic compartment syndrome and venom-induced pressure elevations require different treatment strategies.

Conclusion: We propose the term Venom Induced Pressure Elevation Reversible Syndrome (VIPERS), to clearly differentiate the diagnosis from traumatic compartment syndrome. Furthermore, to avoid unnecessary surgical intervention, any consideration for fasciotomy should involve a medical toxicologist experienced in managing rattlesnake envenomation.


Lippi, M., Metri, S., Cook, L., Lapoint, J., Clark, R., Seltzer, J., … Hardin, J. (2026). Venom induced pressure elevation reversible syndrome: a severe pediatric rattlesnake envenomation, evidence for conservative management, and call for naming the syndrome. Clinical Toxicology, 1–8. https://doi.org/10.1080/15563650.2026.2700396