Richard Dionne MD CCFP-EM Avik Nath MD CCFP EM March 21, 2013 Submersion Injuries Richard Dionne MD CCFP-EM Avik Nath MD CCFP EM March 21, 2013

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

Diving Emergency?

Definitions Drowning: Near-drowning: AHA no longer uses terminal outcome from submersion event A process resulting in primary respiratory impairment from submersion or immersion in a liquid medium Near-drowning: AHA no longer uses Submersion Injuries (non-fatal drowning): 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

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

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

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

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

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!

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

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

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?

Management of Care Prehospital Emergency Inpatient

Prehospital On scene: Immediate Rescue Breathing (even before out of water)… Heimlich not proven … Bystander CPR (pulse check 30 sec.) DO ABC’s as opposed to CAB! Consider trauma: C-spine precautions 2000 pt study 0.5 % (11 pts only) had C-spine injury Usually obvious that injury occured Remove wet clothing, passive external rewarming (Hypothermia!)

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

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

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

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

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

4 hours later….

Factors Affecting Survival Submersion > 10 min CPR > 10 min Resuscitation > 25 min Water temo > 10 degrees Age < 3 GCS < 5 ABG < 7.1 in Ed

Good vs Bad ???

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

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

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

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

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

Questions ? Near-Drowning