Get hurt while hiking AUTHOR DR. TOMMY LAM SHING KIT NOV., 2013 HKCEM College Tutorial

Triage (Category II) ▪ Female 40 year old ▪ Hiking with friends weekend ▪ Get hurt over left ankle in grass ▪ ? Bitten ▪ BP 158/94 ▪ Pulse 100/min ▪ Temp 37.2 °C 2

Assessment ▪ Assess and stabilize ABC if necessary 3

Physical Exam ▪ Is it a snake bite ? ▪ Is it a dry bite/ non venomous snake bite ? ▪ Is there envenomation ? ▪ Local sign and symptom? ▪ Systemic sign and symptom ? 4

Left ankle 5

Physical Exam ▪ Fang mark, Number of fang mark ? ▪ Swelling ? Longitudinal and involved joint ▪ Progression ? Mark by “marker” at different time or taking photo ▪ Clinical compartment syndrome? ▪ Ecchymosis ? ▪ Blisters? ▪ Necrosis? 6

4 hours later 7

Snake identification ▪ History taking ▪ Any snake specimen available ? ▪ What we can do if in doubt on the snake specimen ? ▪ Consult snake identification from Kadoorie Farm & Botanic Garden (KFBG) 8

Poisonous snake in HK ▪ Viperidae ▪ Colubridae ▪ Elapidae ▪ Hydrophidae 9

Local features ▪ Pain ▪ Bruising ▪ Blister ▪ Necrosis 10

Systemic features ▪ Bleeding tendency ▪ Oozing from the wound 11

Neuromuscular ▪ Breathing difficulty ▪ Paresthesia ▪ Ptosis, diplopia ▪ Dysphagia ▪ Muscle weakness 12

Clinical Feature SnakeFeature CobrasSevere local pain and swelling, blister, and necrosis (neurotoxic symptoms if king cobra) Vipers or pit viperSevere local pain with incoagulable blood KraitAbsent or mild local symptom with neurotoxic symptoms 13

Investigation ▪ Complete blood picture (especially Platelet count) ▪ Renal and liver function test ▪ Clotting profile ▪ Fibrinogen ▪ ECG ▪ Urine for RBC  Need serial blood tests if present too early 14

Treatment ▪ Remove constricting object from injured part or limbs (e.g. remove ring if bitten finger) ▪ Dressing ▪ ATT ▪ Analgesic ▪ Antibiotic for infected wound or significant local reaction ▪ Antivenom 15

Some Poisonous Snake in HK ▪ Green Pit Viper/ Bamboo Snake/Cryptelytrops albolabris/ 青竹蛇 16

Some Poisonous Snake in HK ▪ Chinese Cobra/Naja atra/ 眼鏡蛇 / 飯鏟頭 17

Some Poisonous Snake in HK ▪ King Cobra/Ophiophagus hannah/ 眼鏡王蛇, 過山烏 18

Some Poisonous Snake in HK ▪ Many-banded Krait/Bungarus multicinctus/ 銀腳帶 19

Some Poisonous Snake in HK ▪ Banded Krait/Bungarus fasciatus/ 金腳帶 20

Some Poisonous Snake in HK ▪ Red-necked Keelback/ Rhabdophis subminiatus/ 紅脖游蛇 21

Common envenomation syndrome FamilyClinical Feature ViperidaeCytotoxic, vasculolytic and haemotoxic ElapidaeNeurotoxic and local tissue necrosis HydrophidaeRhabdomyolysis, hyperkalaemia and renal failure ColubridaeLocalized pain, swelling, haemolysis and coagulopathy 22

Antivenom for common snake bite in HK Antivenom Viperidae Bamboo Snake 青竹蛇 Green Pit Viper/ Agkistrodon halys Mountain Pit Viper 山烙鐵頭 Agkistrodon halys Elapidae Chinese Cobra 眼鏡蛇, 飯鏟頭 Naja naja King Cobra 眼鏡王蛇, 過山烏 King Cobra Banded Krait 金腳帶 Banded Krait Many-banded Krait 銀腳帶 Bungarus multicinctus 23

Pretreatment ▪ Antihistamine -- Piriton (Chlorpheniramine) ▪ Hydrocortisone ▪ Watch out for anaphylaxis or anaphylactoid reaction 24

Our patient ▪ Present with mild wound pain and snake specimen confirmed Green Pit Viper ▪ Observation after 24 hours ▪ Pain controlled by analgesics ▪ Serial blood tests revealed no systemic involvement ▪ Discharge uneventfully 25

Thank you 26