Of snakes and their bites

Toxicology is the study of poisons, including the source, effect and treatment of poisoning. This was the first sentence I was taught in toxicology class by Dr Willis Ochieng’. 

Dr Ochieng’ taught us many strange things about toxins and poisons, but he definitely did not prepare me for Master Felix*. One lazy Sunday afternoon, we were having a slow day at the emergency department at a middle level hospital where I was moonlighting as a young practising doctor. The emergency department has never been my favourite place to work but I needed the money and the learning experience was great. 

My colleague and I hung around drinking tea and telling stories, wiling the shift away until about 5.30pm, when we heard a car drive in. The triage nurse called us to the emergency area where we found a six-year-old girl having an asthmatic attack. My colleague took over and I retreated to give the team space. She was hooked onto a nebulizer in no time. 

As I walked back to the consulting room, I heard another car pull up, brakes screeching loudly in the little parking lot. They did not wait for the nurse to get out but a man alighted and ran into the emergency department carrying a young boy, approximately 10 years old. I ran through the back door to the emergency room to find the man urgently announcing that young Felix had been bitten by a snake and needed anti-snake venom. 

Felix was on the examination couch and a quick exam noted he had a pair of neat puncture wounds just above his left ankle. The whole leg was wrapped up firmly in a crepe bandage to minimise absorption of the venom. We quickly set about hooking him to monitors and securing intravenous access.

The dad quickly narrated that he had gone with Felix to the family farm in Malili, Machakos County, which is quite bushy due to the season. Felix had gone to explore the farm and had come across a snake, accidentally stepping on it before he saw it, getting himself bitten in the process. They had stopped at four facilities along the way and none had anti-snake venom. He wanted to know if we had it in stock. 

Right then, the driver who had brought Felix and his dad came into the room carrying a plastic bag. He walked up to me and opened it up right in my face, revealing a large grey and cream-patterned snake, about a meter long! Well, I am a true ophidiophobic, irrationally scared of snakes. I high-tailed out of the emergency room screaming, white coat notwithstanding!

For generations, it has long been recommended that once bitten by a snake, one needs to bring it along for easy identification, to aid in treating the snake bite victim. It is time to set the record straight, unless one is a herpetologist, very few people can truly tell you the type of snake you are dealing with, its venom type and toxicity, if at all venomous. For most doctors in Kenya, the closest they may have come to a snake is at the museums and snake parks, if not on National Geographic! 

Only about 10 per cent to 15 per cent of all snakes are venomous. The toxins vary and hence affect the body differently. There are those that damage the lining of the blood vessels and the blood coagulation function, resulting in leakage of blood and uncontrolled bleeding due to failure to clot. 

Other toxins damage nerves, interfering with their function, causing paralysis of muscles including critical muscles of the heart and for respiration. Less commonly are toxins that destroy muscle cells, causing them to break down and release a pigment called myoglobin, which in large quantities can cause damage to the kidneys; resulting in renal failure. 

Treatment of snake bites is not just antivenom — supportive treatment is equally important. Anti-snake venom may be monospecific, where it is made for a specific type of venom; or may be polyspecific, made for an array of venoms. For the monospecific anti-snake venom to work, one needs to have the snake and the testing kits to confirm the type of venom then treat. This is difficult and expensive in most cases, especially where time is of essence, hence the reason  for stocking the multispecific type. 

The anti-venom is given as an intravenous infusion and the dose may be repeated multiple times until the venom effect is fully neutralised. It is worth noting that the anti-snake venom itself may cause severe anaphylaxis (severe allergic reaction)  hence the need for it to be administered in an emergency department or even in an intensive care unit that is ready to handle the complications. Otherwise, the patient may die from the attempted treatment long before the venom gets to him. 

The complications arising out of the bite must be addressed, too. Blood transfusion, dialysis, cardiorespiratory support in the intensive care unit, pain management and fasciotomy - surgery to release compressed muscles and blood vessels in extremely swollen limbs, may be required depending on the venom type and its effects on the body.

Young Felix did well on a single dose of anti-snake venom, wound care, pain killers and antibiotics and was able to go home the next day after monitoring. I could care less how the snake was disposed of. I just wanted it gone. I doubt I could ever redeem myself in Felix’s eyes but well, he lives to tell the story of the cowardly doctor!

Dr Bosire is an obstetrician/gynaecologist