Snake bites in remote areas

Dr David WilliamsCharles Campbell Toxinology Centre

School of Medicine & Health SciencesUniversity of Papua New Guinea

Department of Pharmacology & TherapeuticsUniversity of Melbourne

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PAPUA NEW GUINEA

Port Moresby

AUSTRALIA

We run nationwide clinical training courses in snakebite management

Photo: Dr Wolfgang Wüster

Photo: Dr Wolfgang Wüster

We teach fundamental clinical skills and basic life-support techniques with active

participant involvement

Photo: Dr Wolfgang Wüster

We are identifying critically placed key rural health workers who are extensively trained in

advanced airway management

Photo: Dr Wolfgang Wüster

Photo: Dr Wolfgang Wüster

Snakebite in remote areas

• Many rural health facilities are not in a position to manage snake bite patients because of a lack of drugs, equipment, skills and specific knowledge

• They can potentially apply good first aid, provide emergency treatment for shock, and if necessary provide supportive care and non-invasive airway management

• In these situations patients will need to be sent to another hospital for definitive treatment

• All health centres should develop and maintain a clear, pre-existing plan for how patients will be transported, and to which hospital they will be sent

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Successful early snakebite management

• Excellent outcomes can be achieved in even the most basic care environments.

• Snakebite can treated in remote locations by nurse practitioners.

• Medical evacuation should not need to be an automatic process.

• Intensive care admission is avoidable.

• Training, education and appropriate basic resources are the basic requirements.

Be prepared for snakebite

• Having a protocol in place that is known to all personnel.

• Stocking adequate appropriate antivenom if possible.• Have an organised emergency room.• If you are going to seek advice from an external

consultant, have their details in a place where anyone can find them.

• Plan early: if evacuation is necessary you should organise it sooner rather than later

Have a protocol in place

• Systematic and sequential investigations.• Immediate assessment of ABC.• Thorough history.• Good clinical examination to demonstrate specific life-

threatening deficits:– Threats to airway and breathing (neurotoxic signs)– Bleeding (seen and unseen)– Other defects (severe cytotoxicity, shock)

• 20WBCT• Be realistic about who to treat and who to refer.

Treatment or Referral

• Need to decide as quickly as possible if it is possible to treat the patient locally, or if they will require referral to hospital elsewhere:– Bites with no signs, or minimal local swelling and no other

signs may not need referral– Bites with extensive local swelling (>50% limb) or very severe

localised swelling (e.g.: fingers/hands/toes/feet), or with bleeding, paralysis should be referred to hospital without delay

• Referrals need to be well planned and consequences carefully considered.

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Key considerations

• There should always be a clear reason for patient referral, and this should be recorded in both the patient’s notes, and in the referral letter.

• Patient transport should not put the patient at additional risk or reduce the level of patient safety

• Referral should be to a facility that provides a higher level of care

• Patients at risk of life-threatening problems such as bleeding, neurotoxicity, shock or renal failure should always be accompanied by medical staff trained in basic emergency life support

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Timing of medical referrals

• A patient who needs referral should be send onward as soon as possible

• Don’t wait for complications to occur!• Specific timing:

– after first aid (immobilisation or PIB) applied– once you have resuscitated Airway, Breathing and Circulation,

in that order, to the best of your ability & resources

• Do not wait until the patient has deteriorated before initiating referral or they may die enroute

• Early referral saves limbs and saves lives!13/04/23 29

Types of transport

• Carried by stretcher• Private vehicles:

– Motorcycles– Cattle-drawn carts– Tractors– Cars and trucks

• Ambulances• Government vehicles• Boats• Aerial retrieval in rare situations

(i.e.: military)

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Criteria for referral (1)

• Does the health facility have the resources to treat the patient?:– Essential drugs and medical supplies– Equipment (diagnostic, treatment delivery and life support)– Staff with the necessary knowledge and experience to

provide treatment and make informed decisions

• If the answer to any of these points is no, then early referral to a better facility should be a priority once the patient is stabilised

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Criteria for referral (2)

• Will referral of the patient result in a significant improvement in patient care, or provide access to an essential, but locally unavailable medical service?– If the answer is yes, then referral is appropriate– If the answer is no, reconsider referral of this patient

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Patient safety (1)

• Will the safety of the patient be compromised by attempting to transport them to another facility?:– Is the patient clinically unstable?

• Is there severe bleeding?• Is the patient shocked?• Does the patient has airway and breathing problems?

– Will it be possible to provide emergency treatment to the patient in the type of transport that is available?

• If not, are there any alternatives available?

– Are the road conditions suitable to ensure that the patient can reach the referral hospital?

• Is there a risk of the vehicle getting bogged or stopped by floods13/04/23 35

Patient safety (2)

• A clinically unstable patient should not be moved until the immediate risk has reduced:– Shocked patients or those with severe bleeding require

adequate fluid resuscitation to maintain cerebral perfusion (i.e: a minimum BP of 80/60)

– Airway and/or breathing support for paralysed patients

• Obtain qualified medical advice from an expert– Consider the need to have the patient retrieved by

ambulance and a medical team

• Is it safer to delay referral until the patient is more stable, or is it a case of ‘now or never’?

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Stabilising shocked or bleeding patients

• Patients bitten by some species of pit viper may present with hypovolaemia and vasodilatation leading to hypotension and shock

• This may be due to migration of circulating fluid into the swollen limb, or may be the result of external or internal haemorrhage

• Emergency resuscitation with crystalloid or colloid should be carried out.

• Endeavour to maintain a minimum blood pressure of 80/60 mmHg

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Stabilising shocked or bleeding patients

• If antivenom is available it should be given without delay to neutralise circulating toxins that contribute to coagulopathy

• Be careful not to overload the patient with fluids as this may lead to additional complications

• Patients in whom increased capillary permeability is suspected may benefit from administration of i.v.i. dopamine (2.5-5.0 μg/kg/min)

• When stable transport the patient while continuing to monitor bleeding and blood pressure, and with adequate intravenous fluid to continue treatment

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Treatment of Shock (1)

• Specific treatments– Assess for & treat Airway or Breathing problem– Obtain good, large-bore IV access, if not available– 20ml/kg crystalloid, saline or Ringer’s, as fast as possible

– eg. a 50kg person should be given 20x50=1000ml– eg. a 15kg child should be given 20x15=300ml

– Repeat the vital signs frequently, e.g. every 10 minutes– Give high flow oxygen (6-15l/min)– Repeat the infusion if the patient is still unstable– Give antivenom, if available

• Consider whole blood replacement after 40ml/kg of crystalloid, if there is heavy bleeding & no antivenom is available

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Treatment of Shock (2)

• Specific Treatments– Treat obvious cause

• If cause is antivenom reaction (adrenaline, promethazine, hydrocortisone)

• If septic shock, give broad spectrum IV antibiotics

– Atropine 5-20mcg/kg for bradycardia– Consider dopamine (5-20mcg/kg/min)

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Treatment of Shock (3)

• Intravenous access– Try to be successful as soon as possible– As large an IV cannula as possible– Ideally 2 lines– Use femoral, long saphenous or external jugular if necessary– Avoid causing another site of bleeding– Intraosseus, especially in child, if no IV access in first few

minutes

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Patients with airway/breathing problems

• Protect the airway!– Posture, chin lift or head tilt to

improve air entry– Guedel’s airway devices– Oropharyngeal airways– Laryngeal masks– Endotracheal intubation

• Support breathing– Supplementary oxygen– Ambu Bag ventilation– Mechanical ventilation

• Transport only if the airway is secure and breathing can be supported by trained staff

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Mask fits on patient’s face over bridge of nose and

under the mouth

Don’t compress the patient’s eyes

Bag and mask

Broad end fits under patient’s mouth

Pointed end over the patient’s nose

Inflatable cushion

15 mm connector

Positioning of the MaskWatch the position of the mask regarding the eyes

1. Place mask onto face & spread your fingers as shown

2. Place your fingers under the jaw grasping mandibular margins- don’t push into the soft tissues

3. Double handed approach

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Complications of BMV

• Ineffective oxygenation: hypoxia• Gastric inflation• Aspiration• Worsening of facial #s• Compression of eyeballs

– retinal detachment

• Compression of facial and infraorbital nerves• Complications related to oro-pharyngeal or

nasopharyngeal airways used

Laryngeal Masks

LMA SupremeLMA Supreme Elliptical airway tube Elliptical airway tube prevents kinkingprevents kinking

Tougher tip prevents folding Tougher tip prevents folding during insertion.during insertion.

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Gastric drainage tubeGastric drainage tube

Bite blockBite block

Securing bar, should be at lipsSecuring bar, should be at lips

Ventilating tubeVentilating tube

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Epiglottic fins prevent epiglottisEpiglottic fins prevent epiglottisfrom entering airwayfrom entering airway

Gastric drainage tubeGastric drainage tube

Cuff must be fully deflated to prevent Cuff must be fully deflated to prevent bulging here during insertionbulging here during insertion

Reinforced tip Reinforced tip prevents fold overprevents fold over

Laryngeal Masks

• Advantages:– Easy to insert, and it technique can easily be taught to non-

doctors.– Better oxygenation than with use of bag/mask alone.– Rescue airway

• Disadvantages:– Gastric inflation if not correctly positioned– Aspiration risk not 100% removed– Cuff pressure need to be monitored– Risk of pharyngeal trauma is forcefully inserted including risk

of hypoglossal nerve injury

Why and when to insert LMA

• Patients who can tolerate a Guedel airway will tolerate an LMA equally well

• LMA may not protect against aspiration but very few cases of aspiration have been recorded– but better protection than BMV alone– increasing use in first aid trauma

• Easier to insert than endotracheal tube– Don’t need laryngoscope

• Can insert while ECM being conducted– Difficult to intubate in these conditions

Excessive oral secretions

• Often a serious, life-threatening complication of neurotoxic snake bites (e.g.: mamba bites)

• Careful, regular suctioning of the airways is essential:– Hand-held or foot-operated suction pumps available– Ignored, death from airway obstruction may be very rapid

• Ancillary drug treatment with atropine (0.6 mg) every 3-4 hours can help to reduce secretion levels

• Position the patient appropriately:– Recovery position on their side– NEVER transport a neurotoxic patient in supine position

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Preparation for patient referral (1)

• Organise transport:– What type of transport is necessary? Is it available? – If not, what are the alternatives?– Basics: vehicle with fuel, driver, spare tyre, mobile phone– Check that road conditions & weather appropriate– Who will accompany the patient?

• Prepare the patient:– First aid measures in place and patient stable as possible– If antivenom is available, administer before departure– airway & breathing managed appropriately– circulation: nil by mouth, IV line secured well, IV fluids

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Preparation for patient referral (2)

• Ensure staff are ready:– Adequately trained & experienced to manage circulation

problems, airway and breathing enroute– Do they have personal items & money ready– Are their shifts covered– Have arrangements been made for their return– if you absolutely cannot send a staff member with the patient,

reconsider the need to refer the patient, or consider waiting until you can send a staff member

• Drugs & equipment ready in box/bag– Adequate i.v. fluids, sphygmanomometer, stethoscope– Airway equipment, oxygen, suction pump & attachments– Flashlight or lantern (for night transfers)

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Preparation for patient referral (3)

• Communication complete:– Consult the referral hospital for advice before you send the

patient onwards– Ensure that they have the capacity and resources to be able

to accept the patient– Once referral is confirmed, prepare documentation

• Documentation:– referral letter– copy of notes, snakebite admission sheet or snakebite

observation sheet– Chest X-Ray if available, especially for intubated patients

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Referral letters

• In addition to clinical notes that are sent with patient, send a referral letter that includes:– Date & time– Name of referring person, referring facility– Name of the doctor the patient is being referred to– Telephone call details, telephone number for feedback– Name and details of patient– Summary of history (bite history, symptoms and signs),

examination, results and times of investigations– Any information about type of snake suspected– Summary of treatments given, timing & response– Details of improvement or deterioration – Reasons for referral

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Patient care during transport

• Position the patient in a sitting position if they have no airway or breathing problems

• If the airway is compromised, lay them on their side, with the head supported and tilted slightly downwards to prevent aspiration of mucus/saliva

• Hang the I.V. fluid bag and monitor it • Staff member should remain with the patient so that

emergency treatment can be given if needed• If no staff member accompanies the patient, and the

referral is urgent, then a family member must be taught to provide basic life support.

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Summary (1)

• Have a clear reason for referral of the patient (i.e.: to obtain antivenom treatment, or gain access to a ventilator)

• Be sure that referral will result in an improvement in care for the patient, and that the transport of the patient does not place them at greater risk

• If referral is necessary, do it as soon as possible• Choose appropriate transport• Ensure that the patient meets the criteria for referral to

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Summary (2)

• Do not refer the patient until they are clinically stable in terms of airway, breathing and circulation

• Be well prepared:– Organise transport– Prepare the patient– Ensure staff are ready to travel with patient– Assemble necessary drugs and equipment– Communicate with the referral hospital and prepare the

documentation

• Care for the patient during transport

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