Severe systemic myotoxicity with massive rhabdomyolysis following Ovophis anitae envenomation: a case report.

BACKGROUND: Ovophis anitae (O. anitae) is a recently recognized mountain pit viper endemic to northern Vietnam and adjacent southern China. Human envenomation remains exceedingly rare, and its clinical manifestations are incompletely characterized. Published reports have primarily described local tissue injury and mild coagulation abnormalities, whereas life-threatening systemic toxicity has not been well documented. We report a patient with independently confirmed O. anitae envenomation who developed extensive local tissue injury, massive rhabdomyolysis, severe metabolic acidosis, respiratory failure requiring mechanical ventilation, and complete recovery following comprehensive intensive supportive care.

CASE PRESENTATION: A previously healthy 17-year-old Vietnamese male was bitten on the dorsum of his left foot while collecting forest fruits in Lao Cai Province, northern Vietnam. The patient had no known chronic medical illnesses, previous episodes of rhabdomyolysis, neuromuscular disorders, endocrine or metabolic diseases, regular prescription medications, herbal remedies, dietary supplements, or performance-enhancing substances. He denied alcohol misuse, recreational drug use, recent febrile illness, strenuous exercise, seizures, trauma, or prolonged immobilization before the snakebite. The offending snake was photographed immediately after the bite and independently identified as Ovophis anitae by two experienced herpetologists based on external morphological characteristics. Approximately 13 hours after envenomation, he was admitted to the Vietnam National Poison Center with rapidly progressive limb swelling, marked rhabdomyolysis, metabolic acidosis, leukocytosis, and progressive skeletal muscle injury. No species-specific antivenom was available, and no antivenom was administered. During hospitalization, serum creatine kinase exceeded 200,000 U/L, accompanied by marked hypertransaminasemia while renal function remained relatively preserved. Progressive deterioration with worsening metabolic derangements and respiratory failure necessitated endotracheal intubation, invasive mechanical ventilation, continuous venovenous hemofiltration was initiated for severe metabolic acidosis and metabolic complications of massive rhabdomyolysis despite aggressive medical management. Because progressive systemic deterioration persisted despite maximal supportive care, therapeutic plasma exchange was subsequently undertaken as an individualized rescue intervention rather than evidence-based standard therapy. Serial clinical, laboratory, rotational thromboelastometry, ultrasonographic, and electrophysiological evaluations documented gradual recovery. The patient was extubated on hospital day 9 and discharged without neurological deficits or functional impairment.

CONCLUSIONS: This case expands the currently recognized clinical spectrum of Ovophis anitae envenomation by demonstrating that this uncommon mountain pit viper may cause life-threatening systemic toxicity characterized by massive rhabdomyolysis, severe metabolic derangements, and respiratory failure despite only mild coagulation abnormalities. Early recognition, meticulous intensive care, and aggressive supportive management may result in complete recovery.