1. Environmental Emergencies Dr Simon Smith Bendigo ED Conference September 3 rd 2014

2. To Be Discussed Electrocution Injuries Lightning Strike Hyperthermia Hypothermia Submersion Injuries Other – Altitude Medicine – Diving Medicine

3. Electricity To understand the mechanism and injuries sustained of electrical injuries, the underlying basic physics should be understood GRRRRROOOOAAAN

4. Basic Physics Current (Amps)= Voltage(V)/Resistance(Ohms) I=V/R Resistance Influenced by – moisture, type of tissue Example – Moist skin, I=240V/1000 Ohms =240mA – Dry thick skin, I=240V/100000 Ohms = 2.4mA

5. Current 1 mA 10 mA 50 mA 100 mA Mild sensation Muscular paralysis Shock, difficulties breathing Respiratory paralysis Cardiac arrest

6. Factors Determining Injury Type of circuit – DC v AC Duration Resistance of tissues Voltage Amperage Pathway of Current

7. Electric Shock Clinical effects – Cardiac – VF common cause of arrest – Burns – worse than they look – Nervous system – Renal – ARF secondary to myoglobin – Vascular – thrombosis and haemorrhage – Musculoskeletal – fractures, dislocations, other

8. Electric Shock Management Investigations ECG Imaging (if indicated) Bloods ( CK/CUE/FBE)

9. Lightning Strike

11. 100,000,000 volts Duration of milliseconds Types of strike – Direct – Side – step

12. Clinically Cardiac Cutaneous Vascular neurological

14. Differences from electric shock Reverse triage for disaster scenario Deep burns rare Cardiac arrest – usually asystole Anecdotally - ? Longer CPR

15. Hyperthermia

17. Spectrum of heat related illness – Heat stroke – Heat exhaustion – Heat cramps

18. Heat Stroke Definition – Core body temp > 40 degrees – CNS abnormalities – delerium, seizure, coma Types – Classical – exertional

19. Heat Stroke Risk Factors Environment Age Physical Medical medications

20. Clinical Effects Neurological Cardiovascular Rhabdomyalysis Renal Haematological

21. Investigations Bloods – CUE/CK/LFT/FBE/ABG ECG Imaging

22. Management Rapid cooling – If undertaken early, reduction in mortality – Multiple methods Evaporative cooling Ice water immersion Other techniques – Ice packs, lavage, body cooling units Support of organ function Exclude differential diagnosis

23. Cooling Methods methodAdvantagesdisadvantages EvaporativeSimple, effective, non-invasiveShivering Difficult to maintain electrodes ImmersionNon-invasive, effectiveShivering, poorly tolerated Difficult to maintain Strategic ice packsNon-invasive, available Can combine with other technique Decreased efficacy Poorly tolerated Cold gastric lavageInvasive, intensive

24. Cooling Methods methodRate of cooling Ice packs to groin/axilla/neck0.1 (degree per minute) Evaporative cooling0.31 Lavage (gastric / peritoneal)0.56

25. Ongoing Management Avoid overshoot – hypothermia Manage complications – Airway – intubation – Circulation – fluid, inotropes – Renal failure – DIC Additional therapy – Decrease shivering – diazepam, chlorpromazine

26. Hypothermia

27. Defined as core temperature < 35 degrees temperatureclinicallycardiacneurological 32-35Maximum shiveringNormal blood pressureAmnesia, dysarthria ataxia 28-32Shivering extinguished poikilothermia Atrial fibrillation Susceptible to VF Stupor Pupils dilated at 29 <28Major acid/base issue Pulmonary oedema Max risk of VF at 22 Asystole at 18 degrees Cardiac output 45% Loss of reflexes Flat EEG

28. Hypothermia - causes Environmental Drug induced Sepsis Iatrogenic Dermal disease Hypothalamic and CNS dysfunction

29. Hypothermia Management General measures – Remove clothing Warming – Passive external (mild hypothermia) – Active external (moderate hypothermia) Core temperature afterdrop – Active core re-warming (severe hypothermia) O2 / IV fluid / lavage

30. Hypothermia - Investigations Bloods – CUE / glucose / CK / coags / ABG ECG – Bradycardia – Atrial fibrillation – Heart block – Osborne Wave – VF

31. Osborn Wave

32. Hypothermia - Differences in ALS Warming core component Below 30 degrees – Only one attempt at shock – Only one dose of drug ? Delay to CPR

33. Hypothermia - Controversies Afterdrop -?significance Limited handling Intubation Prolonged CPR

34. Submersion Injuries

35. Submersion Injury drowningDeath by suffocation after submersion in liquid Used if death within 24 hours Near drowningSurvival for > 24 hours post submersion Secondary drowningDeath >24 hours post submersion

36. Epidemiology Second most common cause of death in children Most deaths – teenage boys, toddlers Boys 5x more likely than girls Alcohol major risk factor in adolescence

37. Pathophysiology Timeline – Panic, struggling, breath holding, hyperventilation – Aspiration (85%) or laryngospasm (15%) – Hypoxia – Loss of consciousness – Pulmonary oedema

38. Important Points on History Estimated time of submersion Temperature of water How and when the victim was rescued How soon after rescue respiration resumed What kind of resuscitation was given Consideration of trauma

39. Management Varies according to severity Varying classification systems Simple delineation on GCS – GCS>13 Ix as indicated (may be none), Sx treatment, O2 Observe for 6 hours – GCS<13 Ix may include – CXR / ABG / imaging / etoh Resp support – O2,CPAP,intubation,PEEP,bronchodilator

40. Prognostic Factors Submersion >25 min Resuscitation >25 min VT or VF on ECG Initial GCS<5 or pupils dilated Severe acidosis

41. Altitude Medicine

42. Diving Medicine

43. Marine Evenomations

44. Snake Evenomations