Updates in Clinical ToxicologyEmerging Trends in Emergency Medicine 2012-13
Introduction• Welcome
• CGD – Toxicology 20-40 mins
• My Background• Emergency Medicine• 6 months as Toxicology Registrar in 2010
• Disclosures• None to declare
Learning Objectives
•Aims and Learning Objectives Topics
Emerging Therapies in Toxicology Emerging Illicit Drugs Updates in Toxinology
Approach Case based approach Interactive session Discussion of emerging topics in Toxicology
* There is emerging evidence in the areas discussed but an absence of Randomised Control Trials (RCTs)
Risk Assessment Based Approach to Poisonings
Risk Assessment
• (1) Drug* taken, form, route and dose ▫Defined Daily Dose▫Threshold for Toxicity
• (2) Time since the Ingestion • (3) Progress and Clinical Features• (4) Patient Specific Factors
▫Age▫Weight▫Past Medical History
•Resources – CIAP, Toxinz, Handbooks, Poisons
Toxicology in Retrieval
•Common Secondary Transfer•3/50 for me•Data from recent months….
- High Dose Insulin- Intralipid Emulsion (ILE)- Methylene Blue
Case 1
•Cassie •17 years old, no medical history•From Parkes (rural NSW)•Living with her parents and grandma•After a fight with her mother at dinner she
stormed out stating ‘I hate you all’ – 1 hour later she tells her mother she has taken ‘Gran’s pills’
•Mum tearfully calls an Ambulance and she is brought to the local rural Emergency Department with single weekend coverage
Parkes
Case 1 - Cassie
•On arrival in Emergency she states regret at taking the tablets and wants to go home
•Risk assessment▫2 hours ago she took 2 full blisters (24) of
Verapamil▫The tablets were Slow release (240mg)▫She also took 7 Panadol (5oomg)
• Is this a concerning overdose?•What do we expect to happen?
Progress
•Cassie initially has normal observations (BP 121/70)
•Activated Charcoal (50g) is given •Routine bloods are taken from the patient•On advice from poisons information IV fluids are
started and she is monitored. •A discussion in regards to W.B.I. is undertaken
and it is decided against
Progress 2•The patient is persuaded to stay in hospital•After 4 hours of observation she feels light headed
and nauseous. She has had 20ml/kg of fluid •Her blood pressure quickly drops to 70/40
(confirmed by manual readings)•Her heart rate is now 45/min and despite further
fluids, IV calcium, atropine and glucagon she develops evidence of cardiac failure…
•Now Retrieval Rescue 23 is tasked to get patient
High Dose Insulin Therapy•High-dose insulin euglycemic therapy (HIET)•High-dose insulin therapy with IV glucose
▫Emerging as an effective treatment for severe beta-blocker & calcium channel-blocker poisoning
•Animal data and case reports demonstrate that high-dose insulin (1-10 U/kg/hour) is a superior to standard treatment* in terms of safety and survival in both beta-blocker and calcium-channel blocker poisoning**.
▫S
Kearns et al – Free at http://emcrit.org/wp-content/uploads/ccb.pdf
Local Case Reports
Case 2
•John•79 year old •Presenting to hospital following a fall on
the front porch of his house•He was unable to get up afterwards and
has an obvious deformity of his right leg
Analgesia
•John receives Morphine and Paracetamol IV but still has persistent pain
•The local locum places a femoral block using Marcaine® (Bupivicaine) 20mls with a landmark technique with aspiration every 5mls infiltrated
•A few moments later the patient becomes unresponsive and CPR is started
•The patient’s rhythm is Asystole
Intralipid Emulsion (ILE)•Intralipid is emerging as a first line
therapy for treating the cardiotoxic effects of Local Anaesthetic toxicity and other refractory emergencies
•First described in the 1990s •Data emerging for LA and TCA from
▫Human Case Series▫Animal Data
Intralipid
•Oil and Water Micro Emulsion•Derived from Soya Bean•pH 8.0
•How does it work?▫(1) Lipid Sink
Redistribution**▫(2) Effects on channels
Sodium Channels Calcium Channels
▫(3) Metabolotropic
How to give…
Intralipid Emulsion (ILE)
Intralipid Emulsion (ILE)
Methylene Blue – EAPCCT Abstract
Summary
•Risk assessment is the mainstay of good management of toxicological emergencies
•New therapies are emerging and awareness of these is useful
•These new therapies should be used in the context of advice from a toxicologist and reserved in the main for refractory cases
- Quetiapine - The Synthetic Cannabinoids
Case 3
•Richard is a 41 year old man•History of Schizophrenia managed with
“Seroquel®”•Treated in the community
Case 3
•Richard presents to his GP in Warren (NSW) stating he has taken extra tablets ‘to help him sleep’ but is now worried he has taken too many!
•An ambulance is called after he reveals he has taken 40 x 200mg tablets (a total of 8g) today
•On route he is tachycardic (120) and drowsy but opens his eyes to speech and obeys commands
•Where is Warren?•What is your risk assessment?
Warren
Risk Assessment•(1) Drug* taken, form, route and dose
▫Defined Daily Dose▫Threshold for Toxicity
•(2) Time since the Ingestion • (3) Progress and Clinical Features•(4) Patient Specific Factors
▫Age▫Weight▫Past Medical History
On arrival at Warren Hospital
Quetiapine (Seroquel®)
Emerging as the number 1 toxicological cause of ICU admission in Australia
Adverse Effects
•Tachycardia (common)•Reduced Level of Consciousness (variable) •Delirium (masked)•Coma (dose dependent)
▫Common in overdoses > 3 grams•Respiratory Depression•Hypotension•ECG changes include prolonged QT
▫Arrhythmias are described but are unusual
The ECG of Quetiapine overdose
ECG QT interval
Case 4
•Raymond is a 39 year old•He doesn’t normally take drugs•However he accepted the offer of trying a
‘new’ drug at a party•After a short time Raymond became
agitated and appeared to be disorientated•An ambulance was called and he arrives
at your ED being held down by police and paramedics
K2 Spice – Synthetic Drug
•Potent Cannabinoid▫Multiple Formulations
•Reports of Seizures and Psychosis at increased rates compared to organic Marijuana
•Risk of seizures•Risk assessment should predict a higher
likelihood of adverse outcomes and a longer duration of observation in the ED
•Treatment is primarily supportive
K2 Spice
‘New’ Drugs
‘New’ Drugs
Summary
- Snake antivenom use - what has changed in recent years? - Trends in Red-back spider antivenom use
Case 5
Jason - 13 years old•Playing cricket•While retrieving the ball stood on a ‘twig’ •He ran back to the field complaining of pain•A few minutes later he collapsed and is taken
to hospital by ambulance•On the way to hospital he develops epistaxis
and bleeding from the gums
•What is the most likely diagnosis?
Australian Snakes *Brown Snake (pictured) – A common snake,
can be aggressive Causes the most fatalities due to Coagulopathy
*Death Adder *Tiger Snake *(Red Bellied) Black Snake Mulga & Collett’s Snake *Taipan - reclusive hunter and therefore has
minimal contact with humans. Bites are therefore uncommon. This snake having the most potent venom (LD50) of all snakes
*Sea Snake
Envenomation Summary COAGULOPATHY (VICC, AC) and MAHA LOCAL EFFECTS MYOTOXICITY RENAL FAILURE NEUROTOXICITY
Snake Bite - Updates
•Recent years have seen changes in recommendations:▫Antivenom
Cross over Quantity Indications for antivenom Effectiveness of antivenom Use of the Snake VDK
▫Snake Coagulopathy FFP and antivenom
▫When to Discharge?
Antivenom Dosing
Antivenom – early 2000s
Antivenom Effectiveness
Discharge
Summary
•PIB•PIB removal in a monitored setting•VDK•Antivenom use•FFP
Case 5
•A young mother presents in distress after being bitten by a spider in a shoe
•She has severe leg pain, nausea and has noticed sweating on both legs as well as ‘goose-bumps’ at the site of the bite
•Her confident husband identifies the spider as a Redback and has brought the ‘specimen’ into hospital (alive) in a glass jar
Spider Bite – Redback
•Common presentation•Clinical Syndrome
▫Pain +▫Sweating▫Piloerection
Redback Spider Bite
Clinical Effects
Local andRegional
NB – ThereMay be no ‘History’ ofSpider Bite
SystemicEffects
Local PainRadiating Pain
PiloerectionLocal Sweating
NauseaVomiting
HeadachesLethargy
Remote PainAgitation
HypertensionNeurological
Spider Bite – Redback
Redback Antivenom
•Historically there has been a low threshold for use
•Now Controversial
Redback Antivenom
IM Antivenom
Summary and Future Directions•Provisional results of the FFP and RAVE II
study are imminently pending
•A single vial of antivenom is sufficient for the treatment of snake envenomation
•Analgesia is the mainstay of treatment for redback spider bite.
Other Emerging Topics (Brief Discussion if Time)
•New Anticoagulants•Decontamination and WBI•Naloxone•Sulphonyureas
Questions and Discussion
Top Related