Mod 7 Drowning

Question 1

Define Drowning

Answer 1

Suffocation and death due to submersion in a liquid

Question 2

Define Near-drowning

Answer 2

When a victim survives a liquid submersion, at least temporarily

Question 3

Define Dry drowning

• when does this occur?

Answer 3

Due to involuntary laryngospasm, liquid does not enter the lungs

• Lungs of near dry drowning victims are normal
• 10-20% of victims maintain the laryngospasm until cardiac arrest

Question 4

Define Wet drowning

Answer 4

As O2 levels fall, the glottis relaxes and the liquid enters the lungs

Question 5

What happens when you drown? (2)

Answer 5

• Aquatic distress
• Instinctive drowning response

Question 6

What is Aquatic distress?

Answer 6

Classic pic of drowning

• usually precedes drowning
• visible, active/violent/abrupt movments

Question 7

What is the Instinctive drowning response

• Key feature?

Answer 7

The more typical picture of drowning

• Behaviors instinctively taken by someone drowning (or close to drowning)
• Noiseless and subtle behaviors that are instinctive

Question 8

What are typical responses/events that occur during drowning or near drowning sequences? (7)

Answer 8

1. Panic/violent struggle to return to surface
2. Period of calmness and apnea
3. Swallowing large amounts of fluids, followed by vomiting
4. Gasping inspirations and aspirations
5. Convulsions
6. Coma
7. Death

Question 9

What are 3 things to consider for Near drowning?

Answer 9

1. Salt vs fresh water
2. Cold vs warm water
3. Clean vs unclean water

Question 10

Why is salt water near drowning more concerning than in fresh water?

Answer 10

Salt water near drowning victims have more electrolyte disturbances

• Pathologic changes are almost the same.

Question 11

What is considered warm vs cold water?

Answer 11

• > 20 °C is warm
• < 20°C cold

Question 12

Does colder or warmer water drowning yield better survival?

• why?

Answer 12

Cold water slows metabolism; means they require less O2

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

Question 13

What factors do you need to consider with unclean water near drowning?

Answer 13

May have aspirated pathogens and solid material

Question 14

What risks develop with unclean water near drownings?

• Think pathologies

Answer 14

Risk of developing pneumonia and ARDS is much higher

Question 15

What factors increase survival prognosis in cold water near drownings? (8)

Answer 15

1. Age
2. Submersion time
3. Water temperature
4. Water quality
5. Other injuries
6. Amount of struggle
7. CPR quality
8. Suicidal intent

Question 16

What is the upper limit for cold water near drowning prognosis’s ?

Answer 16

60 mins is the upper limit for cold water drownings

• The shorter, the better

Question 17

Pathophysiology of Wet Near Drowning? (8)

• AKA what happens to the body as a result?

Answer 17

• Laryngospasm
• noncardiogenic pulmonary edema
• Decreased surfactant
• Alveolar shrinkage and atelectasis
• Alveolar consolidation
• Bronchospasm
• Pulmonary hypertension
• CNS damage

Question 18

What are the mechanisms of noncardiogenic pulmonary edema that’s involved with wet near drowning? (2)

Answer 18

1. Interstitial edema; fluid moves into the capillaries into the perivascular and peribronchial spaces, alveolar walls, bronchi/bronchioles, and interstitial spaces
2. Lymph vessels dilate w/increased flow through the lymph system

Question 19

What are the mechanisms of Pulmonary Hypertension that’s involved with wet near drowning?

Answer 19

Secondary hypoxemia or inflammatory mediator release

Question 20

Why does surfactant decrease with near drowning?

Answer 20

Surfactant mixes w/inhaled fluids creating frothy secretions.

• Then we suction it out…

Question 21

What would cause injury to the CNS because of near drowning? (3)

• Break up each cause into flash cards

Answer 21

1. Primary injury involves prolonged hypoxemia during episode
2. Secondary causes involve reperfusion injury, cerebral edema, seizures, arrhythmias
3. May be concomitant head or spinal cord injury

Question 22

What do primary injuries that cause CNS damage during near drowning generally entail in terms of pathology/affect?

• AKA What is the primary cause of injury that causes CNS damage
• Need to edit the phrasing

Answer 22

Prolonged hypoxemia during episode

Question 23

What are secondary causes that may cause CNS damage in near drownings? (4)

Answer 23

• Reperfusion injury
• Cerebral edema
• Seizures
• Arrhthmias

Question 24

When does irreversible brain damage usually occur in near drowning events?

Answer 24

after 4-6 minutes after immersion

Question 25

When do children lose consciousness in immersion events?

Answer 25

Two minutes after immersion

Question 26

How is the heart affected by near drowning events?

Answer 26

Myocardial dysfunction

Question 27

How is blood volume affected by near drownings? - When do changes occur?

Answer 27

Hypovolemia can result due to fluid losses from increased capillary permeability. - occurs if more than 11ml/kg of water is aspirated

Question 28

When do electrolyte changes occur during near drowning events?

Answer 28

If more than 22ml/kg of water is aspirated

Question 29

Clinical Manifestations of drowning? (6)

Answer 29

- Apnea or tachypnea - Increased HR and BP - Cyanosis - Cough w/frothy, white, or pink sputum - crackles on auscultation - Restrictive lung pathophysiology

Question 30

Clinical manifestations of drowning: What would you expect on a ABG?

Answer 30

Resp acidosis w/hypoxemia **OR** Metabolic acidosis if lactic acid present

Question 31

Clinical manifestations of drowning: What would you expect on a CxR?

Answer 31

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

Question 32

Left off @slide 14

Question 33

What are pre-hospital treatments of near drowning events?

Answer 33

- **Conserve heat**/maintain body temperature (remove wet clothes/cover) - All drowning victims should get **100% O2** - If in cardiac arrest; **CPR; Establish airway**

Question 34

What are hospital treatments of near drowning events if the patient is still spontaneously breathing?

Answer 34

- Intubate and ventilate if PaO2 < 60mmHg on FiO2 > 0.50 or if resp acidosis present (<7.25) - NIPPV can be considered prior to intubation if awake and alert

Question 35

What are airway management strategies and treatments in the hospital for victims of near drowning events? (3)

Answer 35

1. Intubate and vent (or NIPPV if spontaneously breathing) 2. Follow Mech ventilation ARDS/lung protective strategies w/permissive hypercapnia as necessary 3. Bronchodilators (if bronchospasm present)

Question 36

What are the primary treatments used for victims of near drowning to address drowning (not direct airway management treatments) (7)

Answer 36

1. Warming of patient 2. Address volume depletion 3. Manage electrolyte imbalances 4. Bronchoscopy 5. ECO 6. Surfactant therapy 7. Prophylactic antibiotics or steroids

Question 37

What considerations need to be kept in mind when rewarming near drowning victims?

Answer 37

Rewarming may be balanced by a goal of permissive hypothermia for neuroprotection

Question 38

How is fluid volume depletion addressed?

Answer 38

Fluids and possibly inotropes

Question 39

What is the purpose of a Bronchoscopy in addressing near drowning victims?

Answer 39

To remove foreign material if present (debris or vomit)

Question 40

What can be used to rewarm a patient?

Answer 40

Warm IV solutions, heated lavage, Active humidity on the ventilator Heating blankets (Bear hugger)

Question 41

What is the diving reflex?

Answer 41

physiological response that causes peripheral vasoconstriction to prioritize blood flow to vital organs.