A Cobra Bite Mimicking Coma in a 2-year-old

A previously healthy 2-year-old boy was hospitalized following an unexplained sudden cardiac arrest. Thirty minutes before the cardiac event, his right foot had become trapped between floor gaps at home, causing it to submerge in sewage. Distressed, he ran to his mother, who took him to the first hospital.

During the initial assessment of his vital signs, he suddenly experienced air hunger, with unmeasurable oxygen saturation, collapsed, and became pulseless. Immediate cardiopulmonary resuscitation (CPR) and intubation were performed without medication. He regained spontaneous circulation, and his vital signs stabilized after 2 minutes of resuscitation.

Upon examination, the child was comatose with fluctuating blood pressure and heart rate. He exhibited no spontaneous breathing, had fixed pupils of 3 mm, and lacked oculocephalic and gag reflexes. He displayed severe hypotonia, no muscle response to noxious stimuli, and absent deep tendon reflexes, plantar responses, and clonus. There was no neck stiffness. A bruise was observed at the medial right malleolus, but no fang marks were evident.

Laboratory tests, including complete blood count, serum electrolytes, and coagulogram, were normal. Venous clotting time was 8 minutes. Electrocardiography revealed no heart rhythm abnormalities, and the echocardiogram showed no structural heart issues. Electroencephalography (EEG) was unremarkable during both wakefulness and sleep. Computed tomography scans with contrast media indicated generalized brain edema and white cerebellum sign.

Two days after admission, the patient's neurological status remained unchanged, with no brainstem reflexes, voluntary movement, or spontaneous breathing. The bruise on his right ankle extended below the knee, showing necrotic changes.

Considering the frequent presence of cobras in the patient’s suburban home and the skin necrosis resembling a cobra bite, cobra envenomation was suspected. Thai cobra antivenom was administered, and within twenty minutes, the patient began to exhibit minimal eye and limb movements. He was extubated one day after the antivenom administration.

Over several weeks of rehabilitation, he gradually recovered without lasting neurological impairments. ELISA confirmed the presence of cobra venom toxins in the patient’s serum, verifying the diagnosis of cobra envenomation.

The cobra bite induced cardiac arrest and mimicked brain death by causing the absence of brainstem reflexes, spontaneous movements, and respiration. This case highlights the importance of considering venomous snake bites in similar clinical presentations, even in the absence of fang marks, and underscores the value of EEG in evaluating comatose patients.

Source: Mekmangkonthong A, Khusiwilai K, Paticheep S, et al. Case Reports in Pediatrics. 2024;2024(1):6630842.