Submersion Injuries

Richard Dionne MD CCFP-EMAssistant Professor Emergency Medicine

Ottawa Hospital-University of OttawaAssistant Medical Director

Ottawa Base Hospital Paramedic ProgramFellowship 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 hypoxiaRespiratory acidosis, ARDS

Cardiovascular collapseNeuronal 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