Submersion Injuries

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 2nd, 2008

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

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

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 • =>asystole and VF • Resultant LOC leads to drowning

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

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

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

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!

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.) • Consider trauma: C-spine precautions • Remove wet clothing, passive exernal rewarming (Hypothermia!)

Emergency Department • ABC’s • Early airway management • Cardiac monitor, CORE (rectal) temp • Immediate rewarming (Hypothermia) • 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, rhabdomyolysis • 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

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

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

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

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

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

Submersion Injuries