University of Alabama at Birmingham

2001 Case #4

Universidad Peruana Cayetano Heredia
 
The following case was seen in the Medical Intensive Care Unit at Cayetano Heredia Hospital in Lima by the 2001 Gorgas Course participants.
Image for 02/09/01History: 25 yo male bitten on left leg by a snake 12/28/00. Oral bleeding and hematuria were noted en route to hospital. Despite polyvalent antivenin administered IV within 24 hours, progression of leg edema to severe necrosis. Transfused on 01/03/01. Transferred to Lima for skin grafting on 01/25.

Epidemiology: Outdoor laborer in rural area of Junin Department in the Amazon jungle.

Physical Examination: Left thigh and leg shown in photograph as seen 02/05/01 after skin grafting over exposed muscle and bone on 01/25 & 01/31. Several debridements had been performed over the previous 4 weeks.

Labs: On initial presentation: Hematocrit 19, WBC 9.5K. INR-1.29. Normal renal function.



University of Alabama at Birmingham

2001 Case #4
Diagnosis and Discussion

Universidad Peruana Cayetano Heredia
 
Diagnosis: Severe local necrosis by venom of Bothrops atrox (fer-de-lance), a common neotropical pit viper in South America.
Discussion: Severe local necrosis and hemorrhage is more characteristic with vipers and pit vipers than with elapid snakes (cobras, mambas, coral snakes, kraits and others). Species of Bothrops account for most of the serious snakebite in Latin America and range from Mexico to Argentina. Bothrops can adapt to habitats varying from grasslands to rainforest. These are medium to long snakes (0.7 to 2.5 m) with heat-sensing pits between eyes and nostrils. In addition to the significant local necrosis usually seen, essentially any other organ system may be involved including cardiovascular, renal, hematologic, and CNS. In contrast, with Elapids, local findings are mostly insignificant and early neurotoxicity often manifest by cranial nerve dysfunction (ptosis, opthalmoplegia) is most prominent.

Although details from the referring hospital are incomplete, this patient did receive appropriate polyvalent antivenin according to standard Peruvian protocols. This includes a test dose followed, as in this case, by 6 vials of antivenin given by slow IV push. Despite this and adequate hydration the severe necrosis rapidly ensued. Fortunately the bleeding stopped at that time.

Unfortunately, soon after the skin grafts were placed and despite good wound care, the patient developed a gram negative sepsis with hypotension and requiring intubation. This is a frequent complication in patients with this degree of necrosis. After 4 days in ICU the sepsis was treated successfully and patient was discharged back to the ward.

Fatalities due to Bothrops envenomation are common among indigenous peoples in the Amazon basin. The snakes are not aggressive and will only attack if disturbed. Travelers should be educated to be alert when walking in the rainforest. The use of first aid measures such as compression and immobilization in viperidae envenomation is highly controversial and the aim should be to transport to hospital care quickly. Expedition travelers to remote locations can consider carrying a supply of antivenin but its use does not obviate the need for rapid transport to a medical facility for management of IV fluid administration and support of cardiorespiratory compromise that may ensue.