Near Drowning

Question 1

New Drowning Outcome According to WHO

Answer 1

Death

With Morbidity

With no morbidity

Question 2

Near Drowning Definition

Answer 2

When a victim survives a liquid submersion, at least temporarily

Question 3

Dry Drowning Definition

Answer 3

As soon as fluid is inhaled the bronchi constricts in response to a parasympathetic mediated reflex

Due to involuntary laryngospasm liquid does not enter the lungs

10-20% of victims maintain the laryngospasm until cardiac arrest

Have lidocaine ready for the laryngospasm

Lungs of near-dry drowning victims are normal

Question 4

Wet Drowning Definition

Answer 4

As oxygen levels fall the glottis relaxes and the liquid enters the lungs

When there is fluid in the lungs it will interfere with surfactant ability and look similar to ARDS

Question 5

Aquatic Distress

Answer 5

The “classic” picture of drowning

Often, but not always, precedes drowning

Visible, active/violent/abrupt movements

This will only last 20-60 seconds

Question 6

Instictive Drowning Response

Answer 6

• The more typical picture of drowning
• Behaviorsinstinctively taken by someone drowning (or close to drowning)
• Noiseless and subtle behaviorsthat are instinctive
  
  • Will remain in the same position and extend arms out to the sides
  • Mouth is sinking below and reappearing above the water
  • Most drowning victims cannot yell for help because they are having trouble breathing
  • Young children will struggle less than adults and can look like they are doing the dog paddle in the water

Question 7

Sequence of Drowning

Answer 7

Panic and violent struggle to return to the surface

Period of calmness and apnea

Swallowing of large amounts of fluid, followed by vomiting

Gasping inspirations and aspirations

Convulsion

Coma

Death

Question 8

SALT WATER VS FRESH WATER

Answer 8

• Pathologic changes in the lungs essentially the same
  
  • Reduction in pulmonary surfactant, alveolar injury, atelectasis, and pulmonary edema
• Salt water near-drowning victims often have more electrolyte disturbances
  
  • Also if you swallow enough fresh water you will have electrolyte imbalance

Question 9

Cold Vs. Warm Water

Answer 9

> 20 °C is warm; < 20°C cold

Cold water immersion will stimulate the diving reflex in young children (apnea, bradycardia, core-saving vasoconstriction)

Because water is an excellent conductor of body heat (cold water can cool the body 25 times faster than air in the same temperature), because evaporation further reduces an individual’s body heat and produces hypothermia

Question 10

Clean Vs. Unclean Water

Answer 10

E.g. swamp, pond, sewage, mud, chlorine pool

May have aspirated pathogens and solid material

Risk of developing pneumonia and ARDS is much higher

Question 11

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Age

Answer 11

The younger the better outcome

Younger people tend to crash hard but easier to bring back

Question 12

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Submersion Time

Answer 12

The shorter, the better

60 min is the upper limit in cold water submersion

Question 13

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Water Temperature

Answer 13

The colder the better

Range 27-70oF

Question 14

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Water Quality

Answer 14

The cleaner the better

Question 15

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Other Injuries

Answer 15

None Serious

Question 16

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Amount of Struggle

Answer 16

Less struggle the better

Question 17

FAVORABLE PROGNOSTIC FACTORS IN COLD WATER NEAR-DROWNING

Suicidal Intent

Answer 17

Lower survival rate among victims who attempted suicide than victims of accidental submersion

Question 18

Pathophysiology

Answer 18

This is in regards to wet near-drownings, as dry near drownings will have normal lungs

• Laryngospasm
• Noncardiogenic pulmonary edema
• Decreased surfactant
• Alveolar shrinkage and atelectasis
  
  • Due to the pulmonary edema
• Alveolar consolidation
• Bronchospasm
• Pulmonary hypertension
  
  • Secondary hypoxemia or inflammatory mediator release

Question 19

most important contributory factors to morbidity and mortality from drowning

Answer 19

The most important contributory factors to morbidity and mortality from drowning are hypoxemia and acidosis and the multiorgan effects of these processes.

Question 20

Central Nervous System Damage

Answer 20

• May be caused by
  
  • A primary injury (prolonged hypoxemia during episode)
  • Secondary causes (reperfusion injury, cerebral edema, seizures, arrhythmias)
  • May be a concomitant head or spinal cord injury
• CNS injury remains the major determinant of subsequent survival and long-term morbidity in cases of drowning. Two minutes after immersion, a child will lose consciousness. Irreversible brain damage usually occurs after 4-6 minutes.

Question 21

The Heart and Near Drowning

Answer 21

Can result in myocardial dysfunction

Question 22

Blood Volume Changes and Near Drowning

Answer 22

If more than 11 mL/kg of water is aspirated

Hypovolemia can result due to the fluid losses from increased capillary permeability

Question 23

Electroylte Changes and Near Drowning

Answer 23

If more than 22 mL/kg of water is aspirated

Question 24

CLINICAL MANIFESTATIONS

Answer 24

Apnea or tachypnea

Increased HR and BP

Cyanosis

Cough with frothy, white or pink sputum

Crackles on auscultation

Restrictive lung pathophysiology

Question 25

ABG

Answer 25

Resp acidosis with hypoxemia Metabolic acidosis if lactic acid present Lactic Acid may be present if there is a lot of struggling and they used a lot of energy

Question 26

CXR

Answer 26

Initial CXR may be normal; may deteriorate within the first 48-72 h Pulmonary edema and atelectasis Fluffy infiltrates; air bronchograms

Question 27

Oxygenation Indices Qs/Qt

Answer 27

Increased Because the alveoli are filled with fluid

Question 28

Oxygenation Indices DO2

Answer 28

Decreased

Question 29

Oxygenation Indices VO2

Answer 29

Normal

Question 30

Oxygenation Indices C(a-v)O2

Answer 30

Normal

Question 31

Oxygenation Indices O2ER

Answer 31

Increased

Question 32

Oxygenation Indices SvO2

Answer 32

Decreased

Question 33

PRE-HOSPITAL MANAGEMENT

Answer 33

Conserve heat/maintain body temperature Remove wet clothes, cover **All drowning victims should get 100% O2** If in cardiac arrest: CPR; establish an airway

Question 34

HOSPITAL MANAGEMENT For the Spontaneously Breathing Patient

Answer 34

Intubation and ventilation if PaO2 \< 60 mmHg on FiO2 of 0.50 or higher, or if respiratory acidosis present (\<7.25) NIPPV can be considered prior to intubation if patient is awake and alert

Question 35

Hospital Management Mechanical Ventilaition

Answer 35

ARDS/lung protective strategy with permissive hypercapnia as necessary

Question 36

Hospital Management

Answer 36

Bronchodilators (If bronchospasm is present) Manage Electroyle imbalance Surfactant Therapy Permissive Hypothermia

Question 37

Hospital Management Warming of the Patient

Answer 37

Nearly all drowning victims are hypothermic to some degree Warm IV solutions, heated lavage, Active humidity on the ventilator Heating blankets (Bear hugger) (Rare) Cardiopulmonary bypass and blood warming \*\*Rewarming may be balanced by a goal of permissive hypothermia for neuroprotection…more research needed (Especially in victims that required CPR) Resuscitation should not end even if patient does not respond until a close approximation of normal body temperature is reached

Question 38

Hospital Management Treatment for Fluid Depletion

Answer 38

Fluids, possibly inotropes

Question 39

Hospital Management Bronchoscopy

Answer 39

To remove foreign material if present (debris, vomit)

Question 40

Noncardiogenic Pulmonary Edema

Answer 40

Due to increased permeability of the membrane fluid from the pulmonary capillaries will move into the perivascular spaces, peribronchial space, alveoli, bronchioles, and bronchi (Interstitial edema) As a consequence of fluid movement, the alveolar wall and interstitial space swell, pulmonary surfactant concentration will decrease, and surface tension will increase Excessive fluid in the interstitial space causes lympathetic vessels to dilate and lymph flow to increase

Question 41

Tachypnea in Near Drowning

Answer 41

Stimulation of peripheral chemoreceptors (hypoxemia) Decreased lung compliance- Increased ventilatory rate relationship Stimulation of J receptors Anxiety (conscious patient)

Question 42

Cough with frothy, white or pink sputum in Near Drowning

Answer 42

the fluid that accumulates in the tracheobronchial tree is churned into a frothy white (sometimes blood tinged) sputum as a result of air moving into and out of the lungs (generally by means of mechanical ventilation)

Question 43

What Happends to Virutally Every Near Drowning Patient

Answer 43

Virtually every near drowning victim suffers from hypoxemia, hypercapnia, and acidosis (acute ventilatory failure) Hypoxemia will generally persists after aspiration of fluids in the airway (wet drowning) because alveolar capillary damage and continued intrapulmonary shunting The degree of hypoxemia is directly related to the amount of alveolar capillary damage