Submersion Injuries

1. Submersion Injuries Richard Dionne MD CCFP-EM Assistant Professor Emergency Medicine - Ottawa Hospital-University of Ottawa Associate Medical Director - Regional Paramedic Program for Eastern Ontario Fellowship Director EMS & Disaster Medicine April 1st , 2010

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. Diving Emergency?

4. 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 • 3rd most common cause of accidental death overall, leading cause in < 5 yo • ETOH / Drugs often associated

5. Risk Factors • Inability to swim (overestimation of capabilities) • Risk taking behaviour • Inadequate supervision (bathtub, pools) • Co morbidity: trauma, seizure, CVA, cardiac

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

9. 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!

10. Submersion Injuries Fresh waterSalt water No difference  Surfactant is destroyed  Alveolar instability  Atelectasis &  Compliance & Bronchospasm  V/Q mismatch  Hypoxia

11. Case • 18 yo male • Boating with friends, “3 beers” • Fell off boat, submersion x 3 min • Brought to boat by friends, rescue breathing started immediately

12. What are the potential problems this pt may have? • What is your immediate management? • What investigations will you order? • What is his prognosis? • Which victims of submersion can I discharge?

13. Management of Care • Prehospital • Emergency • Inpatient

14. 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 external rewarming (Hypothermia!)

15. Emergency Department • ABC’s • Early airway management • Monitor: • cardiac, CORE T °(rectal) • Rewarming • Passive External • Active External • Active Internal

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

17. 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

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

19. 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

21. 4 hours later….

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

23. Good vs Bad ???

24. 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 better tolerated • Risks of malignant dysrhytmias

25. 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 ? • Need for ongoing CPR • Lack of spontaneous movement at 24hrs

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

27. Prevention • Children supervision • CPR courses to families with pools • Boating sobber & lifevests • Diving injuries • Caution: CAD / Seizure / Diabetics

28. 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 H2O • Majority of treatment is supportive, rewarming & not underestimate … Prevention !!! • Monitor x 6-8 hr for asymptomatic pt with normal investigations

29. Questions ? Near-Drowning