DrowningNEJM Review

NEJM 2012;366:2102-10

• 0.7% all deaths worldwide

• >500,000 deaths/year

• Leading cause death boys 5-14yrs

• Second leading cause of death due to injuries 1-4yrs

• 25% are > 14y/o

• Males > Females (4:1)

• Alcohol involved

• Epilepsy

How many people drowned in NZ in 2010?

87 people died of drowning in New Zealand during 2010. This is the lowest annual toll since 1980. Three regions (Waikato, Tasman and West Coast) had increased drowning tolls from 2009.

160 people were hospitalised due to immersion incidents in New Zealand during 2010. This is the highest annual toll since 2003. The five year average is 136 hospitalisations per year.

Deaths Auckland – 18 NZ - 87

Hospitalisations 49 160

Deaths *Watersafety NZ

Site of accidentHospitalised cases – does it really matter to us?

*Watersafety NZ

Definitions“Drowning is the process of experiencing

respiratory impairment from submersion/immersion in liquid” WHO 2002

Respiratory impairment as airway goes below the surface (submersion) or water splashes over the face (immersion)

Rescue at any time, process of drowning interrupted nonfatal drowning

Death as a result of drowning fatal drowning

Water rescue: Any submersion or immersion incident w/o evidence of resp impairment

Terms to avoidNear drowning

Dry or wet drowning

Secondary drowning

Active and passive drowning

Delayed onset of respiratory distress

From Auerbach: Wilderness Medicine, 5th ed. ( Submersion or near-drowning) Fig 68.4.

Cold Water DrowningImmersion syndrome (water temp >5o less than

body temp)Death shortly after cold water immersion 2o

vagally induced VF arrest (?diving reflex)

Cold Water shockOn exposure to cold water, uncontrollable

gasping for approx 1 min that will result in aspiration if head submerged

Catecholamine surge that may precipitate arrythmia

Cooling peripheries decrease nerve conduction and impair muscle co-ordination and impair self rescue

Immersion hypothermia

RESPIRATORY EFFECTS

Which of the following factors is most relevant in history?

Fresh Water/Salt Water/Polluted water

How many mls/kg does the average submersion injury aspirate ?

How many mls/kg aspirate of salt water causes alteration of

blood volume?

electrolytes?

Orlowski et al instilled differing NaCl conc into dog ETT tubes

Pulmonary Injury

Effects of alveolar fluid

Effects of alveolar membrane damage

Effects of vascular endothelial damage

Inflammatory response

Nasty Water• Pollutants

– Hydrocarbons (Low viscosity /High Volatility)

– Heavy Metals– Particulates

• Microorganisms– Gram Negative

• Pseudomonas, Aeromonas, Burkholderia, Legionella

– Gram Positive• Streptococci and Staphylococci

(from mouth)

• Fungi– Pseudoallallescheria boydii

• Prophylactic treatment not indicated (maybe if raw sewage)

Pulmonary Aspiration (1-3mL/kg) can reduce gas exchange

Bronchospasm 

Chemical pneumonitis• Pulmonary vasoconstriction/hypertension (vagally

mediated)• Surfactant destruction

–  alveolar instability, atelectasis, and decreased compliance, with marked ventilation/perfusion (V/Q) mismatching

• Acute respiratory distress syndrome (ARDS) 

Pneumonia Aeromonas, Burkholderia, and Pseudallescheria

Fibrosis, restrictive lung disease, and decreased diffusion capacity

Cardiovascular EffectsHypotension

Shock, acidosis, hypovolemia (natriuresis), autonomic instability

ArrhythmiasAsystole (55%), Ventricular tachycardia/fibrillation (29%)Bradycardia (16%)BrugadaLong-QT syndromes

Other systemsNeurological

Neurologic asphyxia Seizure, coma, death Encephalopathy Cardiocerebral protection? (Remember head trauma/ c-spine)

Renal Natriuresis Acute renal failure Rhabdomyolysis

Electrolytes/Hem Normal aspiration of 3-4ml/kg Changes in blood volume at

11ml/kg Haemolysis at 22ml/kg (1.5L)

Rescue and in-water resuscitation

Areas with lifeguards:

<6% require medical attention

0.5% require CPR

Untrained resuers need to avoid drowning themselves

Conscious: Take to land and initiate BLS

Unconscious: Ventilation alone.

C-spine injuries <0.5%

Initial Resuscitation on land

Rescue ventilation essential

Cardiac arrest due primarily to lack of oxygenation so CPR should follow ABC approach

5 initial rescue breaths

30:2

Most frequent complication is regurgitation of stomach contents. 65% rescue breathing alone and 85% who require CPR

Avoid abdominal thrusts or placement head down

ADVANCED PREHOSPITAL CARE

Obvious deathSubmerged for >1 hour

Normothermia (>30°C) with asystole with CPR >30min

Rigor mortis

Dependent lividity

No apparent CNS function

CARE IN THE ED

Scoring Systems on Hospital Arrival

The simple approach

Asymptomatic

Symptomatic

Critical

Obviously dead

Modell & Conn 1984 – in ED within 1 hr of rescue (paeds)

Category Description GCS Neurologically Intact (%)

A Awake – fully orientated

14-15 100

B Blunted- rousable, purposeful to pain

8-13 100

C Comatose- not rousable, abnormal response to pain

6-7 >90

C1 Flexor response to pain

5 >90

C2 Extensor response to pain

4 >90

C3 Flaccid 3 <20

C4 Arrested 3 <20

Asymptomatic patientNo comorbidities

If at 4 - 6 hours:CXR, ABG normal

Normal vitals on air

Remain ASx = discharge with advice

If aspirated potential for delayed deterioration

Symptomatic PatientConsider foreign material in airway (approx. 50% of

surf submersions)

Salbutamol / Ipratoprium nebs for bronchospasm

NG placement on free drainage may improve ventilatory distress

High risk for vomiting and gastric content aspiration

Suction +++

Most will require fluid resuscitation secondary to diuresis

Beware hypothermia and trauma

HypothermiaCommon following drowning

Arrhythmias more common, can be refractory at temps < 30°C – limit defibrillation shocks to 3

Dose interval of resuscitation drugs is doubles at temps between 30 and 35°C

Continue resuscitation until core temp at least 32°C

Generally allow temp to rise by 0.25-0.5°C /hr to reduce haemodynamic instability

Vasodilation during rewarming BP, large volumes of warmed IVF

Therapeutic hypothermia

Treatment in the ICUIndications for Intubation:

Decreased GCS for airway protection

Unable to maintain PaO2 > 90 on high flow, non-rebreather mask

Unable to maintain PaCO2 < 45

Respiratory:

Tend to recover much faster than pts with ARDS

Late pulmonary sequelae uncommon

Wean ventilation after 24hrs

VentilationMost text books will support a trial of NIV if blood pressure

and GCS appropriate, however there are no literature to support its use

Start low and titrate up

volume support

Vt low – 6mls/kg

PEEP 5-10 cm H20 only if PaO2 < 60 on FiO2 <0.6

Ventilate for 24 hours to allow regeneration of surfactant

PneumoniaNo prophylactic

antibiotics

No prophylactic steroids

If starting Abx, start broad

Circulatory:

Oxygenation

Rapid crystalloid infusion

Normalisation of body temp

Early cardiac dysfunction in Grade 4-6

No evidence for specific fluid therapy, diuretics or water restriction

Neurologic:

Aim for normal Glc, paO2, pCO2

Induced hypothermia – core temp 32-34°C may be neuroprotective

Recent reports on drowning documented good outcomes with the use of therapeutic induction of hypothermia after resuscitation, despite a predicted poor outcome

Vanden et al. Part 12: cardiac arrest in special situations: drowning:2010 American Heart AssociationGuidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2010;122:Suppl 3:S847-8

Guenether U et al.Extended theraeutic hypothermia for several days during extra-corporeal membrane-oxygenation after drowning and cardiac arrest: two cases of survival with no neurological sequelae. Resuscitation 2009;80:379-81

Unusual ComplicationsSIRS after resuscitation has been reported

Should not be misinterpreted as infection

Sepsis and DIC in first 72hrs

Renal insufficiency or failure rare

Prognostic factors, patients <20 years Quan L, Kinder D. Pediatric submersions: prehospital predictors of outcome [see comments]. Pediatrics

1992;90:909±913. & Cummings P, Quan L. Trends in unintentional drowning: the role of alcohol and medical care. JAMA 1999;281:2198±2202.

100% mortalitySubmersion duration > 25 min Resuscitation duration >25 minPulseless cardiac arrest on arrival to ED

OtherVT/VF on initial ECG (93%)Fixed pupils in ED (89%)Severe acidosis (89%)Respiratory arrest in ED (87%)Unresponsive in ED

Who Lives or DiesGood Prognostic Indicators

Short submersion BLS/ALS on scene Good response to initial resuscitation Alert on admission Older child or adult Water temp < 5-10°C

Bad Prognostic Indicators Submersion > 25 minutes Cardiac arrest requiring > 25 minutes of ALS Ongoing CPR in ED Fixed, dilated pupils in ED pH < 7.1 Age < 3 y/o GCS < 5 in ED

Other Ineffective Treatments

No head down positioning

No Heimlich maneuver

No diuretics

No prophylactic antibiotics

No steroids

1-10-1

Beware of Diving