1. Submersion Injuries Richard Dionne MD CCFP-EM Assistant Professor Emergency Medicine Ottawa Hospital-University of Ottawa Assistant Medical Director Ottawa Base Hospital Paramedic Program Fellowship Director EMS & Disaster Medicine April 2 nd, 2008

2. Near Drowning Objectives Understand causal conditions Differentiate between fresh & salt water drownings Identify potential injuries Select appropriate diagnostic & management Consider treatment of hypothermia & trauma

3. Definitions Drowning: –terminal outcome from submersion event Near-drowning: AHA no longer uses Submersion Injuries: – survival, at least temporarily, after suffocation in a liquid medium 3 rd most common cause of accidental death overall, leading cause in < 5 yo ETOH / Drugs often associated

4. Immersion Syndrome Syncope secondary to cardiac dysrhythmias on sudden contact with water at least 5 o C < body T QT prolongation & massive release of catecholamines plus vagal stimulation =>asystole and VF Resultant LOC leads to drowning

5. Risk Factors Inability to swim (overestimation of capabilities Risk taking behaviour Substance abuse (in >50% of adult drownings) Inadequate supervision (bathtub) Concomitant conditions: trauma, seizure, CVA, cardiac event

6. Pathophysiology Aspiration of 1-3 mL/kg destroys integrity of pulmonary surfactant (  lung compliance) Alveolar collapse, atelectasis, Non-cardiogenic pulmonary edema (ARDS), Intrapulmonary shunting, V/Q mismatch

7. Profound hypoxia Respiratory acidosis, ARDS Cardiovascular collapse Neuronal injury …. Death End Organ Effect

8. Salt vs Fresh Water: Does it Make a Difference? Historically felt to affect electrolytes, fluid shifting, hemolysis Intravascular abnormalities do not occur until aspirated water > 11 mL/kg Most aspirate <4 mL/kg Review of 91 submersion victims, no pt required emergent intervention for electrolyte abN No significant clinical difference between the two!

9. Management of Care Prehospital Emergency Inpatient

10. Prehospital On scene: –Immediate Rescue Breathing (even before out of water)… Heimlich not proven … –Bystander CPR (pulse check 30 sec.) –Consider trauma: C-spine precautions –Remove wet clothing, passive exernal rewarming (Hypothermia!)

11. Emergency Department ABC’s Early airway management Cardiac monitor, CORE (rectal) temp Immediate rewarming (Hypothermia) Passive External Active External Active Internal

12. Inpatient Management Goal: prevent further secondary neurologic injury and minimise end-organ damage.

13. Submersion Injuries Gen: hypothermia, trauma GI: vomiting (swallow >> aspirate) Respiratory: – +’ve pressure ventilation leads to gastric distention, risk of aspiration –Aspiration of particulate contaminants –Hypoxia from direct surfactant effects –ARDS

14. Submersion Injuries CVS: dysrhythmias CNS: initial hypoxic injury or secondary reperfusion injury with resuscitation Renal: ARF due to lactic acidosis, prolonged hypoperfusion, rhabdomyolysis Heme: coagulopathies

15. What Investigations Do You Need? ECG: for dysrhythmias, prolonged QT ABG: any resp signs/symptoms Labs: electrolytes, renal function, CBC, glucose although usually N Screening for ETOH, drugs CXR: may underestimate severity initially

16. Factors Affecting Survival Age Water temperature Duration & degree of hypothermia Diving reflex Resuscitation efforts Prior medical conditions

17. Hypothermia: Good or Bad?? Lowers cerebral metabolic rate, neuroprotective Diving reflex: shunting of blood centrally in response to cold water stimulus Causes bradycardia & apnea, decreased metabolic consumption Prolonged duration of submersion tolerated Cold water speeds development of exhaustion, LOC and dysrhythmias

18. Poor Prognostic Factors > 10 minutes submersion CPR initiated >10 min after rescue Severe acidosis (pH < 7.1) Unreactive pupils GCS = 3 (comatose) Hypothermia in ED ? < 3 yo Need for ongoing CPR Lack of spontaneous movement at 24hrs

19. Who can go home? Asymptomatic on presentation Maintains normal room air sat No CXR or ABG abnormalities …… D/C after 8 hour observation

20. Submersion Injuries: Overview Immediate resuscitative efforts is key! Consider associated trauma, ETOH/drugs Development of pulmonary injury may take time, initial CXR may be normal No clinical difference b/w salt & fresh H 2 O Majority of treatment is supportive, rewarming & not underestimate …Prevention !!! Monitor x 6-8 hr for asymptomatic pt with normal investigations