{"id":29,"date":"2010-01-20T16:23:16","date_gmt":"2010-01-20T10:53:16","guid":{"rendered":"http:\/\/www.snake-scorpion.com\/?page_id=29"},"modified":"2010-01-20T16:23:16","modified_gmt":"2010-01-20T10:53:16","slug":"1-3-clinical-aspects-of-snake-bite","status":"publish","type":"page","link":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/section-i-snakebite\/1-3-clinical-aspects-of-snake-bite\/","title":{"rendered":"1.3 Clinical aspects of Snake Bite"},"content":{"rendered":"

Pathophysiology:
\nSnake venom is mostly watery in nature. It consists of numerous enzymes,
\nproteins, aminoacids, etc., Some of the enzymes are proteases, collagenases, arginine
\nester hydrolase, hyaluronidase, phospholipidase, metallo-proteinases, endogenases,
\nautocoids, thrombogenic enzymes, etc., These enzymes also act like toxins on different
\ntissues of the body, and are grouped under neurotoxins, nephrotoxins, hemotoxins,
\ncardiotoxins, cytotoxins etc., resulting in organ dysfunction \/ destruction. Enormous
\nclinical and experimental works have been published on the pathophysiology of snake
\nbite in relation to different species of snakes.
\nThe quality and quantity of enzymes and other clinical constituents vary with
\nspecies and subspecies, and the response of the victims to those substances are also
\nvariable, thus resulting in dissimilar features in different individuals. For example
\nhyaluronidase allows rapid spread of venom through subcutaneous tissues by disrupting
\nmucopolysaccharides, and phospholipase A2 has esterolytic effect on the red blood
\ncell membrane and causes hemolysis. It also promotes muscle necrosis. Thrombogenic enzymes promote formation of weak fi brin clot, which activates plasmin and results
\nin consumptive coagulopathy and hemorrhagic consequences. Venom of some snakes
\ncauses neuromuscular blockade at pre or post synaptic level. In addition to above it
\ncauses endothelial cell damage which results in increased vascular permeability. In
\nshort, snake venom acts on various parts \/ systems \/ organs of the body. Venom also
\ncauses endothelial cell damage which results in increased permeability.
\nSymptoms and signs:
\nAn international expert on snakebite, the late Dr. Alistair Reid of the Liverpool
\nSchool of Tropical Medicine found out that only 10 to 15% of venomous bites end
\nin death. The possibility of survival, even without treatment, is incredibly good in
\n80-90% of cases. One of the reasons for this is that many snakebites are by nonvenomous
\nsnakes. Secondly, a large percentage of venomous snakebites are dry bites
\ni.e., the snake does not always inject venom. Sometimes, it might inject only a tiny
\nquantity of venom. The snake can inject the quantity of venom it wants. This is an
\nentirely voluntary process. Hence, one can never know how much venom was injected
\nexcept by observing the progression of the symptoms. In other words the recovery
\nin snakebite without even treatment is great. Every traditional healer uses this fact
\nto his \/ her advantage and propagates his \/ her own method to treat snakebite viz.,
\nherbal details, \u201csnakestone\u201d or mantra, or plain soda water and most villagers would
\nbe happy to go to him.
\nAlso, every one should remember the systemic action of venom and the extent
\nvaries from one snake to another. Complications and outcome due to snakebite may
\nalso vary from each other and can\u2019t be predicted by any means. Moreover, the status
\nof poisoning cannot be judged by the bite mark, reaction to envenomation, size or the
\ntype of snake. Hence, one has to observe for signs and symptoms which may develop
\nwithin 24 to 48 hours.
\nThe symptoms and signs of Viperine and Elapid envenomation as well as lateonset
\nenvenomation are listed below.
\nGeneral symptoms and signs of Viperine envenomation
\nLocal effects
\n\u2022 Swelling and local pain with or without erythema or discoloration at the site
\nof bite
\n\u2022 Tender enlargement of local lymphnodes as large molecular weight Viper
\nvenom molecules enter the system via the lymphatics.
\n\u2022 Effects due to coagulopathy and hemorrhagic consequences
\n\u2022 Bleeding from the gingival sulci and other orifi ces.<\/p>\n

\u2022 Epistaxis.
\n\u2022 The skin and mucous membranes may show evidence of petechiae, purpura
\nand ecchymoses.
\n\u2022 The passing of reddish or dark-brown urine or declining or no urine output.
\n\u2022 Lateralising neurological symptoms and asymmetrical pupils may be indicative
\nof intra-cranial bleeding.
\n\u2022 Vomiting.
\n\u2022 Acute abdominal tenderness which may suggest gastro-intestinal or retro
\nperitoneal bleeding.
\n\u2022 Hypotension resulting from hypovolaemia or direct vasodilation.
\n\u2022 Low back pain, indicative of early renal failure or retroperitoneal bleeding.
\nOther effects
\n\u2022 Muscle pain indicating rhabdomyolysis.
\n\u2022 Parotid swelling, conjunctival oedema, sub-conjunctival haemorrhage.
\nGeneral symptoms and signs of Elapid envenomation
\nLocal effects
\n\u2022 Swelling and local pain with or without erythema or discoloration at the site of
\nbite (Cobra).
\n\u2022 Local necrosis and \/ or blistering \/ bullae (Cobra).
\nNeurotoxic effects
\n\u2022 Descending paralysis, initially of muscles innervated by the cranial nerves,
\ncommencing with ptosis, diplopia, or ophthalmoplegia. The patient complains
\nof diffi culty in focusing and the eyelids feel heavy. There may be some
\ninvolvement of the senses of taste and smell.
\n\u2022 Problems of vision, breathing and speech.
\n\u2022 Paralysis of jaw and tongue may lead to upper airway obstruction and aspiration
\nof pooled secretions because of the patient\u2019s inability to swallow.
\n\u2022 Numbness around the lips and mouth, progressing to pooling of secretions,
\nbulbar paralysis and respiratory failure.
\n\u2022 Hypoxia due to inadequate ventilation can cause cyanosis, altered sensoriun
\nand coma. This is a life threatening situation and needs urgent intervention.
\n\u2022 Paradoxical respiration, as a result of the intercostal muscles paralysis is a
\nfrequent sign.<\/p>\n

\u2022 Krait bites often present in early morning with paralysis that can be mistaken
\nfor a stroke. Stomach pain which may suggest submucosal haemorrhages in
\nthe stomach.
\nOther effects
\n\u2022 Stomach pain which may suggest submucosal haemorrhages in the stomach
\n(Krait).
\n\u2022 Eye pain and damage due to ejection of venom into the eyes by spitting cobra
\n(as observed in Africa)
\n[If features of renal failure are noted search for other causes \/ mechanisms]
\nLate-onset envenomation
\nThe patient should be kept under close observation for at least 24 hours. Many
\nspecies, particularly the Krait and the Hump-nosed pit viper are known for the length
\nof time it can take for symptoms to manifest. Often this can take between 6 to 12 hours.
\nLate onset envenoming is a well documented occurrence. This is also particularly
\npertinent at the start of the rainy season when snakes generally give birth to their
\nyoung. Juvenile snakes (young ones), 8-10 inches long, tend to bite the victim lower
\ndown on the foot in the hard tissue area, and thus any signs of envenomation can take
\nmuch longer to appear.
\nOverlapping symptoms and signs
\nRussells Viper envenomation can also manifest with neurotoxic features. This can
\nsometimes cause confusion and further work is necessary to establish how wide this
\nmight be. Development of neurotoxic features in Russells Viper bite are believed to be
\npre synaptic or Krait like in nature. It is for this reason that a doubt is expressed over
\nthe response of both species to Neostigmine. Clinical aspects and therapeutic response
\nin relation to some of the poisonous snakes in India is provided in Table no. 3<\/p>\n\n\n\n\n\n\n\n\n\n
Feature<\/strong><\/span><\/td>\nCobras<\/strong><\/span><\/td>\nKraits<\/strong><\/span><\/td>\nRussells Viper<\/strong><\/span><\/td>\nSaw Scaled Viper<\/strong><\/span><\/td>\nHump Nosed Viper<\/strong><\/span><\/td>\n<\/tr>\n
Local Pain\/ Tissue Damage<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\n<\/tr>\n
Ptosis\/ Neurological Signs<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES!<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\n<\/tr>\n
Haemostatic abnormalities<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nNO!<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\n<\/tr>\n
Renal Complications<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nNO<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\n<\/tr>\n
Response to Neostigmine<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nNO?<\/strong><\/span><\/td>\nNO?<\/strong><\/span><\/td>\nNOT Applicable
\n<\/strong><\/span><\/td>\n		NOT Applicable
\n<\/strong><\/span><\/td>\n<\/tr>\n
Response to ASV<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nYES<\/strong><\/span><\/td>\nNO<\/strong><\/span>
\n
\n<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

[* If features of renal failure are noted search for other causes \/ mechanisms]
\nSea snakes:
\nSea snake bites are reported rarely among fi shermen and \/ or their family members
\nliving in the seashore area as well as among those who walk on the seashore. To begin
\nwith there may be local pain which may be insignifi cat which appears within 60 to 90
\nminutes. There may not be obvious local swelling. Systemic manifestations noticed
\namong poisonous sea snake bite are neurological involvement, severe muscle pain,
\nrigidity, renal failure, hyperkalemia and fi nally cardiac arrest.
\nCriteria for diagnosis
\nAn approach to snakebite is provided in Annexures VIII and IX. The criteria to
\ndiagnose poisonous snakebite in a given clinical setting are:
\na. Systemic envenomation in the form of coagulopathy and neurotoxicity.
\nb. Local envenomation (Table no: 4). Features of local envenomation – are grouped
\nunder the mneumonic \u201cPONDS\u201d.
\nTable No :4 : Details of local envenomation
\n\u2022 Pain- pain at the site of bite, swelling and regional lymphnode
\n\u2022 Oozing- sero \/ sanguinous oozing from the site of bite
\n\u2022 Node- development of an enlarged tender lymphnode draining the bitten
\nlimb
\n\u2022 Discoloration- discoloration at the site of bite
\n\u2022 Swelling \u2013 swelling is seen at the site of the bites on the digits (toes and
\nespecially fi ngers); local swelling develops in more than half of the bitten
\nlimb immediately (in the absence of the tourniquet) and swelling extends
\nrapidly beyond the site of bite (eg. beyond the wrist or ankle within a few
\nhours of bites on the hands or feet)<\/p>\n

Complications and Outcome
\nComplications in snake envenomation are due to the heterogenous composition of
\nthe venom. In addition the quantity and quality of the venom and the response of the
\nindividual to the components of venom infl uence the clinical course, complications
\nand outcome. The complications of venom are observed in various systems viz., the
\nhematological, vascular, renal, respiratory, cardiovascular, endocrine, gastrointestinal,
\nmuscular and dermatological system.
\nIn addition to the anti snake venom, the envenomed individual requires supportive
\ntreatment for the complications arising out of snakebite as well as the consequences of
\nthe complication. One must also remember to look for complications developing after
\ninfusion of Inj.anti snake venom and get prepared to treat them also.
\nThe outcome of snakebite depends upon amount of envenomation, bite to needle
\ntime, individual\u2019s response to envenomation, the complications that develop following
\nsnakebite and response to treatment. Till the patient has recovered, one cannot predict
\nthe complications and outcome.<\/p>\n

Investigations
\n20 Minutes Whole Blood Clotting Test (20WBCT)
\nThe 20 Minutes Whole Blood Clotting Test (20WBCT) is considered as the most
\nreliable test for coagulation and can be carried out at the bedside without specialised
\ntraining. It can also be carried out in the most basic settings. It is signifi cantly superior
\nto the \u2018capillary tube\u2019 method of establishing clotting capability and is the preferred
\nmethod of choice in snakebite. The advantages, requirements and procedure for
\n20 WBCT are provided in in Table no: 5<\/p>\n

Table No. 5: 20 Minutes Whole Blood Clotting Test (20WBCT)<\/p>\n

Advantages
\n\u2022 The most
\nreliable test of
\ncoagulation.
\n\u2022 Can be carried
\nout, at the
\nbedside.
\n\u2022 Does not
\nrequire
\nspecialised
\ntraining.<\/p>\n

Requirements<\/p>\n

Dry glass test tube
\n(clean and new)
\n\u2022 2ml disposable
\nsyringe
\n\u2022 Cotton
\n\u2022 Antiseptic solution
\n\u2022 Clean gloves (one
\npair)
\n\u2022 (The test tube
\nmust not have
\nbeen washed with
\ndetergent, as this
\nwill inhibit the
\ncontact element
\nof the clotting
\nmechanism)<\/p>\n

Procedure<\/p>\n

Wash hands with soap and water.
\n\u2022 Wear the gloves
\n\u2022 Collect 2ml blood from the
\nperipheral vein of the unaffected
\nlimb
\n\u2022 Remove the needle and pour the
\nblood along the walls of the test
\ntube
\n\u2022 Keep the test tube untouched and
\nunshaken in a safe place near
\nthe patient\u2019s bedside at ambient
\ntemperature for 20 minutes
\n\u2022 Note the time
\n\u2022 After 20 minutes the test tube is
\ngently tilted and if the blood is
\nstill liquid then the patient has
\nincoagulable blood.<\/p>\n

If the 20WBCT is normal in a suspected case of poisonous snakebites, the test
\nshould be carried out every 30 minutes from admission for three hours and then hourly
\nafter that. If incoagulable blood is discovered, the 6 hourly cycle will then be adopted
\nto test for the requirement of repeat doses of ASV. This is due to the inability of the
\nliver to replace clotting factors under 6 hrs.
\nOther Useful Tests:
\n\u2022 Clinical test:
\n– PR \/ BP \/ RR \/ Postural Blood Pressure
\n\u2022 Laboratory studies:
\n– Haemoglobin \/ PCV \/ Platelet Count\/ PT \/ APTT \/ FDP \/ D-Dimer
\n– Peripheral Smear \/ Blood grouping \/ Rh typing
\n– Urine Tests for Proteinuria \/ RBC \/ Haemoglobinuria \/ Myoglobinuria
\n– Biochemistry for Serum Creatinine \/ Urea \/ Electrolytes \/ Oxygen Saturation
\n\u2022 Imaging studies :
\n– X-Ray Chest \/ CT \/ Ultrasound (whenever required)
\n\u2022 Others
\n– Electrocardiogram
\n– Special investigations depending upon clinical status.
\n– Ocular fundus examination<\/p>\n","protected":false},"excerpt":{"rendered":"

Pathophysiology: Snake venom is mostly watery in nature. It consists of numerous enzymes, proteins, aminoacids, etc., Some of the enzymes are proteases, collagenases, arginine ester hydrolase, hyaluronidase, phospholipidase, metallo-proteinases, endogenases, autocoids, thrombogenic enzymes, etc., These enzymes also act like toxins on different tissues of the body, and are grouped under neurotoxins, nephrotoxins, hemotoxins, cardiotoxins, cytotoxins […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":21,"menu_order":2,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-29","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/pages\/29","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/comments?post=29"}],"version-history":[{"count":0,"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/pages\/29\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/pages\/21"}],"wp:attachment":[{"href":"https:\/\/doctorbruno.info\/snake-bite-scorpion-sting-protocol\/wp-json\/wp\/v2\/media?parent=29"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}