major envenomation

Clinical Toxicology & Pharmacology, Newcastle Mater Misericordiae Hospital

Major envenomationMajor envenomation

Hunter Area Toxicology Service


PresentationPresentation

56yo male school teacher Major depression for 6 months

– of work for one term– on citalopram 20mg tds

Reflux oesophagitis – laparoscopic fundoplication


Christmas Day 1998Christmas Day 1998

Carrying LPG bottle out to barbecue At 0950 stepped on something soft

which moved Looked down to see a “brown” snake

~ 2 feet long Chased snake out of yard to protect the

grandchildren Wife persuaded him to sit down


First–aidFirst–aid

Bite seen on dorsum of R second toe Tourniquet applied to forefoot at 1010 Son drove him to nearest hospital At 1030 father complained of chest

tightness and difficulty breathing By 1035 father unconscious in car Arrived at ED at 1037


On arrivalOn arrival

1037– Semi–conscious, GCS 6– PR 64, BP 131/77, RR 36 shallow– Bloods taken

1048– Given 1 ampoule brown snake antivenom– Decreased level of consciousness– Decreasing respiration– Monitor showed ST elevation


In EmergencyIn Emergency

1052– Intubated with atropine, midazolam,

suxamethonium– IDC inserted– Given 1 ampoule brown snake antivenom– Urine and bite site tested with VDK

1100 – Monitor showed asystole


In cardiac arrestIn cardiac arrest

1100– CPR commenced– Adrenaline 1mg x 2– Atropine 600 mcg

1108– Femoral output– Sinus rhythm– PR 123, BP 78/35


Post cardiac arrestPost cardiac arrest

1117– PR 142, BP 201/125– Urine and bite site VDK negative– Initial coagulation studies

Blood clotted in coagulation tubes


RetrievalRetrieval

1145– Repeat coagulation studies

PT >50 s aPTT > 200 s

– Given 1 bag FFP 1200

– Retrieval team transport to NMMH– Given 2 ampoules brown snake

antivenom en route


Coagulation studiesCoagulation studies

Time (h) 0.7 1.7 4.7 7.8 10.7 13.9 22.2

PT (10–13 s) * >50 >180 >60 32 17 13

aPTT (22–35 s) * >200 >120 75 47 34 32

TCT (12–16 s) >60 >60 >60 >60

Fib (2.0–4.0 G/L) 0.0 0.0 1.4 3.2 6.4 1.4

XDP (<0.25 mg/L) >1.6 >1.6 >1.6

PLT (150–400 x 109/L) 14 368 144 125 108

Antivenom † † † † † † † † † †


ComplicationsComplications

Chest infection Left ventricular failure/pulmonary

oedema Confusion/delirium/memory deficit


Chest infectionChest infection

Eight hours post envenomation– Febrile 38.5° – Purulent material aspirated from

endotracheal tube– Started on

ampicillin metronidazole gentamicin


Pulmonary oedemaPulmonary oedema

Days 2–4– Pulmonary oedema requiring CPAP– Placed on

ACE inhibitor diuretic therapy

Day 5– Echocardiogram


Muscle enzymesMuscle enzymes

Time (d) 0 1 2 3 4 5

CK (1–185 U/L) 204 827 2866 2120 902 452


Muscle enzymesMuscle enzymes

Time (d) 0 1 2 3 4 5

CK (1–185 U/L) 204 827 2866 2120 902 452

Troponin I* 9.3 – 16.7 – 4.9 2.7

*Apparently healthy individuals <0.4 ng/mL Reference range <1.0 ng/mL Diagnostic of AMI 2.0 ng/mL


ConfusionConfusion

Extubation was delayed due to a marked confusional state evident even while on the ventilator

Delirium persisted for several days and became a significant management problem


SPECT brain scanSPECT brain scan


Neuropsychiatric Neuropsychiatric assessmentassessment

Performed at 6 weeks post envenomation

Wechsler Adult Intelligence Scale Revised (Australia)

Wechsler Memory Scale (Form 1) Rey Auditory Verbal Learning Test Rey Complex Figure Trail Making Test A and B


ResultsResults

WAIS–R– Verbal IQ – 124– Performance IQ – 99– Full scale IQ – 115

5–digits forward, 4–digits backwards Rey Complex Figure

– Copy – above average– Repeat (3 minutes) – below average


ResultsResults

Trail making A – 90+ percentile Trail making B – 25 percentile Memory quotient – 132

– Immediate recall very good– Delayed recall (30 min)

Structured information – very good Unstructured information – good Designs – poor

major envenomation

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