Studies

China, Guangxi Zhuang Autonomous Region
Sawai et al. 1992: 12 Ophiophagus hannah bites; identification: 10/12 bites occurred in snake catchers, who can certainly be assumed to have correctly identified the snake that caused the bite. Along with N. n. atra and Deinagkistrodon acutus, Ophiophagus hannah has a high commercial value in the region in which the study was carried out.

Case reports

Wetzel and Christy 1989: 1 case; identification: morphological.

Burma
Tin-Myint et al. 1991: 3 cases; identification: morphological; review of the literature on Ophiophagus hannah.

Malaysia
Muthusamy and Gopalakrishnakone 1990: 1 case; identification: description by patient and a companion, recognition from photos.

Tun-Pe te al. 1995: 2 cases; identification: morphological.  Boosted venom IgG response in the patient with previous bites and recent traditional immunization.

Thailand
Ganthavorn 1971: 1 case; identification: morphological.

Signs & symptoms

Local effects

Local pain and swelling (Ganthavorn 1971, Muthusamy and Gopalakrishnakone 1990, Wetzel and Christy 1989), local blistering (Ganthavorn 1971, Muthusamy and Gopalakrishnakone 1990), superficial necrosis (Ganthavorn 1971, Muthusamy and Gopalakrishnakone 1990).

Local swelling 2/3, extensive in 1 patient with 47% increase in the circumference of the arm; necrosis 1/3, surgical debridement necessary (Tin-Myint et al. 1991).

Local swelling 10/12, necrosis 3/12 (Sawai et al. 1992).

Neurological effects

Preparalytic phase: 30 min (ptosis), 70 min (dysphagia, respiratory paralysis) (Ganthavorn 1971); 60 min (ptosis) (Muthusamy and Gopalakrishnakone 1990).

Blurred vision (Wetzel and Christy 1989, Muthusamy and Gopalakrishnakone 1990), ptosis (Ganthavorn 1971, Muthisamy and Gopalakrishnakone 1990), dysphagia (Ganthavorn 1971, Muthusamy and Gopalakrishnakone 1990), generalised muscle weakness (Ganthavorn 1971, Wetzel and Christy 1989, Muthusamy and Gopalakrishnakone 1990), paralysis of the respiratory musculature with respiratory failure (Ganthavorn 1971).

Dysarthria, ptosis, flaccid paralysis of the skeletal musculature, respiratory failure. The patient appeared to be unconscious, but had actually maintained consciousness: was able to indicate 'yes' and 'no' by moving a finger (1/3) (Tin-Myint et al. 1991).

Signs of paralysis 8/12 (Sawai et al. 1992).

Other signs & symptoms

Vomiting (approx. 1 h after the bite).

Arterial hypotension (systolic blood pressure fluctuating between 50 and 90 mmHg) over a period of many hours (possible venom-induced vasodilatation or hypovolaemia due to sequestration of fluid in the swollen extremity) (Tin-Myint et al. 1991).

Euphoria, hallucinations, headache (Wetzel and Christy 1989).

Case fatality rate

7/12; time interval between the bite and death 1.5–10 h (Sawai et al. 1992).

Morbidity

Necroses 3/12 (Sawai et al. 1992).

Treatment (symptomatic)

Successful artificial respiration; restoration of spontaneous respiration after 19 h (Ganthavorn 1971); after 64.5 h (Tin-Myint et al. 1991).

Treatment (specific)

Antivenom

King cobra antivenom (QSMI, Bangkok).

Efficacy

1. Neurotoxic signs of envenoming
   1,150 ml (Ganthavorn 1971): King cobra antivenom (QSMI, Bangkok) with no convincing effect; the patient required artificial respiration for 19 h despite this large dose of antivenom.
   500 ml of King cobra antivenom (QSMI, Bangkok) (Wetzel and Christy 1989): no convincing effect; the patient received a total of 250 ml of specific antivenom in the first 4 h after the bite but the neurological signs deteriorated in spite of this.
   320 ml of paraspecific antivenom (Cobra antivenom, Twyford, Ludwigshafen) (Muthusamy and Gopalakrishnakone 1990): no convincing effect; it took 24 h for the neurological signs and symptoms to disappear.
2. Local swelling, necroses
   None of the 3 patients from the case reports suffered serious local consequences of the envenoming. However, due to the small number of patients, a local anti-cytotoxic effect of the antivenom cannot be proven.

Adverse reactions
King cobra antivenom (QSMI, Bangkok): chills in the 3 h following administration of antivenom (possibly a pyrogenic reaction).
Serum sickness (rash, joint pain) (Wetzel and Christy 1989). Serum sickness (urticarial rash) (Ganthavorn 1971).